WO2016089269A1

WO2016089269A1 - Methods and devices to transmit channel state information in a multi-point wireless communication system

Info

Publication number: WO2016089269A1
Application number: PCT/SE2014/051462
Authority: WO
Inventors: Sairamesh Nammi
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2014-12-05
Filing date: 2014-12-05
Publication date: 2016-06-09

Abstract

There is provided a method performed in a first network node, the first network node controlling at least one HSDPA radio link in a cellular communications network and the cellular network supporting HSDPA multiflow operation, the method comprises receiving CSI feedback at a receiving time instance and decoding the CSI feedback only if the receiving time instance and a first configured time instance coincide. The first configured time instance is based on a first cell specific parameter. The method finally determines whether the received CSI feedback is composite or non-composite.

Description

METHODS AND DEVICES TO TRANSMIT CHANNEL STATE INFORMATION IN A MULTI-POINT WIRELESS COMMUNICATION SYSTEM

TECHNICAL FIELD

The present invention relates to the transmission of channel state information in a cellular communications network configured for HSDPA multiflow or multipoint transmission.

BACKGROUND

In order to increase the cell edge throughput in HSDPA, HSDPA multiflow operation (MF-HSDPA or MF operation or multipoint operation or just multiflow operation) was standardized in 3GPP Release 1 1 .

HSDPA multiflow operation is characterized as simultaneous reception of HS- DSCH transport channels in the CELL_DCH state, where two HS-DSCH transport channels may reside at the same frequency and belong to different cells but either to same or different Node Bs. In order for HSDPA to work efficiently, the user equipment (UE) has to feedback information about the perceived downlink radio quality to the network through UL signalling.

The feedback signaling may comprise Hybrid-ARQ Acknowledgement (HARQ- ACK) and Channel-Quality Indication (CQI). The feedback is sent on an uplink channel, the HS-DPCCH. In case of HSDPA multiflow operation, the feedback signalling from one UE may increase due to the fact that feedback may be requested for two or more HS-PDSCH channels.

However, in HSDPA multiflow, there is only one common HS-DPCCH channel.

In 3GPP this has been solved by introducing a composite feedback which may be achieved by concatenating the bit representation of the CSI before block encoding the bit representation. This increases the CSI feedback per HS-DPCCH subframe at expense of the robustness of the feedback.

At the cell edge of very large cells, or in some soft handover situations the HS- DPCCH quality at a nodeB may not be sufficient to correctly decode the CSI feedback on the HS-DPCCH. This means that the CSI feedback may not be received correctly and consequently, due to the incorrect CSI, the downlink throughput may therefore be significantly reduced.

One way of overcoming this problem is to enable shorter CSI reporting periods and repetition of the CSI feedback, in order more reliably receive correct CSI. There are parameters specified in 3GPP TS 25.331 , which can be used to configure the CSI reporting for the different downlink radio links.

However, with shorter reporting periods or repetition of CSI feedback, more UL signaling on e.g. HS-DPCCH from the wireless device, is required, which in turn can cause a reduced system throughput in uplink, i.e. uplink capacity. SUMMARY

It is one objective of the present disclosure, to provide a flexible approach to transfer CSI feedback, with the purpose to improve the radio spectrum utilization, and consequently this may increase the capacity of a wireless network, in particular on the uplink. The objective may be achieved by the methods, devices and arrangements described herein.

According to one aspect, there is disclosed a method, performed in a wireless device, the wireless device being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network. The method comprises receiving at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link. The method further comprises determining, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide and sending CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else sending CSI feedback as non-composite feedback.

According to another aspect, a wireless device is adapted to being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, the wireless device is further adapted to receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link. The wireless device is further adapted to determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide. The wireless device is further adapted to send CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else the wireless device is configured to send CSI feedback as non-composite feedback.

According to another aspect, a method is performed by a first network node, the first network node controlling at least one HSDPA radio link in a cellular

communications network and the cellular network supporting HSDPA multiflow operation and the method comprises receiving CSI feedback at a receiving time instance. The method also comprises decoding the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter. The method further comprises determining, whether the received CSI feedback is composite or non- composite.

According to another aspect, a first network node is adapted and/or configured to control at least one HSDPA radio link in a cellular communications network and the cellular network supports HSDPA multiflow operation, the network node is further configured to and/or adapted to receive CSI feedback at a receiving time instance. The first network node is also adapted and/or configured to decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter. The first network node is further adapted and/or configured to determine whether the received CSI feedback is composite or non-composite.

According to another aspect, there is disclosed a first computer program

comprising instructions which, when executed on a processing circuitry, cause the processing circuitry to carry out and/or control any methods, performed in or by the wireless device, disclosed herein.

According to yet another aspect, there is disclosed a second computer program comprising instructions which, when executed on a processing circuitry, cause the processing circuitry to carry out and/or control any methods, performed in or by the first network node, disclosed herein. According to another aspect, there is disclosed a first carrier containing the first computer program, wherein the first carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium.

According to another aspect, there is disclosed a second carrier containing the second computer program, wherein the first carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium. The above network node, wireless device, methods, computer programs and carriers therein may be implemented and configured according to different optional embodiments to accomplish further features and benefits, to be described below.

BRIEF DESCRIPTION OF FIGURES

The solution will now be described in more detail by means of exemplary embodiments and with reference to the accompanying drawings, in which:

Fig. 1 Schematic illustration of an example of a cellular communication network (100) serving a wireless device (200) in HSDPA multiflow operation.

Fig. 2 Illustrates a message sequence chart for data transmission in a multiflow operation in a cellular communications network.

Fig. 3 Illustration of an example of the HS-DPCCH structure for composite CSI feedback for multiflow operation in a cellular communications network.

Fig 4 Illustration of an example of the HS-DPCCH structure for non- composite CSI feedback. Fig. 4a Illustration of the relative sequential timing of measurement of CSI, CSI feedback reporting, scheduling based on CSI feedback and sending of data on the different channels in relation to CSI feedback.

Fig. 4b Illustration of how the sending time instances on the HS-DPCCH may be determined in a wireless device in multiflow operation. Fig. 5 An example of how the CQI can be concatenated prior to encode composite CSI feedback related to CQI.

Fig. 6 Illustration of how the parameters related to CSI feedback (CQI feedback cycle, CQI repetition factor, and HARQ-ACK repetition factor) influence HS-DPCCH transmissions. In the example the CQI feedback cycle is 4 ms, the CQI repetition factor is 2, and the HARQ-ACK repetition factor is 3.

Fig. 6a States an example of parameters related to configuring CSI feedback.

Fig. 7 Illustration of how the parameters related to CSI feedback, influence the HS-DPCCH transmissions when the parameters are different between the cells in HSDPA multiflow transmission.

Fig. 8 Another illustration of how the parameters related to CSI feedback, influence the HS-DPCCH transmissions when the parameters are different between the cells in HSDPA multiflow transmission. Fig. 8a Illustration of the CQI relative timing and coding on HS-DPCCH when a wireless device is operation HSDPA multiflow and parameters related to CSI feedback are different in the serving- and assisting serving HS-DSCH cells.

Fig. 9 A method in a wireless device.

Fig. 10 A method in a network node. Fig. 1 1 Intra-NodeB HSDPA multiflow.

Fig. 12 Inter-NodeB HSDPA multiflow.

Fig. 13 A handover sequence with an evaluation on whether to activate initiate HSDPA multiflow for a wireless device.

Fig. 14/16 An example of a wireless device. Fig. 15/17 An example of a network node. DETAILED DESCRIPTION

Aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings.

The terminology used herein is for the purpose of describing particular aspects of the disclosure only, and is not intended to limit the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The term "multiflow operation" describes a mode of operation with two

simultaneous HS-DSCH transport channels and/or HSDPA radio links, on the same frequency. The HS-DSCH transport channels may belong to the same or different Node Bs. Other terminology with the same meaning in this disclosure are, MF-HSDPA or MF operation or multipoint operation or HSDPA multiflow operation or just multiflow operation.

In the context of this description, an HSDPA radio link may be a radio link for wireless communication between a wireless device and a wireless communication network. The HSDPA radio link may have a downlink direction and an uplink direction, wherein the uplink direction may be used by the wireless device to transmit user data and/or control data such as e.g. RRC signaling or CSI feedback. The downlink direction may be used by the network to transmit e.g. user data and/or control data such as e.g. scheduling data and/or measurement control data such as e.g. cell specific parameters. Cell specific parameters, in this disclosure may be e.g. CQI feedback cycle (k) and/or CQI repetition factor

(N_cqi_transmit) and/or HARQ-ACK repetition factor (N_acknack_transmit) as they are specified in 3GPP spec TS25.331 v1 1 .2.0. These parameters may in this disclosure be a first- and a second cell specific parameter. The cell specific parameters may be used to configure a sending time instance. Configuring a sending time instance in a wireless device may be defined as the wireless device determining one or several subframes and/or timeslots and/or slots on the HS- DPCCH based on one or several cell specific parameters. In HSDPA multiflow operation the configuring of a sending time instance may be done per HSDPA radio link.

CSI may comprise CQI (Channel Quality Indicator) and/or HARQ-ACK (Hybrid ARQ Acknowledgement). In HSDPA, the CSI may be defined as the bit

representation or the value of e.g. the estimated and/or measured SINR

measurement in case of CQI or as the bit representation of the success of receiving a data packet on the HS-PDSCH. CSI feedback, on the other hand, may be defined as a certain number of encoded bits wherein the bits may be generated by encoding of a CSI value and/or bit representation. The CSI feedback may be further defined as fitting into a certain subframe and time slot on the common HS- DPCCH. As an example, the CSI feedback for CQI may be encoded into 20 bits and sent in slot 2 and 3 in an HS-DPCCH subframe whereas another example of CSI feedback for HARQ-ACK may be encoded into 10 bits and sent in slot 1 in an HS-DPCCH subframe.

In HSDPA multiflow operation there may be several HSDPA radio links associated with one wireless device. Each HSDPA radio link in HSDPA multiflow operation may be associated with a CSI feedback. A sending time instance for CSI may be configured per HSDPA radio link.

CQI may be sent periodically or aperiodically whereas HARQ-ACK may only be sent in response to a received downlink data packet.

