Symbol processing method, communication apparatus, and communication system

Abstract

A symbol processing method, a communication apparatus, and a communication system, which relate to the technical field of communications. The method comprises: a first communication apparatus generating a first time slot, the first time slot comprising a plurality of orthogonal frequency-division multiplexing (OFDM) symbols, the plurality of OFDM symbols comprising a first OFDM symbol and a second OFDM symbol, the first OFDM symbol being the first OFDM symbol among the plurality of OFDM symbols, the first OFDM symbol comprising a first cyclic prefix (CP), the second OFDM symbol comprising a second CP, the length of the first CP being greater than the length of the second CP, the length of the first CP being greater than a first numerical value, and the first numerical value corresponding to a subcarrier spacing; and the first communication apparatus sending the first time slot, and correspondingly, a second communication apparatus receiving the first time slot. By using the embodiments of the present application, signal loss can be reduced, and the demodulation performance can be ensured.

Description

Symbol processing method, communication device and communication system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 23, 2023, with application number 202311585145.8, and priority to the Chinese patent application entitled “Symbol Processing Method, Communication Device and Communication System”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a symbol processing method, a communication device, and a communication system. Background Art

[0003] A cyclic prefix (CP) acts as a guard interval between symbols to mitigate channel multipath. The transmitter copies a portion of the signal at the end of each symbol (i.e., the symbol component) and appends it to the beginning of the symbol to obtain the CP for that symbol, thereby increasing the guard interval.

[0004] For example, in a wireless communication system, a terminal device and a network device can communicate based on orthogonal frequency-division multiplexing (OFDM) symbols. Each OFDM symbol corresponds to a fast Fourier transform (FFT) receiving window, and the receiving end receives the corresponding OFDM symbol within the FFT receiving window. Each OFDM symbol includes a CP and a data symbol. The length of the FFT receiving window corresponding to each OFDM symbol is the length of the data symbol of one OFDM symbol, and the starting position of the FFT receiving window corresponding to each OFDM symbol is determined based on the ending position of the CP.

[0005] However, due to refraction, reflection and other phenomena when the signal is transmitted in the channel, the signal is transmitted to the receiving end through multiple transmission paths. When the arrival delay difference between the two transmission paths of the channel is large, the OFDM symbols on some transmission paths cannot fall completely within the corresponding FFT receiving window, resulting in the loss of part of the signal of the OFDM symbol and reducing the demodulation performance. Summary of the Invention

[0006] The embodiments of the present application provide a symbol processing method, a communication device, and a communication system, which can reduce signal loss and ensure demodulation performance.

[0007] In a first aspect, embodiments of the present application provide a symbol processing method that can be performed by a first communication device. The first communication device herein may refer to the first communication device itself, or to a processor, module, chip, or chip system in the first communication device that implements the method, without limitation. The method includes:

[0008] Generate a first time slot, the first time slot includes multiple orthogonal frequency division multiplexing (OFDM) symbols, the multiple OFDM symbols include a first OFDM symbol and a second OFDM symbol, the first OFDM symbol is the first OFDM symbol in the multiple OFDM symbols, the first OFDM symbol includes a first cyclic prefix (CP), the second OFDM symbol includes a second CP, the length of the first CP is greater than the length of the second CP, the length of the first CP is greater than a first value, and the first value corresponds to the subcarrier spacing; send the first time slot.

[0009] In an embodiment of the present application, the first value may be the length of the CP specified in an existing protocol. The first value corresponds to the subcarrier spacing, that is, the value of the first value is different under different subcarrier spacings. In an embodiment of the present application, by extending the length of the first CP, that is, copying more signals from the end of the first OFDM symbol to the front of the first OFDM symbol, the first OFDM symbol transmitted on each transmission path can fall within the corresponding FFT receiving window, thereby reducing signal loss and improving demodulation performance.

[0010] With reference to the first aspect, in a possible implementation, the first communication device is a terminal device, and the method further includes:

[0011] First indication information is received, where the first indication information indicates a length of the first CP.

[0012] In combination with the first aspect, in a possible implementation method, the first indication information is carried by any one of the following: downlink control information, radio resource control signaling, media access control (MAC) control element (CE), system information block (SIB), and physical downlink shared channel (PDSCH).

[0013] With reference to the first aspect, in a possible implementation, the first communication device is a network device, and the method further includes:

[0014] The length of the first CP is determined based on a delay spread of a first channel, where the delay spread is a difference between transmission delays of the first time slot in a first transmission path and a second transmission path of the first channel, and the first channel carries the first time slot.

[0015] With reference to the first aspect, in a possible implementation, the first communication apparatus is a terminal device, the first time slot is included in a first subframe, and the method further includes:

[0016] Receive second indication information, the second indication information including at least one of the following: a first timing advance TA, the starting time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the starting time of the first subframe compared to the arrival time of the downlink subframe, and the second difference is the difference between the starting time of the first CP and the starting time of the sixth symbol component in the first OFDM symbol, the ending position of the sixth symbol component is the ending position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP; sending the first time slot includes: sending the first subframe based on the second indication information.

[0017] In the embodiment of the present application, the sixth symbol component can be understood as the CP of the first OFDM symbol before the CP is extended, and the length of the sixth symbol component is equal to the CP length of the first OFDM symbol before the CP is extended. When the CP length of the first OFDM symbol changes, the network device can instruct the terminal device to send the first subframe through the second indication information to ensure uplink timing synchronization between the terminal device and the network device.

[0018] In a second aspect, embodiments of the present application provide a symbol processing method that can be performed by a second communication device. The second communication device here can refer to the second communication device itself, or to a processor, module, chip, or chip system that implements the method in the second communication device, without limitation. The method includes:

[0019] Receive a first time slot, where the first time slot includes multiple orthogonal frequency division multiplexing (OFDM) symbols, the multiple OFDM symbols include a first OFDM symbol and a second OFDM symbol, the first OFDM symbol is the first OFDM symbol among the multiple OFDM symbols, the first OFDM symbol includes a first cyclic prefix (CP), the second OFDM symbol includes a second CP, the length of the first CP is greater than the length of the second CP, the length of the first CP is greater than a first value, and the first value corresponds to the subcarrier spacing; parse the first time slot.

[0020] In conjunction with the second aspect, the second communication device is a network device, the first time slot is included in a first subframe, and the method further includes:

[0021] Send second indication information, the second indication information including at least one of the following: a first timing advance TA, the starting time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the starting time of the first subframe compared to the arrival time of the downlink subframe, the second difference is the difference between the starting time of the first CP and the starting time of the sixth symbol component in the first OFDM symbol, the ending position of the sixth symbol component is the ending position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP.

[0022] In combination with the first aspect or the second aspect, in a possible implementation, the index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of -μ +16β); or, the index of the first OFDM symbol in the first subframe is not equal to 0 or 7*2 μ In the case of -μ wherein the first subframe includes the first time slot, the β corresponds to the maximum number of subcarriers and the maximum subcarrier spacing of the transmission bandwidth, and the μ corresponds to the subcarrier spacing configuration. Exemplarily, the β may be κ, where κ = Ts / Tc = 64.

[0023] In the embodiment of the present application, the first numerical value can be understood as the length of the first CP before extension. Each symbol in the first subframe can correspond to an index, and OFDM symbols with different indexes in the first subframe correspond to different CP lengths. The first numerical value is related to the index of the first OFDM symbol in the first subframe. The first OFDM symbol may have different values ​​for different indexes in the first subframe. The length of the first CP is greater than the first numerical value, which can be understood as the number of sampling points corresponding to the first CP is greater than the number of sampling points corresponding to the first numerical value, or the duration corresponding to the first CP is greater than the duration corresponding to the first numerical value.

[0024] In combination with the first aspect or the second aspect, in one possible implementation, the length of the first CP corresponds to the delay extension of the first channel, and the delay extension indicates the difference in transmission delay of the first time slot in the first transmission path and the second transmission path of the first channel, and the first channel carries the first time slot.

[0025] In this embodiment of the present application, the length of the first CP is greater than the delay spread of the first channel, thereby ensuring that the first OFDM symbol on both the first and second transmission paths can be completely received within the corresponding FFT receiving windows, thereby avoiding signal loss. Furthermore, signals of other OFDM symbols are not received within the FFT receiving window corresponding to the first OFDM symbol, thereby avoiding inter-symbol interference.

[0026] In combination with the first aspect or the second aspect, in a possible implementation, the first transmission path is the first transmission path to arrive among multiple transmission paths of the first channel, and the second transmission path is the last transmission path to arrive among the multiple transmission paths.

[0027] In an embodiment of the present application, the first CP is determined by the transmission delay difference between the first transmission path and the second transmission path, which can ensure that the first OFDM symbol on each transmission path of the multiple transmission paths can fall within the corresponding FFT receiving window, thereby avoiding signal loss and inter-symbol interference.

[0028] In combination with the first aspect or the second aspect, in a possible implementation manner, the length of the first CP is greater than or equal to the delay spread.

[0029] In combination with the first aspect or the second aspect, in a possible implementation, the length of the first CP is determined by the delay extension and at least one of the modulation and coding scheme (MCS), the code rate, and the modulation mode.

[0030] In an embodiment of the present application, different MCS or modulation modes have different error vector magnitude (EVM) requirements. For example, in a high-order modulation mode or a large MCS or a large code rate, a smaller EVM indicator needs to be met to ensure the accuracy of demodulation. In a low-order modulation mode or a small MCS or a small code rate, a larger EVM can also meet the accuracy of demodulation. Therefore, after determining the length of the first CP according to the delay spread of the channel, the length of the first CP can also be adjusted according to the modulation mode or MCS or code rate to meet the demodulation performance.

[0031] In combination with the first aspect or the second aspect, in one possible implementation, the length of the first CP is positively correlated with the MCS; or, the length of the first CP is positively correlated with the modulation order corresponding to the modulation mode; or, the length of the first CP is positively correlated with the code rate.

[0032] In combination with the first aspect or the second aspect, in a possible implementation manner, the multiple OFDM symbols are used to carry PDSCH or physical uplink shared channel (PUSCH).

[0033] In an embodiment of the present application, the first OFDM symbol is the first OFDM symbol among multiple OFDM symbols used to carry PDSCH or PUSCH in the first time slot. By extending the CP length of the first OFDM symbol, the loss of service data on the OFDM symbol can be effectively avoided.

[0034] In combination with the first aspect or the second aspect, in one possible implementation, the end position of the first OFDM symbol is the same as the starting position of the second OFDM symbol, and the first symbol component in the first OFDM symbol is the same as the second symbol component in the second OFDM symbol, wherein the end position of the first symbol component is the end position of the first OFDM symbol, the second symbol component is located before the third symbol component in the second OFDM symbol, the end position of the third symbol component is the same as the end position of the second OFDM symbol, the length of the third symbol component is less than or equal to the length of the second CP, and the second CP is obtained by the third symbol component.

[0035] In an embodiment of the present application, the first OFDM symbol and the second OFDM symbol are continuous in the time domain, and the first OFDM symbol is before the second OFDM symbol. The end position of the first symbol component in the first OFDM symbol is the same as the starting position of the second CP. Since the first symbol component is the same as the second symbol component, the second CP is the same as the third symbol component, and the symbol component composed of the first symbol component and the second CP is the same as the symbol component composed of the second symbol component and the third symbol component, the symbol component composed of the first symbol component and the second CP can be regarded as an equivalent CP of the second symbol, and the equivalent CP length of the second OFDM symbol is the sum of the length of the second CP and the length of the first symbol component, thereby achieving an equivalent extension of the CP of the second OFDM symbol, thereby ensuring that the second OFDM symbol can be fully received by its corresponding receiving window, avoiding signal loss, and making the single-carrier signal have stronger anti-inter-symbol interference (ISI) capability and low adjacent channel leakage ratio (ACLR).

[0036] In combination with the first aspect or the second aspect, in a possible implementation, the fourth symbol component in the first OFDM symbol is the same as the fifth symbol component in the second OFDM symbol, the starting position of the fourth symbol component is the same as the ending position of the first CP, the ending position of the second symbol component is the same as the starting position of the fifth symbol component, the ending position of the fifth symbol component is the same as the starting position of the third symbol component, and the sum of the lengths of the fifth symbol component and the third symbol component is equal to the length of the second CP.

[0037] In the embodiment of the present application, the first symbol component and the second CP are continuous in time delay, and the second symbol component, the fifth symbol component and the third symbol component are continuous in time delay. The symbol component composed of the first symbol component and the second CP is the same as the symbol component composed of the second symbol component, the fifth symbol component and the third symbol component. Therefore, the symbol component composed of the first symbol component and the second CP can be used as the equivalent CP of the second OFDM, realizing the equivalent extension of the CP of the second OFDM symbol, thereby ensuring that the second OFDM symbol can be completely received by its corresponding receiving window, avoiding signal loss.

