CN112005518B

CN112005518B - Transmission of control and data

Info

Publication number: CN112005518B
Application number: CN201980023712.6A
Authority: CN
Inventors: 欧麦尔·萨利姆; 布鲁诺·杰裘克斯; 赛巴斯钦·华格纳
Original assignee: JRD Communication Shenzhen Ltd
Current assignee: JRD Communication Shenzhen Ltd
Priority date: 2018-04-06
Filing date: 2019-04-01
Publication date: 2023-05-23
Anticipated expiration: 2039-04-01
Also published as: GB201805790D0; GB2572646B; WO2019192411A1; GB2572646A; CN112005518A

Abstract

A method of transmitting data and control information, wherein the resources that transmission can be expected to use are predefined. A message may be sent in a predefined area and decoded at the receiving end. The message may include both control information and data.

Description

Transmission of control and data

Technical Field

The following disclosure relates to transmission of downlink data, and more particularly to systems that improve downlink communication efficiency.

Background

Wireless communication systems, such as third generation mobile phone standards and technologies, are well known, and the third generation partnership project (3 GPP) has developed such 3G standards and technologies, and in general, third generation wireless communications have been developed to the extent that macrocell mobile phone communications are supported, communication systems and networks have been developed toward broadband and mobile systems.

In a cellular wireless communication system, a User Equipment (UE) is connected to a radio access network (Radio Access Network, RAN) by a wireless link. The RAN includes a set of base stations (base stations) providing radio links to UEs located in cells covered by the base stations and includes an interface to a Core Network (CN) having a function of controlling the overall Network. It is understood that the RAN and CN each perform a corresponding function with respect to the entire network. For convenience, the term "cellular network" will be used to represent a combined hiccup of RAN & CN, but it will be understood that the term is also used to represent each system for performing the disclosed functions.

The third generation partnership project has evolved a so-called Long Term Evolution (LTE) system, an evolved universal mobile telecommunications system regional radio access network (E-UTRAN), for a mobile access network of one or more macro cells supported by base stations called enodebs or enbs (evolved nodebs). Recently, LTE has evolved further towards so-called 5G or New Radio (NR) systems, where one or more cells are supported by a base station called a gNB. When NR is proposed, an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) physical transport format is utilized.

The trend in wireless communication is toward services that provide lower latency and higher reliability. For example, NR is intended to support Ultra-reliable and low-latency communication (URLLC). A user plane delay of 1ms has been proposed with a reliability of 99.99999%. Other types of services to be provided include enhanced Mobile BroadBand (emmbb) for high data rates, and mass Machine-type communication (mctc) supporting a large number of devices with energy efficient communication channels that are long in service life.

Communication over a physical radio link is defined by a plurality of channels, e.g., a physical downlink control channel (Physical Downlink Control Channel, PDCCH) is used to transmit control information, especially downlink control information (Downlink Control Information, DCI), which defines how data is transmitted to the UE over a physical downlink shared channel (Physical Downlink Shared Channel, PDSCH). Successful reception of data at the UE side requires a reception and decoding procedure of the PDCCH channel and the PDSCH channel.

The DCI in the PDCCH carries scheduling and control information related to data (PDSCH). The scheduling information is mainly used to indicate to the UE which time-frequency resources are allocated for transmission of its associated data (PDSCH). The control information in the DCI for downlink transmission includes other necessary parameters that enable the UE to decode the scheduled data. These parameters may include, for example, modulation, coding scheme, parameters related to Hybrid-automatic-repeat-request (Hybrid-automatic-repeat-request) and parameters related to uplink response.

DCI is one specific message defined in TS 38.212 for NR and is carried on a PDCCH channel. The DCI conveys downlink and uplink scheduling information, a request for aperiodic CQI reports, or uplink power control commands of one cell and one RNTI, as defined in section 7.3 in TS 38.212.

With respect to the downlink physical channel, particularly the PDCCH, the following terminology will generally be used. These specific examples are with respect to NR, but the principles are equally applicable to protocols of other physical channels.

A Resource Block (RB) is a minimum unit of time/frequency resources that can be allocated to a user. The resource blocks are x-kHz wide in frequency and 1 slot long in time. The number of subcarriers used for each resource block of PDCCH is 12, the exact value of x depends on the subcarrier spacing (x=12 x scs), which may be 15kHz, 30kHz, 60kHz, etc. In terms of time, the default slot length in NR is 14 OFDM symbols, but small slot lengths (e.g., 1,2, 3 OFDM symbols, up to 13 OFDM symbols) may also be present. The exact duration of one slot in milliseconds (ms) depends on the number of OFDM symbols and SCS, e.g. 1 slot length is 1ms in case of 15kHz SCS and 14 OFDM symbols.

During one OFDM symbol, a resource-element group (REG) is equal to one RB.

The control-channel element (CCE) is composed of 6 REGs.

The PDCCH is composed of one or more CCEs (e.g., L ε {1,2,4,8 }). This number is defined as CCE aggregation level (aggregation level, AL).

For PDCCH blind decoding, for each CCE AL in each DCI format size, the combination of ALs and the number of PDCCH candidates that can be monitored by the UE may be configured.

For each serving cell, each UE is configured with multiple sets of control resources (control resource set, CORESET) to monitor the PDCCH channel. Each CORESET is defined by: start OFDM symbol, duration (consecutive symbols, up to 3 symbols), RB group, CCE to REG mapping (and in case of interlace mapping, REG bundle size).