Cell specific parameters may be used to configure the wireless device to determine a first sending time instance for a first HSDPA radio link and second sending time instance. In figure 4b, it is illustrated how a sending time instance for CQI is determined based on the cell specific parameters k and N_cqi_transmit. A wireless device (200) may be adapted to have timing relation, in particular a well-defined and/or synchronized timing relation, between the HS-DPCCH subframes and the CPICH in order to be able to transmit CSI feedback in the proper time slot after having measured on the CPICH. The wireless device may also be adapted to know the timing relation between the different CPICH in different cells and the HS-DPCCH. The wireless device may also be adapted to know the timing relation between the HS-PDSCH and the HS-DPCCH.

Composite CSI feedback or composite feedback may comprise a jointly encoded CSI feedback, wherein each CSI feedback is related to different HSDPA radio links in e.g. HSDPA multiflow operation.

Composite CSI feedback may be sent from the wireless device when the cell specific parameters a wireless device has determined that the sending time instance for a first HSDPA radio link coincide with a sending time instance for a second HSDPA radio link.

In figure 8a there is illustrated an example of composite CSI feedback. Based on the cell specific parameters the wireless device may determine that composite CSI feedback related to CQI (CQI_C) may be sent in HS-DPCCH subframe 1 and subframe 5. The wireless device may also determine, based on cell specific parameters, that non-composite CSI feedback related to CQI (CQM ), shall be sent and/or transmitted in HS-DPCCH subframes 2, 3 and 4.

A CSI feedback may be blindly decoded. The blind part in the decoding is caused by not knowing whether the CSI feedback is composite or non-composite.

Consequently, blindly decoding CSI feedback may comprise decoding of CSI feedback and obtain at least one bit representation and/or CSI value, reflecting the requested CSI for one or both HSDPA radio links and/or cells and/or network nodes. The value obtained after the decoding can be compared with previous values of the output from blindly decoding CSI feedback. It is disclosed, in a first aspect, a method performed in a wireless device, the wireless device being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, wherein the method comprises receiving (S1 ) at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending CSI feedback related to the second HSDPA radio link. The method further comprises determining (S2), based on the first- and second cell specific parameters, if the first- and second sending time instances coincide, sending (S3') CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else sending (S3) CSI feedback as non-composite feedback.

Moreover, there is disclosed a method wherein the non-composite feedback is related to only one of the first- and the second HSDPA radio links.

In another example method the non-composite feedback may be encoded with an equal amount of bits as the composite feedback.

In yet another variant of the method, the non-composite CSI feedback is encoded such that the ratio between the number of information bits and the number of encoding bits is lower compared to the composite feedback.

It is also disclosed an additional variant of the method, wherein the non-composite CSI feedback is encoded using a (20,5) block code and/or a (10, 1 ) block code.

A method according to any of the previous claims, wherein the CSI feedback comprises CQI and/or HARQ-ACK. It may be further considered a method wherein the at least first- and second cell specific parameters comprises one of CQI feedback cycle (k) and/or CQI repetition factor (N_cqi_transmit) and/or HARQ-ACK repetition factor (N_acknack_transmit)

It is additionally and /or alternatively disclosed method wherein the composite feedback is related to the first- and the second HSDPA radio links.

Further there is disclosed a wireless device adapted to being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, the wireless device is further adapted to

- receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link

- determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide

- send CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else

- send CSI feedback as non-composite feedback

In another example, a wireless device is disclosed wherein the non-composite CSI feedback is related to only one of the first- and the second HSDPA radio links.

In yet another example a wireless device is disclosed wherein the non-composite CSI feedback is encoded with an equal amount of bits as the composite CSI feedback . In another variant, it is disclosed, a wireless device wherein the non-composite feedback is encoded such that the minimum Hamming distance is decreased compared to composite feedback.

Additionally, a wireless device is disclosed wherein the non-composite feedback is encoded using a (20,5) block code and/or a (10, 1 ) block code.

In yet another example it can be disclosed a wireless device wherein the CSI feedback comprises CQI and/or HARQ-ACK.

The wireless device may also be adapted to receive at least first- and second cell specific parameters wherein the cell specific parameters may comprise one or several of CQI feedback cycle (k) and/or CQI repetition factor (N_cqi_transmit) and /or HARQ-ACK repetition factor (N_acknack_transmit).

In another example, a method performed in a first network node is disclosed. The first network node controlling at least one HSDPA radio link in a cellular communications network and the cellular network supporting HSDPA multiflow operation, the method comprises:

- receiving (S1 1 ) CSI feedback at a receiving time instance

- decoding (S12) the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter - determining (S13), whether the received CSI feedback is composite or non- composite

In order to decode the CSI feedback, a network node and/or a NodeB may figure out whether received CSI feedback on HS-DPCCH is composite- or non- composite CSI feedback. As one example the network node may blindly decode the CSI feedback and test the obtained value against an expected value.

In another example the determining may be based on blind decoding of the CSI feedback. In yet another variant of the method, the blind decoding is performed by applying a first- and/or a second decoding method

In additional variants the first decoding method may be associated with the non- composite feedback and the second decoding method may be associated with the composite feedback In another variant, the method may use the decoded CSI feedback to verify and/or check whether the obtained CSI value is likely to be correct, when tested against a condition.

In another example, a test may be to check if the decoded CSI feedback is:

- within an expected range and/or - greater than an expected value

Additionally, the method may perform the test wherein the expected value and/or the expected range, is based on previously decoded CSI feedback.

Additionally and or alternatively it may be considered a method wherein the determining (S13) is based on at least one of: - the first configured time instance

- a second configured time instance being based on a second cell specific

parameter The method in, which, the determining (S13), further comprises determining that CSI feedback is non-composite feedback, if the second configured time instance does not coincide with the first configured time instance.

The method wherein the first- and second cell specific parameters are

communicated to the first network node from, or via, at least one of a second network node (RNC), the first network node and/or the wireless device

The method may also be considered wherein the first- and second cell specific parameters comprise one of CQI feedback cycle (k) and/or CQI repetition factor (N_cqi_transmit) and/or HARQ-ACK repetition factor (N_acknack_transmit) It is disclosed a first network node (NB), which is configured to control at least one HSDPA radio link in a cellular communications network and the cellular network supports HSDPA multiflow operation, the network node is further configured to and/or adapted to receive CSI feedback at a receiving time instance and decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter and determine whether the received CSI feedback is composite or non-composite

In certain circumstances the first network node is further adapted and/or configured to determine whether the received CSI feedback is composite or non- composite, based on blind decoding of the CSI feedback.

The first network node may also be considered wherein the first network node may be adapted to test whether the decoded CSI feedback fulfils a condition and additionally and/or alternatively wherein the first network node is adapted to determine if the decoded value is within a range and/or the decoded value is above an expected value. In another variant, a first network node according to any of claims 31 -34, wherein the first network node is adapted and/or configured to determine, if CSI feedback is composite or non-composite based on at least one of the first configured time instance and a second configured time instance being based on a second cell specific parameter

A first network node according, wherein the first network node first network node is configured and/or adapted to determine that CSI feedback is non-composite feedback, if the second configured time instance does not coincide with the first configured time instance. The first network node according, wherein the first network node may be also adapted to receive the first- and second cell specific parameters from, or via, at least one of a second network node (RNC) and/or the first network node and/or the wireless device.

The first network node according to previous examples, wherein the first network node is adapted to obtain and/or receive the first- and second cell specific parameters, the parameters comprise one of CQI feedback cycle (k) and/or CQI repetition factor (N_cqi_transmit) and/or HARQ-ACK repetition factor

(N_acknack_transmit).

Figure 1 illustrates a wireless communication system 100 which supports multiflow operation. Multiflow operation is a mode of operation with two simultaneous HSDPA radio links or HS-DSCH radio links (401 ,402) per carrier frequency (f1 ) where the HSDPA radio links may belong to the to the same or different network nodes (101 , 102).

In figure 1 there are several cells (B1 , B2, B3, C1 , C2, C3) associated with a respective network node (101 , 102). Note: In figure 1 , that cell B1 and C1 are also referred to as 301 and 302 respectively.

The cells involved in the multiflow operation are called serving- and/or assisting serving HS-DSCH cells (301 , 302) and they are the cells associated with the access point and/or NodeB and/or network node, which is performing transmission and reception of the serving- and/or assisting serving HS-DSCH radio links (401 , 402) for a given UE. The serving HS-DSCH cell (301 ) may be referred to as primary- and/or first- and/or second- and or assisting serving HS-DSCH cell. As an example of HSDPA multiflow operation in figure 1 , a wireless device 200 is connected to a wireless communication network 100 via a first HSDPA radio link 402 and a second HSDPA radio link 402. The first HSDPA radio link is controlled by a first network node 101 and the second HSDPA radio is controlled by a second network node 102. The first network node controls a first cell 301 which is associated with the first HSDPA radio link whereas the second network node 102 is associated a second cell 302. Each cell may host cell specific parameters to control an intensity of a reporting period of channel state information feedback. In this example, when two different networks nodes (101 and 102) are involved, the HSDA multiflow operation is said to be inter-NodeB multiflow operation. It shall also be noted that multiflow operation may be carried out with the first- and the second HSDPA radio links within the same network node but with the two HSDPA radio links in different cells. This scenario may be referred to as intra-NodeB multiflow operation.

A wireless device (200) is connected to the network with a first- and a second HSDPA radio links associated with a cell 301 and 302 wherein the serving- (301 ) and assisting serving (302) HS-DSCH cells may also be a first and a second cell, respectively. The transmission and reception between the wireless device (200) and the cells is performed on the serving- and assisting serving HS-DSCH radio links (401 , 402). The HSDPA radio link may be used for downlink transmission from and/or via the serving- and assisting serving HS-DSCH cells (301 , 302) and/or network nodes (101 , 102) is performed on their respective HSDPA radio link (401 , 402). The channel state information feedback may be sent on a common feedback channel - the HS-DPCCH.

Figure 2 shows a sequence chart for data transmission in a multiflow operation system. Note that P-Node B indicates the primary Node B or serving HS-DSCH NodeB or first network node (101 ) which is associated with serving HS-DSCH cell (301 ) and the S-Node B indicates the secondary Node B or assisting serving HS- DSCH node B or second network node (102) and is associated with the assisting serving HS-DSCH cell (302). The P-NodeB (101 ) and the S-NodeB (102) in the figure may be the same network node in case of intra-Node B multiflow operation. A pilot channel CPICH (P-CPICH) is used to send pilot signals. These pilot signals are sent from each network node and/or cell. Note that the pilot signals differ by different scrambling codes in each cell. From the individual pilot signals, the UE estimates the SINR by performing measurements. The estimated SINR may be represented by five bits. These five bits may represent an integer vale (0-31 ) for which a higher value indicates a better channel quality. The representation of the channel quality may be called channel quality information (CQI) and may be part of channel state information (CSI) feedback.

