Communication method and apparatus

Abstract

The present application relates to a communication method and apparatus. The method comprises: a terminal apparatus receiving a first signal and performing a fast Fourier transform on the first signal, so as to obtain a second signal, wherein the second signal comprises a frequency-domain modulation symbol; the terminal apparatus performing a discrete Fourier transform on the second signal, so as to obtain a third signal, wherein the third signal comprises a time-domain modulation symbol; and the terminal apparatus obtaining a fourth signal from the third signal. In the embodiments of the present application, single-carrier OFDM can be used in downlink transmission, thereby reducing the PAPR of the downlink transmission and improving the performance or power efficiency of downlink transmission. Moreover, in the embodiments of the present application, a signal sending end performs a discrete Fourier transform in a unified manner on signals of multiple users or multiple channels, such that after an inverse fast Fourier transform is performed on the signals which have been subjected to a discrete Fourier transform, the probability of mutual superimposition of signals of different users or different channels is reduced, thereby further reducing the PAPR.

Description

Communication method and device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on January 4, 2024, with application number 202410027556.3 and application name "A Communication Method and Device", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0004] In fourth-generation (4G) and fifth-generation (5G) communication systems, uplink transmission primarily utilizes a discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM) waveform, commonly known as single-carrier orthogonal frequency division multiplexing (OFDM). Compared to traditional OFDM waveforms, DFT-s-OFDM adds a discrete Fourier transform (DFT) process at the transmitter, resulting in a lower peak-to-average power ratio (PAPR) for the signal, thereby improving the performance or power efficiency of user equipment (UE).

[0005] For downlink transmission, the traditional OFDM waveform is still used. This waveform is well-suited to technologies such as multi-channel digital precoding and multi-stream transmission. However, the PAPR of this waveform is relatively high, which reduces the performance and power efficiency of downlink transmission.

[0006] Summary of the Invention

[0007] Embodiments of the present application provide a communication method and apparatus for introducing single-carrier OFDM in the downlink to improve downlink transmission performance or power efficiency.

[0008] In a first aspect, a communication method is provided, which can be performed by a terminal device. The terminal device is, for example, a terminal device, or other device including the functions of a terminal device, or a chip system (or chip) or other functional module, which can realize the functions of the terminal device, and the chip system or functional module is, for example, set in the terminal device. The method includes: receiving a first signal; performing a fast Fourier transform on the first signal to obtain a second signal, the second signal including frequency domain modulation symbols; performing an inverse discrete Fourier transform on the second signal to obtain a third signal, the third signal including time domain modulation symbols; and obtaining a fourth signal from the third signal.

[0009] The embodiments of the present application can use single-carrier OFDM in downlink transmission, thereby reducing the PAPR of downlink transmission and improving the performance or power efficiency of downlink transmission. The embodiments of the present application take into account that downlink transmission may involve a network device sending signals to multiple users simultaneously, or a network device sending signals on multiple channels. Therefore, the embodiments of the present application can also implement simultaneous transmission of multi-user or multi-channel signals. For example, the third signal may include multiple signals. When implementing simultaneous transmission of multi-user or multi-channel signals, the embodiments of the present application do not need to time-share the signals of different users or different channels, thereby reducing signal transmission delay. Moreover, the signal transmitter can perform a unified discrete Fourier transform on the multi-user or multi-channel signals, rather than performing a separate discrete Fourier transform on the signals of different users or different channels. The corresponding signal receiver can then perform a unified inverse discrete Fourier transform on the received signals. If the signal transmitter performs a separate discrete Fourier transform on the signals of different users or different channels, then after performing an inverse fast Fourier transform on the discrete Fourier transformed signals, the signals of different users or different channels may overlap, resulting in an increase in the PAPR. In the embodiment of the present application, the signal transmitting end uniformly performs discrete Fourier transform on the signals of multiple users or multiple channels. After the discrete Fourier transformed signals are subjected to inverse fast Fourier transform, the probability of superposition of signals of different users or different channels is reduced, thereby further reducing the PAPR.

[0010] In an optional embodiment, obtaining the fourth signal from the third signal includes: obtaining the fourth signal from the third signal according to first indication information, wherein the first indication information is used to indicate a resource location within a time unit of a time domain modulation symbol included in the fourth signal. In this embodiment of the present application, the network device may indicate the location of the fourth signal in the third signal, so that the terminal device can more accurately obtain the fourth signal from the third signal.