In time (and frequency, where B is greater than the CORESET size over the symbol), B consecutive REGs form one REG bundle.

The distributed resource mapping is achieved by an interleaving operation, and this interleaving operation is performed for REG bundles. In case of CCE to REG non-interlace mapping, b=6.

In the case of CCE to REG interleaving mapping, B ε {2,6} for CORESET of 1 or 2 symbols and B ε {3,6} for CORESETB of 3 symbols.

The PDCCH search space under CCE AL L is defined by a set of PDCCH candidates under CCE AL.

Cellular wireless communication systems typically utilize HARQ-based protocols to improve reliability, but at the cost of increased delay. Using the HARQ protocols used for PDCCH and PDSCH to meet the requirements of URLLC service for delay is challenging and new methods may be needed to achieve transmission of these channels.

The 3GPP generally defines the term "reliability" in TR 38.802 as the probability of success R of transmitting X bits in L seconds. L refers to the time it takes to transmit a small packet from the ingress point of a radio protocol layer 2/3SDU to the egress point of the radio protocol layer 2/3SDU in the radio interface at a certain channel quality Q (e.g. in case of an edge of coverage). ).

The boundaries L of this delay include transmission delay, processing delay, retransmission delay (if any) and queuing/scheduling delay (including scheduling requests, if any, also authorized receipt).

In this document, it should also be noted that spectral efficiency should be considered when attempting to achieve reliability goals.

Regarding reliability targets in the URLLC scenario, NR is considered "for one seal" in TR 38.913In one transmission of packets, the general reliability requirements of URLLC are (1-10) with 32 bytes and a user interface delay of 1ms ^-5 )。”

In the case of one normal single-shot transmission (i.e., without HARQ retransmissions or repetition), the reliability R can be derived by:

R＝R _c R _d ，

wherein R is _c And R is _d The probabilities of successful transmission of PDCCH and PDSCH are represented, respectively. For simplicity, it is assumed that the impact of the false alarm probability is negligible (i.e., an error that is erroneously detected by the UE as a valid PDCCH without DCI transmission. A sufficiently large CRC (e.g., 24 bits) may lead to this situation when encoding DCI.

Conversely, the probability of erroneous packet transmission P (=1-R) is given by:

P＝1-(1-P _c )(1-P _d )，

wherein P is _c And P _d The probabilities of PDCCH and PDSCH erroneous transmissions are represented, respectively.

Thus, the reliability target of NR (> 99.999% reliability, or conversely, < 0.001% error probability) may be determined by, for example, a combination of error probabilities of the channels (e.g., P) _c ＝8·10 ^-6 And P _d ＝2·10 ^-6 ) To obtain the product.

In the case of multiple transmissions, several additional factors control the transmission reliability. For example, assuming that HARQ is not combined together, reliability for a conventional two-transmit transmission may be given by:

R＝R _c R _d1 +(1-R _c )R _DTX R _c R _d2 +R _c (1-R _d1 )R _N R _c R _d2 ，

wherein R is _d1 And R is _d2 Respectively representing the probability of successful PDSCH primary transmission and PDSCH retransmission; r is R _DTX Represents the probability that the gNB detects DTX or NACK when the UE "sends" DTX on the UL (i.e., nothing is sent); r is R _N Indicating that when the UE transmits NACK, gNBProbability of DTX or NACK detected.

To the right of the above equation, the first term used for summation is on successful reception of initial transmission, the second term is on successful reception of retransmission in case of PDCCH detection failure, and the third term is on successful reception of retransmission in case of PDSCH initial decoding failure.

There are many methods for improving the reliability of control channel transmissions, but these methods may involve the use of more transmission resources. However, there may be insufficient control channel resources to schedule transmissions to fully utilize the data transmission capacity, and thus the data transmission capacity may be left unused, resulting in inefficient use of resources.

Multiple transmissions with or without adaptive HARQ characteristics may improve reliability, but this is limited under the constraint of delay. In cases where traffic is heavy and there is a strict delay requirement, it is likely that the network must employ a single transmission best effort to meet both delay and reliability requirements.

With PDCCH design, the aggregation level is typically increased when the network becomes aware that the user cannot properly decode the control information. An increase in the aggregation level means that more resources are used to encode the control information, which results in a reduced coding rate and a higher robustness of the transmission to errors. The use of a higher aggregation level consumes a large amount of resources, which may result in other users not being able to use the control resources.

Fig. 1 shows a schematic diagram of transmission resources in an OFDM transmission system. Each slot 100 is divided into a control area 101 and a data area 102. The control region is used to transmit control information, e.g., PDCCH, to schedule transmission of PDSCH channels 103 in the data region 102 of the slot.

The URLLC service typically transmits small packets at unpredictable intervals. Transmitting a control message to schedule each data packet requires a significant amount of resources and the overhead of such a control message may become commensurate with the size of the data being transmitted. This is an inefficient use of resources. Furthermore, the subsequent transmission of control information accompanying the data increases the delay of the communication channel, especially if retransmissions are required to achieve the required level of reliability.