If the wireless device (200) is in HSDPA multiflow operation, the CQI may be sent through a common feedback channel, HS-DPCCH. The same HS-DPCCH is received by or in both serving- and assisting serving HS-DSCH cells over its respective HSDPA radio links. The HS-DPCCH structure is shown in figure 3.

In figure 4b a complementary view of the relative sequential timing of

measurement of CSI, CSI feedback reporting, scheduling based on CSI feedback and sending of data on the different channels in relation to CSI feedback, can be found.

The HARQ-ACK may be feedback sent by the wireless device (200) in response to receiving a downlink data packet on the HS-DSCH channel on the HSDPA radio link. The HARQ-ACK may indicate whether the downlink data packet was received successfully or not. If the wireless device is in HSDPA multiflow operation, the HARQ-ACK may be sent through a common feedback channel, HS-DPCCH. The same HS-DPCCH is received by or in both serving- and assisting serving HS- DSCH cells over its respective HSDPA radio links. The HS-DPCCH structure is shown in figure 3.

The first part of a joint encoding operation of CQI1 and CQI2 may be performed as is shown in Figure 5, where the 5 bits of individual CQI (CQI1 ) of the serving HS- DSCH cell is concatenated with the 5 bits of CQI (CQI2) of the assisting serving HS-DSCH cell. After the operation shown in figure 5, these 10 bits are passed through the block encoder to form the 20 coded bits.

Once the serving HS-DSCH cell (301 ) and/or first network node (101 ) and the assisting serving HS-DSCH cell (302) and/or second network node (102) receive the composite CQI feedback (502), each cell (301 , 302) and/or network node (101 , 102) decodes the 20 bits to get the 10 bits representing the decoded concatenated CQI. Then the cells and/or network nodes (301 ,302, 101 , 102) extracts their individual CQIs (CQI1 and CQI2) and uses this information in deciding the modulation information, transport block size, and the number of codes etc. for the next downlink transmission on their respective HSDPA radio link (401 , 402). The information related to modulation and/or transport block size and/or number of codes is sent through individual downlink channels HS-SCCH from each cell. The actual data transmission starts once HS-SCCH is sent (after 2 slots). It shall be noted that a similar operation may be performed on any number of bits representing a CSI. The HARQ-ACK may be represented by one bit and encoded into 10 bits and accordingly the with the description above, two HARQ-ACK (A1 and A2) are represented by one bit each and the concatenation would give two bits which are block encoded into 10 bits to fit the first slot or timeslot in a HS- DPCCH subframe as illustrated in figure 3.

In relation to figures 5, it is mentioned that the CSI may be the bit representation of one or several values representing e.g. a CQI or HARQ-ACK at a certain time instance or during a series of time instances and/or TTIs and/or subframes. The CSI feedback may be e.g. the CSI encoded for HS-DPCCH as described above in relation to figure 5. CSI feedback may be e.g. CQI1 and/or CQI2 encoded into 20 bits to fit in the 2'nd and 3^rd timeslots in an HS-DPCCH subframe. CSI feedback may also be e.g. HARQ-ACK encoded into 10 bits to fit into a 1 ^st time slot on an HS-DPCCH subframe and/or TTI. The HS-DPCCH structure comprises sub-frames (600) which are further divided into 3 slots or time slots (601 , 602, 603). The HARQ-ACK (501 ) for the primary link (401 ) and secondary link (402) is jointly encoded into 10 bits and are transmitted in the first slot of the first HS-DPCCH sub-frame. Similarly the CQI of the primary link (CQI1 ) and CQI of the secondary link (CQI2) are jointly encoded using a (20, 10) block code. The (X,Y) notation shall be interpreted as Y information bits are encoded into X bits to provide error detection and/or error correction.

The joint encoding of CQI1 and CQI2 (into 20 bits) is used to be transmitted in the 2nd and 3rd slots of the HS-DPCCH subframe. The jointly encoded HARQ-ACK (501 ) or CQI (502) may also be called composite CSI feedback or composite feedback as opposed to when only one CQI value (CQ1 , CQI2) or one HARQ- ACK (A1 or A2) value is coded into the subframe individually as is shown in figure 4. The individual CSI feedback may be called non-composite CSI feedback or non- composite feedback or individual feedback (701 , 702) and may contain CQI or HARQ-ACK related to only one of the HSDPA radio links (401 , 402) associated with the serving- or assisting serving HS-DSCH cells (301 , 302) .

Since the wireless device use a common channel for feeding back CSI, the wireless device may be adapted to have a common time reference or known time reference between HS-PDSCH, CPICH, and HS-DPCCH.

In figure 4b there is an illustration of how the sending time instances on the HS- DPCCH may be determined in a wireless device in multiflow operation. The sending time instance may be defined as the time slot or timeslots in a specific HS-DPCCH subframe in which CSI feedback may be transmitted according to the parameters related to CSI feedback (CQI feedback cycle, CQI repetition factor, and HARQ-ACK repetition factor) which are accounted for in relation to figure 6 and figure 6a. These parameters may be called cell specific parameters. In figure 4a there is one cell with one CPICH wherein the CPICH is the pilot channel per cell on which measurements are performed to derive and/or measure and/or estimate the corresponding CQI for the HSDPA radio link in that cell. In the cell, the parameters are CQI feedback cycle (k) = 4, meaning that CQI on the HSDPA radio link in that cell, shall be measured once every four milliseconds (ms) and reported and/or sent thereafter, wherein reporting and or sending may mean providing an encoded representation of the measured or estimated CQI in a HS- DPCC subframe and/or timeslot and/or time slots. The CQI repetition factor

(N_cqi_transmit) = 2 for this cell, which may mean that the measured CQI shall be sent and/or reported two times.

To each sending time instance in the wireless device, there may be a

corresponding receiving time instance in cell. The receiving time instance may be defined as the slots and/or time slots in a certain HS-DPCCH subframe when the cell (301 , 302) and/or network node (101 , 102) receives and/or decodes the CSI feedback on the HS-DPCCH. The absolute difference between the sending time instance and the receiving time instance may relate to the propagation delay and/or frame synchronization between the wireless device and network node and/or HS-DSCH cell.

In addition there may be a configured time instance, which may be defined as the slots or time slots in a specific HS-DPCCH subframe when the HS-DSCH cell expects to receive CSI feedback based on parameters related to CSI feedback. The configuration time instance, in terms of HS-DPCCH subframes and/or time slot or time slots, may be based on the cell specific parameters related to CSI feedback (CQI feedback cycle, CQI repetition factor, and HARQ-ACK repetition factor).

As explained above, at the cell edge of very large cells and/or in some soft handover situations, the HS-DPCCH quality perceived by at the serving- or assisting serving HS-DSCH cell (301 , 302) may not be sufficient to correctly decode the CSI feedback (501 , 502, CQI1 , CQI2, A1 , A2, 701 , 702) on the HS- DPCCH. This means that the CSI feedback may not be received correctly and consequently, due to e.g. incorrectly decoded CQI or HARQ-ACK, the downlink throughput may therefore be significantly reduced.

In figure 6a some parameters or cell specific parameters, are stated. These parameters may be used to adapt to the variations in cell sizes and radio environment conditions. The network (Node B and/or the RNC, 101 , 102, 121 ) may use one or all these control parameters (600) related to channel state information in order to improve the CSI feedback process. This set of parameters (600) may be signaled from and/or via a central network node 121 (RNC), wherein the central network node is directly connected to the network nodes (101 , 102) to the UE (200) via RRC (Radio Resource Control) signaling. The related parameters (600) are described above. Figure 6 illustrates one example where the CQI feedback cycle is 4 ms, the CQI repetition factor is 2 and the HARQ-ACK repetition factor is 3 and how these parameters affect the transmission of CSI feedback on the HS-DPCCH.

If these parameters (600) are set individually per cell, it has been recognized that some CSI feedback , e.g. CQI and/or HARQ-ACK feedback, may be requested from both the HSDPA radio links (401 , 402) in the multiflow operation, in certain HS-DPCCH slots (601 , 602, 603) but only from one of the HSDPA radio links (401 , 402) in another HS-DPCCH subframe or TTI.

This is illustrated in figures 7 and 8. In figure 7, for example, the serving HS-DSCH cell (301 ) is configured with a CQI repetition factor of 2 and the assisting serving HS-DSCH cell (302) with a CQI repetition factor of 1 . For simplicity it is assumed that the HARQ-ACK repetition factor equals 4 for both cells (301 , 302). Then the UE (200) would send CSI feedback related to HARQ-ACK (A/N) in both the cells (301 , 302) four times. It would send composite CSI feedback related to CQI (CQI_C) in one subframe. CQI_C is the composite CQI for the serving- and assisting serving HS-DSCH cells (301 , 302). The next, repeated CQI (CQM ), would relate only to measurements in the serving HS-DSCH cell according to the CQI repetition factor configuration, consequently CQM is an example of non- composite CSI feedback. Another example is illustrated in figure 8, different repetition factors for HARQ- ACK may give rise to a similar situation where the HARQ-ACK feedback relates to both HS-DSCH cells in the multiflow operation in some subframes but only to one of the serving- or assisting serving HS-DSCH cells (301 , 302) in subsequent sub- frames. In figure 9. the serving HS-DSCH cell (301 ) is configured with a HARQ- ACK repetition factor equal to 3 and the HARQ-ACK repetition factor for the assisting serving HS-DSCH cell (302) is equal to 1 (means no repetition). For simplicity it is assumed that the CQI repetition factor is equal to 2 for both cells (301 , 302). In this scenario, the UE (200) would send CSI feedback related to CQI (CQI_C) in both the cells (301 , 302) two times. It would send composite CSI feedback related to HARQ-ACK (A/N_c) in one subframe. A/N_c is the composite HARQ-ACK for the serving- and assisting serving HS-DSCH cells (301 , 302). The next, repeated HARQ-ACKs (A/ISM ), would relate only to the serving HS-DSCH cell according to the HARQ-ACK repetition factor configuration and is another example of non-composite CSI feedback.

