CN116155457A

CN116155457A - Method for adopting physical layer repeat transmission in 5G NR system

Info

Publication number: CN116155457A
Application number: CN202211607985.5A
Authority: CN
Inventors: 段红光; 刘世仟; 毛翔宇; 郑建宏; 罗一静
Original assignee: Chongqing University of Post and Telecommunications
Current assignee: Chongqing University of Post and Telecommunications
Priority date: 2022-12-14
Filing date: 2022-12-14
Publication date: 2023-05-23

Abstract

The invention relates to a method for adopting physical layer repeat transmission in a 5G NR system, which belongs to the technical field of mobile communication and comprises the following steps: for a data block to be transmitted, coding by adopting different channel redundancy coding modes at a transmitting end, forming two paths of independent data streams by adopting the same modulation mode, mapping multi-layer data to different logic ports by layer mapping, and respectively transmitting the data through different physical antenna ports; the receiving end receives wireless signals of different physical antenna ports from a wireless channel, and firstly, a demodulation reference signal is used for completing timing synchronization, channel estimation and channel equalization of received data; then obtaining layer mapping data through a signal detection method; the layer mapping data is subjected to de-layer mapping to obtain two different modulated data streams; two paths of different soft information are obtained through demodulation; and carrying out channel decoding on the two paths of different soft information by using two groups of different log likelihood values to obtain a transmission data block sent by a sending end.

Description

Method for adopting physical layer repeat transmission in 5G NR system

Technical Field

The invention belongs to the technical field of mobile communication, and relates to a method for adopting physical layer repeat transmission in a 5G NR system.

Background

The 3GPP defines three application scenarios of enhanced mobile broadband (Enhance Mobile Broadband, eMBB), mass internet of things communication (Massive Machine Type Communication, mctc), ultra high reliability and Ultra low latency services (URLLC)) for 5G.

Among other things, ultra-reliable low latency communication (URLLC) is a special use case of cellular communication, which includes a set of functions suitable for low latency and high reliability applications. Including mission critical applications such as industrial automation, autopilot, smart grid, intelligent transportation/freight, and augmented/virtual reality or telemedicine or industrial processes.

In the existing 3gpp 5g NR standard, the solution for high reliability is mainly achieved by retransmission, that is, PDCP retransmission (abbreviated PDCP), where the PDCP entity delivers duplicate PDCP PDUs to multiple RLC entities. The network can support four Copies (COPY) at most, and has the advantages of being capable of being configured and used in the existing certain architecture deployment scenarios (such as using CA or DC), and adopting a plurality of wireless link transmissions to solve the requirements on reliability and time delay in communication. Although repeated transmissions increase radio resource overhead and protocol complexity, in the course of repeated transmissions, once the transmission is correct, it indicates that the data block has been successfully transmitted, and the method is currently adopted by 3GPP and written into the specification. As shown in fig. 1, the retransmission mechanism of PDCP multiplexing in the current 5G NR system is shown.

When the radio resource control layer (RRC) configures duplicate transmissions for a radio bearer, at least one secondary RLC (RLC secondary) entity is added to the radio bearer to process duplicate PDCP PDUs, as shown in fig. 1, wherein the logical channel corresponding to the primary RLC (RLC primary) entity is referred to as a primary logical channel, the logical channel corresponding to the secondary RLC entity, and the secondary logical channel. All RLC entities have the same RLC mode. Therefore, the PDCP layer submits the same PDCP PDU to different RLC entities for multiple times to realize the transmission of the same data packet by multiple independent transmission paths, thereby improving the reliability of the transmission and reducing the delay and being beneficial to URLLC service.

When the retransmission is configured for a data radio bearer (abbreviated as DRB), the RRC layer (re) configures PDCP retransmission status (activated or deactivated). After configuration, the PDCP repeat transmission state may be dynamically controlled by a medium access control (abbreviated MAC) control element (abbreviated CE). And in the double link (abbreviated as DC), the terminal can be controlled using the MAC CE command regardless of its source (MCG or SCG).

When the repeated transmission is configured for signaling radio bearer (SRB for short), the repeated state is always in an active state, and dynamic control cannot be performed.