The present invention seeks to address at least some of the significant problems in the art.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

A method of transmitting data from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the base station, allocating a resource region in the OFDM slot for transmission of the combined data and control information message; transmitting an indication of the allocated resource region to the UE; and transmitting a data and control information message including a combination of the data portion and the control portion to the UE in the allocated resource region.

The indication of the allocated resource region may comprise a periodicity according to which the resource region is repeated.

The allocated resource region may overlap with the control region of the OFDM slot in whole or in part.

The indication of the allocated resource region may comprise information defining a transport format of the combined data and control information message.

The indication of the allocated resource region may be sent in an RRC message.

The combined data and control information message may include an indication of resources in a data region of the OFDM slot for subsequent transmission of data transmitted in the combined data and control information message.

The subsequent transmission utilizes frequency resources that may be the same as those used for transmission of the combined data and control information message.

The data portion of the combined message may have a predefined length.

The method may further comprise the step of populating the data for transmission to match the predefined length.

The predefined length may be selected from a plurality of predefined lengths.

The base station may transmit the combined control and data information message for the UE over a subset of the resources in the allocated resource region.

A subset of the resources may be selected using predefined rules that are known to both the base station and the UE.

The rule may use at least one of a UE ID, a slot number, a subframe number, and a size of the allocated resource region as input.

A method of receiving data received at a User Equipment (UE) from a base station in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the UE, receiving an indication of a resource region in the OFDM slot in which a combined data and control information message may be received; at the UE, receiving, in the allocated resource region, a data and control information message comprising a combination of a data portion and a control portion; and decoding the received combined data and control information message.

An indication of the allocated resource region may be received in an RRC message.

The combined data and control information message may include an indication of a resource in a data region of the OFDM slot on which a subsequent transmission of data transmitted in the combined data and control information message may be received.

The received subsequent transmission may be decoded with a demodulation reference signal (Demodulation Reference Signal, DMRS) that is used to decode the combined data and control transmission.

The data portion of the combined message may have a predefined length.

The predefined length may be selected from a plurality of predefined lengths.

A method of transmitting data from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at a base station, allocating a resource region in an OFDM slot for transmission of a data message, wherein the allocated resource region overlaps wholly or partially with a control region of the OFDM slot; transmitting an indication of the allocated resource region to the UE; and transmitting a message including data to the UE in the allocated resource region.

The indication of the allocated resource region may comprise information defining a transport format of the data message.

The indication of the allocated resource region may be sent in an RRC message.

The data message may include an indication of resources in a data region of the OFDM slot for subsequent transmission of data transmitted in the data message.

The data message may have a predefined length.

The predefined length may be selected from a plurality of predefined lengths.

The base station may send the data message to the UE over a subset of the resources in the allocated resource region.

A method of receiving data received at a User Equipment (UE) from a base station in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the UE, receiving an indication of a resource region in an OFDM slot in which a data message may be received, wherein the allocated resource region overlaps wholly or partially with a control region of the OFDM slot; receiving, at the UE, a data message in the allocated resource region; and decoding the received data message.

The data message may have a predefined length.

The predefined length may be selected from a plurality of predefined lengths.

The data message may be received over a subset of the resources in the allocated resource region.

The non-transitory computer readable medium may include at least one of the group consisting of: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, and flash memory.

Drawings

Further details, aspects and embodiments of the invention are described below, by way of example only, with reference to the accompanying drawings. For simplicity and clarity, elements in the figures have been shown and are not necessarily drawn to scale. The same reference numerals are included in the various figures to facilitate understanding.

Fig. 1 shows transmission resources in a conventional scheduling manner;

FIG. 2 shows a flow chart of a data transmission method; a kind of electronic device with high-pressure air-conditioning system

Fig. 3 shows the timing of the transmission.

Detailed Description

Those skilled in the art will recognize and appreciate that the specific details of the examples described are merely illustrative of some embodiments and that the teachings set forth herein are applicable in a variety of alternative configurations.

As described above, in the conventional system, a control message is transmitted to a control region of one frame to schedule subsequent transmission of data located in a data region of the frame (or the next frame). In addition to the scheduling information (time and frequency resources), the control message also includes parameters to be used for the transmission, such as modulation format, coding scheme, HARQ process number, precoding, etc., and detailed information about the resources of the ACK/NAK transmission on the uplink.

As set forth above, the UE is configured to listen to a PDCCH channel that includes control information on predefined CORESET resources. After receiving the DCI message on the PDCCH channel, the UE receives the PDSCH transmission on the indicated resources and decodes it using the provided parameters. Separate transmission of control information and data allows the base station to schedule these transmissions according to current network requirements and minimizes the resources that each UE needs to monitor (since each UE only needs to monitor the CORESET allocated for it in the DCI message, not all possible locations where the data is located).

Fig. 2 shows a method of transmitting control and data over a wireless link from a base station to a UE in a cellular communication network.

In step 20, the base station allocates a resource region in the time slot, which resource region can be used for transmission of a combined control and data message. Such a combined message includes both data transmitted to the UE and control information related to the data. The configuration of the resource region includes periodicity to repeat the region. Furthermore, the resource region may be located within the control region or may be independent. Thus, the allocated resources may be CORESET or other set of resources. With predefined rules known to both the base station and the UE, there is a set of possible resources in this area that can be used to send the combined control and data message. An exemplary rule is a rule defining allowed control resources (control channel elements) for transmitting PDCCH for a specific UE within CORESET, i.e. resources within the resource region may be selected in the same way as the resources used to transmit PDCCH are selected. Other rules may also be defined using one or more parameters (e.g., UE ID, slot number, etc.) that define the transmission opportunity for a particular UE within the resource region.

