WO2018137567A1

WO2018137567A1 - Decoding method and apparatus for polar code

Info

Publication number: WO2018137567A1
Application number: PCT/CN2018/073417
Authority: WO
Inventors: 罗禾佳; 李榕; 张公正; 陈莹; 张华滋; 皇甫幼睿
Original assignee: 华为技术有限公司
Priority date: 2017-01-26
Filing date: 2018-01-19
Publication date: 2018-08-02
Also published as: CN108365848A; CN108365848B

Abstract

The present application discloses a decoding method and decoding apparatus for a polar code. The decoding method comprises: a terminal receiving a symbol sequence, wherein the symbol sequence is obtained by using a Polar code to encode control information and modulating and mapping same by a base station; the terminal demapping and demodulating the symbol sequence to obtain an encoded sequence; the terminal selecting two encoded sub-sequences from the encoded sequence; the terminal performing Polar decoding on the two encoded sub-sequences to obtain an information bit set, wherein the information bit set comprises downlink control information (DCI) and a cyclical redundancy check (CRC) sequence; and the terminal descrambling the CRC sequence using a terminal identifier and the terminal performing a CRC check on the DCI, and if the CRC check is passed, the DCI being obtained. By means of the decoding method, the number of times of blind detection for downlink control information is reduced by half.

Description

Method and device for decoding polar code

This application claims the priority of the Chinese Patent Application, filed on Jan. 26, 2017, filed Jan. In this application.

Technical field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for decoding a polar code.

Background technique

In the Long Term Evolution (LTE) system, the physical downlink control channel (English: Physical Downlink Control Channel, abbreviated as PDCCH) carries control information. The processing procedure of the PDCCH at the transmitting end is as shown in FIG. 1. The base station first performs a cyclic redundancy check (English: Cyclical Redundancy Check, abbreviated: CRC) on the downlink control information to be transmitted (English: Downlink Control Information, DCI) to obtain a 16-bit CRC sequence, and then the base station will 16 bits. RNTI (Chinese: Radio Network Temporary Identifier) information is XORed with a 16-bit CRC sequence (English: exclusive OR, abbreviation: XOR) operation (ie, scrambling operation), obtained by RNTI scrambling The 16-bit CRC sequence concatenates the 16-bit CRC sequence scrambled by the RNTI to the DCI described above, and performs channel coding, modulation, mapping, and transmission procedures. The PDCCH channel coding uses TBCC (English: Tailing bit convolution coding, Chinese: tail biting convolution coding).

As shown in FIG. 2, the receiving end does not know the specific time-frequency resource location of the PDCCH, and the receiving end needs to perform blind detection on the potential location of the PDCCH. Each time a blind check requires a channel decoding and CRC check, it can take up to several dozen times.

In the fifth-generation (5th generation, 5G) communication system and subsequent more possible communication systems, three types of scenarios are defined, namely enhanced mobile broadband (English: enhanced mobile broadband) (eMBB), ultra-reliable low-latency Communication (English: Ultra Reliable Low Latency Communications, URLLC) and large-scale Internet of Things (English: massive Machine Type Communications, abbreviation: mMTC). Among them, the eMBB service mainly includes ultra high definition video, augmented reality AR, virtual reality VR, etc. The main feature is that the transmission data volume is large and the transmission rate is high. The URLLC service is mainly used for industrial control and unmanned driving in the Internet of Things. The main features are ultra-high reliability, low latency, low transmission data and burstiness. The mMTC service is mainly used in smart grids and smart cities in the Internet of Things. The main features are the connection of massive devices, the small amount of data transmitted, and the delay of tolerating for a long time.

At the 87th meeting of 3GPP (English: 3rd Generation Partnership Project) RAN1 (English: Radio Access Network, Chinese: Radio Access Network), the polar Polar code was officially received as 5G eMBB. :enhanced Mobile Broadband) The channel coding scheme of the uplink and downlink control channels of the scenario. The polarity code is applied to the uplink and downlink control channels, and there is room for performance improvement in decoding.

Summary of the invention

In view of this, the main object of the present application is to provide a method and apparatus for decoding a polar code for improving the performance of polar code decoding.

