Demodulation reference signal cyclic prefix extension method and equipment

Abstract

The invention provides a demodulation reference signal cyclic prefix extension method, relates to the technical field of communication, and is used for realizing lossless extension of a demodulation reference signal (DMRS) symbol (CP). The method comprises: generating a demodulation reference signal (DMRS) symbol, the DMRS symbol comprising an extension field, the extension field comprising a supplementary cyclic prefix (SCP) or a cyclic suffix (CS); and transmitting a first signal, wherein the first signal comprises the DMRS symbol.

Description

Technical Field

[0001] 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

[0002] In the existing scheme for extending the cyclic prefix (CP) of the demodulation reference signal (DMRS) symbol, the end signal of the symbol before the demodulation reference signal DMRS is made approximately the same (not strictly the same, there is an error) as the signal at and before the CP interception point in the DMRS, and the end signal of the symbol before the DMRS can be regarded as the supplementary CP (SCP) of the DMRS symbol. At this time, the equivalent CP length of the DMRS is equal to the length of the CP plus the length of the SCP. The above SCP approximation error impairs the channel estimation performance at a high signal to noise ratio (SNR). Summary of the invention

[0003] The embodiment of the present application provides a demodulation reference signal cyclic prefix extension method and device, so that the CP of the DMRS symbol is extended losslessly. The CP lossless extension can be understood as the CP extension part has no (approximate) error.

[0004] 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 comprising an extension field, the extension field comprising a supplementary cyclic prefix SCP or a cyclic suffix CS; sending a first signal, the first signal comprising a DMRS symbol.

[0005] In this possible implementation, an extension field is added to the DMRS symbol so that the CP of the DMRS symbol is losslessly extended.

[0006] In a possible implementation, when 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 the cyclic prefix CP interception point of the DMRS symbol. At this time, the equivalent CP of the DMRS symbol is the SCP and the original CP;

[0007] When the extended field is CS, 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 the next sampling point of the end position of the CP of the DMRS symbol. At this time, the equivalent CP of the DMRS symbol is the original CP and the second field;

[0008] In a possible implementation, the extension field is SCP.

[0009] In a possible implementation manner, the DMRS symbol is the first symbol of the first signal.

[0010] 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.

[0011] In a possible implementation, the tail field of the second symbol is a redundant signal.

[0012] In this possible implementation, when the tail field of the second symbol is a redundant signal, the impact of adding SCP in the DMRS symbol on the demodulation performance of the second symbol is reduced.

[0013] In a possible implementation manner, 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.

[0014] 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.

[0015] In a possible implementation manner, 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.

[0016] 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.

[0017] 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 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.

[0018] 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.

[0019] In a possible implementation manner, the first signal is transmitted through a physical downlink shared channel.

[0020] In a possible implementation, the tail field of the fourth symbol is a redundant signal.

[0021] In this possible implementation, when the tail field of the fourth symbol is a redundant signal, the impact of adding SCP in the DMRS symbol on the demodulation performance of the fourth symbol is reduced.

[0022] In a possible implementation, the extension field is CS.

[0023] 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.

[0024] In a possible implementation manner, 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.

[0025] 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.

[0026] 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, and the first information may include one or more of the following information: a positional relationship between the DMRS symbol and a 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; and a multiplexing method of multi-user DMRS symbols.

[0027] In this possible implementation, it is necessary to generate a DMRS symbol according to the first information, thereby reducing adverse effects on other symbols (which may or may not belong to the first signal).

[0028] 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.

[0029] In this possible implementation, the length of the extension field needs to be determined based on the second information, which reduces the adverse effects on other symbols (which may or may not belong to the first signal). Determining the length of the extension field needs to take into account the maximum channel delay extension experienced by the first signal, which is conducive to achieving lossless channel estimation performance of the DMRS symbol; determining the length of the extension field needs to take into account the working 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).

[0030] In a possible implementation manner, the extension field of the DMRS symbol is located within the protection period GP, and the second information further includes the length of the GP.

[0031] In this possible implementation, the second information also 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.

[0032] 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 is the SCP or the CS and the length of the extension field.

[0033] 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.

[0034] In one possible implementation, the control information includes first control information and second control information, the first control information is carried through DCI, the first control information indicates whether the DMRS symbol includes an extended field and, if included, also indicates the length of the extended field; the second control information is carried through MAC-CE signaling or RRC signaling, the second control information includes a set of candidate lengths of multiple extended fields, and the length of the extended field indicated by the first control information is included in the candidate length set.

[0035] 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.

[0036] 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

[0037] In a possible implementation manner, before the user equipment generates a demodulation reference signal DMRS symbol, the method further includes:

[0038] 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.

[0039] In a third aspect, an embodiment of the present application provides a demodulation reference signal cyclic prefix extension method, the method comprising: a network device sends control information, the control information indicates: the length of a supplementary cyclic prefix SCP; or the length of a cyclic suffix CS; or the extension field is SCP or CS and the length of the extension field. The network device receives a first signal, the first signal includes a demodulation reference signal DMRS symbol, the DMRS symbol includes an extension field, and the extension field includes SCP or CS.

[0040] 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.

[0041] In a possible implementation, before the network device sends the first signal, the method further includes: the network device sends a control message, the control information indicating: 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.

[0042] 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.

[0043] In a possible implementation manner, the method further includes: the user equipment receives 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.

[0044] In a sixth aspect, an embodiment of the present application provides a user device, comprising: 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 any one of the methods provided in the first aspect, the second aspect, or the fifth aspect.

[0045] In a seventh aspect, an embodiment of the present application provides a network device, including: 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 any one of the methods provided in the first aspect, the third aspect, or the fourth aspect.

[0046] 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; 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.

[0047] 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.

[0048] 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 aspect, the second aspect or the fifth aspect above.

[0049] 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.

[0050] In the twelfth aspect, an embodiment of the present application provides a computer program product, including computer execution instructions, which, when executed 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.

[0051] 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.

