Method and device for extending cyclic prefix of demodulation reference signal

Abstract

The present application relates to the technical field of communications. Provided are a method and device for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS), which are used for realizing lossless extension of a CP of a DMRS symbol. The method comprises: generating a demodulation reference signal (DMRS) symbol, wherein the DMRS symbol comprises an extended field, and the extended field comprises a supplementary cyclic prefix (SCP) or a cyclic suffix (CS); and sending a first signal, wherein the first signal comprises the DMRS symbol.

Description

Method and device for extending cyclic prefix of demodulation reference signal

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 22, 2023, with application number 202311574782.5 and application name “A method and device for extending the cyclic prefix of a demodulation reference signal”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of communication technology, and in particular to a method and device for extending a cyclic prefix of a demodulation reference signal. Background Art

[0003] Existing schemes for extending the cyclic prefix (CP) of a demodulation reference signal (DMRS) symbol treat the end of the symbol preceding the DMRS as the supplementary CP (SCP) of the DMRS symbol by making it approximately identical (not strictly identical, but with some error) to the signal at and before the CP interception point in the DMRS. In this case, the equivalent CP length of the DMRS symbol is equal to the sum of the CP length and the SCP length. This SCP approximation error can degrade channel estimation performance at high signal-to-noise ratios (SNRs).

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a method and apparatus for extending a demodulation reference signal cyclic prefix, which enables lossless extension of the CP of a DMRS symbol. Lossless extension of the CP can be understood as having no (approximate) error in the extended CP portion.

[0006] In a first aspect, an embodiment of the present application provides a method for extending a demodulation reference signal cyclic prefix, the method comprising: generating a demodulation reference signal DMRS symbol, the DMRS symbol including an extension field, the extension field including a supplementary cyclic prefix SCP or a cyclic suffix CS; sending a first signal, the first signal including the DMRS symbol.

[0007] In this possible implementation, an extension field is added to the DMRS symbol so that the CP of the DMRS symbol is losslessly extended.

[0008] In one possible implementation, when the extended field is an SCP, the SCP is the same as the first field, the first field is included in the DMRS symbol, and the cutoff point of the first field is a cyclic prefix (CP) interception point of the DMRS symbol. In this case, the equivalent CP of the DMRS symbol is the SCP and the original CP.

[0009] When the extended field is CS, the CS is the same as the second field. The second field is included in the DMRS symbol. The starting point of the second field is the next sampling point after the end position of the CP of the DMRS symbol. In this case, the equivalent CP of the DMRS symbol is the original CP and the second field.

[0010] In a possible implementation, the extension field is SCP.

[0011] In a possible implementation, the DMRS symbol is the first symbol of the first signal.

[0012] In one possible implementation, the tail field of the second symbol overlaps with the SCP in time, the length of the overlapping part is the length of the SCP, the second symbol is included in the second signal, the cutoff point of the tail field of the second symbol is the cutoff point of the second symbol, and the next sampling point of the cutoff point of the tail field of the second symbol is the starting point of the DMRS symbol CP.

[0013] In a possible implementation, the tail field of the second symbol is a redundant signal.

[0014] In this possible implementation, when the tail field of the second symbol is a redundant signal, the impact of adding the SCP in the DMRS symbol on the demodulation performance of the second symbol is reduced.

[0015] In a possible implementation, the first signal is located in a self-contained time slot, and the SCP of the DMRS symbol is located in a guard period GP.

[0016] In this possible implementation, when the first signal is located in a self-contained time slot, the extension field of the DMRS symbol is added to the GP without affecting other symbols.

[0017] In a possible implementation, the first signal is sent in a physical uplink shared channel, and the first signal is sent in advance according to the length of the SCP.

[0018] In this possible implementation, the first signal is sent in advance according to the length of the SCP, so that the first signal and the uplink signals sent by other UEs are aligned in time when they arrive at the network device, and then the network device can process the uplink signals sent by all UEs in the same cell at one time.

[0019] In one possible implementation, the DMRS symbol is not the last symbol of the first signal, the header field of the third symbol is replaced by the tail field of the DMRS symbol, the starting point of the header field of the third symbol is the starting point of the third symbol, the end point of the tail field of the DMRS symbol is the end point of the DMRS symbol, the third symbol is the next symbol after the DMRS symbol in the first signal, and the length of the replaced part of the third symbol is the length of the SCP.

[0020] In a possible implementation, the tail field of the fourth symbol is replaced with SCP, the fourth symbol is the symbol before the DMRS symbol, and the cutoff point of the tail field of the fourth symbol is the cutoff point of the fourth symbol.

[0021] In a possible implementation manner, the first signal is transmitted through a physical downlink shared channel.

[0022] In a possible implementation, the tail field of the fourth symbol is a redundant signal.

[0023] In this possible implementation, when the tail field of the fourth symbol is a redundant signal, the impact of adding the SCP in the DMRS symbol on the demodulation performance of the fourth symbol is reduced.

[0024] In a possible implementation, the extension field is CS.

[0025] In one possible implementation, the DMRS symbol is not the last symbol in the first signal, the header field of the third symbol is replaced with CS, the starting point of the header field of the third symbol is the starting point of the third symbol, and the third symbol is the symbol after the DMRS symbol in the first signal.

[0026] In a possible implementation, the DMRS symbol is the last symbol in the first signal, the first signal is located in a self-contained time slot, and the CS of the DMRS symbol is located in a guard period GP.

[0027] In this possible implementation, when the first signal is located in a self-contained time slot, the extension field of the DMRS symbol is added to the GP without affecting other symbols.

[0028] In one possible implementation, generating a demodulation reference signal DMRS symbol includes determining, based on first information, whether to generate an extended field as SCP or CS, where the first information may include one or more of the following information: a positional relationship between the DMRS symbol and the protection period GP; the type of the second symbol, the type of the third symbol, and the type of the fourth symbol; a modulation coding scheme MCS or error vector magnitude EVM of the second symbol, the MCS or EVM of the third symbol, or the MCS or EVM of the fourth symbol; and a multiplexing method of multi-user DMRS symbols.

[0029] In this possible implementation, it is necessary to generate DMRS symbols according to the first information, which reduces adverse effects on other symbols (which may or may not belong to the first signal).

[0030] In one possible implementation, generating a demodulation reference signal DMRS symbol includes: determining the length of an extended field for generating the DMRS symbol based on second information, the second information including one or more of the following information: a maximum channel delay extension experienced by the first signal; a length of the cyclic prefix CP; an operating signal-to-noise ratio SNR of the first signal; an MCS or EVM of the second symbol, an MCS or EVM of the third symbol, or an MCS or EVM of the fourth symbol.

[0031] In this possible implementation, the length of the extended field needs to be determined based on the second information, reducing the adverse impact on other symbols (which may or may not belong to the first signal). Determining the length of the extended field requires considering the maximum channel delay spread experienced by the first signal, which is conducive to achieving lossless channel estimation performance for DMRS symbols. Determining the length of the extended field requires considering the operating signal-to-noise ratio (SNR) of the first signal, which can achieve a good compromise between channel estimation accuracy and overhead (such as introduced by redundant signals).

[0032] In a possible implementation, the extension field of the DMRS symbol is located within a protection period GP, and the second information further includes the length of the GP.

[0033] In this possible implementation, the second information further includes the length of the GP to avoid a conflict (or collision) between an uplink signal in the SCP and a downlink signal before the GP, or to avoid a conflict (or collision) between a downlink signal in the SCP or CS and an uplink signal after the GP.

[0034] In a possible implementation, before generating a demodulation reference signal DMRS symbol, the method further includes: receiving control information, the control information indicating: the length of the SCP; or the length of the CS; or the extension field being the SCP or the CS and the length of the extension field.

[0035] In one possible implementation, the control information includes first control information and second control information. The first control information is carried through downlink control information DCI, and the first control information indicates whether the DMRS symbol includes an extension field; if the first control information indicates that the DMRS symbol includes an extension field, the second control information is carried through media access control element MAC-CE signaling or radio resource control RRC signaling, and the second control information indicates the length of the extension field.

[0036] In one possible implementation, the control information includes first control information and second control information. The first control information is carried through DCI, and the first control information indicates whether the DMRS symbol includes an extended field and, if included, the length of the extended field; the second control information is carried through MAC-CE signaling or RRC signaling, and the second control information includes a set of candidate lengths for multiple extended fields, and the length of the extended field indicated by the first control information is included in the candidate length set.

[0037] In a possible implementation manner, when the first control information indicates that the DMRS symbol includes an extension field, the first control information further indicates that the extension field is SCP or CS.

[0038] In a second aspect, an embodiment of the present application provides a demodulation reference signal cyclic prefix extension method, the method comprising: a user equipment generates a demodulation reference signal DMRS symbol, the DMRS symbol includes an extension field, the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; the user equipment sends a first signal, the first signal includes a DMRS symbol

[0039] In a possible implementation, before the user equipment generates a demodulation reference signal (DMRS) symbol, the method further includes:

[0040] The user equipment receives control information, where the control information indicates: the length of the SCP; or the length of the CS; or the extension field is the SCP or the CS and the length of the extension field.

[0041] In a third aspect, an embodiment of the present application provides a method for extending a demodulation reference signal cyclic prefix, the method comprising: a network device transmitting control information, the control information indicating: the length of a supplementary cyclic prefix (SCP); or the length of a cyclic suffix (CS); or the length of an extension field (SCP or CS) and the length of the extension field. The network device receives a first signal, the first signal comprising a demodulation reference signal (DMRS) symbol, the DMRS symbol comprising an extension field, and the extension field comprising the SCP or CS.

[0042] In a fourth aspect, an embodiment of the present application provides a method for extending a demodulation reference signal cyclic prefix, the method comprising: a network device generates a demodulation reference signal DMRS symbol, the DMRS symbol includes an extension field, the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; the network device sends a first signal, the first signal includes a DMRS symbol.

[0043] In a possible implementation, before the network device sends the first signal, the method further includes: the network device sends a control message, where the control information indicates: the length of the SCP; or the length of the CS; or the extension field is the SCP or CS and the length of the extension field.

[0044] In a fifth aspect, an embodiment of the present application provides a method for extending a demodulation reference signal cyclic prefix, the method comprising: a user equipment receives a first signal, the first signal comprises a DMRS symbol, the DMRS symbol comprises an extension field, and the extension field comprises a supplementary cyclic prefix SCP or a cyclic suffix CS.