In figure 8a, there is an illustration of how the sending time instances may be determined in a wireless device in multiflow operation. The sending time instance may be defined as the time slot or timeslots in which CSI feedback should be transmitted according to the parameters accounted for above in this application. The parameters may be cell specific to determine a different frequency of CSI feedback per cell or HSDPA radio link in multiflow operation. The CSI feedback from a wireless device in multiflow operation may however be fed back on a common feedback channel, e.g. the HS-DPCCH channel as described above in relation to figure 2. In figure 8a there are two different cells with one CPICH in each cell, the serving HS-DSCH cell has CPICH 1 and the assisting serving HS- DSCH cell has CPICH 2. The CPICH is the pilot channel per cell on which measurements are performed to derive the corresponding CQI for the HSDPA radio link in that cell. In figure 8a it is seen that the parameters related to CQI feedback are different for each cell. In the serving HS-DSCH cell with CPICH 1 , the parameters are CQI feedback cycle (k) = 4, meaning that CQI on the HSDPA radio link (401 ) in that cell, shall be measured once every four milliseconds (ms) and reported thereafter. The CQI repetition factor (N_cqi_transmit) = 2 for this cell, which means that the measured CQI shall be encoded to fit into an HS-DPCCH subframe and transmitted in two different subframes. The corresponding values for the assisting serving HS-DSCH cell, with CPICH 2 are CQI feedback cycle (k) = 8, meaning that CQI on the HSDPA radio link (402) in that cell shall be measured once every eight milliseconds (ms). The CQI repetition factor (N_cqi_transmit) = 1 for this cell, which means that the measured SINR shall be estimated and map a bitrepresentation of the CQI value before encoding into an HS-DPCCH subframe. The CSI feedback is only sent once in the assisting serving HS-DSCH cell since the CQI repetition factor is 1 .

If a wireless device (200) is in multiflow operation with one HSDPA radio link in each of these two cells, the sending time instance for CQM (measured CQI for serving HS-DSCH cell with CPICH 1 ) is configured to be in HS-DPCCH subframe 1 , timeslots 2 and 3. A transmission of the same measured value shall, according to the CQI repetition factor, be repeated once in the consecutive subframe on the HS-DPCCH, i.e. in subframe 2 in timeslots 2 and 3. For the assisting serving HS- DSCH cell with CPICH 2, the wireless device determines the sending time instance for CQI_2 (measured CQI for assisting serving HS-DSCH cell with CPICH 2) is configured by the paramters (k, N_cqi_transmit) to be in HS-DPCCH subrame 1 , timeslots 2 and 3. Hereby it is shown how the wireless device can determine that the sending time instances coincide for the serving and assisting serving HS-DSCH cells with CPICH 1 and CPICH 2 in subframe 1 in timeslots 2 and 3. Analogously, the wireless device can determine that the sending time instances for the different cells or HSDPA radio links, do not coincide for subframe 2-4 but that the sending time instances will again coincide in subframe 5. In the same manner, the wireless device can determine whether the sending time instances coincide for other cell specific parameter configurations.

On the network side, the cells, and/or the network nodes providing the cells, can determine whether any CSI feedback, relating to their respective HSDPA radio link, is expected in a certain time instance. On the network side, the HS-DPCCH time slot or time slots when CSI feedback is expected are defined as configured time instance. A cell specific parameter, configuring a time instance, may refer to a configured time instance that may be based on cell specific parameters. Cell specific parameters may be applicable for HSDPA multiflow operation. Cell specific parameters may be applicable per HSDPA radio link and/or per serving- and/or assisting serving HS-DSCH cell meaning that the cell specific parameters may be different for different cells and/or different HSDPA radio links in multiflow operation.

If the cell specific parameters are mutually exchanged between the cells, each cell can be aware of the other cell's configured time instance. In this solution it has been recognized that when the cells (301 , 302) involved in the same mulitflow operation, provide cell specific configuration parameters (600) for CSI feedback, the wireless device can deduce if CSI feedback is requested for both the primary- and the secondary radio links (401 , 402) in the same sub-frame (600), based on the cell specific parameters or cell specific configuration parameters.

If CSI feedback is only requested for one of the radio links (401 , 402), in a certain slot (601 , 602, 603) in a certain subframe (600) (or TTI - transmission Time Interval) it would be possible to transmit e.g. CQI feedback encoded in a non- composite fashion in order to achieve a more robust coding for the CSI feedback (CQI in this example). This will imply that less repetition of e.g. CQI feedback is required in order to maintain the same probability for receiving a correctly decoded CQI in the serving- or assisting serving HS-DSCH cell (301 , 302).

One idea may be to report composite CSI feedback in case the wireless device (200) determines that the sending time instances, for the different HSDPA radio links in a HSDPA multiflow operation, coincide or are the same time slots and/or slots (601 , 602, 603) in the same subframe (600) on the HS-DPCCH

A method is illustrated in figure 9. The method is performed in a wireless device (200), the wireless device (200) being configured with a first- and a second

HSDPA radio link (401 , 402) for HSDPA multiflow operation in a cellular

communications network(100), the method comprises receiving (S1 ) at least a first- and a second cell specific parameter (800). The receiving may consist of receiving, via a receiving module (240), a parameterization (N_cqi_transmit_1 ) of the CQI repetition factor for the first HSDPA radio link (401 ) and another/or same parameterization (N_cqi_transmit_2), of the CQI repetition factor for the second HSDPA radio link (401 ), wherein the first cell specific parameter determines one or several time slots or slots on in a certain HS-DPCCH subframe for sending CSI feedback related to the first HSDPA radio link (401 ) and wherein the second cell specific parameter determines one or several time slots or slots in a certain HS- DPCCH subframe for sending the CSI feedback related to the second HSDPA radio link (402). A sending time instance in the wireless device may be defined as one or several a timeslots on a certain HS-DPCCH subframe when CSI feedback is sent. The first sending time instance is related to the sending time instance for the first HSDPA radio link (401 ) and the second sending time instance is related to the sending time instance for the second HSDPA radio link (402). The sending time instance can be seen as indicating a time slot or slot or time slots or slots in a certain subframe on the HS-DPCCH channel which is the common CSI feedback channel for both the first- and the second HSDPA radio links (401 , 402).

The method further determines (S2), based on the at least first- and second cell specific parameters if the first- and second sending time instances coincide. One illustration of how the determination is performed can be found above in relation to figure 8a. If the first- and second time instances are determined to coincide, the method sends (S3') CSI feedback as a composite feedback, as described in relation to figure 5 whereas if it is determined that the first- and second sending time instances do not coincide the method sends (S3) CSI feedback as non-composite feedback. The non-composite feedback may be seen as CSI feedback related to only one of the first- and second HSDPA radio links. In another example the non-composite feedback may be encoded with an equal amount of bits as the composite feedback. Additionally, or alternatively, the non- composite feedback may be encoded such that the ratio between the number of information bits and the number of encoding bits is lower compared to the encoded composite feedback.

The number of encoding bits is defined as the total number of bits representing the CSI feedback in the HS-DPCCH subframe and/or time slot or slot whereas the number of information bits is the number of bits to represent the value before encoding. E.g. CQI is represented by five bits for a single HSDPA radio link but is encoded with 20 bits on the HS-DPCCH. The number of information bits in this case is 5 whereas the number of encoding bits is 20. In case of HSDPA multiflow operation, the composite CQI consists of 5 + 5 = 10, information bits. Five bits representing CQI for each HSDPA radio link. The number of encoding bits may still be twenty. ^"Therefore the ratio between the number of information bits and number of encoding bits is higher for the composite feedback.

In a further example the HARQ-ACK for a single HSDPA radio link can be represented by one bit (ACK or NACK), i.e one information bit. However, in the HS-DPCCH subframe, it is encoded with 10 bits. In the case of multiflow operation the composite CSI feedback of HARQ-ACK type consists of 1 +1 = 2 information bits but is encoded on the HS-DPCCH with 10 bits.

In one example the non-composite CSI feedback is encoded using a (20,5) and/or a (10, 1 ) block code.

It is also described that the at least first- and second cell specific parameters comprises one of: - CQI feedback cycle (k)

- CQI repetition factor (N_cqi_transmit) - HARQ-ACK repetition factor (N_acknack_transmit)

In one example the first- and second cell specific parameters may be the same, e.g. both being N_cqi_transmit with the same, or different values as described in relation to figure 8a. In a multiflow operation scenario, the first HSDPA radio link may be the primary HSDPA radio link and the second HSDPA radio link may be the secondary

HSDPA radio link.

There is also disclosed a wireless device adapted to being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, the wireless device is further adapted to receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link. The wireless device is further adapted to determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide. Moreover, the wireless device is further adapted to send CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else it is adapted to send CSI feedback as non-composite feedback.

The wireless device may be adapted send non-composite feedback or non- composite CSI feedback , which may be related to only one of the first- and second HSDPA radio links (401 ,402).

It is also disclosed that the wireless device is adapted to encode the CSI feedback to fit in a slot and/or timeslot and subframe on a channel. The channel may be the HS-DPCCH as defined in 3GPP. The wireless device may be adapted to encode the non-composite CSI feedback and the composite CSI feedback with an equal amount of bits.

The wireless device may additionally be adapted to encode the CSI feedback such that the ratio between the number of information bits and the number of encoding bits is lower for the non-composite CSI feedback when compared to the encoded composite CSI feedback . E.g. the wireless may be adapted to encode the non- composite CSI feedback with a (20,5) and/or a (10, 1 ) block code.

The wireless device may additionally be adapted to send CSI feedback comprising CQI and/or HARQ-ACK as defined in 3GPP. Moreover, the wireless device may be adapted to determine if the first- and second sending time instances coincide based on the first- and second cell specific parameters wherein the parameters may comprise one of:

- CQI feedback cycle (k),

- CQI repetition factor (N_cqi_transmit) - HARQ-ACK repetition factor (N_acknack_transm it)

Additionally the first- and second cell specific parameters may or may not be the same and the parameterisation may or may not be the same.