[0052] The technical effects brought about by any implementation method in the sixth to thirteenth aspects can refer 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

[0053] Figure 1 A schematic diagram of an OFDM / DFT-s-OFDM network architecture;

[0054] Figure 2 A schematic diagram of a scenario of OFDM CP insertion;

[0055] Figure 3 A schematic diagram of a scenario in which the RX FFT window position is moved forward;

[0056] Figure 4 A schematic diagram of a time domain linear convolution single carrier modulation scenario;

[0057] Figure 5 A network architecture diagram of a SC-FDE system block diagram;

[0058] Figure 6 Schematic diagram of a scenario designed for NR PDSCH / PUSCH DMRS;

[0059] Figure 7 A schematic diagram of a scenario of an S time slot;

[0060] Figure 8 A schematic diagram of a scenario with a single-cycle 8:2 time slot ratio;

[0061] Fig. 9 A schematic diagram of a downlink-to-uplink switching scenario;

[0062] Fig.10 A schematic diagram of a scenario of using TA to implement uplink transmission time calibration;

[0063] Fig.11a A schematic diagram of a scenario of forward extension of CP;

[0064] Fig.11b A schematic diagram of a scenario of extending CP backward;

[0065] Fig.12 A schematic diagram of a scenario before DFT replication;

[0066] Fig.13 A schematic diagram of a wireless communication system provided in an embodiment of the present application;

[0067] Fig.14 A schematic diagram of a flow chart of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0068] Fig.15 A schematic diagram of a scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0069] Fig.16 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0070] Fig.17 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0071] Fig.18 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0072] Fig.19 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0073] Fig. 20 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0074] Fig.21 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0075] Fig. 22 A schematic diagram of another scenario of a demodulation reference signal cyclic prefix extension method provided in an embodiment of the present application;

[0076] Fig.23 A schematic diagram of the structure of a user equipment provided in an embodiment of the present application;

[0077] Fig.24 A schematic diagram of the structure of another user equipment provided in an embodiment of the present application;

[0078] Fig.25 A schematic diagram of the structure of a network device provided in an embodiment of the present application;

[0079] Fig.26 A schematic diagram of the structure of another network device provided in an embodiment of the present application;

[0080] Fig. 27 A schematic diagram of the structure of another user equipment provided in an embodiment of the present application;

[0081] Fig.28 A schematic diagram of the structure of another network device provided in an embodiment of the present application;

[0082] Fig.29A schematic diagram of the structure of a communication system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] In the description of this application, unless otherwise specified, " / " indicates that the objects associated with each other 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 between 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.

[0084] 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 items 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 multiple.

[0085] In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same items or similar items with substantially the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference.

[0086] In the embodiments of the present 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 the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0087] It is 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 in the entire 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 is understood that in various embodiments of the present application, the size of the sequence number of each process does not mean the order of execution, and 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.

[0088] It can be understood that some optional features in the embodiments of the present application may be implemented independently in certain scenarios without relying on other features, such as the solution on which they are currently based, to solve corresponding technical problems and achieve corresponding effects, or may be combined with other features according to needs in certain scenarios. Accordingly, the devices provided in the embodiments of the present application may also realize these features or functions accordingly, which will not be elaborated here.

[0089] In this application, unless otherwise specified, the same or similar parts between the various embodiments can refer to each other. In this application, if there is no special description or logical conflict between the various embodiments, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and different embodiments can be combined to form new embodiments according to their inherent logical relationships. The following implementation methods of this application do not constitute a limitation on the scope of protection of this application.

[0090] In order to facilitate understanding of the technical solutions of the embodiments of the present application, a brief introduction to the related technologies of the present application is first given as follows:

[0091] 1. Channels, multipath and delay spread.

[0092] In a radio system, the medium through which a signal travels from a transmitter to a receiver is called a channel.

[0093] Multipath is a propagation phenomenon that causes a radio signal to take two or more paths to reach a receiver. Multipath can be caused by atmospheric ducting, ionospheric reflection, refraction, and reflection from water and land objects.

[0094] Since these multiple copies of the transmitted signal travel different distances (i.e., each path travels a different distance), the receiver will receive these copies at different times. The time difference between the arrival of the first path component and the last path component of the signal is called the maximum delay spread (MDS).

[0095] 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 superposition of the signals in time. As MDS increases, the quality of the received signal degrades and the transmitted signal cannot be properly demodulated, ultimately resulting in a failure to achieve communication.

[0096] On the other hand, in an actual link, when the baseband shaped pulse (or filter) and the RF filter are non-Nyquist pulses, these shaped pulses and filters will also cause the received signal to have a time delay expansion.

[0097] 2. Orthogonal frequency division multiplexing.

[0098] Figure 1Figure 1 is a schematic diagram of the OFDM system framework. Through serial to parallel conversion (s-to-p), M continuous 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 of 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 .

[0099] like Figure 2 As shown in Figure 1, the next important operation of generating OFDM signals is to insert a guard field at the beginning of each OFDM symbol to eliminate the 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. The specific implementation is to copy X 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 are valid data X k And cyclic prefix (i.e. redundant data), the time domain OFDM signal is obtained:

[0100]

[0101] Among them, [x k [NG],…,x k [N-1]] T Indicates CP.

[0102] 3. CP interception point.

[0103] 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.

[0104] 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 Td . Define T s is the sampling interval, that is, 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.

[0105] 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 can be converted into a frequency domain point multiplication through Fast Fourier Transform (FFT), and then the frequency domain single tap equalization can be used to complete the channel equalization with low complexity.

[0106] like Figure 3 As shown in the figure, there may be timing synchronization errors in the actual link. In order to minimize the negative impact of ISI in the presence of timing errors, the receiver often moves the FFT window position forward. The amount of forward movement 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 In addition, if the receive (RX) FFT window advance exceeds the CP length, the symbol will also be affected by ISI and ICI. For example, the corresponding signal of the last path cannot fall completely within the RX FFT window.

[0107] In the present 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.

[0108] 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.

[0109] 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 =NTs =1 / Δf, Δf is the subcarrier spacing. u The physical meaning is effective data X k duration.

[0110] 4. Orthogonal frequency division multiplexing of discrete Fourier transform spread spectrum.

[0111] Discrete Fourier Transform spreading OFDM (DFT-s-OFDM) defines a data block 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 M-point DFT operation. Through this operation, the DFT-s-OFDM signal has the characteristics of a single carrier, and has a peak-to-average power ratio (PAPR) that is much lower than that of multi-carrier signals such as OFDM. Therefore, under the same power amplifier, DFT-s-OFDM can provide greater output power and higher power amplifier efficiency, thereby achieving the purpose of improving coverage and reducing energy consumption. The coverage and power consumption advantages of DFT-s-OFDM are particularly obvious on the terminal device side. Therefore, in the existing versions of the long term evolution plan (LTE) and the new radio (NR), DFT-s-OFDM is used for uplink transmission.