[0045] In a possible implementation, the method further includes: the user equipment receiving a control message, where the control information indicates: the length of the SCP; or the length of the CS; or the extension field is the SCP or the CS and the length of the extension field.

[0046] In a sixth aspect, embodiments of the present application provide a user device comprising: a processor and a memory. The processor is coupled to the memory; the memory is configured to store computer instructions, which are loaded and executed by the processor to cause the user device to implement any one of the methods provided in the first, second, or fifth aspects.

[0047] In a seventh aspect, an embodiment of the present application provides a network device comprising: a processor and a memory. The processor is coupled to the memory; the memory is configured to store computer instructions, which are loaded and executed by the processor to cause the network device to implement any one of the methods provided in the first, third, or fourth aspects.

[0048] In an eighth aspect, an embodiment of the present application provides a chip comprising: a processor and an interface circuit; the interface circuit is used to receive code instructions and transmit them to the processor; and the processor is used to run the code instructions to execute any one of the methods provided in the first aspect, the second aspect, or the fifth aspect.

[0049] In the ninth aspect, an embodiment of the present application provides a chip, which includes: a processor and an interface circuit; the interface circuit is used to receive code instructions and transmit them to the processor; the processor is used to run the code instructions to execute any one of the methods provided in the first aspect, the third aspect or the fourth aspect.

[0050] In the tenth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores at least one computer program instruction, and the computer program instruction is loaded and executed by a processor to implement any one of the methods provided in the first, second or fifth aspects above.

[0051] In the eleventh aspect, an embodiment of the present application provides a computer-readable storage medium, which stores at least one computer program instruction, and the computer program instruction is loaded and executed by a processor to implement any one of the methods provided in the first, third or fourth aspects above.

[0052] In the twelfth aspect, an embodiment of the present application provides a computer program product, including computer execution instructions, which, when the computer execution instructions are run on a computer, enable the computer to execute any one of the methods provided in the first aspect, the second aspect or the fifth aspect.

[0053] In the thirteenth aspect, an embodiment of the present application provides a computer program product, including computer execution instructions, which, when the computer execution instructions are run on a computer, enable the computer to execute any one of the methods provided in the first aspect, the third aspect or the fourth aspect.

[0054] The technical effects brought about by any implementation method in the sixth to thirteenth aspects can be referred to the technical effects brought about by the corresponding implementation methods in the first to fifth aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 is a schematic diagram of an OFDM / DFT-s-OFDM network architecture;

[0056] FIG2 is a schematic diagram of an OFDM CP insertion scenario;

[0057] FIG3 is a schematic diagram of a scenario in which the RX FFT window position is moved forward;

[0058] FIG4 is a schematic diagram of a time-domain linear convolution single-carrier modulation scenario;

[0059] FIG5 is a schematic diagram of the network architecture of a SC-FDE system block diagram;

[0060] FIG6 is a schematic diagram of a scenario of NR PDSCH / PUSCH DMRS design;

[0061] FIG7 is a schematic diagram of a scenario of an S time slot;

[0062] FIG8 is a schematic diagram of a scenario with a single-cycle 8:2 time slot ratio;

[0063] FIG9 is a schematic diagram of a downlink to uplink switching scenario;

[0064] FIG10 is a schematic diagram of a scenario in which TA is used to implement uplink transmission time calibration;

[0065] FIG11a is a schematic diagram of a scenario in which the CP is extended forward;

[0066] FIG11 b is a schematic diagram of a scenario in which the CP is extended backward;

[0067] FIG12 is a schematic diagram of a before DFT replication scenario;

[0068] FIG13 is a schematic diagram of a scenario of a wireless communication system provided in an embodiment of the present application;

[0069] FIG14 is a schematic diagram of a flow chart of a method for extending a cyclic prefix of a demodulation reference signal provided in an embodiment of the present application;

[0070] FIG15 is a schematic diagram of a scenario of a method for extending a cyclic prefix of a demodulation reference signal provided by an embodiment of the present application;

[0071] FIG16 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0072] FIG17 is a schematic diagram of another scenario of a method for extending a cyclic prefix of a demodulation reference signal provided by an embodiment of the present application;

[0073] FIG18 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0074] FIG19 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0075] FIG20 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0076] FIG21 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided by an embodiment of the present application;

[0077] FIG22 is a schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0078] FIG23 is a schematic diagram of the structure of a user equipment provided in an embodiment of the present application;

[0079] FIG24 is a schematic diagram of the structure of another user equipment provided in an embodiment of the present application;

[0080] FIG25 is a schematic diagram of the structure of a network device provided in an embodiment of the present application;

[0081] FIG26 is a schematic diagram of the structure of another network device provided in an embodiment of the present application;

[0082] FIG27 is a schematic diagram of the structure of another user equipment provided in an embodiment of the present application;

[0083] FIG28 is a schematic diagram of the structure of another network device provided in an embodiment of the present application;

[0084] Figure 29 is a structural diagram of a communication system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0085] In the description of this application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B; "and / or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0086] In the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or plural.

[0087] In addition, to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or execution order, and the words "first" and "second" do not necessarily mean different.

[0088] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner to facilitate understanding.

[0089] It will be understood that the “embodiment” mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, the various embodiments throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It will be understood that in the various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0090] It is understood that some optional features in the embodiments of the present application may, in certain scenarios, be implemented independently of other features, such as the solutions on which they are currently based, to solve corresponding technical problems and achieve corresponding effects. Alternatively, they may be combined with other features as needed in certain scenarios. Accordingly, the devices provided in the embodiments of the present application may also implement these features or functions accordingly, and detailed description thereof will not be given here.

[0091] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referenced to each other. In this application, unless otherwise specified and there is no logical conflict between the various embodiments, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. Different embodiments can be combined to form new embodiments based on their inherent logical relationships. The following implementation methods of this application do not constitute a limitation on the scope of protection of this application.

[0092] To facilitate understanding of the technical solutions of the embodiments of the present application, a brief introduction to the relevant technologies of the present application is first given as follows:

[0093] 1. Channels, multipath and delay spread.

[0094] In a radio system, the medium that carries the signal from the transmitter to the receiver is called the channel.

[0095] Multipath is a propagation phenomenon that causes a radio signal to take two or more paths to the receiver. Multipath can be caused by atmospheric ducting, ionospheric reflection, refraction, and reflection from water and land objects.

[0096] Because these multiple copies of the transmitted signal travel different distances (i.e., each path has a different propagation distance), the receiver receives these copies at different times. The time difference between the arrival of the first and last path components of the signal is called the maximum delay spread (MDS).

[0097] If a signal is received at a given time and then a copy of that signal is received a fraction of a second later, the information becomes "blurred" due to the temporal overlap of the signals. As MDS increases, the quality of the received signal degrades, and the transmitted signal cannot be correctly demodulated, ultimately leading to a loss of communication.

[0098] On the other hand, in actual links, when the baseband shaped pulses (or filters) and RF filters are non-Nyquist pulses, these shaped pulses and filters will also cause delay spread in the received signal.

[0099] 2. Orthogonal frequency division multiplexing.

[0100] Figure 1 is a schematic diagram of the OFDM system framework. Through serial to parallel conversion (s-to-p), M consecutive data symbols can be converted into M-dimensional data blocks S k =[S k [0],S k [1],…,S k [M-1]] T , k is the OFDM symbol number. Through subcarrier mapping, S k The M data carried modulates M subcarriers among the N subcarriers, and the remaining NM subcarriers can be understood as being modulated by 0. k A set of N complex time domain sampling points x is obtained by performing an inverse fast Fourier transform (IFFT) of N points. k =[x k [0],x k [1],…,x k [N-1]] T .

[0101] As shown in Figure 2, the next important step in generating OFDM signals is to insert a guard field at the beginning of each OFDM symbol to eliminate inter-symbol interference (ISI) caused by multipath propagation. The guard field is obtained by adding a cyclic prefix (CP) to the beginning of the symbol. k The last G samples (i.e. x k [NG],…,x k [N-1]) and append them to X k At the beginning of an OFDM symbol, there is valid data X k And cyclic prefix (i.e. redundant data), the time domain OFDM signal is obtained:

[0102] Among them, [x k [NG],…,x k [N-1]] T Indicates CP.

[0103] 3. CP interception point.

[0104] The CP intercept point corresponds to the sampling index NG-1. That is, the next sampling value of the CP intercept point is equal to the first value of CP.

[0105] The signal is transmitted through a multipath channel. In order to completely eliminate ISI, the selected CP length must be greater than or equal to the maximum delay spread T d . Define T sis the sampling interval, that is, the two adjacent sampling points x k [n] and x k The time interval between [n+1], the selected CP length must be greater than T d It can be understood as in Represents the ceiling operator.

[0106] At the receiving end, the OFDM signal is demodulated by inverse processing to obtain time and frequency synchronization and the CP length is not less than T d , after removing the CP operation (i.e. removing the first G samples in the received signal), a data block containing N samples with no ISI is obtained, which is also equal to the OFDM symbol X k The time-domain circular convolution is converted to a frequency-domain dot product through the Fast Fourier Transform (FFT) and the channel impulse response. This allows for low-complexity channel equalization using frequency-domain single-tap equalization.

[0107] As shown in Figure 3, timing synchronization errors may exist in actual links. To minimize the negative impact of ISI in the presence of timing errors, the receiver often shifts the FFT window position forward. The shift is generally 10%-20% of the CP length. That is, if there is no timing error, the CP length will be equivalently reduced by 10%-20%. If T d If the receive (RX) FFT window advance exceeds the CP length, the symbols will also be affected by ISI and ICI. For example, the corresponding signal of the last path may not fall completely within the RX FFT window.

[0108] In this application, insufficient (or insufficient) CP may be understood as CP being lower than the channel MDS, or CP being lower than the sum of the channel MDS and the timing synchronization error.

[0109] It can be understood that when the CP length is sufficient, ISI can be avoided and the channel linear convolution can be converted to a circular convolution, enabling low-complexity frequency-domain channel equalization.

[0110] The CP part carries redundant data, and the corresponding spectrum efficiency loss is T CP / T symb , where T CP is the duration of CP, and T symb is the duration of an OFDM symbol. symb =T CP +T u , T u =NT s =1 / Δf, Δf is the subcarrier spacing. uThe physical meaning is valid data X k duration.

