Method, apparatus, user equipment, base station and system for data transmission

Abstract

The application provides a data transmission method, device, user equipment, base station and system. The method is applied to user equipment in the coverage of a base station. There are multiple groups of user equipment in the coverage of the base station. The method comprises obtaining uplink resource information corresponding to a group to which the user equipment belongs. The uplink resource information comprises the frequency of L subcarriers used for uplink communication and the position information of n OFDM symbols corresponding to the group on a single subcarrier. The tree code encoder is used to encode the to-be-sent data and the check data, so as to obtain L groups of encoded data. Each group of encoded data in the L groups of encoded data is compressed into a code word with a length of n by using a compression matrix. The L groups of code words are subjected to OFDM modulation. After modulation, each group of code words with the length of n occupies one subcarrier in the L subcarriers, and each code word corresponds to one of the n OFDM symbols on the occupied subcarrier. The modulated data is sent. The uplink communication without random access can be realized.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a method, apparatus, user equipment, base station, and system for data transmission. Background Technology

[0002] Existing RACH-based and grant-based communication technologies, widely used in mobile broadband, require dedicated random access channels for user equipment (UEs) to perform the random access process and request base station resource scheduling via uplink control channels. Considering the massive number of UEs and sporadic data uplink demands in massive machine-type communication (mMTC) applications, existing RACH-based and grant-based communication technologies become unsuitable.

[0003] Existing standards define unlicensed communication as merely RACH-based grant-free, meaning user equipment still needs to go through a random access procedure for uplink synchronization. For low-cost, battery-powered IoT devices, the lack of a precise local clock and frequent need to enter sleep mode to conserve battery power result in a random access procedure accompanying every uplink transmission, representing a significant overhead. Therefore, eliminating the random access procedure and achieving unlicensed communication without random access has become a pressing issue. Summary of the Invention

[0004] This application provides a method, apparatus, user equipment, base station, and system for data transmission to achieve uplink communication without random access. The technical solution is as follows.

[0005] In a first aspect, a data transmission method is provided, the method being applied to any user equipment within the coverage area of ​​a base station, wherein there are multiple groups of user equipment within the coverage area of ​​the base station, the method comprising:

[0006] The user equipment obtains the uplink resource information corresponding to its packet. This uplink resource information includes the frequencies of L subcarriers used for uplink communication, and the position information of n OFDM symbols corresponding to the packet on a single subcarrier, where the n OFDM symbols are consecutive, and L and n are positive integers. The data to be transmitted and the check data are encoded using a tree-based code encoder to obtain L sets of encoded data. Each set of encoded data may include part of the data to be transmitted and part of the check data. This application does not limit the specific tree-based encoding method. Then, the J bits of data in this set are converted into a length of M=2 using position mapping. JThe data, here, is an array of length M elements, which is then compressed into codewords of length n using a compression matrix A. Each codeword of length n is a complex number. Then, Orthogonal Frequency Division Multiplexing (OFDM) modulation is performed on the L groups of codewords of length n. After modulation, each group of codewords of length n occupies one subcarrier out of the L subcarriers, and each codeword corresponds to one of the n OFDM symbols on its assigned subcarrier. Finally, the modulated data is transmitted to the base station.

[0007] The purpose of random access is to achieve uplink synchronization. Therefore, in the absence of random access, user equipment (UEs) suffers from uplink synchronization loss. Thus, to achieve random access-free operation, the impact of uplink synchronization loss needs to be addressed. Uplink synchronization loss is primarily caused by the frequency selection effect of the channel. Therefore, resolving the impact of uplink synchronization loss is equivalent to resolving the impact of the frequency selection effect. In this application, UEs within the base station coverage area are first grouped, and uplink resources are also grouped accordingly, with each group of UEs corresponding to a set of uplink resources. The data to be transmitted by the UEs is first divided into L parts using tree coding. Each part of the data is transmitted on multiple consecutive OFDM symbols of a subcarrier. Since a subcarrier belongs to a coherent channel, data transmitted within a coherent channel is largely unaffected by frequency selection effects. Therefore, each part of the data transmitted on a subcarrier is largely unaffected by frequency selection effects. This minimizes the impact of uplink synchronization loss, enabling uplink communication in a random access-free scenario.

[0008] In one possible implementation, the user equipment needs to establish downlink synchronization with the base station before acquiring uplink resource information.

[0009] In one possible implementation, after establishing downlink synchronization with the base station, the user equipment can decide whether to use unlicensed communication based on the amount of uplink data it needs. For example, when the uplink data volume is small, the user can choose to use unlicensed communication. Then, the user equipment can decide whether to use random access without authorization. If it does not use random access without authorization, it can perform a two-step random access process, sending a random access request to the base station and receiving a random access response from the base station.

[0010] In one possible implementation, if the user equipment chooses to use random access-free access, it can directly obtain the uplink resource information corresponding to its packet in the Broadcast Control Channel (BCCH). If the user chooses two-step random access, it can obtain the uplink resource information corresponding to its packet in the BCCH after completing the two-step random access.

[0011] In one possible implementation, the process of obtaining uplink resource information in BCCH can be as follows: based on the packet identifier (also known as the pre-packet radio network temporary identifier) ​​corresponding to the packet, multiple uplink resource information in BCCH are descrambled sequentially until the uplink resource information corresponding to the packet is obtained, wherein each uplink resource information corresponds to a user equipment of a packet.

[0012] In one possible implementation, the user equipment can also perform a complete random access process, that is, after receiving the random access response returned by the base station, it sends a scheduling transmission message to the base station and receives a conflict resolution message returned by the base station.

[0013] In one possible implementation, after completing full random access, the user equipment directly receives the uplink resource information corresponding to the packet sent by the base station through the downlink channel.