[0112] 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 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.

[0113] 5. Time domain linear convolution single carrier modulation.

[0114] like Figure 4 As shown in FIG. 1 , a single carrier (SC) is linearly convolved in the time domain and then filtered to generate a signal x. The filtering process includes two steps: upsampling and filtering (i.e., linear convolution of the upsampled signal and the shaped pulse).

[0115] The data sequence 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 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.

[0116] 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.

[0117] 6. Single carrier - frequency domain equalization.

[0118] like Figure 5 As shown, 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 s with a length of M through a 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).

[0119] Due to CP, the linear convolution of the multipath channel is converted into a circular convolution, and then the receiver can use low-complexity single-tap frequency-domain channel equalization.

[0120] 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 The CP of the sampled values, where P up Represents the upsampling factor. represents the floor operator, and represents the ceiling operator. That is, or It can be understood as equal to G.

[0121] 7. CP length in NR protocol.

[0122] Currently, the length of CP is described in the 3GPP related protocols as in Indicates the index 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 in the protocol as The formula is expressed as:

[0123]

[0124]

[0125] Among them, κ = 64. It can be seen that NR supports two CP lengths, normal CP (CP) and extended CP (ECP). Among them, the overhead of CP is about 144 / (2048+144) = 6.6%, while the overhead of ECP is about 512 / (512+2048) = 20%. Therefore, the overhead of ECP is much higher than that of CP. In addition, NR currently stipulates that CP or ECP can be used only when μ = 2, that is, the subcarrier spacing is 60kHz, and CP is used when μ has other values.

[0126] At the sampling interval T s In certain cases, the application may use the number of sampling points included in the time length to describe the time length.

[0127] 8. MCS (modulation and coding scheme) and EVM (Error Vector Magnitude).

[0128] 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, the lower the spectrum efficiency, but the stronger the ability to resist interference (such as ISI, ICI).

[0129] The error vector magnitude (EVM) of a QAM / PSK modulated signal is usually used to measure the signal quality. EVM is defined as the ratio of the magnitude of the error vector to the magnitude of the reference signal, sometimes expressed as a percentage. The EVM calculation formula is as follows:

[0130]

[0131] 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.

[0132] 9. Base station signaling.

[0133] 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.

[0134] Radio Resource Control (RRC): Radio resource management, control and scheduling are performed through certain strategies and means. Under the premise of meeting the quality of service requirements, limited wireless network resources are fully utilized as much as possible to ensure that the planned coverage area is reached and the service capacity and resource utilization are improved as much as possible.

[0135] Media Access Control (MAC): Located between the RRC layer and the physical layer, it is mainly responsible for controlling the transmission of the physical layer and other functions.

[0136] 10. Demodulation reference signal (DMRS).

[0137] like Figure 6 As shown, 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 receiving end first estimates the channel at the reference signal, and then obtains the channel at the data symbol by interpolating in the time domain, and then demodulates the data.

[0138] 11. Self-contained time slot.

[0139] Usually, in the time division duplexing (TDD) mode, uplink transmission and downlink transmission are distinguished by time slots. The uplink time slot (U slot) is used entirely for uplink transmission, while the downlink time slot (D slot) is used entirely for downlink transmission. Self-contained time slots (hereinafter referred to as S slots or S slots) support both uplink and downlink transmission in one time slot. Through time division multiplexing, uplink (UL) transmission and downlink (DL) transmission are located on different OFDM symbols in the same time slot.

[0140] like Figure 7 As shown in the figure, in the S time slot, both the base station and the user equipment (UE) need to switch between uplink and downlink transmission. The guard period (GP) is used to ensure that the uplink and downlink transmission can still work normally after the switch. No signal is sent or received in the GP. The GP is generally an integer multiple of the OFDM symbol time length. Figure 8 The S time slot includes 6 downlink symbols (DL symbols), 4 protection symbols (GP symbols), and 4 uplink symbols (UL symbols).

[0141] like Fig. 9As shown in the figure, GP only exists in the downlink to uplink switching. From the perspective of the base station, the round trip time (RTD) from DL to UL cannot be avoided, and there is no need to wait from UL to DL. The situation from the perspective of the terminal is just the opposite. The round trip time (RTD) from UL to DL cannot be avoided, and there is no need to wait from DL to UL.

[0142] 12. Timing advance (TA).

[0143] like Fig.10 As shown in the figure, since the distances between different UEs and the base station in a cell are different, when timing advance (TA) is not used, the propagation delays of the uplink signals sent by UEs at different locations in the cell to reach the base station are different, causing the uplink signals of each UE to be not aligned in time when they arrive at the base station. After using TA, the signals sent by UEs at different locations in the cell are aligned in time when they arrive at the base station, so that the base station can process all UEs in the same cell at one time. This is the reason for introducing TA.

[0144] Under the LTE protocol or NR protocol, the timing advance TA = 2*t prop +t offset , where t prop represents the transmission delay, and t offset It is related to the TDD base station transmission and reception switching delay. The TA informs the UE through the timing advance command (TA command, TAC).

[0145] 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.

[0146] In a DMRS symbol CP extension scheme, as shown in FIG. 11(a) and FIG. 11(b), the end signal of the symbol before the demodulation reference signal DMRS (such as the R22 part of the symbol before the DMRS symbol in FIG. 11(a)) and the signal in the DMRS located at and before the CP interception point (such as the R22 part of the DMRS symbol in FIG. 11(a)) are made the same. At this time, the equivalent CP length possessed by the DMRS is equal to the length of the original CP plus the length of R22. That is, R22 serves as a supplementary CP (SCP). It should be understood that the CP can also be extended backward, and the supplementary CP is the same as the target field in the symbol after the DMRS, and the starting point of the target field is the starting point of the symbol after the DMRS, such as the R21 part in FIG. 11(b). At this time, the equivalent CP length possessed by the DMRS is equal to the length of the CP plus the length of R21, that is, R21 is CS. Backward extension of the CP requires the RX FFT window position to be offset backward, and the offset is equal to the length of R21.

[0147] This solution is applicable to the case where the symbols before or after DMRS are modulated using DFT-s-OFDM or single carrier modulation. Here, it is assumed that DFT-s-OFDM modulation and CP forward extension are used. Fig.12 As shown, it is assumed that the DMRS symbol corresponds to DFT input data block 2. Component 2 in data block 2 is modulated by DFT-s-OFDM to generate R22 in the DMRS symbol. Fig.12 As shown, component 2 is copied to the end of component 1 to form data block 1. Data block 1 is modulated by DFT-s-OFDM to generate symbols before DMRS.

