Method and device for transmitting signal

Abstract

The present application provides a method and apparatus for transmitting a signal, which is used to propose a diversity transmission scheme. The transmitting end divides a plurality of modulation symbols into a plurality of groups of modulation symbols; adds one or more preset symbols to the modulation symbols of each group to obtain extended symbols; then, performs a second-level precoding on at least one group of extended symbols corresponding to each antenna port group to obtain symbols corresponding to each antenna port in each antenna port group; in the second-level precoding, the dimension of the precoding matrix used by each precoding antenna port group is related to the number of the groups and the number of antenna ports included in the antenna port group. Finally, the transmitting end sends the symbols corresponding to each antenna port. The positions of the multiple groups of modulation symbols corresponding to each antenna port group in the extended symbols do not overlap with the positions of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols. Diversity transmission is achieved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a method and device for transmitting signals. Background Art

[0002] In mobile communication systems, signals transmitted between terminals and base stations are subject to multipath fading, resulting in poor signal quality or even complete signal reception at the receiving end. For example, terminals often operate in urban areas or other complex geographical environments, and their speed and direction of movement are random. After the signal from the transmitter (which can be either the terminal or the base station) undergoes reflections and scattering, the signal reaching the receiving end is often a superposition of multiple signals with varying amplitudes and phases. This causes random fluctuations in the received signal amplitude, resulting in multipath fading. Furthermore, signal obstruction by tall buildings (for example, when a terminal moves in front of a building facing away from the base station) or by undulating terrain can reduce the received signal amplitude. Furthermore, changing weather conditions can affect signal propagation, causing variations in the received signal amplitude and phase. All of these factors negatively impact mobile communications.

[0003] To improve the performance of mobile communication systems, diversity techniques can be used to enhance received signal quality. Diversity techniques utilize multiple transmission paths that carry the same information, have approximately equal average signal strength, and exhibit independent fading characteristics. Upon receiving these signals, the receiver can appropriately combine them to significantly reduce the impact of multipath fading, thereby improving transmission reliability.

[0004] Based on this, how to perform diversity transmission is a technical problem that needs to be solved. Summary of the Invention

[0005] The present application provides a method and apparatus for transmitting a signal, so as to propose a diversity transmission solution.

[0006] In a first aspect, a method for transmitting a signal (also referred to as a diversity communication method) is provided. First, a transmitter divides n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2. Then, the transmitter adds one or more preset symbols to the modulation symbols of the mth group to obtain the mth group of extended symbols; m is an integer ranging from 1 to M. It should be noted that the positions of the s groups of modulation symbols corresponding to the gth antenna port group in the s groups of extended symbols do not overlap with the positions of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols. Then, the transmitter performs second-level precoding on the s groups of extended symbols corresponding to the gth antenna port group to obtain symbols corresponding to each antenna port in the gth antenna port group. In the second-level precoding, the dimension of the precoding matrix used by the gth precoding antenna port group is related to s and the number of antenna ports included in the gth antenna port group; s is an integer greater than or equal to 1 and less than or equal to M, and g is an integer greater than or equal to 1. If g represents a group index, g may also start at 0. Finally, the transmitting end sends the symbol corresponding to each antenna port.

[0007] During the extension, the position of the s groups of modulation symbols corresponding to the g-th antenna port group in the symbols after the extension of the s groups does not overlap with the position of at least one group of modulation symbols corresponding to any other antenna port group in the symbols after the extension of the at least one group. Therefore, it can be guaranteed that the intersection of the subcarrier sets that transmit valid signals on any two antenna port groups is an empty set, thereby achieving diversity transmission. In addition, by mapping multiple modulation symbols to multiple groups and interleaving between groups, the same code block can be mapped to different groups, and then mapped to different frequency domain resources or different antennas, thereby achieving more robust and stable decoding performance. Furthermore, through precoding, the diversity in the frequency domain can be converted into diversity in the antenna, and simultaneous diversity in the spatial and frequency domains can be achieved, thereby improving the diversity gain. In addition, the precoding between different antenna port groups is independent of each other and does not affect each other. While utilizing the incoherent characteristics between antenna ports to ensure performance, it reduces the precoding dimension and reduces the processing complexity of the transmitting end.

[0008] In one possible implementation, when the transmitting end transmits the symbols corresponding to each antenna port, it may specifically perform first processing on the symbols corresponding to each antenna port and transmit the symbols. The first processing may include at least: subcarrier mapping (mapping the symbols corresponding to each antenna port to the subcarriers corresponding to the antenna port); inverse discrete Fourier transform (IFFT), inverse fast Fourier transform (CP), cyclic prefix (CP) addition, power adjustment, etc.

[0009] In a possible implementation, in an antenna port group, positions of any group of modulation symbols in any group of extended symbols do not overlap with positions of another group of modulation symbols in another group of extended symbols.

[0010] In a possible implementation, in an antenna port group, the position of any group of modulation symbols in any group of extended symbols is the same as the position of another group of modulation symbols in another group of extended symbols.

[0011] In one possible implementation, before adding one or more preset symbols to the mth group of modulation symbols to obtain the mth group of extended symbols, the transmitter may further perform a discrete Fourier transformation (DFT) on the mth group of modulation symbols. Furthermore, the transmitter may add one or more preset symbols to the symbols after performing the DFT on the mth group of modulation symbols to obtain the mth group of extended symbols.

[0012] In one possible implementation, the DFT size is the number of modulation symbols in the mth group, rather than the number n of modulation symbols before grouping. This size matches the number of modulation symbols in each group, reserving diversity space for subsequent frequency / spatial diversity. It also reduces the DFT dimension, thereby reducing the difficulty and complexity of the DFT.

[0013] In one possible implementation, M is greater than or equal to the number of antenna port groups, and M is less than or equal to the sum of the number of antenna ports in the antenna port groups. There are multiple options for the number of M, which can make grouping more flexible.

[0014] In one possible implementation, the positions of the modulation symbols of the mth group (if DFT is performed, the modulation symbols need to be replaced with the DFT symbols) in the mth group of expanded symbols are discontinuous; or continuous; or partially continuous and partially discontinuous. Multiple grouping methods can be used for grouping to provide greater flexibility.

[0015] In one possible implementation, when one or more preset symbols are added to the modulation symbols of the mth group to obtain the mth group of extended symbols, specifically, x preset symbols are added to every y modulation symbols in the mth group to obtain the mth group of extended symbols, where y is an integer greater than or equal to 1, and x is an integer greater than or equal to 1. It should be noted that if DFT is performed, the modulation symbols need to be replaced with the symbols after the DFT.

[0016] In one possible implementation, x is an integer multiple of y.

[0017] In a possible implementation, y is an integer multiple of the number of resource units RE included in the resource block group RBG.

[0018] In a possible implementation, the transmitting end receives indication information, where the indication information is used to determine the precoding matrix.

[0019] In one possible implementation, the indication information includes a precoding matrix index, which indicates a precoding matrix in a precoding matrix set. The precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission. The term "set" can also be replaced by a group or table. In this example, the precoding matrix for diversity transmission and the precoding matrix for non-diversity transmission are jointly indexed. This method only requires indicating the precoding matrix index for the transmitter to find the corresponding precoding matrix. This simple and accurate indication method.

[0020] In one possible implementation, the indication information includes: a precoding matrix index and an indication of diversity transmission. The indication of diversity transmission may be an explicit indication, for example, through a 1-bit indication. The indication of diversity transmission may also be implicitly indicated through a waveform, for example, an orthogonal frequency division multiplexing (OFDM) waveform corresponds to no diversity transmission, and a discrete Fourier transform-spreading OFDM (DFT-s-OFDM) waveform corresponds to diversity transmission. In this way, when the transmitting end determines to perform diversity transmission, it can search for the precoding matrix corresponding to the precoding matrix index in the precoding matrix used for diversity transmission, without mistakenly searching for the precoding matrix in the precoding matrix used for non-diversity transmission.

[0021] In one possible implementation, the indication information includes a precoding matrix index and a precoding matrix set identifier, where the precoding matrices in the identified precoding matrix set are used for diversity transmission. Thus, the transmitting end can search the identified precoding matrix set for the precoding matrix corresponding to the precoding matrix index.

[0022] In one possible implementation, the transmitter performs second-level precoding on the s groups of expanded symbols corresponding to the g-th antenna port group to obtain symbols corresponding to each antenna port in the g-th antenna port group. Furthermore, the transmitter performs first-level precoding on the v groups of expanded symbols. The size of the precoding matrix used in the first-level precoding is v*v, and elements in the precoding matrix of the first-level precoding are 0 and / or 1. The first-level precoding can implement selection of antenna ports or antenna port groups.

[0023] In one possible implementation, the precoding matrix for the first level precoding is a diagonal matrix or an anti-diagonal matrix. In one possible implementation, the precoding matrix for the first level precoding is a block diagonal matrix or a block anti-diagonal matrix.

[0024] In one possible implementation, the diagonal blocks or anti-diagonal blocks in the block diagonal matrix are unit matrices whose size is equal to the number of antenna ports in the antenna port group. In other words, a "block" is a unit matrix whose number of rows and columns is equal to the number of antenna ports in the antenna port group.

[0025] In a possible implementation, the transmitter generates modulation symbols using the following formula:

[0026] Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), It means i / M is rounded down, and j is the imaginary part.

[0027] In one possible implementation, the transmitting end adds one or more preset symbols to the modulation symbols of the mth group, and before obtaining the mth group of extended symbols, it can also filter out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

[0028] In a possible implementation, the transmitting end receives indication information, where the indication information is used to indicate a truncation factor, the value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor.

[0029] In a second aspect, a method for transmitting a signal (diversity communication) is provided. First, the transmitting end divides n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2. Then, the transmitting end performs second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group to obtain symbols corresponding to each antenna port in the g-th antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the g-th precoding antenna port group is related to the s and the number of antenna ports included in the g-th antenna port group, s is an integer greater than or equal to 1 and less than or equal to M, and g is an integer greater than or equal to 1. If g represents the index of the group, g can also start from 0. Next, the transmitting end maps the corresponding symbol of each antenna port to the subcarrier corresponding to the antenna port and sends it; wherein the subcarriers corresponding to any two antenna port groups do not overlap.

[0030] The subcarriers of the signals transmitted on any two antenna port groups do not overlap, achieving diversity transmission. In addition, by mapping multiple modulation symbols to multiple groups and interleaving between groups, the same code block can be mapped to different groups, and then mapped to different frequency domain resources or different antennas, achieving more robust and stable decoding performance. Furthermore, through precoding, the diversity in the frequency domain can be converted into diversity on the antenna, which can achieve simultaneous diversity in the spatial and frequency domains and improve diversity gain. In addition, the precoding between different antenna port groups is independent of each other and does not affect each other. While utilizing the incoherent characteristics between antenna ports to ensure performance, it reduces the precoding dimension and reduces the processing complexity of the transmitter.

[0031] In one possible implementation, the positions of the subcarriers corresponding to any antenna port group in the scheduling bandwidth are discontinuous; or, the positions of the subcarriers corresponding to any antenna port group in the scheduling bandwidth are continuous; or, the subcarriers corresponding to any antenna port group in the scheduling bandwidth are partially continuous and partially discontinuous.

[0032] In a possible implementation, in an antenna port group, subcarriers corresponding to any two antenna ports do not overlap; or, in an antenna port group, subcarriers corresponding to any two antenna ports are the same.

[0033] In one possible implementation, the transmitting end performs a second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group, and before obtaining the symbols corresponding to each antenna port in the g-th antenna port group, it can also perform a discrete Fourier transform DFT on the m-th group of modulation symbols.

[0034] In one possible implementation, the DFT size is the number of symbols in the mth group of modulation symbols, rather than the number n of modulation symbols before grouping. This size matches the number of modulation symbols in each group, reserving diversity space for subsequent frequency / spatial diversity. It also reduces the DFT dimension, thereby reducing the difficulty and complexity of the DFT.

[0035] In one possible implementation, M is greater than or equal to the number of antenna port groups, and M is less than or equal to the sum of the number of antenna ports in the antenna port groups. There are multiple options for the number of M, which can make grouping more flexible.

[0036] In a possible implementation, the transmitting end receives indication information, where the indication information is used to determine the precoding matrix.

[0037] In one possible implementation, the indication information includes a precoding matrix index, which indicates a precoding matrix in a precoding matrix set. The precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission. The term "set" can also be replaced by a group or table. In this example, the precoding matrix for diversity transmission and the precoding matrix for non-diversity transmission are jointly indexed. This method only requires indicating the precoding matrix index for the transmitter to find the corresponding precoding matrix. This simple and accurate indication method.

[0038] In one possible implementation, the indication information includes: a precoding matrix index and an indication of diversity transmission. The indication of diversity transmission may be an explicit indication, for example, through a 1-bit indication. The indication of diversity transmission may also be implicitly indicated through a waveform, for example, an orthogonal frequency division multiplexing (OFDM) waveform corresponds to no diversity transmission, and a discrete Fourier transform-spreading OFDM (DFT-s-OFDM) waveform corresponds to diversity transmission. In this way, when the transmitting end determines to perform diversity transmission, it can search for the precoding matrix corresponding to the precoding matrix index in the precoding matrix used for diversity transmission, without mistakenly searching for the precoding matrix in the precoding matrix used for non-diversity transmission.

[0039] In one possible implementation, the indication information includes a precoding matrix index and a precoding matrix set identifier, where the precoding matrices in the identified precoding matrix set are used for diversity transmission. Thus, the transmitting end can search the identified precoding matrix set for the precoding matrix corresponding to the precoding matrix index.

[0040] In one possible implementation, the transmitter performs second-level precoding on s groups of modulated symbols (or symbols after DFT) corresponding to the g-th antenna port group to obtain symbols corresponding to each antenna port in the g-th antenna port group. Furthermore, the transmitter performs first-level precoding on v groups of modulated symbols (or symbols after DFT), wherein the size of the precoding matrix used in the first-level precoding is v*v, and the elements in the precoding matrix of the first-level precoding are 0 and / or 1. The first-level precoding can implement the selection of antenna ports or antenna port groups.

[0041] In a possible implementation, the precoding matrix of the first-level precoding is a diagonal matrix or an anti-diagonal matrix.

[0042] In a possible implementation, the precoding matrix of the first-level precoding is a block diagonal matrix or a block anti-diagonal matrix.

[0043] In one possible implementation, the blocks in the block diagonal matrix are unit matrices whose size is equal to the number of antenna ports in the antenna port group. That is, the diagonal blocks or anti-diagonal blocks in the block diagonal matrix are unit matrices, and the number of rows and columns of the unit matrix is ​​equal to the number of antenna ports in the antenna port group.

[0044] In a possible implementation, the transmitter generates modulation symbols using the following formula:

[0045] Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), It means i / M is rounded down, and j is the imaginary part.

[0046] In one possible implementation, the transmitting end performs second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group. Before obtaining the symbols corresponding to each antenna port in the g-th antenna port group, the first L1 and / or last L2 symbols in the m-th group of modulation symbols can also be filtered out, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

[0047] In a possible implementation, the transmitting end receives indication information, where the indication information is used to indicate a truncation factor, the value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor.

[0048] In a third aspect, a communication device is provided, wherein the device implements the functions of the first aspect and any possible implementation of the first aspect, or implements the functions of the second aspect and any possible implementation of the second aspect. These functions may be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more functional modules corresponding to the above-mentioned functions.

[0049] In a fourth aspect, a communication device is provided, comprising a processor and a memory; the memory is used to store computer programs or instructions; the processor is used to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, it is used to implement the function of the sending end in the method of the first aspect and any possible implementation of the first aspect, or to implement the function of the sending end in the second aspect and any possible implementation of the second aspect.

[0050] In one possible implementation, the apparatus may further include a transceiver configured to transmit a signal processed by the processor or receive a signal input to the processor. The transceiver may perform the transmitting action or receiving action performed by the transmitting end in the first aspect and any possible implementation of the first aspect; or perform the transmitting action or receiving action performed by the transmitting end in the second aspect and any possible implementation of the second aspect.

[0051] In a fifth aspect, the present application provides a chip system, which includes one or more processors (also referred to as processing circuits), and the processors are electrically coupled to a memory (also referred to as a storage medium); the memory may be located in the chip system or not in the chip system; the memory is used to store computer programs or instructions; the processor is used to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, they are used to implement the function of the sending end in the method of the above-mentioned first aspect and any possible implementation of the first aspect, or to implement the function of the sending end in the above-mentioned second aspect and any possible implementation of the second aspect.