[0011] In an optional embodiment, the first indication information is used to indicate the resource location of the time domain modulation symbol included in the fourth signal within a time unit, including: the first indication information is used to indicate the starting time domain modulation symbol of the fourth signal within the time unit, and the number of time domain modulation symbols of the fourth signal within the time unit. Alternatively, the first indication information may also indicate the ending time domain modulation symbol of the fourth signal within a time unit, and the number of time domain modulation symbols included in the fourth signal within a time unit, etc., and there is no restriction on the indication content. Among them, the starting time domain modulation symbol of the fourth signal within a time unit refers to the first time domain modulation symbol included in the fourth signal within the time unit; the ending time domain modulation symbol of the fourth signal within a time unit refers to the last time domain modulation symbol included in the fourth signal within the time unit. The "first time domain modulation symbol" and "last time domain modulation symbol" here are described in chronological order.

[0012] In an optional embodiment, the method further includes: determining, based on the second indication information, the time domain resources and frequency domain resources occupied by the third signal. The second indication information enables the terminal device to receive the third signal. For example, in this embodiment of the present application, the network device may indicate the third signal so that the terminal device can receive the third signal.

[0013] In an optional embodiment, the method further includes: receiving first information, the first information being used to schedule the fourth signal, wherein the first information includes first indication information, the first indication information being used to indicate the resource position of the time domain modulation symbol included in the fourth signal within a time unit. The first indication information may come from a network device. For example, before the UE receives the first signal, or before the network device sends the first signal, the network device may send first information to the UE, the first information may schedule the fourth signal, and the first indication information may be included in the first information. The first information is, for example, included in the PDCCH, for example, the first information is DCI; or, the first information may also be included in the RRC signaling; or, the first information may also be included in the signaling of other protocol layers, such as MAC CE, etc., without limitation.

[0014] In an optional embodiment, the first information further includes third indication information, where the third indication information is used to indicate a modulation and coding scheme of the fourth signal. The terminal device needs to use the modulation and coding scheme of the fourth signal to demodulate the fourth signal. The network device may indicate the modulation and coding scheme of the fourth signal through the third indication information, enabling the terminal device to demodulate the fourth signal.

[0015] In an optional embodiment, the method further includes: determining a transport block size corresponding to the fourth signal based on the first indication information and the third indication information. In this embodiment of the present application, the terminal device may only need to receive the fourth signal in the third signal. Therefore, the terminal device can determine the transport block size corresponding to the fourth signal based on the first indication information, rather than determining the transport block size corresponding to the fourth signal based on the time domain resource indication information included in the second indication information, so that the terminal device can correctly receive the fourth signal.

[0016] In an optional embodiment, obtaining the fourth signal from the third signal includes: determining at least one candidate control channel from the time domain modulation symbols included in the third signal, each candidate control channel including L control channel units, each control channel unit including at least one time domain modulation symbol, where L is a positive integer; detecting the at least one candidate control channel. For example, if the fourth signal is a control channel, the terminal device can obtain the fourth signal by detection, and the detection process is, for example, blind detection. The candidate control channels in the embodiment of the present application include time domain modulation symbols, and the fourth signal also includes time domain modulation symbols, thereby enabling the terminal device to detect the fourth signal.

[0017] In an optional embodiment, determining at least one candidate control channel from the time-domain modulation symbols included in the third signal includes: determining a starting control channel element from the time-domain modulation symbols included in the third signal; and determining the at least one candidate control channel based on the starting control channel element and a number of detections of the candidate control channels. The terminal device may perform detection based on the starting control channel element and the number of detections of the candidate control channels, thereby determining the at least one candidate control channel.

[0018] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, and the fourth signal and the fifth signal are time-division multiplexed within one OFDM symbol. In this embodiment of the present application, different signals can be time-division multiplexed within one OFDM symbol, reducing the granularity of time-division multiplexing and improving the utilization of time domain resources.

[0019] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, the fourth signal is carried on the first channel, and the fifth signal is carried on the second channel. The fourth signal and the fifth signal can be carried on the same channel or on different channels, without limitation. In addition, the target receiving ends of the fourth signal and the fifth signal can be the same terminal device or different terminal devices. In other words, the embodiment of the present application can transmit multi-user and / or multi-channel signals and can reduce PAPR.

[0020] In an optional embodiment, the first channel is a physical downlink control channel, the second channel is a physical downlink shared channel, and the first channel is used to schedule the second channel; or, both the first channel and the second channel are physical downlink control channels; or, both the first channel and the second channel are downlink common channels. These are merely examples, and the embodiments of the present application do not limit the implementation of the first channel and the second channel.