[0148] In the existing demodulation reference signal cyclic prefix extension scheme, the R22 (R21) part in the DMRS symbol is approximately the same as the R22 (R21) part of the previous (next) symbol. At high signal to noise ratio (SNR), the approximation error may impair the channel estimation performance.

[0149] The present application can be applied to various communication systems, such as: fifth generation (5th generation, 5G) system or new wireless (New radio, NR), satellite communication system, long term evolution (long term evolution, LTE) system, etc. The present application can also be applied to future communication systems, such as the 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.

[0150] Fig.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 Fig.13 The network devices 111, 112 and 113 are shown. The wireless communication system may also include at least one terminal device, such as Fig.13 The terminal devices 121, 122, 123, 124, 125, 126, and 127 are shown. The network devices and the terminal devices can communicate with each other, such as Fig.13 As shown in the multi-site transmission, for example, the network device 112 can communicate with the terminal device 121, the terminal device 122, and the terminal device 123; Fig.13 The enhanced mobile broadband (eMBB) transmission shown in FIG. 1 is a transmission method for transmitting the mobile broadband signal to the mobile terminal 124. For example, the network device 112 and the network device 113 can communicate with the terminal device 124. The network devices can also communicate with each other, such as Fig.13 The backhaul shown, such as network device 111 can communicate with network device 112 and network device 113. Terminal devices can also communicate with each other, such as Fig.13 As shown in the D2D transmission, terminal device 122 can communicate with terminal device 125.

[0151] It should be understood that the above Fig.13It is an exemplary description, and the present application is not limited thereto. The present application can be applicable 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 can also be 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.

[0152] The terminal equipment in the communication system can be called user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal equipment can be a device that provides voice / data connectivity to the user, 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 (MID), 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 functions, 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 (public land mobile The present application embodiment does not limit this. In vehicle networking communication, the communication terminal loaded on the vehicle is a terminal device, and the road side unit (RSU) can also be regarded as a terminal device. The communication terminal loaded on the drone can also be regarded as a terminal device.

[0153] The terminal device can also be a wearable device. Wearable devices can also be called wearable smart devices. They are a general term for wearable devices that use wearable technology to intelligently design daily wearables and develop wearable devices, such as glasses, gloves, watches, clothing and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothes 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 full-featured, large-sized, and independent of smartphones to achieve complete or partial functions, such as smart watches or smart glasses, as well as those that only 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.

[0154] 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.

[0155] A network device in a communication system may be a device that can communicate with a terminal device. The network device may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device may refer to a radio access network (RAN) node (or device) that connects the 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, transmission point (TRP), transmission 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, base band 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. The base station may also refer to a communication module, modem or chip used to be set in the aforementioned equipment or device. The base station may also be a mobile switching center and a device that performs the base station function in D2D, V2X, and M2M communications, a network-side device in a 6G network, or a device that performs the base station function in a future communication system. The base station may support networks with the same or different access technologies. The present invention does not limit the specific technology and specific device form used by the network equipment.

[0156] 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.

[0157] The network equipment and terminal equipment can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on airplanes, balloons and satellites in the air. The present invention does not limit the scenarios in which the network equipment and terminal equipment are located.

[0158] It is understandable that in the embodiments of the present application, the execution subject may execute some or all of the steps in the embodiments of the present application, and these steps or operations are only examples. The embodiments of the present application may also execute other operations or variations of various operations. In addition, the various steps may be executed in different orders 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 executed.

[0159] 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, and other names may be used in the specific implementation, and the embodiments of the present application do not specifically limit this.

[0160] like Fig.14 As shown, an embodiment of the present application provides a method for extending a demodulation reference signal DMRS cyclic prefix CP, the method comprising: generating a demodulation reference signal DMRS symbol, the DMRS symbol comprising an extension field, the extension field comprising a supplementary cyclic prefix SCP or a cyclic suffix CS; sending a first signal, the first signal comprising a DMRS symbol.

[0161] Specifically, the method may 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.

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

[0163] 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.

[0164] 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 yes, it can also indicate whether the extended field is SCP or CS and the length of the extended field.

[0165] In the embodiment of the present application, the forward extension of the DMRS and the extension amount may be notified in advance by the network device to the user device. Specifically, the network device may send control information to the user device, the control information being used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0166] In an embodiment of the present application, before the user equipment generates the first signal, the user equipment also receives 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.

[0167] In addition, the control information may include first control information and second control information, the first control information being carried by DCI and used to indicate whether an extended field is included, and if the extended field is included, the length of the extended field is also indicated; the second control information is carried by MAC-CE signaling or RRC signaling, and the second control information includes a set of candidate lengths of multiple extended fields, and 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 an extended field is included, or if it is determined that the extended field is included, it may also indicate the extended length, that is, the length of the extended field.

[0168] In an embodiment of the present application, when specifically indicating the length of the extended field, the control information may directly indicate the length of the extended field. In addition, it may also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, 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 extended field length and the candidate length information in the first control information.

[0169] By adding an extension field in the DMRS symbol, the CP lossless extension of the DMRS symbol is achieved.

[0170] The following is an example of several embodiments:

[0171] 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:

[0172] Embodiment 1:

[0173] like Fig.15 As shown, a method for extending a cyclic prefix CP of a demodulation reference signal DMRS provided by the present application, in which 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 at a physical uplink shared channel PUSCH, the method includes:

[0174] The user equipment sends a first signal to the network equipment, the first signal including a demodulation reference signal DMRS, the DMRS including a CP and a supplementary cyclic prefix SCP. Fig.15 As shown, 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, and the supplementary cyclic prefix SCP, CP and data block of the DMRS are arranged in sequence. The equivalent CP owned by the DMRS includes the original CP and SCP.

[0175] In this embodiment, Fig.16 As shown, 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.

[0176] In this embodiment, the forward extension of the DMRS and the extension amount (i.e., the length of the SCP) may be notified in advance by the network device to the user device, and the 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 device, and the control information is used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after the CP extension, the control information may also indicate the specific extension length.

[0177] For example, in this embodiment, before the user equipment generates the first signal, the user equipment also receives 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 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 SCP.