[0052] In one possible implementation, the chip system may further include an input / output interface, configured to output signals processed by the processor or receive signals input to the processor. The input / output interface may perform the sending action or receiving action performed by the sending end in the first aspect and any possible implementation of the first aspect; or perform the sending action or receiving action performed by the sending end in the second aspect and any possible implementation of the second aspect. Specifically, the output interface performs the sending action, and the input interface performs the receiving action.

[0053] In a possible implementation, the chip system may be composed of a chip, or may include a chip and other discrete devices.

[0054] In a sixth aspect, a computer-readable storage medium is provided for storing a computer program, wherein the computer program includes instructions for implementing the functions of the first aspect and any possible implementation of the first aspect, or instructions for implementing the functions of the second aspect and any possible implementation of the second aspect.

[0055] Alternatively, a computer-readable storage medium is used to store a computer program, which, when executed by a computer, can enable the computer to execute the method executed by the sending end in the above-mentioned first aspect and any possible implementation of the first aspect, or execute the method executed by the sending end in the above-mentioned second aspect and any possible implementation of the second aspect.

[0056] In the seventh aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method executed by the sending end in the above-mentioned first aspect and any possible implementation of the first aspect, or to execute the method executed by the sending end in the above-mentioned second aspect and any possible implementation of the second aspect.

[0057] In an eighth aspect, a communication device is provided, comprising a processor; the processor is configured to execute a computer program or instructions, and when the computer program or instructions are executed, the computer program or instructions are configured to implement the functions of the transmitting end in the method of the first aspect and any possible implementation of the first aspect, or implement the functions of the transmitting end in the method of the second aspect and any possible implementation of the second aspect. The computer program or instructions may be stored in the processor or in a memory coupled to the processor. The memory may be located in the communication device or not.

[0058] In one possible implementation, the apparatus further includes a communication interface configured to transmit a signal processed by the processor or receive a signal input to the processor. The communication interface may perform the transmitting or receiving action performed by the transmitting end in the first aspect and any possible implementation of the first aspect, or perform the transmitting or receiving action performed by the transmitting end in the second aspect and any possible implementation of the second aspect.

[0059] The technical effects of the above-mentioned third to eighth aspects can refer to the descriptions in the first to second aspects, and the repeated parts will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic diagram of a communication system in an embodiment of the present application;

[0061] Figure 2 This is a schematic diagram of a short-delay cyclic delay diversity (SD-CDD) diversity communication process in an embodiment of the present application;

[0062] Figure 3 This is a schematic diagram of a diversity communication process in an embodiment of the present application;

[0063] Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e They are respectively schematic diagrams of a diversity communication process in an embodiment of the present application;

[0064] Figure 5a 、 Figure 5b and Figure 5cThey are respectively a grouping method in the embodiment of the present application;

[0065] Figure 6a 、 Figure 6b and Figure 6c They are respectively an expansion method in the embodiment of the present application;

[0066] Figure 7 This is a schematic diagram of truncation filtering in an embodiment of the present application;

[0067] Figure 8 This is a schematic diagram of a diversity communication process in an embodiment of the present application;

[0068] Figure 9 This is a structural diagram of a diversity communication device in an embodiment of the present application;

[0069] Figure 10 This is a structural diagram of a diversity communication device in an embodiment of the present application;

[0070] Figure 11 This is a terminal structure diagram in an embodiment of the present application. DETAILED DESCRIPTION

[0071] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0072] To facilitate understanding of the technical solutions of the embodiments of the present application, the system architecture of the diversity communication method provided in the embodiments of the present application is briefly described below. It is understood that the system architecture described in the embodiments of the present application is intended to more clearly illustrate the technical solutions of the embodiments of the present application and does not constitute a limitation on the technical solutions provided in the embodiments of the present application.

[0073] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: wireless local area network (WLAN) communication system, long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or new radio (NR), and future communication systems.

[0074] To facilitate understanding of the embodiments of the present application, the application scenarios of the present application are introduced below. The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Ordinary technicians in this field can know that with the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0075] like Figure 1 The communication system shown includes a network device and a terminal, and the network device and the terminal can use air interface resources for wireless communication. Air interface resources can include one or more of time domain resources, frequency domain resources, code domain resources, and space domain resources. In addition, the present application can also be applied to a communication system between terminals or a communication system between network devices.

[0076] In order to improve the performance of mobile communication systems, diversity techniques can be used to improve the quality of received signals. Figure 2 As shown, a schematic diagram of a process of short delay cyclic delay diversity (SD-CDD) diversity communication is provided, which specifically includes the following steps:

[0077] Step 201: The transmitter modulates the coded bits of the transport block (TB) after encoding to obtain a plurality of modulated symbols, which may be referred to as modulation symbols. The modulation symbols may also be referred to as complex symbols.

[0078] When the transmitting end has data to send to the receiving end, the transmitting end can perform cyclic redundancy check (CRC) addition, channel coding, code block segmentation, rate matching, data control multiplexing, scrambling and other operations on the transmission block to obtain multiple encoded bits. The encoded bits are then modulated, that is, constellation mapping, to obtain multiple modulation symbols. The modulation method can be, for example, quadrature amplitude modulation (QAM), or offset quadrature amplitude modulation (OQAM), or binary phase shift keying (BPSK), or pi / 2-BPSK, or QPSK, or pi / 4-QPSK, or 16QAM, or 64QAM, or 256QAM, or 1024QAM, or amplitude phase shift keying (APSK). The modulation order can be 1 or 2 or 4 or 6 or 8, etc., and the modulation order is related to the modulation method. This application does not limit the modulation method and modulation order.

[0079] Step 202: The transmitter performs a discrete Fourier transform (DFT) on the multiple modulated symbols. The DFT operation may also be referred to as "transform precoding." Step 202 is optional. If the DFT is not performed, the resulting signal is an OFDM signal. If the DFT is performed, the resulting signal is a DFT-s-OFDM signal. A symbol after the DFT operation may be referred to as a complex symbol.

[0080] In one example, the transmitter may group the modulation symbols and perform DFT on the group basis. For example, the grouping may be based on DFT-s-OFDM, where the modulation symbols of the same DFT-s-OFDM are grouped together. For example, in step 201, the number of modulated symbols is 1200, the scheduling bandwidth of a DFT-s-OFDM is 10 resource blocks (RBs), and a resource block RB includes 12 resource elements (REs). Therefore, each group of 120 modulation symbols is subjected to a 120-point DFT transform to the frequency domain.

[0081] Step 203: Precode the DFT symbols and map them to multiple antenna ports.

[0082] Figure 2While two antenna ports are used as an example for illustration, in actual applications, there may be more antenna ports, such as four or eight. Optionally, the symbols obtained in step 202 can be directly mapped to multiple antenna ports without undergoing precoding in step 203, so step 203 is optional. The precoding here can be precoding for non-codebook transmission or precoding for codebook transmission. Whether the symbols mapped to the two antenna ports are the same or different depends on the elements in the precoding matrix.

[0083] It should be noted that in Figure 2 In the example, the precoding matrix is ​​selected according to the number of antenna ports. Figure 3 In the example of , a precoding matrix is ​​selected according to the number of antenna ports included in the antenna port group.

[0084] Step 204: SD-CDD operates on one of the antennas (ie, one antenna port), generally causing a time domain shift (ie, a cyclic shift) by equivalently performing frequency domain weighting.

[0085] Step 205: Map the symbols on each antenna port to the frequency domain resources corresponding to the antenna port, that is, perform subcarrier mapping.

[0086] It should be noted that in Figure 2 In the example, the frequency domain resources corresponding to the two antenna ports are exactly the same, and in the following Figure 8 In the example, the frequency domain resources corresponding to different antenna ports do not overlap, that is, they are different.

[0087] Step 206: Perform an inverse fast Fourier transform (IFFT) and add a cyclic prefix (CP) to the frequency domain signal after frequency domain resource mapping to obtain a DFT-s-OFDM signal or an OFDM signal. The DFT-s-OFDM signal or OFDM signal can then be transmitted on the corresponding antenna port.

[0088] In this SD-CDD diversity communication solution, although the two signals are sent out one after the other through the SD-CDD operation in step 204, the time domain resources occupied by the two signals are still the same. The "one after the other" here does not refer to different time domain resources, but is caused by different sampling points.

[0089] SD-CDD achieves diversity by introducing short delays between multiple antenna ports, sending signals at different times. The receiver processes the signals from these multiple antenna ports as a whole. As a result, the received signal experiences significantly more multipath than a single antenna port, increasing the frequency selectivity of the channel and enabling the receiver to achieve greater frequency-domain diversity gain. In other words, SD-CDD converts antenna diversity into frequency-domain diversity.

[0090] However, SD-CDD technology also has some drawbacks. For example, performance gain depends on channel conditions. When the channel itself is highly frequency-selective, the gain achieved by SD-CDD is small. For another example, the demodulation and decoding of the DFT-s-OFDM waveform is performed in the time domain after the inverse discrete Fourier transform (IDFT). The coefficients used for decoding are obtained by averaging the frequency-domain equalization coefficients over the entire bandwidth. Therefore, the gain from increasing frequency selectivity is small. For another example, when the bandwidth is small, the space for cyclic shift is small, and the frequency selectivity caused by cyclic shift is limited, making it difficult to achieve gain. For another example, SD-CDD increases channel multipath while increasing the channel delay spread. When the delay spread exceeds the CP range, the channel estimation performance deteriorates.

[0091] Based on this, this application proposes a variety of diversity communication schemes. The diversity scheme proposed in this application can obtain the diversity gain of the transmitting antenna port under both OFDM and DFT-s-OFDM waveforms, and the proposed scheme is less affected by factors such as channel conditions and bandwidth size, and can provide stable diversity benefits in various application scenarios.

[0092] To facilitate understanding of the embodiments of the present application, some terms used in the embodiments of the present application are explained below to facilitate understanding by those skilled in the art.

[0093] 1) Network equipment, a device capable of providing a random access function for a terminal device or a chip that can be set in the device, the device including but not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home evolved NodeB, or home Node B, HNB), baseband unit (BBU), access point (AP) in a wireless fidelity (WIFI) system, wireless relay node, wireless backhaul node, transmission point (TRP or transmission point, TP), etc., and can also be a gNB in ​​a 5G, such as NR, system, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a baseband unit (BBU) or a distributed unit (DU). unit) etc.

[0094] 2) Terminal devices, also known as user equipment (UE), mobile station (MS), mobile terminal (MT), or terminal, are devices that provide voice and / or data connectivity to users. For example, terminal devices include handheld devices and vehicle-mounted devices with wireless connectivity. Currently, terminal devices can include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, or wireless terminals with vehicle-to-vehicle (V2V) connectivity.

[0095] 3) Diversity techniques utilize multiple signal paths to transmit information, combining these signals appropriately at the receiving end to significantly reduce the impact of multipath fading and improve transmission reliability. These multiple signal paths are characterized by transmitting the same information, having approximately equal average signal strength, and fading independently of each other. Simply put, if one path experiences a deep fade, another relatively independent path may still contain a strong signal. Therefore, two or more of these signals can be combined, improving both the instantaneous and average signal-to-noise ratios at the receiving end.

[0096] 4) Antenna Port: An antenna is a device that effectively radiates electromagnetic waves in a specific spatial direction or effectively receives electromagnetic waves from a specific spatial direction. The definition of an antenna port in 3GPP protocols 36.211 (LTE) and 38.211 (NR) states that the channel through which a symbol transmitted through an antenna port can be derived from the channel through which another symbol propagated through the same antenna.

[0097] Antenna ports in 3GPP are also called logical antenna ports. There are several possible implementations of the correspondence between antenna ports and physical antennas:

[0098] One possibility is that the number of antenna ports is equal to the number of physical antennas and corresponds one-to-one;

[0099] One possibility is that the number of antenna ports is equal to the number of physical antennas but not one-to-one corresponding. For example, the antenna port signal is mapped to the physical antenna after being precoded.

[0100] One possibility is that the number of antenna ports is smaller than the number of physical antennas. For example, one antenna port may correspond to an array composed of multiple physical antennas.

[0101] The antenna ports mentioned in this application are similar to the antenna ports defined in the 3GPP protocol and can be regarded as a method of identifying channels. The antenna ports in this application can be physical antenna ports or logical antenna ports. In this application, when the antenna port is a logical antenna port, one logical antenna port corresponds to one or more physical antenna ports, and different logical antenna ports correspond to different physical antenna ports, and the physical antenna ports corresponding to different logical antenna ports are allowed to overlap.

[0102] 6) Peak to average power ratio (PAPR):

[0103] The amplitude of wireless signals is constantly changing when observed in the time domain, so the instantaneous transmission power of wireless signals is not constant.

[0104] Peak-to-average power ratio (PAPR), also known as peak-to-average power ratio, can be expressed as follows:

[0105] Among them, x i Represents a set of discrete values ​​in the time domain of a sequence; max|x i | 2 ), which represents the maximum value of the square of the discrete value in the time domain; mean|x i | 2 , which represents the average value of the square of discrete values ​​in the time domain.

[0106] An OFDM symbol is composed of the superposition of multiple independently modulated subcarrier signals. When the subcarriers have the same or similar phases, the superimposed signal is modulated by the same initial phase signal, resulting in a large instantaneous power peak. This results in a high PAPR. High PAPR can lead to nonlinear signal distortion, causing significant spectrum spread interference and in-band signal distortion, degrading system performance.

[0107] 7) Introduce several precoding matrices:

[0108] Group A: Precoding matrix from single stream to dual antennas:

[0109]

[0110] Group B: Precoding matrix from two streams to two antennas:

[0111]

[0112] 8) The existing pi / 2-BPSK modulation formula is:

[0113] To maintain the low PAPR characteristics of pi / 2-BPSK, the present application provides an enhanced pi / 2-BPSK modulation. Specifically, when multiple modulation symbols (i.e., n-divided modulation symbols in the present application) are divided into M groups, the modulation symbols after enhanced pi / 2-BPSK modulation maintain the same initial phase within the M modulation symbols, while a pi / 2 phase shift is applied between the M modulation symbols. In this way, multiple (hereinafter referred to as n) modulation symbols are divided into M groups, and the phase shift characteristics of pi / 2-BPSK are preserved in each group of modulation symbols.

[0114] The enhanced pi / 2-BPSK modulation formula proposed in this application can be: (the "enhanced pi / 2-BPSK" here is only to distinguish it from the pi / 2-BPSK in the prior art. The enhanced pi / 2-BPSK can also be defined as other names without limitation).

[0115] or;

[0116]

[0117] Where M is the number of groups, M is an integer greater than or equal to 2, b represents a bit sequence, the elements in b are 0 or 1, b(i) is the i-th bit in the bit sequence (the bit sequence is usually a coded bit sequence), d(i) is the modulation symbol corresponding to b(i), i is an integer greater than or equal to 0, It means that i / M is rounded down, j is the imaginary part, and j*j=-1.

[0118] In a specific example, M is 2, that is, the above formula is applicable to dividing into 2 groups.

[0119] In another specific example, M is 4, that is, the above formula is applicable to dividing into 4 groups.

[0120] If ((1-2b(i))+j(1-2b(i))) / sqrt(2) is understood as the BPSK sequence, then it can be seen from the above formula that:

[0121] When i=0, 1, ..., M-1, the phase shift of the pi / 2BPSK sequence relative to the BPSK sequence is 0;

[0122] When i=M, M+1, ..., 2M-1, the phase shift of the pi / 2BPSK sequence relative to the BPSK sequence is pi / 2.

[0123] Next, we will introduce the phase shift of pi / 2 in units of M:

[0124] When M is 2, in formula 1, i=0 to i=15 correspond to mod 2 is: 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1; that is, the phase shifts relative to the BPSK sequence are 0, 0, pi / 2, pi / 2, 0, 0, pi / 2, pi / 2, 0, 0, pi / 2, pi / 2, 0, 0, pi / 2, pi / 2.

[0125] When M is 4, in formula 1, i=0 to i=15 correspond to mod 2 is: 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1; that is, the phase shifts relative to the BPSK sequence are 0, 0, 0, 0, pi / 2, pi / 2, pi / 2, pi / 2, 0, 0, 0, 0, pi / 2, pi / 2, pi / 2, pi / 2.

[0126] When M is 2, in formula 2, i=0 to i=15 correspond to mod 4 is: 0, 0, 1, 1, 2, 2, 3, 3, 0, 0, 1, 1, 2, 2, 3, 3; that is, the phase shifts relative to the BPSK sequence are 0, 0, pi / 2, pi / 2, pi, pi, 3pi / 2, 3pi / 2, 0, 0, pi / 2, pi / 2, pi, pi, 3pi / 2, 3pi / 2 respectively.