There is also disclosed a method in a network node. The method performed in a first network node, the first network node controls at least one HSDPA radio link in a cellular communications network and the cellular network supporting HSDPA multiflow operation, the method comprises receiving (S1 1 ) CSI feedback at a receiving time instance. As a preferred example, the first network node is the network node controlling the serving- and/or assisting serving HS-DSCH cell that receives CSI feedback related to a first- and or second HSDPA radio link on the common HS-DPCCH in a certain time slot or time slots in a certain HS-DPCCH subframe. The method also comprises decoding (S12) the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter. The decoding (S12) may be based on a first cell specific parameter which may preferably be one or several of

- CQI feedback cycle (k),

- CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit)

These parameters controls in which time slots and subframes on the HS-DPCCH the wireless device shall send CSI feedback to the serving- or assisting serving HS-DSCH cell. With the knowledge of the parameter setting in the cell controlled by the network node it is possible to determine in which subframes and/or timeslot or timeslots the cell, controlled by the network node, expects to receive CSI feedback. These determined subframes and/or timeslot or timeslots correspond to the configured time instance. Thereby, the node may, based on a cell specific parameter, determine (S13) if the receiving time instance coincides with the configured time instance and whether effort should be spent on decoding the received CSI feedback . If the configured time instance and the receiving time instance do not coincide the CSI feedback is considered to be CSI feedback for the other cell in the HSDPA multiflow operation scenario and consequently this CSI feedback is not interesting for this cell. However, in case the configured time instance and the receiving time instance coincide, the network node controlling the cell must determine if the received CSI feedback is composite or non-composite in order to decode the CSI feedback. Disclosed herein are two alternative methods for determining whether the CSI feedback is information is composite or non-composite. A first alternative method may be briefly described as to blindly decode and test the output against an expected value. If the test is OK it implies that the decoding was correct else the method propose to use another decoder.

E.g. the method may comprise a determining based on blind decoding of the CSI feedback, wherein the blind decoding is performed by applying a first- and/or a second decoding method. Additionally, the first decoding method may be associated with the non-composite CSI feedback and the second decoding method may be associated with the composite CSI feedback.

Additionally and/or alternatively the decoded CSI feedback is tested against a condition, wherein the condition may be to check if the decoded CSI feedback is:

- within- or outside an expected range

- greater than, equal to or less than, an expected value

A range may be e.g. a weighted average of e.g. the latest received CQI values with a confidence interval wherein the range may be set out by the values representing the limits for the confidence interval.

The range or values that may be used for a test to determine if the blind decoding was performed with a correct decoder, may also be obtained by some statistical prediction algorithm which is based on a sequence of previously decoded CSI feedback values. If in the method, the decoded CSI feedback is determined to assume a value outside the expected range of a test and/or below/under a target value, the decoding is repeated with another decoding method, e.g. as exemplified above. In a more specific example if the decoded CSI feedback is blindly decoded, using the first decoding method associated with the non-composite decoding, and the obtained value does not fall within the expected range of valid values, the blind decoding is repeated with the second decoding method, associated with composite CSI feedback to obtain the decoded CSI feedback value (i.e. CQI: Ό- 31 ' or HARQ-ACK: Ό' or ).

Another option to determine if the CSI feedback is composite or non-composite may be to determine, based on first- and/or second cell specific parameters, in which HS-DPCCH subframes and/or timeslot or timeslots, the wireless device will send CSI feedback compositely- or non-compositely encoded.

In this example it is assumed that the network node controlling the cell has obtained the values for the cell specific parameters related to CSI feedback (CQI feedback cycle [k], CQI repetition factor [N_cqi_transmit] and/or HARQ-ACK repetition factor [N_acknack_transmit]), valid for the other cell involved in the HSDPA multiflow operation. This can be achieved via signalling (e.g. RRC signalling) from the wireless device to the first network node and/or signalling from another NodeB which may be serving the other cell in the HSDPA multiflow operation and/or from or via an RNC connected to the network nodes (NodeB's) involved in the HSDPA multiflow operation. If these cell specific parameters are known in the cell controlled by the first network node, it is possible to determine the configured time instances in both the serving- and the assisting serving HS- DSCH cells and thus it is possible to determine whether the wireless device has sent composite or non-composite CSI feedback in certain HS-DPCCH subframes and/or timeslot or timeslots.

Consequently the determining (S13) may be based on at least on of:

- the first configured time instance

- a second configured time instance being based on a second cell specific

parameter The second configured time instance may be defined as the time instance when the other cell in the multiflow operation, expects to receive CSI feedback and the second cell specific parameter is received from the other cell as described above.

The method may also comprise a step of determining that CSI feedback is non- composite feedback, if the second configured time instance does not coincide with the first configured time instance.

Additionally and/or alternatively the method may also comprise receiving the first- and second cell specific parameters from, or via, at least one of:

- a second network node (RNC) - the first network node in case of intra nodeB HSDPA multiflow

- the wireless device

In this method, the first- and second cell specific parameters may comprise one of:

- CQI feedback cycle (k)

There is also disclosed a first network node (NB), which is configured to control at least one HSDPA radio link in a cellular communications network and the cellular network supports HSDPA multiflow operation, the network node is further configured to and/or adapted to receive CSI feedback at a receiving time instance. The network node is further adapted to decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter. The benefit of this is to not waste effort on decoding CSI feedback which is not requested by the cell, which is controlled by the first network node. The first network node is also adapted to determine whether the received CSI feedback is composite or non-composite in order to enable proper decoding of the received CSI feedback.

The first network node may be adapted to determine whether the received CSI feedback is composite or non-composite, based on blind decoding of the CSI feedback. The network node may additionally be adapted perform the blind decoding by applying a first- and/or a second decoding method wherein the first decoding method is associated with the non-composite feedback and the second decoding method is associated with the composite feedback

E.g. the the network node may be configured to determine whether the received CSI feedback is composite or non-composite based on blind decoding of the CSI feedback , wherein network node is adapted to perform blind decoding by applying a first- and/or a second decoding method, wherein the first decoding method may be associated with the non-composite CSI feedback and the second decoding method may be associated with composite CSI feedback . Additionally and/or alternatively the network node may be adapted to test whether the decoded CSI feedback fulfils a condition, wherein the condition may be to check if the decoded CSI feedback is:

- within- or outside an expected range

- greater than, equal to or less than, an expected value The network node is further adapted to determine that the decoded CSI feedback fulfils the condition if the decoded value is within or outside a range and/or the decoded value is above or below an expected value.

The network node may additionally be configured to repeat the decoding if it is determined that the decoded CSI feedback does not fulfil a condition. Examples of obtained values from decoding CSI feedback may be [0, 31 ] for CQI and [0, 1 ] for HARQ-ACK (i.e. CQI: O-31 ' or HARQ-ACK: Ό' or ).

The network node may additionally be configured to determine if the CSI feedback is composite or non-composite is to determine, based on first- and/or second cell specific parameters. If the network node is involved in HSDPA multiflow operation with another network node and the first network node has knowledge about the cell specific parameters used to configure the CSI feedback in the other cell involved in HSDPA multiflow operation, it is possible to determine in which HS- DPCCH subframes and timeslots, the wireless device will send CSI feedback compositely or non-compositely encoded. Analogously, the first network node may determine in which HS-DPCCH subframes and timeslot or time slots composite CSI feedback is expected.

In one example the first network node is configured to receive the cell specific parameters related to CSI feedback (CQI feedback cycle [k], CQI repetition factor [N_cqi_transmit] and/or HARQ-ACK repetition factor [N_acknack_transmit]), related to the other cell involved in the HSDPA multiflow operation. This can be achieved via signalling (e.g. RRC signalling) from the wireless device to the first network node and/or signalling from the other network node that is controlling the other cell in the HSDPA multiflow operation. The first network node can also be configured to receive the parameters from or via an RNC connected to the network nodes (NodeB's) involved in the HSDPA multiflow operation. If these cell specific parameters are known in the cell controlled by the first network node, it is possible to determine the configured time instances in both the serving- and the assisting serving HS-DSCH cells and thus it is possible to determine whether the wireless device has sent composite or non-composite CSI feedback in certain HS-DPCCH subframes and/or timeslot or timeslots.

Consequently the first network node may be adapted and/or configured to determine if CSI feedback is composite or non-composite based on at least on of: - the first configured time instance

- a second configured time instance being based on a second cell specific

parameter

The second configured time instance may be defined as the time instance when the other cell in the multiflow operation, expects to receive CSI feedback and the second cell specific parameter is received from the other cell as described above.

The first network node may also be configured and/or adapted to determine that CSI feedback is non-composite feedback, if the second configured time instance does not coincide with the first configured time instance. Additionally and/or alternatively the first network node may be also adapted to receive the first- and second cell specific parameters from, or via, at least one of:

- a second network node (RNC)

- the first network node in case of intra nodeB HSDPA multiflow

- the wireless device The first- and second cell specific parameters, which the first network node is adapted to obtain and/or receive, may comprise one of:

- CQI feedback cycle (k)

- CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit) There is also disclosed a first computer program (225, 235) comprising instructions, which when executed on a processing circuitry (210) cause the processing circuitry (210) to carry out and/or control the methods in the wireless device (200) as described herein. A second computer program is also disclosed. The second computer program comprises instructions, which when executed on a processing circuitry (1 10) cause the processing circuitry (1 10) to carry out and/or control the methods in the network node (101 , 102, 121 ) as described herein. There is also disclosed a first carrier (230) containing the first computer program wherein the carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium.

There is also disclosed a second carrier containing the second computer program wherein the carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium.

A wireless device (200) is disclosed wherein the wireless device (200) is adapted to being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, wherein the wireless device (200) comprises a receiving module(240), adapted to receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link. The wireless device (200) further comprises a determining module (250), adapted to determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide. The wireless device (200) also comprises a sending module (260), adapted to send CSI feedback encoded as composite feedback if it is determined that the first- and second sending time instances coincide, else it is adapted to send CSI feedback encoded as non-composite feedback.

A network node (101 , 102, 121 ) is disclosed. The network node comprises a controlling module (170), adapted to control at least one HSDPA radio link (401 , 402) in a cellular communications network and the cellular network supports HSDPA multiflow operation and the network node further comprises a receiving module (140), adapted to receive CSI feedback at a receiving time instance. The network node additionally comprises a decoding module (150), adapted to, decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter. Further, the network node comprises a determining module, adapted to determine whether the received CSI feedback is composite or non- composite. FIG. 14 is a schematic diagram illustrating an example of a wireless device.

In this particular example, at least some of the steps, functions, procedures, modules and/or blocks described herein are implemented in a computer program 225; 235, which is loaded into the memory 220 for execution by processing circuitry including one or more processors 210. The processor(s) 210 and memory 220 are interconnected to each other to enable normal software execution. An optional input/output device may also be interconnected to the processor(s) and/or the memory to enable input and/or output of relevant data such as input parameter(s) and/or resulting output parameter(s). The term 'processor' should be interpreted in a general sense as any system or device capable of executing program code or computer program instructions to perform a particular processing, determining or computing task.

The processing circuitry including one or more processors is thus configured to perform, when executing the computer program, well-defined processing tasks such as those described herein.