[0038] In combination with the first aspect or the second aspect, in a possible implementation, the second indication information includes the first TA, the first TA is determined by a first difference or the length of the first CP, and the first difference is the difference between the length of the first CP and the length of the second CP.

[0039] In the embodiment of the present application, the first TA can be determined by the first difference or the length of the first CP, or the first TA can be determined by the extension amount of the first CP. Determining the first TA based on the length of the extended CP or the extension amount of the CP makes the configuration of the first TA more reasonable.

[0040] In combination with the first aspect or the second aspect, in a possible implementation manner, the starting time of the first subframe is the starting time of the sixth symbol component.

[0041] In combination with the first aspect or the second aspect, in a possible implementation method, the value range of the first TA includes (TA2-CP1+ΔT, TA2); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot used to carry PUSCH or PDSCH.

[0042] In an embodiment of the present application, the second subframe can be understood as the first subframe before the first CP is extended, or the subframe that does not support CP extension. The third OFDM symbol can be understood as the first OFDM symbol before the first CP is extended, and the second TA can be understood as the TA corresponding to the first subframe before the first CP is extended. When the first TA takes TA2, the data symbol of the first OFDM symbol on the first transmission path (i.e., the path where the first transmission arrives) is completely received by the first FFT receiving window. When the first TA takes TA2-CP1+ΔT, the data symbol of the first OFDM symbol on the second transmission path (i.e., the path where the last transmission arrives) is completely received by the first FFT receiving window. Therefore, by determining the value range of the first TA based on the second TA, the length of the first CP and the delay extension, it can be ensured that the first OFDM symbols on multiple transmission paths of the channel can be completely received by the first FFT receiving window, thereby avoiding signal loss.

[0043] In combination with the first aspect or the second aspect, in a possible implementation manner, the starting time of the first subframe is the starting time of the first CP.

[0044] In combination with the first aspect or the second aspect, in a possible implementation, the value range of the first TA includes (TA2-CP1+ΔT+ΔD, TA2+ΔD); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the ΔD is the first difference, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot for carrying PUSCH or PDSCH.

[0045] In an embodiment of the present application, when the first TA takes TA2+ΔD, the data symbol of the first OFDM symbol on the first transmission path (i.e., the path where the first transmission arrives) is completely received by the first FFT receiving window. When the first TA takes TA2-CP1+ΔT+ΔD, the data symbol of the first OFDM symbol on the second transmission path (i.e., the path where the last transmission arrives) is completely received by the first FFT receiving window. Therefore, by determining the value range of the first TA based on the second TA, the length of the first CP, the first difference, and the delay spread, it is possible to ensure that the first OFDM symbols on multiple transmission paths of the channel can be completely received by the first FFT receiving window, thereby avoiding signal loss.

[0046] In combination with the first aspect or the second aspect, in a possible implementation method, the second indication information includes at least one of the following information of the first TA: the number of sampling points corresponding to the first TA, the number of modulation symbols corresponding to the first TA, the duration corresponding to the first TA, and the number of unit times corresponding to the first TA.

[0047] In combination with the first aspect or the second aspect, in one possible implementation method, the second indication information is carried by any one of the following: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, physical downlink shared channel PDSCH, uplink control information, physical uplink shared channel PUSCH.

[0048] In a third aspect, an embodiment of the present application provides a communication device for executing the method in the first aspect or any possible implementation of the first aspect. The communication device includes a unit having a function of executing the method in the first aspect or any possible implementation of the first aspect.

[0049] In a fourth aspect, an embodiment of the present application provides a communication device for executing the method in the second aspect or any possible implementation of the second aspect. The communication device includes a unit having the function of executing the method in the second aspect or any possible implementation of the second aspect.

[0050] In the third aspect and the fourth aspect, the above-mentioned communication device and communication device may include a transceiver unit and a processing unit. For a detailed description of the transceiver unit and the processing unit, reference may also be made to the device embodiment shown below.

[0051] In a fifth aspect, an embodiment of the present application provides a communication device, comprising a processor configured to execute the method described in any one of the first to fourth aspects or any possible implementation thereof. Alternatively, the processor is configured to execute a program stored in a memory, and when the program is executed, the method described in any one of the first to second aspects or any possible implementation thereof is executed.

[0052] In a possible implementation, the memory is located outside the communication device.

[0053] In a possible implementation, the memory is located within the communication device.

[0054] In an embodiment of the present application, the processor and the memory may also be integrated into one device, that is, the processor and the memory may also be integrated together.

[0055] In a possible implementation, the communication device further includes a transceiver, where the transceiver is configured to receive a signal or send a signal.

[0056] In a sixth aspect, an embodiment of the present application provides a communication device, which includes a logic circuit and an interface, wherein the logic circuit and the interface are coupled; the logic circuit is used to generate a first time slot; and the interface is used to input the first time slot.

[0057] It can be understood that with respect to the communication device shown in the sixth aspect, reference can also be made to the first aspect or the specific implementation shown below.

[0058] In a seventh aspect, an embodiment of the present application provides a communication device, which includes a logic circuit and an interface, wherein the logic circuit and the interface are coupled; the interface is used to input a first time slot; and the logic circuit is used to parse the first time slot.

[0059] It can be understood that with respect to the communication device shown in the seventh aspect, reference can also be made to the second aspect or the specific implementation shown below.

[0060] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium for storing a computer program, which, when executed on a computer, enables the method shown in any one of the first to second aspects or any possible implementation to be executed.

[0061] In a ninth aspect, an embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is run on a computer, the method shown in any aspect of the first to second aspects or any possible implementation is executed.

[0062] In a tenth aspect, an embodiment of the present application provides a computer program. When the computer program is run on a computer, the method shown in any aspect of the first to second aspects or any possible implementation is executed.

[0063] In the eleventh aspect, an embodiment of the present application provides a communication system, which includes a first communication device and a second communication device, the first communication device is used to execute the method shown in the above-mentioned first aspect or any possible implementation of the first aspect, and the second communication device is used to execute the method shown in the above-mentioned second aspect or any possible implementation of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The following is an introduction to the drawings related to the embodiments of this application.

[0065] FIG1A is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0066] FIG1B is a schematic diagram of the architecture of another communication system provided in an embodiment of the present application;

[0067] FIG2A is a schematic structural diagram of a transmitter provided in an embodiment of the present application;

[0068] FIG2B is a schematic structural diagram of another transmitter provided in an embodiment of the present application;

[0069] FIG3 is a schematic diagram of a delay extension provided in an embodiment of the present application;

[0070] FIG4 is a schematic diagram of the structure of a symbol provided in an embodiment of the present application;

[0071] FIG5 is a schematic diagram of a process of generating a DFT-s-OFDM symbol according to an embodiment of the present application;

[0072] FIG6 is a schematic diagram of a process for generating SC-QAM symbols provided in an embodiment of the present application;

[0073] FIG7A is a schematic diagram of a signal interaction scenario provided by an embodiment of the present application;

[0074] FIG7B is a schematic diagram of another signal interaction scenario provided by an embodiment of the present application;

[0075] FIG8 is a schematic diagram of the structure of an OFDM symbol provided in an embodiment of the present application;

[0076] FIG9 is an interactive diagram of a communication method provided in an embodiment of the present application;

[0077] FIG10 is a schematic diagram of a scenario of OFDM symbol reception provided in an embodiment of the present application;

[0078] FIG11A is a schematic diagram of the structure of another OFDM symbol provided in an embodiment of the present application;

[0079] FIG11B is a schematic diagram of the structure of another OFDM symbol provided in an embodiment of the present application;

[0080] FIG12 is an interactive diagram of another communication method provided in an embodiment of the present application;

[0081] FIG13 is a schematic diagram of a subframe start time provided in an embodiment of the present application;

[0082] FIG14A is a schematic diagram of another OFDM symbol reception scenario provided by an embodiment of the present application;

[0083] FIG14B is a schematic diagram of another OFDM symbol reception scenario provided in an embodiment of the present application;

[0084] FIG15 is a schematic diagram of another subframe start time provided in an embodiment of the present application;

[0085] FIG16A is a schematic diagram of another OFDM symbol reception scenario provided in an embodiment of the present application;

[0086] FIG16B is a schematic diagram of another OFDM symbol reception scenario provided by an embodiment of the present application;

[0087] FIG17 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0088] FIG18 is a schematic structural diagram of another communication device provided in an embodiment of the present application;

[0089] FIG19 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0090] The terms "first" and "second" in the specification, claims and drawings of this application are only used to distinguish different objects, and are not used to limit the order, timing, priority or importance of multiple objects. In the embodiments of the present application, "multiple" refers to two or more. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. In addition, the character " / ", unless otherwise specified, generally indicates that the objects associated before and after are in an "or" relationship.

[0091] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It will be understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0092] It should be understood that in the present application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0093] The technical solutions provided in the embodiments of the present application can be applied to various communication systems, for example, satellite communication systems and systems integrating satellite communication and cellular networks. Among them, the cellular network system may include but is not limited to: 5G system, global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, advanced long term evolution (LTE-A) system, new radio (NR) system, NR system evolution system, LTE on unlicensed band (LTE-based access to unlicensed spectrum, LTE-U) system, NR on unlicensed band (NR-based access to unlicensed spectrum, NR-U) system, universal mobile telecommunication system (UMTS), world-wide interoperability for microwave access (WiMAX) communication system, wireless local area network (WLAN) system. area networks (WLAN), wireless fidelity (WiFi), next generation communication systems or other communication systems, etc.Generally speaking, traditional communication systems support a limited number of connections and are easy to implement. However, with the development of communication technology, mobile communication systems will not only support traditional communications, but will also support, for example: device to device (D2D) communication, machine to machine (M2M) communication, machine type communication (MTC), vehicle to vehicle (V2V) communication, and other communication systems that will evolve in the future. The embodiments of the present application can also be applied to these communication systems. Satellite communication systems can include various non-terrestrial network systems, such as satellites or unmanned aircraft systems (UAS) platforms, which transmit wireless frequencies, and are not listed here one by one.

[0094] The technical solution provided in this application can also be applied to machine type communication (MTC), long term evolution-machine (LTE-M), device-to-device (D2D) network, machine-to-machine (M2M) network, Internet of Things (IoT) network or other networks. Among them, the IoT network can include, for example, the Internet of Vehicles. Among them, the communication mode in the Internet of Vehicles system is collectively referred to as vehicle-to-everything (V2X, X can represent anything). For example, the V2X can include: vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, vehicle-to-pedestrian (V2P) communication or vehicle-to-network (V2N) communication, etc. For example, in Figure 1A or Figure 1B shown below, terminal devices can communicate with each other through D2D technology, M2M technology or V2X technology, etc.

[0095] As shown in FIG. 1A or FIG. 1B , the communication system provided in an embodiment of the present application may include at least one access network device and at least one terminal device.

[0096] The introductions to access network equipment and terminal equipment are as follows:

[0097] Exemplarily, the access network device may be a next-generation node B (gNB), a next-generation evolved node B (ng-eNB), or an access network device in future 6G communications. The access network device may be any device with wireless transceiver capabilities, including but not limited to the base stations shown above. The base station may also be a base station in a future communication system, such as a sixth-generation communication system. Optionally, the access network device may be an access node, wireless relay node, wireless backhaul node, etc. in a wireless local area network (Wi-Fi) system. Optionally, the access network device may be a wireless controller in a cloud radio access network (CRAN) scenario. Optionally, the access network device may be a wearable device or an in-vehicle device. Optionally, the access network device may also be a small cell, a transmission reception point (TRP) (or also referred to as a transmission point), a transmission measurement function (TMF), etc. It is understood that the access network device may also be a base station in a future evolved public land mobile network (PLMN), etc.

[0098] In some deployments, a base station (such as a gNB) can be composed of a centralized unit (CU) and a distributed unit (DU). That is, the functions of the base station in the access network are split, with some functions of the base station deployed in a CU and the remaining functions deployed in the DU. Multiple DUs share a single CU, which can save costs and facilitate network expansion. In other deployments of base stations, the CU can also be divided into a CU-control plane (CP) and a CU-user plane (UP). In still other deployments of base stations, the base station can also be an open radio access network (ORAN) architecture, etc. This application does not limit the specific type of base station.

[0099] For ease of description, the following will take the access network device as a base station as an example to introduce the method involved in this application.