[0127] When M is 4, in formula 2, i=0 to i=15 correspond to mod 4 is: 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3; that is, the phase shifts relative to the BPSK sequence are 0, 0, 0, 0, pi / 2, pi / 2, pi / 2, pi, pi, pi, 3pi / 2, 3pi / 2, 3pi / 2, 3pi / 2 respectively.

[0128] 9) This application involves dividing multiple antenna ports into an antenna port group. Several division methods are introduced below.

[0129] For example, the division of antenna port groups can be performed based on the coherence between antenna ports in the UE:

[0130] For example, the UE may report the following coherence characteristics to the network device (using IE: pusch-TransCoherence):

[0131] "nonCoherent": There is no coherence between antenna ports, and inter-coherent encoding cannot be performed between antenna ports.

[0132] "partialCoherent": Some antenna ports are coherent, and coherent antenna ports can be inter-encoded.

[0133] "fullCoherent": All antenna ports are coherent and can be interleaved.

[0134] When the UE reports partial coherence capability, that is, reports partialCoherent, the antenna port groups can be divided according to the following methods:

[0135] All or some coherent antenna ports are grouped into the same antenna port group. For example, if a UE has four antenna ports (antenna port 0 to antenna port 3), antenna ports 0 and 2 can perform coherent transmission, and antenna ports 1 and 3 can perform coherent transmission, then antenna ports 0 and 2 can be grouped into antenna port group 1, and antenna ports 1 and 3 can be grouped into antenna port group 2.

[0136] When the UE reports no coherent capability, that is, reports "nonCoherent", the number of antenna port groups can be equal to the number of antenna ports.

[0137] Here, the definition of antenna port is as described above. Optionally, antenna port also refers to the antenna port through which the UE sends SRS.

[0138] It should be understood that the UE may report the port coherence during its uplink MIMO transmission in other ways.

[0139] The division of antenna port groups can also be directly configured by the network device. For example, if a UE has four antenna ports, the network device can configure antenna ports 0 and 1 to form antenna port group 1, and antenna ports 2 and 3 to form antenna port group 2. The network device can configure antenna port groups through signaling such as RRC or MAC CE. Optionally, the UE can report to the network device the UE's recommended antenna port grouping method or related information about the antenna port grouping.

[0140] 10) Extended symbol, also called extended signal.

[0141] The symbols corresponding to each antenna obtained after precoding the extended symbols (signals) may also be referred to as "signals".

[0142] 11) Block diagonal matrix:

[0143] Assume A is an n-order square matrix. If the sub-blocks of A on the non-main diagonal are all zero matrices, and the sub-blocks on the main diagonal are all square matrices, that is: Where O represents the zero matrix, A1, A2, A3, and A4 are all square matrices, so A is called a block diagonal matrix.

[0144] The block anti-diagonal matrix (or inverse block diagonal matrix) is: The diagonals of A1, A2, A3, and A4 in the block diagonal matrix are different from the diagonals of A1, A2, A3, and A4 in the block anti-diagonal matrix and can be understood as being opposite.

[0145] The following is a detailed description of the solution with reference to the accompanying drawings. The features or contents marked with dotted lines in the accompanying drawings can be understood as optional operations or optional structures of the embodiments of the present application.

[0146] like Figure 3 The figure shows a schematic diagram of a diversity communication process, using the example of a transmitter sending data to a receiver. In one example, the transmitter is a terminal and the receiver is a network device. In another example, the transmitter is a network device and the receiver is also a network device. In another example, the transmitter is a terminal and the receiver is also a terminal.

[0147] Figure 3 The following steps are involved:

[0148] Step 301: The transmitter modulates a plurality of coded bits after encoding a transport block (TB) to obtain a plurality of modulated symbols, which may be referred to as modulation symbols or complex symbols.

[0149] In one possible implementation, after encoding a transport block, a rate matching module generates multiple coding blocks. Multiple bits within different coding blocks are modulated to obtain modulated symbols. The number of coding blocks can be equal to the number of antenna port groups, and the multiple coding blocks can have different redundancy version identification numbers (IDs).

[0150] The process of step 301 can refer to Figure 2 The specific process of step 301 is not limited to the process of step 201 in the present application or the description of the existing technical solution. It should be noted that in step 301, various modulation methods in the prior art can be adopted, and the new modulation method proposed in this application: enhanced pi / 2-BPSK modulation method can also be adopted. The modulation signal generated by this modulation method can be referred to the above description and will not be repeated here.

[0151] In this application, the modulation symbols generated based on the transmission block are defined as data modulation symbols. The transmitting end can multiplex or map the data modulation symbols according to the rules on the signal block (block) corresponding to the DFT-s-OFDM symbol or the OFDM symbol to obtain signal A, and the signal A includes the data modulation symbols. Optionally, the transmitting end can also multiplex or map the data modulation symbols and the phase tracking reference signal (PTRS) according to the rules on the signal block (block) corresponding to the DFT-s-OFDM symbol or the OFDM symbol to obtain signal A, and the signal A includes the data modulation symbols and PTRS. It should be noted that the PTRS here is also a modulation symbol.

[0152] Furthermore, the transmitter may group the modulation symbols in signal A based on the number of modulation symbols (data and / or PTRS) that can be carried on each DFT-s-OFDM symbol or OFDM symbol to obtain one or more signals a. A signal a includes a modulation symbol corresponding to a DFT-s-OFDM symbol or a modulation symbol corresponding to an OFDM symbol.

[0153] The following processing is described below using a DFT-s-OFDM symbol or a modulation symbol included in an OFDM symbol as an example. The following processing can be performed on each DFT-s-OFDM symbol or an OFDM symbol.

[0154] Step 302: The transmitting end divides n modulation symbols into M groups of modulation symbols.

[0155] M is an integer greater than or equal to 2. Specifically, M is greater than or equal to the number of antenna port groups, and M is less than or equal to the number of antenna ports. It should be noted that the number of antenna ports here is not the number of antenna ports in one antenna port group, but the sum of the number of antenna ports (used for sending signals) in all antenna port groups.

[0156] Each group of modulation symbols is represented by C, and the M groups of modulation symbols are represented by C1, C2, C3, ..., C M express.

[0157] Step 302 can also be understood as: the transmitting end divides the signal B into M signals C (respectively C1, C2, C3, ..., C M ), signal B includes n modulation symbols, and the number of modulation symbols included in each signal C is less than n.

[0158] Signal B may be signal a, or signal B may be a portion of signal a. n is an integer greater than or equal to 2, and no other restrictions apply. The number of modulation symbols included in each modulation symbol group is less than n. Generally, a modulation symbol can only be assigned to one group. Alternatively, different groups may contain different modulation symbols, and the total number of modulation symbols included in M ​​modulation symbol groups is n.

[0159] Next, combine Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e , the number of groups M is introduced: M is greater than or equal to the number of antenna port groups, and M is less than or equal to the number of antenna ports (i.e., the sum of the number of antenna ports in all antenna port groups). The number of antenna ports included in an antenna port group can be the same or different. For example, the number of antenna ports included in an antenna port group can be 1, 2, 3, 4, or even more.

[0160] For example, as shown in 4a, there are two antenna ports, namely ant0 and ant1. Ant0 and ant1 are coherent or can perform coherent transmission. For example, ant0 and ant1 are on the same panel and are divided into an antenna port group. M is the same as the number of antenna ports, that is, M=2.

[0161] like Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e As shown, there are four antenna ports, namely ant0, ant1, ant2 and ant3. Ant0 and ant1 are coherent or can perform coherent transmission and are divided into one antenna port group. Ant2 and ant3 are coherent or can perform coherent transmission and are divided into another antenna port group. Antenna port groups are not coherent. For example, ant0 and ant1 are on one panel, and ant2 and ant3 are on another panel. Figure 4b and Figure 4d In , M is the same as the number of antenna ports, i.e., M = 4. Figure 4c In , M is the same as the number of antenna port groups, that is, M = 2. Figure 4e In the example, M=3.

[0162] Next, combine Figure 5a 、 Figure 5b and Figure 5c , which details several examples of dividing n modulation symbols into M groups of modulation symbols:

[0163] When n modulation symbols are divided into M groups of modulation symbols, the number of modulation symbols in each group can be the same or different. For example, when 9 modulation symbols are divided into 3 groups, the number of modulation symbols in each group can be 3; alternatively, the number of modulation symbols in the first group can be 1, the number of modulation symbols in the second group can be 3, and the number of modulation symbols in the third group can be 5.

[0164] In one example, when n modulation symbols are divided into M groups of modulation symbols, multiple modulation symbols that are consecutively positioned among the n modulation symbols can be grouped together. That is, a group of modulation symbols is consecutively positioned among the n modulation symbols. "Positional continuity" here can be understood as: no gaps in position, or uninterrupted position, or continuous modulation symbol indexes (indexes can also be called numbers), or no gaps or uninterrupted modulation symbol indexes.

[0165] like Figure 5b As shown, an example of grouping multiple modulation symbols with consecutive positions among n modulation symbols is introduced. Taking 10 modulation symbols (numbered 0-9) as an example, the 10 modulation symbols are divided into 2 groups, the modulation symbols numbered 0-4 are divided into the first group C1, and the modulation symbols numbered 5-9 are divided into the second group C2.

[0166] Figure 5b In the example, the number of modulation symbols in each group is the same. In actual applications, the number of modulation symbols in each group may also be different. For example, the modulation symbols numbered 0-3 are divided into a first group C1, and the modulation symbols numbered 4-9 are divided into a second group C2.

[0167] It can be further concluded that when multiple modulation symbols with consecutive positions among n modulation symbols are divided into a group, the modulation symbols at the first n / M positions of the n modulation symbols can be divided into the first group C1, the modulation symbols at the (n / M)+1th to 2n / Mth positions can be divided into the second group C2, the modulation symbols at the (2n / M)+1th to 3n / Mth positions can be divided into the third group C3,..., and the modulation symbols at the last n / M positions can be divided into the Mth group.

[0168] In one example, when n modulation symbols are divided into M groups of modulation symbols, multiple modulation symbols that are not consecutive in the n modulation symbols can be grouped together. This can also be understood as: any two adjacent (or consecutive) modulation symbols in any group of modulation symbols are not adjacent (or consecutive) in position among the n modulation symbols. Alternatively, any two adjacent (consecutive) modulation symbols in any group of modulation symbols have non-adjacent (or non-consecutive) modulation symbol indexes among the n modulation symbols.

[0169] like Figure 5aAs shown in the figure, an example of grouping multiple modulation symbols with discontinuous positions among n modulation symbols is introduced. Taking 10 modulation symbols (numbered 0-9) as an example, the 10 modulation symbols are divided into 2 groups, the modulation symbols numbered 0, 2, 4, 6, and 8 are divided into the first group C1, and the modulation symbols numbered 1, 3, 5, 7, and 9 are divided into the second group C2.

[0170] Depend on Figure 5a From the example, it can be concluded that when mapping modulation symbols to two groups: C1 and C2, the first modulation symbol among n modulation symbols is allocated to C1, the second modulation symbol is allocated to C2, and the third modulation symbol is allocated to C1. Similarly, the 2i+1th modulation symbol among n modulation symbols is allocated to C1, and the 2i+2th modulation symbol is allocated to C2, where i is greater than or equal to 0. This grouping method can be called a comb grouping method.

[0171] Figure 5a Taking 2 groups as an example, if the modulation symbols are divided into 3 groups: C1, C2, and C3, the 1st modulation symbol among the n modulation symbols is divided into C1, the 2nd modulation symbol is divided into C2, and the 3rd modulation symbol is divided into C3, and so on. The 3i+1th modulation symbol among the n modulation symbols is divided into C1, the 3i+2th modulation symbol is divided into C2, and the 3i+3th modulation symbol is divided into C3, where i is greater than or equal to 0.

[0172] In one example, when n modulation symbols are divided into M groups of modulation symbols, multiple modulation symbols whose positions are partially continuous and whose positions are partially discontinuous in the n modulation symbols can be divided into one group. That is, the positions of any group of modulation symbols in the n modulation symbols are partially connected and partially discontinuous. It can also be understood that: the positions of a part of adjacent (or continuous) modulation symbols in any group of modulation symbols are not adjacent (or discontinuous) in the n modulation symbols, and the positions of a part of adjacent (or continuous) modulation symbols in the n modulation symbols are adjacent (or continuous). Alternatively, the modulation symbol indexes of a part of adjacent (continuous) modulation symbols in any group of modulation symbols are not adjacent (or discontinuous) in the n modulation symbols, and the modulation symbol indexes of a part of adjacent (continuous) modulation symbols in the n modulation symbols are adjacent (or continuous).

[0173] like Figure 5c As shown in the figure, an example is introduced of grouping multiple modulation symbols, some of which are continuous and some of which are discontinuous, among n modulation symbols. For example, two modulation symbols are first grouped together, and then each group is grouped in a comb-like manner. For example, n modulation symbols are divided into two groups: C1 and C2. That is, the 4i+1 and 4i+2 modulation symbols of the n modulation symbols are grouped into C1, and the 4i+3 and 4i+4 modulation symbols are grouped into C2.

[0174] It can be further concluded that first, h consecutive modulation symbols are grouped, and then each group is grouped in a comb manner, where h is an integer greater than or equal to 2. If h = 1, then the above Figure 5a If h = n / M, then the above Figure 5b If h = 2, then the above Figure 5c .

[0175] The above-mentioned grouping unit h can be 2, or 3, or 4, or 8, etc. The values ​​of integer multiples of 2 such as 2, 4, 8, etc. are to ensure that when the modulation mode is pi / 2BPSK, after being divided into M groups, the phase change on adjacent symbols in each group satisfies the phase change characteristic of pi / 2. Therefore, it can be further defined that when the modulation mode adopted by the transmitting end is the existing pi / 2BPSK, the grouping unit h is greater than or equal to 2. When the modulation mode adopted by the transmitting end is the enhanced pi / 2BPSK provided in this application, the grouping unit h is greater than or equal to 1. When the modulation order adopted by the transmitting end is higher than the modulation order of pi / 2BPSK, the grouping unit h is greater than or equal to 1. Alternatively, in order to unify the signal processing flow under each modulation mode, the grouping unit h under all modulation modes can also be configured to be greater than or equal to 2. Alternatively, the grouping unit h under all modulation modes can also be configured to be equal to 1. At this time, pi / 2BPSK is the enhanced modulation mode described above.

[0176] It should be noted that the above descriptions of "dividing into the first group C1 (or into the first group C1)" and "dividing into the second group C2 (or into the second group C2)" are only examples of grouping, and the first group C1 and the second group C2 should not limit the order of grouping. In actual applications, the modulation symbols divided into the first group C1 can also be divided into the second group C2. The modulation symbols divided into the second group C2 can also be divided into the first group C1. For example, in Figure 5c In the example, the 4i+1th and 4i+2th modulation symbols among the n modulation symbols may be divided into the second group C2, and the 4i+3th and 4i+4th modulation symbols may be divided into the first group C1.

[0177] At step 301, an optional implementation is introduced to multiplex the PTRS with data modulation symbols on a DFT-s-OFDM or OFDM signal block. If this process is performed, the mth group of modulation symbols includes data modulation symbols and PTRS, and if this process is not performed, the mth group of modulation symbols includes data modulation symbols.

[0178] If a PTRS is configured in the current DFT-s-OFDM symbol or OFDM symbol, and the process of multiplexing the PTRS and the data modulation symbols on a signal block of the DFT-s-OFDM symbol or OFDM symbol is not performed before the division into M groups in step 302, optionally, after obtaining the mth group of modulation symbols in step 302, the pattern and multiplexing position of the PTRS within each group can be determined based on the PTRS configuration information and the related information of the division into M groups, thereby completing the multiplexing of the PTRS and the data modulation symbols. The updated mth group of modulation symbols then includes the data modulation symbols and the PTRS.

[0179] Optionally, other modulation symbols, such as modulation symbols corresponding to uplink control information, may be added to the mth group of modulation symbols. The updated mth group of modulation symbols then includes data modulation symbols and modulation symbols corresponding to uplink control signals, and optionally, PTRS.

[0180] Step 303: The transmitter performs a discrete Fourier transform (DFT) on the mth group of modulated symbols to obtain the mth group of DFT symbols. The DFT symbols may also be referred to as symbols or complex symbols.

[0181] It should be understood that the mth group of modulation symbols herein may be the mth group of modulation symbols obtained by dividing into M groups, or may be the "updated mth group of modulation symbols" described above. The mth group of modulation symbols includes: data modulation symbols, and optionally, also includes: modulation symbols corresponding to uplink control signals and / or PTRS.