The processing circuitry does not have to be dedicated to only execute the above- described steps, functions, procedure and/or blocks, but may also execute other tasks. According to another example, there is provided a computer program 225; 235 comprising instructions, which when executed by at least one processor 210, cause the at least one processor 210 to:

- receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending

CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link;

- determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide; and

- send CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else send CSI feedback as non-composite feedback

In yet another example, the proposed technology also provides a carrier 220; 230 comprising the computer program 225; 235, wherein the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

FIG. 15 is a schematic diagram illustrating an example of a network node. In this particular example, at least some of the steps, functions, procedures, modules and/or blocks described herein are implemented in a computer program 125; 135, which is loaded into the memory 120 for execution by processing circuitry including one or more processors 1 10. The processor(s) 1 10 and memory 120 are interconnected to each other to enable normal software execution. An optional input/output device may also be interconnected to the processor(s) and/or the memory to enable input and/or output of relevant data such as input parameter(s) and/or resulting output parameter(s).

The term 'processor' should be interpreted in a general sense as any system or device capable of executing program code or computer program instructions to perform a particular processing, determining or computing task.

The processing circuitry including one or more processors is thus configured to perform, when executing the computer program, well-defined processing tasks such as those described herein. The processing circuitry does not have to be dedicated to only execute the above- described steps, functions, procedure and/or blocks, but may also execute other tasks.

According to another example, there is provided a computer program 125; 135 comprising instructions, which when executed by at least one processor 1 10, cause the at least one processor 1 10 to:

- receive CSI feedback at a receiving time instance;

- decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter; and - determine whether the received CSI feedback is composite or non- composite

In yet another example, the proposed technology also provides a carrier 120; 130 comprising the computer program 125; 135, wherein the carrier is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium. By way of example, the software or computer program 125; 135; 225; 235 may be realized as a computer program product, which is normally carried or stored on a computer-readable medium 120; 130; 220; 230, in particular a non-volatile medium. The computer-readable medium may include one or more removable or non- removable memory devices including, but not limited to a Read-Only Memory

(ROM), a Random Access Memory (RAM), a Compact Disc (CD), a Digital Versatile Disc (DVD), a Blu-ray disc, a Universal Serial Bus (USB) memory, a Hard Disk Drive (HDD) storage device, a flash memory, a magnetic tape, or any other conventional memory device. The computer program may thus be loaded into the operating memory of a computer or equivalent processing device for execution by the processing circuitry thereof.

The flow diagram or diagrams presented herein may also be regarded as a computer flow diagram or diagrams, when performed by one or more processors. A corresponding communication station may therefore be defined as a group of function modules, where each step performed by the processor corresponds to a function module. In this case, the function modules are implemented as a computer program running on the processor. Hence, the communication station may alternatively be defined as a group of function modules, where the function modules are implemented as a computer program running on at least one processor.

The computer program residing in memory may thus be organized as appropriate function modules configured to perform, when executed by the processor, at least part of the steps and/or tasks described herein. Figure 16 is a schematic block diagram illustrating an example of a wireless device comprising a group of function modules.

As one example there is provided a wireless device 200, which comprises a receiving module 240, a determining module 240 and a sending module 260. The receiving module 240 is adapted for receiving at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link..

The determining module 240 is adapted for determining, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide. The sending module 260 is adapted for sending CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else it is adapted for sending CSI feedback as non-composite feedback

Figure 17 is a schematic block diagram illustrating an example of a network node comprising a group of function modules. As one example there is provided a network node 101 ; 102, which comprises a receiving module 140, a decoding module 150 and a determining module 160.

The receiving module 140 is adapted for receiving CSI feedback at a receiving time instance.

The decoding module 150 is adapted for decoding the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter.

The determining module 160 is adapted for determining whether the received CSI feedback is composite or non-composite

The embodiments described above are merely given as examples, and it should be understood that the proposed technology is not limited thereto. It will be understood by those skilled in the art that various modifications, combinations and changes may be made to the embodiments without departing from the present scope as defined by the appended claims. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible.

In order to increase the cell edge throughput in HSDPA, Multipoint transmission (MP-HSDPA) or HSDPA multiflow operation, was standardized in 3GPP Release 1 1 . In MP-HSDPA, data streams from two different sectors belonging to the same Node B or different Node Bs are transmitted simultaneously to the UE. The data streams may be e.g. HSDPA radio links. When the two sectors belongs to the same Node B, it is called Intra Node-B aggregation and when the two sectors belong to different Node Bs, then it is called Inter Node-B aggregation. The advantage of MP-HSDPA stems from the fact that the data streams can be thought of as a network MIMO where the spatial antennas of MIMO are separated. The MP-HSDPA may also be referred to as HSDPA multiflow or just multi flow (MF) and can be classified in two categories:

1 . Intra Node B multi flow

2. Inter Node B multi flow 1 . Intra Node B multi flow: Intra Node B multi flow is performed over two cells belonging to the same Node-B operating on the same frequency as shown in Figure 1 1. In this scheme two independent transport blocks are scheduled to an UE simultaneously. The gains associated with this scheme can be thought of as spatial resource pooling and it is mainly useful for increasing downlink throughput for UEs in the softer handover region. Another advantage of Intra Node B multi flow is that this scheme is fairly simple and since there only is one RLC flow and the data split can be performed at the MAC layer (as for 3GPP REL-8 multi-carrier operation). 2. Inter Node B multi flow: In Inter Node B multi flow, the aggregation occurs across two cells belonging to different Node-Bs as shown in figure 12. In this scheme, transmissions to a single UE occur simultaneously from these two cells on the same frequency. Similar to the intra Node B multi flow, the gains associated with this scheme can be thought of as spatial resource pooling and is useful for increasing the downlink performance for UEs in soft handover.

In general the initiation of HSDPA multiflow to a particular UE is as shown in the message sequence chart in figure 13. The UE measures the SINR between two Node B's and sends the handover message 1 A to the Network (RNC via Node B). The RNC evaluates the conditions for HSDPA mutliflow operation. If the network decides to use HSDPA mutliflow operation for this particular UE, it initiates the HSDPA mutliflow operation using RRC ASU. After receiving the ASU complete message from UE, network starts the HS-DSCH transmissions from two Node Bs or network nodes. Channel Quality reporting in HSDPA mutliflow operation

Figure 2 shows the message sequence chart for data transmission in HSDPA mutliflow operation a multipoint communication system. Note that P-Node B indicates the primary Node B or first network node and/or serving cell and the S- Node B indicates secondary Node B or second network node and/or the assisted Node B. The pilot channel CPICH (P-CPICH) may be sent from each Node B and/or cell. Note that the signals sent on the pilot channel may be called pilot signals. The pilot signals may differ by different scrambling codes. From the individual pilot signals, the wireless device estimates the SINR. The estimated SINR is mapped onto a suitable CQI representing the channel quality information. The CQI may be encoded into 20 bits and fit into an HS-DPCCH subframe and/or TTI and time slot or slot. The encoded CQI may be called CQI feedback or more generally, CSI feedback. The CSI feedback may be sent through a common feedback channel HS-DPCCH. The same HS-DPCCH is sent over the two HSDPA radio links. The HS-DPCCH structure is shown in Figure 3.

The feedback signaling may comprise Hybrid-ARQ Acknowledgement (HARQ- ACK) and Channel-Quality Indication (CQI) for each link transmitted in the same subframe. Each sub frame of length 2 ms (3^*2560 chips), each subframe may comprise 3 slots or timeslots, each of length 2560 chips. The HARQ-ACK for the primary link and secondary link is jointly encoded into 10 bits and are transmitted in the first slot of the first HS-DPCCH sub-frame. Similarly the CQI of the primary link (CQI1 ) and CQI of the secondary link (CQI2) are jointly encoded using a (20, 10) block code and these 20 bits are transmitted in the 2^nd and 3^rd slots. The joint encoding operation of CQI1 and CQI2 is shown in Figure 5, where the 5 bits of individual CQI of the primary cell is concatenated with the 5 bits of CQI of the secondary link. Then these 10 bits are passed through the block encoder to form the 20 coded bits. Once each Node B receives the composite CQI information, each Node B scheduler may decode the 10 bits and extract their individual CQI values and may use this information in deciding the modulation information, transport block size, and the number of codes etc. for the next downlink transmission. This information is sent through individual downlink channels HS-SCCH from each node. The actual data transmission starts once HS-SCCH is sent (after 2 slots).

Parameters Related to the Channel Quality and HARQ-ACK Reporting

The network (Node B and the RNC) controls parameters related to channel state information or CSI feedback. The network may be a first network node. The parameters controlled by the network are called cell specific parameters and may be signaled by the serving RNC and/or the first network node to the wireless device, and/or UE, via RRC. The set of parameters may comprise: • CQI feedback cycle: This parameter describes how frequently the UE shall transmit a new CQI report. The parameter is configurable via the radio resource control (RRC) protocol by the serving RNC (S-RNC) and the supported values are {0, 2, 4, 8, 10, 20, 40, 80, 160}ms. The signaled value 0 ms is used to indicate that the UE should not transmit any CQI reports.

• CQI repetition factor (N cqi transmit) This parameter describes the number of times a certain CQI report should be transmitted. The CQI information is repeated a total of N_cqi_transmit-1 times and the set of values that can be configured via RRC by the S-RNC are {1 ,2,3,4}. · HARQ-ACK repetition factor (N acknack transmit) This parameter describes how many times the UE should transmit the (same) HARQ-ACK message associated with a transport block. In other words, the HARQ-ACK transmission is repeated a total of N_acknack_transmit-1 times. The supported values are {1 ,2,3,4} and it is configured by the S-RNC via RRC.

Figure 6 illustrates one example where the CQI feedback cycle is 4 ms, the CQI repetition factor is 2 and the HARQ-ACK repetition factor is 3.

The current standard allows a single repetition factors for all cells. However, since the wireless device, or UE, may be served from two different network nodes and/or Node Bs (two different locations) in HSDPA multiflow operation, it may not be beneficial to configure the same repetition factor for bothe cells and/or HSDPA radio links, in terms of uplink throughput. Hence it is

recommended to use two different repetition factors for each network node and/or cell and/or HSDPA radio link . However, the standard does not define the HS-DPCCH structure when the RNC configures two different repetition factors.

In this his solution a method to transmit the channel state information feedback is disclosed for the case when the cells, in HSDPA multiflow operation with a wireless device, and the cells and/or HSDPA radio links and/or network nodes are configured with different CSI repetition factors.

The reliability of channel state information may be increased due to an increase in Hamming distance of CQI, which may imply that the wireless device, or UE, transmits control channel information with less power, while allocating more power for the data traffic channels. Hence the own user throughput may be increased while less interference is created to the other users in the cell. This may improve the system throughput.

