NZ620524B2 - Ack/nack feedback method in wireless communication system - Google Patents

Abstract

Disclosed is a method for transmitting feedback information by a terminal in a wireless communication system employing time division duplex (TDD). The method comprises a user equipment (UE) receives a first subframe configuration information of a primary cell (PCell) from a base station. The UE also receives a second subframe configuration information of a secondary cell (SCell) from the base station. The UE then receives data on the SCell and determines feedback timing based on the first subframe configuration information and the second subframe configuration information. The UE transmits feedback information corresponding to the data based on the determined feedback timing to the base station. The first subframe configuration information is different from the second subframe configuration information. o receives a second subframe configuration information of a secondary cell (SCell) from the base station. The UE then receives data on the SCell and determines feedback timing based on the first subframe configuration information and the second subframe configuration information. The UE transmits feedback information corresponding to the data based on the determined feedback timing to the base station. The first subframe configuration information is different from the second subframe configuration information.

Description

WO 25059 ption Title of Invention: ACK/NACK FEEDBACK METHOD IN WIRELESS COMMUNICATION SYSTEM cal Field The present invention relates to a field of mobile communication technology, and more particularly, to an Acknowledgement (ACK)/ Non Acknowledgement (NACK) feedback method in a wireless communication system.

Background Art In the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) standard, a downlink transmission logy is based on Orthogonal Frequency Division Multiplexing (OFDM) and an uplink transmission technology is based on Single—Carrier Frequency Division Multiple Access (SC—FDMA).

The LTE system uses two types of frame structure, i.e., frame structure type 1 adopting ncy—Division Duplex (FDD) and frame structure type 2 adopting Time Division Duplex (TDD). Frame structure type 2 includes seven kinds of frame structure configurations. The proportion of downlink sub—frames in each kind of frame structure configuration is fixed, ranging from 40% to 90%. As shown in figure 1, it can be y perceived from figure 1 that each radio frame consists of 10 radio sub— frames, and numbered sequentially from zero. Take configuration 0 for example: Sub—frame 0 and ame 5 are used for sending downlink data, i.e., the sub—frame 0 and sub—frame 5 are used by the Evolved NodeB (eNB) for sending information to the User Equipment (UE).

Sub—frames 2, 3 and 4 and sub—frames 7, 8 and 9 are used for sending uplink data, i.e., the sub—frames 2, 3, 4, 7, 8 and 9 are used by the UE for sending ation to the eNB.

Sub—frame l and sub—frame 6 are known as special sub—frames, consisting of three special time slots. The three special time slots are respectively defined as Downlink Pilot Time Slot (DwPTS), Guard Period (GP) and Uplink Pilot Time Slot (UpPTS).

The length of time of the DwPTS, GP, and UpPTS is variable. The specific value of the length of the time is configured by the system. The special sub—frames are used for sending the downlink data, and can be regarded as truncated downlink sub—frames.

The subsequent evolution of the LTE system is known as the "LTE—Advanced," called LTE—A for short. An objective of the LTE—A is meeting system ements of the International Mobile Telecommunications (IMT)—Advanced advanced by the ITU.

A critical ed ive of the IMT—Advanced includes further enhanced data rate, interoperability/compatibility with other s and worldwide roaming charac— teristics, etc. The objective of the data rate for downlink is leps and the objective of the data rate for uplink is 500Mbps.

Based on the above objectives, a concept of r Aggregation (CA) is introduced into LTE version 10. The spectral efficiency of ss resources is further improved by aggregating le continuous or discontinuous carriers into system bandwidth up to 100 Mhz and using the Multiple—Input Multiple—Output (MIMO) logy applied in the LTE—A uplink and downlink. The system of LTE version 10 is already able to meet the system requirements of the IMT—Advanced. However, in the actual network deployment and system operation, in most cases, competition of the spectrum and scattered available um makes such a large—scale continuous spectrum ag— gregation unrealistic. In order to obtain the target peak rate of the system of LTE version 10, in the future, the system has to adopt the discontinuous spectrum allocation and bandwidth aggregation. While the discontinuous spectrum aggregation means that there are big differences between interferences of different frequency bands. ally for the network deployment of the Time Division (TD)—LTE system, the interference between the uplink and downlink severely restricts mances of the TD—LTE system.

Based on the above analysis, in the future evolution of the TD—LTE system, an important issue to be considered in the evolution of the TD—LTE system is applying different frame structure configurations to different Component Carriers (CC)s. In the system of LTE Rel—10, when a UE is configured with multiple CCs, an eNB notifies the UE of the number of the Primary Component Carrier (PCC) and the number of ag— gregated Secondary Component rs (SCC)s through high—level signaling. In on, when the le CCs ured for the UE are in different frequency bands, and the frame structure configuration of at least one CC is different from the frame structure of other CCs, how to design a timing relationship between a downlink data sub—frame Physical Downlink Shared Channel (PDSCH) and Uplink (UL) control information, and more specifically how to feed back the ACK/NACK becomes a key issue to be solved when the carrier aggregation between different bands adopts different frame structure configurations.