[0182] The value of m is an integer from 1 to M; for example, m = 1, 2, 3, ..., M. If the mth group is considered as the group with index m, the index can also start from 0, then m = 0, 1, 2, 3, ..., M-1. In summary, the transmitter performs DFT on each group of modulation symbols separately.

[0183] Each group of DFT symbols is represented by D, and the M groups of DFT symbols are represented by D1, D2, D3, ..., D M express.

[0184] Step 303 can also be understood as: the sending end sends the mth signal C m Perform discrete Fourier transform DFT to obtain the mth signal D m The signal Cm includes the mth group of modulation symbols, and the signal D m Including the mth group of DFT symbols. The mth signal D m The dimension of the mth signal C m The dimensions are the same.

[0185] When performing the DFT on the mth group of modulation symbols, the size of the DFT used is the number of symbols in the mth group of modulation symbols, rather than the number of modulation symbols n. For example, if the number of modulation symbols in a group is Nex / 2, the number of DFT points (size) is Nex / 2. The DFT matches the number of modulation symbols in each group, reserving diversity space for subsequent frequency domain / spatial domain diversity. At the same time, it can reduce the dimension of the DFT, reducing the difficulty and complexity of the DFT. In addition, it should be noted that the mth group of modulation symbols can be the mth group of modulation symbols obtained by dividing into M groups, or it can be the "updated mth group of modulation symbols" introduced above.

[0186] The number of modulation symbols included in different groups of modulation symbols (ie, different signals C) is the same or different. Therefore, when performing DFT on the different groups of modulation symbols, the sizes of the DFTs used are the same or different.

[0187] Step 304: The transmitting end adds one or more preset symbols to the mth group of valid symbols to obtain the mth group of extended symbols.

[0188] The number of symbols after the mth group of extension is defined as Nex. Generally, Nex is less than or equal to the number of REs (or subcarriers) in the scheduling bandwidth. There is no limit on the size of Nex and the number of REs in the scheduling bandwidth.

[0189] It should be noted that if the DFT in step 303 is not performed, the valid symbols are the modulation symbols; if the DFT in step 303 is performed, the valid symbols are the symbols after the DFT.

[0190] The pre-set symbol can be 0 or any other symbol. For ease of description, adding one or more pre-set symbols is referred to as extension. This means the transmitter extends each set of valid symbols to obtain each set of extended symbols. Extension can also be understood as "mapping," meaning mapping the positions of valid signals.

[0191] Each group of expanded symbols is represented by E, and the symbols of M groups are represented by E1, E2, E3, ..., E M For example, the length of signal E is Nex.

[0192] If the DFT of step 303 is not performed, step 304 can also be understood as: the transmitting end performs DFT on the m-th signal C m Add one or more preset symbols (extension) to obtain the mth signal E m If the DFT of step 303 is performed, step 304 can also be understood as: the transmitting end performs DFT on the m-th signal C m Add one or more preset symbols (extension) to obtain the mth signal E m . mth signal Em The number of symbols included is Nex.

[0193] Next, combine Figure 6a 、 Figure 6b and Figure 6c , introducing several examples of adding one or more preset symbols to each group of valid symbols to obtain each group of extended Nex symbols. The following several extended examples all meet the characteristic 1: the position of any group of valid symbols in any group of extended symbols does not overlap with the position of another group of valid symbols in the other group of extended symbols. The non-overlapping here can also be replaced by different. A specific example of non-overlapping can be complementary, of course, it can also be non-complementary. Optionally, the position of the s group of modulation symbols corresponding to the g-th antenna port group in the s group of extended symbols does not overlap with the position of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols.

[0194] In one example, in the mth group of valid symbols, x preset symbols are added to every y valid symbols to obtain the mth group of extended symbols, where y is an integer greater than or equal to 1, and x is an integer greater than or equal to 1.

[0195] like Figure 6a As shown, the number of groups M is 2, the symbols in D1 occupy odd positions in E1, and the symbols in D2 occupy even positions in E2. Of course, the symbols in D1 can also occupy even positions in E1 and the symbols in D2 can occupy odd positions in E2.

[0196] It can also be understood that y is 1 and x is 1, that is, one preset symbol is added for every valid symbol. The position of one preset symbol in the first group among the expanded symbols of the first group is the position of one valid symbol in the second group among the expanded symbols of the second group. Similarly, the position of one preset symbol in the second group among the expanded symbols of the second group is the position of one valid symbol in the first group among the expanded symbols of the first group. In other words, the position of the valid symbols of the first group among the expanded symbols of the first group does not overlap with the position of the valid symbols of the second group among the expanded symbols of the second group. The non-overlapping here can also be replaced by different or complementary.

[0197] If the number of groups M is 3, an example is: y is 1, x is 2, that is, 2 preset symbols are added for every 1 valid symbol. The positions of the 2 consecutive preset symbols in the first group in the expanded symbols of the first group are respectively the positions of the 1 valid symbol in the second group in the expanded symbols of the second group and the position of the 1 valid symbol in the third group in the expanded symbols of the third group. Similarly, the positions of the 2 consecutive preset symbols in the second group in the expanded symbols of the second group are respectively the positions of the 1 valid symbol in the first group in the expanded symbols of the first group and the position of the 1 valid symbol in the third group in the expanded symbols of the third group. Similarly, the positions of the 2 consecutive preset symbols in the third group in the expanded symbols of the third group are respectively the positions of the 1 valid symbol in the first group in the expanded symbols of the first group and the position of the 1 valid symbol in the second group in the expanded symbols of the second group.

[0198] If the number of groups M is 4, one example is: y is 1 and x is 3, that is, 3 preset symbols are added for each valid symbol. The positions of the three consecutive preset symbols in each group in the expanded symbol group are the positions of the valid symbols in each of the other three groups in the expanded symbol group.

[0199] In summary, when the number of groups is M, one example is: y is 1 and x is M-1, that is, M-1 preset symbols are added for each valid symbol. The positions of the M-1 consecutive preset symbols in the mth group in the expanded symbols of the mth group are the positions of the valid symbols in each of the other M-1 groups in the expanded symbols of their respective groups.

[0200] If the number of groups M is 2, y is 2, and x is 2, that is, 2 preset symbols are added for every 2 valid symbols. The positions of the two consecutive preset symbols in the first group in the expanded symbols of the first group are the positions of the two consecutive valid symbols in the second group in the expanded symbols of the second group. Similarly, the positions of the two consecutive preset symbols in the second group in the expanded symbols of the second group are the positions of the two consecutive valid symbols in the first group in the expanded symbols of the first group. Similarly, the positions of the first group of valid symbols in the expanded symbols of the first group do not overlap with the positions of the second group of valid symbols in the expanded symbols of the second group. The term "non-overlapping" here can also be replaced by "different" or "complementary".

[0201] If the number of groups M is 3, y is 2, and x is 4, that is, 4 preset symbols are added for every 2 valid symbols. The positions of the 4 consecutive preset symbols in the first group in the expanded symbols of the first group are the positions of the 2 valid symbols in the second group in the expanded symbols of the second group and the positions of the 2 valid symbols in the third group in the expanded symbols of the third group. Similarly, the positions of the 4 consecutive preset symbols in the second group in the expanded symbols of the second group are the positions of the 2 valid symbols in the first group in the expanded symbols of the first group and the positions of the 2 valid symbols in the third group in the expanded symbols of the third group. The third group is similar and will not be repeated. Figure 6c As shown, D1 is at the 1st, 2nd, 7th, 8th, 13th, 14th... positions in E1, D2 is at the 3rd, 4th, 9th, 10th,... positions in E3, and D3 is at the 5th, 6th, 11th, 12th... positions in E3.

[0202] In summary, when the number of groups is M, one example is: y is 2, x is 2(M-1), that is, 2(M-1) preset symbols are added for every 2 valid symbols. The positions of the 2(M-1) consecutive preset symbols in the mth group in the expanded symbols of the mth group are the positions of the 2 valid symbols in each of the other M-1 groups in the expanded symbols of their respective groups.

[0203] We can further conclude that when the number of groups is M, x = y*(M-1). The positions of the y*(M-1) consecutive preset symbols in the mth group within the expanded symbols of the mth group are the positions of the y valid symbols in each of the other M-1 groups within the expanded symbols of their respective groups. In other words, x is an integer multiple of y. y is an integer greater than or equal to 1. In one example, y is the number of resource elements (REs) included in the resource block group (RBG).

[0204] It can also be concluded that:

[0205] In one example, the positions of the mth group of valid symbols in the mth group of symbols after expansion are discontinuous, which can also be understood as: the positions of any two adjacent symbols in the mth group of valid symbols in the mth group of symbols after expansion are discontinuous. Figure 6a shown.

[0206] In one example, the positions of the mth group of valid symbols in the mth group of symbols after expansion are continuous, which can also be understood as: the positions of any two adjacent symbols in the mth group of valid symbols in the mth group of symbols after expansion are adjacent. Figure 6b shown.

[0207] In one example, some positions of the mth group of valid symbols in the mth group of symbols after expansion are continuous, while some positions are discontinuous. This can also be understood as: some adjacent symbols in the mth group of valid symbols are adjacent in the mth group of symbols after expansion, while some adjacent symbols are discontinuous in the mth group of symbols after expansion. Figure 6c shown.

[0208] exist Figure 6b In the example, the number of groups M is 2, the symbols in D1 occupy the first half of E1, and the symbols in D2 occupy the second half of E2. Of course, the symbols in D1 can also occupy the second half of E1 and the symbols in D2 occupy the first half of E2.

[0209] It can also be understood that y is Nex / 2 and x is Nex / 2, that is, Nex / 2 preset symbols are added for every Nex / 2 valid symbols. The positions of the consecutive Nex / 2 preset symbols in the first group in the first group of expanded symbols are the positions of the Nex / 2 valid symbols in the second group in the second group of expanded symbols. Similarly, the positions of the consecutive Nex / 2 preset symbols in the second group in the second group of expanded symbols are the positions of the Nex / 2 valid symbols in the first group in the first group of expanded symbols. Similarly, the positions of the first group of valid symbols in the first group of expanded symbols do not overlap with the positions of the second group of valid symbols in the second group of expanded symbols, or are different, or are complementary.

[0210] Next, we will introduce the details of the above examples.

[0211] This application defines a resource element group REG, where one REG includes P REs, where P is an integer greater than or equal to 1. Figure 6a Can be seen as Figure 6c In the example, REG is used as the unit and P=1. Figure 6b Can be seen as Figure 6c In the example, RBG is used as a unit, and the number of RBs included in RBG is Q=(Nex / 12) / 2. Or, Figure 6b Can be seen as Figure 6c In the example with REG as the unit and P = Nex / 2, the relationship between the extended signal E and the unextended signal D can be expressed by the following formula: Q is the number of RBs contained in the RBG, p = Q*12, that is, P is an integer multiple of 12, and the multiple is Q.

[0212] The above summary shows that when the number of groups is M, x = y*(M-1). The positions of the y*(M-1) consecutive preset symbols in the mth group within the expanded symbols of the mth group are the positions of the y valid symbols in each of the other M-1 groups within the expanded symbols of their respective groups. In this example, P = y; the 2 in mod(floor(k / P),2) and floor(k / P) / 2 can be interpreted as x+y.

[0213] When expanding, the following formula 3 can be satisfied:

[0214]

[0215] Where k is the number of each symbol in the extended symbols, k = 0, ..., Nex-1, M is the number of groups, e i represents the symbol after the expansion of group i, d i represents the i-th group of valid symbols (symbols after DFT or modulation symbols). is the index of the symbol in each set of valid symbols. When k starts at 1, replace floor(k / P) with ceil(k / P)-1 and mod(k,P) with mod(k-1,P)+1 in the above formula.

[0216] In addition, the REG size can be adaptively selected based on factors such as the channel. For example, when the distance between the terminal and network equipment is long, the SNR is low, and coverage is the primary concern, P = 1 can be selected to achieve RE-level inter-group interleaving mapping. For another example, when the channel is relatively flat and frequency selectivity is weak, P = 48 can be selected to achieve RBG-level interleaving mapping.

[0217] In addition, the extension mode can be indicated by signaling. Alternatively, the extension mode can also be pre-agreed. Alternatively, the extension mode is associated with the subband-level TPMI, channel quality information (CQI), etc. fed back by the UE. For example, the greater the difference in TPMI or CQI on multiple subbands, the smaller the value of P; the smaller the difference in TPMI or CQI on multiple subbands, the larger the value of P; the difference in TPMI or CQI is negatively correlated with the value of P. Alternatively, the extension mode is implicitly indicated by the modulation order. For example, when the modulation order is equal to or lower than QPSK, REG = 1; when the modulation order is higher than or equal to 64QAM, REG = 12, so that the PTRS block can be mapped to a continuous frequency domain resource. Alternatively, the extended mode is indicated by a combination of explicit signaling and implicit mode, such as RRC or DCI indicating the value of REG; when the modulation mode is higher than QPSK, the explicit signaling has a higher priority, that is, the REG indicated by the explicit signaling shall prevail; when the modulation mode is equal to or lower than QPSK, the explicit signaling is invalid at this time, and REG=1 shall prevail.

[0218] In the examples described above, the value of y in each group is the same. In actual applications, the values ​​of y in different groups can also be different, and the values ​​of x in different groups can also be different. Let's continue with the following:

[0219] For example, if M is 2, 10 preset symbols are added for every 5 valid symbols in the first group, and 5 preset symbols are added for every 10 valid symbols in the second group. The positions of the 5 consecutive valid symbols in the first group in the expanded symbol group are the positions of the 10 consecutive preset symbols in the second group in the expanded symbol group.

[0220] Based on this example, we can conclude that in the first group, x is an integer multiple of y, and in the second group, y is an integer multiple of x. Furthermore, the number of y multiples of x in the second group is the same as the number of x multiples of y in the first group.

[0221] In this application, there is no limitation on the method of adding one or more preset symbols to each group of symbols to obtain each group of expanded Nex symbols, as long as the characteristic 1 introduced above is met.

[0222] Next, we introduce several examples of the above extensions. Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d as well as Figure 4e Application in.

[0223] exist Figure 4a and Figure 4cIn the example, the number of groups M is 2, and the two groups are jointly expanded. The expansion method adopted by the two groups can be any of the expansion methods with M being 2 introduced above, as long as the above characteristic 1 is satisfied, that is, the position of D1 in E1 and the position of D2 in E2 do not overlap, are different, or are complementary.

[0224] exist Figure 4b In [1], the number of groups M is 4, and each antenna port group is expanded independently, with the two antenna port groups being independent of each other. Any antenna port group can use any of the expansion methods described above where M is 2. Each antenna port group can satisfy Property 1 independently, rather than requiring both antenna port groups to satisfy Property 1 as a whole. That is, the position of D1 in E1 and the position of D2 in E2 must not overlap, be different, or be complementary. The position of D3 in E3 and the position of D4 in E4 must not overlap, be different, or be complementary.

[0225] exist Figure 4d In the example, the number of groups M is 4, and these four groups are jointly expanded. The expansion method used for these four groups of signals can be any of the expansion methods described above where M is 4, as long as these four groups of signals meet the above characteristic 1. That is, the position of D1 in E1 does not overlap with, is different from, or is complementary to the positions of the other three signals D in signal E; the position of D2 in E3 does not overlap with, is different from, or is complementary to the positions of the other three signals D in signal E; the position of D3 in E3 does not overlap with, is different from, or is complementary to the positions of the other three signals D in signal E; and the position of D4 in E4 does not overlap with, is different from, or is complementary to the positions of the other three signals D in signal E.

[0226] exist Figure 4e In this example, the number of groups M is 3, and these three groups are jointly expanded. The expansion method used for these three groups of signals can be any of the expansion methods described above where M is 3, as long as these three groups of signals meet the above characteristic 1. That is, the position of D1 in E1 does not overlap with, is different from, or is complementary to the position of D2 in E2 and the position of D3 in E3. The position of D2 in E2 does not overlap with, is different from, or is complementary to the position of D1 in E1 and the position of D3 in E3. The position of D3 in E3 does not overlap with, is different from, or is complementary to the position of D1 in E1 and the position of D2 in E2.

[0227] The above extension of different groups of valid symbols allows the valid symbols of different groups to be positioned non-overlapping, complementary, or different in the extended symbols. This allows the valid symbols to be mapped to different subcarriers during subsequent subcarrier mapping, thus achieving frequency domain diversity.

[0228] In addition, combined Figure 4dAs an example, taking two antenna port groups, one antenna port group corresponds to two groups of valid symbols, and these four groups of valid symbols are jointly extended as an example, another extension method is introduced.