[0178] In addition, the control information may include first control information and second control information, the first control information is carried by DCI and is used to indicate whether to send SCP or the length of SCP; the second control information is carried by MAC-CE signaling or RRC signaling, and the second control information includes a candidate length set of multiple SCPs, and the length of SCP indicated by the first control information is included in the candidate length set. That is, the first control information can indicate whether to include SCP or, if it is determined that SCP is included, it can also indicate the extended length, that is, the length of SCP.

[0179] 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 one by one. The user equipment may determine the specific length of the extended field through the SCP length and the candidate length information in the first control information.

[0180] 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 later.

[0181] 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,

[0182] TA=2*t prop +t offset +T SCP ;

[0183] Among them, T SCP is the length of SCP. TA can inform UE through TAC.

[0184] In this embodiment, the DMRS overlaps with the previous symbol in the time domain, and the overlapping portion is the length of the SCP.

[0185] In this embodiment, the length of the supplementary cyclic prefix SCP may be affected by the following factors:

[0186] Factor 1: The difference between the maximum channel delay spread MDS and CP. To ensure lossless DMRS channel estimation performance, the length of SCP plus CP must be no less than MDS.

[0187] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of SCP plus CP must not be less than MDS. In an actual noisy environment, the length of SCP plus CP can also be lower than MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of SCP can be lower than the difference between the lengths of MDS and CP. For example, when MDS is 4 times the length of CP, the length of SCP can be twice or even 1 times the length of 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.

[0188] Factor 3: Interference of SCP on the previous symbol. From the perspective of the network device, the DMRS symbol overlaps with the second symbol, and the overlap range is equal to the length of SCP, such as Fig.16 As shown in the dotted box marked as "SCP" in the figure. 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 in the channel estimation performance of the DMRS symbol and the deterioration in the performance of the DMRS symbol for the second symbol. If the second symbol has weak anti-ISI capability or the performance is required not to be affected by ISI, the length of the SCP is limited. If the second symbol has a redundant signal at the end, such as a zero signal as a guard band to reduce the impact of the SCP on the second symbol, the length of the SCP cannot exceed the length of the redundant signal.

[0189] 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 does not need to consider its demodulation performance.

[0190] The cost of introducing redundant signals is to reduce spectrum efficiency, because redundant signals do not transmit valid information. Or equivalently, under spectrum efficiency alignment, the increase in redundant signal overhead is equivalent to an increase in code rate. The demodulation SNR increases with the increase in code rate. The degree of spectrum efficiency reduction or code rate increase is related to the payload size of other users' PUSCH. The larger the payload, the smaller the degree of spectrum efficiency reduction. Assume that the redundant signal corresponds to 10 fewer modulation symbols transmitted. If the PUSCH of other users has a payload of 1000 modulation symbols when there is no redundant signal, the redundant signal causes a 1% loss in frequency domain efficiency. If the PUSCH of other users has a payload of 100 modulation symbols when there is no redundant signal, the redundant signal causes 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 the payload can also be the number of information bits carried by the PUSCH.

[0191] In this embodiment, if Fig.16 As shown, 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.

[0192] In this embodiment, by adding SCP to the DMRS symbol, lossless extension of the CP of the DMRS symbol is achieved.

[0193] Embodiment 2:

[0194] like Fig.17 As shown, a method for extending a cyclic prefix CP of a demodulation reference signal DMRS provided by the present application, in which the demodulation reference signal DMRS is located at the head of a first signal, and the first signal is located at a physical uplink shared channel PUSCH, the method includes:

[0195] The user equipment sends a first signal to the network equipment, the first signal including a demodulation reference signal DMRS, the DMRS including a normal cyclic prefix CP and a supplementary cyclic prefix SCP. Fig.17 As shown, 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, such as Fig.17 As shown, the normal cyclic prefix CP of the DMRS, the supplementary cyclic prefix SCP and the data block of the DMRS are arranged in sequence.

[0196] In this embodiment, the excess part of the DMRS symbol is located behind the DMRS symbol, so it is called CP backward extension.

[0197] In this embodiment, different from 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).

[0198] It can also be understood that, relative to the DMRS in the first embodiment, the DMRS symbol is shifted backward as a whole, and the amount of the shift is equal to the length of the SCP.

[0199] 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.

[0200] 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.

[0201] 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 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.

[0202] In this embodiment, TA does not need to be adjusted.

[0203] In this embodiment, the DMRS CP extension and the extension amount (i.e., the length of the SCP) may be notified in advance by the network device to the user equipment. Specifically, the network device may send control information to the user equipment, the control information being used to indicate whether the user equipment performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0204] In this embodiment, before the user equipment generates the first signal, the user equipment also receives 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 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 SCP.

[0205] In addition, the control information may include first control information and second control information, the first control information being carried by DCI and used to indicate whether the SCP is included, and in the case of including the extension field, also indicating the length of the SCP; the second control information being carried by MAC-CE signaling or RRC signaling, and the second control information including a candidate length set of multiple SCPs, the length of the SCP indicated by the first control information being included in the candidate length set. That is, the first control information may indicate whether the SCP is included, or in the case of determining that the SCP is included, may also indicate the extended length, that is, the length of the SCP.

[0206] In this embodiment, 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 one by one. The user equipment may determine the specific length of the SCP through the SCP length and the candidate length information in the first control information.

[0207] In this embodiment, the length of the supplementary cyclic prefix SCP may be affected by the following factors:

[0208] Factor 1: The difference between the maximum channel delay spread MDS and CP. To ensure lossless DMRS channel estimation performance, the length of SCP plus CP must be no less than MDS.

[0209] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of SCP plus CP must not be less than MDS. In an actual noisy environment, the length of SCP plus CP can also be lower than MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of SCP can be lower than the difference between the lengths of MDS and CP. For example, when MDS is 4 times the length of CP, the length of SCP can be twice or even 1 times the length of 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.

[0210] Factor 4: Interference level of DMRS on the third symbol. A DMRS symbol with a length of MDS-CP+SCP falls within the RX FFT window of the third symbol (e.g. Fig.17The dotted box in the figure causes ISI. The longer the SCP, the greater the impact of ISI on the third symbol. Considering that the ability of the third symbol to resist ISI is limited, the length of the 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 the first embodiment, the degree of lack of CP is more serious and the ICI suffered is more serious. 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.