Disclosure of Invention Technical Problem At present, on the basis of rational technical analysis, the following two solutions are mainly adopted.

The first one is on the assumption that all UEs supporting a r aggregation technology n different bands and characteristics of different frame structure configurations includes at least two Power iers (PA)s and Radio frequency (RF) WO 25059 circuits. Specifically, refer to the feedback method described in figure 2, i.e., when all CCs of the UE are in two different bands and the frame structure configurations in either a different band are the same, while the frame structure in different bands is different, the eNB designates a CC for feeding back ACK/NACK information for each UE in each band through the high—level signaling. Each band continues to use an existing timing relationship between the PDSCH and UL ACK/NACK in its band according to each different frame structure configuration. Although this method can successfully feed back the ACK/NACK information, requires that all UEs supporting the r aggregation technology between different bands and characteristics of different frame structure configurations include at least two PAs, which y increases the cost of the Rel—ll terminal and restricts the ation and market of the Rel—ll products. Further, as for cell edge users with limited power, the characteristics of Cubic Metric (CM) needs to be considered when sending the UL ACK/NACK in— formation on multiple CCs, and the efficiency of the ier of the UE needs to be further reduced, which inevitably deteriorates the performances of the UL ACK/ ANCK and even makes the UL ACK/ANCK can not be correctly received for the cell edge users with insufficient power.

Therefore, the problem of the above method leads to a second method, i.e., merely g the UL ACK/NACK information on a single FCC to ensure that even low—end users with only one PA in the Rel—ll system still can benefit from the r ag— gregation technology n different bands with different frame structure config— urations, and continue to use the existing power control ism of the UL ACK/ NACK information. A typical method includes: designing a new timing relationship between the PDSCH and UL ACK/NACK for taking Load Balancing (LB) charac— teristics of the UL ACK/NACK into account. Although this method can tly feed back the ACK/NACK on the basis of overcoming the problem of the first , the biggest concern is that the new timing relationship between the PDSCH and UL ACK/ NACK needs a scheduler to use new ling policy for allocating and scheduling resources, i.e., the method needs to change the existing scheduler algorithms.

On the basis of the above analysis, the existing ACK/NACK feedback technical solutions have different problems. Therefore, finding a feasible timing relationship between the PDSCH and UL ACK/NACK, i.e. how to feed back ACK/NACK becomes a primary technical problem of the LTE ion version ll to be solved.

Solution to Problem In view of this, embodiments of the present invention provide an ACK/NACK feedback method in a wireless communication , by which the UE may adaptively feed back the ACK/NACK according to the configured frame structure con— WO 25059 figuration of the CC, the r aggregation between Bands of different frame structure configurations is effectively supported and the coexistence and performance optimization of different ication systems is implemented without limiting the number of amplifiers of the UE.

In order to achieve the above objective, the technical solution of the present invention is lished in the following way: An ACK/ NACK feedback method in a wireless communication system includes: determining, by a UE, number of public sub—frames, all of which are uplink sub— frame in FCC and SCC sub—frames of any radio frame in frame ure config— urations according to the frame structure configurations of the FCC and any SCC; selecting, by the UE, a uration, uplink sub—frames of which merely include sub—frames corresponding to the determined number of public sub—frames from existing seven kinds of frame structure configurations; and feeding back, by the UE, to a eNB ACK/NACK information corresponding to PDSCH in the SCC on the PCC adopting a timing relationship between the PDSCH and the ACK/NACK corresponding to the ed configuration.

The method further includes: feeding back, by the UE, to the eNB the ACK/NACK information corresponding to the PDSCH in the PCC on the PCC adopting the timing relationship between the PDSCH and ACK/NACK corresponding to the selected con— figuration.

The method further includes: g back, by the UE, to the eNB the ACK/NACK information corresponding to the PDSCH in the PCC on the PCC adopting the timing relationship between the PDSCH and the ACK/NACK corresponding to the frame structure configuration of the PCC.

When a bundled window of downlink data sub—frames determined by the UE includes uplink data sub—frames, the method r includes: mapping the ACK/NACK corresponding to the uplink data sub—frames into a Dis— continuous Transmission, DTX, status, or not feeding back any ACK/NACK in— formation.

When the UE is ured with more than two PCCs, before determining, by the UE, the number of public sub—frames, all of which are uplink sub—frame in FCC and any SCC sub—frames of a radio frame in the frame structure configurations, the method further includes: notifying, by the eNB, the UE of number of FCC for feeding back the ACK/NACK through Radio Resource l, RRC, signaling.