In a first aspect, the present application provides a method for decoding a polar Polar code, which is applied to a wireless network. The method includes: receiving, by a terminal, a sequence of symbols, where the base station uses Polar code coding and modulation mapping for control information. Obtaining; the terminal demaps and demodulates the symbol sequence to obtain a coding sequence; the terminal selects two coding subsequences from the coding sequence; and the terminal performs a Polar translation on the two coding subsequences And obtaining a set of information bits, the set of information bits including downlink control information DCI and a cyclic redundancy check CRC sequence; the terminal descrambles the CRC sequence using a terminal identifier and the terminal performs CRC on the DCI Check, if the CRC check passes, DCI is obtained.

In a second aspect, the present application provides a decoding apparatus for a polar Polar code, which is applied to a wireless network, where the decoding apparatus includes: a receiving unit, configured to receive a symbol sequence, where the symbol sequence is used by a base station to control information. The Po code is encoded and modulated by the mapping; the processing unit is configured to perform de-mapping and demodulating the symbol sequence to obtain a coding sequence, and is further configured to select two coding sub-sequences from the coding sequence; Performing Polar decoding on the two coding subsequences to obtain an information bit set, where the information bit set includes downlink control information DCI and a cyclic redundancy check CRC sequence, and a descrambling unit, configured to use the terminal identifier to the CRC The sequence is descrambled; a check unit is configured to perform a CRC check on the DCI, and if the CRC check passes, a DCI is obtained.

In a third aspect, the present application provides a communication device, including: a memory for storing a program; a transceiver for receiving a sequence of symbols, the symbol sequence is a base station using Polar code encoding and modulation mapping for control information And obtaining, by the processor, the program for executing the memory storage, when the program is executed, the processor demaps and demodulates the symbol sequence to obtain a coding sequence; The coding sequence selects two coding subsequences; the processor performs Polar decoding on the two coding subsequences to obtain an information bit set, where the information bit set includes downlink control information DCI and cyclic redundancy check CRC. a sequence; the processor descrambles the CRC sequence using a terminal identifier and the terminal performs a CRC check on the DCI, and if the CRC check passes, a DCI is obtained.

In a fourth aspect, the present application provides a computer readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the decoding method as described in the first aspect.

With reference to all the above aspects, in a possible design, the terminal decodes the two coding sub-sequences to obtain a set of information bits, including: determining, by the terminal, a bit position and a value of the terminal identifier; The bit position and value of the terminal identification are used as input parameters for decoding.

In combination with all of the above, in one possible design, the bit position of the terminal identification includes the location of the CRC sequence and the location of the fixed set of bits.

In combination with all of the above, in one possible design, the bit position of the terminal identification includes the location of the CRC sequence and the location of the parity fixed bit set.

The present application reduces the number of blind detections of downlink control information by half by employing the above-described decoding method and apparatus and apparatus and computer readable storage medium.

DRAWINGS

FIG. 1 is a process of PDCCH processing at a transmitting end in LTE.

2 is a process of receiving PDCCH processing in LTE.

Figure 3 is a basic flow chart of wireless communication.

FIG. 4 is an application scenario diagram of an embodiment of the present application.

Figure 5 is a structural diagram of the Arikan Polar code.

Fig. 6 is a configuration diagram of a CA Polar code.

Fig. 7 is a configuration diagram of a PC Polar code.

FIG. 8 is a flowchart of a decoding method of the present application.

9 is a logical structural diagram of a decoding apparatus of the present application.

Figure 10 is a diagram showing the scrambling of the CA Polar code of the present application.

Figure 11 is a diagram showing the scrambling of the PC Polar code of the present application.

FIG. 12 is a first decoding diagram of a decoding method of the present application.

FIG. 13 is a second decoding diagram of a decoding method of the present application.

Figure 14 is a diagram showing the physical structure of a decoding apparatus of the present application.

detailed description

The specific embodiments of the present application are further described in detail below with reference to the accompanying drawings.

FIG. 3 is a basic flow of wireless communication. At the transmitting end, the source is sequentially sent after source coding, channel coding, rate matching, and modulation mapping. At the receiving end, the output sink is sequentially demodulated by demodulation, de-rate matching, channel decoding, and source decoding. The channel coding code can use a Polar code. Since the code length of the original Polar code (parent code) is an integer power of 2, in practical applications, a Polar code of arbitrary code length needs to be implemented by rate matching. The sender performs rate matching after channel coding to achieve an arbitrary target code length, and performs de-rate matching on the receiving end before channel decoding. It should be noted that the basic process of the wireless communication also includes additional processes (for example, precoding and interleaving), and since these additional processes are common common sense to those skilled in the art, they are not enumerated one by one. The CRC sequence and CRC information mentioned in this application are differently referred to as the same thing.