In step 21, the base station transmits an indication of the allocated resource region to the UE. For example, such a transmission may be an RRC message. The indication of this resource region may also include details that will typically be included in the control transmission defining the format of the subsequent data transmission, such as modulation format, coding scheme, HARQ process number, precoding, etc., as well as detailed information of the resources on the uplink related to the ACK/NAK transmission. Not all transmission details need to be defined within this indication message. Most of these transmission parameters are a priori to the base station and UE, for example by definition in the standard specification.

In step 22, upon receiving the indications of these resources, the UE configures itself to listen for messages sent with the indicated characteristics in the indicated resource region. In step 23, when data is ready to be transmitted, the base station uses the predefined parameters to transmit data in a message in the indicated resource region. This message is sent in a resource that may be located within a resource region configured according to the predefined rule that defines the transmission of the set of possible locations within the region. The message sent by the base station includes any control data required by the UE, and the data. That is, one combined control information and data message is transmitted in the configured area of the slot. One or more UE-specific parameters, namely UE ID or connection RNTI, may be used to identify rules for resources to be transmitted within the resource region. Some system parameters such as the size of the configured resource region, the slot number, the subframe number and the frame number may also be used. With this predefined rule, both the base station and the UE may determine one or more resource sets on which to send the combined control and data message to the UE. The advantage of using these parameters is that the set of transmission resources within the configured area is randomized for each UE and each transmission occasion. This mechanism may be similar to that used for conventional control transmissions (PDCCHs) to determine which resource sets may be used to send control information to a particular UE in a particular CORESET.

In step 24, the UE listens in the indicated resource region within the transmission possibilities defined by the known rule. The UE examines these all possible resource allocations within the configured resource region and receives and decodes the message to recover the data. The required data is thus sent to the UE in a single seal message (in the control region), thereby reducing delay. This reduces the overhead of control because many parameters previously sent for each message are either configured by the indication of the resource message or fixed to a specific value and therefore do not need to be retransmitted for each data transmission. And, since data is transmitted in a pre-configured resource region in a control message, scheduling information is not required, thereby further reducing overhead. Furthermore, this reduces CRC overhead. Traditionally, CRC bits are added to both control and data messages, but in this example only one set of CRC bits is needed, as there is only a single message.

The combined transmission allows for efficient use of demodulation reference symbols (demodulation reference symbol, DMRS) compared to separate control transmissions and separate data transmissions, so that better quality channel estimates can be prepared. Since the typical setup here is the transmission of small data packets with high reliability requirements, each transmission may require a certain density of DMRS in each transmission to ensure high quality channel estimation. For a given DMRS overhead, the combined transmission may be able to obtain better quality channel estimates due to even smaller combined control and data information. In other words, the combined transmission may reduce DMRS overhead compared to conventional control and data transmissions for a given quality of channel estimation.

In a variant of the method shown in fig. 2, the control and data messages in the control region may also comprise scheduling information for data transmission in the data region of the frame (or of a subsequent frame). This subsequent data transmission may be used for retransmission of data sent in the control region to improve transmission reliability. The overhead of control can be reduced by the pre-configuration and delay can be improved and quality of service can be improved since two transmissions of the data can be completed in a shorter time.

In another approach, if the data repetition transmission following the combined control and data transmission is scheduled on the same frequency resource, the UE may reuse the DMRS of the first combined transmission to obtain and improve the channel estimate for the data repetition (PDSCH) transmission. This may impose some restrictions on the antenna configuration for PDSCH transmissions. The antenna configuration (and the beamforming used if any) used to transmit PDSCH should be such that channel estimates can be derived from the channel estimates of the combined transmission.

The use of the transmission of the combined data and control information may increase the number of blind decodes that the UE has to perform. To limit the number of times blind decoding is performed, the transmission related parameters may be fixed in advance by this indication of resources, or only a subset of the possible options may be used to limit the number of tests that the UE has to perform.

In conventional systems, the UE listens to the preconfigured control resources to receive DCI messages indicating that data transmissions have been scheduled. In the search space within the control region, the UE must perform multiple blind decodes to find the PDCCH associated therewith. This multiple blind decoding is caused by the following factors:

there are multiple locations in the control resource that can be mapped to the PDCCH of a certain UE.

There are multiple aggregation levels associated with DCI, one of which the gNB may use to transmit the PDCCH.

The UE may be configured to listen to a plurality of different sizes of DCI.

Thus, for all the possibilities mentioned above, the UE needs to individually perform blind decoding for each different DCI size. For transmissions directed only to control messages, this is acceptable because the UE has preconfigured a set of DCIs that it should listen to in some control scenarios, so for most users they will know a limited set of DCI sizes they are configured to and can receive the corresponding DCIs. However, for the transmission of one combined control information and data information, the UE may not always be able to know the size of the data in advance. If the user has to perform multiple blind decoding, say to be compatible with the data length from N1 to N2, for example n1=10 bits and n2=60 bits, and each of the lengths belonging to integers falling within this range is a valid data size, a large blind decoding burden will result. In this case, there will be N2-N1 (50) blind decodes due to the length, which will also multiply the possible number of aggregation levels and their positions in the time-frequency resource. Thus, from the perspective of UE complexity, the blind decoding burden may soon make the combined transmission impractical.