The method for selecting, by the UE, a configuration, uplink ames of which merely include sub—frames corresponding to the determined number of public sub— frames from existing seven kinds of frame structure configurations includes: supposing that in any radio frame of the frame structure configurations, a con— figuration ing two uplink and downlink sub—frame switching points is the con— figuration of the first class and the other configurations are the urations of the second class, the two kinds of configurations of UE are configuration A and con— figuration B; selecting, by the UE, configuration B when configuration A and configuration B belong to a same class of configuration, and tion of uplink sub—frames in con— figuration A is larger than that of configuration B; selecting, by the UE, a uration other than configuration 0 in configuration A and configuration B when configuration A and configuration B do not belong to a same class of configuration, and either of configuration A and configuration B is con— figuration 0; selecting, by the UE, a configuration other than configuration 6 in configuration A and configuration B when configuration A and configuration B do not belong to a same class of configuration, and neither of configuration A and configuration B is con— tion 0 and either of them is configuration 6; selecting, by the UE, configuration 5 when configuration A and configuration B do not belong to a class kind of configuration and either of configuration A and con— figuration B is configuration 5; f—l WOOD.) DON I—JI—JI—JI—J selecting, by the UE, uration 4 when (A, B) is (l, 3) or (1, 4); and selecting, by the UE, configuration 5 when (A, B) is (2, 3) or (2, 4).

An ACK/ NACK feedback method in a wireless ication system includes: 7—! U3 4; notifying, by a eNB, a UE of ured information of a FCC and all SCCs through high—level signaling; wherein the configured information of the FCC and all SCCs of the UE includes: a frame structure configuration of each CC configured for the UE, and further inlcudes: number of the FCC and all SCCs; determining, by the UE, a frame structure configuration according to the information of the frame structure configurations of the FCC and all SCCs sent from the eNB; and feeding back, by the UE, to the eNB, ACK/NACK ation corresponding to PDSCH in the SCCs on the PCC adopting a timing relationship between the PDSCH and the ACK/NACK corresponding to the determined frame structure configuration.

The method for determining, by the UE, a frame structure configuration according to the information of the frame structure configurations of the FCC and all SCCs sent from the eNB includes: supposing that in any radio frame of the frame structure configurations, a con— figuration ing two uplink and downlink sub—frame switching points is the con— figuration of the first class and the other configurations are the configurations of the second class, the two kinds of configurations of UE are configuration A and con— figuration B; determining, by the UE, configuration B when configuration A and configuration B belong to a same class of configuration, and proportion of uplink sub—frames in con— figuration A is larger than that of configuration B; determining, by the UE, a configuration other than configuration 0 in configuration A and configuration B when configuration A and configuration B do not belong to a same class of uration, and either of configuration A and configuration B is con— tion 0; determining, by the UE, a configuration other than configuration 6 in uration A and configuration B when uration A and uration B do not belong to a same class of configuration, and neither of configuration A and configuration B is con— figuration 0 and either of them is configuration 6; determining, by the UE, uration 5 when configuration A and configuration B do not belong to a same class of configuration and either of configuration A and con— figuration B is configuration 5; determining, by the UE, configuration 4 when (A, B) is (l, 3) or (1, 4); and determining, by the UE, configuration 5 when (A, B) is (2, 3) or (2, 4).

The method further includes: feeding back, by the UE, to the eNB the ACK/NACK information corresponding to the PDSCH in the PCC on the PCC adopting the timing relationship between the PDSCH and ACK/NACK corresponding to the determined configuration.

The method further includes: feeding back, by the UE, to the eNB the ACK/NACK ation corresponding to the PDSCH in the PCC on the PCC adopting the timing relationship between the PDSCH and ACK/NACK ponding to the frame structure configuration of the PCC.

When a bundled window of downlink data sub—frames determined by the UE includes uplink data sub—frames, the method further includes: mapping the CK corresponding to the uplink data sub—frames into a Dis— continuous Transmission, DTX, status, or not feeding back any ACK/NACK in— formation.

In view of the above cal solutions, with the ACK/NACK feedback method in the ss communication system provided by embodiments of the present invention, the UE determines the number of public sub—frames, all of which are uplink sub—frames in the FCC and SCC sub—frames of any radio frame according to the configured frame structure configurations of the FCC and any SCC, selects the configuration, the uplink frames of which merely include sub—frames corresponding to the determined number of the public sub—frames from the existing seven kinds of frame structure config— ns, and feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the SCC on the PCC adopting the timing relationship between the PDSCH and ACK/NACK corresponding to the selected configuration. Alternatively, the eNB notifies the UE of the configured information of the PCC and all SCCs through the evel signaling.

The UE ines a frame structure uration ing to the information of the frame structure configurations of the PCC and all SCCs sent from the eNB, and feeds back to the eNB the ACK/NACK information ponding to the PDSCH in the SCCs on the PCC using the timing relationship between the PDSCH and ACK/NACK corresponding to the determined frame structure configuration. Further, when the UE is configured with multiple CCs, and the frame structure configuration of at least one CC is different from the frame structure configurations of the other CCs, the method of the present invention may adaptively select and determine a timing relationship between the PDSCH and UL ACK/NACK according to the configured frame structure configuration of the CC without changing the existing thm of the scheduler, and feed back the CK information on the PCC. Therefore, the ACK/NACK feedback method of the present invention may effectively support the carrier aggregation between Bands of different frame structure configurations and implement the coexistence and performance optimization of different communication systems without limiting the number of iers of the UE.