The embodiments of the present application can be applied to a wireless communication system, where a wireless communication system usually consists of a cell, each cell includes a base station (English: Base Station, BS for short), and the base station transmits to multiple mobile stations (English: Mobile Station, referred to as: MS) provides communication services in which the base station is connected to the core network device, as shown in FIG. The base station includes a BBU (English: Baseband Unit, Chinese: Baseband Unit) and an RRU (English: Remote Radio Unit). The BBU and the RRU can be placed in different places, for example, the RRU is pulled away, placed in an open area from high traffic, and the BBU is placed in the central computer room. BBUs and RRUs can also be placed in the same room. The BBU and RRU can also be different parts under one rack.

It should be noted that the wireless communication system mentioned in the embodiments of the present application includes, but is not limited to, a narrowband Internet of Things system (English: Narrow Band-Internet of Things, referred to as NB-IoT), and a global mobile communication system (English: Global System) For Mobile Communications (GSM), Enhanced Data Rate for GSM Evolution (EDGE), Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (English: Code Division Multiple Access, CDMA2000 for short), Time Division-Synchronization Code Division Multiple Access (TD-SCDMA), Long Term Evolution ( English: Long Term Evolution (LTE) and the three major application scenarios of next-generation 5G mobile communication systems, eMBB, URLLC and eMTC.

In the embodiment of the present application, the base station is a device deployed in a radio access network to provide a wireless communication function for the MS. The base station may include various forms of macro base stations, micro base stations (also referred to as small stations), relay stations, access points, and the like. In a system using different radio access technologies, the name of a device having a base station function may be different, for example, in an LTE system, an evolved Node B (evolved NodeB, eNB or eNodeB), in the third In the system (English: 3rd Generation, 3G for short), it is called Node B (English: Node B). For convenience of description, in all embodiments of the present application, the foregoing apparatus for providing wireless communication functions to the MS is collectively referred to as a base station or a BS.

The MSs involved in the embodiments of the present application may include various handheld devices having wireless communication functions, in-vehicle devices, wearable devices, computing devices, or other processing devices connected to a wireless modem. The MS may also be referred to as a terminal (English: Terminal), and may also include a subscriber unit (English: subscriber unit), a cellular phone (English: cellular phone), a smart phone (English: smart phone), a wireless data card, and a personal number. Assistant (English: Personal Digital Assistant, PDA for short) computer, tablet computer, wireless modem (English: modem), handheld device (English: handset), laptop (English: laptop computer), machine type communication (English) :Machine Type Communication, referred to as: MTC) terminal. For convenience of description, in all embodiments of the present application, the above-mentioned devices are collectively referred to as an MS.

The following is a brief introduction to the Polar code.

Communication systems usually use channel coding to improve the reliability of data transmission to ensure the quality of communication. The Polar code proposed by Turkish professor Arikan is the first code that theoretically proves to achieve Shannon capacity and has low coding and decoding complexity. The Polar code is also a linear block code whose encoding matrix is G _N and the encoding process is

among them

Is a binary line vector of length N (ie code length); G _N is an N × N matrix, and

Defined as the Kronecker product of log ₂ N matrices F ₂ . Above matrix

During the encoding of the Polar code,

A part of the bits are used to carry information, called a set of information bits, and the set of indexes of these bits is recorded as

The other part of the bit is set to a fixed value pre-agreed by the transceiver, which is called a fixed bit set or a frozen bit set.

Complement

Said. The encoding process of the Polar code is equivalent to:

Here, G _N (A) is the set of G _N

The sub-matrices obtained from those rows corresponding to the index, G _N (A ^C ) is the set of G _N

The sub-matrices obtained from those rows corresponding to the index.

for

The set of information bits in the quantity, K;

for

A fixed set of bits in the number (NK) that is a known bit. These fixed bits are usually set to 0, but the fixed bits can be arbitrarily set as long as the transceiver end pre-agreed. Thus, the encoded output of the Polar code can be simplified to:

Here

for

a collection of information bits,

a row vector of length K, ie

Represents the number of elements in the collection, K is the size of the information block,

Is the matrix G _N by the set

The submatrices obtained from the rows corresponding to the index,

Is a K × N matrix.