To report the composite CQI during the TTIs when the two repetition factors corresponding to CQI repetition, points out time slots and/or subframes on HS- DPCCH for transmission of CSI feedback for the different cells and/or HSDPA radion links and/or different network nodes, coincide, and report non-composite CSI feedback when they don't coincide. This will be explained through an example. For example, let's say the RNC configures the serving Node B with CQI repetition factor of 2 and assisting Node B with CQI repetition factor of 1 . For simplicity let's assume the HARQ-ACK repetition factor equal to 4 for both the cells. Then the UE send, in HS-DPCCH as shown in figure 7, in the first TTI, the composite CQI (CQI_C), which is transmitted using (20, 10) block code, while in the next TTI since the repetition factor of the primary cell is '2', while the repetition factor of secondary cell is (means no repetition), only the CQI of the primary cell coded using (20,5) block code is transmitted. The advantage of this method is that during these intervals where only one CQI is transmitted using 20 bits, the detection performance is improved. This is because the performance of block code (probability of block error) is proportional to the Q-function.

Ρβ OC £>( 'd min SNR) ₍eq. 1 ) Where Pe is the probability of bit error and Q is the Q function which is strictly decreasing with higher arguments. SNR is the operation signal to noise ratio, and dmin is the minimum Hamming distance of the block code (n, k), which is given by: d mm = Π— k + 1 (eq. 2) Note: 'k' in context of coding is different from 'k' in the context of configuring CSI feedback where 'k' represents CQI reporting cycle

Where n is the number of coded bits, k is the number of input bits. Hence for example for (20, 10) block code, the minimum Hamming distance d_min is 20-10+1 = 11 , while for (20, 5) block code d_min is 20-5+1 = 16. Hence the probability of error of (20, 5) is superior to that of (20, 10) block code.

Hence during those periods when only one CQI is transmitted the performance is improved significantly.

Similar to two types of CQI reporting, two types of HARQ-ACK reporting can be envisioned if the RNC configures two different repetition factors for the two cells in HSDPA multiflow operation with a wireless device. Figure 8 shows an example when the HARQ-ACK repetition factor for the primary cell is equal to 3 and the HARQ-ACK repetition factor for the secondary cell is equal to 1 (means no repetition), and for simplicity let's assume the CQI repetition factor equal to 2 for both cells. It can be seen from figure 8 that during the first TTI, the UE uses joint ACK-NAK code word and while during the next TTI's the UE uses ACK-NAK code word corresponding to the first cell. Similar to the case of two different repetition factors of CQI, in this case also the hamming distance is improved there by improving the detection performance. When the UE is multipoint/CoMP operation it identifies if the RNC or highler layers configures two sets of repetition factors, then it reports the composite CQI during the TTIs or subframes or slots or time slots when the two repetition factors corresponding to CQI repetition, coincide, and report individual CQIs when they don't coincide. And for HARQ-ACK operation, it reports joint HARQ-ACK during the TTIs or subframes or slots or time slots when the two repetition factors corresponding to HARQ-ACK coincide, and report individual HARQ-ACK when they don't coincide.

(N_cqi_transmit) and/or HARQ-ACK repetition factor (N_acknack_transmit) as they are specified in 3GPP spec TS25.331 v1 1 .2.0. These parameters may in this disclosure be a first- and a second cell specific parameter. The cell specific parameters may be used to configure a sending time instance. Configuring a sending time instance in a wireless device may be defined as the wireless device determining one or several subframes and/or timeslots and/or slots on the HS- DPCCH based on one or several cell specific parameter. Configuring of a sending time instance may be done per HSDPA radio link.

CSI feedback may be defined as CQI and/or HARQ-ACK. CSI feedback may also be defined as the bit representation of the CQI and/or HARQ-ACK of a value represent CSI feedback may be CQI (Channel Quality Indication) and/or HARQ-ACK (Hybrid ARQ ACK).

A user equipment (UE) may generally be a device configured for wireless device- to-device communication (it may be a D2D device) and/or a terminal for a wireless and/or cellular network, in particular a mobile terminal, for example a mobile phone, smart phone, tablet, PDA, etc. The term "wireless device" is used interchangeably with the term "UE" or "user equipment" throughout this disclosure. A user equipment may be a node of or for a wireless communication network as described herein. It may be envisioned that a user equipment is adapted for one or more RATs, in particular UTRAN or WCDMA UTRA. Radio circuitry may comprise for example a receiver device and/or transmitter device and/or transceiver device. Control circuitry may include a controller, which may comprise a microprocessor and/or microcontroller and/or FPGA (Field-Programmable Gate Array) device and/or ASIC (Application Specific Integrated Circuit) device. It may be considered that control circuitry comprises or may be connected or connectable to memory, which may be adapted to be accessible for reading and/or writing by the controller and/or control circuitry. A node or device of or for a wireless communication network, in particular a node or device for device-to-device communication, may generally be a user equipment or D2D device. It may be considered that a user equipment is configured to be a user equipment adapted for WCDMA UTRAN.

A storage medium may be adapted to store data and/or store instructions executable by control circuitry and/or a computing device, the instruction causing the control circuitry and/or computing device to carry out and/or control any one of the methods described herein when executed by the control circuitry and/or computing device. A storage medium may generally be computer-readable, e.g. an optical disc and/or magnetic memory and/or a volatile or non-volatile memory and/or flash memory and/or RAM and/or ROM and/or EPROM and/or EEPROM and/or buffer memory and/or cache memory and/or a database. Radio spectrum: Although at least some of the embodiments may be described for D2D transmissions in the UL spectrum (FDD) or UL resources (TDD), the embodiments are not limited to the usage of UL radio resources, neither to licensed or unlicensed spectrum, or any specific spectrum at all.

A cellular network or mobile or wireless communication network may comprise e.g. an LTE network (FDD or TDD), UTRA network, CDMA network, WiMAX, GSM network, any network employing any one or more radio access technologies (RATs) for cellular operation. The description herein is given for LTE, but it is not limited to the LTE RAT.

RAT (radio access technology) may generally include: e.g. LTE FDD, LTE TDD, GSM, CDMA, WCDMA, WiFi, WLAN, WiMAX, etc.

A network node may be a radio network node (which may be adapted for wireless or radio communication, e.g. with a D2D device or a UE) or another network node. A network node generally may be a controlling node. Some examples of a radio network node or controlling node are a radio base station, in particular an eNodeB or a NodeB, a relay node, an access point, a cluster head, RNC, etc. The radio network node may be comprised in a mobile communication network and may support and/or be adapted for cellular operation or communication and/or D2D operation or communication. A network node, in particular a radio network node, may comprise radio circuitry and/or control circuitry, in particular for wireless communication. Some examples of a network node, which is not a radio network node, may comprise: a core network node, MME, a node controlling at least in part mobility of a wireless device, SON node, O&M node, positioning node, a server, an application server, a D2D server (which may be capable of some but not all D2D-related features), a node comprising a ProSe function, a ProSe server, an external node, or a node comprised in another network. Any network node may comprise control circuitry and/or a memory. A network node may be considered to be serving a D2D device or UE, if it provides a cell of a cellular network to the served node or D2D device or UE and/or is connected or connectable to the D2D device or UE via and/or for transmission and/or reception and/or UL and/or DL data exchange or transmission and/or if the network node is adapted to provide the D2D device or UE with allocation and/or configuration data and/or a measurement performance characteristic and/or to configure the D2D device or UE.

It shall be noted that a cell specific parameter may also be called a UE specific parameter. The UE specific parameter may, in this case, mean that different wireless devices may be configured with different parameter values even if the wireless devices are connected to the same cell.

CSI feedback may be sent from the wireless device to the network and/or network node. In HSDPA multiflow operation the CSI feedback is sent as encoded values representing the CSI. E.g. CSI feedback in case of CSI being CQI may be sent

HSDPA multiflow operation involves a serving HS-DSCH cell (primary cell), which is the cell associated with the UTRAN access point, or Node B, performing transmission and reception of the serving HS-DSCH radio link (primary link) for a given UE. The serving HS-DSCH cell is always part of the current active set of the UE.

HSDPA multiflow operation also involves an assisting serving HS-DSCH Cell (secondary cell), which in addition to the serving HS-DSCH cell, is a cell in the same frequency, where the UE is configured to simultaneously monitor a HS- SCCH set and receive HS-DSCH if it is scheduled in that cell. The assisting serving cell is associated with a UTRAN access point, or Node B, performing transmission and reception of the assisting serving HS-DSCH radio link for a given UE. The node B, which controls the primary cell may be called primary node B (P- NodeB). The node B, which controls the secondary cell may be called secondary node B (S-NodeB). In case the primary node B is the same as the secondary nodeB it is called an intra-NodeB HSDPA multiflow operation. If the primary- and secondary nodeBs are different, it is called an inter NodeB HSDPA multiflow operation.

A cell may be "involved" in HSDPA multiflow operation if it is one of the serving- or assisting serving HS-DSCH cells in the connection with the wireless device. It can also be phrased as if the cells are associated with the HSDPA radio links related to the HSDPA multiflow operation with the wireless device.

Configuring a time instance is defined by assigning a parameter value to the parameters related to CSI feedback that determines in which subframes and/or timeslots on the HS-DPCCH, a certain CSI feedback may be sent by the wireless device or expected by the network nodes. Composite feedback or composite CSI feedback may be defined as CSI feedback valid for both HSDPA radio links in HSDPA multiflow operation.

HSDPA multiflow operation may be defined as the network having set up two HSDPA radio links on the same frequency towards the same wireless device.

Briefly described, a solution is provided to improve the CSI feedback reporting in cellular communications network configured for multiflow operation. As explained above, with shorter reporting periods or more frequent repetition of CSI feedback, more UL signaling on e.g. HS-DPCCH from the wireless device, is required, which in turn can cause a reduced system throughput for uplink, i.e. uplink capacity.

In a scenario with multipoint transmission the wireless device is supposed to send a composite CSI feedback on the HS-DPCCH. A composite CSI feedback in the context of CSI feedback, in general means that more feedback information has to fit into an already defined feedback format which in turn means that feedback is less redundant or less protected compared to when the CSI feedback is not composite

In this solution it has been recognized that when the cells involved in the same mulitflow operation provide different configuration parameters related to CSI feedback, the wireless device can deduce if CSI feedback is requested for both the primary- and the secondary radio links in the same sub-frame. If CSI feedback is only requested for one of the radio links it is possible to transmit e.g. CQI feedback coded by using a (20,5) code instead of a (20, 10) code in order to achieve a more robust coding for the CSI (CQI in this example). This will imply that less repetition of e.g. CQI feedback is required in order to maintain the same probability for receiving a correct CQI.