Alternatively, it is an object of the invention to at least provide the public with a useful choice.

Unless the t clearly requires otherwise, throughout the description and claims the terms “comprise”, “comprising” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense. That is, in the sense of “including, but not limited to”.

Advantageous s of Invention The ACK/NACK feedback method of the present invention may effectively support the carrier aggregation between Bands of different frame structure configurations and implement the coexistence and performance optimization of different communication systems without limiting the number of amplifiers of the UE.

Brief Description of gs Figure 1 is a schematic diagram illustrating frame ure configurations of an existing TDLTE system; Figure 2 is a scene schematic diagram illustrating an existing ACK/NACK feedback method; Figure 3 is a work flow chart of ACK/NACK feedback method one according to an embodiment of the present invention; Figure 4 is a scene schematic diagram illustrating a first embodiment of the present invention for determining ACK/NACK sub-frames; Figure 5 is a scene schematic m illustrating a second ment of the present invention for determining CK sub-frames; Figure 6 is a scene schematic diagram illustrating a third embodiment of the present invention for ining ACK/NACK sub-frames; Figure 7 is a scene schematic diagram illustrating a fourth embodiment of the present invention for ining ACK/NACK sub—frames; Figure 8 is a scene schematic diagram rating a fifth embodiment of the present invention for determining CK sub—frames; and Figure 9 is a work flow chart of ACK/NACK feedback method two according to an embodiment of the present invention.

Mode for the Invention The present invention is further described in detail after with reference to the accompanying drawings to make the objective, technical solution and merits thereof more apparent.

The main idea of the present invention is: UE determines number of public sub—frames, all of which are uplink ames in the FCC and SCC sub—frames of any radio frame in the frame structure urations according to the configured frame structure configurations of the FCC and any SCC.

The UE s a configuration, the uplink frames of which merely include sub—frames corresponding to the determined number of the public sub—frames, from the existing seven kinds of frame structure configurations. The UE feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the SCC on the PCC adopting a timing relationship between the PDSCH and ACK/NACK corresponding to the selected configuration.

Alternatively, the eNB es the UE of the ured information of the FCC and all SCCs through high—level signaling. The configured information of the FCC and all SCCs of the UE includes the frame structure configuration of each CC configured for the UE, and further includes the number of the FCC and all SCCs. The UE determines a frame structure configuration according to the information of the frame structure con— figurations of the FCC and all SCCs sent from the eNB. The UE feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the SCCs on the PCC adopting the timing relationship between the PDSCH and CK corresponding to the determined frame structure configuration.

Figure 3 illustrates a work flow of ACK/NACK feedback method one according to an embodiment of the present invention. As shown in figure 3, the flow includes: Block 301: UE determines number of public sub—frames, all of which are uplink sub— frames in the FCC and SCC sub—frames of any radio frame in the frame structure con— figurations according to the configured frame structure configurations of the FCC and any SCC.

It should be noted that when the UE is configured with more than two PCCs, the CC for feeding back the CK is one of the PCCs. Therefore, before executing this block, the eNB notifies the UE of the number of the PCC used for feeding back the WO 25059 2012/006517 ACK/NACK through the Radio Resource Control (RRC) signaling.

Block 302: The UE selects a uration, the uplink frames of which merely include sub—frames corresponding to the determined number of the public ames, from the seven kinds of existing frame structure configurations.

The UE selects the uration, the uplink frames of which merely include sub— frames corresponding to the determined number of the public sub—frames, i.e., selects the frame structure configuration, in which the ames except for the uplink sub— frames, i.e. the sub—frames corresponding to the determined number of the public sub— frames are downlink sub—frames. In this block, the UE selecting the configuration, the uplink frames of which merely e sub—frames corresponding to the determined number of the public sub—frames, from the seven kinds of existing frame structure con— figurations ically includes: Suppose that in the frame structure configuration and any radio frame, the con— figuration including two uplink and downlink sub—frame switching points is the con— figuration of the first class and the other configurations are the configurations of the second class. The two kinds of configurations of UE are configuration A and con— figuration B.

When configuration A and configuration B belong to a same class of uration, and the proportion of the uplink sub—frames in configuration A is larger than that of configuration B, the UE selects configuration B.

When configuration A and configuration B do not belong to a same class of con— figuration, and either of configuration A and configuration B is configuration 0, the UE selects the configuration other than the configuration 0 in configuration A and con— figuration B.

When configuration A and configuration B do not belong to a same class of con— figuration, neither of configuration A and configuration B is configuration 0 and either of them is configuration 6, the UE selects the configuration other than configuration 6 in configuration A and configuration B.

When configuration A and configuration B do not belong to a same class of con— figuration and either of configurations A and B is configuration 5, the UE selects the configuration 5.