The construction process of the Polar code is a collection

The selection process determines the performance of the Polar code. The construction process of the Polar code is generally: determining that there are N polarized channels in total according to the length N of the mother code, respectively corresponding to N rows of the coding matrix, calculating the reliability of the polarized channel, and the first K polarizations with higher reliability. Channel index as a collection

Element, the index corresponding to the remaining (NK) polarized channels as the index set of fixed bits

Elements. set

Determine the location of the information bits, the collection

The position of the fixed bit is determined.

It can be seen from the coding matrix that the original Polar code (parent code) has a code length of 2, which is an integer power of 2, and in practice, a Polar code of arbitrary code length needs to be implemented by rate matching.

In order to improve the performance of the Polar code, the information bit set is first checked and precoded, and then Polar coded. There are two common types of check precoding, namely CRC (Chinese: Cyclic Redundancy Check) cascading Polar code, or PC (Chinese: Parity, English: Parity Check) Cascading Polar coding. Currently, Polar encoding includes: Airkan traditional Polar encoding and CA Polar encoding and PC Polar encoding.

For the Airkan traditional Polar coding description in Fig. 5, {u1, u2, u3, u5} is set as a fixed bit set, {u4, u6, u7, u8} is set as an information bit set, and 4 in the information vector of length 4 is set. The bit information bits are encoded into 8-bit coded bits.

For the CA Polar encoding in Fig. 6, {u1, u2} is set as a fixed bit set, {u3, u4, u5, u6} is set as a set of information bits, and {u7, u8} is a set of CRC bits. Among them, the value of {u7, u8} is obtained by CRC of {u3, u4, u5, u6}.

For CA Polar coding, a CA-SCL (English: CRC-Aided Successive Cancellation List) decoding algorithm is used. The CA-SCL decoding algorithm selects the path through which the CRC passes as the decoding output in the candidate path of the SCL decoding output by the CRC check.

For the PC Polar encoding in Fig. 7, {u1, u2, u5} is set as a fixed bit set, {u3, u4, u6, u7} is set as an information bit set, and {u7} is a PC fixed bit set. Among them, the value of {u7} is obtained by X0, u6} XOR.

For PC Polar coding, the decoding algorithm is based on the SCL decoding algorithm. The PC fixed bit set is used to complete the sorting and pruning process in the decoding process, and finally the most reliable path is output.

The present application provides a method for decoding a polar Polar code, which can be applied to a terminal device, for example, MS1-MS2 in FIG. Figure 8 is a flow chart of the decoding method, the specific steps are as follows:

Step 310: The terminal receives a symbol sequence, where the symbol sequence is obtained by the base station using the Polar code encoding and the modulation mapping.

Step 320: The terminal demaps and demodulates the symbol sequence to obtain a coding sequence.

Step 330: The terminal selects two coding subsequences from the coding sequence.

Step 340: The terminal performs Polar decoding on the two coding sub-sequences to obtain an information bit set, where the information bit set includes downlink control information DCI and a cyclic redundancy check CRC sequence.

Step 350: The terminal uses the terminal identifier to descramble the CRC sequence and the terminal performs a CRC check on the DCI. If the CRC check passes, the DCI is obtained.

It should be noted that the decoding apparatus 600 shown in FIG. 9 can implement the processes of receiving and decoding in steps 310-350. The receiving unit 610 is configured to perform step 310, the processing unit 620 is configured to perform

steps

320 and 330, the decoding unit 630 is configured to perform the decoding process of step 340, and the descrambling unit 640 is configured to perform the descrambling process in step 350. The verification unit 650 is configured to perform the verification process in step 350. The decoding device is, for example, a mobile station MS, and the decoding device may also be an application specific integrated circuit (ASIC) or a digital signal processor (English: Digital Signal Processor). DSP) or chip.