[0229] This spreading method meets Property 2: For one antenna port group, the position of the first group of valid symbols in the first group of spread signals is the same as the position of the second group of valid symbols in the second group of spread signals. For two antenna port groups, the position of the first group of valid symbols corresponding to the first antenna port group in the first group of spread signals corresponding to the first antenna port group and the position of the first group of valid symbols corresponding to the second antenna port group in the first group of spread signals corresponding to the second antenna port group do not overlap, are different, or are complementary.

[0230] It can also be understood that the signals belonging to the same antenna port group in these four groups use the same spreading method, while signals belonging to different antenna port groups can use any of the spreading methods described above, as long as the above characteristic 1 is satisfied between the antenna port groups. That is, the way D1 is spread to E1 is the same as the way D2 is spread to E2, and the way D3 is spread to E3 is the same as the way D4 is spread to E4. It can also be understood that the position of D1 in E1 is the same as the position of D2 in E2. The position of D3 in E3 is the same as the position of D4 in E4. Furthermore, the position of D1 in E1 and the position of D3 in E3 do not overlap, are different, or are complementary.

[0231] For example, in Figure 4d In the example, D1 is in the first half of E1, and D2 is also in the first half of E2. D3 is in the second half of E3, and D4 is also in the second half of E4. In practical applications, D1 can also be in the second half of E1, and D2 can also be in the second half of E2. D3 can be in the first half of E3, and D4 can also be in the first half of E4. For example, you can combine Figure 6b Let me explain in more detail: Figure 4d In the example, D1 is at position E1, and D2 is also at position E2, which is equivalent to Figure 6b D1 in the figure is at the position of E1. Figure 4d D3 is at E3, and D4 is also at E4, which is equivalent to Figure 6b D2 in the equation is at the position of E2. For another example, D1 is at the even position of E1, D2 is at the even position of E2, D3 is at the odd position of E3, and D4 is at the odd position of E4.

[0232] exist Figure 4eIn another scenario, the signals belonging to the same antenna port group in these three groups use the same spreading method, while signals belonging to different antenna port groups can use any of the spreading methods described above, as long as the above characteristic 1 is satisfied between the antenna port groups. That is, the method for extending D1 to E1 is the same as the method for extending D2 to E2. It can also be understood that the position of D1 in E1 is the same as the position of D2 in E2. The position of D3 in E3 does not overlap with, is complementary to, or is different from the position of D1 in E1. For example, D1 is in the first half of E1, and D2 is also in the first half of E2. D3 is in the second half of E3. Alternatively, D1 is in an even position in E1, D2 is in an even position in E2, and D3 is in an odd position in E3.

[0233] Based on the above example, if the number of antenna port groups is not limited, nor is the number of groups corresponding to an antenna port group, characteristic 2 can be updated as follows: for an antenna port group, the position of each group of valid symbols in the extended signal of each group is the same, that is, in an antenna port group, the position of any group of modulation symbols in any extended symbol group is the same as the position of another group of modulation symbols in the extended symbol group. For different antenna ports, the position of the first group of valid symbols corresponding to any antenna port group in the first group of extended signals corresponding to any antenna port group does not overlap, is different from, or is complementary to the position of the first group of valid symbols corresponding to another antenna port group in the first group of extended signals corresponding to another antenna port group. Alternatively, the position of the s group of modulation symbols corresponding to the gth antenna port group in the s group of extended symbols does not overlap, is different from, or is complementary to the position of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols.

[0234] The above extension of valid symbols for different groups allows valid symbols for different antenna port groups to be positioned non-overlapping, complementary, or different in the extended symbols. This allows subsequent subcarrier mapping to map valid symbols to different subcarriers, achieving frequency domain diversity for different antenna port groups.

[0235] Step 305: The transmitter performs (second-stage) precoding on the s groups of expanded symbols corresponding to the g-th antenna port group to obtain symbols corresponding to each antenna port in the g-th antenna port group. In the second-stage precoding, the dimension of the precoding matrix used by the g-th antenna port group is related to s and the number of antenna ports included in the g-th antenna port group, where s is an integer greater than or equal to 1 and less than or equal to M, and g is an integer greater than or equal to 1. If g represents a group index, g may also start at 0. That is, the number of input streams for precoding is s, and the number of output streams is the number of antenna ports included in an antenna port group, for example, 2 or 4.

[0236] It should be noted that the transmitting end can perform precoding once or twice. For the sake of distinction, the precoding in step 305 can be referred to as the second-level precoding. Another precoding is also introduced below. The other precoding introduced below is called the first-level precoding. The first-level precoding is used to distribute the extended symbols among multiple antenna ports or multiple antenna port groups, that is, to select an antenna port or antenna port group for each group of extended symbols. The first and second levels here are only for distinction and should not limit the present application. The second-level precoding is related to the determination of the transmitted signal of each antenna port in the antenna port group.

[0237] The number s of groups corresponding to different antenna port groups is the same or different, for example, s is 1, 2, 3, 4, etc.

[0238] The symbol corresponding to each antenna port obtained after the second-stage precoding is represented by F. Step 305 can also be understood as: the transmitting end performs the second-stage precoding on the s-path signal E corresponding to the g-th antenna port group to obtain a signal F corresponding to each antenna port in the g-th antenna port group.

[0239] exist Figure 4a In the dual-antenna port, the number of input streams s of the second-level precoding is 2, and the number of output streams is 2.

[0240] exist Figure 4b In the example, there are four antenna ports, the number of input streams s for the second-level precoding is 2, and the number of output streams is 2.

[0241] exist Figure 4c In the example, there are four antenna ports, the number of input streams s for the second-level precoding is 1, and the number of output streams is 2.

[0242] exist Figure 4d In the example, there are four antenna ports, the number of input streams s for the second-level precoding is 2, and the number of output streams is 2.

[0243] exist Figure 4e In the example, for four antenna ports, the number of input streams s for the second-level precoding of one antenna port group is 2, and the number of output streams is 2; the number of input streams s for the second-level precoding of another antenna port group is 1, and the number of output streams is 2.

[0244] The above introduction Figure 4a In , ant0 and ant1 have coherence or can perform coherent transmission and are divided into one antenna port group. Figure 4b and Figure 4c and Figure 4d and Figure 4eIn this example, ant0 and ant1 are coherent or capable of coherent transmission and are grouped into one antenna port group. Antenna port groups are also coherent or capable of coherent transmission and are grouped into another antenna port group. Antenna port groups are independent of each other. For example, ant0 and ant1 are on one panel, and ant2 and ant3 are on another panel.

[0245] Two antenna ports in an antenna port group can be linked via the second-level precoding. However, since antenna port groups are independent of each other, antenna ports in different antenna port groups cannot be linked via the second-level precoding.

[0246] For example, without including the first level precoding, Figure 4a 、 Figure 4b and Figure 4d In the figure, the two expanded signals E1 and E2 are mapped to antenna ports ant0 and ant1 through a 2*2 precoding matrix, or the two expanded signals E3 and E4 are mapped to antenna ports ant2 and ant3 through a 2*2 precoding matrix. Figure 4a 、 Figure 4c and Figure 4d In [1], the 2*2 precoding matrix used by each antenna port group is the dual-stream to dual-antenna precoding matrix, which can be used but is not limited to the precoding matrix of group D described above. The precoding matrices used by different antenna port groups can be the same or different.

[0247] exist Figure 4c In the case where the first level precoding is not included, the two expanded signals E1 and E2 need to pass through a 2*1 precoding matrix to map the signal E1 to antenna ports ant0 and ant1, and to map the signal E2 to antenna ports ant2 and ant3. Figure 4c The 2*1 precoding matrix used in the example is a single-stream to dual-antenna precoding matrix. It can use, but is not limited to, the precoding matrix of Group A described above. The precoding matrices used by different antenna port groups can be the same or different. For example, antenna ports ant0 and ant1 use the precoding matrix indexed 1 in Group A, while antenna ports ant2 and ant3 use the precoding matrix indexed 2 in Group A. Alternatively, antenna ports ant0 and ant1 use the precoding matrix indexed 1 in Group A, while antenna ports ant2 and ant3 use the precoding matrix indexed 1 in Group A.

[0248] exist Figure 4eIn the embodiment, without including the first level precoding, the two expanded signals E1 and E2 are mapped to the antenna ports ant0 and ant1 through a 2*2 precoding matrix, and the one expanded signal E3 is mapped to the antenna ports ant2 and ant3 through a 2*1 precoding matrix.

[0249] After precoding, the signal has been expanded to achieve frequency domain diversity. Subsequently, by dividing and selecting coherent antenna port groups, this frequency domain diversity can be further converted into antenna port diversity, where different frequency domain resources correspond to different antenna port groups. For example, in Formula 3 above, when P = 1, the frequency domain resources occupied by the two antenna port groups exhibit a comb-like characteristic, with one antenna port group occupying even-numbered subcarriers within the scheduling bandwidth and the other antenna port group occupying odd-numbered subcarriers within the scheduling bandwidth.

[0250] Next, the process of determining the precoding matrix for the second-level precoding at the transmitting end is described in detail:

[0251] The transmitting end may receive indication information used to determine a precoding matrix. For example, the indication information may be received from the receiving end, or from a device other than the receiving end. When the transmitting end is a terminal, the indication information may be sent to the terminal by radio resource control (RRC), medium access control (MAC), downlink control information (DCI), or the like.

[0252] In one example, the indication information is used to indicate an index of a precoding matrix, for example, the indication information includes a sounding reference signal resource index (SRI). The receiving end determines the precoding matrix according to the SRI.

[0253] In one example, the indication information includes: a precoding matrix index, and the precoding matrix index is used to indicate a precoding matrix in a precoding matrix set, and the precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission. In the present application, the set can also be replaced by a group or a table. The transmitting end uses the precoding matrix corresponding to the precoding matrix index included in the indication information as the precoding matrix for precoding in this application. In this example, the precoding matrix for diversity transmission and the precoding matrix for non-diversity transmission are jointly indexed. In this way, the method only needs to indicate the index of the precoding matrix, and the transmitting end can find the corresponding precoding matrix. This indication method is simple and accurate. The precoding matrix index in the present application can be: transmitting precoding matrix index (TPMI).

[0254] In one example, the indication information includes a precoding matrix index and an indication of whether diversity transmission is to be performed. In this example, the precoding matrix used for diversity transmission and the precoding matrix used for non-diversity transmission are independently indexed, and may have the same index number. Therefore, the indication information can further include an indication of whether diversity transmission is to be performed. In this way, when the transmitting end determines to perform diversity transmission, it can search the precoding matrix corresponding to the precoding matrix index in the precoding matrix used for diversity transmission, rather than mistakenly searching the precoding matrix in the precoding matrix used for non-diversity transmission.

[0255] In one example, the indication of diversity transmission may be a display indication, for example, the indication of diversity transmission occupies 1 bit, for example, when 1 bit is 1, it indicates diversity transmission, and when 1 bit is 0, it indicates non-diversity transmission.

[0256] In one example, diversity transmission can be associated with a transmit waveform. For example, an OFDM waveform is associated with diversity transmission, and a DFT-s-OFDM waveform is associated with non-diversity transmission. The indication of diversity transmission can then be: an indication for indicating a transmit waveform. For example, when the indication of diversity transmission indicates an OFDM waveform, the transmitter does not perform diversity transmission and searches for a precoding matrix corresponding to a precoding matrix index in a precoding matrix used for non-diversity transmission. When the indication of diversity transmission indicates a DFT-s-OFDM waveform, the transmitter performs diversity transmission and searches for a precoding matrix corresponding to a precoding matrix index in a precoding matrix used for diversity transmission.

[0257] In one example, under the constraint of the total transmit power of a single antenna port, the power of the vacant resources on the same antenna port can be used to enhance the power of the non-zero data on the antenna port. Therefore, the data power boost value (also called power boosting value) can be used to indicate whether to perform diversity transmission. The transmitting end can determine whether to perform diversity transmission based on the data power boost value (or power boosting value) indicated in the indication information, and then determine the precoding matrix. For example, a threshold is set. When the data power boost value (or power boosting value) is greater than or equal to the threshold, diversity transmission is performed. When it is less than or equal to the threshold, diversity transmission is not performed. The threshold can be, for example, 0dB, 1dB, etc. For example, when the data power boost value (or power boosting value) is 0dB, the transmitting end does not perform diversity transmission. When the data power boost value (or power boosting value) is greater than 0dB, the transmitting end performs diversity transmission.

[0258] In one example, diversity transmission can be associated with the signal-to-noise ratio (SNR). For example, when the SNR is greater than or equal to a set threshold, diversity transmission is performed, and when the SNR is less than or equal to the set threshold, diversity transmission is not performed. The indication of diversity transmission can then be: an indication for indicating the SNR value. The transmitting end performs diversity transmission when it determines that the SNR is greater than or equal to the set threshold; when it determines that the SNR is less than or equal to the set threshold, diversity transmission is not performed, thereby determining the precoding matrix. The threshold can be specified by the protocol or negotiated between the transmitting end and the receiving end.

[0259] In one example, diversity transmission can be associated with a scheduling modulation and coding scheme (MCS). It is stipulated that some modulation modes perform diversity transmission, while some modulation modes do not. For example, when the modulation mode indicated by the MCS is pi / 2BPSK, diversity transmission is performed, otherwise diversity transmission is not performed; for another example, when the modulation mode indicated by the MCS is pi / 2BPSK or QPSK, diversity transmission is performed, otherwise diversity transmission is not performed. For another example, MCS is usually a numerical value, and the modulation mode is indicated by the numerical value. For example, when the MCS is less than a set threshold, diversity transmission is performed, otherwise diversity transmission is not performed.

[0260] In one example, the indication information includes a precoding matrix index and a precoding matrix set identifier, wherein the precoding matrices in the identified precoding matrix set are used for diversity transmission. In this way, the transmitting end can search for the precoding matrix corresponding to the precoding matrix index in the identified precoding matrix set.

[0261] In addition, for the device sending the indication information, it can perform channel estimation, traverse all allowed precoding matrices in units of sub-band or on the full band, select the precoding matrix corresponding to the lowest demodulation threshold value (or equivalently the highest SNR), and send the index of the precoding matrix to the sending end.

[0262] The above description describes that the transmitting end receives indication information sent by the receiving end or other devices to determine the precoding matrix. In another example, the transmitting end may also determine the precoding matrix itself and send indication information for determining the precoding matrix to the receiving end.

[0263] When indicating the precoding matrix index, different antenna port groups can be indicated separately. For example, the TPMI of an antenna port group 0 {ant0, ant1} is: TPMI0 = {T 0，0 , T 0，1 ,…,T 0，i , ...}. The TPMI of another antenna port group 1 {ant2, ant3} is: TPMI1 = {T 1，0 , T 1，1 ,…,T 1，j , ...}. Where i and j are subband numbers (indexes). 0 <= i <= N sb0 -1,0<=j<=N sb1 -1,N sb0 and N sb1 are the number of subbands divided on the scheduling bandwidth of the two antenna port groups, which can be equal or unequal. sb0 =1, or N sb1 =1, the TMPI on the corresponding antenna port group is full-band TPMI. 0，i The 0 in is the index (number) of the antenna port group, that is, the first value in the subscript of T is the index (number) of the antenna port group, and the second value in the subscript is the subband number (index).

[0264] Additionally, the precoding matrices for multiple antenna port groups can be combined into a single precoding matrix. A single precoding matrix index can be used to indicate the precoding matrices corresponding to each of the multiple antenna port groups. For example, if two antenna port groups are combined into a single matrix, and each antenna port group uses a 2x2 precoding matrix, the resulting combined matrix will have a size of 4x4.

[0265] For example, an overall precoding matrix is:

[0266]

[0267] or,

[0268]

[0269] Step 306: The transmitting end sends the symbol corresponding to each antenna port.

[0270] For example, the transmitting end may first perform a first processing on the symbols corresponding to each antenna port before transmitting. The first processing may also include, but is not limited to, subcarrier mapping, inverse discrete Fourier transform (IFFT), inverse fast Fourier transform (IFFT), adding a cyclic prefix (CP), power adjustment, etc. These processing processes can refer to the existing processing processes and will not be described in detail.

[0271] During subcarrier mapping, the transmitter maps the symbols corresponding to each antenna port to the subcarriers corresponding to that antenna port. The subcarriers corresponding to the antenna port are the subcarriers used by that antenna port to transmit the symbols in step 306. The subcarriers corresponding to any two antenna port groups can be the same, different, completely overlapping, or partially overlapping. The symbols in step 306 include valid signals and invalid signals. Valid signals are signals corresponding to modulation symbols, while wireless signals are signals corresponding to preset symbols added during the expansion process.