To manage the number of blind decodes, a threshold may be defined for the size of data sent in the combined message. That is, the data portion of the combined message may be defined to be of a certain size. Furthermore, if the bits of the data are less than the threshold, the data may be packed with padding bits such that the number of bits is equal to the threshold. This enables the size of the data to be predefined and thus the UE has a priori knowledge about the data length to minimize the number of blind decoding tests. Although the transmission of padding or dummy bits somewhat reduces the advantages of the combined transmission, the reduction of the number of blind decodes may be more important to make the combined transmission scheme practical.

In one variation, a set of predefined data sizes may be defined to increase flexibility, but this may still limit the number of blind decodes required.

The opportunity for transmission of the combined data and control information may be network activated and may be done on a per UE basis. This technique is mainly applicable to URLLC type services in which the data is small and has strict delay requirements, so that transmission can be performed in the control area. The active operation on a per UE basis avoids the problem that the UE is unlikely to utilize this type of transmission to avoid the additional blind decoding burden.

Since most of the transmission parameters required to decode the combined transmission are fixed or configured for the UE as part of the configuration, the content of the control information in the combined control and data transmission may be very limited. In a variant of the proposed solution, all control parameters are either fixed to specific values, or the UE can determine them by a rule (e.g. using an equation), or pre-configured with a resource configuration so that the base station does not need to send any control information with the data. Thus, the combined transmission consists of only data transmitted to the UE in the configured resource region. In this way, data can be transmitted alone without any dynamic control parameters being transmitted. This would make these transmissions very resource efficient.

Fig. 3 shows the delay-reliability of a combined transmission compared to a conventional transmission in which a data transmission follows a control transmission. Fig. 3 (a) shows a conventional scheme, which configures one symbol of control resources, followed by 2 symbols for data transmission provided to the URLLC user. The URLLC packet arrives at the base station from the higher layer at 30. Tw represents the waiting time before the packet is scheduled. Tt represents the total transmission time, which includes control and data. This is followed by the UE processing time and the time to send HARQ ACK/NAK in UL direction, denoted as t_harq. A time equivalent to 2 symbols is adopted as t_harq. Assuming that the first transmission was unsuccessful and the UE sent a NAK, the gNB retransmits the same data packet after receiving the NAK from the UE. Thus, in the interval depicted in fig. 3 (a) as described above (an interval of 12 OFDM symbols with a certain designation), the gNB may send two data packets, i.e. one retransmission after the original transmission.

For equally long resource lengths, the target user is configured with resources that can transmit control and data in a single transmission, through a combined transmission as shown in fig. 3 (b). For the same number of HARQ processes and the same uplink transmission time of ACK/NAK, it can be observed that the base station can make 3 data transmissions, i.e. 2 retransmissions after the original transmission.

The combined control and data may improve the resource utilization of the small data packets. In addition, referring to fig. 3, there are two possible ways to utilize the combined transmission. If a certain reliability goal requires a certain number of retransmissions, the combined transmission provides advantages in terms of delay, which also means that in case of heavy transmission, the combined transmission can better accommodate the increased scheduling latency when the user cannot be served quickly. Another advantage may be in terms of reliability. If the channel conditions of the user are so poor that more retransmissions are needed within their delayed targets, the combined transmission will be able to make more retransmissions within a specific time interval than in conventional schemes. Thus, the combined transmission as a whole allows the network to have a greater percentage of users than in conventional schemes, meeting the required reliability and delay limits.

For ease of illustration, fig. 3 shows a transmission scenario consisting of control and data parts. NR allows simultaneous scheduling of time slot based data, non-time slot based data, and also allows the use of small time slots provided to different users. Similarly, NR allows the network to use different numerologies (numerology) with different durations and different frequency intervals. We do not describe in detail all the possibilities of such transmission, but the idea of combining control and data transmission is applicable to all configurations of such transmission.

The simulation results listed below show the potential impact of allowing transmission of combined control and data compared to scheduling a conventional transmission of data (PDSCH) through a transmission control (PDCCH).

A general transmission is to transmit control information DCI in PDCCH. The coding rate of the Polar code, which leads to a certain block error rate at a fixed SNR, has been calculated and then used to calculate how many coded bits to send. In these encoded bits, DMRS overhead of PDCCH is added, which is every 4 th PDCCH resource element in all resource blocks for PDCCH. The data transmission is also followed by a conventional PDSCH transmission with DMRS configuration type 1 for the first symbol, which is loaded with DMRS symbols preceding it, incurring 50% of the resource overhead. In these simulation results, 24-bit CRC is used for both control and data.

For the combined control and data transmission, the total information bits (combined data and control) are sent with the Polar codes and PDCCH DMRS on every 4 th resource element.

For conventional transmission the control information is taken to be 40 bits in size, whereas for the combined control and data transmission the control data is assumed to be 20 bits. This is because the combined transmission does not need to schedule any resources in terms of frequency PRBs and OFDM symbols. Similarly, the combined transmission does not require an MCS indication, but should have a limited number of possibilities, a set or fixed number, that need to be checked by blind decoding. Most importantly, the selection of HARQ, etc. also requires no or fewer bits than general DCI. As above, for the proposed method, the use of 20 bits to control the combined transmission is in fact passive, and in fact the control overhead of the combined transmission can easily be further reduced. An additional advantage of the payload (payload) that helps optimize the combined data and control is that there is a 24-bit CRC at a time.