[0021] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, and the method further includes: receiving a demodulation reference signal, wherein the demodulation reference signal is used for channel estimation of the fourth signal and the fifth signal, and / or the demodulation reference signal occupies different time units from the fourth signal and / or the fifth signal. In this embodiment of the present application, multiple signals can share a demodulation reference signal, which is beneficial to reducing the number of demodulation reference signals, saving transmission overhead, and allowing more resources to be used to transmit other signals.

[0022] In an optional embodiment, the method further includes: receiving a demodulation reference signal and power ratio indication information, wherein the demodulation reference signal and the fourth signal occupy different time units, the demodulation reference signal is used for channel estimation of the fourth signal, and the power ratio indication information is used to indicate the power ratio of the demodulation reference signal to the fourth signal, the power ratio being less than or equal to 1; and demodulating the fourth signal according to the channel estimation result and the power ratio. In this embodiment of the present application, the network device may also send demodulation reference signals separately for different signals, and the network device may send multiple demodulation reference signals. If the network device sends multiple demodulation reference signals, the multiple demodulation reference signals may be code division multiplexed, for example, the multiple demodulation reference signals may be superimposed in the time domain and / or frequency domain; and the signals corresponding to the multiple demodulation reference signals may not be superimposed in the time domain. In this case, the received power spectral density of one of the multiple demodulation reference signals may actually be lower than the received power corresponding to the signal using the demodulation reference signal for channel estimation. Therefore, in order to improve the demodulation accuracy, in an embodiment of the present application, when the terminal device demodulates the fourth signal, in addition to referring to the channel estimation result obtained according to the demodulation reference signal corresponding to the fourth signal, it can also refer to the power ratio indication information, so that the demodulation of the fourth signal is more accurate.

[0023] In an optional embodiment, the method also includes: determining a first modulation order and a second modulation order, wherein the first modulation order is the modulation order included in the modulation coding scheme corresponding to the fourth signal, and the second modulation order is higher than the first modulation order; and demodulating the fourth signal according to some constellation points in the constellation diagram corresponding to the second modulation order.

[0024] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, and the method further includes: determining a first modulation order and a second modulation order, the first modulation order being the modulation order included in the modulation and coding scheme corresponding to the fourth signal, the second modulation order being the modulation order included in the modulation and coding scheme corresponding to the fifth signal, and the second modulation order being higher than the first modulation order; demodulating the fourth signal according to some constellation points in the constellation diagram corresponding to the second modulation order; and demodulating the fifth signal according to all constellation points in the constellation diagram corresponding to the second modulation order.

[0025] When a terminal device receives multiple signals (for example, the third signal includes the fourth signal and the fifth signal), the modulation orders corresponding to different signals are the same or different. When the modulation orders corresponding to different signals are different, the terminal device can demodulate all signals according to the higher-order modulation order. When the network device modulates the fourth signal according to the second modulation order, the information bits carried by the modulation symbol remain unchanged. For example, the first modulation order is QPSK, and each modulation symbol obtained by QPSK modulation can carry 2 information bits; the second modulation order is 16QAM, and the modulation symbol obtained by 16QAM modulation should originally carry 4 information bits, but when the network device uses 16QAM to modulate the fourth signal, each modulation symbol still carries 2 information bits instead of 4 information bits. For the constellation diagram corresponding to the second modulation order, the network device may only use some of the constellation points in the constellation diagram when modulating the fourth signal, instead of all the constellation points in the constellation diagram (while the network device will normally use all the constellation points in the constellation diagram when modulating the fifth signal). Therefore, when demodulating the fourth signal, the terminal device also uses some of the constellation points in the constellation diagram, rather than all of the constellation points in the constellation diagram. For example, the Euclidean distance between the constellation points used to demodulate the fourth signal can be greater, thereby improving demodulation performance.

[0026] In an optional embodiment, performing an inverse discrete Fourier transform on the second signal to obtain the third signal includes: performing the inverse discrete Fourier transform on information of the second signal in each of M time units to obtain the third signal, where the M time units are time units occupied by the first signal, and M is a positive integer. The terminal device may perform the inverse discrete Fourier transform processing on each of the M time units, so that the third signal includes the processing results for each of the M time units.

[0027] In a second aspect, another communication method is provided, which can be performed by a network device. The network device is, for example, a network device, or other device including the functions of a network device, or a chip system (or, chip) or other functional module, which can realize the functions of the network device, and the chip system or functional module is, for example, set in the network device. Optionally, the network device is an access network device. Optionally, the access network device is, for example, a base station, or other device in the access network. The method includes: performing a discrete Fourier transform on a third signal to obtain a second signal, the second signal including frequency domain modulation symbols, the third signal including a fourth signal, and the fourth signal including time domain modulation symbols; performing an inverse fast Fourier transform on the second signal to obtain a first signal; and sending the first signal.