[0100] For example, the terminal device may also be referred to as user equipment (UE), terminal, etc. A terminal device is a device with wireless transceiver capabilities that can be deployed on land, including indoors or outdoors, handheld, wearable, or vehicle-mounted; can also be deployed on water, such as on a ship; and can also be deployed in the air, such as on an airplane, balloon, or satellite. A terminal device can be a mobile phone, a tablet computer, a computer with wireless transceiver capabilities, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical care, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, customer-premises equipment (CPE), etc. It is understandable that the terminal device can also be a terminal device in a future 6G network or a terminal device in a future evolved PLMN, etc.

[0101] It can be understood that the terminal device shown in this application can not only include vehicles in the Internet of Vehicles (such as complete vehicles), but also include vehicle-mounted devices or vehicle-mounted terminals in the Internet of Vehicles. This application does not limit the specific form of the terminal device when applied to the Internet of Vehicles.

[0102] For ease of description, the following will take the terminal device as UE as an example to introduce the method involved in this application.

[0103] The communication system shown in Figure 1A includes a base station and multiple UEs, such as UE1 and UE2 in Figure 1A. In this communication system, the base station can send downlink signals such as configuration information or downlink control information (DCI) to UE1 and UE2, and UE1 and UE2 can send uplink signals such as SRS or physical uplink shared channel (PUSCH) to the base station. It is understood that the communication method between UEs can be referred to the above description and will not be detailed here.

[0104] The communication system shown in Figure 1B includes one UE and multiple base stations, such as base station 1, base station 2, and base station 3. In the communication system, base station 1, base station 2, and base station 3 can simultaneously transmit data and control signaling for the UE.

[0105] Each of the aforementioned communication devices, such as the base station and UE in Figure 1A or Figure 1B, may be configured with multiple antennas. These multiple antennas may include at least one transmit antenna for sending signals and at least one receive antenna for receiving signals. The embodiments of this application do not limit the specific structure of each communication device. Optionally, the communication system may also include other network entities such as a network controller and a mobility management entity, but the embodiments of this application are not limited thereto.

[0106] In the communication system shown in FIG1A or FIG1B , the terminal device and the network device can communicate based on orthogonal frequency-division multiplexing (OFDM) symbols or single carrier symbols. For example, discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols or single carrier quadrature amplitude modulation (SC-QAM) symbols. Exemplarily, when the terminal device and the network device communicate via a DFT-s-OFDM waveform, as shown in FIG2A , the transmitter includes but is not limited to the following functional modules:

[0107] Modulation module: used to map the coded bits into modulation symbols according to the modulation order. Modulation symbols can also be called complex symbols.

[0108] Time domain resource mapping module: used to divide all modulation symbols in a time slot into multiple block signals according to mapping rules or arrangement rules, or called serial-to-parallel conversion;

[0109] Transform domain precoding module (also called discrete Fourier transform module): used to convert multiple block signals into signals that can be mapped to frequency domain subcarriers in units of block signals;

[0110] Subcarrier mapping module: used to map signals that can be mapped to frequency domain subcarriers to subcarriers.

[0111] DFT-s-OFDM symbol generation module: used to perform fast inverse Fourier transform on the data of the subcarrier mapping module and add CP to obtain DFT-s-OFDM symbols, and then send the DFT-s-OFDM symbols to the intermediate frequency module.

[0112] As shown in Figure 2B, when the terminal device and the network device communicate through the SC-QAM waveform, the structure of the transmitter includes but is not limited to the following functional modules: modulation module, time domain resource mapping module, CP addition module, and SC-QAM symbol generation module.

[0113] Exemplarily, the input of the time domain resource mapping module shown in Figure 2A or Figure 2B may include modulation symbols and a known sequence, and the output of the time domain resource mapping module may include a complex array or vector of DFT-s-OFDM symbols or SC-QAM symbols.

[0114] Optionally, the input of the time domain resource mapping module may further include a reference signal sequence, such as a phase tracking reference signal (PTRS) sequence.

[0115] The following is a brief description of the technical concepts involved in the embodiments of this application:

[0116] 1. Latency Extension

[0117] Because signals are subject to refraction and reflection during transmission within a channel, they travel through multiple transmission paths to the receiving end. This phenomenon is also known as the multipath effect of the channel, and the channel itself is also known as a multipath channel. The signal received by the receiving end includes signals transmitted along multiple transmission paths, and the signals on different transmission paths arrive at different times. Delay spread is the difference in arrival times between different transmission paths within the channel. As shown in Figure 3, a signal can be transmitted via a first transmission path and a second transmission path. The signal on the first transmission path arrives at time T0, and the signal on the second transmission path arrives at time T1. The delay spread is T1-T0.

[0118] For example, the arrival time difference between the transmission path where the first transmission arrives and the transmission path where the last transmission arrives in the channel may be referred to as the maximum delay spread of the channel.

[0119] In a multipath channel, signals transmitted along different transmission paths arrive at the receiver at different times, causing intersymbol interference (ISI). For example, in Figure 3, the first symbol on the second transmission path falls within the time domain of the second symbol on the first transmission path. This means that the receiver receives both symbols simultaneously, causing ISI.

[0120] 2. Cyclic prefix (CP)

[0121] The cyclic prefix (CP) can serve as a guard interval between symbols to mitigate channel multipath. The transmitter can copy a portion of the signal at the end of each symbol (i.e., the symbol component) and append it to the position preceding the symbol, thereby obtaining the symbol's CP and increasing the guard interval. Figure 4 illustrates the time-domain structure of the CP as the guard interval between symbols. In Figure 4, two symbols are shown: symbol 1 and symbol 2. The CP of symbol 1 refers to the cyclic structure formed by copying and appending a segment of the symbol component from the point where the CP is intercepted to the end position of symbol 1 to the beginning of symbol 1 (e.g., CP 1 in Figure 4). The CP of symbol 2 refers to the cyclic structure formed by copying and appending a segment of the symbol component from the point where the CP is intercepted to the end position of symbol 2 to the beginning of symbol 2 (e.g., CP 2 in Figure 4). The CP of symbol 2 serves as the guard interval between symbols 1 and 2, while the CP of symbol 1 serves as the guard interval between symbol 1 and the symbol immediately preceding it (not shown in Figure 4).

[0122] Exemplarily, when the length of the CP of a symbol is greater than the maximum delay spread of the channel, the linear convolution of the channel and the transmit signal can be converted into a circular convolution of the channel and the transmit signal, thereby avoiding the generation of ISI.

[0123] Exemplarily, the above symbols may include OFDM symbols, DFT-s-OFDM symbols, SC-QAM symbols, etc.

[0124] A DFT-s-OFDM symbol represents a single carrier symbol whose waveform is a DFT-s-OFDM waveform. A DFT-s-OFDM symbol includes a data symbol and a CP. The length of the data symbol is determined by the subcarrier spacing (SCS). Similarly, the length of the CP and the length of the DFT-s-OFDM symbol are determined by the SCS.

[0125] For example, the SCS, the length of the data symbol, and the length of the CP may satisfy the following formula:

[0126] Among them, T data Indicates the length of the data symbol (in μs), T cp Indicates CP length (unit: μs), s data Indicates the number of sampling points corresponding to the length of the data symbol, s cp Indicates the number of sampling points corresponding to the length of CP. From the above formula, we can see that the larger the SCS, the shorter the CP length.

[0127] Figure 5 is a flow chart of a DFT-s-OFDM symbol generation process provided by an embodiment of the present application. As shown in Figure 5, the transmitter first modulates the encoded bit stream to obtain modulation symbols (modulation methods include pi / 2-binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), 64QAM, 256QAM, etc.); the transmitter groups the modulation symbols according to scheduling parameters such as bandwidth, that is, the modulation symbols are converted into serial (sequential) and parallel (parallel) (S / P). The grouped modulation symbols are first subjected to discrete Fourier transformation (DFT) (or frequency domain precoding), and then subcarrier mapping is performed; after subcarrier mapping, the transmitter will perform inverse fast Fourier transform (IFFT) and add CP operations. The transmitter performs serial-to-parallel conversion (P / S) on the signal after adding the CP to obtain a DFT-s-OFDM symbol.

[0128] Figure 6 is a schematic diagram of a SC-QAM symbol generation process according to an embodiment of the present application. As shown in Figure 6, the transmitter first modulates the coded bit stream to obtain modulation symbols and performs parallel-to-serial (S / P) conversion on the modulation symbols. The transmitter then adds a CP to the grouped modulation symbols, performs upsampling, and performs filtering to obtain SC-QAM symbols.

[0129] 3. Timing Advance (TA)

[0130] During uplink transmission, since the distances from different terminal devices to the network device are different, the time difference between the signals sent by different terminal devices and arriving at the network device is also different. When the terminal device receives the downlink signal sent by the network device and then sends the uplink signal, it will arrive at the network device at different times. In order to ensure the orthogonality of uplink transmission and avoid intra-cell interference, the network device requires that the time at which signals from different terminals in the same subframe but different frequency domain resources arrive at the network device is basically aligned. For example, the arrival time difference of the uplink signals sent by different terminal devices is within the CP range, so that the network device can correctly receive the uplink data sent by the terminal. Therefore, the uplink transmission of the terminal device needs to be timed in advance, and TA is the difference between the start time of receiving the downlink subframe (that is, the arrival time of the downlink subframe) and the time of transmitting the uplink subframe (the uplink subframe sending time).

[0131] If the terminal device sends an uplink signal after receiving a downlink signal, the network device will no longer be able to receive the uplink signal within the expected time, causing the terminal device and the network device to be out of synchronization in uplink timing. For example, as shown in Figure 7A, the network device sends a downlink signal at time T0, the terminal device receives the downlink signal and sends an uplink signal at time T1, and the network device receives the uplink signal at time T2, that is, the network device can no longer receive the uplink signal at the expected time (time T0), causing the network device and the terminal device to be out of synchronization in uplink timing. Therefore, the terminal device needs to advance the timing when sending the uplink signal, for example, TA=2*D1, where D1 is the transmission delay between the terminal device and the network device. As shown in Figure 7B, the network device sends a downlink signal at time T0, the terminal device receives the downlink signal at time T1, the terminal device sends an uplink signal at time T3, and the network device receives the uplink signal at time T0, that is, the network device receives the uplink signal within the expected time, so that the network device and the terminal device are synchronized in uplink. Among them, the time difference between time T1 and time T3 is TA=2*D1.

[0132] For example, the timing advance TA satisfies the following formula: TA=(N TA +N TA_offset )*T C (3)

[0133] Among them, N TA_offset is the fixed offset used to calculate the timing advance, T C is the time unit, N TAThe timing advance command (TAC) field may be acquired or updated via a random access response (RAR) or a media access control (MAC) control element (CE).

[0134] The N TA_offset It can be configured by the n-TimingAdvanceOffset of the serving cell. TA_offset The value of can be 0, 25600, 39936, or 13792, and the unit is Tc. For example, Tc is 0.5 nanoseconds. If the serving cell does not configure n-TimingAdvanceOffset signaling for the terminal device, N TA_offset Refer to Table 7.1.2-2 in Protocol 38.133 for the value.

[0135] Please refer to Figure 8, which is a structural diagram of an OFDM symbol provided in an embodiment of the present application. As shown in Figure 8, the length of the fast Fourier transform (FFT) receiving window corresponding to each OFDM symbol is the length of the data symbol of an OFDM symbol, and the starting position of the FFT receiving window corresponding to each OFDM symbol is determined according to the end position of the CP. Exemplarily, the starting position of the FFT receiving window corresponding to the first OFDM symbol is the end position of the CP corresponding to the first OFDM symbol in the received signal corresponding to the first transmission path. The starting position of the FFT receiving window corresponding to the second OFDM symbol is the end position of the CP corresponding to the second OFDM symbol in the received signal corresponding to the first transmission path.

[0136] Exemplarily, the first OFDM symbol is transmitted via the first transmission path and the second transmission path. When the transmission delay difference (i.e., delay spread) between the first transmission path and the second transmission path is greater than the length of the CP (i.e., the first CP) of the first OFDM symbol, the received signal corresponding to the second transmission path cannot completely fall into the FFT receiving window determined in the above manner. The first transmission path and the second transmission path are two different transmission paths among the multiple transmission paths of the channel. Specifically, for the first OFDM symbol, a portion of the signal that reaches the receiving end after passing through the second transmission path will be lost (as shown by the diagonal square in Figure 8), wherein the portion of the signal shown by the diagonal square does not fall into the FFT receiving window corresponding to the first OFDM symbol, and the portion of the signal is not copied before the starting position of the first OFDM symbol. Therefore, the portion of the signal is a lost useful signal, which will reduce the demodulation performance and affect the coverage. In addition, when the first OFDM symbol is the OFDM symbol where the DMRS is located, the estimation accuracy of the channel estimated based on the DMRS will be reduced.