[0111] 4. Orthogonal frequency division multiplexing with discrete Fourier transform spread spectrum.

[0112] Discrete Fourier Transform spreading OFDM (DFT-s-OFDM) defines the data blocks s transmitted in the time domain. k , there is an additional DFT (Discrete Fourier Transform) process before the OFDM process, that is, for each data block s containing M data k Perform an M-point DFT operation. This operation gives the DFT-s-OFDM signal the characteristics of a single carrier, with a peak-to-average power ratio (PAPR) much lower than that of multi-carrier signals such as OFDM. Therefore, at the same power amplifier, DFT-s-OFDM can provide greater output power and higher power amplifier efficiency, thereby achieving the goal of improving coverage and reducing energy consumption. The coverage and power consumption advantages of DFT-s-OFDM are particularly evident on the terminal device side. Therefore, in the current versions of the Long Term Evolution (LTE) plan and the New Radio (NR), DFT-s-OFDM is used for uplink transmission.

[0113] Data series k It may include modulation symbols and / or redundant signal sampling points. The modulation symbol may be a modulation symbol obtained by modulating a (coded) bit stream. The modulation scheme may include pulse amplitude modulation (PAM), phase shift keying (PSK), quadrature amplitude modulation (QAM), offset quadrature amplitude modulation (OQAM), amplitude phase shift keying (APSK), etc. The sampling points of the redundant signal may include phase tracking reference signal (PTRS) sampling points, unique words, and zeros, etc.

[0114] 5. Time domain linear convolution single carrier modulation.

[0115] As shown in Figure 4, a single carrier (SC) is linearly convolved in the time domain and then filtered using a shaping filter to generate a signal x. Shaping filtering involves two processes: upsampling and filtering (i.e., linear convolution of the upsampled signal with the shaped pulse).

[0116] The data sequence may include modulation symbols and / or redundant signal sampling points. The modulation symbol may be a modulation symbol obtained by modulating the (encoded) bit stream. The modulation method may include pulse amplitude modulation (PAM), phase shift keying (PSK), quadrature amplitude modulation (QAM), offset quadrature amplitude modulation (OQAM), amplitude phase shift keying (APSK), etc. The sampling points of the redundant signal may include phase tracking reference signal (PTRS) sampling points, unique words, and zeros, etc.

[0117] In DFT-s-OFDM, the upsampling factor is N / M, and the shaped pulse has a period, which is N. Therefore, the DFT-s-OFDM signal X k Can be understood as data block s k Circular convolution with shaped pulses.

[0118] 6. Single carrier-frequency domain equalization.

[0119] As shown in Figure 5, single carrier frequency domain equalization SC-FDE is based on time domain linear convolution SC modulation. First, the data sequence is divided into a series of data blocks of length M by the partition module. k Each data block adds Q length CP, that is, copies s k The last Q data to s k in front of (at this time the CP interception point corresponds to data index MQ-1).

[0120] Due to CP, the linear convolution of the multipath channel is converted into a circular convolution, and the receiver can use low-complexity single-tap frequency-domain channel equalization.

[0121] In fact, adding a CP containing Q symbols before the shaping filter can also be equivalent to adding a CP containing Q symbols after the pulse shaping filter. or CP of sample values, where Pup Represents the upsampling factor. represents the floor operator, and represents the ceiling operator. That is, or It can be understood as equal to G.

[0122] 7. CP length in NR protocol.

[0123] Currently, the CP length is described in the 3GPP related protocols as in Indicates the index number of the symbol in the subframe, where Indicates the number of OFDM symbols contained in a slot, and Indicates the number of slots in a subframe (1ms in duration) when the parameter set (Numerology) is μ. In addition, the OFDM symbol period is described as The formula is:

[0124] Here, κ = 64. As can be seen, NR supports two CP lengths: normal CP (CP) and extended CP (ECP). The CP overhead is approximately 144 / (2048 + 144) = 6.6%, while the ECP overhead is approximately 512 / (512 + 2048) = 20%. Therefore, the ECP overhead is much higher than the CP. Furthermore, NR currently stipulates that CP or ECP can only be used when μ = 2, that is, when the subcarrier spacing is 60 kHz. CP is used for other μ values.

[0125] At the sampling interval T s If certain, the application may use the number of sampling points included in the time length to describe the time length.

[0126] 8. MCS (modulation and coding scheme) and EVM (Error Vector Magnitude).

[0127] An MCS index corresponds to a modulation mode and code rate. The smaller the MCS, the lower the modulation order, the lower the code rate, and the lower the spectrum efficiency, but the stronger the ability to resist interference (such as ISI and ICI).

[0128] The error vector magnitude (EVM) of a QAM / PSK modulated signal is often used to measure signal quality. EVM is defined as the ratio of the error vector magnitude to the reference signal magnitude, sometimes expressed as a percentage. The EVM calculation formula is as follows:

[0129] Wherein, P is the number of QAM / PSK symbols, r(p) is the reference signal, z(p) is the observed signal, and z(p)-r(p) is the error.

[0130] 9. Base station signaling.

[0131] In the present application, the signaling may be radio resource control (RRC) signaling, system information (SI), remaining minimum system information (RMSI), NR system information block 0 (new radio system information block type 0, NR SIB0), NR system information block 1 (new radio system information block type 1, NR SIB1), medium access control-control element (MAC CE) signaling, downlink control information (DCI), physical broadcast channel (PBCH), or physical downlink control channel (PDCCH) instructions, etc.

[0132] Radio Resource Control (RRC): This system manages, controls, and schedules radio resources through specific strategies and methods. It maximizes the use of limited wireless network resources while meeting quality of service requirements, ensuring coverage within the planned area and maximizing service capacity and resource utilization.

[0133] Media Access Control (MAC): Located between the RRC layer and the physical layer, it is mainly responsible for controlling the transmission and other functions of the physical layer.

[0134] 10. Demodulation reference signal (DMRS)

[0135] As shown in Figure 6, the demodulation reference signal (DMRS) symbol for the physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) is used for channel estimation during PDSCH / PUSCH demodulation, using DFT-s-OFDM or OFDM modulation. The DMRS symbol has the same subcarrier spacing Δf as the data symbol. In order to track channels that change over time and support more accurate demodulation, the NR protocol introduces more DMRS symbols or groups or increases the reference signal density in the time domain, that is, sending multiple DMRS symbols. The receiver first estimates the channel at the reference signal, and then obtains the channel at the data symbol by interpolation in the time domain, and then demodulates the data.

[0136] 11. Self-contained time slot.

[0137] Typically, in time division duplexing (TDD) mode, uplink and downlink transmissions are separated by time slots: uplink slots (U slots) are used entirely for uplink transmissions, while downlink slots (D slots) are used entirely for downlink transmissions. Self-contained slots (hereinafter referred to as S slots) support both uplink and downlink transmissions within a single time slot. Through time division multiplexing, uplink (UL) and downlink (DL) transmissions are located on different OFDM symbols within the same time slot.

[0138] As shown in Figure 7, during the S-slot, both the base station and user equipment (UE) need to switch between uplink and downlink transmission. A guard period (GP) ensures that uplink and downlink transmissions can continue to function normally after the switch. No signals are transmitted or received during the GP. The GP is typically an integer multiple of the OFDM symbol duration. In Figure 8, the S-slot consists of six downlink symbols (DL symbols), four guard symbols (GP symbols), and four uplink symbols (UL symbols).

[0139] As shown in Figure 9, GP only exists in downlink-to-uplink switching. From the base station's perspective, the round trip delay (RTD) from DL to UL is unavoidable, and no waiting is required from UL to DL. The situation is exactly the opposite from the terminal's perspective: the round trip delay (RTD) from UL to DL is unavoidable, and no waiting is required from DL to UL.

[0140] 12. Timing advance (TA).

[0141] As shown in Figure 10, due to the varying distances between different UEs and the base station within a cell, when timing advance (TA) is not used, the propagation delays experienced by uplink signals sent by UEs at different locations in the cell before reaching the base station vary, resulting in time misalignment of uplink signals from each UE upon arrival at the base station. With TA, however, signals sent by UEs at different locations within the cell are time-aligned upon arrival at the base station, allowing the base station to process all UEs within the cell at the same time. This is the reason for the introduction of TA.

[0142] Under the LTE or NR protocol, the timing advance TA = 2*t prop +t offset , where t prop represents the transmission delay, and t offset This is related to the TDD base station's transmit / receive transition delay. The TA is communicated to the UE via a timing advance command (TA command, TAC).

[0143] In the LTE / NR protocol, in order to combat channel delay spread and timing synchronization errors, the CP method is adopted, and two CP lengths, normal CP (CP) and extended CP (ECP), are supported. In order to perform flexible multi-user multiplexing and achieve symbol length alignment for different users, both CP and ECP are configured at the cell level, that is, all users in this cell are configured with the same CP length. If the MDS in the cell is less than the CP, all users in the cell are configured with CP; if the MDS in the cell is greater than the CP, all users in the cell are configured with ECP. This cell-level CP configuration method causes a large loss of spectrum efficiency for users with small DS and users whose MDS partially exceeds the CP, and the existing LTE / NR protocol cannot flexibly configure the CP length according to user needs.

[0144] In one DMRS symbol CP extension scheme, as shown in Figures 11(a) and 11(b), the end signal of the symbol preceding the demodulation reference signal (DMRS) (e.g., the R22 portion of the symbol preceding the DMRS symbol in Figure 11(a)) is made identical to the signal within the DMRS at and before the CP cutoff point (e.g., the R22 portion of the DMRS symbol in Figure 11(a)). In this case, the DMRS has an equivalent CP length equal to the original CP length plus the length of R22. R22 serves as the supplementary CP (SCP). It should be understood that the CP can also be extended backward, with the supplementary CP being identical to the target field in the symbol following the DMRS, with the starting point of the target field being the starting point of the symbol following the DMRS, as shown in R21 in Figure 11(b). In this case, the DMRS has an equivalent CP length equal to the CP length plus the length of R21, with R21 serving as the CS. Backward CP extension requires a backward shift in the RX FFT window position by the length of R21.