[0028] In an optional embodiment, the method further includes: sending first information, the first information being used to schedule the fourth signal, wherein the first information includes first indication information, the first indication information being used to indicate the resource position of the time domain modulation symbol included in the fourth signal within a time unit.

[0029] In an optional embodiment, the first indication information is used to indicate the resource position of the time domain modulation symbol included in the fourth signal within a time unit, including: the first indication information is used to indicate the starting time domain modulation symbol of the fourth signal within the time unit, and indicates the number of time domain modulation symbols of the fourth signal within the time unit.

[0030] In an optional implementation, the first information further includes second indication information, where the second indication information is used to indicate the time domain resources and frequency domain resources occupied by the third signal.

[0031] In an optional embodiment, the first information further includes third indication information, where the third indication information is used to indicate a modulation and coding scheme of the fourth signal, and the first indication information and the third indication information are used to determine a transmission block size corresponding to the fourth signal.

[0032] In an optional embodiment, before performing an inverse fast Fourier transform on the second signal, the method further includes: determining at least one candidate control channel from the time domain modulation symbols included in the third signal, each candidate control channel including L control channel units, each control channel unit including at least one time domain modulation symbol, and L is a positive integer; and determining the fourth signal from the at least one candidate control channel, the fourth signal being a candidate control channel among the at least one candidate control channel.

[0033] In an optional embodiment, determining at least one candidate control channel from the time-domain modulation symbols included in the third signal includes: determining a starting control channel element from the time-domain modulation symbols included in the third signal; and determining the at least one candidate control channel based on the starting control channel element and the number of times the candidate control channels are detected. That is, the network device can also determine the fourth signal from the third signal in a manner similar to that used by the terminal device.

[0034] In an optional implementation, the third signal includes the fourth signal and the fifth signal, and the fourth signal and the fifth signal are time-division multiplexed within one OFDM symbol.

[0035] In an optional implementation, the third signal includes the fourth signal and the fifth signal, wherein the fourth signal is carried on the first channel and the fifth signal is carried on the second channel.

[0036] In an optional embodiment, the first channel is a physical downlink control channel, the second channel is a physical downlink shared channel, and the first channel is used to schedule the second channel; or, the first channel and the second channel are both physical downlink control channels; or, the first channel and the second channel are both downlink common channels.

[0037] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, and the method further includes: sending a demodulation reference signal, the demodulation reference signal is used for channel estimation of the fourth signal and the fifth signal, and / or the demodulation reference signal occupies different time units from the fourth signal and / or the fifth signal.

[0038] In an optional embodiment, the method further includes: sending a demodulation reference signal and power ratio indication information, the demodulation reference signal and the fourth signal occupy different time units, the demodulation reference signal is used for channel estimation of the fourth signal, and the power ratio indication information is used to indicate the power ratio of the demodulation reference signal to the fourth signal, and the power ratio is less than or equal to 1.

[0039] In an optional embodiment, the method also includes: determining a first modulation order and a second modulation order, wherein the first modulation order is the modulation order included in the modulation coding scheme corresponding to the fourth signal, and the second modulation order is higher than the first modulation order; and constellation modulating the fourth signal according to some constellation points in the constellation diagram corresponding to the second modulation order.

[0040] In an optional embodiment, the third signal includes the fourth signal and the fifth signal, the second modulation order is the modulation order included in the modulation coding scheme corresponding to the fifth signal, and the method further includes: constellation modulating the fifth signal according to all constellation points in the constellation diagram corresponding to the second modulation order.

[0041] In an optional embodiment, performing a discrete Fourier transform on the third signal to obtain a second signal includes: performing the discrete Fourier transform on information of the third signal in each of M time units to obtain the second signal, where the M time units are the time units occupied by the first signal, and M is a positive integer.

[0042] Regarding the technical effects brought about by the second aspect or various optional implementations, reference may be made to the introduction to the technical effects of the first aspect or corresponding implementations.