[0014] Secondly, a data transmission method is provided, the method being used in a base station, the base station coverage area including multiple user equipment packets, the method comprising:

[0015] The base station receives data transmitted by user equipment. It performs OFDM demodulation on the received data and outputs L first data sets corresponding to each of the multiple packets. Each first data set contains n*S elements, where L is the number of subcarriers used for uplink communication by the user equipment in the multiple packets, n is the number of OFDM symbols corresponding to each packet on a single subcarrier, and S is the number of receiving antennas of the base station. Sparse regression coding is performed on each first data set corresponding to each packet to obtain L second data sets corresponding to each packet, where the number of elements in each second set is greater than or equal to the number of user equipment in each packet. For each of the L second data sets corresponding to a packet, tree-structured coding is performed on the L second data sets corresponding to that packet to obtain the original data corresponding to that packet.

[0016] In the scheme shown in the embodiments of this application, the data to be transmitted is divided into multiple data parts on the user equipment side, and each data part carries multiple consecutive OFDM symbols transmitted in a subcarrier. Since the channels of different subcarriers are incoherent, the base station can use an incoherent demodulation method when performing sparse regression code decoding, because incoherent demodulation can demodulate (decode) the data without obtaining channel parameters.

[0017] In one possible implementation, incoherent demodulation can be maximum likelihood decoding.

[0018] In another possible implementation, noncoherent demodulation can be performed as iterative decoding of approximate information.

[0019] Both maximum likelihood decoding and approximate information iterative decoding are relatively mature decoding techniques, and their specific decoding processes will not be described in this application.

[0020] In one possible implementation, the base station can transmit multiple uplink resource messages via BCCH, where each uplink resource message corresponds to a user equipment in a packet. Each uplink resource message is scrambled using a packet identifier so that the user equipment can obtain the uplink resource message corresponding to its own packet based on its own packet identifier.

[0021] Thirdly, a data transmission apparatus is provided, the apparatus being applied to any user equipment within the coverage area of ​​a base station, wherein the base station coverage area contains multiple groups of user equipment, the apparatus comprising:

[0022] The acquisition module is used to acquire the uplink resource information corresponding to the group, wherein the uplink resource information includes the frequencies of L subcarriers used for uplink communication and the position information of n OFDM symbols corresponding to the group on a single subcarrier, wherein L and n are positive integers;

[0023] The tree code encoding module is used to encode the data to be sent and the verification data through the tree code encoder to obtain L sets of encoded data;

[0024] The compression module is used to compress each group of coded data in the L groups of coded data into a codeword of length n using a compression matrix;

[0025] The OFDM modulation module is used to perform orthogonal frequency division multiplexing OFDM modulation on L groups of codewords of length n. After modulation, each group of codewords of length n occupies one subcarrier among the L subcarriers, and each codeword corresponds to one OFDM symbol among the n OFDM symbols on the occupied subcarrier.

[0026] The transmitting module is used to transmit modulated data to the base station.

[0027] In one possible implementation, the device further includes a downlink synchronization module for:

[0028] Establish downlink synchronization with the base station.

[0029] In one possible implementation, the sending module is further configured to send a random access request to the base station;

[0030] The device further includes a receiving module for:

[0031] Receive the random access response returned by the base station.

[0032] In one possible implementation, the acquisition module is configured to:

[0033] Obtain the uplink resource information corresponding to the group in the Broadcast Control Channel (BCCH).

[0034] In one possible implementation, the acquisition module is configured to:

[0035] Based on the group identifier corresponding to the group, multiple uplink resource information in the BCCH are descrambled sequentially until the uplink resource information corresponding to the group is obtained. Each uplink resource information corresponds to a user equipment of a group.

[0036] In one possible implementation, the sending module is further configured to send a scheduling transmission message to the base station;

[0037] The receiving module is also used to receive conflict resolution messages sent by the base station.

[0038] In one possible implementation, the acquisition module is configured to:

[0039] Receive uplink resource information corresponding to the group to which the base station belongs.

[0040] Fourthly, a data transmission apparatus is provided, the apparatus being applied to a base station, the base station coverage area including multiple user equipment packets, the apparatus comprising:

[0041] The receiving module is used to receive data sent by the user equipment;

[0042] The OFDM demodulation module is used to perform OFDM demodulation on the data and output L first data sets corresponding to each of the multiple packets. Each first data set includes n*S elements, where L is the number of subcarriers used by the user equipment for uplink communication in the multiple packets, n is the number of OFDM symbols corresponding to each packet on a single subcarrier, and S is the number of receiving antennas of the base station.

[0043] The sparse regression code decoding module is used to perform sparse regression code decoding on each first data set corresponding to each group to obtain L second data sets corresponding to each group, wherein the number of elements in each second set is greater than or equal to the number of user devices in each group.

[0044] The tree code decoding module is used to perform tree code decoding on the L second data sets corresponding to each group to obtain the original data corresponding to the group.

[0045] In one possible implementation, the sparse regressive code decoding is used for:

[0046] Perform maximum likelihood decoding on each first data set corresponding to each group.

[0047] In one possible implementation, the sparse regression code decoding module is used for:

[0048] Approximate information is iteratively decoded for each first data set corresponding to each group.

[0049] In one possible implementation, the device further includes a transmitting module for:

[0050] Multiple uplink resource messages are sent via BCCH, with each uplink resource message corresponding to a user equipment in a packet.

[0051] Fifthly, a user equipment is provided, the user equipment including a processor and a memory, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor for data transmission as described in the first aspect above.

[0052] In a sixth aspect, a base station is provided, the base station including a processor and a memory, the memory storing at least one instruction, the at least one instruction being loaded and executed by the processor to implement the data transmission method as described in the second aspect above.

[0053] In a seventh aspect, a communication system is provided, the communication including the user equipment as described in the fifth aspect above and the base station as described in the sixth aspect above.

[0054] Eighthly, a computer-readable storage medium is provided, wherein a computer program is stored therein, the computer program being loaded and executed by a processor to implement the data transmission method as described in the first or second aspect above.