[0137] In view of this, an embodiment of the present application provides a symbol processing method that can reduce signal loss and inter-symbol interference, thereby improving demodulation performance. The method is applied to the communication system shown in Figure 1A or Figure 1B, or the method is applied to a first communication device and a second communication device, the first communication device can be the terminal device or network device described above, and the second communication device can be the network device or terminal device described above.

[0138] It is understandable that although the method shown below does not involve a relay node, those skilled in the art will know that when a sender and a receiver communicate, a forwarding operation can be performed through a relay node.

[0139] It is understood that the interaction diagrams in this application use network devices and terminal devices as examples of the execution entities of the interaction diagrams to illustrate the method, but this application does not limit the execution entities of the interaction diagrams. For example, the network device in the interaction diagram can also be a chip, chip system, or processor that supports the network device to implement the method, or a logical node, logic module, or software that can implement all or part of the network device functions; the terminal device in the interaction diagram can also be a chip, chip system, or processor that supports the terminal to implement the method.

[0140] Please refer to Figure 9, which is an interactive diagram of a communication method provided by an embodiment of the present application. As shown in Figure 9, the method includes but is not limited to the following steps.

[0141] 901. A first communication device generates a first time slot, wherein the first time slot includes multiple OFDM symbols, the multiple OFDM symbols include a first OFDM symbol and a second OFDM symbol, the first OFDM symbol is the first OFDM symbol in the multiple OFDM symbols, the first OFDM symbol includes a first CP, the second OFDM symbol includes a second CP, the length of the first CP is greater than the length of the second CP, the length of the first CP is greater than a first value, and the first value corresponds to the subcarrier spacing.

[0142] Exemplarily, the length of the first CP may include the number of modulation symbols corresponding to the first CP, the number of sampling points corresponding to the first CP, or the duration of the first CP. The length of the first CP is greater than the length of the second CP, that is, the number of modulation symbols corresponding to the first CP is greater than the number of modulation symbols corresponding to the second CP, or the number of sampling points corresponding to the first CP is greater than the number of sampling points corresponding to the second CP, or the duration of the first CP is greater than the duration of the second CP.

[0143] The multiple OFDM symbols are used to carry a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH), that is, the first OFDM symbol is the first OFDM symbol among the multiple OFDM symbols used to carry PDSCH or PUSCH in the first time slot.

[0144] Exemplarily, the first value may be the length of the CP specified in an existing protocol. The first value corresponds to the subcarrier spacing, that is, the first value may be different under different subcarrier spacings. For example, the correspondence between the first value and the subcarrier spacing may be as shown in Table 1. As shown in Table 1, when the SCS is 120 kilohertz (kHz), the first value may be 586 nanoseconds (ns). When the SCS is 480 kHz, the first value may be 146 ns.

[0145] Table 1

[0146] It can be understood that the mapping relationship between the subcarrier spacing and the first numerical value shown in Table 1 is only an example, and the value of the first numerical value shown in Table 1 should not be understood as a limitation to the present application. The first numerical value in the embodiment of the present application may also take other values.

[0147] In one possible implementation, the first time slot is included in the first subframe, and each symbol in the first subframe may correspond to an index. The first value is related to the index of the first OFDM symbol in the first subframe. The first value may have different values ​​depending on the index of the first OFDM symbol in the first subframe. For example, the index of the first OFDM symbol in the first subframe is 0 or 7*2. μ In the case of the first value is X1; the index of the first OFDM symbol in the first subframe is not 0 or 7*2 μ In the case of , the first value is X2. Where X1 is greater than X2. For example, the difference between X1 and X2 is 16β. Where β corresponds to the maximum number of subcarriers and the maximum subcarrier spacing of the transmission bandwidth.

[0148] For example, the index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of -μ +16β. Or, the index of the first OFDM symbol in the first subframe is not equal to 0 or 7*2 μ In the case of -μ . Where μ corresponds to the subcarrier spacing configuration.

[0149] For example, β may be κ, where κ is the ratio of Ts to Tc, i.e., κ=Ts / Tc=64, where Ts and Tc are both time units. Tc=1 / (Δf max ·N f ), where Δf max is the maximum subcarrier spacing of the transmission bandwidth in NR, N f The number of sampling points corresponding to the maximum number of subcarriers in the transmission bandwidth of NR, such as Δf max =480·10 3 Hz, N f =4096. Ts = 1 / (Δf ref ·N f,ref ), =15·10 3 Hz, N f,ref =2048. ref is the subcarrier spacing of the transmission bandwidth in LTE, N f,ref is the number of sampling points corresponding to the maximum number of subcarriers in the transmission bandwidth in LTE. It is understood that the value of κ can also be found in the relevant description in Section 4.1 of protocol 38.211.

[0150] It can be understood that the length of the first CP is greater than the first value, which can be understood as the number of sampling points corresponding to the first CP is greater than the number of sampling points corresponding to the first value. That is, the index of the first OFDM symbol in the first subframe is 0 or 7*2 μIn the case of the first CP, the number of sampling points is greater than 144*2 -μ +16; the index of the first OFDM symbol in the first subframe is not 0 or 7*2 μ In the case of the first CP, the number of sampling points corresponding to the first CP is greater than 144*2 -μ .

[0151] Exemplarily, the duration corresponding to the first value can be determined by the value of the first value. For example, the duration corresponding to the first value is expressed as the product of the value of the first value and Tc. The length of the first CP is greater than the first value, which can be understood as the duration of the first CP being greater than the duration corresponding to the first value. That is, the index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of the first CP duration is greater than (144κ*2 -μ +16κ)*Tc; the index of the first OFDM symbol in the first subframe is not 0 or 7*2 μ In the case of the first CP duration is greater than 144κ*2 -μ *Tc.

[0152] For example, the length of the second CP may be specified by the protocol. For example, the index of the second OFDM symbol in the first subframe is 7*2 μ In the case of , the duration of the second CP is equal to (144κ*2 -μ +16κ)*Tc; the index of the second OFDM symbol in the first subframe is not 0 or 7*2 μ In the case of -μ *Tc.

[0153] In some possible implementations, the length of the first CP corresponds to a delay spread of the first channel, where the delay spread indicates the difference in transmission delay of a first time slot along a first transmission path and a second transmission path of the first channel, and the first channel carries the first time slot. When the first time slot is transmitted through the first channel, it can be transmitted via multiple transmission paths of the first channel, where the first transmission path and the second transmission path are two different transmission paths among the multiple transmission paths. The delay spread of the first channel is the difference in transmission delay between the first transmission path and the second transmission path, that is, the delay spread of the first channel is the arrival time difference between the first transmission path and the second transmission path.

[0154] In this implementation, the length of the first CP can be determined by the delay spread of the first channel. For example, the length of the first CP is greater than or equal to the delay spread, so that the first OFDM symbol can be completely received by the corresponding FFT receiving window, avoiding signal loss and inter-symbol interference. As shown in Figure 10, for the second transmission path, part of the signal of the first OFDM symbol is after the first FFT receiving window, but the part of the signal is copied to the first CP, so the part of the signal is not lost, that is, the first OFDM symbol transmitted on the second transmission path can be completely received by the first FFT receiving window. And no other OFDM symbols will be received in the first FFT receiving window, avoiding inter-symbol interference.

[0155] Exemplarily, the first transmission path is the first transmission path to arrive among multiple transmission paths of the first channel, and the second transmission path is the last transmission path to arrive among the multiple transmission paths. This delay spread may also be referred to as the maximum delay spread. The length of the first CP is greater than or equal to the maximum delay spread of the first channel, so that the first OFDM symbol can be fully received by the corresponding receiving window, avoiding signal loss and inter-symbol interference, thereby improving demodulation performance and enhancing coverage.

[0156] In a possible implementation, the length of the first CP is determined by delay spread and at least one of a modulation and coding scheme (MCS), a code rate, and a modulation mode.

[0157] Exemplarily, different MCS or modulation modes have different error vector magnitude (EVM) requirements. For example, in high-order modulation modes or large MCS or large code rates, a smaller EVM indicator needs to be met to ensure the accuracy of demodulation. In low-order modulation modes or small MCS or small code rates, a larger EVM can also meet the accuracy of demodulation. The impact of the loss of the first symbol part of the received signal under high-order modulation or large MCS or large code rate on the demodulation performance is greater than that under low-order modulation or small MCS or small code rate. Therefore, after determining the length of the first CP according to the delay spread of the channel, the length of the first CP can also be adjusted according to the modulation mode or MCS or code rate to meet the demodulation performance. For example, the length of the first CP is positively correlated with the MCS; or, the length of the first CP is positively correlated with the modulation order corresponding to the modulation mode; or, the length of the first CP is positively correlated with the code rate.

[0158] It is understood that the MCS in the embodiment of the present application may refer to the index of the MCS. A large MCS means that the index of the MCS is large.

[0159] 902. A first communication device sends a first time slot, and correspondingly, a second communication device receives the first time slot.

[0160] In one possible implementation, the end position of the first OFDM symbol is the same as the starting position of the second OFDM symbol, and the first symbol component in the first OFDM symbol is the same as the second symbol component in the second OFDM symbol, wherein the end position of the first symbol component is the end position of the first OFDM symbol, the second symbol component is located before the third symbol component in the second OFDM symbol, the end position of the third symbol component is the same as the end position of the second OFDM symbol, the length of the third symbol component is less than or equal to the length of the second CP, and the second CP is obtained from the third symbol component.

[0161] As an example, as shown in FIG11A , the second CP can be obtained by copying the third symbol component, that is, the second CP is the same as the third symbol component. The end position of the first OFDM symbol is the same as the starting position of the second OFDM symbol, that is, the first OFDM symbol and the second OFDM symbol are continuous in the time domain, and the first OFDM symbol is before the second OFDM symbol. The end position of the first symbol component in the first OFDM symbol is the same as the starting position of the second CP. Since the first symbol component is the same as the second symbol component, the second CP is the same as the third symbol component, and the symbol component composed of the first symbol component and the second CP is the same as the symbol component composed of the second symbol component and the third symbol component, the symbol component composed of the first symbol component and the second CP can be regarded as an equivalent CP of the second symbol, and the equivalent CP length of the second OFDM symbol is the sum of the length of the second CP and the length of the first symbol component.

[0162] As another example, as shown in FIG11B , the fourth symbol component in the first OFDM symbol is the same as the fifth symbol component in the second OFDM symbol, the starting position of the fourth symbol component is the same as the ending position of the first CP, the ending position of the second symbol component is the same as the starting position of the fifth symbol component, the ending position of the fifth symbol component is the same as the starting position of the third symbol component, and the sum of the lengths of the fifth symbol component and the third symbol component is equal to the length of the second CP. In this example, the second CP is obtained by copying the fifth symbol component and the third symbol component. The symbol component composed of the first symbol component and the second CP is the same as the symbol component composed of the second symbol component, the fifth symbol component, and the third symbol component. Therefore, the symbol component composed of the first symbol component and the second CP can be used as the equivalent CP of the second OFDM.

[0163] In this implementation, the first symbol component and the second CP can be understood as the CP of the second OFDM symbol, that is, the first symbol component and the second CP constitute an equivalent CP of the second OFDM symbol, thereby achieving an equivalent extension of the CP of the second OFDM symbol, thereby ensuring that the second OFDM symbol can be completely received by its corresponding receiving window, avoiding signal loss, and making the single-carrier signal have stronger anti-ISI capability and low adjacent channel leakage ratio (ACLR).

[0164] In the embodiment of the present application, two symbol components being identical (e.g., the first symbol component and the second symbol component, or the fourth symbol component and the fifth symbol component) may include: the two symbol components containing identical content, and the two symbol components having identical time lengths. The two symbol components containing identical content can be understood as meaning that, before performing DFT, the modulation symbols corresponding to the two components are identical.

[0165] It is understood that the two symbol components in the embodiment of the present application are not necessarily identical in an absolute sense, but may also be approximately identical. For example, due to the filter tailing effect, there may be a slight deviation between the two symbol components.

[0166] 903. The second communication device parses the first time slot.

[0167] In one possible implementation, in a multiple transmission reception point (TRP) scenario, a second communication device receives subframes from a first communication device and a third communication device. In this scenario, the length of a first CP is greater than or equal to a first delay difference, where the first delay difference is the difference between a first transmission delay and a second transmission delay, where the first transmission delay is the transmission delay of a signal from the first communication device to the second communication device, and the second transmission delay is the transmission delay of a signal from the third communication device to the second communication device.