When (A, B) is (l, 3) or (1, 4), the UE selects the configuration 4.

When (A, B) is (2, 3) or (2, 4), the UE selects the configuration 5.

Table 1 shows the result of frame structure urations selected from the two different kinds of the frame structure configurations. As shown in table 1, one is frame structure configuration A, the other one is frame structure configuration B. The UE finds existing configuration C which is backward compatible frame ure con— figuration with the values of configuration A and configuration B. Configuration C may be one of uration A and configuration B, or may be a new kind of frame ure configuration.

Table 1 [Table 1] Frame structure configuration A 0 l 2 3 4 5 6 Frame 0 l 2 3 4 5 6 structure 1 1 2 4 4 5 1 configuration 2 2 2 5 5 5 2 B 3 3 4 5 4 5 3 4 4 4 5 4 5 4 5 5 5 5 5 5 6 6 l 2 3 4 5 Block 303: The UE feeds back to the eNB the ACK/NACK information corre— sponding to the PDSCH in the SCC on the PCC using the timing onship between the PDSCH and ACK/NACK corresponding to the selected configuration.

It should be noted that in this block, for the PDSCH of the PCC, two ACK/NACK feedback manners may be adopted. One is the same as that of SCC, i.e., feeding back the ACK/NACK information on the PCC according to the timing relationship between the PDSCH and ACK/NACK corresponding to the selected configuration, That is, the UE may feed back the ACK/NACK information corresponding to all downlink data on a single CC, so that make the UL ACK/NACK obtained by mapping the FCC and SCC exactly the same as the timing relationship between the downlink data sub—frames. The other is feeding back the ACK/NACK information on the PCC according to the ACK/ NACK timing onship determined by its own frame structure uration.

It should be noted that, for any configured CC, when the ACK/NACK information is fed back according to the timing onship between the PDSCH and ACK/NACK corresponding to the selected configuration, and a bundled window of the downlink data sub—frames determined by the UE includes the uplink data sub—frames, the ACK/ NACK corresponding to the uplink data sub—frames are definitively mapped into a Dis— uous Transmission (DTX) status, or not feeding back any ACK/NACK in— formation.

At this point, the whole work flow of ACK/NACK feedback method one of the present invention is finished. In order to make the method of the present ion more apparent, examples are given hereafter for description.

Embodiment One In this embodiment, e that the UE is configured with two CCs, the number of which is CCO and CCl. CCO is FCC and CCl is SCC. Based on the consideration of minimized adjacent channel interference, CCO adopts frame structure uration 1, while CCl adopts frame structure configuration 2. Refer to the scene schematic diagram shown in figure 4 for the method for determining the ACK/NACK sub— frames. As shown in figure 4, the method includes: Step 401: The UE determines the number of uplink public sub—frames, i.e. designates the number of the public uplink ames as sub—frame 2 and ame 7 according to the frame structure configurations of FCC and SCC.

Step 402: The UE selects the configuration, i.e., the frame structure configuration 2 in Frame Structure 2 (FS2), the uplink sub—frames of which merely include sub—frame 2 and sub—frame 7 from the existing seven kinds of frame structure configurations according to the result of step 401.

Step 403: The UE feeds back the ACK/NACK information for the FCC and all SCCs adopting the timing onship between the PDSCH and ACK/NACK corresponding to the frame ure configuration 2 in the FS2.

It should be noted that in this embodiment, the PCC feeds back the ACK/NACK in— ion according to the timing relationship between the PDSCH and CK corresponding to the selected configuration. Thus, the UL ACK/NACK obtained by mapping the FCC and SCC is exactly the same as the timing relationship between the downlink data sub—frames.

Specifically, in this embodiment, both the eNB and UE definitely know that when specific sub—frames (the characteristics are that in the configured CC, this sub—frame is the downlink sub—frame of at least one CC, and meanwhile is the uplink sub—frame of at least one CC, such as, sub—frames 3 and 8 in figure 4) in the bundled window are uplink sub—frames of some CCs, the corresponding ACK/NACK mapping of the specific sub—frames in the bundled window is the DTC status.

Embodiment Two In this embodiment, e that the UE is configured with two CCs, the number of which is CCO and CCl. CCO is FCC and CC1 is SCC. Based on the consideration of minimized adjacent channel interference, CCO adopts frame structure configuration 1, while CC1 adopts frame structure configuration 3. Refer to the scene schematic diagram shown in figure 5 for the method for determining the ACK/NACK sub— frames. As shown in figure 5, the method es: Step 501: The UE determines the number of uplink public sub—frames, i.e. designates the number of the public uplink sub—frames as sub—frame 2 and sub—frame 3 according to the frame structure configurations of FCC and SCC.

Step 502: The UE selects the configuration, i.e., the frame ure configuration 4 in Frame ure 2 (FS2), the uplink sub—frames of which merely include sub—frame 2 and sub—frame 3 from the existing seven kinds of frame structure configurations according to the result of step 501.