[0055] Ninthly, a computer program product is provided, the computer program product including a computer program stored in a computer-readable storage medium, the computer program being loaded and executed by a processor to implement the data transmission method as described in the first or second aspect above. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of a static access process provided in an embodiment of this application;

[0057] Figure 2 This is a schematic diagram of a semi-static access process provided in an embodiment of this application;

[0058] Figure 3 This is a schematic diagram of a semi-static access process provided in an embodiment of this application;

[0059] Figure 4 This is a schematic diagram of a dynamic access process provided in an embodiment of this application;

[0060] Figure 5 This is a flowchart of a data transmission method provided in an embodiment of this application;

[0061] Figure 6 This is a schematic diagram of an encoder provided in an embodiment of this application;

[0062] Figure 7 This is a flowchart of a data transmission method provided in an embodiment of this application;

[0063] Figure 8 This is a schematic diagram of a decoder provided in an embodiment of this application;

[0064] Figure 9 This is a schematic diagram of a data transmission device structure provided in an embodiment of this application;

[0065] Figure 10 This is a schematic diagram of a data transmission device structure provided in an embodiment of this application;

[0066] Figure 11 This is a schematic diagram of the structure of a user equipment provided in an embodiment of this application;

[0067] Figure 12 This is a schematic diagram of the structure of a base station provided in an embodiment of this application. Detailed Implementation

[0068] This application provides a data transmission method applicable to static access, semi-static access, and dynamic access scenarios for user equipment. Static access is also known as unauthorized access without random access, while dynamic access is known as unauthorized access without random access. In other words, the data transmission method provided in this application can achieve unauthorized access without random access.

[0069] These scenarios will be explained in detail below.

[0070] I. Static Access

[0071] Static access means no random access and no authorization required. See also Figure 1 This diagram illustrates a static access process. When there is no data transmission, the user equipment (UE) enters a sleep state to conserve battery power. When data transmission is available, it wakes up from sleep. Upon waking, downlink synchronization is performed first. Then, the corresponding uplink resource information is obtained directly from the broadcast control channel (BCCH). Uplink communication can then be performed based on this uplink resource information. After completing uplink data transmission, the UE re-enters sleep mode.

[0072] II. Semi-static Access

[0073] Semi-static access has the following two scenarios:

[0074] Scenario 1: Two-step random access without authorization

[0075] See Figure 2 This diagram illustrates a semi-static access process. When there is no data transmission, the user equipment (UE) enters a sleep state to conserve battery power. When data transmission is available, it wakes up from sleep. Upon waking, downlink synchronization is performed first. Then, it attempts to acquire the corresponding uplink resource information via the broadcast control channel. If acquisition fails, a random access procedure is initiated. Specifically, the UE sends a random access request (Msg 1) to the base station, which returns a random access response (Msg 2). Subsequently, the UE can acquire the corresponding uplink resource information via the broadcast control channel. Uplink communication can then be performed based on this information. After completing uplink data transmission, the UE re-enters sleep mode.

[0076] Scenario 2: Complete random access without authorization

[0077] See Figure 3This diagram illustrates a semi-static access process. When there is no data transmission, the user equipment (UE) enters a sleep state to conserve battery power. When data transmission is available, it wakes up from sleep. First, downlink synchronization is performed. Then, it attempts to acquire the corresponding uplink resource information via the broadcast control channel. If acquisition fails, a random access procedure is initiated. Specifically, the UE sends a random access request (Msg1) to the base station, which returns a random access response (Msg2). The UE then sends a scheduled transmission message (Msg3) to the base station to request uplink resources. The base station returns a conflict resolution message (Msg4). Subsequently, the base station sends uplink resource information to the UE. This uplink resource information can be sent via the downlink channel between the base station and the UE, or via the broadcast control channel. The UE can then perform uplink communication based on the uplink resource information. After completing uplink data transmission, the UE re-enters sleep mode.

[0078] III. Dynamic Access

[0079] Dynamic access is the standard authorized communication based on random access; see [link to relevant documentation]. Figure 4 This diagram illustrates a dynamic access process. When there is no data transmission, the user equipment (UE) enters a sleep state to conserve battery power. When data transmission is needed, it wakes up from sleep. Downlink synchronization is performed first. At this point, due to the large amount of data requiring uplink transmission, the UE determines that authorized communication based on random access is required and initiates the random access process. Specifically, the UE sends a random access request (Msg1) to the base station, the base station returns a random access response (Msg2), the UE sends a scheduled transmission message (Msg3) to the base station, and the base station returns a conflict resolution message (Msg4), thus achieving uplink synchronization for the UE. Then, the UE periodically sends scheduling requests to the base station, which returns uplink authorization messages, carrying uplink resource information for the UE's uplink transmission. After completing uplink data transmission, the UE re-enters sleep mode.

[0080] The following is combined Figure 5 The flowchart shown illustrates the data transmission method provided in the embodiments of this application:

[0081] Step 501: The user equipment obtains the uplink resource information corresponding to its group.

[0082] The uplink resource information includes the frequencies of the L subcarriers used for uplink communication, the location information of the n OFDM symbols corresponding to the user equipment packet on a single subcarrier, the structure information of the OFDM symbols, and the ratio of single-user bit energy to noise spectral density specified by the base station, where L and n are positive integers.

[0083] The structural information of OFDM includes T sym(Δf) and T CP Among them, T sym(Δf) This indicates that, with a subcarrier spacing of Δf, the time-domain length of a single OFDM symbol is T. sym(Δf) T CP This indicates the length of the cyclic prefix. For example, the structure information of OFDM is: T sym(15kHz) =66.67μs, T CP =16.67μs. This means that with a subcarrier spacing of 15kHz, the time domain length of a single OFDM symbol is 66.67μs, and the cyclic prefix length is 16.67μs. Furthermore, the cyclic prefix length must be no less than the sum of the delay caused by uplink synchronization failure at the user equipment and the delay caused by multipath effects of the user equipment itself.