[0043] In a third aspect, a communication device is provided. The communication device may be the terminal device described in any one of the first to second aspects. The communication device possesses the functions of the terminal device described above. The communication device may be, for example, a terminal device, or other device including terminal device functions, or a system-on-chip (or chip) or other functional module. The system-on-chip or functional module is capable of implementing the functions of the terminal device, and the system-on-chip or functional module is, for example, disposed in the terminal device. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). The transceiver unit is capable of implementing both transmitting and receiving functions. When the transceiver unit implements the transmitting function, it may be referred to as a transmitting unit (sometimes also referred to as a transmitting module); when the transceiver unit implements the receiving function, it may be referred to as a receiving unit (sometimes also referred to as a receiving module). The transmitting unit and the receiving unit may be the same functional module, referred to as a transceiver unit, which is capable of both transmitting and receiving functions; alternatively, the transmitting unit and the receiving unit may be different functional modules, with the transceiver unit being a collective term for these functional modules.

[0044] In an optional embodiment, the transceiver unit (or, the receiving unit) is used to receive a first signal; the processing unit is used to perform a fast Fourier transform on the first signal to obtain a second signal, and the second signal includes frequency domain modulation symbols; the processing unit is also used to perform an inverse discrete Fourier transform on the second signal to obtain a third signal, and the third signal includes time domain modulation symbols; the processing unit is also used to obtain a fourth signal from the third signal.

[0045] In an optional embodiment, the communication device also includes a storage unit (sometimes also referred to as a storage module), and the processing unit is used to couple with the storage unit and execute the program or instructions in the storage unit, so as to enable the communication device to perform the functions of the terminal device described in any one of the first to second aspects above.

[0046] In a fourth aspect, a communication device is provided. The communication device may be the network device described in any one of the first to second aspects above. The communication device has the functions of the above-mentioned network device. The communication device is, for example, a network device, or other device including the functions of a network device, or a chip system (or, chip) or other functional module, and the chip system or functional module can realize the functions of the network device, and the chip system or functional module is, for example, provided in the network device. In an optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). For the implementation of the transceiver unit, reference may be made to the introduction of the third aspect.

[0047] In an optional embodiment, the processing unit is used to perform a discrete Fourier transform on the third signal to obtain a second signal, where the second signal includes frequency domain modulation symbols, the third signal includes a fourth signal, and the fourth signal includes time domain modulation symbols; the processing unit is also used to perform an inverse fast Fourier transform on the second signal to obtain a first signal; the transceiver unit (or, the sending unit) is used to send the first signal.

[0048] In an optional embodiment, the communication device also includes a storage unit (sometimes also referred to as a storage module), and the processing unit is used to couple with the storage unit and execute the program or instructions in the storage unit, enabling the communication device to perform the functions of the network device described in any one of the first to second aspects above.

[0049] In a fifth aspect, a communication device is provided. The communication device may be a terminal device, or a chip or chip system used in a terminal device. The communication device includes a communication interface and a processor, and optionally, a memory. The memory is used to store a computer program. The processor is coupled to the memory and the communication interface. When the processor reads the computer program or instructions, the communication device executes the method performed by the terminal device in the above aspects.

[0050] In a sixth aspect, a communication device is provided. The communication device may be a network device, or a chip or chip system used in a network device. The communication device includes a communication interface and a processor, and optionally, a memory. The memory is used to store a computer program. The processor is coupled to the memory and the communication interface. When the processor reads the computer program or instructions, the communication device executes the method performed by the network device in the above aspects.

[0051] In a seventh aspect, a communication system is provided, comprising a terminal device and a network device, wherein the terminal device is configured to execute the method described in the first or second aspect, and the network device is configured to execute the method described in the first or second aspect. For example, the terminal device may be implemented by the communication device described in the third or fifth aspect, and the network device may be implemented by the communication device described in the fourth or sixth aspect. Optionally, the communication system may further include other devices or equipment, for example, including other devices in addition to the terminal device and the network device, without limitation.

[0052] In an eighth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium is used to store a computer program or instruction. When the computer program or instruction is executed, the method performed by the terminal device and / or network device in the above aspects is implemented.

[0053] In a ninth aspect, a computer program product comprising instructions is provided, which enables the methods described in the above aspects to be implemented when the computer program or instructions are executed on a computer.