When the DRB configuration of more than one secondary RLC entity has repeated transmissions, the RRC also sets the state of each entity (i.e., activated or deactivated). The MAC CE may then be used to dynamically control whether the retransmission of each configured secondary (auxiliary) RLC entity of the DRB is active or inactive, i.e. which RLC entity is used for the retransmission. But the primary RLC entity cannot be disabled.

When the repeated transmission of a DRB is disabled, all secondary RLC entities associated with that DRB will be disabled. When the secondary RLC entity is deactivated, it is not re-established, the HARQ buffer is not flushed, and the transmitting PDCP entity should indicate to the secondary RLC body to discard all duplicate transmission PDCP PDUs.

When the DRB retransmission is activated, the new generation radio access network (briefly: NG-RAN) ensures that there is at least one active serving cell for each logical channel associated with the active RLC entity of the DRB; and when the serving cell is deactivated, the NG-RAN ensures that the duplication of the RLC entity associated with the logical channel will also be deactivated when the serving cell is not activated for the logical channel of the DRB.

When the duplicate transmission is active, the original PDCP PDU and the corresponding duplicate must not be transmitted on the same carrier. The logical channels configured with duplicate radio bearers may belong to the same MAC entity (called CA retransmission) or to different MAC entities (also called DC retransmission). When more than two RLC entities are configured for a radio bearer, CA retransmissions may also be configured in one or two MAC entities together with DC retransmissions. In the CA retransmission mode, the MAC entity is restricted from using logical channel mapping to ensure that different logical channels of the radio bearer in the MAC entity are not transmitted on the same carrier. When configuring CA retransmission for an SRB, one of the logical channels associated with the SRB is mapped to a primary cell or a primary secondary cell (PCell or PSCell, abbreviated as SpCell).

When the RLC entity confirms that the PDCP PDU transmission is successful, the PDCP entity should instruct other RLC entities to discard it. Furthermore, in the case of CA retransmission, when the RLC entity limited to only the secondary cell (abbreviated as SCell) reaches the maximum number of retransmissions of PDCP PDUs, the UE informs the base station (abbreviated as gNB) but does not trigger a radio link failure (abbreviated as RLF).

From the above description, in the PDCP repeat transmission function of the current 5G NR, it is required that the repeat transmission data block must use a different radio transmission path to ensure transmission reliability, and the success rate of radio link transmission can be increased. But this approach cannot achieve the diversity transmission effect, that is, in the physical layer transmission process, whether adopting the DC or CA repeat transmission method, it is independent on the physical layer link, and has no diversity transmission gain effect, which is much more difficult and complex than single carrier in deployment.

Disclosure of Invention

In view of the above, an object of the present invention is to provide a diversity combining method for signal transmission over the air.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a method for employing physical layer retransmission in a 5G NR system, comprising:

for a data block to be transmitted, coding by adopting different channel redundancy coding modes at a transmitting end, and forming two independent data streams by adopting the same modulation mode; mapping the two paths of data streams into multi-layer data through layer mapping; mapping the layer data to different logic ports, so that the data of the different logic ports are sent out through different physical antenna ports;

the receiving end receives wireless signals of different physical antenna ports from a wireless channel, and firstly, a demodulation reference signal is used for completing timing synchronization, channel estimation and channel equalization of received data; then obtaining layer mapping data through a signal detection method; the layer mapping data is subjected to a layer mapping process to obtain two different modulation data streams; two paths of different soft information are obtained through demodulation; and carrying out channel decoding on the two paths of different soft information by using two groups of different log likelihood values to obtain a transmission data block sent by a sending end.

Further, the data processing steps of the transmitting end are specifically as follows:

step A1: the physical layer receives a transport block of transport data from a higher layer protocol;

step A2: the physical layer carries out channel coding of different redundancy versions on the transmission data blocks to form two coded data blocks CodedBLock1 and CodedBLock2;

step A3: the physical layer carries out modulation processing on the coding blocks CodedLock 1 and CodedLock 2 to form two blocks of modulation symbol data ModulatordBlock 1 and ModulatordBlock 2;

step A4: performing layer mapping operation on the ModulatordBlock 1 and ModulatordBlock 2 data, and mapping the data into N-layer data LayerData1, layerData2 and …, layerDataN, wherein N is more than or equal to 2;

step A5: mapping the layer data to different logic antenna ports through precoding, and then mapping the layer data together with logic antenna port reference signals to time-frequency resources of Orthogonal Frequency Division Multiplexing (OFDM);

step A6: OFDM data for logical antenna ports is transmitted over the air through different physical antennas.