[0084] The ratio of single-user bit energy to noise spectral density can be expressed as:

[0085]

[0086] Among them, E b N represents the bit energy of a single user. o This represents the noise spectral density for a single user.

[0087]

[0088] Where SNR represents the signal-to-noise ratio of a single user, and R represents the bit rate of a single user.

[0089]

[0090] Where B is the number of bits of information uploaded by a single user in a single instance, and n is the number of OFDM symbols corresponding to each user group on a single subcarrier.

[0091] In implementation, the base station can allocate a resource block for unlicensed uplink communication by user equipment. This resource block includes L subcarriers and Q subframes. Each subcarrier has N OFDM symbols, and each subframe includes N / Q OFDM symbols. The N OFDM symbols on each subcarrier are divided into G groups, with n = N / G symbols in each group. Correspondingly, the base station estimates the number of all potential user equipment and divides them into G groups, where G is an integer greater than 1. Each group corresponds to uplink resource information, which indicates the time-frequency domain resources used by the user equipment in the corresponding group for unlicensed uplink communication.

[0092] Table 1 below shows one possible grouping configuration for a given resource block. A resource block used for uplink communication of user equipment comprises 12 subcarriers and 10 subframes. Each group occupies 2 subframes of resources on one subcarrier. Taking a subframe containing 12 OFDM symbols as an example, each group occupies 24 OFDM symbols on one subcarrier.

[0093] Table 1

[0094]

[0095] In this context, SF1, SF2, SF3, SF4, SF5, SF6, SF7, SF8, SF9, and SF10 represent 10 subframes, l1, l2...l12 represent 12 subcarriers, and g1, g2, g3, g4, and g5 represent 5 packets.

[0096] The following describes the method by which user equipment obtains uplink resource information corresponding to its own group:

[0097] In static access scenarios:

[0098] Each group of user equipment corresponds to a pre-packet radio network temporary identifier, which can be 16 bits. For example, if the user equipment is divided into 5 groups, then the pre-packet radio network temporary identifiers corresponding to the five groups can be represented in hexadecimal as: 0xFFF0, 0xFFF1, 0xFFF2, 0xFFF3, and 0xFFF4, respectively.

[0099] The base station can periodically transmit G groups of uplink resource information through the broadcast control channel. Each group of uplink resource information is scrambled using a pre-packet radio network temporary identifier (PRTI). The G groups of uplink resource information are scrambled using G different pre-packet RTIs. The G pre-packet RTIs used for scrambling are the same as the G pre-packet RTIs corresponding to the user equipment in the aforementioned G groups.

[0100] After being woken up, the user equipment first performs downlink synchronization. After downlink synchronization is completed, the user equipment descrambles the G group uplink resource information in the broadcast control channel according to its corresponding pre-packet radio network temporary identifier until it obtains uplink resource information that can be successfully descrambled.

[0101] In a semi-static access scenario:

[0102] In the case of two-step random access:

[0103] After waking up, the user equipment (UE) first performs downlink synchronization. After downlink synchronization, the UE sequentially descrambles the G groups of uplink resource information in the broadcast control-to-broadcast control channel according to its corresponding initial pre-packet radio network temporary identifier (PRNAT). If descrambling fails, the UE sends a random access request (Msg1) to the base station, which returns a random access response (Msg2). The random access response carries G PRNATs used to scramble the uplink resource information. Upon receiving the random access response (Msg2), the UE randomly selects one of the G PRNATs to replace the initial PRNAT. Then, the UE uses the selected PRNAT to sequentially descramble the G groups of uplink resource information in the broadcast control-to-broadcast control channel until descrambling is successful and the corresponding uplink resource information is obtained.

[0104] II. In the case of complete random access:

[0105] After being woken up, the user equipment (UE) first performs downlink synchronization. After downlink synchronization, the UE descrambles the Group G uplink resource information in the broadcast control channel according to its corresponding initial pre-packet radio network temporary identifier (IPN). If descrambling fails, the UE sends a random access request (Msg1) to the base station, carrying the UE's identifier. The base station returns a random access response (Msg2). The UE then sends a scheduled transmission message (Msg3) to the base station to request uplink resources, and the base station returns a conflict resolution message (Msg4). Subsequently, the base station determines the target IPN corresponding to the UE based on its identifier and transmits the uplink resource information corresponding to the target IPN to the UE through the downlink channel between the base station and the UE.

[0106] In dynamic access scenarios:

[0107] After waking up, the user equipment (UE) first performs downlink synchronization. After downlink synchronization is complete, the UE sends a random access request (Msg1) to the base station, carrying the UE's identifier. The base station returns a random access response (Msg2). The UE then sends a scheduled transmission message (Msg3) to the base station, and the base station returns a conflict resolution message (Msg4). The UE then sends a scheduling request to the base station. The base station returns an uplink grant message, which carries uplink resource information for the UE's uplink transmission.

[0108] Step 502: The user equipment encodes the data to be sent and the verification data using a tree code encoder to obtain L sets of encoded data.

[0109] In implementation, the encoding process can be achieved by an encoder set in the user equipment. Specifically, the encoder may include, for example: Figure 6 The diagram shows a tree encoder, a mapper, a compressor, and an OFDM modulator.

[0110] The user equipment uses a tree-type code encoder to add verification data to the data to be sent and divides it into L parts.

[0111] For example, if the data to be transmitted is B bits and the checksum is P bits, a tree encoder is used to add P bits of checksum data to the B bits of data to be transmitted. The resulting data is then divided into L encoded data portions. Each encoded data portion contains J bits of data. That is, B, P, J, and L satisfy the following relationship:

[0112] B+P=L*J

[0113] Step 503: The user equipment compresses each group of encoded data in the L groups of encoded data into a codeword of length n.