It should be noted that the control information in step 310 may be DCI, and the symbol sequence may be an OFDM (English: Orthogonal Frequency Division Multiplexing) symbol sequence. The coding sequence and the coding subsequence in step 330 are an LLR (English: Log Likelihood Ratio) sequence or an LLR subsequence. Moreover, in step 330, the terminal selects two coding subsequences from the coding sequence. Therefore, the two coding subsequences belong to the same aggregation level, that is, the lengths of the two coding subsequences after the solution rate matching are the same.

It should be noted that the terminal demaps and demodulates the symbol sequence to obtain an LLR sequence, and the terminal can only decode from the LLR subsequences of several potential symbol positions, wherein the LLR sub-sequence of the DCI at several potential symbol positions is also Called the search space, so steps 330-350 are also referred to as blind detection processes. Each time the blind check needs to complete the Polar decoding and CRC check, if the CRC check passes, the DCI is successfully obtained, the blind check process ends, and if the CRC check fails, the blind check is continued.

The step 340 specifically includes: determining, by the terminal, a bit position and a value of the terminal identifier; the terminal uses the bit position and the value of the terminal identifier as the input parameters of the decoding. The terminal identifier may be an RNTI, and the length of the RNTI is greater than or equal to 16 bits.

The bit position of the terminal identifier includes two possible implementation manners.

When Polar encoding uses CA Polar, the bit position of the terminal identification includes the location of the CRC sequence and the location of the fixed set of bits. As shown in Figure 10.

When the Polar code uses PC Polar, the bit position of the terminal identification includes the position of the CRC sequence and the position of the parity fixed bit set. As shown in Figure 11.

It should be added that the process of step 340 is as shown in FIG. Two LLR subsequences are used as inputs to the SCL decoder. When decoding the decoder, the decoding path is continuously extended. As can be seen from the figure, the decoder reserves 8 surviving paths. For PC Polar, the 8 surviving paths are sorted according to the path metric. The decoder finally The path with the smallest path metric is output, and the path with the smallest path metric (English: Path Metric, abbreviation: PM) is CRC checked. For CA Polar, the 8 surviving paths are sorted according to the path metric. The decoder outputs 8 surviving paths, and the CRC is checked according to the path metric from small to large, until the 8 surviving paths are not passed. Pass, return the surviving path with the smallest path metric.

It should be noted that the number of coding subsequences may be 4 or 8, as long as the number of coding subsequences does not exceed the width limit of the decoder.

Optionally, the decoding method may also use a ML (English: Maximum Likelihood) compensation decoder. Taking FIG. 13 as an example, when the number of extended paths reaches the upper limit L=8, pruning needs to be performed after expanding again, that is, 8 paths with better PMs are selected from the 32 paths as surviving paths. An ML compensation decoder shown in FIG. 13 performs ML decoding of an additional bit, that is, when the extended path grows to 16 lines, no pruning is performed, and then the first stage decoding is extended to 32 paths and then clipped. Branch, only 8 surviving paths are reserved.

It should be noted that, in the present application, the two LLR sub-sequences input by the decoder have different powers due to the difference of time-frequency resources, and the power difference between the two LLR sub-sequences may affect the decoding effect of the decoder. Therefore, before decoding, the LLR subsequence needs to be power balanced. For example, the vector of the first LLR subsequence is y1, the vector of the second LLR subsequence is y2, after the balance, y1'=y1, y2'=y2*sqrt(sum(y1^2)/sum( Y2^2)), then send y1' and y2' to the decoder for decoding.

As shown in FIG. 14, the present application also provides a communication device 900 that can be decoded. The communication device can be a decoding device or a DSP or ASIC or chip that implements the associated decoding function. The communication device 900 includes:

The memory 902 is configured to store a program, where the memory may be a RAM (English: Random Access Memory) or a ROM (English: Read Only Memory) or a flash memory, where the memory may be located. It may be located in the communication device alone or in the interior of the processor 903.

The transceiver 901 is configured to receive a sequence of symbols, where the base station obtains the control information by using a Polar code and modulates the mapping. The transceiver may be used as a separate chip, or may be a transceiver circuit in the processor 903 or As an input and output interface.

a processor 903, configured to execute the program stored by the memory, when the program is executed, the processor obtains a coded sequence by de-mapping and demodulating the symbol sequence; The coding sequence selects two coding subsequences; the processor performs Polar decoding on the two coding subsequences to obtain an information bit set, where the information bit set includes downlink control information DCI and cyclic redundancy check CRC sequence The processor uses the terminal identifier to descramble the CRC sequence and the terminal performs a CRC check on the DCI, and if the CRC check passes, the DCI is obtained.