[0211] Embodiment three:

[0212] like Fig.18 As shown, a method for extending a cyclic prefix CP of a demodulation reference signal DMRS provided by the present application, in which the demodulation reference signal DMRS is located at the head of a first signal, and the first signal is located at a physical uplink shared channel PUSCH, the method includes:

[0213] The user equipment sends a first signal to the network equipment, the first signal including a demodulation reference signal DMRS, the DMRS including a regular cyclic prefix CP and a cyclic suffix (CS). Fig.18 As shown, in the case where the extended field is CS, 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 of the end position of the CP of the DMRS symbol, and the normal cyclic prefix CP of the DMRS, the data block of the DMRS and the cyclic suffix CS are arranged in sequence. The equivalent CP length of the DMRS is the original CP plus the CS.

[0214] In this embodiment, if Fig.19 As shown, the header signal of the third symbol is replaced by 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 next symbol of the DMRS symbol in the first signal.

[0215] 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 keep the PUSCH length unchanged. From the perspective of the network device, the received DMRS will not overlap with the second symbol, such as Fig.19 In addition, DMRS only causes ISI to the third symbol. The RX FFT window corresponding to the DMRS symbol is shifted backward by the length of CS relative to the TX IFFT window.

[0216] In this embodiment, the DMRS CP extension and the extension amount may be notified in advance by the network device to the user device. Specifically, the network device may send control information to the user device, the control information being used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0217] In this embodiment, before the user equipment generates the first signal, the user equipment also receives 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 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.

[0218] In addition, the control information may include first control information and second control information, the first control information is carried by DCI, and is used to indicate whether CS is included, and when the extension field is included, it also indicates the length of CS; the second control information is carried by MAC-CE signaling or RRC signaling, and the second control information includes a set of candidate lengths of multiple CSs, and the length of CS indicated by the first control information is included in the set of candidate lengths. That is, the first control information can indicate whether CS is included or, when it is determined that CS is included, it can also indicate the extended length, that is, the length of CS.

[0219] In this embodiment, when specifically indicating the length of the CS, the control information may directly indicate the length of the CS. In addition, it may also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the CS, 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 one-to-one to a length identifier such as a symbol or a sequence number. The user equipment may determine the specific length of the CS through the CS length and the candidate length information in the first control information.

[0220] In this embodiment, factors affecting the design of CS length include:

[0221] Factor 1: The difference between the length of the maximum channel delay spread MDS and CP. To ensure lossless DMRS channel estimation performance, the length of CS plus CP must be no less than MDS.

[0222] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of CS plus CP must not be less than MDS. In an actual noisy environment, the length of CS plus CP may also be lower than MDS. For example, in a strong noise environment or with low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of CS can be lower than the difference in length between MDS and CP. For example, when MDS is 4 times the length of CP, the length of CS can be twice or even 1 times the length of 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.

[0223] Factor 4: 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 lack of CP is more serious, and the ICI suffered is more serious. 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.

[0224] Embodiment 4:

[0225] like Fig. 20 As shown, a method for extending a cyclic prefix CP of a demodulation reference signal DMRS provided by the present application, in which the demodulation reference signal DMRS is located in the middle or tail of a first signal, and the first signal is located in a physical uplink shared channel PUSCH, the method includes:

[0226] The user equipment sends a first signal to the network equipment, the first signal including a demodulation reference signal DMRS, the DMRS including a normal cyclic prefix CP and a supplementary cyclic prefix SCP. Fig. 20 As shown, 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, such as Fig. 20 As shown, the supplementary cyclic prefix SCP, the normal cyclic prefix CP of the DMRS and the data block of the DMRS are arranged in sequence.

[0227] The demodulation reference signal in this embodiment adopts a new forward extension method. The tail signal of the previous symbol of the DMRS symbol (called the fourth symbol) is a redundant signal, such as a zero signal. Fig. 20 As shown in Figure 1, the SCP is placed at the redundant signal location by using a hole. In this solution, the TA does not need to be adjusted.

[0228] In this embodiment, the tail field of the fourth symbol is replaced by SCP, and the cutoff point of the tail field of the fourth symbol is the cutoff point of the fourth symbol.

[0229] In this embodiment, the DMRS CP extension and the extension amount may be notified in advance by the network device to the user device. Specifically, the network device may send control information to the user device, the control information being used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0230] In this embodiment, before the user equipment generates the first signal, the user equipment also receives 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 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 SCP.

[0231] In addition, the control information may include first control information and second control information, the first control information being carried by DCI and used to indicate whether the SCP is included, and in the case of including the extension field, also indicating the length of the SCP; the second control information being carried by MAC-CE signaling or RRC signaling, and the second control information including a candidate length set of multiple SCPs, the length of the SCP indicated by the first control information being included in the candidate length set. That is, the first control information may indicate whether the SCP is included, or in the case of determining that the SCP is included, may also indicate the extended length, that is, the length of the SCP.

[0232] In this embodiment, 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 one by one. The user equipment may determine the specific length of the SCP through the SCP length and the candidate length information in the first control information.

[0233] Regarding the previous symbol, its CP can be added after adding SCP, so as to obtain Fig. 20 The fourth symbol shown.

[0234] In this embodiment, factors affecting the design of SCP length include:

[0235] Factor 1: The difference between the maximum channel delay spread MDS and CP. To ensure lossless DMRS channel estimation performance, the length of SCP plus CP must be no less than MDS.

[0236] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of SCP plus CP must not be less than MDS. In an actual noisy environment, the length of SCP plus CP can also be lower than MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of SCP can be lower than the difference between the lengths of MDS and CP. For example, when MDS is 4 times the length of CP, the length of SCP can be twice or even 1 times the length of 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.

[0237] Factor 3: Interference of SCP on the fourth symbol. From the perspective of network equipment, SCP will fall into the RX FFT window of the fourth symbol, resulting in ISI, affecting 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 DMRS symbols and the deterioration in the performance of DMRS symbols on the fourth symbol. If the fourth symbol has weak anti-ISI capability or requires that the performance is not affected by ISI, the length of 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 SCP cannot exceed the length of the redundant signal.

[0238] 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.

[0239] Embodiment five:

[0240] like Fig.21 As shown, a method for extending a demodulation reference signal DMRS cyclic prefix CP provided by the present application includes:

[0241] 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).

[0242] The user equipment sends a first signal to the network equipment, the first signal including a demodulation reference signal DMRS, the DMRS including a normal cyclic prefix CP and a supplementary cyclic prefix SCP. Fig.15 As shown, 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, such as Fig.21 As shown, the supplementary cyclic prefix SCP, the normal cyclic prefix CP of the DMRS and the data block of the DMRS are arranged in sequence.