[0114] In implementation, for each group of encoded data, the mapper converts the J bits of data in that group into a length of M=2 using position mapping. J The data, here, is an array of length M elements, which is then compressed into codewords of length n using a compression matrix A (a codeword of length n is n codewords, and each codeword is a complex number). symbol The complex number is represented by a compressed matrix consisting of n rows and M columns of complex numbers. The compressed matrix is ​​also called a codebook.

[0115] The process will be explained below using an example where each group of encoded data has J = 3 bits.

[0116] Table 2 below shows the various possible cases of 3-bit data (binary) with a length of M=2. 3 The data.

[0117] Table 2

[0118] Binary representation (3 bits) Decimal representation <![CDATA[Position mapping (length 2 3 )]]> 000 0 1 0 0 0 0 0 0 0 001 1 0 1 0 0 0 0 0 0 010 2 0 0 1 0 0 0 0 0 011 3 0 0 0 1 0 0 0 0 100 4 0 0 0 0 1 0 0 0 101 5 0 0 0 0 0 1 0 0 110 6 0 0 0 0 0 0 1 0 111 7 0 0 0 0 0 0 0 1

[0119] For each group of 3 bits of data, the corresponding length can be determined from Table 2 to be 2. 3 The data.

[0120] For example, if 3 bits of data are 001, then the corresponding length is 2. 3 The data is 0 1 0 0 0 0 0 0.

[0121] Then, the compressor passes through the compression matrix. Multiplying by the determined length is 2 3 From the data, we can obtain the n codewords corresponding to the 3 bits of data in that group.

[0122] For example, the determined length is 2 3 If the data is 0 1 0 0 0 0 0 0, then a compression matrix is ​​used. Multiply by (0 1 0 0 0 0 0 0) T We obtain the n elements in the second row of the compression matrix A, which are the n codewords corresponding to the 3-bit data in that group. Here, T is the transpose symbol.

[0123] Step 504: The user equipment performs OFDM modulation on L groups of codewords of length n.

[0124] In this configuration, each codeword of length n after modulation occupies one of the L subcarriers, and each codeword corresponds to one of the n OFDM symbols on the subcarrier it occupies.

[0125] In practice, for each group of codewords in the L groups, the user equipment performs OFDM modulation on the group of codewords and adds a cyclic prefix. After modulation, each group of codewords with a length of n occupies one of the L subcarriers, and each codeword corresponds to one of the n OFDM symbols on the occupied subcarrier.

[0126] Step 505: The user equipment sends the modulated data to the base station.

[0127] The decoding process on the base station side is explained below:

[0128] The base station is equipped with S antennas to receive uplink data from user equipment. After receiving the uplink data, the base station decodes it. For details, see [link to details]. Figure 7The decoding process may include the following steps:

[0129] Step 701: Receive data sent by the user equipment.

[0130] In practice, the base station can receive data transmitted by user equipment through its receiving antenna. The received data may be superimposed in the time and frequency domains, requiring appropriate processing to obtain the original data transmitted by the user equipment.

[0131] Step 702: Demodulate the received data using OFDM and output L sets of first data corresponding to each of the multiple packets.

[0132] Each first data set includes n*S elements, where L is the number of subcarriers used for uplink communication by the user equipment of the multiple groups, n is the number of OFDM symbols corresponding to each group on a single subcarrier, and S is the number of receiving antennas of the base station.

[0133] In practice, decoding can be performed by a decoder set up in the base station, specifically, as follows: Figure 8 As shown, the decoder may include: an orthogonal frequency division multiplexing demodulator (OFDM Demodulator), a sparse regression code decoder, and a tree code decoder.

[0134] The OFDM demodulator performs OFDM demodulation on the received data to remove the cyclic prefix. Then, based on the position of the OFDM symbol for each packet on each subcarrier, it performs the following decoding process on the data carried on each subcarrier.

[0135] The data transmitted by the user equipment in packet g carried on subcarrier l are arranged as follows: A matrix of the form (i.e., the first data set mentioned above). Here, subcarrier l is any one of the L subcarriers, and group g is any one of the G groups.

[0136] Thus, for group g, we can obtain L Y's. l，g That is, Y 1，g Y 2，g ...Y L，g .

[0137] Step 703: Decode each first data set corresponding to each group using sparse regression codes to obtain L second data sets corresponding to each group.

[0138] In this context, the number of elements in each second set is greater than or equal to the number of user devices in each group. The sparse regression code decoder can be an approximate message passing (AMP) decoder or a maximum likelihood (ML) decoder.

[0139] In implementation, base stations cannot accurately know the number of active users in the current group, but can only estimate a rough number. Furthermore, considering the characteristics of sparse regression code compressed sensing, to prevent missed detections, the sparse regression code decoder follows... To estimate the number of user devices within each group. K is the base station's estimate of the number of user equipment in group G. Δ The compensation value is a positive integer, for example, K. Δ It can be less than or equal to Positive integers.

[0140] Sparse regression code decoder for Y l，g Decode and output a value of size T g The list (i.e., the second data set) is denoted as:

[0141]

[0142] Thus, for group g, we can obtain the following L: Specifically:

[0143]

[0144] Step 704: For each group, perform tree-code decoding on the L second data sets corresponding to the group to obtain the original data corresponding to the group.

[0145] In implementation, the tree code decoder... Decode it.

[0146] The following example illustrates tree code decoding:

[0147] For example, L = 3, T g =4. For group 1, the following three lists can be output in step 703:

[0148]

[0149]

[0150]

[0151] First of all, with Decoding the tree code for the root node can be performed as follows:

[0152] I. If each element in the subfolder is treated as a leaf node, then the following four branches can be obtained:

[0153]

[0154]

[0155]

[0156]

[0157] two, Each element within the function can include a portion of validation data, which is used to validate the branch it belongs to. Assume there are only branches. If the validation passes, and the other three branches fail the validation, then the branches that fail the validation will be deleted directly.