[0145] This solution applies to situations where the symbols preceding or following the DMRS are modulated using DFT-s-OFDM or single-carrier modulation. DFT-s-OFDM modulation and CP forward extension are assumed. As shown in Figure 12, assume that the DMRS symbol corresponds to DFT input data block 2. Component 2 in data block 2 undergoes DFT-s-OFDM modulation to produce R22 in the DMRS symbol. As shown in Figure 12, component 2 is copied to the end of component 1 to form data block 1. Data block 1 undergoes DFT-s-OFDM modulation to produce the symbol preceding the DMRS.

[0146] In existing cyclic prefix extension schemes for demodulation reference signals, the R22 (R21) portion of a DMRS symbol is approximately the same as the R22 (R21) portion of the preceding (following) symbol. At high signal-to-noise ratios (SNRs), this approximation error can degrade channel estimation performance.

[0147] The present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), satellite communication system, long term evolution (LTE) system, etc. The present application can also be applied to future communication systems, such as sixth generation mobile communication system. The present application can also be applied to device to device (D2D) communication, vehicle-to-everything (V2X) communication, machine to machine (M2M) communication, machine type communication (MTC), and Internet of Things (IoT) communication system or other communication systems.

[0148] Figure 13 is a schematic diagram of a wireless communication system applicable to the present application. The wireless communication system may include at least one network device, such as network device 111, network device 112, and network device 113 shown in Figure 13. The wireless communication system may also include at least one terminal device, such as terminal device 121, terminal device 122, terminal device 123, terminal device 124, terminal device 125, terminal device 126, and terminal device 127 shown in Figure 13. Network devices can communicate with terminal devices, such as multi-site transmission shown in Figure 13, where network device 112 can communicate with terminal devices 121, 122, and 123; or enhanced mobile broadband (eMBB) transmission shown in Figure 13, where network devices 112 and 113 can communicate with terminal device 124. Network devices can also communicate with each other, such as backhaul shown in Figure 13, where network device 111 can communicate with network devices 112 and 113. Terminal devices may also communicate with each other, such as the D2D transmission shown in FIG. 13 , where terminal device 122 may communicate with terminal device 125 .

[0149] It should be understood that Figure 13 above is an exemplary illustration and the present application is not limited thereto. The present application can be applied to any communication scenario in which a transmitting device and a receiving device communicate. It should also be understood that the communication devices involved in the present application (such as a transmitting device and a receiving device) can be network devices or terminal devices. For example, the transmitting device mentioned in the present application can be a terminal device, and the receiving device can be a network device. For another example, the transmitting device mentioned in the present application can be a network device, and the receiving device can be a terminal device. For another example, both the transmitting device and the receiving device mentioned in the present application can be terminal devices. For another example, both the transmitting device and the receiving device mentioned in the present application can be network devices.

[0150] Terminal equipment in a communication system can be referred to as user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. Terminal equipment can be a device that provides voice / data connectivity to users, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phones, tablet computers, laptop computers, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in autonomous 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, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, wearable devices, terminal devices in 5G networks or future evolved public land mobile communication networks (PLMNs). The present application does not limit this to terminal devices in the PLMN. In vehicle-to-vehicle communication, the communication terminal on a vehicle is a terminal device, and a roadside unit (RSU) can also be a terminal device. A drone with a communication terminal on board can also be considered a terminal device.

[0151] The terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for wearable devices that use wearable technology to intelligently design and develop wearable devices for everyday wear, such as glasses, gloves, watches, clothing, and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not just hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are full-featured, large in size, and can achieve full or partial functions without relying on smartphones, such as smart watches or smart glasses, as well as those that focus on a certain type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0152] The terminal device can also be a terminal device in the Internet of Things (IoT) system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network that interconnects people and machines and things.

[0153] A network device in a communication system can be a device that can communicate with a terminal device. This network device can also be called an access network device or a radio access network device. For example, the network device can be a base station. A network device can also refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station may broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNodeB (MeNB), secondary eNodeB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. A base station may also refer to a communication module, modem, or chip used to be installed in the aforementioned devices or apparatuses. A base station may also refer to a mobile switching center, a device that performs base station functions in D2D, V2X, and M2M communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. A base station may support networks with the same or different access technologies. The present invention does not limit the specific technology or device form used by network equipment.

[0154] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0155] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on aircraft, balloons, and satellites. The present invention does not limit the scenarios in which the network equipment and terminal devices are deployed.

[0156] It is understood that in the embodiments of the present application, the execution subject may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples, and the embodiments of the present application may also perform other operations or variations of various operations. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application need to be performed.

[0157] It should be noted that the message names between the devices or the names of the parameters in the messages in the following embodiments of the present application are only examples. Other names may be used in specific implementations, and the embodiments of the present application do not specifically limit this.

[0158] As shown in Figure 14, an embodiment of the present application provides a method for extending the cyclic prefix CP of a demodulation reference signal DMRS, the method including: generating a demodulation reference signal DMRS symbol, the DMRS symbol including an extension field, the extension field including a supplementary cyclic prefix SCP or a cyclic suffix CS; sending a first signal, the first signal including the DMRS symbol.

[0159] Specifically, the method can be applied to a user equipment, where the user equipment generates a DMRS symbol including an extension field, where the extension field includes an SCP or a CS, and then the user equipment sends a first signal to a network device.

[0160] In one possible implementation, before sending the first signal to the network device, the user equipment will also receive control information from the network device. The control information can indicate whether the DMRS symbol generated by the user equipment has an extension field. If it is indicated that it has an extension field, it can also indicate whether the extension field is SCP or CS and the length of the extension field.

[0161] Specifically, the method may also be applied to a network device, where the network device generates a DMRS symbol including an extension field, where the extension field includes an SCP or a CS, and then the network device sends a first signal to a user equipment.

[0162] In one possible implementation, before sending the first signal to the user equipment, the network device will also send control information to the user equipment. The control information can indicate whether the DMRS symbol generated by the network device has an extension field. If it is indicated that it has an extension field, it can also indicate whether the extension field is SCP or CS and the length of the extension field.

[0163] In the embodiment of the present application, the forward extension of the DMRS and the extension amount may be notified to the user equipment in advance by the network device. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to perform CP extension on the DMRS symbol; if it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0164] In an embodiment of the present application, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment, and the control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes an extension field; if the extension field is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the extension field.

[0165] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether the extended field is included and, if so, the length of the extended field. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple extended fields. The length of the extended field indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether the extended field is included or, if it is determined that the extended field is included, may also indicate the extended length, i.e., the length of the extended field.

[0166] In an embodiment of the present application, when specifically indicating the length of the extended field, the control information can directly indicate the length of the extended field. In addition, it can also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, and the length can be a length identifier such as a symbol or a serial number. The second control information contains specific candidate length information. For example, the candidate length information can be in the form of a length table, and each length corresponds one-to-one to a length identifier such as a symbol or a serial number. The user equipment can determine the specific length of the extended field through the extended field length and the candidate length information in the first control information.

[0167] By adding an extension field in the DMRS symbol, the CP of the DMRS symbol is losslessly extended.

[0168] The following are some examples:

[0169] In the embodiments of the present application, embodiments 1 to 5 are cases where a user equipment sends a DMRS symbol to a network device, which are described in detail below:

[0170] Example 1:

[0171] As shown in FIG15 , a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS) provided in the present application is provided. In the case where the demodulation reference signal (DMRS) is located at the head of a first signal, that is, the DMRS is the first symbol in the first signal, and the first signal is located on a physical uplink shared channel (PUSCH), the method includes:

[0172] The user equipment transmits a first signal to the network device. The first signal includes a demodulation reference signal (DMRS). The DMRS includes a CP and a supplementary cyclic prefix (SCP). As shown in Figure 15, the SCP of the DMRS symbol is the same as the first field. The first field is included in the DMRS symbol. The cutoff point of the first field is the cyclic prefix (CP) interception point of the DMRS symbol. The supplementary cyclic prefix (SCP), CP, and DMRS data block of the DMRS are arranged in sequence. The equivalent CP of the DMRS includes the original CP and SCP.

[0173] In this embodiment, as shown in Figure 16, the tail field of the second symbol overlaps with the SCP in time, the length of the overlapping part is the length of the SCP, the second symbol is included in the second signal, the cutoff point of the tail field of the second symbol is the cutoff point of the second symbol, and the next sampling point of the cutoff point of the tail field of the second symbol is the starting point of the CP of the DMRS symbol.

[0174] In this embodiment, the network device may inform the user equipment in advance of the forward extension of the DMRS and the extension amount (i.e., the length of the SCP). Forward extension means that the supplementary cyclic prefix SCP is located before the CP of the DMRS. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to perform CP extension on the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0175] For example, in this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes SCP; if SCP is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the SCP.

[0176] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether to send the SCP or the length of the SCP. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple SCPs. The length of the SCP indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether to include the SCP or, if it is determined that the SCP is included, may also indicate an extended length, i.e., the length of the SCP.

[0177] In an embodiment of the present application, when specifically indicating the length of the SCP, the control information may directly indicate the length of the SCP. In addition, it may also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the SCP, and the length may be a length identifier such as a symbol or a sequence number. The second control information contains specific candidate length information. For example, the candidate length information may be in the form of a length table, and each length corresponds to a length identifier such as a symbol or a sequence number. The user equipment can determine the specific length of the extended field through the SCP length and the candidate length information in the first control information.

[0178] In the subsequent embodiments, the manner in which the network device sends control information to the user equipment is the same as the above manner, and will not be described in detail.

[0179] In this embodiment, the timing advance TA of the user equipment UE needs to be added with the length of the supplementary cyclic prefix SCP, that is, TA = 2*t prop +t offset +T SCP ;

[0180] Among them, T SCP The TA can inform the UE via TAC.

[0181] In this embodiment, the DMRS overlaps with the previous symbol in the time domain, and the overlapping portion is the length of the SCP.

[0182] In this embodiment, the length of the supplementary cyclic prefix SCP may be affected by the following factors:

[0183] Factor 1: The maximum channel delay spread (MDS) and CP length difference. To ensure lossless DMRS channel estimation performance, the length of the SCP plus the CP must be no less than the MDS.