[0168] Exemplarily, the first communication device may be a terminal device or a network device. If the first communication device is a terminal device, the first communication device may receive configuration information sent by the network device, where the configuration information is used to configure the length of the first CP. If the first communication device is a network device, the first communication device may determine the delay spread of the channel based on channel measurement, and determine the length of the first CP based on the delay spread of the channel.

[0169] In an embodiment of the present application, the length of the first CP can be extended, that is, more signals are copied from the tail of the first OFDM symbol to the front of the first OFDM symbol, so that the first OFDM symbol transmitted on each transmission path can fall within the corresponding FFT receiving window, thereby reducing signal loss and improving demodulation performance.

[0170] It should be noted that the symbols or OFDM symbols involved in the embodiments of the present application may refer to DFT-s-OFDM symbols, or SC-QAM symbols, or other symbols, and the embodiments of the present application are not limited to this.

[0171] Please refer to Figure 12, which is an interactive diagram of a communication method provided in an embodiment of the present application. The method can be applied to the communication system shown in Figure 1A or Figure 1B, or the method can be applied to a terminal device or a network device, the terminal device can be the terminal device or the first communication device described above, and the network device can be the network device or the second communication device described above. As shown in Figure 12, the method includes but is not limited to the following steps.

[0172] 1201. The network device sends first indication information. Correspondingly, the terminal device receives the first indication information, where the first indication information indicates the length of the first CP.

[0173] As shown in FIG11A or FIG11B, in a possible implementation, for multiple OFDM symbols carrying PUSCH in the first time slot, part of the signal of the previous OFDM symbol can be copied to the next OFDM symbol by cross-symbol replication, thereby constructing the equivalent CP of the next OFDM symbol. For example, part of the signal of the first OFDM symbol is copied to the second OFDM symbol to construct the equivalent CP length of the second OFDM symbol, thereby equivalently extending the length of the CP of the second OFDM symbol. The equivalent CP length is greater than the delay spread and can better resist ISI. However, in this implementation, the equivalent CP is effective from the second OFDM symbol in the multiple OFDM symbols, and the equivalent CP of the first OFDM symbol in the multiple OFDM symbols cannot be constructed. Therefore, the embodiment of the present application can extend the CP length of the first OFDM symbol (i.e., the first OFDM symbol) in the multiple OFDM symbols so that the length of the CP of the first OFDM symbol is greater than or equal to the delay spread, so that the first OFDM symbol can be fully received.

[0174] Exemplarily, the first CP is the CP of the first OFDM symbol, and the first OFDM symbol is the first OFDM symbol among multiple OFDM symbols carrying PUSCH in the first time slot. The network device can indicate the length of the first CP through the first indication information to instruct the terminal device to extend the length of the CP of the first OFDM symbol. For example, the first indication information includes at least one of the following: the number of modulation symbols corresponding to the extension amount of the first CP, the number of sampling points corresponding to the extension amount of the first CP, the number of modulation symbols corresponding to the first CP, and the number of sampling points corresponding to the first CP. It can be understood that the extension amount of the first CP is the difference between the length of the first CP after extension and the length of the first CP before extension.

[0175] Exemplarily, the first indication information is carried in any one of the following items: downlink control information, radio resource control signaling, MAC CE, system message SIB, and PDSCH.

[0176] For example, before the network device sends the first indication information, the terminal device may report terminal capabilities to the network device, for example, whether the terminal device supports the first symbol CP extension operation and the CP extension amount supported by the terminal device or the length of the extended CP. If the terminal device supports the first symbol CP extension operation, the network device sends the first indication information. If the terminal device does not support the first symbol CP extension operation, the network device does not send the first indication information.

[0177] It can be understood that for the specific description of the first CP and the first OFDM symbol, reference can be made to the relevant description in step 901 in Figure 9, which will not be detailed here.

[0178] In one possible implementation, the network device may store multiple optional first CP lengths and indicate one or more of the multiple first CP lengths through the first indication information. In this example, the network device may pre-configure one or more first CP lengths for the terminal device to improve configuration efficiency.

[0179] In one possible implementation, the network device determines the length of the first CP based on the delay spread of the first channel, which carries the first time slot. When the delay spread of the channel is greater than the first CP, part of the received signal of the first OFDM symbol will be lost, that is, the delay spread of the channel will directly affect whether the received signal of the first OFDM symbol is complete. Therefore, the length of the first CP is directly related to the channel. In this example, the network device can first determine the channel that carries the first time slot, and then configure the length of the first CP according to the delay spread of the channel to directly avoid the loss of part of the received signal of the first symbol under the channel.

[0180] In another possible implementation, the network device determines the length of the first CP based on the channel delay spread and at least one of the MCS, modulation scheme, and code rate. For example, the network device may preconfigure the length of the first CP based on the channel delay spread and then adjust the length of the first CP based on the MCS, modulation scheme, and code rate.

[0181] As an example, the network device configures the length of the first CP or the extension of the first CP through the MCS or modulation mode. For example, the network device can configure the length of the first CP or the extension of the first CP based on the mapping relationship between the length of the first CP or the extension of the first CP and the MCS or modulation mode or code rate, and the terminal device can determine the length of the first CP or the extension of the first CP based on the mapping relationship and the MCS or modulation mode or code rate corresponding to the first time slot. The above-mentioned first indication information indicates the mapping relationship between the length of the first CP or the extension of the first CP and the MCS or modulation mode or code rate.

[0182] For example, Table 2 shows a mapping relationship between an MCS and the extension amount (ΔK) of the first CP. As shown in Table 2, the network device can pre-configure two extension amounts of the first CP (configuration 1 and configuration 2), and then adjust the extension amount of the first CP based on the MCS. For example, for the extension amount of the first CP under configuration 1, when the index of the MCS corresponding to the first time slot falls within range 1, the value of the extension amount of the first CP is within the range (a1, b1); when the index of the MCS corresponding to the first time slot falls within range 2, the value of the extension amount of the first CP is within the range (a2, b2).

[0183] Table 2

[0184] It can be understood that in Table 2, a1, b1, a2, b2, etc. are only used to represent different value ranges of the extension amount of the first CP. The ranges of (a1, b1) and (a2, b2) may overlap or not overlap, and this application does not limit this. The value range of MCS can also be replaced by the specific value of MCS, and the larger the value of MCS, the larger the extension amount of the corresponding first CP, that is, the length of the first CP is proportional to MCS. For example, when range 1 is (0,3) and range 2 is (4,6), a1 is less than a2.

[0185] It can be understood that regarding the way in which the network device configures the length of the first CP through the mapping relationship between the length of the first CP and the MCS, you can refer to the way in which the network device configures the extension amount of the first CP through the mapping relationship between the length of the first CP and the MCS, which will not be described in detail here.

[0186] In some possible implementations, the MCS shown in Table 2 can be replaced with the code rate corresponding to the MCS, and the length of the first CP is positively correlated with the code rate corresponding to the MCS. A larger code rate corresponds to a larger length of the corresponding first CP or a larger extension of the first CP.

[0187] Table 3 shows a mapping relationship between a modulation mode and the extension amount (ΔK) of the first CP. As shown in Table 3, the network device can pre-configure two extension amounts of the first CP (Configuration 1 and Configuration 2) and then adjust the extension amount of the first CP based on the modulation mode. For example, for the extension amount of the first CP under Configuration 1, when the modulation mode corresponding to the first time slot is BPSK, the value of the extension amount of the first CP is within the range of (e1, f1); when the modulation mode corresponding to the first time slot is QPSK, the value of the extension amount of the first CP is within the range of (e2, f2).

[0188] Table 3

[0189] It is understandable that in Table 3, e1, f1, e2, f2, etc. are only used to represent different value ranges of the extension amount of the first CP. The ranges of (e1, f1) and (e2, f2) may or may not overlap, and this application does not impose any restrictions on this. The modulation mode in Table 3 can also be replaced by the modulation order corresponding to the modulation mode, and the larger the modulation order, the larger the corresponding extension amount of the first CP, that is, the length of the first CP is proportional to the modulation order.

[0190] It can be understood that regarding the network device configuring the length of the first CP through the mapping relationship between the length of the first CP and the modulation mode, reference can be made to the network device configuring the extension amount of the first CP through the mapping relationship between the length of the first CP and the modulation mode.

[0191] It can be understood that Table 2 and Table 3 are only a configuration method of the extension amount of the first CP provided in an embodiment of the present application, and the modulation mode or the mapping relationship between the MCS and the extension amount of the first CP shown in Table 2 and Table 3 should not be understood as a limitation on the embodiment of the present application.

[0192] In this example, the network device configures a mapping relationship between the MCS or modulation mode or code rate and the extension amount of the first CP or the length of the first CP, so that the terminal device determines the length of the first CP based on the mapping relationship and the MCS or modulation mode or code rate corresponding to the first time slot to meet the EVM requirements and ensure the accuracy of demodulation.

[0193] As another example, the network device configures the length of the first CP or the extension amount of the first CP by using a reference MCS, a reference modulation mode, or a reference code rate. For example, the network device may indicate the length or extension amount of the first symbol CP corresponding to the reference MCS, the reference modulation mode, or the reference code rate through first indication information. The terminal device adaptively adjusts the length of the first CP based on the length of the CP corresponding to the reference MCS, the reference modulation mode, or the reference code rate. For example, when the MCS corresponding to the first time slot is greater than the reference MCS, the length of the first CP is greater than the length of the first symbol CP corresponding to the reference MCS. For another example, when the MCS corresponding to the first time slot is less than the reference MCS, the length of the first CP is less than the length of the first symbol CP corresponding to the reference MCS. For another example, when the modulation order of the modulation mode corresponding to the first time slot is less than the modulation order of the reference modulation mode, the length of the first CP is less than the length of the first symbol CP corresponding to the reference modulation mode. For another example, when the code rate corresponding to the first time slot is less than the reference code rate, the length of the first CP is less than the length of the first symbol CP corresponding to the reference code rate.

[0194] For example, as shown in Table 4, the reference MCS configured for the network device is m1. In configuration 1, the range of values ​​for the extension of the first symbol CP corresponding to the reference MCS is (a1, b1). When the MCS corresponding to the first time slot is less than m1, the range of values ​​for the extension of the first CP is (y1, z1), where y1 is less than a1 and z1 is less than b1.

[0195] Table 4

[0196] In some possible implementations, the reference MCS in Table 4 may also be replaced by the code rate corresponding to the reference MCS.

[0197] As shown in Table 5, the reference modulation scheme configured for the network device is QPSK. In configuration 1, the range of values ​​for the extension of the first CP symbol corresponding to QPSK is (e2, f2). When the modulation order of the modulation scheme corresponding to the first time slot is smaller than QPSK, the range of values ​​for the extension of the first CP symbol is (y2, z2), where y2 is less than e2 and z2 is less than f2.

[0198] Table 5

[0199] In this example, the network device can configure a mapping relationship between the reference MCS or the reference modulation mode and the extension amount of the first CP, so that the terminal device can adaptively adjust the extension amount of the first CP or the length of the first CP by comparing the reference MCS and the MCS corresponding to the first time slot to meet the EVM requirements and ensure the accuracy of demodulation.

[0200] It can be understood that the value range of the extension amount in Table 2, Table 3, Table 4, and Table 5 can also be replaced by a specific value of the extension amount, and the extension amount of the first CP can also be replaced by the length of the first CP. The extension amount of the first CP or the length of the first CP can be represented by the corresponding number of modulation symbols or the number of sampling points. The mapping relationship between the modulation mode or MCS and the extension amount of the CP shown in Table 2, Table 3, Table 4, and Table 5 is only an example, and the mapping relationship shown in Table 2, Table 3, Table 4, and Table 5 should not be understood as a limitation to this application.

[0201] 1202. The terminal device generates a first time slot.

[0202] It is understandable that the specific implementation of step 1202 can refer to the specific implementation of step 901 in Figure 9, which will not be described in detail here.

[0203] In a possible implementation, the method shown in FIG12 further includes step 1203 .

[0204] 1203. The network device sends second indication information, and correspondingly, the terminal device receives the second indication information.