[0158] III. By Branch Begin, If each element in the subfolder is treated as a leaf node, then the following four branches can be obtained:

[0159]

[0160]

[0161]

[0162]

[0163] Four, Each element within the set contains validation data, which is used to validate the branch it belongs to. Assume there are only branches. If the validation passes, and the other three branches fail the validation, then the branches that fail the validation will be deleted directly.

[0164] comprehensive The data within this branch, consisting of bits B = b0 + b1 + b2, represents the original data sent by a user equipment within packet g, where b0 is... Data other than verification data (valid data sent by the user equipment), b1 is Data other than checksum data (valid data sent by the user equipment), b2 is Data other than verification data (valid data sent by the user equipment).

[0165] Then, in sequence Decoding the tree code for the root node, the specific processing is the same as... The decoding of the tree code for the root node is the same, so it will not be elaborated here.

[0166] For group g, the k groups of B bits of data are obtained by decoding through the tree code decoder, denoted as:

[0167]

[0168] That is, it means that the received uplink data includes uplink data sent by k user equipment in packet g.

[0169] The combined outputs of the treecode decoders for the G groups represent the original data sent by all user equipment in the G groups, denoted as:

[0170]

[0171] in, Each element in the array represents the original B-bit data sent by a user equipment.

[0172] The data transmission method provided in this application can be applied in a static access scenario, eliminating the need for a random access process for each user equipment requiring uplink transmission. Therefore, communication with the base station is relatively minimal, effectively reducing power consumption of user equipment due to random access.

[0173] In addition, for the encoding end (user equipment), the encoding process mainly involves the mapping of the encoding position of the tree code, matrix compression, and OFDM modulation, which minimizes the complexity of the encoding.

[0174] Table 3 below shows the complexity of maximum likelihood decoding and tree code decoding.

[0175] Table 3

[0176]

[0177] For the decoding end (base station), the decoding complexity mainly comes from the quadratic complexity of the maximum likelihood decoder and the tree code decoder: the maximum likelihood decoder is sensitive to the number of OFDM symbols n for each packet, while the tree code decoder is sensitive to the number of user equipment K for each packet. g Relatively sensitive. Without grouping user equipment and uplink resources, n is the total number of OFDM symbols on the subcarrier, and K... g To determine the number of user equipments within the base station coverage area (cell), the method provided in this application groupes the user equipments and correspondingly groups the uplink resources, thus reducing n and K.g This reduces the complexity of decoding.

[0178] Based on the same technical concept, embodiments of this application provide a data transmission apparatus that can be deployed on any user equipment within the coverage area of ​​a base station. The base station coverage area contains multiple groups of user equipment. See [link to relevant documentation]. Figure 9 The device includes an acquisition module 910, a tree-structured code encoding module 920, a compression module 930, an OFDM modulation module 940, and a transmission module 950, wherein:

[0179] The acquisition module 910 is used to acquire the uplink resource information corresponding to the group, wherein the uplink resource information includes the frequencies of L subcarriers used for uplink communication and the position information of n OFDM symbols corresponding to the group on a single subcarrier, wherein L and n are positive integers;

[0180] The tree code encoding module 920 is used to encode the data to be sent and the verification data through the tree code encoder to obtain L sets of encoded data;

[0181] The compression module is used in 930 to compress each group of encoded data in the L groups of encoded data into codewords of length n using a compression matrix;

[0182] OFDM modulation module 940 is used to perform orthogonal frequency division multiplexing OFDM modulation on L groups of codewords of length n, wherein each group of codewords of length n occupies one subcarrier among the L subcarriers after modulation, and each codeword corresponds to one OFDM symbol among the n OFDM symbols on the occupied subcarrier.

[0183] The transmitting module 950 is used to transmit modulated data to the base station.

[0184] In one possible implementation, the device further includes a downlink synchronization module for:

[0185] Establish downlink synchronization with the base station.

[0186] In one possible implementation, the sending module 950 is further configured to send a random access request to the base station;

[0187] The device further includes a receiving module for:

[0188] Receive the random access response returned by the base station.

[0189] In one possible implementation, the acquisition module 910 is used for:

[0190] Obtain the uplink resource information corresponding to the group in the Broadcast Control Channel (BCCH).

[0191] In one possible implementation, the acquisition module 910 is used for:

[0192] Based on the group identifier corresponding to the group, multiple uplink resource information in the BCCH are descrambled sequentially until the uplink resource information corresponding to the group is obtained. Each uplink resource information corresponds to a user equipment of a group.

[0193] In one possible implementation, the sending module 950 is further configured to send a scheduling transmission message to the base station;

[0194] The receiving module is also used to receive conflict resolution messages sent by the base station.

[0195] In one possible implementation, the acquisition module 910 is used for:

[0196] Receive uplink resource information corresponding to the group to which the base station belongs.

[0197] It should be noted that the data transmission apparatus provided in the above embodiments is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the user equipment can be divided into different functional modules to complete all or part of the functions described above. In addition, the data transmission apparatus and the data transmission method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0198] Based on the same technical concept, embodiments of this application also provide a data transmission apparatus, which is deployed at a base station. The coverage area of ​​the base station includes multiple user equipment packets. See [link to relevant documentation]. Figure 10 The device includes a receiving module 1010, an OFDM demodulation module 1020, a sparse regression code decoding module 1030, and a tree code decoding module 1040, wherein:

[0199] The receiving module 1010 is used to receive data sent by the user equipment;

[0200] OFDM demodulation module 1020 is used to perform OFDM demodulation on the data and output L first data sets corresponding to each of the multiple packets. Each first data set includes n*S elements, where L is the number of subcarriers used by the user equipment for uplink communication in the multiple packets, n is the number of OFDM symbols corresponding to each packet on a single subcarrier, and S is the number of receiving antennas of the base station.

[0201] The sparse regression code decoding module 1030 is used to perform sparse regression code decoding on each first data set corresponding to each group to obtain L second data sets corresponding to each group, wherein the number of elements in each second set is greater than or equal to the number of user devices in each group.