The transceiver 901, the memory 902, and the processor 903 are connected by a bus 904.

It should be noted that the method performed by the processor is consistent with the foregoing, and details are not described herein.

In this embodiment, by using the coding and decoding features of the Polar code, two coding subsequences are input in the decoder, and the number of blind detections of the downlink control information is reduced by half by using the above decoding method.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in accordance with embodiments of the present application are generated in whole or in part. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be from a website site, computer, server or data center By wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL), or wireless (such as infrared, wireless, microwave, etc.) to another website, computer, server or data center transmission. The computer readable storage medium can be any available media that can be accessed by a computer or a data storage device such as a server, data center, or the like that includes one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD (Digital Video Disk), or a semiconductor medium (for example, a solid state hard disk). Solid State Disk, referred to as SSD).

Claims

A method for decoding a polar Polar code, which is applied to a wireless network, and includes:

The terminal receives a sequence of symbols, where the symbol sequence is obtained by the base station using the Polar code encoding of the control information and modulating the mapping;

Decoding and demodulating the symbol sequence to obtain a coding sequence;

The terminal selects two coding subsequences from the coding sequence;

Translating, by the terminal, the two coding sub-sequences to obtain an information bit set, where the information bit set includes downlink control information DCI and a cyclic redundancy check CRC sequence;

The terminal uses the terminal identifier to descramble the CRC sequence and the terminal performs a CRC check on the DCI. If the CRC check passes, the DCI is obtained.
The decoding method according to claim 1, wherein the terminal decodes the two coding subsequences to obtain a set of information bits, including:

Determining, by the terminal, a bit position and a value of the terminal identifier;

The terminal uses the bit position and value of the terminal identifier as input parameters for decoding.
The decoding method according to claim 2, wherein the bit position of the terminal identification includes a position of the CRC sequence and a position of the fixed bit set.
The decoding method according to claim 2, wherein the bit position of the terminal identification includes a position of a CRC sequence and a position of a parity fixed bit set.
A polar Polar code decoding device for use in a wireless network, comprising:

a receiving unit, configured to receive a symbol sequence, where the symbol sequence is obtained by using a Polar code and controlling the mapping information of the control information by the base station;

a processing unit, configured to perform de-mapping and demodulating the symbol sequence to obtain a coding sequence, and further configured to select two coding sub-sequences from the coding sequence;

a decoding unit, configured to perform wavelet decoding on the two coding sub-sequences to obtain an information bit set, where the information bit set includes downlink control information DCI and a cyclic redundancy check CRC sequence;

a descrambling unit, configured to descramble the CRC sequence by using a terminal identifier;

And a verification unit, configured to perform a CRC check on the DCI, and if the CRC check passes, obtain a DCI.
The decoding apparatus according to claim 5, wherein the decoding unit decodes the two coding subsequences to obtain a set of information bits, including:

Determining the bit position and value of the terminal identifier;

The bit position and value of the terminal identification are used as input parameters for decoding.
The decoding apparatus according to claim 6, wherein the bit position of the terminal identification includes a position of the CRC sequence and a position of the fixed bit set.
The decoding apparatus according to claim 6, wherein the bit position of the terminal identification includes a position of a CRC sequence and a position of a parity fixed bit set.
A communication device, comprising:

Memory for storing programs;

a transceiver, configured to receive a symbol sequence, where the symbol sequence is obtained by using a Polar code and controlling a mapping of the control information by the base station;

a processor, configured to execute the program stored by the memory, when the program is executed, the processor demaps and demodulates the symbol sequence to obtain a coded sequence; the processor from the code The sequence selects two coding subsequences; the processor performs Polar decoding on the two coding subsequences to obtain an information bit set, where the information bit set includes downlink control information DCI and cyclic redundancy check CRC sequence; The processor uses the terminal identifier to descramble the CRC sequence and the terminal performs a CRC check on the DCI. If the CRC check passes, the DCI is obtained.
A computer readable storage medium comprising instructions which, when executed on a computer, cause the computer to perform the decoding method of any of claims 1-4.