If the transmission has to operate at a BLER of 10 (-N), this will be the BLER of the combined control and data transmission. On the other hand, for a conventional scheme with data scheduled by controlling transmission, to ensure this is a BLER of 10 (-N), the reliability of successful transmission is given by the following equation:

P＝P _c P _d

1-BLER＝(1-BLER _c )(1-BLER _d )

BLER＝BLER _c +BLER _d -BLER _c BLER _d

Due to BLER _c BLER _d Very small and therefore negligible, giving rise to:

BLER＝BLER _c +BLER _d

thus, to ensure that the BLER for a conventional transmission is 10 (-N), both control and data should operate at a BLER below 10 (-N), an exemplary point of operation may be that the control transmission and the data transmission are each 0.5X10 (-N).

Table 1 shows a comparison of the resources required to ensure a specific BLER value of 10 (-5) at snr= -5dB in two schemes, one of which is a conventional transmission scheme in which data (PDSCH) is followed by control information (PDCCH) transmission and the other of which is a combined transmission of control and data over the PDCCH. Each entry in the table shows the number of PRBs required to transmit a particular number of data information bits (shown at the top of each column) for a particular transmission scheme (the leftmost column shows various schemes). Typically, the allocation of PRBs is regular, so there is a granularity in the actual allocation, but for ease of illustration we show the minimum PRBs required without quantization. The channel model used for simulation and thereby the following comparison was TDL-A10 n-sec,3Km/h with antennas of 2 Tx and 2 Rx.

List one

The combined transmission transmits data in almost the same manner as the control information is transmitted with DMRS overhead of 1/4 (standardized for 5G NR PDCCH) in the conventional scheme. In the conventional method, the DMRS used is loaded in the front, i.e., in the first symbol. Thus, if only a single symbol data is used, DMRS overhead will become very large. For this reason, the resource usage pattern of the conventional scheme is shown as 3 different data lengths, i.e., 1, 2, and 4 OFDM symbols for carrying PDSCH. Since there is only one previously loaded (front-loaded) DMRS symbol, the DMRS overhead is maximum for a 1-symbol scheme and minimum for a 4-symbol scheme.

A comparison of the resource consumption shows that the combined transmission has advantages for a small number of information data packets. For 32 bits of information data, the combined transmission uses only 163 PRBs compared to 233 PRBs required for the conventional scheme using 4 data symbols. Conventional transmissions using 2 data symbols and 1 data symbol use 249 and 305 PRBs, respectively, making communication less efficient.

For this channel model and operational gist, the combined transmission and legacy scheme performs quite well with 200 bits of information data size, where 522 and 521 PRBs are used for both, respectively. Below this size, the combined transmission shows better performance and becomes more and more efficient as the size of the information data decreases.

Some of the advantages of the combined transmission of small packets come from the efficient channel coding of small packets. As with the conventional control transmission, since the combined transmission uses a transmission strategy including channel coding, it uses polar coding (polar coding). The polar coding for PDCCH in NR has performance advantage in case of using small data packet compared to LDPC, while the performance of LDPC is superior to polar coding for larger data packet. The proposed scheme is directed to smaller packets or data packets that use polarity encoding for combined control and data transmission, thus showing better results.

The above disclosure is mainly described by taking URLLC UEs as an example, but the disclosure may also be applicable to mass MTC devices. In most MTC devices, the amount of data transmission per device is small. In many cases, these data transmissions may also be periodic. Since the channel state information of these devices is not known at the base station because of the infrequent activity, the base station will typically select a fairly conservative transmission technique to communicate with these devices. Furthermore, most of these devices are inexpensive devices, and thus complex techniques may not be performed at all. 5G allows CORESET (resources for PDCCH) to be created anywhere in the slot, and a user may be configured to CORESET specific to multiple users. This will give the base station great flexibility, it may create a smaller CORESET for multiple groups of users (MTC devices) where the users may receive their control information or combined control and data without, for example, having a great impact on the capacity of the PDCCH. This is not possible in 4G LTE because it only transmits PDCCH in the first 2 or 3 symbols of one slot, and the capacity of PDCCH may soon become one choke point. With the disclosure presented herein, a base station may manage a large number of MTC devices with small data packets using a 5G flexible CORESET configuration.

It is understood from the context that references herein to transmission of "data" refer to "user data" carried to the UE on the downlink.

Although not shown in detail, any device or means forming part of the network may comprise at least a processor, a storage unit and a communication interface, wherein the processor unit, the storage unit and the communication interface are configured to perform the method of any aspect of the invention. Further options and choices are described below.

The signal processing functions of embodiments of the present invention, particularly the gNB and the UE, may be implemented using computing systems or architectures known to those skilled in the relevant art. Computing systems such as desktop, laptop or notebook computers, hand-held computing devices (PDAs, cell phones, palmtops, etc.), mainframes, servers, clients, or any other type of special or general purpose computing device as may be desired or appropriate for a given application or environment may be used. The computing system may include one or more processors, which may be implemented using a general-purpose or special-purpose processing engine, such as, for example, a microprocessor, microcontroller, or other control module.