[0184] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the SCP plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the SCP plus the CP can also be less than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the SCP can be less than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the SCP can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0185] Factor 3: Interference of SCP on the previous symbol. From the perspective of the network equipment, the DMRS symbol overlaps with the second symbol, and the size of the overlapping range is equal to the length of the SCP, as shown in the dotted box marked "SCP" in Figure 16. Therefore, the SCP will fall into the RX FFT window of the second symbol, resulting in ISI, affecting certain performance of the second symbol, such as demodulation performance. The longer the SCP, the better the channel estimation performance, but the greater the impact of ISI on the second symbol. Therefore, there is a trade-off between the improvement of the channel estimation performance of the DMRS symbol and the deterioration of the performance of the DMRS symbol on the second symbol. If the second symbol has weak anti-ISI capability or the performance is required to be unaffected by ISI, the length of the SCP is limited. If there is a redundant signal at the end of the second symbol, such as a zero signal as a guard band to reduce the impact of SCP on the second symbol, the length of the SCP cannot exceed the length of the redundant signal.

[0186] In this embodiment, the tail signal of the second symbol can be made a redundant signal in a variety of ways, such as unique word DFT-s-OFDM, zero tail DFT-s-OFDM, unique word OFDM, zero tail OFDM, etc. The tail signal in this embodiment is a redundant signal, and the receiving end does not need to demodulate it, and its demodulation performance does not need to be considered.

[0187] The cost of introducing redundant signals is reduced spectral efficiency, as they carry no valid information. Equivalently, under spectrum efficiency alignment, the increase in redundant signal overhead is equivalent to an increase in code rate. The demodulation SNR improves with increasing code rate. The degree of spectral efficiency degradation or code rate increase is related to the payload size of the other user's PUSCH. The larger the payload, the smaller the degradation in spectral efficiency. Assume that redundant signals correspond to 10 fewer modulation symbols being transmitted. If the other user's PUSCH payload carries 1000 modulation symbols without redundant signals, the redundant signals result in a 1% loss in frequency domain efficiency. If the other user's PUSCH payload carries 100 modulation symbols without redundant signals, the redundant signals result in a 10% loss in frequency domain efficiency. Therefore, when the payload is small, the SCP length should also be smaller. It should be understood that payload can also refer to the number of information bits carried by the PUSCH.

[0188] In this embodiment, as shown in FIG16 , the length of the partial signal where the DMRS symbol falls within the RX FFT window of the second symbol is equal to the MDS-CP and has nothing to do with the SCP.

[0189] In this embodiment, by adding SCP to the DMRS symbol, the CP of the DMRS symbol is losslessly extended.

[0190] Example 2:

[0191] As shown in FIG17 , a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS) provided in the present application is provided. When the demodulation reference signal (DMRS) is located at the head of a first signal, and the first signal is located on a physical uplink shared channel (PUSCH), the method includes:

[0192] The user equipment transmits a first signal to the network device, the first signal including a demodulation reference signal (DMRS). The DMRS includes a normal cyclic prefix (CP) and a supplementary cyclic prefix (SCP). Similar to the first embodiment, as shown in FIG17 , the SCP of the DMRS symbol is the same as the first field, the first field is included in the DMRS symbol, and the cutoff point of the first field is the cyclic prefix (CP) interception point of the DMRS symbol. As shown in FIG17 , the normal cyclic prefix (CP) of the DMRS, the supplementary cyclic prefix (SCP), and the data block of the DMRS are arranged in sequence.

[0193] In this embodiment, the excess portion of the DMRS symbol is located behind the DMRS symbol, and is therefore called CP backward extension.

[0194] In this embodiment, unlike the first embodiment, the DMRS does not overlap with the previous symbol in the time domain, and the received DMRS does not overlap with the second symbol. Meanwhile, the DMRS only causes ISI to the next symbol (called the third symbol).

[0195] It can also be understood that compared with the DMRS in the first embodiment, the DMRS symbol is shifted backward as a whole, and the shift amount is equal to the length of the SCP.

[0196] In this embodiment, the RX FFT window corresponding to the DMRS symbol is shifted backward by the length of the SCP relative to the TX IFFT window.

[0197] In this embodiment, the equivalent CP length of the third symbol is T CP -T SCP , instead of T CP , to keep the PUSCH length unchanged.

[0198] In this embodiment, the header field of the third symbol is replaced by the tail field of the DMRS symbol, the starting point of the header field of the third symbol is the starting point of the third symbol, the end point of the tail field of the DMRS symbol is the end point of the DMRS symbol, the third symbol is the next symbol after the DMRS symbol in the first signal, and the length of the replaced part of the third symbol is the length of the SCP.

[0199] In this embodiment, TA does not need to be adjusted.

[0200] In this embodiment, the network device may inform the user equipment in advance whether the CP of the DMRS is extended and the extension amount (i.e., the length of the SCP). Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to extend the CP of the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0201] In this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes SCP; if SCP is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the SCP.

[0202] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether the SCP is included and, if the extension field is included, also indicates the length of the SCP. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple SCPs. The length of the SCP indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether the SCP is included or, if the SCP is included, may also indicate the extended length, i.e., the length of the SCP.

[0203] In this embodiment, when specifically indicating the length of the SCP, the control information may directly indicate the length of the SCP. In addition, the indication may also be performed in other ways. For example, the first control information indicates the length of the SCP, and the length may be a length identifier such as a symbol or a sequence number. The second control information contains specific candidate length information. For example, the candidate length information may be in the form of a length table, where each length corresponds to a length identifier such as a symbol or a sequence number. The user equipment may determine the specific length of the SCP based on the SCP length and the candidate length information in the first control information.

[0204] In this embodiment, the length of the supplementary cyclic prefix SCP may be affected by the following factors:

[0205] Factor 1: The maximum channel delay spread (MDS) and CP length difference. To ensure lossless DMRS channel estimation performance, the length of the SCP plus the CP must be no less than the MDS.

[0206] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the SCP plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the SCP plus the CP can also be less than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the SCP can be less than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the SCP can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0207] Factor 4: Interference level of DMRS on the third symbol. A signal of the DMRS symbol with a length of MDS-CP+SCP falls within the RX FFT window of the third symbol (as shown in the dotted box in Figure 17), causing ISI. The longer the SCP, the greater the impact of ISI on the third symbol. Considering that the third symbol has limited ability to resist ISI, the length of SCP is limited. On the other hand, the CP length of the third symbol is reduced from the original CP to the length of CP-SCP. Compared with Example 1, the degree of CP deficiency is more serious and the ICI suffered is more severe. The ability of the third symbol to resist ISI and ICI is related to the modulation and coding scheme (MCS) or EVM. When the MCS or EVM is below a certain threshold, the SCP length can be longer.

[0208] Example 3:

[0209] As shown in FIG18 , a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS) provided in the present application is provided. When the demodulation reference signal (DMRS) is located at the head of a first signal, and the first signal is located on a physical uplink shared channel (PUSCH), the method includes:

[0210] The user equipment transmits a first signal to the network device, the first signal including a demodulation reference signal (DMRS), the DMRS including a regular cyclic prefix (CP) and a cyclic suffix (CS). As shown in FIG18 , when the extended field is a CS, the CS is the same as the second field, the second field is included in the DMRS symbol, the starting point of the second field is the next sampling point after the end position of the CP of the DMRS symbol, and the regular cyclic prefix (CP) of the DMRS, the data block of the DMRS, and the cyclic suffix (CS) of the DMRS are arranged in sequence. The equivalent CP length of the DMRS is the original CP plus the CS.

[0211] In this embodiment, as shown in FIG19 , the header signal of the third symbol is replaced with CS, the starting point of the header signal of the third symbol is the starting point of the third symbol, and the third symbol is the symbol after the DMRS symbol in the first signal.

[0212] In this embodiment, TA does not need to be adjusted. The equivalent CP length of the third symbol is T CP -T SCP , instead of T CP , to maintain the PUSCH length. From the network equipment's perspective, the received DMRS does not overlap with the second symbol, as shown in Figure 19. Furthermore, DMRS only causes ISI on the third symbol. The RX FFT window corresponding to the DMRS symbol is shifted back by the length of the CS relative to the TX IFFT window.

[0213] In this embodiment, the DMRS CP extension and the extension amount may be notified to the user equipment in advance by the network device. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to extend the CP of the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0214] In this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes CS; if CS is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of CS.

[0215] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether a CS is included and, if an extension field is included, also indicates the length of the CS. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple CSs. The CS length indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether a CS is included or, if a CS is included, may also indicate the extended length, i.e., the length of the CS.

[0216] In this embodiment, when specifically indicating the length of the CS, the control information can directly indicate the length of the CS. In addition, it can also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the CS, and the length can be a length identifier such as a symbol or a serial number. The second control information contains specific candidate length information. For example, the candidate length information can be in the form of a length table, and each length corresponds one-to-one to a length identifier such as a symbol or a serial number. The user equipment can determine the specific CS length through the CS length and candidate length information in the first control information.

[0217] In this embodiment, factors affecting the design of CS length include:

[0218] Factor 1: The maximum channel delay spread (MDS) and CP length difference. To ensure lossless DMRS channel estimation performance, the length of the CS plus the CP must be no less than the MDS.

[0219] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the CS plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the CS plus the CP can also be lower than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the CS can be lower than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the CS can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0220] Factor 4: The interference level of DMRS on the third symbol. A signal of the DMRS symbol with a length of MDS-CP+CS falls within the RX FFT window of the third symbol, causing ISI. The longer the CS, the greater the impact of ISI on the third symbol. Considering that the third symbol has limited ability to resist ISI, the length of CS is limited. On the other hand, the CP length of the third symbol is reduced from the original CP to the length of CP-CS. Compared with Example 1, the degree of under-CP is more serious and the ICI suffered is more severe. The ability of the third symbol to resist ISI and ICI is related to the modulation and coding scheme (MCS) or EVM. When the MCS or EVM is below a certain threshold, the CS length can be longer.

[0221] Example 4:

[0222] As shown in FIG20 , a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS) provided in the present application is provided. When the demodulation reference signal (DMRS) is located in the middle or end of a first signal, and the first signal is located on a physical uplink shared channel (PUSCH), the method includes:

[0223] The user equipment transmits a first signal to the network device, the first signal including a demodulation reference signal (DMRS). The DMRS includes a normal cyclic prefix (CP) and a supplementary cyclic prefix (SCP). Similar to the first embodiment, as shown in FIG20 , the SCP of the DMRS symbol is the same as the first field, the first field is included in the DMRS symbol, and the cutoff point of the first field is the cyclic prefix (CP) interception point of the DMRS symbol. As shown in FIG20 , the supplementary cyclic prefix (SCP), the normal cyclic prefix (CP) of the DMRS, and the data block of the DMRS are arranged in sequence.