[0272] For example, in Figure 4a In the example, the valid symbol D1 is at the even position in E1 and the valid symbol D2 is at the odd position in E2. Then the valid symbols in E1 occupy the even subcarriers and the valid symbols in E2 occupy the odd subcarriers. When the precoding matrix in step 305 is When , the valid signal in the signal sent by antenna port ant0 occupies the even subcarriers in the scheduling bandwidth, and the valid signal in the signal sent by antenna port ant1 occupies the even subcarriers in the scheduling bandwidth.

[0273] During the extension, the position of the s groups of modulation symbols corresponding to the g-th antenna port group in the symbols after the extension of the s groups does not overlap with the position of at least one group of modulation symbols corresponding to any other antenna port group in the symbols after the extension of the at least one group. Therefore, it can be guaranteed that the intersection of the subcarrier sets that transmit valid signals on any two antenna port groups is an empty set, thereby achieving diversity transmission. In addition, by mapping multiple modulation symbols to multiple groups and interleaving between groups, the same code block can be mapped to different groups, and then mapped to different frequency domain resources or different antennas, thereby achieving more robust and stable decoding performance. Furthermore, through precoding, the diversity in the frequency domain can be converted into diversity in the antenna, and simultaneous diversity in the spatial and frequency domains can be achieved, thereby improving the diversity gain. In addition, the precoding between different antenna port groups is independent of each other and does not affect each other. While utilizing the incoherent characteristics between antenna ports to ensure performance, it reduces the precoding dimension and reduces the processing complexity of the transmitting end.

[0274] Next, we will introduce the first level precoding related content:

[0275] The above step 305 introduces the process of the second-level precoding, and the second-level precoding of step 305 is used to implement the mapping of the extended symbols to different antenna ports. Optionally, after step 304 and before the precoding of step 305, the first-level precoding of v groups of extended symbols can also be performed. Among them, the size of the precoding matrix used in the first-level precoding is v*v. The elements in the precoding matrix used in the first-level precoding are 0 and / or 1. In one example, v=M, and in another example, v is the number of antenna ports included in an antenna port group. The first-level precoding is used to implement the selection of the antenna port group, or to implement the selection of the antenna port. It can also be understood that after step 304 and before the precoding of step 305, the transmitting end determines the antenna port or antenna port group corresponding to each group of extended symbols.

[0276] For example, Figure 4a and Figure 4b In the first stage precoding, the antenna port selection is realized. Figure 4c 、 Figure 4d and Figure 4e In the first stage precoding, the antenna port group selection is realized. Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e The following precoding matrix for the first level precoding and the precoding matrix for the second level precoding are merely examples and should not limit the present application.

[0277] For example, in Figure 4a In the case where the first level precoding is not performed, when the precoding matrix of the second level precoding is When E1 corresponds to F1, that is, E1 is mapped to antenna port ant0; E2 corresponds to F2, that is, E2 is mapped to antenna port ant1. When the first level precoding is performed, if the precoding matrix of the first level precoding is Then E1'=E1, E2'=E2, E1 is still mapped to antenna port ant0; E2 is mapped to antenna port ant1. If the precoding matrix of the first level precoding is Then E1′=E2, E2′=E1, that is, E1 is mapped to the antenna port ant1, and E2 is mapped to the antenna port ant0.

[0278] in addition, Figure 4aThe precoding matrix of the first level precoding in also realizes the exchange of effective resources of different antenna ports. The position of the effective symbol D1 in E1 is different from the position of the effective symbol D2 in E2. Then, when performing frequency domain resource (subcarrier) mapping, the effective symbols in E1 and the effective symbols in E2 occupy different frequency domain resources. If the effective symbol D1 is in an even position in E1 and the effective symbol D2 is in an odd position in E2, the effective symbols in E1 occupy even subcarriers and the effective symbols in E2 occupy odd subcarriers. When the precoding matrix of the second level precoding is When the first level precoding is not performed, the effective resources occupied by the signal sent on the antenna port ant0 are even subcarriers, and the effective resources occupied by the signal sent on the antenna port ant1 are odd subcarriers. When the precoding matrix of the second level precoding is When the first level precoding is performed, when the precoding matrix of the first level precoding is When , the effective resources occupied by the signal sent on antenna port 0 are even subcarriers, and the effective resources occupied by the signal sent on antenna port 1 are odd subcarriers; when the precoding matrix of the first level precoding is When , the effective resources occupied by the signal sent on antenna port 0 are odd subcarriers, and the effective resources occupied by the signal sent on antenna port 1 are even subcarriers, that is, the exchange of effective resources of different antenna ports is achieved through the first-level precoding.

[0279] exist Figure 4b There are two antenna port groups, each of which can refer to Figure 4a Description, that is Figure 4b Each antenna port group in is similar to Figure 4a , rather than considering the two antenna port groups as a whole. Figure 4b The precoding matrix of the first level precoding in is a 2*2 matrix instead of a 4*4 matrix.

[0280] exist Figure 4c In the first level precoding, the antenna port group selection can be realized. The principle is the same as Figure 4a The introduction is similar. If the precoding matrix of the first level precoding is Then E1'=E1, E2'=E2, that is, E1 is mapped to the first antenna port group (ant0 and ant1); E2 is mapped to the second antenna port group (ant2 and ant3). If the precoding matrix of the first level precoding is Then E1′=E2, E2′=E1, that is, E1 is mapped to the second antenna port group (ant2 and ant3), and E2 is mapped to the first antenna port group (ant0 and ant1).

[0281] exist Figure 4dIn the first level precoding, the antenna port group selection can be realized. The principle is the same as Figure 4a similar.

[0282] When the precoding matrix of the first level precoding is the unit matrix, then E'1 = E1, E'2 = E2, E'3 = E3, E'4 = E4. When the precoding matrix of the first level precoding is When , E'1=E4, E'2=E3, E'3=E2, E'4=E1.

[0283] exist Figure 4e In the first level precoding matrix, the antenna port group selection can be realized. The principle is the same as Figure 4a similar.

[0284] When the precoding matrix of the first-level precoding is the unit matrix, ( Figure 4e (not shown) E1 and E2 correspond to the first antenna port group (ant0 and ant1), and E3 corresponds to the second antenna port group (ant2 and ant3).

[0285] When the precoding matrix of the first-level precoding is Then E'1=E3, E'2=E2, E'3=E1.

[0286] When the precoding matrix of the first-level precoding is Then E'1=E3, E'2=E1, E'3=E2.

[0287] Based on the examples described above, when selecting a precoding matrix for the first-level precoding, in order to implement antenna port swapping, the precoding matrix for the first-level precoding needs to meet the following characteristics 3:

[0288] The i-th group of extended symbols is sent on the j-th antenna port, then the j-th element of the i-th row of the first-level precoding matrix is ​​non-zero, and the other elements or blocks of the i-th row are 0.

[0289] To achieve antenna port group switching, the precoding matrix of the first-level precoding needs to meet the following characteristics4:

[0290] The i-th group of extended symbols is sent on the g-th antenna port group, then the block with coordinates (i, j) of the first-level precoding matrix is ​​a non-zero matrix, and the other blocks with row coordinates i are 0 matrices, and the unit of coordinates (i, j) is block, that is, coordinates (i, j) are block coordinates.

[0291] For example, the precoding matrix of the first level precoding is a block diagonal matrix (or called a partitioned block diagonal matrix) or a block anti-diagonal matrix (or called an anti-block diagonal matrix).

[0292] The blocks of diagonal elements or the blocks of anti-diagonal elements in the block diagonal matrix are unit matrices whose size is the number of antenna ports in the antenna port group.

[0293] The blocks in the block anti-diagonal matrix are unit matrices whose size is the number of antenna ports in the antenna port group.

[0294] As described above, the above solution achieves frequency and spatial diversity by occupying a portion of frequency domain resources when transmitting valid signals on different antenna ports, with at least two antenna ports occupying different resources when transmitting valid signals, thereby improving signal demodulation capabilities. Since valid signal transmission only occupies a portion of the resources, the number of valid resources used for valid signal transmission is reduced compared to non-diversity transmission, significantly reducing the number of transmission blocks. Due to the significant gain of diversity, the overall transmission capacity may be improved compared to existing technologies. Since the number of resources occupied by diversity is reduced, the scheduling modulation and coding scheme (MCS) must also be adjusted synchronously to match the transmission capacity of non-diversity transmission. For example, when the number of resources occupied by an antenna port is halved, the corresponding spectral efficiency of the MCS must be doubled, that is, Qm*CR is doubled, where Qm is the modulation order, which can take values ​​of 1, 2, 4, 6, 8, 10, etc., and CR is the coding rate, which can take values ​​greater than 0 and less than 1.

[0295] In addition, the present application can also be used in conjunction with other methods to improve coverage. For example, when the modulation method is enhanced pi / 2BPSK, the transmission signal corresponding to this modulation method has the characteristic of segmented conjugate symmetry. Before expanding each group of modulation symbols, a "truncation filtering" (it should be noted that truncation filtering is divided into two parts: truncation and filtering) process is performed. The receiving end improves the receiver according to the rules of expansion and truncation filtering, and then recovers the information. Compared with the existing technology (frequency domain spectral shaping R15: FDSS, frequency domain spectral shaping), this method has higher spectral efficiency when ensuring data demodulation performance. Or under the same spectral effect, it has a lower code rate and improves coverage. The following is a detailed introduction to the "truncation filtering" process.

[0296] Optionally, after the transmitting end performs the discrete Fourier transform (DFT) in step 303 and before performing the precoding in step 305, the transmitting end may further perform the following “truncation” process for each group of DFT symbols:

[0297] The first L1 and / or last L2 symbols in the mth group of valid signals (symbols or modulation symbols after DFT) are filtered out (or discarded, or not mapped to subcarriers). L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1. The value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor. Optionally, the absolute value of the difference between L1 and L2 is less than a set threshold, and the set threshold is 1 or 2. The ratio of the number of remaining symbols in the mth group of valid signals (symbols or modulation symbols after DFT) to the number of the mth group of valid signals (symbols or modulation symbols after DFT) is equal to the truncation factor, and the truncation factor is less than 1 and greater than 0. Subsequently, the "remaining symbols in the mth group of valid signals" are used as the "mth group of valid signals" to perform subsequent processes.

[0298] The “truncation” process can be performed at any stage before precoding, usually after the DFT in step 303 and before the expansion in step 304 .

[0299] The truncation factor may be indicated by the receiving end, for example, the transmitting end receives indication information, the indication information is used to indicate the truncation factor. The truncation factor may also be specified by the protocol without the need for indication by the receiving end.

[0300] After the "truncation" operation is performed, the "filtering" operation can be performed. The "filtering" process can refer to the existing technology and will not be described in detail. For example, in one possible implementation, filtering is achieved through frequency domain weighting. Figure 7 As shown, a schematic diagram of truncation filtering is provided, and the scheduling bandwidth is greater than the virtual bandwidth.

[0301] Assume that the scheduling bandwidth is N RE0 or N RB0 , virtual bandwidth N REi or N RBi In one possible implementation, the transmitter can calculate the virtual bandwidth based on the scheduled bandwidth and the truncation factor. For example, the truncation factor is f tc , then the virtual bandwidth can be expressed as: N REi = Round(N RE0 / f tc ) or N RBi = Round(N RB0 / f tc ), where rounding refers to rounding up, rounding down, or rounding to the nearest integer.

[0302] If the "truncation" process is not performed: In step 301 above, the transmitter calculates the transport block size based on the number of resources included in the scheduled bandwidth, and generates source bits based on this transport block size for encoding and modulation. If the "truncation" process is performed: In step 301 above, the transmitter calculates the transport block size based on the number of resources included in the virtual bandwidth, and generates source bits based on this transport block size for encoding and modulation.

[0303] Since the scheduling bandwidth is smaller than the virtual bandwidth, the signal length needs to be reduced or truncated to N before performing IFFT. RE0 or N RB0 , matching the scheduling bandwidth. And this process can introduce frequency domain spectrum shaping FDSS to further reduce PAPR, and the frequency domain shaping filtering operation can be achieved by weighting the frequency domain subcarriers. The above-mentioned truncation and FDSS operations are added together, namely the truncation filtering in this application, and truncation filtering can also be understood as selective mapping, that is, the transmitter only maps part of the complex samples or complex symbols after DFT to the frequency domain resources. The signal after truncated filtering is sent out through expansion, precoding (including second-level precoding, and optionally, first-level precoding), mapping, IFFT, adding CP and other operations.

[0304] like Figure 8 As shown, a diversity transmission process is provided. Figure 3 In the example, the modulation symbols are first grouped, then the symbols are spread, and then the spread signal is precoded. Figure 8 In the example, the modulation symbols are first grouped, and no extension is required for each group of symbols. Precoding can be performed directly. In the subsequent subcarrier mapping, the subcarriers between antenna port groups are orthogonal, which ensures that the intersection of the subcarrier sets of any two antenna port groups is an empty set. The rest of the details can be referred to each other and will not be repeated here. It should be noted that the following steps are only for the purpose of introducing Figure 8 Example with Figure 3 The difference between the examples, some of the same content is not introduced, you can refer to Figure 3 .

[0305] The following steps are involved:

[0306] Step 802: The transmitting end divides n modulation symbols into M groups of modulation symbols. The process of step 802 is the same as Figure 3 The process related to step 302 in is the same as that in Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e The examples of grouping in , repeated parts will not be repeated.

[0307] Optionally, step 803: the transmitting end performs discrete Fourier transform DFT on the mth group of modulation symbols to obtain the mth group of DFT symbols. The process of step 803 is the same as Figure 3 The process of step 303 is the same as that of step 303. Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e The DFT example in is repeated here.

[0308] Optionally, the transmitting end may determine the number of antenna port groups used for this diversity transmission. When n modulation symbols are generated by multiple coding blocks, the number of antenna port groups is equal to the number of coding blocks obtained by rate matching.

[0309] Optionally, the transmitting end determines which groups of valid symbols correspond to each antenna port group, that is, determines which antenna port group each group of valid symbols corresponds to. Different antenna port groups correspond to s groups of valid symbols, and the s corresponding to different antenna port groups are the same or different. If the DFT of step 803 is performed, the valid symbols are the symbols after DFT. If the DFT of step 803 is not performed, the valid symbols are the modulation symbols. For example, Figure 4a In the figure, D1 and D2 correspond to the antenna port group composed of "ant0 and ant1". Figure 4c In , D1 corresponds to the antenna port group consisting of "ant0 and ant1", and D2 corresponds to the antenna port group consisting of "ant2 and ant3". Figure 4e In , D1 and D2 correspond to the antenna port group composed of "ant0 and ant1", and D3 and D4 correspond to the antenna port group composed of "ant2 and ant3". Figure 4e In FIG, D1 and D2 correspond to the antenna port group consisting of "ant0 and ant1", and D3 corresponds to the antenna port group consisting of "ant2 and ant3".

[0310] Step 804: The transmitting end performs second-level precoding on the s groups of valid symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group.

[0311] The process of step 804 is the same as Figure 3 The process of step 305 in is similar, except that: Figure 3 In step 305, the extended symbols are pre-coded, while in step 804, the valid symbols (symbols after DFT or modulation symbols) are pre-coded. Figure 3 The second level precoding can refer to step 305. Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d and Figure 4e An example of the second level precoding in

[15] is described in detail below. Note that this example does not include extension and first level precoding.

[0312] exist Figure 4a In the figure, D1 and D2 are pre-coded at the second stage to obtain F1 and F2, where F1 is the symbol corresponding to ant0 and F2 is the symbol corresponding to ant1.

[0313] exist Figure 4b In the figure, D1 and D2 are pre-coded at the second level to obtain F1 and F2, where F1 is the symbol corresponding to ant0 and F2 is the symbol corresponding to ant1. D3 and D4 are pre-coded at the second level to obtain F3 and F4, where F3 is the symbol corresponding to ant0 and F4 is the symbol corresponding to ant1.

[0314] exist Figure 4c In the figure, D1 undergoes second-stage precoding to obtain F1 and F2, where F1 is the symbol corresponding to ant0 and F2 is the symbol corresponding to ant1. D2 undergoes second-stage precoding to obtain F3 and F4, where F3 is the symbol corresponding to ant0 and F4 is the symbol corresponding to ant1.

[0315] exist Figure 4d In the figure, D1 and D2 are pre-coded at the second level to obtain F1 and F2, where F1 is the symbol corresponding to ant0 and F2 is the symbol corresponding to ant1. D3 and D4 are pre-coded at the second level to obtain F3 and F4, where F3 is the symbol corresponding to ant0 and F4 is the symbol corresponding to ant1.