A wireless communication system is, in this disclosure, used interchangeably with wireless communication network. A wireless communication system may provide wireless communication. In the context of this description, wireless communication may be communication, in particular transmission and/or reception of data, via electromagnetic waves and/or an air interface, in particular radio waves, e.g. in a wireless communication network and/or utilizing a radio access technology (RAT). The communication may be between nodes of a wireless communication network and/or in a wireless communication network. A communication may generally involve transmitting and/or receiving messages, in particular in the form of packet data. A message or packet may comprise control and/or configuration data and/or payload data and/or represent and/or comprise a batch of physical layer transmissions. Control and/or configuration data may refer to data pertaining to the process of communication and/or nodes of the communication. It may, e.g., include address data referring to a node of the communication and/or data pertaining to the transmission mode and/or spectral configuration and/or frequency and/or coding and/or timing and/or bandwidth as data pertaining to the process of communication or transmission, e.g. in a header. Each node involved in such communication may comprise radio circuitry and/or control circuitry and/or antenna circuitry, which may be arranged to utilize and/or implement one or more than one radio access technologies. Radio circuitry of a node may generally be adapted for the transmission and/or reception of radio waves, and in particular may comprise a corresponding transmitter and/or receiver and/or transceiver, which may be connected or connectable to antenna circuitry and/or control circuitry. Control circuitry of a node may comprise a controller and/or memory arranged to be accessible for the controller for read and/or write access. The controller may be arranged to control the communication and/or the radio circuitry and/or provide additional services. Circuitry of a node, in particular control circuitry, e.g. a controller, may be programmed to provide the functionality described herein. A corresponding program code may be stored in an associated memory and/or storage medium and/or be hardwired and/or provided as firmware and/or software and/or in hardware. A controller may generally comprise a processor and/or microprocessor and/or microcontroller and/or FPGA (Field-Programmable Gate Array) device and/or ASIC (Application Specific Integrated Circuit) device. More specifically, it may be considered that control circuitry comprises and/or may be connected or connectable to memory, which may be adapted to be accessible for reading and/or writing by the controller and/or control circuitry. Radio access technology may generally comprise, e.g., Bluetooth and/or Wifi and/or Wl MAX and/or cdma2000 and/or GERAN and/or GSM and/or UTRAN and/or WCDMA and/or in particular E-Utran and/or LTE. A communication may in particular comprise a physical layer (PHY) transmission and/or reception, onto which logical channels and/or logical transmission and/or receptions may be imprinted or layered. A node of a wireless communication network may be implemented as a D2D device and/or user equipment and/or base station and/or relay node and/or any device generally adapted for device-to-device communication. A wireless communication network may comprise at least one of a device configured for device-to-device communication, a D2D device, and/or a user equipment and/or base station and/or relay node, in particular at least one user equipment, which may be arranged for device-to-device communication with a second D2D device or node of the wireless communication network, in particular with a second user equipment. A node of or for a wireless communication network may generally be wireless device configured for wireless device-to-device communication, in particular using the frequency spectrum of a cellular and/or wireless

communications network, and/or frequency and/or time resources of such a network

Claims

1 . A method, performed in a wireless device, the wireless device being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular communications network, wherein the method comprises: - receiving at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending CSI feedback related to the second HSDPA radio link - determining, based on the first- and second cell specific parameters, if the first- and second sending time instances coincide

- sending CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else

- sending CSI feedback as non-composite feedback

2. A method according to claim 1 , wherein the non-composite feedback is related to only one of the first- and the second HSDPA radio links.

3. A method according to any of claims 1 -2, wherein the non-composite feedback is encoded with an equal amount of bits as the composite feedback.

4. A method according any of claims 1 -3, wherein the non-composite CSI feedback is encoded such that the ratio between the number of information bits and the number of encoding bits is lower compared to the encoded composite feedback.

5. A method according to any of claims 1 -4, wherein the non-composite CSI feedback is encoded using a (20,5) block code and/or a (10, 1 ) block code.

6. A method according to any of the previous claims, wherein the CSI feedback comprises CQI and/or HARQ-ACK.

7. A method according to any of the previous claims, wherein the at least first- and second cell specific parameters comprises one of: - CQI feedback cycle (k)

- CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit)

8. A method according to any one of the previous claims, wherein the composite feedback is related to the first- and the second HSDPA radio links.

9. A wireless device adapted to being configured with a first- and a second

HSDPA radio link for HSDPA multiflow operation in a cellular communications network, the wireless device is further adapted to:

- determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide - send CSI feedback as a composite feedback, if it is determined that the first- and second sending time instances coincide, else

- send CSI feedback as non-composite feedback

10. A wireless device according to claim 9, wherein the non-composite CSI feedback is related to only one of the first- and the second HSDPA radio links.

1 1 . A wireless device according to any of claims 9-10, wherein the non- composite CSI feedback is encoded with an equal amount of bits as the composite CSI feedback .

12. A wireless device according to any of claims 9-1 1 , wherein the non- composite CSI feedback is encoded such that the ratio between the number of information bits and the number of encoding bits is lower compared to the encoded composite feedback.

13. A wireless device according to any of claims 9-12, wherein the non- composite CSI feedback is encoded using a (20,5) block code and/or a (10, 1 ) block code.

14. A wireless device according to any of claims 9-13, wherein the CSI feedback comprises CQI and/or HARQ-ACK.

15. A wireless device according to any of claims 9-14, wherein the at least first- and second cell specific parameters comprises one of:

- CQI feedback cycle (k)

- CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit)

16. A method performed in a first network node, the first network node controlling at least one HSDPA radio link in a cellular communications network and the cellular network supporting HSDPA multiflow operation, the method comprises:

- receiving (S1 1 ) CSI feedback at a receiving time instance - decoding (S12) the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter

- determining (S13), whether the received CSI feedback is composite or non- composite

17. A method according to claim 16, wherein the determining is based on blind decoding of the CSI feedback.

18. A method according to claim 17, wherein the blind decoding is performed by applying a first- and/or a second decoding method

19. A method according to claim 18, wherein the first decoding method is associated with the non-composite feedback and the second decoding method is associated with the composite feedback

20. A method according to any of claims 17-19, wherein the blindly decoded CSI feedback is tested against a condition.

21 . A method according to claim 20, wherein the condition may be to check if the blindly decoded CSI feedback is:

- within an expected range

- greater than an expected value

22. A method according to claim 21 , wherein the expected value and/or the expected range is based on previously decoded CSI feedback.

23. A method according to any of claims 18-22, wherein the determining is based on at least one of: the first configured time instance - a second configured time instance being based on a second cell specific parameter

24. A method according to claim 23, wherein it is determined that CSI feedback is non-composite feedback, if the second configured time instance does not coincide with the first configured time instance.

25. A method according to any of claims 16-24, wherein the first- and second cell specific parameters are communicated to the first network node from, or via, at least one of:

- a second network node (RNC) - the first network node

- the wireless device

26. A method according to any of claims 23-25, wherein the first- and second cell specific parameters comprise one of:

- CQI feedback cycle (k) - CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit)

27. A first network node (NB), which is configured to control at least one HSDPA radio link in a cellular communications network and the cellular network supports HSDPA multiflow operation, the network node is further adapted to: - receive CSI feedback at a receiving time instance

- decode the CSI feedback if the receiving time instance and a first configured time instance coincide, wherein the first configured time instance being based on a first cell specific parameter - determine whether the received CSI feedback is composite or non-composite

28. A first network node according to claim 27, wherein the network node is adapted and/or configured to determine whether the received CSI feedback is composite or non-composite, based on blind decoding of the CSI feedback.

29. A first network node according to any of claims 27-31 , wherein the first network node is adapted and/or configured to determine if CSI feedback is composite or non-composite based on at least one of:

- the first configured time instance

- a second configured time instance being based on a second cell specific

parameter

30. A first network node according to claim 29, wherein the first network node first network node is configured and/or adapted to determine that CSI feedback is non-composite feedback, if the second configured time instance does not coincide with the first configured time instance.

31 . A first network node according to any of claims 29-30, wherein the first network node may be also adapted to receive the first- and second cell specific parameters from, or via, at least one of:

- a second network node (RNC)

- the first network node - the wireless device

32. A first network node according to any of claims 27-32, wherein the first network node is adapted to obtain and/or receive the first- and second cell specific parameters, the parameters comprise one of: CQI feedback cycle (k)

- CQI repetition factor (N_cqi_transmit)

- HARQ-ACK repetition factor (N_acknack_transmit)

33. A computer program (225; 235) comprising instructions which, when executed on a processing circuitry (210), cause the processing circuitry (210) to carry out and/or control the method according to any one of claims 1 -7.

34. A computer program (125; 135) comprising instructions which, when executed on a processing circuitry (1 10), cause the processing circuitry (1 10) to carry out and/or control the method according to any one of claims 16-26.

35. A carrier (120; 130) containing the computer program of claim 33, wherein the carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium.

36. A carrier (140; 150) containing the computer program of claim 34, wherein the carrier is one of an electronic signal, optical signal, radio signal, computer or processing circuitry readable storage medium.

37. A wireless device (200) adapted to being configured with a first- and a second HSDPA radio link for HSDPA multiflow operation in a cellular

communications network, wherein the wireless device (200) comprises:

- a receiving module(240), adapted to receive at least a first- and a second cell specific parameter, wherein the first cell specific parameter configures a first sending time instance for sending CSI feedback related to the first HSDPA radio link and wherein the second cell specific parameter configures a second sending time instance for sending the CSI feedback related to the second HSDPA radio link - a determining module (250), adapted to determine, based on the at least first- and second cell specific parameters, if the first- and second sending time instances coincide

- a sending module(260), adapted to send CSI feedback as a non- composite feedback

38. A network node (NB), comprising a controlling module (170) which is adapted to control at least one HSDPA radio link in a cellular communications network and the cellular network supports HSDPA multiflow operation and the network node further comprises: - a receiving module (140), adapted to receive CSI feedback at a receiving time instance

- a decoding module(150), adapted to, decode the CSI feedback if the receiving time instance and a first configured time instance coincide, the first configured time instance being based on a first cell specific parameter - a determining module(160), adapted to determine whether the received CSI feedback is composite or non-composite