Further, in step A1, the physical layer receives a single transport block from the higher layer protocol

And the transport block adopts double-codeword transmission, two transmission parameters are the same, a cyclic check code is added behind the transport block, and the cyclic check with the length of 24 bits or 16 bits is adopted according to the size of the transport block to form the transport block with the same transport block as the transport block2.

Further, the step A3 specifically includes the following steps:

a31: performing the same rate matching, coding block cascading and scrambling operation on the coding data blocks of the codedBLock1 and the codedBLock2 to respectively generate a ScrambleBlock1 and a ScrambleBlock2 correspondingly;

a32: quadrature amplitude modulation is performed on the scrimbleblock 1 and the scrimbleblock 2 to form ModulatoredBlock 1 and ModulatoredBlock 2 modulation symbol data of two code words.

In step A5, the N-layer data is mapped into N logical ports, a one-to-one mapping method is adopted, and then, together with the reference signal DMRS of the logical ports, the 5G NR time domain signal is obtained through inverse fast fourier transform IFFT.

Further, in step A6, one logical antenna port is mapped to one independent physical antenna, and different physical antennas are located in different geographical locations.

Further, the data processing steps of the receiving end are specifically as follows:

step B1: the receiving end receives OFDM data sent by the sending end from the air, and the number of receiving antennas of the receiving end is larger than the number of logical antenna ports used by the sending end;

step B2: performing OFDM symbol timing synchronization, channel estimation and channel equalization processes through demodulation reference signals in OFDM symbols;

step B3: detecting the channel to obtain the time-frequency resource corresponding to each logic port, and taking out the time-frequency resource data corresponding to each logic port from each logic port;

step B4: performing logical port pre-coding decoding on the logical port time-frequency resource data to obtain layer data LayerData1, layerData2, … and LayerDataN;

step B5: performing de-layer mapping operation on the layer data to obtain two modulated data ModulatoredBlock 1 and ModulatoredBlock 2;

step B6: demodulating the modulated data ModulaedBlock 1 and ModulaedBlock 2 to obtain soft information llrBlock1 and llrBlock2;

step B7: and simultaneously sending the soft information of the llrBlock1 and the soft information of the llrBlock2 into channel decoding for decoding to obtain a transmission data block TransportBlock sent by a sending end.

Further, the step B6 specifically includes: descrambling the moduledBlock 1 and the moduledBlock 2 to obtain CodBLock 1 and CodBLock 2 data blocks, and then carrying out quadrature amplitude demodulation on the CodBLock 1 and the CodBLock 2 to obtain log likelihood values llrBlock1 and llrBlock2 of the two data blocks.

Further, the step B7 specifically includes: simultaneously carrying out joint LDPC decoding on the soft information of the llrBlock1 and the soft information of the llrBlock2 to obtain a transmission data block TransportBlock; and carrying out loop verification on the transport block, and if the loop verification is correct, submitting the correct transport data block transport block to a higher-layer protocol stack.

In the channel decoding described in step B7, the llrBlock1 is firstly adopted for decoding, and if the decoding is correct, the llrBlock2 is directly discarded; if the llrBlock1 is in decoding error, soft combining is carried out with the received llrBlock2, the decoding is carried out on the llrBlock1 continuously, and finally, the TransportBlock transport block is obtained through decoding.

In a mobile communication network, how to improve the communication reliability is always faced, especially in the application of the URLLC scenario in the 5G NR system, the 3GPP provides a solution for PDCP repeated transmission, namely, repeated transmission is adopted to improve the transmission accuracy, the method has two ways to perform repeated transmission, one adopts a multi-Carrier (CA) mode, repeated transmission blocks are repeatedly transmitted on different carriers, and the other adopts a double-link (DC) mode, and repeated transmission blocks are repeatedly transmitted on different access technologies. However, existing repeated transmissions require that both the network and the terminal support CA or DC, which is more difficult and complex to deploy than a single carrier.

Based on the above, the invention has the beneficial effects that:

first: the invention provides a method for repeating transmission in a physical layer, which can be used in a single carrier mobile communication system, reduces the requirements of equipment and spectrum resources, and does not need to adopt double links or multicarrier for realization.