[0054] In a tenth aspect, a chip system is provided, comprising a processor and an interface, wherein the processor is configured to call and execute instructions from the interface so that the chip system implements the methods in the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1A is a schematic diagram of the generation process of a conventional OFDM waveform;

[0056] FIG1B is a schematic diagram of the generation process of a single-carrier OFDM waveform;

[0057] FIG2A is a schematic diagram of a conventional OFDM waveform for downlink transmission;

[0058] FIG2B is a schematic diagram of a single-carrier OFDM waveform for downlink transmission;

[0059] FIG3 is a schematic diagram of a method of using single-carrier OFDM for downlink transmission;

[0060] FIG4 is a schematic diagram of an application scenario of an embodiment of the present application;

[0061] FIG5 is a flow chart of a communication method provided in an embodiment of the present application;

[0062] FIG6 is a schematic diagram of an indication method of the first indication information in an embodiment of the present application;

[0063] 7A and 7B are two schematic diagrams of modulation using a high-order constellation diagram according to an embodiment of the present application;

[0064] FIG8 is a schematic diagram of a UE detecting a PDCCH according to an embodiment of the present application;

[0065] FIG9 is a schematic diagram of time division multiplexing of multiple downlink common channels within one OFDM symbol according to an embodiment of the present application;

[0066] FIG10 is a schematic diagram of time division multiplexing of PDCCH and PDSCH within one OFDM symbol in an embodiment of the present application;

[0067] FIG11 is a schematic diagram of the processing process at both ends of the network device and the UE in an embodiment of the present application;

[0068] FIG12A and FIG12B are schematic diagrams of two implementations of DMRS in an embodiment of the present application;

[0069] FIG13 is a schematic diagram of a device provided in an embodiment of the present application;

[0070] FIG14 is a schematic diagram of another device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0072] In the embodiments of the present application, the number of nouns, unless otherwise specified, means "singular noun or plural noun", that is, "one or more". "At least one" means one or more, and "plural" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, 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. For example, A / B means: A or B. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c means: 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.

[0073] In the embodiments of this application, ordinal numbers such as "first" and "second" are used to distinguish multiple objects and are not used to limit the size, content, order, timing, priority, or importance of multiple objects. In addition, the numbering of steps in the various embodiments introduced in this application is only to distinguish different steps and is not used to define the order between steps. For example, S501 can occur before S502, or after S502, or at the same time as S502.

[0074] Below, some terms or concepts in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0075] In the embodiment of the present application, the terminal device is a device with wireless transceiver function, which can be a fixed device, a mobile device, a handheld device (such as a mobile phone), a wearable device, a vehicle-mounted device, or a wireless device built into the above device (such as a communication module, a modem, or a chip system, etc.). The terminal device is used to connect people, objects, machines, etc., and can be widely used in various scenarios, such as but not limited to the following scenarios: perception scenarios, cellular communications, device-to-device communication (D2D), vehicle to everything (V2X), machine-to-machine / machine-type communications (M2M / MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, drones, robots, indoor commercial scenarios (such as mobile phone screen projection, file sharing, mobile phone to VR glasses video transmission) and other scenarios. When the terminal device is applied to V2X, it can also be called a V2X device, for example, a smart car (or intelligent car), a digital car, an unmanned car (or driverless car or pilotless car or automobile), a self-driving car (or autonomous car), a pure electric vehicle (or battery EV), a hybrid electric vehicle (HEV), a range-extended EV (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle (new energy vehicle), or a roadside unit (RSU). The terminal device can also be a device used in D2D communication, such as an electricity meter or water meter.

[0076] In addition, in the embodiments of the present application, the terminal device can also be a terminal device in an IoT system. IoT is an important part of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0077] The various terminal devices described above, if located on a vehicle (e.g., placed in or installed in a vehicle), can be considered as vehicle-mounted terminal devices, which are also referred to as on-board units (OBUs). The terminal device of the present application can also be an on-board module, on-board module, on-board component, on-board chip, or on-board unit built into a vehicle as one or more components or units, and the vehicle can implement the method of the present application through the built-in on-board module, on-board module, on-board component, on-board chip, or on-board unit.

[0078] The terminal device may sometimes be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication device, or user equipment, etc.

[0079] In the embodiments of the present application, the communication device for implementing the terminal device function may be a terminal device, or may be a device capable of supporting the terminal device to implement the function, such as a chip system, which may be installed in the terminal device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the terminal device as an example in which the device for implementing the terminal device function is a terminal device. In addition, for ease of description, the terminal device in the embodiments of the present application is described by taking a UE as an example.