[0224] In this embodiment, the demodulation reference signal uses a new forward extension method. The tail signal of the symbol preceding the DMRS symbol (called the fourth symbol) is a redundant signal, such as a zero signal, as shown in Figure 20. Puncturing is used to place the SCP at the redundant signal position. In this solution, the TA does not need to be adjusted.

[0225] In this embodiment, the tail field of the fourth symbol is replaced with SCP, and the cutoff point of the tail field of the fourth symbol is the cutoff point of the fourth symbol.

[0226] In this embodiment, the DMRS CP extension and the extension amount may be notified to the user equipment in advance by the network device. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to extend the CP of the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0227] In this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes SCP; if SCP is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the SCP.

[0228] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether the SCP is included and, if the extension field is included, also indicates the length of the SCP. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple SCPs. The length of the SCP indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether the SCP is included or, if the SCP is included, may also indicate the extended length, i.e., the length of the SCP.

[0229] In this embodiment, when specifically indicating the length of the SCP, the control information may directly indicate the length of the SCP. In addition, the indication may also be performed in other ways. For example, the first control information indicates the length of the SCP, and the length may be a length identifier such as a symbol or a sequence number. The second control information contains specific candidate length information. For example, the candidate length information may be in the form of a length table, where each length corresponds to a length identifier such as a symbol or a sequence number. The user equipment may determine the specific length of the SCP based on the SCP length and the candidate length information in the first control information.

[0230] Regarding the previous symbol, its CP may be added after adding the SCP, thereby obtaining the fourth symbol as shown in FIG. 20 .

[0231] In this embodiment, factors affecting the design of SCP length include:

[0232] Factor 1: The maximum channel delay spread (MDS) and CP length difference. To ensure lossless DMRS channel estimation performance, the length of the SCP plus the CP must be no less than the MDS.

[0233] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the SCP plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the SCP plus the CP can also be less than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the SCP can be less than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the SCP can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0234] Factor 3: Interference of SCP on the fourth symbol. From the perspective of network equipment, the SCP will fall into the RX FFT window of the fourth symbol, resulting in ISI, which affects certain performance of the fourth symbol, such as demodulation performance. The longer the SCP, the better the channel estimation performance, but the greater the impact of ISI on the fourth symbol. Therefore, there is a trade-off between the improvement in the channel estimation performance of the DMRS symbol and the deterioration in the performance of the DMRS symbol on the fourth symbol. If the fourth symbol has weak anti-ISI capability or the performance is required to be unaffected by ISI, the length of the SCP is limited. If the tail of the fourth symbol has a redundant signal, such as a zero signal as a guard band to reduce the impact of SCP on the fourth symbol, the length of the SCP cannot exceed the length of the redundant signal.

[0235] In the case where the DMRS is not the last symbol of the PUSCH, the DMRS in this embodiment may also be the same backward extension as in the second and third embodiments, which will not be described in detail here.

[0236] Embodiment 5:

[0237] As shown in FIG21 , a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS) provided by the present application includes:

[0238] DMRS is the first symbol of PUSCH; the symbol before the DMRS symbol is GP. At this time, PUSCH is located in the S time slot (as shown in Figure 11).

[0239] The user equipment transmits a first signal to the network device, the first signal including a demodulation reference signal (DMRS). The DMRS includes a normal cyclic prefix (CP) and a supplementary cyclic prefix (SCP). Similar to the first embodiment, as shown in FIG15 , the SCP of the DMRS symbol is the same as the first field, the first field is included in the DMRS symbol, and the cutoff point of the first field is the cyclic prefix (CP) interception point of the DMRS symbol. As shown in FIG21 , the supplementary cyclic prefix (SCP), the normal cyclic prefix (CP) of the DMRS, and the data block of the DMRS are arranged in sequence.

[0240] In this embodiment, as shown in FIG21 , the SCP is located in the GP before the DMRS symbol.

[0241] In this embodiment, the user equipment UE does not need to indicate that the CP can be directly extended forward, that is, the network device does not need to send control information to the user equipment, thereby saving signaling overhead.

[0242] In this embodiment, the timing advance TA of the user equipment UE needs to be added with the length of the supplementary cyclic prefix SCP, that is, TA = 2*t prop +t offset +T SCP ;

[0243] The UE determines whether the symbol preceding a DMRS symbol is a GP symbol as follows: First, the UE can learn the tdd-UL-DL-Configuration through a broadcast message, thereby knowing the number of downlink symbols, uplink symbols, and GP symbols in the S time slot. If the UE does not know the tdd-UL-DL-Configuration, the UE can also use other methods to determine that the symbol preceding the DMRS symbol is a GP symbol. For example, the interval between the DMRS symbol and the last downlink symbol is less than or equal to a symbols, where a is a positive integer, such as a = 1, 2, 3, 4, .... The last downlink symbol may be located in the PDCCH that schedules the UE.

[0244] In this embodiment, factors affecting the design of SCP length include:

[0245] Factor 1: The maximum channel delay spread (MDS) and CP length difference. To ensure lossless DMRS channel estimation performance, the length of the SCP plus the CP must be no less than the MDS.

[0246] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the SCP plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the SCP plus the CP can also be less than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the SCP can be less than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the SCP can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0247] Factor 5: The uplink signal in the SCP cannot conflict with the downlink signal previously sent by the GP, so the length of the SCP is limited. The maximum transmission delay of the downlink signal within the coverage area of ​​the network device is defined as τ TD,max , and the maximum delay spread of the downlink signal is τ MDS , define the total duration of all GPs in S time slot as t GP A possible condition for the uplink signal in SCP to not conflict with the downlink signal previously sent by GP is: SCP <t GP -2τ TD,max -τ MDS -τ tr , where τ tr Some other delays including UE transmit / receive conversion delay.

[0248] In the embodiments of the present application, embodiments 6 to 8 are cases where a network device sends DMRS symbols to a user equipment, which are described in detail below:

[0249] Example 6:

[0250] The present application provides a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS). When the demodulation reference signal (DMRS) is located at the head or middle of a first signal, and the first signal is located on a physical downlink shared channel (PDSCH), the method includes:

[0251] A network device sends a first signal to a user equipment. The first signal includes a demodulation reference signal (DMRS) symbol. The DMRS symbol may include a supplementary cyclic prefix (SCP) or a cyclic suffix (CS).

[0252] In this embodiment, when the DMRS symbol is located at the head of the PDSCH, the network device may extend the CP of the DMRS symbol in any of the methods in the second embodiment or the third embodiment, and the details will not be repeated here.

[0253] In this embodiment, when the DMRS symbol is located in the middle of the PDSCH, the network device may extend the CP of the DMRS symbol according to any one of the methods in the second embodiment, the third embodiment, or the fourth embodiment, and the details are not repeated here.

[0254] In this embodiment, the network device may instruct the UE on the extension method and extension amount.

[0255] In this embodiment, the DMRS CP extension and the extension amount may be notified to the user equipment in advance by the network device. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to extend the CP of the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0256] In this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes an extension field; if the extension field is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the extension field.

[0257] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether the extended field is included and, if so, the length of the extended field. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple extended fields. The length of the extended field indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether the extended field is included or, if it is determined that the extended field is included, may also indicate the extended length, i.e., the length of the extended field.

[0258] In this embodiment, when specifically indicating the length of the extended field, the control information can directly indicate the length of the extended field. In addition, it can also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, and the length can be a length identifier such as a symbol or a serial number. The second control information contains specific candidate length information. For example, the candidate length information can be in the form of a length table, and each length corresponds one-to-one to a length identifier such as a symbol or a serial number. The user equipment can determine the specific length of the extended field through the extended field length and the candidate length information in the first control information.

[0259] Embodiment seven:

[0260] As shown in FIG22 , the present application provides a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS). When the demodulation reference signal (DMRS) is located at the end of a first signal and the first signal is located on a physical downlink shared channel (PDSCH), the method includes:

[0261] A network device sends a first signal to a user equipment. The first signal includes a demodulation reference signal (DMRS). The DMRS may include a supplementary cyclic prefix (SCP) or a cyclic suffix (CS).

[0262] The PDSCH is located in the S time slot, and the next symbol of the DMRS (ie, the third symbol) is a GP. The DMRS CP is extended using the method of the second embodiment or the third embodiment.

[0263] From the perspective of the network device, a portion of the DMRS symbol is located within the GP, as shown in Figure 22. The network device can instruct the UE on the extension method and amount.

[0264] In this embodiment, the DMRS CP extension and the extension amount may be notified to the user equipment in advance by the network device. Specifically, the network device may send control information to the user equipment, where the control information is used to instruct the user equipment whether to extend the CP of the DMRS symbol. If it is determined to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0265] In this embodiment, before the user equipment generates the first signal, the user equipment will also receive control information from the network equipment. The control information may include first control information and second control information. The first control information is carried by downlink control information DCI and is used to indicate whether the DMRS symbol includes an extension field; if the extension field is included, the second control information is carried by media access control element MAC-CE signaling or radio resource control RRC signaling and is used to indicate the length of the extension field.

[0266] In addition, the control information may include first control information and second control information. The first control information is carried via DCI and indicates whether the extended field is included and, if so, the length of the extended field. The second control information is carried via MAC-CE signaling or RRC signaling and includes a set of candidate lengths for multiple extended fields. The length of the extended field indicated by the first control information is included in the set of candidate lengths. That is, the first control information may indicate whether the extended field is included or, if it is determined that the extended field is included, may also indicate the extended length, i.e., the length of the extended field.

[0267] In this embodiment, when specifically indicating the length of the extended field, the control information can directly indicate the length of the extended field. In addition, it can also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, and the length can be a length identifier such as a symbol or a serial number. The second control information contains specific candidate length information. For example, the candidate length information can be in the form of a length table, and each length corresponds one-to-one to a length identifier such as a symbol or a serial number. The user equipment can determine the specific length of the extended field through the extended field length and the candidate length information in the first control information.