Second,: in a mobile communication system, as the operating frequency increases, a Remote Radio Head (RRH) mode is being used in a large amount in order to provide coverage effect and coverage performance. The method can be used for repeating the transmission of the data block without adding a plurality of carriers, and the RRH mode is adopted to provide transmission gains from different directions.

Third,: in the existing PDCP repeated transmission method, the multiple repeated transmission combining gain cannot be obtained, but the method can carry out diversity combining processing on the data blocks which are repeatedly transmitted in different directions, which is equivalent to carrying out one retransmission at the same time in a physical layer, thereby greatly improving the transmission accuracy.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.

Drawings

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in the following preferred detail with reference to the accompanying drawings, in which:

FIG. 1 is a diagram of a PDCP repeat transmission mechanism defined by 3 GPP;

fig. 2 is a flow chart of the transmission and terminal reception of the 5G NR base station of the present invention;

fig. 3 is a flowchart of a base station transmitting PDSCH data according to an embodiment of the present invention;

fig. 4 is a flowchart of a terminal receiving PDSCH data according to an embodiment of the present invention;

fig. 5 is a mapping relationship diagram of PDSCH layer data, logical ports, and physical ports;

fig. 6 is a simulation diagram of 5G NR physical layer retransmission performance.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.

Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to limit the invention; for the purpose of better illustrating embodiments of the invention, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numbers in the drawings of embodiments of the invention correspond to the same or similar components; in the description of the present invention, it should be understood that, if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc., that indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but not for indicating or suggesting that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, so that the terms describing the positional relationship in the drawings are merely for exemplary illustration and should not be construed as limiting the present invention, and that the specific meaning of the above terms may be understood by those of ordinary skill in the art according to the specific circumstances.

In order to clearly illustrate the application of the present invention in an actual mobile communication system, the present invention provides an embodiment of adopting physical layer diversity repeat transmission, namely, in the existing fourth generation/fifth generation (4G/5G) mobile network, a higher layer protocol adopts a single codeword (abbreviated as one code) mode to send a data block, which is also called a physical layer transmission block (abbreviated as transport block), in the physical layer channel coding process, two different redundancy coding modes are adopted, double codeword data is formed through signal modulation, the double codeword data is mapped to different layers independently by layer mapping, the layer data is mapped to different antenna ports, and finally, the layer data is sent out through different physical antennas. At the receiving end, channel timing synchronization, channel estimation and equalization are completed, signal detection is carried out on the received data, two layers of data are obtained through de-layer mapping, each layer of modulated data is respectively demodulated, and soft information of the two layers of data, namely log likelihood values (LLR for short) are obtained. And simultaneously sending the two sets of received data LLRs to a channel decoder for decoding to obtain a transmission data block TransportBlock sent by a final sending end. As shown in fig. 2. In the present embodiment, if the processing is the same as the existing 3GPP, a reference protocol is directly given, and the present embodiment will not be described in detail.

In the case of the present embodiment, two processes of transmitting Physical Downlink Shared Channel (PDSCH) data by a 5G NR base station and receiving PDSCH data by a terminal are adopted

In this embodiment, the flow of PDSCH data transmitted by the base station is as follows:

step 1: the physical layer receives a single transmission data block (for short, a transport block) from a higher layer protocol, adopts double-codeword transmission, has the same two transmission parameters, adds a cyclic check code behind the transport block, and adopts 24-bit or 16-bit cyclic check according to the size of the transport block. With specific reference to section 7.2.1 in 3gpp ts 38.212. The physical layer repeatedly transmits the TransportBlock data block by adopting the method of the invention to form the same transport block of TransportBlock1 and TransportBlock 2. As in step 1 of fig. 3.

Step 2: the physical layer carries out low-density parity check code (LDPC) channel coding on the transport block1 and the transport block2 by adopting different redundancy versions to obtain two groups of coded channel coding data blocks CodedBLock1 and CodedBLock2 after coding. With specific reference to sections 7.2.2, 7.2.3 and 7.2.4 in 3gpp ts 38.212. The coding system bits of the CodedBlock1 and the CodedBlock2 are the same according to the method of the invention, and only the redundancy bits are different. As in step 2 of fig. 3.