[0243] In this embodiment, Fig.21 As shown, in this embodiment, the SCP is located in the GP before the DMRS symbol.

[0244] 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.

[0245] 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,

[0246] TA=2*t prop +t offset +T SCP ;

[0247] The way for the UE to determine whether the symbol before the DMRS symbol is a GP is as follows: First, the UE can know the tdd-UL-DL-Configuration through the broadcast message, so that it can know 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 determine that the symbol before the DMRS symbol is a GP in other ways. 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.

[0248] In this embodiment, factors affecting the design of SCP length include:

[0249] Factor 1: The difference between the maximum channel delay spread MDS and CP. To ensure lossless DMRS channel estimation performance, the length of SCP plus CP must be no less than MDS.

[0250] Factor 2: PUSCH operates at a high signal-to-noise ratio (SNR). Based on the analysis of factor 1, the length of SCP plus CP must not be less than MDS. In an actual noisy environment, the length of SCP plus CP can also be lower than MDS. For example, in a strong noise environment or with a low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of SCP can be lower than the difference between the lengths of MDS and CP. For example, when MDS is 4 times the length of CP, the length of SCP can be twice or even 1 times the length of 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.

[0251] 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 Contains some other delays including UE transmit / receive conversion delay.

[0252] In the embodiments of the present application, embodiments 6 to 8 are cases where a network device sends a DMRS symbol to a user equipment, which are described in detail below:

[0253] Embodiment six:

[0254] The present application provides a method for extending a cyclic prefix CP of a demodulation reference signal DMRS, where the demodulation reference signal DMRS is located at the head or middle of a first signal, and the first signal is located at a physical downlink shared channel PDSCH, the method comprising:

[0255] The network device sends a first signal to the 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).

[0256] In this embodiment, when the DMRS symbol is located at the head of the PDSCH, the network device can extend the CP of the DMRS symbol in any of the methods in the second embodiment or the third embodiment, and the details are not repeated here.

[0257] In this embodiment, when the DMRS symbol is located in the middle of the PDSCH, the network device can extend the CP of the DMRS symbol in any of the methods in Embodiment 2, Embodiment 3 or Embodiment 4, and the details are not repeated here.

[0258] In this embodiment, the network device may instruct the UE on the extension method and extension amount.

[0259] In this embodiment, the DMRS CP extension and the extension amount may be notified in advance by the network device to the user device. Specifically, the network device may send control information to the user device, the control information being used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0260] In this embodiment, before the user equipment generates the first signal, the user equipment also receives 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.

[0261] In addition, the control information may include first control information and second control information, the first control information being carried by DCI and used to indicate whether an extended field is included, and if the extended field is included, the length of the extended field is also indicated; the second control information is carried by MAC-CE signaling or RRC signaling, and the second control information includes a set of candidate lengths of multiple extended fields, and 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 an extended field is included, or if it is determined that the extended field is included, it may also indicate the extended length, that is, the length of the extended field.

[0262] In this embodiment, when specifically indicating the length of the extended field, the control information may directly indicate the length of the extended field. In addition, it may also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, 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 one-to-one to a length identifier such as a symbol or a sequence number. The user equipment may determine the specific length of the extended field through the extended field length and the candidate length information in the first control information.

[0263] Embodiment seven:

[0264] like Fig. 22 As shown, the present application provides a method for extending a cyclic prefix CP of a demodulation reference signal DMRS, where the demodulation reference signal DMRS is located at the tail of a first signal, and the first signal is located at a physical downlink shared channel PDSCH, the method comprising:

[0265] The network device sends a first signal to the 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.

[0266] The PDSCH is located in the S time slot, and the next symbol (ie, the third symbol) of the DMRS is a GP, and the DMRS CP is extended in the manner of the second embodiment or the third embodiment.

[0267] From the perspective of network equipment, part of the DMRS symbol is located within the GP, such as Fig. 22 The network device may instruct the UE on the extension method and extension amount.

[0268] In this embodiment, the DMRS CP extension and the extension amount may be notified in advance by the network device to the user device. Specifically, the network device may send control information to the user device, the control information being used to indicate whether the user device performs CP extension on the DMRS symbol; in the case of determining to send the DMRS symbol after CP extension, the control information may also indicate the specific extension length.

[0269] In this embodiment, before the user equipment generates the first signal, the user equipment also receives 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.

[0270] In addition, the control information may include first control information and second control information, the first control information being carried by DCI and used to indicate whether an extended field is included, and if the extended field is included, the length of the extended field is also indicated; the second control information is carried by MAC-CE signaling or RRC signaling, and the second control information includes a set of candidate lengths of multiple extended fields, and 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 an extended field is included, or if it is determined that the extended field is included, it may also indicate the extended length, that is, the length of the extended field.

[0271] In this embodiment, when specifically indicating the length of the extended field, the control information may directly indicate the length of the extended field. In addition, it may also be indicated in other ways. For example, the above-mentioned first control information indicates the length of the extended field, 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 one-to-one to a length identifier such as a symbol or a sequence number. The user equipment may determine the specific length of the extended field through the extended field length and the candidate length information in the first control information.

[0272] In this embodiment, factors affecting the design of extending the field length include:

[0273] Factor 1: The difference between the length of the maximum channel delay spread MDS and CP. 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.

[0274] 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 a low SNR, the main factor restricting the accuracy of channel estimation is noise. At this time, the length of the extended field can be lower than the length difference between the MDS and the CP. For example, when the MDS is 4 times the length of the CP, the length of the extended field can be twice or even 1 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.

[0275] 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 not to 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 Contains some other delays including UE transmit / receive conversion delay.

[0276] Embodiment eight:

[0277] The present application provides a method for extending a cyclic prefix CP of a demodulation reference signal DMRS, where the demodulation reference signal DMRS is located at a head of a first signal, and the first signal is located at a physical downlink shared channel PDSCH, the method comprising:

[0278] The network device sends a first signal to the 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.

[0279] 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 in the manner of the fourth embodiment.

[0280] Compared with the sixth embodiment, 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.

[0281] 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 in the manner shown in Example 4.

[0282] For the physical downlink shared channel PDSCH, the DRMS ​​symbol can be extended forward or backward.

[0283] In an embodiment of the present application, when a DMRS symbol can be extended in multiple ways, a network device or a user device can select a CP extension method according to the importance level of the previous symbol and the next symbol of the DMRS symbol and the multi-user DMRS symbol multiplexing method.