The computing system may also include a main memory, such as Random Access Memory (RAM) or other dynamic memory, for storing instructions and information to be executed by the processor. Such main memory may also be used for storing temporary variables and other intermediate information to be executed by the processor during execution of instructions. The computing system may also include a Read Only Memory (ROM) or other static storage device for storing static information and instructions for the processor.

The computing system may also include an information storage system, which may include, for example, a media drive and a removable storage interface. The media drive may include a drive or other mechanism to support fixed or removable storage media, such as a hard disk drive, floppy disk drive, tape drive, optical disk drive, compact Disk (CD) or Digital Video Drive (DVD), read or write drive (R or RW), or other removable or fixed media drive. Storage media may include, for example, hard disk, floppy disk, magnetic tape, optical disk, CD or DVD, or other fixed or removable medium that is read by and written to by media drives. The storage medium may include a computer-readable storage medium having stored therein specific computer software or data.

In alternative embodiments, the information storage system may include other similar components for allowing computer programs or other instructions or data to be loaded into the computing system. Such components may include, for example, removable storage units and interfaces such as program cartridges and cartridge interfaces, removable memory (e.g., flash memory or other removable memory modules) and memory slots, and other removable storage units and interfaces that allow software and data to be transferred from the removable storage unit to the computing system.

The computing system may also include a communication interface. Such a communication interface may be used to allow software and data to be transferred between the computing system and external devices. Examples of communication interfaces may include modems, network interfaces (such as ethernet or other NIC cards), communication ports (such as, for example, universal Serial Bus (USB) ports), PCMCIA slots and cards, and so forth. Software and data transferred via the communications interface are in the form of signals which may be electronic, electromagnetic and optical or other signals capable of being received by the communications interface medium.

In this document, the terms "computer program product," "computer-readable medium," "non-transitory computer-readable medium," and the like may be used generally to refer to tangible media, such as memory, storage devices, or storage units. These and other forms of computer-readable media may store one or more instructions for use by a processor, including a computer system, to cause the processor to perform specified operations. Such instructions, generally referred to as "computer program code" (which may be grouped in the form of computer programs or other groupings), when executed, enable the computing system to perform functions of embodiments of the present invention. . Note that the code may directly cause the processor to perform specified operations, be compiled to do so, and/or be combined with other software, hardware, and/or firmware elements (e.g., libraries for performing standard functions) to do so

The non-transitory computer readable medium may include at least one of the group consisting of: hard disks, CD-ROMs, optical storage devices, magnetic storage devices, read-only memory, programmable read-only memory, erasable programmable read-only memory, EPROM, electrically erasable programmable read-only memory, and flash memory.

In embodiments where the elements are implemented using software, the software may be stored in a computer readable medium and loaded into a computing system using, for example, a removable storage drive. The control modules (in this example, software instructions or executable computer program code) when executed by a processor in a computer system cause the processor to perform the functions of the invention as described herein.

Furthermore, the inventive concept may be applied to any circuit for performing signal processing functions within a network element. It is further envisioned that a semiconductor manufacturer may utilize the inventive concepts in designing stand-alone devices such as Application Specific Integrated Circuits (ASICs) or microcontrollers of Digital Signal Processors (DSPs) and/or any other subsystem elements, for example.

It will be appreciated that the above description has described embodiments of the invention with reference to a single processing logic for clarity. However, the inventive concept may equally be implemented by a number of different functional units and processors to provide signal processing functionality. Thus, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization.

Aspects of the invention may be implemented in any suitable form including hardware, software, firmware or any combination of these. The invention may alternatively be implemented at least in part as computer software running on one or more data processors and/or digital signal processors or as a configurable module component such as an FPGA device. Thus, the elements and components of an embodiment of the invention may be physically, functionally and logically implemented in any suitable way. Indeed the functionality may be implemented in a single unit, in a plurality of units or as part of other functional units.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, while certain features have been described in connection with specific embodiments, those skilled in the art will recognize that different features of the described embodiments may be combined in accordance with the invention. In the claims, the term "comprising" does not exclude the presence of other elements or steps.

Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit or processor. Furthermore, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. Moreover, the inclusion of a feature in one category of claims does not imply a limitation to this category but rather indicates that the feature is equally applicable to other claim categories as appropriate.

Furthermore, the order of features in the claims does not imply any specific order in which the features must be performed and in particular the order of individual steps in a method claim does not imply that the steps must be performed in that order. Rather, the steps may be performed in any suitable order. Furthermore, singular references do not exclude a plurality. Thus, references to "a," "an," "the first," "the second," etc. do not exclude a plurality.

Although the present invention has been described in connection with some embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the scope of the invention is limited only by the appended claims. Furthermore, while certain features have been described in connection with specific embodiments, those skilled in the art will recognize that different features of the described embodiments may be combined in accordance with the invention. In the claims, the term "comprising" does not exclude the presence of other elements.

Claims

1. A method of transmitting data from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the base station, allocating a resource region in the OFDM slot for transmission of the combined data and control information message; transmitting an indication of the allocated resource region to the UE; and transmitting, in the allocated resource region, a combined data and control information message comprising the data portion and the control portion to the UE, wherein the combined data and control information message comprises an indication of resources in the data region of the OFDM slot for subsequent transmission of data transmitted in the combined data and control information message, wherein the base station transmits the combined control and data information message to the UE over a subset of the resources in the allocated resource region, wherein the subset of resources is selected using predefined rules known to both the base station and the UE.