[0205] Exemplarily, the first time slot is included in the first subframe, and the network device can indicate the time for the terminal device to send the first subframe through the second indication information to ensure uplink timing synchronization between the terminal device and the network device. For example, the first time slot is the first time slot in the first subframe. The second indication information includes at least one of the following: a first TA, a starting time of the first CP, and a second difference. Among them, the first TA is used to indicate the advance time of the starting time of the first subframe compared to the arrival time of the downlink subframe, the second difference is the difference between the starting time of the first CP and the starting time of the sixth symbol component in the first OFDM symbol, the ending position of the sixth symbol component is the ending position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP. The first TA is used to indicate the TA corresponding to the first subframe after the first CP is extended. The length of the sixth symbol component is equal to the length before the first CP is extended. The starting time of the sixth symbol component can be understood as the starting time of the CP before the first CP is extended, so the starting time of the first CP can be indicated by indicating the second difference. The index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of , the length of the sixth symbol component is greater than the length of the second CP, and the difference between the length of the sixth symbol component and the length of the second CP is 16κ. The index of the first OFDM symbol in the first subframe is not 0 or 7*2 μ In this case, the length of the sixth symbol component is equal to the length of the second CP.

[0206] Exemplarily, the second indication information is carried in any one of the following items: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, physical downlink shared channel PDSCH.

[0207] Exemplarily, when the second indication information indicates the first TA, the second indication information includes at least one of the following information of the first TA: the number of sampling points corresponding to the first TA, the number of modulation symbols corresponding to the first TA, the duration corresponding to the first TA, the number of unit times N corresponding to the first TA TA About the N TA The corresponding relationship with the first TA can refer to formula (3). The first TA is determined by the first difference or the length of the first CP, and the first difference is the difference between the length of the first CP and the length of the second CP. Alternatively, the first TA is determined by the length of the first CP, or the extension of the first CP. The extension of the first CP can be represented by the first difference. For example, the index of the first OFDM symbol in the first subframe is not 0 or 7*2 μ In the case of , the extension amount of the first CP is equal to the first difference. The index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In this case, the extension amount of the first CP is equal to the difference between the first difference and 16κ.

[0208] As an example, the network device preconfigures multiple TAs and indicates one of the multiple TAs through the second indication information.

[0209] As another example, the network device may determine the first TA according to the length of the first CP or the extension amount of the first CP, and indicate the first TA through the second indication information.

[0210] Exemplarily, the network device may indicate the first TA by configuring the length of the first CP or a mapping relationship between the extension amount of the first CP and the first TA. For example, Table 6 shows a mapping relationship between the extension amount of the first CP and the first TA. As shown in Table 6, when the extension amount of the first CP is (a1, b1), the value range of the first TA is (i1, j1).

[0211] Table 6

[0212] It can be understood that in Table 6, a1 and b1, a2 and b2, i1 and j1, i2 and j2 can be equal to each other or not, that is, the value range of the extension amount of a first CP corresponds to the value range of a first TA or the specific value of the first TA, or the specific value of the extension amount of a first CP can correspond to the value range of a first TA or the specific value of the extension amount of the first CP. The extension amount of the first CP can also be replaced by the length of the first CP. The extension amount of the first CP can be represented by the number of modulation symbols or sampling points corresponding to the extension amount of the first CP, and the length of the first CP can be determined by the number of modulation symbols or sampling points corresponding to the first CP. The first TA can be determined by the number of sampling points, the number of modulation symbols, the duration, and the number of unit time N corresponding to the first TA. TA .

[0213] Exemplarily, the network device can configure the mapping relationship between the extension amount of the first CP and the first TA for the terminal device through the second indication information, or the network device can determine the first TA after the first CP is extended based on the mapping relationship, and indicate the first TA through the second indication information.

[0214] As yet another example, the network device may determine the first TA according to the length of the first CP or the extension amount of the first CP and the first channel.

[0215] Exemplarily, the network device may determine a value range of the first TA based on the length of the first CP or the extension of the first CP and the first channel. The network device may indicate the value range of the first TA through the second indication information, or may determine the value of the first TA from the value range of the first TA and indicate the value of the first TA through the second indication information.

[0216] 1204. The terminal device sends a first time slot, and correspondingly, the network device receives the first time slot.

[0217] Exemplarily, the terminal device may determine the transmission time of the first time slot or the first subframe based on the second indication information.

[0218] 1205. The network device parses the first time slot.

[0219] It is understandable that the specific implementation of step 1204 and step 1205 can refer to the specific implementation of step 902 and step 903 in Figure 9, which will not be described in detail here.

[0220] In an embodiment of the present application, the length of the first CP can be extended, that is, more signals are copied from the end of the first OFDM symbol to the front of the first OFDM symbol, so that the first OFDM symbol transmitted on each transmission path can fall within the corresponding FFT receiving window, thereby reducing signal loss and improving demodulation performance. In addition, when the CP length of the first OFDM symbol changes, the network device can instruct the terminal device to send the first subframe through the second indication information, thereby ensuring uplink timing synchronization between the terminal device and the network device.

[0221] In an embodiment of the present application, information such as the length of the first CP, the extension amount of the first CP, and the first TA may also be specified by the protocol. In this case, the network device does not need to send the first indication information and the second indication information to the terminal device.

[0222] Regarding the starting time of the first subframe, the embodiment of the present application also provides the following examples:

[0223] Example 1: The starting time of the first subframe is the starting time of the sixth symbol component.

[0224] In this example, the first time slot is the first time slot of the first subframe, that is, the first OFDM symbol is the first OFDM symbol of the first subframe. The sixth symbol component is the CP before the first CP extension, and the subframe start time before the first CP extension is used as the subframe start time after the first CP extension. That is, the subframe start time in the CP extension case is the same as the subframe start time in the CP extension case, as shown in Figure 13.

[0225] Exemplarily, before the CP of the first OFDM symbol is extended, the continuous time signal corresponding to the first OFDM symbol is satisfy:

[0226] Where p represents the antenna port, μ represents the subcarrier spacing configuration, and l represents the index of the first OFDM symbol in the first subframe. The value range of l is: represents the number of time slots in the first subframe, represents the number of symbols in the first time slot, Indicates the starting time of the first OFDM symbol, represents the duration of the first OFDM symbol, Indicates the size of the resource grid, Indicates the number of subcarriers per resource block, represents the length of the cyclic prefix, Δf represents, μ0 represents the maximum subcarrier spacing configuration, Indicates the starting index of the resource grid, Indicates the length of the data symbol.

[0227] In the case of CP extension (i.e., CP extension) of the first OFDM symbol 1, the interval before the first OFDM symbol Time continuous signal Satisfies the following formula:

[0228] Where t<0 represents the signal of the previous subframe, T ext Indicates the extension amount of the first CP.

[0229] The starting position of the first OFDM symbol under the subcarrier spacing configuration μ is:

[0230] From the above, it can be seen that when the first OFDM symbol is the first OFDM symbol of the first subframe, the starting time of the first subframe when the first CP is extended is the same as the starting time of the first subframe when the first CP is not extended, that is, t=0 is taken as the subframe starting time.

[0231] In this example, the value range of the first TA includes (TA2-CP1+ΔT, TA2). Among them, CP1 is the length of the first CP, ΔT is the delay spread of the first channel, TA2 is the TA corresponding to the second subframe, the second subframe includes the second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among the multiple OFDM symbols used to carry PUSCH or PDSCH in the second time slot. The second subframe can be understood as the first subframe before the CP of the first OFDM symbol is extended, the third OFDM symbol can be understood as the first OFDM symbol before the first CP is extended, and the second TA can be understood as the TA corresponding to the first subframe before the first CP is extended.

[0232] Exemplarily, when the first TA takes the maximum value, it is necessary to enable the data symbol of the first OFDM symbol on the first transmission path (i.e., the path where the first transmission arrives) to be completely received by the first FFT receiving window. As shown in Figure 14A, the maximum value of the first TA can be equal to the second TA. When the first TA takes the minimum value, it is necessary to enable the data symbol of the first OFDM symbol on the second transmission path (i.e., the path where the last transmission arrives) to be completely received by the first FFT receiving window. As shown in Figure 14B, the minimum value of the first TA can be smaller than the second TA. The minimum value of the first TA can be determined by the delay spread of the first channel and the length of the first CP. For example, the minimum value of the first TA can be TA2-CP1+ΔT.

[0233] Example 2: The starting time of the first subframe is the starting time of the first CP.

[0234] In this example, TA is the difference between the start time of the first subframe and the arrival time of the downlink subframe. As shown in Figure 15, due to the length of the first CP being longer, the start time of the first subframe is moved forward, so the TA after the first CP is extended is greater than the TA before the first CP is extended.

[0235] Exemplarily, the value range of the first TA includes (TA2-CP1+ΔT+ΔD, TA2+ΔD); wherein CP1 is the length of the first CP, ΔT is the delay spread of the first channel, ΔD is the first difference or the extension amount of the first CP, TA2 is the TA corresponding to the second subframe, the second subframe includes the second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol of multiple OFDM symbols in the second time slot used to carry PUSCH or PDSCH. The second subframe can be understood as the first subframe before the CP of the first OFDM symbol is extended, the third OFDM symbol can be understood as the first OFDM symbol before the first CP is extended, and the second TA can be understood as the TA corresponding to the first subframe before the first CP is extended.

[0236] Exemplarily, the CP length of the first OFDM symbol is related to the index of the first OFDM symbol in the first subframe. When the index of the first OFDM symbol in the first subframe is 0, ΔD is (the first difference - 16κ), and when the index of the first OFDM symbol in the first subframe is not 0, ΔD is the first difference.

[0237] For example, as shown in FIG16A , when the first TA is at its maximum value, the data symbol of the first OFDM symbol on the first transmission path must be completely received in the first FFT receive window. The maximum value of the first TA is calculated by adding the extension of the first CP to the second TA. As shown in FIG16B , when the first TA is at its minimum value, the data symbol of the first OFDM symbol on the second transmission path must be completely received in the first FFT receive window. The minimum value of the first TA can be TA2-ΔTA, where TA2 is the second TA and ΔTA is determined by the first CP, delay spread, and the extension of the first CP. For example, ΔTA is CP1-ΔT-ΔD.

[0238] In an embodiment of the present application, the value range of the first TA can be determined based on the second TA, the length of the first CP, the first difference and the delay extension, so that when the first TA takes the maximum value, the data symbol of the first OFDM symbol on the first transmission path (i.e., the path where the first transmission arrives) can just be completely received by the first FFT receiving window, and, when the first TA takes the minimum value, the data symbol of the first OFDM symbol on the second transmission path (i.e., the path where the last transmission arrives) can just be completely received by the first FFT receiving window, thereby ensuring that the first OFDM symbols on multiple transmission paths of the channel can all be completely received by the first FFT receiving window, avoiding signal loss.

[0239] The following describes the device provided in the embodiments of the present application.

[0240] The present application divides the functional modules of the communication device according to the above-mentioned method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated modules 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 this application is schematic and is only a logical function division. There may be other division methods in actual implementation. The communication device of the embodiment of the present application will be described in detail below with reference to Figures 17 to 19.

[0241] Figure 17 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. As shown in Figure 17, the communication device includes a processing unit 1701 and a transceiver unit 1702. The transceiver unit 1702 can implement corresponding communication functions, and the processing unit 1701 is used to process data. For example, the transceiver unit 1702 can also be referred to as a communication interface or a communication unit.

[0242] In some embodiments of the present application, the communication device can be used to execute the actions performed by the first communication device or terminal device in the above method embodiments. In this case, the communication device can be the first communication device or terminal device, or the communication device can be a component that can be configured in the first communication device or terminal device (such as a chip or system, etc.), and the transceiver unit 1702 is used to execute the transceiver-related operations of the first communication device or terminal device in the above method embodiments, and the processing unit 1701 is used to execute the processing-related operations of the first communication device or terminal device in the above method embodiments.

[0243] Exemplarily, the processing unit 1701 generates a first time slot; the transceiver unit 1702 is configured to send the first time slot.

[0244] Optionally, the processing unit 1701 is further configured to determine the length of the first CP based on delay spread.

[0245] Optionally, the transceiver unit 1702 is further used to receive first indication information.

[0246] Optionally, the transceiver unit 1702 is further configured to receive second indication information.

[0247] It can be understood that the specific description of the first time slot, delay extension, first CP, first indication information, second indication information, etc. can be referred to the method embodiment shown above, and will not be described in detail here.

[0248] In other embodiments of the present application, the communication device can be used to execute the actions performed by the second communication device or network device in the above method embodiments. In this case, the communication device can be a second communication device or network device, or the communication device can be or can be configured as a component (such as a chip or system, etc.) of the second communication device or network device, and the transceiver unit 1702 is used to execute the transceiver-related operations of the second communication device or network device in the above method embodiments, and the processing unit 1701 is used to execute the processing-related operations of the second communication device or network device in the above method embodiments.