Step 3: and performing the same rate matching, coding block cascading and scrambling operation on the coding data blocks of the CodedBlock1 and the CodedBlock2, and finally generating the corresponding codes of the ScrambleBlock1 and the ScrambleBlock2. Wherein rate matching, coding block concatenation is described with specific reference to sections 7.2.5, 7.2.6 in 3gpp ts 38.212; scrambling operations are described in section 7.3.1.1 of 3gpp ts 38.211. As in step 3 of fig. 3.

Step 4: the signals of the same mode are modulated by the Scramble Block1 and the Scramble Block2, and in this embodiment, a quadrature amplitude (16 QAM) modulation mode is adopted to form ModulatoredBlock 1 and Modaledblock 2 modulation symbol data of two codewords. With specific reference to section 7.3.1.2 in 3gpp ts 38.211. As in step 4 of fig. 3.

Step 5: and mapping the two codeword data into N (N is more than or equal to 2) layer data by adopting layer mapping, and recording as LayerData. In this embodiment, a2 codeword mapping 6-layer method is used, i.e., mapping into 6-layer data. With specific reference to section 7.3.1.3 in 3gpp ts 38.211. As in step 5 of fig. 3.

Step 6: the data of the layer 6 LayerData layer is mapped to different logic ports for transmission, and in the embodiment, 6 logic ports are adopted for transmission. With specific reference to sections 7.3.1.4, 7.3.1.5 and 7.3.1.6 in 3gpp ts 38.211. As in step 6 of fig. 3.

Step 7: different logical ports are mapped to different physical layer antenna ports for transmission into the air, in this embodiment one logical antenna port is mapped to one independent physical antenna and different physical antennas are in different geographical locations. As in step 7 of fig. 3.

In this embodiment, the processing flow of receiving PDSCH data by the terminal is as follows:

step 1: the receiving end receives the aerial signal, and obtains 6 layers of modulation data LayerData through Automatic Gain Control (AGC) adjustment, timing synchronization, channel estimation and equalization and signal detection. As in step 1 of fig. 4.

Step 2: in this embodiment, a2 codeword mapping 6-layer method is adopted, and a de-layer mapping operation is performed on the received 6-layer LayerData to obtain channel modulation data moduledblock 1 and moduledblock 2. With specific reference to section 7.3.1.3 in 3gpp ts 38.211. As in step 2 of fig. 4.

Step 3: descrambling is performed on moduledBlock 1 and moduledBlock 2 to obtain CodBLock 1 and CodBLock 2 data blocks, and then demodulation operation is performed on CodBLock 1 and CodBLock 2, in this embodiment, a 16QAM demodulation mode is adopted to obtain log likelihood values llrBlock1 and llrBlock2 of the two data blocks. With specific reference to section 7.3.1.2 in 3gpp ts 38.211. Remarks: scrambling is done by bit manipulation at the transmitting end, but descrambling is done by symbol manipulation at the receiving end. As in step 3 of fig. 4.

Step 4: and simultaneously carrying out joint LDPC decoding on the soft information of the llrBlock1 and the soft information of the llrBlock2 to obtain a transmission data block TransportBlock. With specific reference to section 7.2.4 in 3gpp ts 38.212. As in step 4 of fig. 4.

In channel decoding, the llrBlock1 is firstly adopted for decoding, and if the decoding is correct, the llrBlock2 is directly discarded. If the llrBlock1 is in decoding error, soft combining is carried out with the received llrBlock2, and the decoding of the llrBlock1 is continued. And finally, decoding to obtain a TransportBlock transport block.

Step 5: and carrying out loop verification on the transport block, and if the loop verification is correct, submitting the correct transport data block transport block to a higher-layer protocol stack. With specific reference to section 7.2.1 in 3gpp ts 38.212. As in step 5 of fig. 4.

In this embodiment, regarding layer mapping, logical port mapping and physical port mapping are described, as shown in fig. 5 in detail. In this embodiment, the transport block adopts a repeated transmission mode, so that two scrambled data blocks, namely, a scribmleblock 1 and a scrimbleblock 2, are obtained, and 6 layers of data are obtained through layer mapping, which are denoted as LayerData1, layerData2, and LayerData6. In the embodiment, the 6 layers of data are mapped to 6 logic ports, a one-to-one mapping method is adopted, then a 5G NR time domain signal is obtained through fast Fourier transform (IFFT) together with a logic port reference signal DMRS, and finally the 5G NR time domain signal is sent to the air through a physical antenna.