Step 503: The UE feeds back the ACK/NACK information for the FCC and all SCCs adopting the timing relationship between the PDSCH and ACK/NACK corresponding to the frame structure configuration 4 in the FS2.

It should be noted that same as embodiment one, the PCC also feeds back the ACK/ NACK information according to the timing relationship between the PDSCH and ACK/NACK corresponding to the selected configuration.

Specifically, in this embodiment, both the eNB and UE definitely know that when specific sub—frames (the teristics are that in the ured CC, this sub—frame is the downlink sub—frame of at least one CC, and meanwhile is the uplink sub—frame of at least one CC, such as, sub—frames 7 and 8 in figure 5) in the bundled window are uplink sub—frames of some CCs, this embodiment does not feed back any ACK/NACK information for the ic sub—frames in the bundled window.

Embodiment Three In this embodiment, suppose that the UE is configured with two CCs, the number of which is CCO and CCl. CCO is FCC and CCl is SCC. Based on the eration of minimized adjacent channel interference, CCO adopts frame structure configuration 2, while CCl adopts frame structure configuration 4. Refer to the scene schematic diagram shown in figure 6 for the method for determining the CK sub— frames. As shown in figure 6, the method es: Step 601: The UE determines the number of uplink public ames, i.e. designates the number of the public uplink ames as sub—frame 2 according to the frame structure configurations of FCC and SCC.

Step 602: The UE selects the configuration, i.e., the frame structure uration 5 in Frame Structure 2 (FS2), the uplink sub—frames of which merely include sub—frame 2 from the existing seven kinds of frame structure configurations according to the result of step 601.

Step 603: The UE feeds back the ACK/NACK information for the FCC and all SCCs adopting the timing relationship between the PDSCH and ACK/NACK ponding to the frame structure configuration 5 in the FS2.

Similarly, in this embodiment, both the eNB and UE definitely know that when specific sub—frames (the characteristics are that in the configured CC, this sub—frame is the downlink ame of at least one CC, and meanwhile is the uplink sub—frame of at least one CC, such as, sub—frame 3 in figure 6) in the bundled window are uplink sub—frames of some CCs, the corresponding ACK/NACK g of the specific sub— frames in the bundled window is the DTC status.

Embodiment Four In this embodiment, suppose that the UE is configured with two CCs, the number of which is CCO and CCl. CCO is FCC and CCl is SCC. Based on the consideration of minimized adjacent channel interference, CCO adopts frame structure configuration 2, WO 25059 while CC1 adopts frame structure uration 4. Refer to the scene schematic diagram shown in figure 7 for the method for determining the ACK/NACK sub— frames. As shown in figure 7, the method includes: Step 701: The UE determines the number of uplink public sub—frames, i.e. the sub— frame 2 in the figure according to the frame structure configurations of the FCC and SCC.

Step 702: The UE s the configuration, i.e., the frame structure configuration 5 in Frame Structure 2 (FS2), the uplink sub—frames of which merely include sub—frame 2 from the existing seven kinds of frame structure configurations according to the result of step 701.

Step 703: The UE merely feeds back the ACK/NACK information for the SCC adopting the timing relationship between the PDSCH and ACK/NACK corresponding to the frame structure configuration 5 in the FS2. While the PCC still determines the timing relationship n the PDSCH and ACK/NACK according to the frame structure configuration of a real PCC.

It should be noted that in this embodiment, the PCC feeds back the CK in— formation adopting its own frame structure configuration. r, it should be noted that in this ment, both the eNB and UE definitely know that when specific sub—frames (the characteristics are that in the configured CC, this sub—frame is the downlink sub—frame of at least one CC, and meanwhile is the uplink sub—frame of at least one CC, such as, sub—frame 7 in figure 7) in the bundled window are uplink sub—frames of some CCs, this embodiment does not feed back any CK ation for the specific sub—frames in the bundled .

Embodiment Five In this embodiment, suppose that the UE is configured with three CCs, respectively in different bands. Suppose that the number of the three CCs is CCO (in Band I), CC1 (in Band II) and CC2 (in Band III). CCO is PCC, CC1 is SCCO and CC2 is SCCl.

Based on the consideration of minimized adjacent channel interference, CCO adopts frame structure configuration 1, CC1 adopts frame structure uration 3 and CC2 adopts frame structure configuration 0. Refer to the scene schematic diagram shown in figure 8 for the method for determining the ACK/NACK sub—frames. As shown in figure 8, the method includes: Step 800: The UE respectively determines the timing relationship between the PDSCH and ACK/NACK for each SCC with different frame structure configuration according to the frame structure configurations of the PCC, SCCO and SCC1, which specifically includes: Step 801: The UE determines the number of uplink public sub—frames as sub—frame 2 according to the frame structure configurations of FCC and SCCO.

Step 802: The UE selects the configuration, i.e., the frame structure configuration 4 in Frame Structure 2 (FS2), the uplink sub—frames of which merely include sub—frame 2 and sub—frame 3 from the existing seven kinds of frame structure configurations ing to the result of step 801.