[0316] exist Figure 4e In the figure, D1 and D2 are pre-coded at the second level to obtain F1 and F2, where F1 is the symbol corresponding to ant0 and F2 is the symbol corresponding to ant1. D3 is pre-coded at the second level to obtain F3 and F4, where F3 is the symbol corresponding to ant0 and F4 is the symbol corresponding to ant1.

[0317] Step 805: Map the corresponding symbols of each antenna port to the subcarrier corresponding to the antenna port. Optionally, IFFT, CP addition, power adjustment, etc. may be performed before sending.

[0318] Here, "subcarrier corresponding to the antenna port" refers to the subcarrier used to transmit signals on this antenna port, and can also be understood as the subcarrier used to carry the symbol obtained in step 804 on this antenna port, rather than all subcarriers within the scheduling bandwidth.

[0319] Among them, the intersection of the subcarrier sets corresponding to any two antenna port groups is an empty set, which can also be understood as the subcarriers corresponding to any two antenna port groups do not overlap, are different, or are complementary. This is equivalent to Figure 3Characteristics 1 and 2 in the example: the positions of the s groups of modulation symbols corresponding to the g-th antenna port group in the s groups of extended symbols do not overlap or are different from or complementary to the positions of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols.

[0320] The subcarrier set corresponding to an antenna port group is the subcarrier for transmitting signals on this antenna port group, and can also be understood as the subcarrier for carrying the symbols obtained in step 804 on this antenna port group, rather than all subcarriers within the scheduling bandwidth.

[0321] In one example, for any antenna port group, the positions of the subcarriers corresponding to the antenna port group in the scheduling bandwidth are discontinuous.

[0322] For example, see Figure 6a As shown, assuming that there are two antenna port groups, D1 and D2 are the subcarriers corresponding to one antenna port group respectively, E1 and E2 are the subcarriers in the scheduling bandwidth, the subcarrier D1 corresponding to one antenna port group is the subcarrier at the odd position in the scheduling bandwidth, and the subcarrier D2 corresponding to the other antenna port group is the subcarrier at the even position in the scheduling bandwidth.

[0323] In one example, for any antenna port group, the subcarriers corresponding to the antenna port group are located continuously in the scheduling bandwidth.

[0324] For example, see Figure 6b As shown, assuming that there are two antenna port groups, D1 and D2 are the subcarriers corresponding to one antenna port group respectively, E1 and E2 are the subcarriers in the scheduling bandwidth, the subcarrier D1 corresponding to one antenna port group is the first half of the subcarriers in the scheduling bandwidth, and the subcarrier D2 corresponding to the other antenna port group is the second half of the subcarriers in the scheduling bandwidth.

[0325] In one example, for any antenna port group, subcarriers corresponding to the antenna port group are partially continuous and partially discontinuous in the scheduling bandwidth.

[0326] For example, see Figure 6c As shown in the figure, assuming there are three antenna port groups, D1, D2, and D3 are the subcarriers corresponding to each antenna port group. E1, E2, and E3 are the subcarriers in the scheduling bandwidth. D1 is the subcarrier at the 1st, 2nd, 7th, 8th, etc. positions in the scheduling bandwidth. D2 is the subcarrier at the 3rd, 4th, 9th, 10th, etc. positions in the scheduling bandwidth. D3 is the subcarrier at the 5th, 6th, 11th, 12th, etc. positions in the scheduling bandwidth.

[0327] Optionally, for an antenna port group, the intersection of the subcarrier sets corresponding to any two antenna ports is an empty set. It can also be understood that for an antenna port group, the subcarriers corresponding to any two antenna ports do not overlap, are different, or are complementary. In one example, in an antenna port group, for any antenna port: the position of the subcarrier corresponding to the antenna port in the subcarriers corresponding to the antenna port group is continuous; or, the position of the subcarrier corresponding to the antenna port in the subcarriers corresponding to the antenna port group is discontinuous; or, the subcarrier corresponding to the antenna port in the subcarriers corresponding to the antenna port group is continuous in some positions and discontinuous in some positions. It can still be done with Figure 6a 、 Figure 6b and Figure 6c Take 6a, Figure 6b and Figure 6c D1, D2, and D3 in the figure represent the subcarriers corresponding to an antenna port respectively, and E1, E2, and E3 represent the subcarrier sets corresponding to an antenna port group.

[0328] Optionally, for an antenna port group, the subcarriers corresponding to any two antenna ports are exactly the same. In an antenna port group, the subcarriers corresponding to any two antenna ports are in the same position among the subcarriers corresponding to the antenna port group.

[0329] Optionally, before executing step 804, the following may be further executed: the transmitting end performs first-level precoding on the v groups of valid symbols. Specific examples and processes can be found in the above introduction and will not be repeated here.

[0330] Optionally, before executing step 804, a "truncation" process may be performed:

[0331] The transmitter filters out (or discards) the first L1 and / or last L2 symbols in the mth group of valid signals (symbols after DFT or modulation symbols). Specific examples and processes can be found in the above description and will not be repeated here.

[0332] The above scheme does not take into account the demodulation reference signal (DMRS) signal. Before precoding, DMRS is mapped to the corresponding RE according to the rules corresponding to the DMRS port number, that is, the signal before precoding includes DMRS, data and PTRS.

[0333] The above describes the diversity communication processes performed by various transmitting ends. The diversity communication process performed by the receiving end is the reverse process of the transmitting end and will not be described in detail.

[0334] The preceding text describes the method of the embodiment of the present application. The following text describes the device of the embodiment of the present application. The method and device are based on the same technical concept. Since the principles of the method and device to solve the problem are similar, the implementation of the device and method can refer to each other, and the repeated parts will not be repeated.

[0335] In the embodiments of the present application, the functional modules of the device can be divided according to the above method examples. For example, each function can be divided into various functional modules, or two or more functions can be integrated into one module. These modules can be implemented in the form of hardware or software functional modules. It should be noted that the division of modules in the embodiments of the present application is schematic and is only a logical functional division. Other division methods may be used in specific implementations.

[0336] Based on the same technical concept as the above method, see Figure 9 , provides a schematic diagram of the structure of a diversity communication device 900, which can be a transmitter or a chip or functional unit used in the transmitter. The device 900 has any function of the transmitter in the above method, for example, the device 900 can perform the above Figure 2 、 Figure 3 、 Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d 、 Figure 8 The steps performed by the sending end in the method.

[0337] The apparatus 900 may include a processing module 910, and optionally, a receiving module 920a, a sending module 920b, and a storage module 930. The processing module 910 may be connected to the storage module 930, the receiving module 920a, and the sending module 920b, respectively. The storage module 930 may also be connected to the receiving module 920a and the sending module 920b.

[0338] The receiving module 920a can execute the receiving action performed by the transmitting end in the above method embodiment.

[0339] The sending module 920b can execute the sending action performed by the sending end in the above method embodiment.

[0340] The processing module 910 may execute other actions except the sending action and the receiving action among the actions executed by the sending end in the above method embodiment.

[0341] In one example, the processing module 910 is configured to divide n modulation symbols into M groups of modulation symbols, where M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; add one or more preset symbols to the modulation symbols of the mth group to obtain the mth group of extended symbols; m is an integer ranging from 1 to M; wherein the positions of the s groups of modulation symbols corresponding to the gth antenna port group in the s groups of extended symbols do not overlap with the positions of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols; perform second-level precoding on the s groups of extended symbols corresponding to the gth antenna port group to obtain symbols corresponding to each antenna port in the gth antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the gth precoding antenna port group is related to s and the number of antenna ports included in the gth antenna port group, where s is an integer greater than or equal to 1 and less than or equal to M. The transmitting module 920b is configured to transmit the symbols corresponding to each antenna port.

[0342] In an example, the processing module 910 is further configured to perform discrete Fourier transform (DFT) on the mth group of modulation symbols.

[0343] In one example, the processing module 910, when used to add one or more preset symbols to the modulation symbols of the mth group to obtain the mth group of extended symbols, is specifically used to: in the modulation symbols of the mth group, add x preset symbols to every y modulation symbols to obtain the mth group of extended symbols, where y is an integer greater than or equal to 1, and x is an integer greater than or equal to 1.

[0344] In one example, the receiving module 920a is configured to receive indication information, where the indication information is used to determine the precoding matrix.

[0345] In one example, the processing module 910 is also used to perform first-level precoding on v groups of expanded symbols, wherein the size of the precoding matrix used for the first-level precoding is v*v, and the elements in the precoding matrix of the first-level precoding are 0 and / or 1.

[0346] In an example, the processing module 910 is further configured to generate a modulation symbol using the following formula:

[0347] Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), It means i / M is rounded down, and j is the imaginary part.

[0348] In an example, the processing module 910 is further configured to filter out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

[0349] In an example, the receiving module 920a is configured to receive indication information, where the indication information is used to indicate a truncation factor, the value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor.

[0350] In one example, a processing module 910 is used to divide n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; the s groups of modulation symbols corresponding to the g-th antenna port group are subjected to second-level precoding to obtain symbols corresponding to each antenna port in the g-th antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the g-th precoding antenna port group is related to the s and the number of antenna ports included in the g-th antenna port group, s is an integer greater than or equal to 1 and less than or equal to M; the corresponding symbols of each antenna port are mapped to the subcarrier corresponding to the antenna port; the subcarriers corresponding to any two antenna port groups do not overlap; and a sending module 920b is used to send the symbols corresponding to each antenna port.

[0351] In one example, the processing module 910 is also used to perform first-level precoding on v groups of modulation symbols, wherein the size of the precoding matrix used for the first-level precoding is v*v, and the elements in the precoding matrix of the first-level precoding are 0 and / or 1.

[0352] In an example, the processing module 910 is further configured to filter out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

[0353] When the device is a baseband device, the receiving module 920a and the transmitting module 920b may be external communication interfaces of the baseband device. When the device is not a baseband device, the receiving module 920a and the transmitting module 920b may be antennas or antenna ports.

[0354] In an example, the storage module 930 may store computer-executable instructions of the method executed by the sending end, so that the processing module 910 , the receiving module 920 a , and the sending module 920 b execute the method executed by the sending end in the above example.

[0355] The aforementioned receiving module 920a and sending module 920b may also be integrated together and defined as a transceiver module.

[0356] For example, the storage module may include one or more memories, which may be devices in one or more devices or circuits used to store programs or data. The storage module may be a register, cache, or RAM, etc., and the storage module may be integrated with the processing module. The storage module may be a ROM or other type of static storage device that can store static information and instructions, and the storage module may be independent of the processing module.

[0357] The transceiver module may be an input or output interface, a pin or a circuit, etc.

[0358] The above describes the device applied to the transmitting end in the embodiment of the present application. The following describes the possible product forms of the device applied to the transmitting end. It should be understood that any device having the above Figure 9 Any product having the features of the device applied to the transmitting end falls within the scope of protection of this application. It should also be understood that the following description is only an example and should not limit the product form of the device applied to the transmitting end of the embodiment of this application to this.

[0359] As a possible product form, the device can be implemented by a general bus architecture.

[0360] like Figure 10 As shown, a schematic block diagram of a diversity communication device 1000 is provided. The device 1000 can be a transmitter or a chip used in a transmitter. It should be understood that the device has any function of the transmitter in the above method, for example, the device 1000 can perform the above Figure 2 、 Figure 3 、 Figure 4a 、 Figure 4b 、 Figure 4c 、 Figure 4d 、 Figure 8 The steps performed by the sending end in the method.

[0361] The apparatus 1000 may include a processor 1010 and, optionally, a transceiver 1020 and a memory 1030. The transceiver 1020 may be configured to receive programs or instructions and transmit them to the processor 1010, or may be configured to allow the apparatus 1000 to communicate with other communication devices, such as exchanging control signaling and / or service data. The transceiver 1020 may be a code and / or data reader / writer, or may be a signal transmission transceiver between the processor and the transceiver. The processor 1010 and the memory 1030 are electrically coupled.

[0362] For example, the memory 1030 is used to store computer programs; the processor 1010 can be used to call the computer program or instructions stored in the memory 1030 to execute the method executed by the sending end in the above example, or to execute the method executed by the sending end in the above example through the transceiver 1020.

[0363] Figure 9 The processing module 910 in the embodiment can be implemented by the processor 1010.

[0364] Figure 9 The receiving module 920a and the sending module 920b in the embodiment can be implemented by the transceiver 1020. Alternatively, the transceiver 1020 is divided into a receiver and a transmitter, the receiver performs the function of the receiving module, and the transmitter performs the function of the sending module.

[0365] Figure 9 The storage module 930 can be implemented by the memory 1030.

[0366] As a possible product form, the device may be implemented by a general-purpose processor (a general-purpose processor may also be referred to as a chip or a chip system).

[0367] In one possible implementation, a general-purpose processor implemented in a device applied to a transmitting end includes: a processing circuit (a processing circuit may also be referred to as a processor) and an input / output interface for internal communication with the processing circuit. Optionally, the processor also includes: a storage medium (a storage medium may also be referred to as a memory) for storing instructions executed by the processing circuit to perform the method performed by the transmitting end in the above example.

[0368] Figure 9 The processing module 910 in can be implemented by a processing circuit.

[0369] Figure 9 The receiving module 920a and the sending module 920b in the embodiment can be implemented by an input / output interface. Alternatively, the input / output interface is divided into an input interface and an output interface, the input interface performs the function of the receiving module, and the output interface performs the function of the sending module.

[0370] Figure 9 The storage module 930 can be implemented by a storage medium.

[0371] As a possible product form, the device of the embodiment of the present application can also be implemented using the following: one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits that can perform the various functions described throughout this application.

[0372] Figure 11 This is a schematic diagram of the structure of a transmitting end provided in an embodiment of the present application. The transmitting end may be, for example, a terminal.

[0373] The terminal includes at least one processor 1211 and at least one transceiver 1212. In one possible example, the terminal may also include at least one memory 1213, an output device 1214, an input device 1215, and one or more antennas 1216. The processor 1211, memory 1213, and transceiver 1212 are connected. The antenna 1216 is connected to the transceiver 1212, and the output device 1214 and input device 1215 are connected to the processor 1211.

[0374] The memory 1213 can exist independently and be connected to the processor 1211. In another example, the memory 1213 can also be integrated with the processor 1211, for example, integrated into a single chip. The memory 1213 can store program codes for executing the technical solutions of the embodiments of the present application, and the execution is controlled by the processor 1211. The various computer program codes executed can also be regarded as drivers for the processor 1211. For example, the processor 1211 is used to execute the computer program codes stored in the memory 1213, thereby implementing the technical solutions of the embodiments of the present application.

[0375] The transceiver 1212 can be used to support the reception or transmission of radio frequency signals between terminals, or between terminals and network devices, or between terminals and other devices. The transceiver 1212 can be connected to the antenna 1216. The transceiver 1212 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 1216 can receive radio frequency signals. The receiver Rx of the transceiver 1212 is used to receive the radio frequency signals from the antennas, convert the radio frequency signals into digital baseband signals or digital intermediate frequency signals, and provide the digital baseband signals or digital intermediate frequency signals to the processor 1211 so that the processor 1211 can further process the digital baseband signals or digital intermediate frequency signals, such as demodulation and decoding. In addition, the transmitter Tx in the transceiver 1212 is also used to receive modulated digital baseband signals or digital intermediate frequency signals from the processor 1211, convert the modulated digital baseband signals or digital intermediate frequency signals into radio frequency signals, and transmit the radio frequency signals through one or more antennas 1216. Specifically, the receiver Rx can selectively perform one or more stages of down-mixing and analog-to-digital conversion on the RF signal to obtain a digital baseband signal or a digital intermediate frequency signal. The order of the down-mixing and analog-to-digital conversion processes is adjustable. The transmitter Tx can selectively perform one or more stages of up-mixing and digital-to-analog conversion on the modulated digital baseband signal or digital intermediate frequency signal to obtain a RF signal. The order of the up-mixing and digital-to-analog conversion processes is adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as digital signals.

[0376] Processor 1211 can be used to implement various functions for the terminal, such as processing communication protocols and communication data, or controlling the entire terminal device, executing software programs, and processing software program data; or assisting in completing computing and processing tasks, such as graphics and image processing or audio processing, etc.; or processor 1211 is used to implement one or more of the above functions.

[0377] Output device 1214 communicates with processor 1211 and can display information in a variety of ways. For example, output device 1214 can be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. Input device 1215 communicates with processor 1211 and can receive user input in a variety of ways. For example, input device 1215 can be a mouse, keyboard, touch screen device, or sensor device.

[0378] The present application also provides a computer-readable storage medium storing a computer program that, when executed by a computer, enables the computer to perform the diversity communication method described above. In other words, the computer program includes instructions for implementing the diversity communication method described above.