In this example, simulation verification was performed using a 5G Toolbox provided by Matlab 2022A version, in which one codon corresponds to 2 layers and two codons total to 4 layers, and simulation parameters are shown in table 1.

TABLE 1 physical layer repeat transmission simulation parameter configuration table

Simulation is performed by adopting a PDSCH link of 5G NR, and the simulation result is shown in figure 6. Wherein initial transmissionErrRatio represents the bit error rate of transmitting a transport block transmission data block only once in the simulation process; the phyDuplicaton ErrRatio indicates the bit error rate when the physical layer is adopted to enable repeated transmission, and only the bit error rate of the repeated transmission block is counted; transmisionErrRatio represents the bit error rate of two transport blocks when the physical layer is counted for repeated transmission; the phyCombineErrRatio represents the bit error rate when the physical layer is transmitting repeatedly, and only the bit error rate after the combination of the transmission block and the repeated transmission is counted. As shown in table 2.

Table 2 error rates under various simulation conditions

In fig. 6, 4 simulation cases are shown in comparison in initiaand computer errratio for ease of analysis. It is clear that phyCombine has about 3db to 4db higher performance than initial transmission. The method of the invention can provide the accuracy of the transmission block required to be sent by the high-layer protocol stack by adopting the physical layer retransmission transmission method under the condition of sacrificing the wireless resource.

Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the claims of the present invention.

Claims

1. A method for adopting physical layer repeat transmission in a 5G NR system is characterized in that: comprising the following steps:

2. The method for using physical layer retransmission in a 5G NR system according to claim 1, wherein: the data processing steps of the transmitting end are as follows:

3. The method for using physical layer retransmission in a 5G NR system according to claim 2, wherein: in step A1, the physical layer receives a single transport block from a higher layer protocol, adopts dual codeword transmission, has the same two transmission parameters, adds a cyclic check code behind the transport block, and adopts 24-bit or 16-bit cyclic check according to the size of the transport block to form transport block1 and transport block2 which are the same.

4. The method for using physical layer retransmission in a 5G NR system according to claim 2, wherein: the step A3 specifically comprises the following steps:

5. The method for using physical layer retransmission in a 5G NR system according to claim 2, wherein: in step A5, the N-layer data is mapped into N logical ports, a one-to-one mapping method is adopted, and then, together with the reference signal DMRS of the logical ports, the 5G NR time domain signal is obtained through inverse fast fourier transform IFFT.

6. The method for using physical layer retransmission in a 5G NR system according to claim 2, wherein: in step A6, one logical antenna port is mapped to one independent physical antenna, and different physical antennas are in different geographic locations.

7. The method for adopting physical layer retransmission in a 5G NR system according to any one of claims 2-6, wherein: the data processing steps of the receiving end are as follows:

8. The method for using physical layer retransmission in a 5G NR system according to claim 7, wherein: the step B6 specifically comprises the following steps: descrambling the moduledBlock 1 and the moduledBlock 2 to obtain CodBLock 1 and CodBLock 2 data blocks, and then carrying out quadrature amplitude demodulation on the CodBLock 1 and the CodBLock 2 to obtain log likelihood values llrBlock1 and llrBlock2 of the two data blocks.

9. The method for using physical layer retransmission in a 5G NR system according to claim 7, wherein: the step B7 specifically comprises the following steps: simultaneously carrying out joint LDPC decoding on the soft information of the llrBlock1 and the soft information of the llrBlock2 to obtain a transmission data block TransportBlock; and carrying out loop verification on the transport block, and if the loop verification is correct, submitting the correct transport data block transport block to a higher-layer protocol stack.

10. The method for using physical layer retransmission in a 5G NR system according to claim 9, wherein: in the channel decoding described in step B7, the llrBlock1 is firstly adopted for decoding, and if the decoding is correct, the llrBlock2 is directly discarded; if the llrBlock1 is in decoding error, soft combining is carried out with the received llrBlock2, the decoding is carried out on the llrBlock1 continuously, and finally, the TransportBlock transport block is obtained through decoding.