Step 803: The UE determines the number of the uplink public sub—frames as sub— frame 2, ame 3, sub—frame 7 and sub—frame 8 according to the frame structure configurations of FCC and SCCl.

Step 804: The UE selects the configuration, i.e., the frame structure configuration 1 in Frame Structure 2 (FS2), the uplink sub—frames of which merely include sub—frames 2, 3, 7 and 8 from the existing seven kinds of frame structure configurations according to the result of step 803.

Step 805: The UE merely adopts the timing relationship between the PDSCH and ACK/NACK corresponding to the frame structure configuration ined in steps 802 and 804 for the SCCs. That is, the UE feeds back the ACK/NACK information for SCCO adopting the timing relationship between the PDSCH and ACK/NACK corre— sponding to the frame structure configuration 4 determined,and feeds back the ACK/ NACK information for SCCl adopting the timing relationship between the PDSCH and ACK/NACK ponding to frame structure configuration 1. But, the PCC sill determines the timing relationship between the PDSCH and ACK/NACK according to its frame structure configuration.

It should be noted that in the above embodiments, when the UE is configured with more than two PCCs, the eNB notifies the UE of the number of the PCC for feeding back the CK through the RRC ing.

All the above embodiments are illustrating examples, in actual ation, the PCC not only can feed back the ACK/NACK information according to the timing rela— ip between the PDSCH and ACK/NACK corresponding to the selected con— tion, but also can feed back the ACK/NACK information according its own frame structure configuration. Further, for the specific sub—frames in the bundled window, the ACK/NACK corresponding to the uplink data sub—frames can be tely either mapped into the DTC status, or not g back any ACK/NACK in— formation.

Corresponding to the flow of method one shown in figure 3, figure 9 shows a work flow of ACK/NACK feedback method two of the present invention. As shown in figure 9, the flow includes: Block 901: The eNB notifies UE of the configured information of the FCC and all SCCs through high—level signaling. The configured information of the FCC and all SCCs of the UE includes: the frame structure uration of each CC configured for the UE, and further includes the number of the FCC and all SCCs.

Block 902: The UE determines a kind of frame structure configuration according to the ation of the frame structure configurations of the FCC and all SCCs sent from the eNB.

In this block, the UE may uniquely determine a kind of backward compatible frame structure configuration ing to the configured information of the CCs sent from the eNB. The UE determines a kind of frame ure configurations as shown in table 1 according to the information of the frame structure configurations of the FCC and all SCCs sent from the eNB, which specifically includes: Suppose that in the information of the CC configured for the UE and any radio frame, the configuration including two uplink and downlink sub—frame switching points is the configuration of the first class and the other configurations are the config— urations of the second class. The two kinds of configurations of UE are configuration A and configuration B.

When configuration A and configuration B belong to a same class of configuration, and the proportion of the uplink sub—frames in configuration A is larger than that of configuration B, configuration B is ined.

When configuration A and configuration B do not belong to a same class of con— figuration, and either of configuration A and configuration B is configuration 0, the configuration other than the configuration 0 in configuration A and configuration B is determined.

When configuration A and uration B do not belong to a same class of con— figuration, neither of configurations A and B is uration 0 and either of them is configuration 6, the configuration other than the configuration 6 in configuration A and configuration B is determined.

When configuration A and configuration B do not belong to a same class of con— figuration and either of configurations A and B is configuration 5, configuration 5 is determined.

When (A, B) is (l, 3) or (1, 4), configuration 4 is determined.

When (A, B) is (2, 3) or (2, 4), configuration 5 is determined.

Block 903: The UE feeds back to the eNB the ACK/NACK information corre— ng to the PDSCH in the SCCs on the PCC adopting the timing relationship between the PDCH and CK corresponding to the determined frame ure configuration.

Further, the UE feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the PCC on the PCC ng the timing relationship between the PDCH and ACK/NACK corresponding to the determined configuration. Alternatively, the UE feeds back to the eNB the CK information corresponding to the PDSCH in the PCC on the PCC adopting the timing relationship between the PDCH 2012/006517 and ACK/NACK corresponding to its own frame structure configuration.

It should be noted that when the bundled window of the downlink data sub—frames determined by the UE includes the uplink data sub—frames, the ACK/NACK corre— sponding to the uplink data ames are definitively mapped into a DTX status, or not feeding back any CK information.

At this point, the whole work flow of ACK/NACK feedback method of the present invention is finished.