[0379] An embodiment of the present application further provides a computer program product, including: computer program code, which, when executed on a computer, enables the computer to execute the diversity communication method provided above.

[0380] An embodiment of the present application further provides a communication system, which includes: a transmitting end and a receiving end for executing the above-mentioned diversity communication method.

[0381] In addition, the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), a baseband processor, the baseband processor and the CPU may be integrated together or separated, or may be a network processor (NP) or a combination of a CPU and an NP. The processor may further include a hardware chip or other general-purpose processor. The above-mentioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) and other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. or any combination thereof. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0382] The memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM). It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0383] The transceiver mentioned in the embodiments of the present application may include a separate transmitter and / or a separate receiver, or may be an integrated transmitter and receiver. The transceiver may operate under the instructions of a corresponding processor. Optionally, the transmitter may correspond to a transmitter in a physical device, and the receiver may correspond to a receiver in a physical device.

[0384] Those skilled in the art will appreciate that the various method steps and units described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the steps and components of each embodiment have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0385] Those skilled in the art will clearly understand that, for the sake of convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0386] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0387] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

[0388] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0389] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0390] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0391] The term "and / or" in this application describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated with each other are in an "or" relationship. The term "multiple" referred to in this application refers to two or more. In addition, it should be understood that in the description of this application, words such as "first" and "second" are only used to distinguish the description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0392] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by a computer program or instruction. These computer programs or instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0393] These computer programs or instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device that implements the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0394] These computer programs or instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide the instructions for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1The steps for the function specified in one or more boxes.

[0395] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0396] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

Claims

1. A method for transmitting a signal, characterized in that: The method comprises: The transmitting end divides n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; The transmitting end adds one or more preset symbols to the mth group of modulation symbols to obtain the mth group of extended symbols; the value of m is an integer from 1 to M; wherein the position of the sth group of modulation symbols corresponding to the gth antenna port group in the sth group of extended symbols does not overlap with the position of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols; The transmitting end performs first-level precoding on the v groups of expanded symbols, wherein the size of the precoding matrix used in the first-level precoding is v*v, and the elements in the precoding matrix of the first-level precoding are 0 and / or 1; The transmitting end performs second-level precoding on the s groups of expanded symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the g-th precoding antenna port group is related to s and the number of antenna ports included in the g-th antenna port group, where s is an integer greater than or equal to 1 and less than or equal to M; The transmitting end transmits a symbol corresponding to each antenna port.

2. The method according to claim 1, wherein In one antenna port group, positions of any group of modulation symbols in any group of extended symbols do not overlap with positions of another group of modulation symbols in another group of extended symbols; or, In one antenna port group, positions of any group of modulation symbols in any group of extended symbols are the same as positions of another group of modulation symbols in another group of extended symbols.

3. The method according to claim 1, wherein Before adding one or more preset symbols to the mth group of modulation symbols to obtain the mth group of extended symbols, the method further includes: The transmitting end performs discrete Fourier transform DFT on the mth group of modulation symbols.

4. The method according to claim 3, wherein The size of the DFT is the number of symbols in the mth group of modulation symbols.

5. The method according to any one of claims 1 to 4, characterized in that The M is greater than or equal to the number of antenna port groups, and the M is less than or equal to the sum of the numbers of antenna ports in the antenna port groups.

6. The method according to any one of claims 1 to 4, characterized in that The positions of the modulation symbols of the mth group in the symbols after the mth group is extended are not continuous; or, The positions of the modulation symbols of the mth group in the symbols after the mth group is extended are continuous; or, The modulation symbols of the mth group are continuous at some positions in the symbols after the mth group is expanded, and discontinuous at some positions.

7. The method according to claim 1, wherein The transmitting end adds one or more preset symbols to the mth group of modulated symbols to obtain the mth group of extended symbols, including: The transmitter adds x preset symbols to every y modulation symbols in the mth group of modulation symbols to obtain the mth group of extended symbols, where y is an integer greater than or equal to 1 and x is an integer greater than or equal to 1.

8. The method according to claim 7, wherein x is an integer multiple of y.

9. The method according to claim 7 or 8, wherein y is an integer multiple of the number of resource units RE included in the resource block group RBG.

10. The method according to claim 1, wherein Also includes: The transmitting end receives indication information, where the indication information is used to determine the precoding matrix.

11. The method according to claim 10, wherein The instruction information includes: a precoding matrix index, where the precoding matrix index is used to indicate a precoding matrix in a precoding matrix set, where the precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission; or precoding matrix index and indication of diversity transmission; or, A precoding matrix index and a precoding matrix set identifier, wherein the precoding matrices in the identified precoding matrix set are used for diversity transmission.

12. The method according to claim 1, wherein The precoding matrix of the first level precoding is a block diagonal matrix or a block anti-diagonal matrix.

13. The method according to claim 12, wherein: The blocks in the block diagonal matrix are unit matrices, and the number of rows and columns of the unit matrix is ​​the number of antenna ports in the antenna port group.

14. The method according to claim 1, wherein Before the transmitter divides the n modulation symbols into M groups of modulation symbols, it also includes: The transmitter generates modulation symbols using the following formula: Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), It means i / M is rounded down, and j is the imaginary part.

15. The method according to claim 14, wherein The transmitting end adds one or more preset symbols to the mth group of modulated symbols to obtain the mth group of extended symbols, further comprising: The transmitting end filters out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

16. The method according to claim 15, wherein Also includes: The transmitting end receives indication information, where the indication information is used to indicate a truncation factor, a value of L1 is determined according to the truncation factor, and a value of L2 is determined according to the truncation factor.

17. A method for transmitting a signal, characterized in that: The method comprises: The transmitting end divides n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; The transmitting end performs first-level precoding on the v groups of expanded symbols, wherein the size of the precoding matrix used in the first-level precoding is v*v, and the elements in the precoding matrix of the first-level precoding are 0 and / or 1; The transmitting end performs second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group to obtain symbols corresponding to each antenna port in the g-th antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the g-th precoding antenna port group is related to s and the number of antenna ports included in the g-th antenna port group, where s is an integer greater than or equal to 1 and less than or equal to M; The transmitting end maps the corresponding symbol of each antenna port to the subcarrier corresponding to the antenna port and sends it; wherein the subcarriers corresponding to any two antenna port groups do not overlap.

18. The method according to claim 17, wherein The subcarriers corresponding to any antenna port group are not located continuously in the scheduling bandwidth; or The subcarriers corresponding to any antenna port group are located continuously in the scheduling bandwidth; or, The subcarriers corresponding to any antenna port group are partially continuous and partially discontinuous in the scheduling bandwidth.

19. The method according to claim 17, wherein In an antenna port group, the subcarriers corresponding to any two antenna ports do not overlap; or, in an antenna port group, the subcarriers corresponding to any two antenna ports are the same.

20. The method according to any one of claims 17 to 19, wherein: The transmitting end performs second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group, further comprising: The transmitting end performs discrete Fourier transform DFT on the mth group of modulation symbols.

21. The method according to claim 20, wherein The size of the DFT is the number of symbols in the mth group of modulation symbols.

22. The method according to any one of claims 17 to 19, wherein: The M is greater than or equal to the number of antenna port groups, and the M is less than or equal to the sum of the numbers of antenna ports in the antenna port groups.

23. The method of claim 17, wherein: Also includes: The transmitting end receives indication information, where the indication information is used to determine the precoding matrix.

24. The method according to claim 23, wherein The instruction information includes: a precoding matrix index, where the precoding matrix index is used to indicate a precoding matrix in a precoding matrix set, where the precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission; or precoding matrix index and indication of diversity transmission; or, A precoding matrix index and a precoding matrix set identifier, wherein the precoding matrices in the identified precoding matrix set are used for diversity transmission.

25. The method of claim 17, wherein: The precoding matrix of the first level precoding is a block diagonal matrix or a block anti-diagonal matrix.

26. The method of claim 25, wherein: The blocks in the block diagonal matrix are unit matrices, and the number of rows and columns of the unit matrix is ​​the number of antenna ports in the antenna port group.

27. The method of claim 17, wherein: Before the transmitter divides the n modulation symbols into M groups of modulation symbols, it also includes: The transmitter generates modulation symbols using the following formula: Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), Indicates rounding i / M down, where j is the imaginary part.

28. The method of claim 27, wherein: The transmitting end performs second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group, further comprising: The transmitting end filters out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

29. The method of claim 28, wherein Also includes: The transmitting end receives indication information, where the indication information is used to indicate a truncation factor, a value of L1 is determined according to the truncation factor, and a value of L2 is determined according to the truncation factor.

30. A device for transmitting a signal, characterized in that: The device comprises: A processing module is configured to divide n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; add one or more preset symbols to the modulation symbols of the mth group to obtain the mth group of extended symbols; the value of m is an integer from 1 to M; wherein the position of the s group of modulation symbols corresponding to the gth antenna port group in the s group of extended symbols does not overlap with the position of at least one group of modulation symbols corresponding to any other antenna port group in the at least one group of extended symbols; and perform a first processing on the v groups of extended symbols. Level precoding, wherein the size of the precoding matrix used in the first level precoding is v*v, wherein the elements in the precoding matrix of the first level precoding are 0 and / or 1; performing second-level precoding on the s groups of expanded symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group; in the second level precoding, the dimension of the precoding matrix used in the g-th precoding antenna port group is related to s and the number of antenna ports included in the g-th antenna port group, and s is an integer greater than or equal to 1 and less than or equal to M; The sending module is used to send the corresponding symbol of each antenna port.

31. The device according to claim 30, wherein In one antenna port group, positions of any group of modulation symbols in any group of extended symbols do not overlap with positions of another group of modulation symbols in another group of extended symbols; or, In one antenna port group, positions of any group of modulation symbols in any group of extended symbols are the same as positions of another group of modulation symbols in another group of extended symbols.

32. The device according to claim 30, wherein The processing module is further configured to perform discrete Fourier transform (DFT) on the mth group of modulation symbols.

33. The device according to claim 32, wherein The size of the DFT is the number of symbols in the mth group of modulation symbols.

34. The device according to any one of claims 30 to 33, characterized in that The M is greater than or equal to the number of antenna port groups, and the M is less than or equal to the sum of the numbers of antenna ports in the antenna port groups.

35. The device according to any one of claims 30 to 33, characterized in that The positions of the modulation symbols of the mth group in the symbols after the mth group is extended are not continuous; or, The positions of the modulation symbols of the mth group in the symbols after the mth group is extended are continuous; or, The modulation symbols of the mth group are continuous at some positions in the symbols after the mth group is expanded, and discontinuous at some positions.

36. The device according to claim 30, wherein The processing module, when used to add one or more preset symbols to the modulation symbols of the mth group to obtain the mth group of extended symbols, is specifically used to: in the modulation symbols of the mth group, add x preset symbols for every y modulation symbols to obtain the mth group of extended symbols, where y is an integer greater than or equal to 1, and x is an integer greater than or equal to 1.

37. The device according to claim 36, wherein x is an integer multiple of y.

38. The device according to claim 36 or 37, characterized in that y is an integer multiple of the number of resource units RE included in the resource block group RBG.

39. The device according to claim 30, wherein Also includes: The receiving module is configured to receive indication information, where the indication information is used to determine the precoding matrix.

40. The device according to claim 39, wherein The instruction information includes: a precoding matrix index, where the precoding matrix index is used to indicate a precoding matrix in a precoding matrix set, where the precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission; or precoding matrix index and indication of diversity transmission; or, A precoding matrix index and a precoding matrix set identifier, wherein the precoding matrices in the identified precoding matrix set are used for diversity transmission.

41. The device according to claim 30, wherein The precoding matrix of the first level precoding is a block diagonal matrix or a block anti-diagonal matrix.

42. The device according to claim 41, wherein The blocks in the block diagonal matrix are unit matrices, and the number of rows and columns of the unit matrix is ​​the number of antenna ports in the antenna port group.

43. The device according to claim 30, wherein The processing module is further configured to generate a modulation symbol using the following formula: Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), It means i / M is rounded down, and j is the imaginary part.

44. The device according to claim 43, wherein The processing module is further configured to filter out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

45. The device according to claim 44, wherein Also includes: The receiving module is used to receive indication information, where the indication information is used to indicate a truncation factor, the value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor.

46. ​​A device for transmitting a signal, characterized in that: The device comprises: A processing module, configured to divide n modulation symbols into M groups of modulation symbols; M is an integer greater than or equal to 2, and n is an integer greater than or equal to 2; perform first-level precoding on the v groups of expanded symbols, wherein the size of the precoding matrix used in the first-level precoding is v*v, wherein the elements in the precoding matrix of the first-level precoding are 0 and / or 1; perform second-level precoding on the s groups of modulation symbols corresponding to the g-th antenna port group to obtain a symbol corresponding to each antenna port in the g-th antenna port group; in the second-level precoding, the dimension of the precoding matrix used by the g-th precoding antenna port group is related to the s and the number of antenna ports included in the g-th antenna port group, and s is an integer greater than or equal to 1 and less than or equal to M; map the corresponding symbol of each antenna port to the subcarrier corresponding to the antenna port; the subcarriers corresponding to any two antenna port groups do not overlap; The sending module is used to send the symbol corresponding to each antenna port.

47. The device according to claim 46, wherein The subcarriers corresponding to any antenna port group are not located continuously in the scheduling bandwidth; or The subcarriers corresponding to any antenna port group are located continuously in the scheduling bandwidth; or, The subcarriers corresponding to any antenna port group are partially continuous and partially discontinuous in the scheduling bandwidth.

48. The device according to claim 46, wherein In an antenna port group, the subcarriers corresponding to any two antenna ports do not overlap; or, in an antenna port group, the subcarriers corresponding to any two antenna ports are the same.

49. The device according to any one of claims 46 to 48, characterized in that The processing module is further configured to perform discrete Fourier transform (DFT) on the mth group of modulation symbols.

50. The device according to claim 49, wherein The size of the DFT is the number of symbols in the mth group of modulation symbols.

51. The device according to any one of claims 46 to 48, wherein The M is greater than or equal to the number of antenna port groups, and the M is less than or equal to the sum of the numbers of antenna ports in the antenna port groups.

52. The device of claim 46, wherein Also includes: The receiving module is configured to receive indication information, where the indication information is used to determine the precoding matrix.

53. The device according to claim 52, wherein The instruction information includes: a precoding matrix index, where the precoding matrix index is used to indicate a precoding matrix in a precoding matrix set, where the precoding matrix set includes a precoding matrix for diversity transmission and a precoding matrix for non-diversity transmission; or precoding matrix index and indication of diversity transmission; or, A precoding matrix index and a precoding matrix set identifier, wherein the precoding matrices in the identified precoding matrix set are used for diversity transmission.

54. The device of claim 46, wherein The precoding matrix of the first level precoding is a block diagonal matrix or a block anti-diagonal matrix.

55. The device according to claim 54, wherein The blocks in the block diagonal matrix are unit matrices, and the number of rows and columns of the unit matrix is ​​the number of antenna ports in the antenna port group.

56. The device of claim 46, wherein The processing module is further configured to generate a modulation symbol using the following formula: Where b represents a bit sequence, b(i) is the i-th bit in the bit sequence, i is an integer greater than or equal to 0, d(i) is the modulation symbol corresponding to b(i), Indicates rounding i / M down, where j is the imaginary part.

57. The device according to claim 56, wherein The processing module is further configured to filter out the first L1 and / or last L2 symbols in the mth group of modulation symbols, where L1 is an integer greater than or equal to 1, and L2 is an integer greater than or equal to 1.

58. The device according to claim 57, wherein Also includes: The receiving module is used to receive indication information, where the indication information is used to indicate a truncation factor, the value of L1 is determined according to the truncation factor, and the value of L2 is determined according to the truncation factor.

59. A communication device, characterized in that including processor and memory; The memory is used to store computer programs or instructions; The processor is configured to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, is configured to implement the method according to any one of claims 1 to 29.

60. A chip system, characterized in that: The chip system includes: a processing circuit; the processing circuit is coupled to a storage medium; The processing circuit is used to execute part or all of the computer programs or instructions in the storage medium, and when the part or all of the computer programs or instructions are executed, it is used to implement the method according to any one of claims 1 to 29.

61. A computer-readable storage medium, characterized in that Used to store a computer program, wherein the computer program includes instructions for implementing the method according to any one of claims 1 to 29.

62. A computer program product, characterized in that The computer program product comprises: a computer program code, and when the computer program code is run on a computer, the computer is caused to perform the method according to any one of claims 1 to 29.

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