[0202] The tree code decoding module 1040 is used to perform tree code decoding on the L second data sets corresponding to each group to obtain the original data corresponding to the group.

[0203] In one possible implementation, the sparse regression code decoding module 1030 is used for:

[0204] Perform maximum likelihood decoding on each first data set corresponding to each group.

[0205] In one possible implementation, the sparse regression code decoding module 1030 is used for:

[0206] Approximate information is iteratively decoded for each first data set corresponding to each group.

[0207] In one possible implementation, the device further includes a transmitting module for:

[0208] Multiple uplink resource messages are sent via BCCH, with each uplink resource message corresponding to a user equipment in a packet.

[0209] It should be noted that the data transmission apparatus provided in the above embodiments is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the base station can be divided into different functional modules to complete all or part of the functions described above. In addition, the data transmission apparatus and the data transmission method embodiments provided in the above embodiments belong to the same concept, and their specific implementation process can be found in the method embodiments, which will not be repeated here.

[0210] See Figure 11 This application provides a user equipment, which can be a smart grid monitoring device, a wildlife tracking device, an agricultural environmental monitoring device, etc. The user equipment includes a processor 110, a memory 120, and a communication component 130, etc.

[0211] The processor 110 may be a central processing unit (CPU), which may be used to perform encoding and decoding processes.

[0212] The memory 120 can be various volatile or non-volatile memory, such as solid-state disk (SSD), dynamic random access memory (DRAM), etc. The memory 120 can be used to store data, compress matrices, etc.

[0213] The communication component 130 can be a wired network connector, a wireless fidelity (WiFi) module, a Bluetooth module, a cellular network communication module, etc. The communication component 130 can be used to transmit data with other devices, which can be base stations or other user equipment.

[0214] See Figure 12 This application provides a base station, which may include a processor 210, a memory 220, and a communication component 230, etc.

[0215] The processor 210 may be a central processing unit (CPU), which can be used to perform encoding and decoding processing.

[0216] The memory 220 can be various volatile or non-volatile memory, such as SSD, DRAM, etc. The memory 220 can be used to store data.

[0217] The communication component 230 can be a wired network connector, a WiFi module, a Bluetooth module, a cellular network communication module, etc. The communication component 230 can be used to transmit data with other devices, such as user equipment, other base stations, etc.

[0218] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When these computer program instructions are loaded and executed on a device, they generate, in whole or in part, the processes or functions described in the embodiments of this application. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic cable, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to the device or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, and magnetic tape), an optical medium (e.g., digital video disk (DVD), etc.), or a semiconductor medium (e.g., solid-state drive).

[0219] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0220] The above description is only one embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A method for data transmission, characterized in that, The method is applied to any user equipment within the coverage area of ​​a base station, where there are multiple groups of user equipment within the coverage area of ​​the base station, and the method includes: Obtain the uplink resource information corresponding to the group, wherein the uplink resource information includes the frequencies of L subcarriers used for uplink communication, the location information of n orthogonal frequency division multiplexing (OFDM) symbols corresponding to the group on a single subcarrier, and the structure information of the OFDM symbols, wherein the structure information of the OFDM symbols includes the cyclic prefix length, the cyclic prefix length being greater than or equal to the sum of the delay caused by the user equipment's uplink synchronization failure and the delay caused by the user equipment's own multipath effect, and L and n are positive integers; The data to be sent and the verification data are encoded using a tree code encoder to obtain L sets of encoded data; Each group of coded data in the L groups is compressed into a codeword of length n using a compression matrix; OFDM modulation is performed on L groups of codewords of length n and the cyclic prefix is ​​added. After modulation, each group of codewords of length n occupies one subcarrier among the L subcarriers, and each codeword corresponds to one OFDM symbol among the n OFDM symbols on the occupied subcarrier. The modulated data is sent to the base station.

2. The method according to claim 1, characterized in that, Before obtaining the uplink resource information corresponding to the group, the method further includes: Establish downlink synchronization with the base station.

3. The method according to claim 2, characterized in that, After establishing downlink synchronization with the base station, the method further includes: Send a random access request to the base station; Receive the random access response returned by the base station.

4. The method according to claim 2 or 3, characterized in that, The step of obtaining the uplink resource information corresponding to the group includes: Obtain the uplink resource information corresponding to the group in the Broadcast Control Channel (BCCH).

5. The method according to claim 4, characterized in that, The step of obtaining the uplink resource information corresponding to the group in the BCCH includes: Based on the group identifier corresponding to the group, multiple uplink resource information in the BCCH are descrambled sequentially until the uplink resource information corresponding to the group is obtained. Each uplink resource information corresponds to a user equipment of a group.

6. The method according to claim 3, characterized in that, After receiving the random access response returned by the base station, the method further includes: Send a scheduling transmission message to the base station; Receive the conflict resolution message sent by the base station.

7. The method according to claim 6, characterized in that, The step of obtaining the uplink resource information corresponding to the group includes: Receive uplink resource information corresponding to the group to which the base station belongs.

8. A method for data transmission, characterized in that, The method is applied to a base station, the base station's coverage area including multiple user equipment groups, the method comprising: The system receives data sent by a user equipment, wherein the data sent by each user equipment is obtained by OFDM modulation of L groups of codewords of length n. After modulation, each group of codewords of length n occupies one of the L subcarriers used for uplink communication in the group to which the user equipment belongs, and each codeword corresponds to one of the n OFDM symbols on the occupied subcarrier. The data is demodulated using OFDM to remove the cyclic prefix, and L first data sets corresponding to each of the multiple packets are output. The length of the cyclic prefix is ​​greater than or equal to the sum of the delay caused by the uplink synchronization failure of the user equipment and the delay caused by the multipath effect of the user equipment itself. Each first data set includes n*S elements, where L is the number of subcarriers used by the user equipment for uplink communication in the multiple packets, n is the number of OFDM symbols corresponding to each packet on a single subcarrier, and S is the number of receiving antennas of the base station. Sparse regression code decoding is performed on each first data set corresponding to each group to obtain L second data sets corresponding to each group, wherein the number of elements in each second set is greater than or equal to the number of user devices in each group; For each group, there are L second data sets. The L second data sets corresponding to the group are decoded using a tree code to obtain the original data corresponding to the group.