In brief, with the ACK/NACK feedback method in the wireless communication system ed by embodiments of the present ion, the UE determines the number of public sub—frames, all of which are uplink sub—frames in the FCC and SCC sub—frames of any radio frame according to the ured frame structure config— urations of the FCC and any SCC, selects the configuration, the uplink frames of which merely include sub—frames corresponding to the determined number of the public sub— frames from the ng seven kinds of frame structure configurations, and feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the SCC on the PCC adopting the timing relationship between the PDSCH and ACK/NACK corre— sponding to the selected configuration. Alternatively, the eNB notifies the UE of the ured information of the FCC and all SCCs through the high—level signaling. The UE determines a frame structure configuration according to the information of the frame structure configurations of the FCC and all SCCs sent from the eNB, and feeds back to the eNB the ACK/NACK information corresponding to the PDSCH in the SCCs on the PCC using the timing relationship n the PDSCH and ACK/NACK corresponding to the determined frame structure configuration. r, when the UE is configured with multiple CCs, and the frame structure con— figuration of at least one CC is different from the frame structure configurations of the other CCs, the method of the present invention may adaptively select and determine a timing relationship between the PDSCH and UL ACK/NACK according to the configured frame structure configuration of the CC without changing the existing algorithm of the scheduler, and feed back the ACK/NACK information on the PCC.

Therefore, the ACK/NACK feedback method of the present invention may ively support the carrier aggregation between Bands of different frame structure config— urations and implement the coexistence and performance optimization of different communication systems t limiting the number of amplifiers of the UE.

The foregoing only describes preferred examples of the present ion and is not used to limit the protection scope of the present invention. Any modification, equivalent substitution and improvement t departing from the spirit and principle of the present invention are within the protection scope of the present invention.

WO 25059

Claims (1)

1. CLAIMS 【Claim 1】 A method for transmitting feedback information by a terminal in a wireless communication system employing time division duplex, TDD, the method comprising: receiving, from a base n, first subframe configuration information of a primary cell, PCell; receiving, from the base station, second subframe configuration information of a secondary cell, SCell; receiving data on the SCell; determining feedback timing based on the first subframe configuration information and the second subframe uration information; and transmitting, to the base station, feedback information corresponding to the data based on the determined feedback timing, n the first subframe configuration information is different from the second subframe configuration information. 【Claim 2】The method of claim 1, wherein the determined feedback timing which is the uplink subframe in a same subframe number based on first subframe configuration information and the second subframe uration information. 【Claim 3】 The method of claim 1, wherein transmitting feedback ation further comprising: transmitting the feedback information according to a timing onship between the data and feedback information corresponding to the determined feedback timing. 【Claim 4】The method of claim 1, further comprising” receiving data on the PCell; and transmitting feedback information corresponding to the data received on the PCell based on the first subframe configuration information of the PCell. 【Claim 5】The method of claim 1, wherein the determining feedback timing further comprising: determining at least one subframe which is an uplink me in the PCell and the SCell based on the TDD frame uration information of the PCell and the SCell; identifying TDD frame structure configuration information based on the determined at least one me; and determining feedback timing based on the identified TDD frame structure configuration information. 【Claim 6】The method of claim 5, wherein the identifying further comprising: fying TDD frame structure configuration information ing the at least one uplink subframe in the determined at least one me. 【Claim7】 The method of claim 5, wherein TDD frame structure configuration is identified from the predetermined seven kinds of time division duplex, TDD, frame structure configurations. 【Claim 8】 A terminal for transmitting feedback ation in a wireless communication system employing time division duplex, TDD, the terminal comprising: a transceiver configured to transmit and receiving a signal; and a controller configured to: control the transceiver for receiving first subframe configuration information of a primary cell, PCell, receiving second subframe configuration information of a secondary cell, SCell, from a base station and receiving data on the SCell, determine feedback timing based on the first subframe configuration information and the second subframe configuration information, l the transceiver for transmitting, to the base station, feedback information corresponding to the data based on the ined feedback , wherein the first subframe configuration information is different from the second subframe configuration. 【Claim 9】 The terminal of claim 8, wherein the determined feedback timing which is the uplink subframe in a same me number based on first subframe configuration information and the second subframe configuration information. 【Claim 10】The al of claim 8, wherein the controller further configured to: control the transceiver for receiving data on the PCell and itting feedback information corresponding to the data received on the PCell based on the first subframe configuration information of the PCell. 【Claim 11】The terminal of claim 8, wherein the ller configured to: control the transceiver for receiving data on the PCell and transmitting feedback information ponding to the data received on the PCell based on the first subframe configuration information of the PCell. [Claim 12] The al of claim 8, wherein the controller further configured to: ine at least one subframe which is an uplink subframe in the PCell and the SCell based on the TDD frame configuration information of the PCell and the SCell; identify TDD frame structure configuration information based on the determined at least one subframe; and determine feedback timing based on the identified TDD frame structure configuration information. [Claim 13] The terminal of claim 12, wherein the ller further configured to: identify TDD frame ure configuration information including the at least one uplink subframe in the determined at least one subframe. [Claim 14] The terminal of claim 12, wherein TDD frame structure configuration information is identified from the predetermined seven kinds of time division duplex, TDD, frame structure configurations. [Claim 15] A method for transmitting feedback ation by a terminal in a wireless communication system substantially as herein described with reference to any one of the embodiments illustrated in the accompanying drawings,