[0284] In the embodiment of the present application, the higher the importance level of the symbol, the higher the level of the symbol is required to be free from interference or to be subject to very little interference in order to ensure that the demodulation or parameter estimation performance based on the symbol is not affected. 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), high-reliability symbols, etc.

[0285] 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.

[0286] For low-level symbols, such as ordinary data symbols, and the MCS is lower than a certain threshold or the EVM is higher than a certain threshold, the symbol can withstand certain interference.

[0287] The extension direction of DMRS symbols should be towards the direction of symbols with strong anti-interference ability. Taking PUSCH DMRS symbols as an example, assuming that the next symbol of DMRS symbols has strong anti-ISI ability, the backward extension scheme can be adopted.

[0288] In addition, the DMRS symbol extension direction is also related to the multi-user DMRS symbol multiplexing mode. If the DMRSs belonging to different UEs are frequency-division multiplexed and occupy the same time resources, in order to avoid deteriorating the channel estimation performance of the DMRSs of other UEs, the DMRS CP is extended in the forward direction.

[0289] In the embodiments of the present application, for embodiments that require the 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.

[0290] 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.

[0291] 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 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 function division. There may be other division methods in actual implementation.

[0292] In the case of dividing each functional module into corresponding functional modules, Fig.23 A possible structural diagram of the user equipment 2300 involved in the above embodiment is shown. Fig.23 As shown, the user equipment 2300 includes:

[0293] The receiving module 2301 is used 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.

[0294] 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.

[0295] The sending module 2303 is used to send a first signal to the network device, where the first signal includes a DMRS symbol.

[0296] The various modules of the above-mentioned user equipment 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, which will not be repeated here.

[0297] The embodiment of the present application provides another user equipment 2400. In the embodiment of the present application, the user equipment 2400 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 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 function division. There may be other division methods in actual implementation.

[0298] In the case of dividing each functional module into corresponding functional modules, Fig.24 A possible structural diagram of the user equipment 2400 involved in the above embodiment is shown. Fig.24As shown, the user equipment 2400 includes:

[0299] The first receiving module 2401 is used 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.

[0300] 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.

[0301] The various modules of the above-mentioned user equipment 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, which will not be repeated here.

[0302] 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 corresponding to each function, or two or more functions can be integrated into one processing module. The above 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 function division. There may be other division methods in actual implementation.

[0303] In the case of dividing each functional module into corresponding functional modules, Fig.25 A possible structural diagram of the network device 2500 involved in the above embodiment is shown. Fig.25 As shown, the network device 2500 includes:

[0304] A sending module 2501 is used 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 is SCP or CS and the length of the extension field;

[0305] The receiving module 2502 is configured to receive 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.

[0306] 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.

[0307] 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 corresponding to each function, or two or more functions can be integrated into one processing module. The above 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 function division. There may be other division methods in actual implementation.

[0308] In the case of dividing each functional module into corresponding functional modules, Fig.26 FIG. 2 is a schematic diagram showing a possible structure of the network device 2600 involved in the above embodiment. Fig.26 As shown, the network device 2600 includes:

[0309] 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;

[0310] The first sending module 2602 is used 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 is SCP or CS and the length of the extension field;

[0311] The second sending module 2603 is used 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 SCP or CS.

[0312] 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.

[0313] Fig. 27 It is a schematic diagram of a user equipment structure provided in an embodiment of the present application. The user equipment 2700 may include one or more central processing units (CPU) 2701 and a memory 2705. The memory 2705 stores one or more application programs or data.

[0314] The memory 2705 may be a volatile storage or a persistent storage. The program stored in the memory 2705 may include one or more modules, each of which may include a series of instruction operations on the user device. Furthermore, the central processor 2701 may be configured to communicate with the memory 2705 and execute a series of instruction operations in the memory 2705 on the user device 2700.

[0315] The central processor 2701 is used to execute the computer program in the memory 2705, so that the user equipment 2700 is used to execute: the user equipment generates a demodulation reference signal DMRS symbol, the DMRS symbol includes an extension field, and the extension field includes a supplementary cyclic prefix SCP or a cyclic suffix CS; sends a first signal, and the first signal includes a DMRS symbol. Or the user equipment 2700 is used to execute: the user equipment receives a first signal, 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.

[0316] 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 ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0317] The user equipment 2700 can execute the operations executed by the user equipment in the aforementioned embodiments, and the details are not repeated here.

[0318] Fig.28 It 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 (CPU) 2801 and a memory 2805. The memory 2805 stores one or more application programs or data.

[0319] The memory 2805 may be a volatile storage or a persistent storage. The program stored in the memory 2805 may include one or more modules, each of which may include a series of instruction operations in the network device. Furthermore, the central processor 2801 may be configured to communicate with the memory 2805 and execute a series of instruction operations in the memory 2805 on the network device 2800.

[0320] The central processor 2801 is used to execute the computer program in the memory 2805, so that the network device 2800 is used to execute: the network device sends control information, 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 SCP or CS and the length of the extension field. Or so that the network device 2800 is used to execute: the network device generates a demodulation reference signal DMRS symbol, 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, and the first signal includes a DMRS symbol.

[0321] The 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.

[0322] 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 ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0323] The network device 2800 can execute the operations performed by the network devices in the aforementioned embodiments, and the details will not be repeated here.

[0324] An embodiment of the present application provides a communication system 2900, which 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, and the details are not repeated here.

[0325] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, all or part of the processes (or functions) of the embodiments of the present application are implemented. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. Computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that contains one or more servers that can be integrated with a medium. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)), etc. In the embodiment of the present application, the computer may include the above device.

[0326] 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 changes to the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" 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 cyclic prefix of a demodulation reference signal, It is 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, It is 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, It is characterized in that The extension field is SCP.

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

5. The method according to claim 4, It is 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, It is 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, It is 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, It is 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, It is 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, It is characterized in that The first signal is transmitted through a physical downlink shared channel.

11. The method according to claim 5 or 9, It is 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, It is characterized in that The extension field is CS.

13. The method according to claim 12, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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 cyclic prefix of a demodulation reference signal, It is 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, It is 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 cyclic prefix of a demodulation reference signal, It is 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 cyclic prefix of a demodulation reference signal, It is 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, It is 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 cyclic prefix of a demodulation reference signal, It is 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, It is 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 device, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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, It is 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.

Images