9. The method according to claim 8, characterized in that, The step of decoding the sparse regression code for each first data set corresponding to each group includes: Perform maximum likelihood decoding on each first data set corresponding to each group.

10. The method according to claim 8, characterized in that, The step of decoding the sparse regression code for each first data set corresponding to each group includes: Approximate information is iteratively decoded for each first data set corresponding to each group.

11. The method according to any one of claims 8-10, characterized in that, The method further includes: Multiple uplink resource messages are sent via BCCH, with each uplink resource message corresponding to a user equipment in a packet.

12. A data transmission apparatus, characterized in that, The device is applied to any user equipment within the coverage area of ​​a base station, where there are multiple groups of user equipment within the coverage area of ​​the base station, and the device includes: The acquisition module is used to acquire uplink resource information corresponding to the group. The uplink resource information includes the frequencies of L subcarriers used for uplink communication, the position information of n OFDM symbols corresponding to the group on a single subcarrier, and the structure information of the OFDM symbols. The structure information of the OFDM symbols includes the cyclic prefix length, which is greater than or equal to the sum of the delay caused by the user equipment's uplink synchronization failure and the delay caused by the user equipment's multipath effect. L and n are positive integers. The tree code encoding module is used to encode the data to be sent and the verification data through the tree code encoder to obtain L sets of encoded data; A compression module is used to compress each group of encoded data in the L groups of encoded data into codewords of length n using a compression matrix; The OFDM modulation module is used to perform orthogonal frequency division multiplexing OFDM modulation on L groups of codewords of length n and add a cyclic prefix. After modulation, each group of codewords of length n occupies one subcarrier among the L subcarriers, and each codeword corresponds to one OFDM symbol among the n OFDM symbols on the occupied subcarrier. The transmitting module is used to transmit modulated data to the base station.

13. The apparatus according to claim 12, characterized in that, The device further includes a downlink synchronization module for: Establish downlink synchronization with the base station.

14. The apparatus according to claim 13, characterized in that, The sending module is also used to send a random access request to the base station; The device further includes a receiving module for: Receive the random access response returned by the base station.

15. The apparatus according to claim 13 or 14, characterized in that, The acquisition module is used for: Obtain the uplink resource information corresponding to the group in the Broadcast Control Channel (BCCH).

16. The apparatus according to claim 15, characterized in that, The acquisition module is used for: Based on the group identifier corresponding to the group, multiple uplink resource information in the BCCH are descrambled sequentially until the uplink resource information corresponding to the group is obtained. Each uplink resource information corresponds to a user equipment of a group.

17. The apparatus according to claim 14, characterized in that, The sending module is also used to send a scheduling transmission message to the base station; The receiving module is also used to receive conflict resolution messages sent by the base station.

18. The apparatus according to claim 17, characterized in that, The acquisition module is used for: Receive uplink resource information corresponding to the group to which the base station belongs.

19. A data transmission apparatus, characterized in that, The device is used in a base station, the base station coverage area including multiple user equipment packets, the device comprising: The receiving module is used to receive data sent by the user equipment. The data sent by each user equipment is obtained by OFDM modulation of L groups of codewords of length n. After modulation, each group of codewords of length n occupies one of the L subcarriers used for uplink communication of the group to which the user equipment belongs, and each codeword corresponds to one of the n OFDM symbols on the occupied subcarrier. The OFDM demodulation module is used to perform OFDM demodulation on the data to remove the cyclic prefix and output L first data sets corresponding to each of the multiple packets. The length of the cyclic prefix is ​​greater than or equal to the sum of the delay caused by the uplink synchronization failure of the user equipment and the delay caused by the multipath effect of the user equipment itself. Each first data set includes n*S elements, where L is the number of subcarriers used by the user equipment for uplink communication in the multiple packets, n is the number of OFDM symbols corresponding to each packet on a single subcarrier, and S is the number of receiving antennas of the base station. The sparse regression code decoding module is used to perform sparse regression code decoding on each first data set corresponding to each group to obtain L second data sets corresponding to each group, wherein the number of elements in each second set is greater than or equal to the number of user devices in each group. The tree code decoding module is used to perform tree code decoding on the L second data sets corresponding to each group to obtain the original data corresponding to the group.

20. The apparatus according to claim 19, characterized in that, The sparse regression code decoding module is used for: Perform maximum likelihood decoding on each first data set corresponding to each group.

21. The apparatus according to claim 19, characterized in that, The sparse regression code decoding module is used for: Approximate information is iteratively decoded for each first data set corresponding to each group.

22. The apparatus according to any one of claims 19-21, characterized in that, The device further includes a transmitting module for: Multiple uplink resource messages are sent via BCCH, with each uplink resource message corresponding to a user equipment in a packet.

23. A user equipment, characterized in that, The user equipment includes a processor and a memory, the memory storing at least one instruction, which is loaded and executed by the processor to implement the data transmission method as described in any one of claims 1 to 7.

24. A base station, characterized in that, The base station includes a processor and a memory, the memory storing at least one instruction, which is loaded and executed by the processor to implement the data transmission method as described in any one of claims 8 to 11.

25. A communication system, characterized in that, The communication system includes the user equipment as described in claim 23 and the base station as described in claim 24.

26. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which is loaded and executed by a processor to implement the data transmission method as described in any one of claims 1 to 7 or 8 to 11.

27. A computer program product, characterized in that, The computer program product includes a computer program stored in a computer-readable storage medium, the computer program being loaded and executed by a processor to implement the method of data transmission as described in any one of claims 1 to 7 or 8-11.

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