[0249] Exemplarily, the transceiver unit 1702 is configured to receive a first time slot; and the processing unit 1701 is configured to parse the first time slot.

[0250] Optionally, the transceiver unit 1702 is further used to send first indication information.

[0251] Optionally, the transceiver unit 1702 is further configured to send second indication information.

[0252] It can be understood that the specific description of the first time slot, the first indication information, the second indication information, etc. can be referred to the method embodiment shown above, and will not be described in detail here.

[0253] Optionally, the above-mentioned communication device may further include a storage unit, which may be used to store instructions and / or data. The processing unit 1701 may read the instructions and / or data in the storage unit so that the communication device implements the above-mentioned method embodiment.

[0254] It can be understood that the specific description of the transceiver unit and the processing unit shown in the embodiment of the present application is only an example. For the specific functions or execution steps of the transceiver unit and the processing unit, please refer to the above-mentioned method embodiment and will not be described in detail here.

[0255] The above describes the communication device according to the embodiment of the present application. The following describes possible product forms of the communication device. It should be understood that any product having the functions of the communication device described in FIG. 17 falls within the scope of protection of the embodiment of the present application. It should also be understood that the following description is merely illustrative and does not limit the product forms of the communication device according to the embodiment of the present application to these examples.

[0256] In one possible implementation, in the communication device shown in Figure 17, the processing unit 1701 can be one or more processors, the transceiver unit 1702 can be a transceiver, or the transceiver unit 1702 can also be a sending unit and a receiving unit, the sending unit can be a transmitter, the receiving unit can be a receiver, and the sending unit and the receiving unit are integrated into a single device, such as a transceiver. In the embodiment of the present application, the processor and the transceiver can be coupled, etc., and the embodiment of the present application does not limit the connection method between the processor and the transceiver. During the execution of the above method, the process of sending information in the above method can be understood as the process of the processor outputting the above information. When outputting the above information, the processor outputs the above information to the transceiver so that it can be transmitted by the transceiver. After being output by the processor, the above information may also need to undergo other processing before reaching the transceiver. Similarly, the process of receiving information in the above method can be understood as the process of the processor receiving the input information. When the processor receives the input information, the transceiver receives the above information and inputs it into the processor. Furthermore, after the transceiver receives the above information, the above information may need to be processed further before being received by the processor.

[0257] As shown in FIG. 18 , the communication device 180 includes one or more processors 1820 and a transceiver 1810 .

[0258] In some embodiments of the present application, the communication device can be used to execute the steps or functions performed by the first communication device or terminal equipment in the above method embodiments.

[0259] Exemplarily, the processor 1820 is configured to generate a first time slot; and the transceiver 1810 is configured to send the first time slot.

[0260] Optionally, the transceiver 1810 is further used to receive first indication information.

[0261] Optionally, the transceiver 1810 is further used to receive second indication information.

[0262] Optionally, the processor 1820 is further configured to determine the length of the first CP based on delay spread.

[0263] In other embodiments of the present application, the communication device can be used to execute the steps or functions performed by the second communication device or network equipment in the above method embodiments.

[0264] Exemplarily, the transceiver 1810 is configured to receive a first time slot; and the processor 1820 is configured to parse the first time slot.

[0265] Optionally, the transceiver 1810 is further used to send first indication information.

[0266] Optionally, the transceiver 1810 is further used to send second indication information.

[0267] It will be understood that the specific descriptions of the transceiver and processor shown in the embodiments of the present application are merely examples. For the specific functions or execution steps of the transceiver and processor, reference may be made to the above-mentioned method embodiments, which will not be described in detail here.

[0268] In the above embodiments, the description of the first time slot, delay extension, first CP, first indication information, second indication information, etc. can also refer to the introduction in the above method embodiment, and will not be described in detail here.

[0269] In various implementations of the communication device shown in FIG18 , the transceiver may include a receiver and a transmitter, wherein the receiver is configured to perform a receiving function (or operation) and the transmitter is configured to perform a transmitting function (or operation). The transceiver is configured to communicate with other devices / apparatuses via a transmission medium.

[0270] Optionally, the communication device 180 may further include one or more memories 1830 for storing program instructions and / or data, etc. The memory 1830 is coupled to the processor 1820. The coupling in the embodiment of the present application is an indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. The processor 1820 may operate in conjunction with the memory 1830. The processor 1820 may execute program instructions stored in the memory 1830. Optionally, at least one of the one or more memories may be included in the processor.

[0271] The specific connection medium between the transceiver 1810, processor 1820, and memory 1830 is not limited in the embodiments of the present application. In Figure 18, the memory 1830, processor 1820, and transceiver 1810 are connected via a bus 1840. The bus is represented by a bold line in Figure 18. The connection methods between other components are merely schematic and are not limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, Figure 18 only uses a single bold line, but this does not mean that there is only one bus or only one type of bus.

[0272] In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of the present application may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor, etc.

[0273] In the embodiment of the present application, memory may include but is not limited to non-volatile memories such as hard disk drive (HDD) or solid-state drive (SSD), random access memory (RAM), erasable programmable read-only memory (EPROM), read-only memory (ROM) or portable read-only memory (CD-ROM), etc. Memory is any storage medium that can be used to carry or store program code in the form of instructions or data structures, and can be read and / or written by a computer (such as the communication device shown in the present application), but is not limited thereto. The memory in the embodiment of the present application can also be a circuit or other arbitrarily capable of realizing a storage function, for storing program instructions and / or data.

[0274] Exemplarily, the processor 1820 is primarily used to process communication protocols and communication data, control the entire communication device, execute software programs, and process software program data. The memory 1830 is primarily used to store software programs and data. The transceiver 1810 may include a control circuit and an antenna. The control circuit is primarily used to convert baseband signals into radio frequency signals and process radio frequency signals. The antenna is primarily used to transmit and receive radio frequency signals in the form of electromagnetic waves. Input and output devices, such as a touch screen, display, and keyboard, are primarily used to receive user input and output data to the user.

[0275] When the communication device is powered on, the processor 1820 can read the software program in the memory 1830, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be sent wirelessly, the processor 1820 performs baseband processing on the data to be sent and outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal and then transmits the radio frequency signal to the outside in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 1820. The processor 1820 converts the baseband signal into data and processes the data.

[0276] In another implementation, the RF circuit and antenna may be provided independently of the processor performing baseband processing. For example, in a distributed scenario, the RF circuit and antenna may be remotely arranged independent of the communication device.

[0277] It is understood that the communication device shown in the embodiment of the present application may also have more components than those in Figure 18, and the embodiment of the present application is not limited to this. The method performed by the processor and transceiver shown above is only an example. For the specific steps performed by the processor and transceiver, please refer to the method described above.

[0278] In another possible implementation, in the communication device shown in FIG17 , the processing unit 1701 may be one or more logic circuits, and the transceiver unit 1702 may be an input / output interface, or may be called a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver unit 1702 may also be a sending unit and a receiving unit, the sending unit may be an output interface, the receiving unit may be an input interface, and the sending unit and the receiving unit are integrated into one unit, such as an input / output interface. As shown in FIG19 , the communication device shown in FIG19 includes a logic circuit 1901 and an interface 1902. That is, the above-mentioned processing unit 1701 can be implemented using a logic circuit 1901, and the transceiver unit 1702 can be implemented using an interface 1902. The logic circuit 1901 may be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, etc., and the interface 1902 may be a communication interface, an input / output interface, a pin, etc. For example, FIG19 is illustrated using the above-mentioned communication device as a chip, and the chip includes a logic circuit 1901 and an interface 1902.

[0279] In the embodiment of the present application, the logic circuit and the interface may also be coupled to each other. The embodiment of the present application does not limit the specific connection method between the logic circuit and the interface.

[0280] In some embodiments of the present application, the communication device may be configured to execute the steps or functions performed by the first communication device or terminal device in the method embodiments described above. Exemplarily, logic circuit 1901 is configured to generate a first time slot; interface 1902 is configured to output the first time slot. Optionally, logic circuit 1901 is further configured to determine the length of the first CP. Optionally, interface 1902 is further configured to receive first indication information. Optionally, interface 1902 is further configured to receive second indication information.

[0281] In other embodiments of the present application, the communication device can be used to execute the steps or functions performed by the second communication device or network device in the above method embodiments. Exemplarily, interface 1902 is used to input a first time slot; logic circuit 1901 is used to parse the first time slot. Optionally, interface 1902 is further used to send first indication information. Optionally, interface 1902 is further used to send second indication information.

[0282] It can be understood that the specific description of the logic circuit and interface shown in the embodiments of the present application is only an example. For the specific functions or execution steps of the logic circuit and interface, please refer to the above-mentioned method embodiment and will not be described in detail here.

[0283] In the above embodiments, the description of the first time slot, delay extension, first CP, first indication information, second indication information, etc. can also refer to the introduction in the above method embodiment, and will not be described in detail here.

[0284] It can be understood that the communication device shown in the embodiment of the present application can implement the method provided in the embodiment of the present application in the form of hardware, or can implement the method provided in the embodiment of the present application in the form of software, etc., and the embodiment of the present application is not limited to this.

[0285] An embodiment of the present application further provides a communication system, which includes a first communication device and a second communication device, and the first communication device and the second communication device are used to execute the method in any of the aforementioned embodiments.

[0286] An embodiment of the present application also provides a communication system, which includes a terminal device and a network device, and the terminal device and the network device are used to execute the method in any of the aforementioned embodiments.

[0287] In addition, the present application also provides a computer program, which is used to implement the operations and / or processing performed by the first communication device or terminal equipment in the method provided by the present application.

[0288] The present application also provides a computer program, which is used to implement the operations and / or processing performed by the second communication device or network equipment in the method provided by the present application.

[0289] The present application also provides a computer-readable storage medium, which stores computer code. When the computer code runs on a computer, it enables the computer to execute the operations and / or processing performed by the first communication device or terminal equipment in the method provided by the present application.

[0290] The present application also provides a computer-readable storage medium, which stores computer code. When the computer code runs on a computer, it enables the computer to execute the operations and / or processing performed by the second communication device or network equipment in the method provided by the present application.

[0291] The present application also provides a computer program product, which includes computer code or computer program. When the computer code or computer program runs on a computer, the operations and / or processing performed by the first communication device or terminal equipment in the method provided by the present application are executed.

[0292] The present application also provides a computer program product, which includes computer code or computer program. When the computer code or computer program runs on a computer, the operations and / or processing performed by the second communication device or network device in the method provided by the present application are executed.

[0293] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or can be electrical, mechanical or other forms of connection.

[0294] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of the present application.

[0295] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0296] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned readable storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0297] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A symbol processing method, characterized in that: Applied to a first communication device, comprising: Generate a first time slot, the first time slot includes a plurality of orthogonal frequency division multiplexing OFDM symbols, the plurality of OFDM symbols include a first OFDM symbol and a second OFDM symbol, the first OFDM symbol is the first OFDM symbol of the plurality of OFDM symbols, the first OFDM symbol includes a first cyclic prefix CP, the second OFDM symbol includes a second CP, the length of the first CP is greater than the length of the second CP, the length of the first CP is greater than a first value, and the first value corresponds to a subcarrier spacing; The first time slot is transmitted.

2. The method according to claim 1, characterized in that The first communication device is a network device, and the method further includes: The length of the first CP is determined based on a delay spread of a first channel, where the delay spread is a difference in transmission delays of the first time slot in a first transmission path and a second transmission path of the first channel, and the first channel carries the first time slot.

3. The method according to claim 1, characterized in that The first communication device is a terminal device, and the method further includes: First indication information is received, where the first indication information indicates a length of the first CP.

4. The method according to claim 3, characterized in that The first indication information is carried in any one of the following items: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, and physical downlink shared channel PDSCH.

5. The method according to claim 1, 3 or 4, characterized in that: The first communication device is a terminal device, the first time slot is included in a first subframe, and the method further includes: Receive second indication information, where the second indication information includes at least one of the following: a first timing advance TA, a start time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the start time of the first subframe compared to the arrival time of the downlink subframe, and the second difference is the difference between the start time of the first CP and the start time of the sixth symbol component in the first OFDM symbol, the end position of the sixth symbol component is the end position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP; The sending the first time slot includes: The first subframe is sent based on the second indication information.