[0080] The network devices in the embodiments of the present application include, for example, access network devices, and / or core network devices. The access network device is a device with wireless transceiver functions, which is used to communicate with the terminal device. The access network devices include but are not limited to base stations (base transceiver station (BTS), node B (Node B), evolved node B (eNodeB) / eNB, or the next generation node B (gNodeB) / gNB), transmission reception points (TRP), base stations subsequently evolved by the third generation partnership project (3GPP), access nodes in wireless fidelity (Wi-Fi) systems, wireless relay nodes, wireless backhaul nodes, etc. The base station can be: a macro base station, a micro base station, a pico base station, a small station, a relay station, etc. Multiple base stations can support networks with the same access technology, or they can support networks with different access technologies. The base station can include one or more co-station or non-co-station transmission and receiving points. The access network device may also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network device may also be a server, etc. For example, the network device in the V2X technology may be a road side unit (RSU). The following describes the access network device using a base station as an example. The base station can communicate with the terminal device, or it can communicate with the terminal device through a relay station. The terminal device can communicate with multiple base stations in different access technologies. The core network device is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the devices that implement core network functions in systems with different access technologies may be different, and the embodiments of the present application are not limited to this. Taking the fifth generation mobile communication technology (5G) system as an example, the core network equipment includes: access and mobility management function (AMF), session management function (SMF), policy control function (PCF) or user plane function (UPF), etc.

[0081] In the CU-DU architecture, the access network equipment may include one or more logical network elements such as a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU may be configured separately or included in the same network element, such as a baseband unit (BBU). The RU may be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0082] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in an open RAN (ORAN) system, CU may also be called an open CU (open CU, O-CU), DU may also be called an open DU (open DU, O-DU), CU-CP may also be called an open CU-CP (open CU-CP, O-CU-CP), CU-UP may also be called an open CU-UP (open CU-CP, O-CU-UP), and RU may also be called an open RU (open RU, O-RU). For convenience of description, the embodiments of the present application are described by taking CU, CU-CP, CU-UP, DU and RU as examples. Any of the CU (or CU-CP, CU-UP), DU and RU in the embodiments of the present application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0083] Optionally, in various embodiments of the present application, if the network device is a distributed architecture, for example, the network device includes a CU and a DU, or includes a CU-CP, a CU-UP and a DU, then the network device sends information to the UE, specifically, the DU included in the network device sends information to the UE; the network device receives information from the UE, specifically, the DU included in the network device receives information from the UE.

[0084] In the embodiments of the present application, the communication device for implementing the network device function may be a network device, or may be a device capable of supporting the network device to implement the function, such as a chip system, which may be installed in the network device. In the technical solutions provided in the embodiments of the present application, the technical solutions provided in the embodiments of the present application are described by taking the network device as an example of the device for implementing the network device function being a network device.

[0085] The following describes the technical features involved in the embodiments of this application.

[0086] In 4G or 5G communication systems, uplink transmission mainly uses the DFT-s-OFDM waveform, commonly known as single-carrier OFDM. Compared with the traditional OFDM waveform, the DFT-s-OFDM waveform adds a DFT processing process at the signal transmitting end, so that the signal has a lower PAPR, thereby improving the power efficiency of the UE. Please refer to Figures 1A and 1B. Figure 1A shows the generation process of the traditional OFDM waveform, and Figure 1B shows the generation process of the DFT-s-OFDM waveform. It can be seen that the traditional OFDM waveform maps the modulation symbols to the frequency domain resources, and then performs an inverse fast Fourier transform (IFFT) to transform it to the time domain before sending. Compared with the traditional OFDM waveform, the DFT-s-OFDM waveform adds a DFT processing process for the modulation symbols.

[0087] One reason single-carrier OFDM is not used for downlink is that the base station has a large number of antennas and RF channels. Even if single-carrier OFDM is used, it is still difficult to achieve a low PAPR due to the influence of digital precoding and multi-stream transmission.

[0088] However, the issue of introducing single-carrier OFDM in the downlink may be alleviated with the evolution of certain technologies. For example, if a base station supports multiple or even full connectivity—that is, a single digital channel can connect to multiple power amplifiers and antennas—then, in medium and light load scenarios, disabling most digital channels and performing low-stream or even single-stream transmission can mitigate the impact of factors such as digital precoding and multi-stream transmission on PAPR. Furthermore, the deployment of 5G or the sixth-generation (6G) communication systems in high-frequency bands, such as centimeter-wave, millimeter-wave, and even terahertz frequency bands, further facilitates the introduction of single-carrier OFDM. Because high-frequency base station antenna architectures primarily rely on analog precoding, they typically have fewer digital channels, such as 2, 4, or 8. This reduction, compared to 64, 128, or 256 digital channels in decimeter-wave bands, mitigates the impact of factors such as digital precoding and multi-stream transmission on PAPR.

[0089] Therefore, how to introduce single-carrier OFDM into downlink transmission is an urgent problem to be solved. As follows, the embodiments of the present application propose two ways to introduce single-carrier OFDM in downlink.