2. The method of claim 1, wherein the indication of the allocated resource region comprises a periodicity according to which the resource region is repeated.

3. The method of claim 1, wherein the allocated resource region overlaps with the control region of the OFDM slot in whole or in part.

4. The method of claim 1, wherein the indication of the allocated resource region includes information defining a transport format of the combined data and control information message.

5. The method of claim 1, wherein the indication of the allocated resource region is sent in an RRC message.

6. The method of claim 1, wherein the subsequent transmission utilizes the same frequency resources as are used for transmission of the combined data and control information message.

7. The method of claim 1, wherein the data portion of the combined transmission has a predefined length.

8. The method of claim 7, further comprising the step of populating data for transmission to match the predefined length.

9. The method according to claim 7 or 8, wherein the predefined length is selected from a plurality of predefined lengths.

10. The method of claim 1, wherein the rule uses at least one of a UE ID, a slot number, a subframe number, and a size of the allocated resource region as input.

11. A method of receiving data transmitted from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the UE, receiving an indication of a resource region in the OFDM slot in which a combined data and control information message may be received; at the UE, receiving, in the allocated resource region, a data and control information message comprising a combination of a data portion and a control portion; and decoding the received combined data and control information message, wherein the combined data and control information message comprises an indication of resources in a data region of the OFDM slot over which a subsequent transmission of data transmitted in the combined data and control information message may be received, wherein the combined control and data information message is received over a subset of resources in the allocated resource region, wherein the subset of resources is selected using predefined rules known to both the base station and the UE.

12. The method of claim 11, wherein the indication of the allocated resource region comprises a periodicity according to which the resource region is repeated.

13. The method of claim 11, wherein the allocated resource region overlaps with the control region of the OFDM slot in whole or in part.

14. The method of claim 11, wherein the indication of the allocated resource region includes information defining a transport format of the combined data and control information message.

15. The method of claim 11, wherein the indication of the allocated resource region is received in an RRC message.

16. The method of claim 11, wherein the subsequent transmission utilizes the same frequency resources as are used for transmission of the combined data and control information message.

17. The method of claim 16, wherein the received subsequent transmission is decoded with a demodulation reference signal (Demodulation Reference Signal, DMRS) for decoding the combined data and control transmission.

18. The method of claim 11, wherein the data portion of the combined transmission has a predefined length.

19. The method of claim 18, wherein the predefined length is selected from a plurality of predefined lengths.

20. The method of claim 11, wherein the rule uses at least one of a UE ID, a slot number, a subframe number, and a size of the allocated resource region as input.

21. A method of transmitting data from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at a base station, allocating a resource region in an OFDM slot for transmission of a data message, wherein the allocated resource region overlaps wholly or partially with a control region of the OFDM slot; transmitting an indication of the allocated resource region to the UE; and transmitting, in the allocated resource region, a data message to the UE, wherein the data message comprises an indication of resources in the data region of the OFDM slot for subsequent transmission of data transmitted with the data message, wherein the base station transmits the data message to the UE over a subset of the resources in the allocated resource region, wherein the subset of resources is selected using a predefined rule known to both the base station and the UE.

22. The method of claim 21, wherein the indication of the allocated resource region comprises a periodicity according to which the resource region is repeated.

23. The method of claim 21, wherein the indication of the allocated resource region includes information defining a transport format of the data message.

24. The method of claim 21, wherein the indication of the allocated resource region is sent in an RRC message.

25. The method of claim 21, wherein the data message has a predefined length.

26. The method of claim 25, further comprising the step of populating data for transmission to match the predefined length.

27. The method according to claim 25 or 26, wherein the predefined length is selected from a plurality of predefined lengths.

28. The method of claim 21, wherein the rule uses at least one of a UE ID, a slot number, a subframe number, and a size of the allocated resource region as input.

29. A method of receiving data transmitted from a base station to a User Equipment (UE) in a wireless cellular communication network, the wireless link employing an orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexed, OFDM) transmission format, the method comprising the steps of: at the UE, receiving an indication of a resource region in an OFDM slot in which a data message may be received, wherein the allocated resource region overlaps wholly or partially with a control region of the OFDM slot; receiving, at the UE, a data message in the allocated resource region; and decoding the received data message, wherein the data message comprises an indication of resources in a data region of the OFDM slot for subsequent transmission of data transmitted with the data message, wherein the data message is received over a subset of the resources in the allocated resource region, wherein the subset of resources is selected using predefined rules known to both the base station and the UE.

30. The method of claim 29, wherein the indication of the allocated resource region comprises a periodicity according to which the resource region is repeated.

31. The method of claim 29, wherein the indication of the allocated resource region includes information defining a transport format of the data message.

32. The method of claim 29, wherein the indication of the allocated resource region is received in an RRC message.

33. The method of claim 29, wherein the data message has a predefined length.

34. The method of claim 33, wherein the predefined length is selected from a plurality of predefined lengths.

35. The method of claim 29, wherein the rule uses at least one of a UE ID, a slot number, a subframe number, and a size of the allocated resource region as input.