[0268] In this embodiment, factors affecting the design of the extended field length include:

[0269] Factor 1: The difference between the maximum channel delay spread (MDS) and the CP length. To ensure lossless DMRS channel estimation performance, the length of the extended field (SCP or CS) plus the CP must be no less than the MDS.

[0270] Factor 2: PDSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of the extended field plus the CP needs to be no less than the MDS. In an actual noisy environment, the length of the extended field plus the CP can also be lower than the MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. In this case, the length of the extended field can be lower than the difference between the lengths of the MDS and the CP. For example, when the MDS is four times the length of the CP, the length of the extended field can be twice or even one times the length of the CP. Although this design causes the received DMRS symbols to be affected by some inter-symbol interference (ISI) or inter-carrier interference (ICI), it is much weaker than the noise, and the channel estimation accuracy is negligibly affected.

[0271] Factor 6: Downlink signals in SCP or CS cannot conflict with uplink signals after GP, so the length of SCP or CS is limited. Define the maximum transmission delay of downlink signals within the coverage area of ​​network equipment as τTD,max , and the maximum delay spread of the downlink signal is τ MDS , define the total duration of all GPs in S time slot as t GP A possible condition for the downlink signal in SCP or CS to not conflict with the downlink signal after GP is: SCP <t GP -2τ TD,max -τ MDS -τ tr or T CS <t GP -2τ TD,max -τ MDS -τ tr , where τ tr Some other delays including UE transmit / receive conversion delay.

[0272] Embodiment 8:

[0273] The present application provides a method for extending a cyclic prefix (CP) of a demodulation reference signal (DMRS). When the demodulation reference signal (DMRS) is located at the head of a first signal, and the first signal is located on a physical downlink shared channel (PDSCH), the method includes:

[0274] A network device sends a first signal to a user equipment. The first signal includes a demodulation reference signal (DMRS). The DMRS may include a supplementary cyclic prefix (SCP) or a cyclic suffix (CS).

[0275] In this embodiment, the demodulation reference signal DMRS is located at the head of the physical uplink shared channel PDSCH, and the tail signal of a symbol (belonging to other UEs) before the DMRS is a redundant signal. The network device can extend the DMRS CP according to the method of embodiment 4.

[0276] Compared with Example 6, in this embodiment, because the operation of adding SCP is transparent to the UE, that is, the UE can receive DMRS symbols in a non-SCP manner, the network device does not need to instruct the UE on the extension method and extension amount, that is, the network device does not need to send control information to the user equipment, thereby saving signaling overhead.

[0277] In summary, for the physical uplink shared channel PUSCH, when the DMRS symbol is located at the first symbol or the middle symbol, the CP can be extended forward or backward; when the DMRS symbol is located at the end, the CP can be extended forward as shown in Example 4.

[0278] For the physical downlink shared channel PDSCH, DRMS ​​symbols can be extended forward or backward.

[0279] In an embodiment of the present application, when a DMRS symbol can be extended in multiple ways, the network device or user equipment can select a CP extension method based on the importance level of the previous symbol and the next symbol of the DMRS symbol and the multi-user DMRS symbol multiplexing method.

[0280] In the embodiment of the present application, the higher the symbol importance level, the higher the level of symbol importance. In order to ensure that the demodulation or symbol-based parameter estimation performance is not affected, the high-level symbol is required to be free of interference or subject to very little interference. High-level symbols include synchronization symbols (such as primary synchronization symbols and secondary synchronization symbols), reference symbols (such as demodulation reference signals and channel state information reference signals), control symbols (such as physical downlink control channel symbols and physical uplink control channel symbols), and high-reliability symbols.

[0281] For low-level symbols, such as ordinary data symbols, if the MCS exceeds a certain threshold or the EVM is lower than a certain threshold, the symbol's anti-interference capability is weak.

[0282] For low-level symbols, such as ordinary data symbols, where the MCS is lower than a certain threshold or the EVM is higher than a certain threshold, the symbols can withstand certain interference.

[0283] The DMRS symbol extension direction should be towards the symbol with strong anti-interference ability. Taking the PUSCH DMRS symbol as an example, assuming that the next DMRS symbol has strong anti-ISI ability, the backward extension solution can be adopted.

[0284] In addition, the DMRS symbol extension direction is also related to the multi-user DMRS symbol multiplexing method. If DMRS belonging to different UEs are frequency-division multiplexed and occupy the same time resources, the DMRS CP is extended forward to avoid degrading the channel estimation performance of the DMRS of other UEs.

[0285] In the embodiments of the present application, for embodiments that require a network device to instruct the UE, such as implementations 1-4 and embodiments 6-7, the network device can implement this by sending control information such as MAC CE and / or RRC signaling to the UE through a downlink physical control channel.

[0286] In the embodiment of the present application, lossless extension of the DMRS symbol can be achieved by forward extension or backward extension of the DMRS symbol.

[0287] The embodiment of the present application provides a user device 2300. In the embodiment of the present application, the user device 2300 can be divided into functional modules according to the above method example. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of a software functional module. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0288] In the case of dividing each functional module according to each function, FIG23 shows a possible structural diagram of the user equipment 2300 involved in the above embodiment. As shown in FIG23, the user equipment 2300 includes:

[0289] The receiving module 2301 is configured to receive control information sent by a network device, where the control information indicates: the length of the SCP; or the length of the CS; or the extension field is the SCP or CS and the length of the extension field.

[0290] The generating module 2302 is configured to generate a demodulation reference signal (DMRS) symbol, where the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix (SCP) or a cyclic suffix (CS).

[0291] The sending module 2303 is configured to send a first signal to a network device, where the first signal includes a DMRS symbol.

[0292] The modules of the user equipment may also be used to perform other actions in the method embodiment. All relevant contents of the steps involved in the method embodiment may be referred to the functional description of the corresponding functional modules and will not be repeated here.

[0293] The embodiment of the present application provides another user device 2400. In the embodiment of the present application, the user device 2400 can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0294] In the case of dividing each functional module according to each function, FIG24 shows a possible structural diagram of the user equipment 2400 involved in the above embodiment. As shown in FIG24, the user equipment 2400 includes:

[0295] The first receiving module 2401 is configured to receive control information sent by a network device, where the control information indicates: the length of an SCP; or the length of a CS; or the extension field is an SCP or a CS and the length of the extension field.

[0296] The second receiving module 2401 is configured to receive a first signal, where the first signal includes a DMRS symbol, the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS.

[0297] The modules of the user equipment may also be used to perform other actions in the method embodiment. All relevant contents of the steps involved in the method embodiment may be referred to the functional description of the corresponding functional modules and will not be repeated here.

[0298] The embodiment of the present application provides a network device 2500. In the embodiment of the present application, the network device 2500 can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0299] In the case of dividing each functional module into corresponding functional modules, FIG25 shows a possible structural diagram of the network device 2500 involved in the above embodiment. As shown in FIG25 , the network device 2500 includes:

[0300] A sending module 2501 is configured to send control information, where the control information indicates: the length of the supplementary cyclic prefix (SCP); or the length of the cyclic suffix (CS); or whether the extended field is the SCP or the CS and the length of the extended field;

[0301] The receiving module 2502 is configured to receive a first signal, where the first signal includes a demodulation reference signal (DMRS) symbol, the DMRS symbol includes an extension field, and the extension field includes an SCP or a CS.

[0302] The various modules of the above-mentioned network device can also be used to perform other actions in the above-mentioned method embodiment. All relevant contents of each step involved in the above-mentioned method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0303] The embodiment of the present application provides another network device 2600. In the embodiment of the present application, the network device 2600 can be divided into functional modules according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present invention is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0304] In the case of dividing each functional module according to each function, FIG26 shows a possible structural diagram of the network device 2600 involved in the above embodiment. As shown in FIG26 , the network device 2600 includes:

[0305] A generating module 2601 is configured to generate a demodulation reference signal (DMRS) symbol, where the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix (SCP) or a cyclic suffix (CS);

[0306] The first sending module 2602 is configured to send control information, where the control information indicates: the length of the supplementary cyclic prefix (SCP); or the length of the cyclic suffix (CS); or the extension field being the SCP or CS and the length of the extension field;

[0307] The second sending module 2603 is configured to send a first signal, where the first signal includes a demodulation reference signal (DMRS) symbol, the DMRS symbol includes an extension field, and the extension field includes an SCP or a CS.

[0308] The various modules of the above-mentioned network device can also be used to perform other actions in the above-mentioned method embodiment. All relevant contents of each step involved in the above-mentioned method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0309] Figure 27 is a schematic diagram of the structure of a user device provided in an embodiment of the present application. The user device 2700 may include one or more central processing units (CPU) 2701 and a memory 2705. The memory 2705 stores one or more applications or data.

[0310] Memory 2705 may be volatile or persistent storage. The program stored in memory 2705 may include one or more modules, each of which may include a series of instruction operations on the user device. Furthermore, central processing unit 2701 may be configured to communicate with memory 2705 and execute the series of instruction operations in memory 2705 on user device 2700.

[0311] The central processor 2701 is configured to execute the computer program in the memory 2705, so that the user equipment 2700 is configured to: generate a demodulation reference signal (DMRS) symbol, where the DMRS symbol includes an extension field, where the extension field includes a supplementary cyclic prefix (SCP) or a cyclic suffix (CS); and transmit a first signal, where the first signal includes the DMRS symbol. Or, the central processor 2701 is configured to: receive a first signal, where the first signal includes a DMRS symbol, where the DMRS symbol includes an extension field, where the extension field includes a supplementary cyclic prefix (SCP) or a cyclic suffix (CS).

[0312] The user device 2700 may also include one or more power supplies 2702, one or more wired or wireless network interfaces 2703, one or more input and output interfaces 2704, and / or one or more operating systems, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0313] The user equipment 2700 can perform the operations performed by the user equipment in the aforementioned embodiments, and the details will not be repeated here.

[0314] FIG28 is a schematic diagram of a network device structure provided in an embodiment of the present application. The network device 2800 may include one or more central processing units (CPUs) 2801 and a memory 2805 , wherein the memory 2805 stores one or more applications or data.

[0315] Memory 2805 may be volatile or persistent storage. The program stored in memory 2805 may include one or more modules, each of which may include a series of instruction operations on the network device. Furthermore, central processing unit 2801 may be configured to communicate with memory 2805 and execute the series of instruction operations in memory 2805 on network device 2800.