6. A symbol processing method, characterized in that: Applied to a second communication device, comprising: Receive a first time slot, the first time slot includes a plurality of orthogonal frequency division multiplexing OFDM symbols, the plurality of OFDM symbols include a first OFDM symbol and a second OFDM symbol, the first OFDM symbol is the first OFDM symbol of the plurality of OFDM symbols, the first OFDM symbol includes a first cyclic prefix CP, the second OFDM symbol includes a second CP, the length of the first CP is greater than the length of the second CP, the length of the first CP is greater than a first value, and the first value corresponds to a subcarrier spacing; The first time slot is parsed.

7. The method according to claim 6, characterized in that The second communication device is a network device, the first time slot is included in a first subframe, and the method further includes: Send second indication information, the second indication information including at least one of the following: a first timing advance TA, a start time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the start time of the first subframe compared to the arrival time of the downlink subframe, the second difference is the difference between the start time of the first CP and the start time of the sixth symbol component in the first OFDM symbol, the end position of the sixth symbol component is the end position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP.

8. The method according to claim 5 or 7, characterized in that: The second indication information includes the first TA, where the first TA is determined by a first difference or a length of the first CP, and the first difference is a difference between a length of the first CP and a length of the second CP.

9. The method according to claim 5, 7 or 8, characterized in that: The starting time of the first subframe is the starting time of the sixth symbol component.

10. The method according to claim 9, characterized in that The value range of the first TA includes (TA2-CP1+ΔT, TA2); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot for carrying PUSCH or PDSCH.

11. The method according to claim 5, 7 or 8, characterized in that The starting time of the first subframe is the starting time of the first CP.

12. The method according to claim 11, characterized in that The value range of the first TA includes (TA2-CP1+ΔT+ΔD, TA2+ΔD); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the ΔD is the first difference, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot for carrying PUSCH or PDSCH.

13. The method according to any one of claims 5, 7-12, characterized in that: The second indication information includes at least one of the following information of the first TA: the number of sampling points corresponding to the first TA, the number of modulation symbols corresponding to the first TA, the duration corresponding to the first TA, and the number of unit times corresponding to the first TA.

14. The method according to any one of claims 5, 7 to 13, characterized in that: The second indication information is carried in any one of the following items: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, and physical downlink shared channel PDSCH.

15. The method according to any one of claims 1 to 14, characterized in that: The index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of -μ +16β); or, The index of the first OFDM symbol in the first subframe is not equal to 0 or 7*2 μ In the case where the first value is equal to 144β*2 -μ ; The first subframe includes the first time slot, the β corresponds to the maximum number of subcarriers and the maximum subcarrier spacing of the transmission bandwidth, and the μ corresponds to the subcarrier spacing configuration.

16. The method according to any one of claims 1 to 15, characterized in that: The length of the first CP corresponds to a delay spread of a first channel, where the delay spread is a difference in transmission delays of the first time slot in a first transmission path and a second transmission path of the first channel, and the first channel carries the first time slot.

17. The method according to claim 16, characterized in that The first transmission path is a transmission path that arrives first among multiple transmission paths of the first channel, and the second transmission path is a transmission path that arrives last among the multiple transmission paths.

18. The method according to claim 16 or 17, wherein the length of the first CP is greater than or equal to the delay spread.

19. The method according to any one of claims 16 to 18, characterized in that: The length of the first CP is determined by the delay spread and at least one of the modulation and coding strategy MCS, the modulation mode, and the code rate.

20. The method according to claim 19, characterized in that The length of the first CP is positively correlated with the MCS; or, The length of the first CP is positively correlated with the modulation order corresponding to the modulation mode; or, The length of the first CP is positively correlated with the code rate.

21. The method according to any one of claims 1 to 20, characterized in that: The multiple OFDM symbols are used to carry a physical downlink shared channel PDSCH or a physical uplink shared channel PUSCH.

22. The method according to any one of claims 1 to 21, characterized in that: The end position of the first OFDM symbol is the same as the starting position of the second OFDM symbol, and the first symbol component in the first OFDM symbol is the same as the second symbol component in the second OFDM symbol, wherein the end position of the first symbol component is the end position of the first OFDM symbol, the second symbol component is located before the third symbol component in the second OFDM symbol, the end position of the third symbol component is the same as the end position of the second OFDM symbol, the length of the third symbol component is less than or equal to the length of the second CP, and the second CP is obtained by the third symbol component.

23. The method according to claim 22, characterized in that The fourth symbol component in the first OFDM symbol is the same as the fifth symbol component in the second OFDM symbol, the starting position of the fourth symbol component is the same as the ending position of the first CP, the ending position of the second symbol component is the same as the starting position of the fifth symbol component, the ending position of the fifth symbol component is the same as the starting position of the third symbol component, and the sum of the lengths of the fifth symbol component and the third symbol component is equal to the length of the second CP.

24. A communication device, characterized in that: include: a processing unit, configured to generate a first time slot, the first time slot comprising a plurality of orthogonal frequency division multiplexing OFDM symbols, the plurality of OFDM symbols comprising a first OFDM symbol and a second OFDM symbol, the first OFDM symbol being the first OFDM symbol of the plurality of OFDM symbols, the first OFDM symbol comprising a first cyclic prefix CP, the second OFDM symbol comprising a second CP, the length of the first CP being greater than the length of the second CP, the length of the first CP being greater than a first value, and the first value corresponding to a subcarrier spacing; The transceiver unit sends the first time slot.

25. The device according to claim 24, characterized in that The processing unit is further used to determine the length of the first CP based on the delay extension of the first channel, where the delay extension is the difference in transmission delay of the first time slot in the first transmission path and the second transmission path of the first channel, and the first channel carries the first time slot.

26. The device according to claim 24, characterized in that The transceiver unit is further used to receive first indication information, where the first indication information indicates the length of the first CP.

27. The device according to claim 26, characterized in that The first indication information is carried in any one of the following items: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, and physical downlink shared channel PDSCH.

28. The device according to claim 24, 26 or 27, characterized in that The first time slot is included in the first subframe, and the transceiver unit is further used to receive second indication information, wherein the second indication information includes at least one of the following: a first timing advance TA, a start time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the start time of the first subframe compared to the arrival time of the downlink subframe, and the second difference is the difference between the start time of the first CP and the start time of the sixth symbol component in the first OFDM symbol, the end position of the sixth symbol component is the end position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP; The processing unit is further configured to send the first subframe through the transceiver unit based on the second indication information.

29. A communication device, characterized in that: include: A transceiver unit, configured to receive a first time slot, the first time slot comprising a plurality of orthogonal frequency division multiplexing OFDM symbols, the plurality of OFDM symbols comprising a first OFDM symbol and a second OFDM symbol, the first OFDM symbol being the first OFDM symbol of the plurality of OFDM symbols, the first OFDM symbol comprising a first cyclic prefix CP, the second OFDM symbol comprising a second CP, the length of the first CP being greater than the length of the second CP, the length of the first CP being greater than a first value, and the first value corresponding to a subcarrier spacing; A processing unit is used to parse the first time slot.

30. The device according to claim 29, characterized in that The first time slot is included in the first subframe, and the transceiver unit is further used to send second indication information, wherein the second indication information includes at least one of the following: a first timing advance TA, a starting time of the first CP, and a second difference, wherein the first TA is used to indicate the advance time of the starting time of the first subframe compared to the arrival time of the downlink subframe, and the second difference is the difference between the starting time of the first CP and the starting time of the sixth symbol component in the first OFDM symbol, the ending position of the sixth symbol component is the ending position of the first CP, and the length of the sixth symbol component is greater than or equal to the length of the second CP.

31. The device according to claim 28 or 30, characterized in that The second indication information includes the first TA, where the first TA is determined by a first difference or a length of the first CP, and the first difference is a difference between a length of the first CP and a length of the second CP.

32. The device according to claim 28, 30 or 31, characterized in that The starting time of the first subframe is the starting time of the sixth symbol component.

33. The device according to claim 32, characterized in that The value range of the first TA includes (TA2-CP1+ΔT, TA2); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot for carrying PUSCH or PDSCH.

34. The device according to claim 28, 30 or 31, characterized in that The starting time of the first subframe is the starting time of the first CP.

35. The device according to claim 34, characterized in that The value range of the first TA includes (TA2-CP1+ΔT+ΔD, TA2+ΔD); wherein the CP1 is the length of the first CP, the ΔT is the delay extension of the first channel carrying the first subframe, the ΔD is the first difference, the TA2 is the TA corresponding to the second subframe, the second subframe includes a second time slot, the CP length of the third OFDM symbol in the second time slot is less than the length of the first CP, and the CP length of the third OFDM symbol is greater than or equal to the length of the CP of other OFDM symbols in the second time slot, and the third OFDM symbol is the first OFDM symbol among multiple OFDM symbols in the second time slot for carrying PUSCH or PDSCH.

36. The device according to any one of claims 28, 30-35, characterized in that The second indication information includes at least one of the following information of the first TA: the number of sampling points corresponding to the first TA, the number of modulation symbols corresponding to the first TA, the duration corresponding to the first TA, and the number of unit times corresponding to the first TA.

37. The device according to any one of claims 28, 30-36, characterized in that The second indication information is carried in any one of the following items: downlink control information, radio resource control signaling, media access control MAC control element CE, system message SIB, and physical downlink shared channel PDSCH.

38. The device according to any one of claims 24 to 37, characterized in that The index of the first OFDM symbol in the first subframe is 0 or 7*2 μ In the case of -μ +16β); or, The index of the first OFDM symbol in the first subframe is not equal to 0 or 7*2 μ In the case where the first value is equal to 144β*2 -μ ; The first subframe includes the first time slot, the β corresponds to the maximum number of subcarriers and the maximum subcarrier spacing of the transmission bandwidth, and the μ corresponds to the subcarrier spacing configuration.

39. The device according to any one of claims 24 to 38, characterized in that The length of the first CP corresponds to a delay spread of a first channel, where the delay spread is a difference in transmission delays of the first time slot in a first transmission path and a second transmission path of the first channel, and the first channel carries the first time slot.

40. The device according to claim 39, characterized in that The first transmission path is a transmission path that arrives first among multiple transmission paths of the first channel, and the second transmission path is a transmission path that arrives last among the multiple transmission paths.

41. The device according to claim 39 or 40, characterized in that The length of the first CP is greater than or equal to the delay spread.

42. The device according to any one of claims 39 to 41, characterized in that The length of the first CP is determined by the delay spread and at least one of the modulation and coding strategy MCS, the modulation mode, and the code rate.

43. The device according to claim 42, characterized in that The length of the first CP is positively correlated with the MCS; or, The length of the first CP is positively correlated with the modulation order corresponding to the modulation mode; or, The length of the first CP is positively correlated with the code rate.

44. The device according to any one of claims 24 to 43, characterized in that The multiple OFDM symbols are used to carry a physical downlink shared channel PDSCH or a physical uplink shared channel PUSCH.

45. The device according to any one of claims 24 to 44, characterized in that The end position of the first OFDM symbol is the same as the starting position of the second OFDM symbol, and the first symbol component in the first OFDM symbol is the same as the second symbol component in the second OFDM symbol, wherein the end position of the first symbol component is the end position of the first OFDM symbol, the second symbol component is located before the third symbol component in the second OFDM symbol, the end position of the third symbol component is the same as the end position of the second OFDM symbol, the length of the third symbol component is less than or equal to the length of the second CP, and the second CP is obtained by the third symbol component.

46. ​​The device according to claim 45, characterized in that The fourth symbol component in the first OFDM symbol is the same as the fifth symbol component in the second OFDM symbol, the starting position of the fourth symbol component is the same as the ending position of the first CP, the ending position of the second symbol component is the same as the starting position of the fifth symbol component, the ending position of the fifth symbol component is the same as the starting position of the third symbol component, and the sum of the lengths of the fifth symbol component and the third symbol component is equal to the length of the second CP.

47. A communication device, characterized in that: including a processor and a memory; The memory is used to store instructions; The processor is configured to execute the instructions so that the method according to any one of claims 1 to 23 is performed.

48. A communication device, characterized in that: comprising a logic circuit and an interface, wherein the logic circuit and the interface are coupled; The interface is used to input and / or output code instructions, and the logic circuit is used to execute the code instructions so that the method described in any one of claims 1 to 23 is executed.

49. A computer-readable storage medium, characterized in that The computer-readable storage medium is used to store a computer program. When the computer program is executed, the method according to any one of claims 1 to 23 is executed.

50. A computer program, characterized in that When the computer program is executed, the method according to any one of claims 1 to 23 is performed.

51. A communication system, characterized in that: The communication system comprises a first communication device and a second communication device, wherein the first communication device is used to execute the method according to any one of claims 1-5 and 8-23, and the second communication device is used to execute the method according to any one of claims 6-23.

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