[0316] The central processor 2801 is configured to execute the computer program in the memory 2805, so that the network device 2800 is configured to execute: the network device sends control information, where the control information indicates: the length of the supplementary cyclic prefix (SCP); or the length of the cyclic suffix (CS); or the extension field is the SCP or CS and the length of the extension field. Or, the network device 2800 is configured to execute: the network device generates a demodulation reference signal (DMRS) symbol, where the DMRS symbol includes an extension field, where the extension field includes the supplementary cyclic prefix (SCP) or the cyclic suffix (CS); and the network device sends a first signal, where the first signal includes the DMRS symbol.

[0317] The network device receives a first signal, where the first signal includes a demodulation reference signal (DMRS) symbol, the DMRS symbol includes an extension field, and the extension field includes an SCP or a CS.

[0318] The network device 2800 may also include one or more power supplies 2802, one or more wired or wireless network interfaces 2803, one or more input and output interfaces 2804, and / or one or more operating systems, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0319] The network device 2800 can execute the operations executed by the network devices in the aforementioned embodiments, and the details will not be repeated here.

[0320] Figure 29 is a structural diagram of a communication system provided in an embodiment of the present application. The communication system 2900 includes a user device 2901 and a network device 2902, wherein the user device 2901 can perform the operations performed by the user device in the aforementioned embodiment, and the network device 2902 can perform the operations performed by the network device in the aforementioned embodiment. The details are not repeated here.

[0321] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using a software program, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes (or functions) of the embodiments of the present application are implemented. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more media integrated therein. Available media may be magnetic media (eg, floppy disk, hard disk, tape), optical media (eg, DVD), or semiconductor media (eg, solid state disk (SSD)), etc. In the embodiment of the present application, the computer may include the aforementioned device.

[0322] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

Claims

1. A method for extending a demodulation reference signal cyclic prefix, characterized in that: The method comprises: Generate a demodulation reference signal DMRS symbol, wherein the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; A first signal is sent, where the first signal includes the DMRS symbol.

2. The method according to claim 1, characterized in that In the case where the extended field is SCP, the SCP is the same as the first field, the first field is included in the DMRS symbol, and the cutoff point of the first field is a cyclic prefix CP interception point of the DMRS symbol; In the case where the extension field is CS, the CS is the same as the second field, the second field is included in the DMRS symbol, and the starting point of the second field is a sampling point next to the end position of the CP of the DMRS symbol.

3. The method according to claim 1 or 2, characterized in that: The extension field is SCP.

4. The method according to claim 3, characterized in that The DMRS symbol is the first symbol of the first signal.

5. The method according to claim 4, characterized in that The tail field of the second symbol overlaps with the SCP in time, the length of the overlapping part is the length of the SCP, the second symbol is included in the second signal, the cutoff point of the tail field of the second symbol is the cutoff point of the second symbol, and the next sampling point of the cutoff point of the tail field of the second symbol is the starting point of the DMRS symbol CP.

6. The method according to claim 4, characterized in that: The first signal is located in a self-contained time slot, and the SCP of the DMRS symbol is located in a protection period GP.

7. The method according to claim 5 or 6, characterized in that: The first signal is sent in a physical uplink shared channel, and the first signal is sent in advance according to the length of the SCP.

8. The method according to claim 3, characterized in that The DMRS symbol is not the last symbol of the first signal, the header field of the third symbol is replaced by the tail field of the DMRS symbol, the starting point of the header field of the third symbol is the starting point of the third symbol, the end point of the tail field of the DMRS symbol is the end point of the DMRS symbol, the third symbol is the next symbol of the DMRS symbol in the first signal, and the length of the replaced part of the third symbol is the length of the SCP.

9. The method according to claim 3, characterized in that: The tail field of the fourth symbol is replaced by the SCP, the fourth symbol is a symbol preceding the DMRS symbol, and the cutoff point of the tail field of the fourth symbol is the cutoff point of the fourth symbol.

10. The method according to claim 4 or 9, characterized in that: The first signal is transmitted through a physical downlink shared channel.

11. The method according to claim 5 or 9, characterized in that: The tail field of the second symbol is a redundant signal; or the tail field of the fourth symbol is a redundant signal.

12. The method according to claim 1 or 2, characterized in that: The extension field is CS.

13. The method according to claim 12, characterized in that The DMRS symbol is not the last symbol in the first signal, the header field of the third symbol is replaced by the CS, the starting point of the header field of the third symbol is the starting point of the third symbol, and the third symbol is the symbol after the DMRS symbol in the first signal.

14. The method according to claim 12, characterized in that The DMRS symbol is the last symbol in the first signal, the first signal is located in a self-contained time slot, and the CS of the DMRS symbol is located in a protection period GP.

15. The method according to any one of claims 1 to 14, characterized in that: Generating a demodulation reference signal DMRS symbol includes determining, according to the first information, that the extended field is generated as SCP or CS, The first information includes one or more of the following information: The position relationship between the DMRS symbol and the protection period GP; a type of the second symbol, a type of the third symbol, and a type of the fourth symbol; a modulation coding scheme MCS or an error vector magnitude EVM of the second symbol, an MCS or EVM of the third symbol, or an MCS or EVM of the fourth symbol; Multiplexing method of multi-user DMRS symbols.

16. The method according to claim 15, characterized in that: Generating a demodulation reference signal DMRS symbol includes: determining, according to second information, a length of an extended field for generating the DMRS symbol, wherein the second information includes one or more of the following information: A maximum channel delay spread experienced by the first signal; The length of the cyclic prefix CP; An operating signal-to-noise ratio SNR of the first signal; the MCS or EVM of the second symbol, the MCS or EVM of the third symbol, or the MCS or EVM of the fourth symbol.

17. The method according to claim 16, characterized in that: The extension field of the DMRS symbol is located within a protection period GP, and the second information also includes the length of the GP.

18. The method according to any one of claims 1, 2, 3, 4, 5, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, characterized in that: Before generating a demodulation reference signal DMRS symbol, the method further includes: Receive control information, the control information indicating: the length of the SCP; or the length of the CS; or The extension field is SCP or CS and the length of the extension field.

19. The method according to claim 18, characterized in that: The control information includes first control information and second control information, the first control information is carried by downlink control information DCI, and the first control information indicates whether the DMRS symbol includes an extension field; The second control information is carried via media access control element MAC-CE signaling or radio resource control RRC signaling, and the second control information indicates the length of the extension field.

20. The method according to claim 18, characterized in that: The control information includes first control information and second control information, the first control information is carried by DCI, and the first control information indicates whether the DMRS symbol includes an extension field or the length of the extension field; The second control information is carried via MAC-CE signaling or RRC signaling, and includes a plurality of candidate length sets of the extended field, wherein the length of the extended field indicated by the first control information is included in the candidate length set.

21. The method according to claim 19 or 20, characterized in that In a case where the first control information indicates that the DMRS symbol includes an extension field, the first control information further indicates that the extension field is SCP or CS.

22. A method for extending a demodulation reference signal cyclic prefix, characterized in that: The method comprises: The user equipment generates a demodulation reference signal DMRS symbol, where the DMRS symbol includes an extension field, where the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; The user equipment sends a first signal, where the first signal includes the DMRS symbol 23. The method according to claim 22, characterized in that Before the user equipment generates a demodulation reference signal DMRS symbol, the method further includes: The user equipment receives control information, where the control information indicates: the length of the SCP; or the length of the CS; or The extended field is SCP or CS and the length of the extended field, so that the user equipment implements the method according to any one of claims 1-21.

24. A method for extending a demodulation reference signal cyclic prefix, characterized in that: The method comprises: The network device sends control information, wherein the control information indicates: the length of the supplementary cyclic prefix SCP; or the length of the cyclic suffix CS; or The extended field is SCP or CS and the length of the extended field, so that the user equipment implements the method described in any one of claims 1-17. A network device receives a first signal, where the first signal includes a demodulation reference signal (DMRS) symbol, where the DMRS symbol includes an extension field, and where the extension field includes an SCP or a CS.

25. A method for extending a demodulation reference signal cyclic prefix, characterized in that: The method comprises: The network device generates a demodulation reference signal DMRS symbol, wherein the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; The network device sends a first signal, where the first signal includes the DMRS symbol.

26. The method according to claim 25, characterized in that Before the network device sends the first signal, the method further includes: The network device sends a control message, wherein the control information indicates: the length of the SCP; or the length of the CS; or The extended field is SCP or CS and the length of the extended field, so that the user equipment implements the method according to any one of claims 1 to 17.

27. A method for extending a demodulation reference signal cyclic prefix, characterized in that: The method comprises: The user equipment receives a first signal, where the first signal includes a DMRS symbol, where the DMRS symbol includes an extension field, where the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS.

28. The method according to claim 27, characterized in that Before the user equipment receives the first signal, the method further includes: The user equipment receives a control message, wherein the control message indicates: the length of the SCP; or the length of the CS; or The extension field is SCP or CS and the length of the extension field.

29. A user equipment, characterized in that: The user device includes a processor and a memory; the processor is coupled to the memory; the memory is used to store computer instructions, and the computer instructions are loaded and executed by the processor to enable the user device to implement the method described in any one of claims 22, 23, 27 or 28.

30. A network device, characterized in that: The network device includes a processor and a memory; the processor is coupled to the memory; the memory is used to store computer instructions, and the computer instructions are loaded and executed by the processor to enable the network device to implement the method as described in any one of claims 24-26.

31. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one computer program instruction, and the computer program instruction is loaded and executed by the processor to implement the method according to any one of claims 22, 23, 27 or 28.

32. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one computer program instruction, and the computer program instruction is loaded and executed by the processor to implement the method according to any one of claims 24-26.

33. A computer program product, characterized in that The computer program product comprises computer-executable instructions. When the computer-executable instructions are executed on a computer, the computer is configured to implement the method according to any one of claims 22, 23, 27 or 28.

34. A computer program product, characterized in that The computer program product comprises computer-executable instructions. When the computer-executable instructions are executed on a computer, the computer is configured to implement the method according to any one of claims 24 to 26.

35. A communication system, characterized in that: The communication system includes a user device and a network device, the user device is used to execute the method according to any one of claims 22, 23, 27 or 28, and the network device is used to execute the method according to any one of claims 24-26.

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