[0090] The first approach is to directly copy the uplink single-carrier OFDM solution to the downlink. The difference between uplink and downlink is that uplink transmission is a single UE sending a signal to the base station, while downlink transmission may be the base station sending a signal to multiple UEs at the same time. Therefore, if the uplink single-carrier OFDM is copied, the base station can send signals to different UEs in time during downlink transmission, that is, multiple UEs perform downlink transmission according to time division multiplexing. For example, referring to Figures 2A and 2B, Figure 2A is a schematic diagram of downlink transmission under the traditional OFDM waveform; Figure 2B is a schematic diagram of downlink transmission under single-carrier OFDM. It can be seen that the signals of UE1 and UE2 in Figure 2A are transmitted simultaneously, while the signals of UE1 and UE2 in Figure 2B are transmitted in time, which increases the signal transmission delay. Moreover, the time-sharing transmission method shown in Figure 2B will also increase the time proportion of downlink transmission of the base station and increase the power consumption of the base station.

[0091] The second approach is to perform DFT processing on signals from different UEs separately, then perform IFFT on all the signals to transform them into the time domain before transmitting them. (See Figure 3 for details.) This second approach allows simultaneous transmission even after the introduction of single-carrier OFDM, which helps reduce transmission latency. However, in this second approach, the base station performs DFT processing on signals from different UEs separately, which may cause the signals from each UE to overlap after the IFFT, resulting in an increase in the PAPR. This defeats the original purpose of introducing single-carrier OFDM.

[0092] In view of this, the embodiment of the present application can use single-carrier OFDM in downlink transmission, thereby reducing the PAPR of downlink transmission and improving the performance or power efficiency of downlink transmission. The embodiment of the present application takes into account that downlink transmission may be a network device sending signals to multiple users at the same time, or a network device sending signals on multiple channels. Therefore, the embodiment of the present application can also realize the simultaneous transmission of multi-user or multi-channel signals. When realizing the simultaneous transmission of multi-user or multi-channel signals, the embodiment of the present application does not need to time-share the signals of different users or different channels, thereby reducing the signal transmission delay. Moreover, at the signal transmitting end (such as a network device), the signals of multiple users or multiple channels can be uniformly discrete Fourier transformed, instead of performing discrete Fourier transform on the signals of different users or different channels separately. The corresponding signal receiving end (such as a UE) can uniformly perform inverse discrete Fourier transform on the received signals. If the signal transmitting end performs discrete Fourier transform on the signals of different users or different channels separately, then after the discrete Fourier transformed signals are subjected to inverse fast Fourier transform, the signals of different users or different channels may be superimposed on each other, resulting in an increase in PAPR. In the embodiment of the present application, the signal transmitting end uniformly performs discrete Fourier transform on the signals of multiple users or multiple channels. After the discrete Fourier transformed signals are subjected to inverse fast Fourier transform, the probability of superposition of signals of different users or different channels is reduced, thereby further reducing the PAPR.

[0093] The technical solutions provided in the embodiments of the present application can be applied to 4G systems, such as long term evolution (LTE) systems, or can be applied to 5G systems, such as new radio (NR) systems, or can also be applied to next generation mobile communication systems or other similar communication systems, such as 6G systems, etc., without specific limitations. In addition, the technical solutions provided in the embodiments of the present application can also be applied to D2D scenarios, such as NR-D2D scenarios, etc., or to V2X scenarios, such as NR-V2X scenarios, etc. For example, the embodiments of the present application can be used in fields such as factory manufacturing, whole-house intelligence, intelligent driving, assisted driving, intelligent connected vehicles, or indoor commercial scenarios.

[0094] Please refer to Figure 4, which is a schematic diagram of an application scenario of an embodiment of the present application. Figure 4 includes a network device, UE1, and UE2. The network device can use single-carrier OFDM to send downlink signals to these two UEs, or the network device can use single-carrier OFDM to send multiple channels to either of the two UEs. Figure 4 uses two UEs as an example, and there is no actual limit on the number of UEs.

[0095] The following describes the method provided by the embodiments of the present application in conjunction with the accompanying drawings. In the various embodiments of the present application, the time unit is, for example, a frame, a subframe, a slot, a mini-slot, an OFDM symbol group or an OFDM symbol, etc. In the following introduction, the time unit is mainly taken as an example of an OFDM symbol. That is, the "OFDM symbol" described below can be replaced by a "time unit". The frequency unit is, for example, a subcarrier or a subchannel, etc. In the various embodiments of the present application, "time domain modulation symbol", "frequency domain modulation symbol", etc. are included in the signal, such as a signal or a component of a signal; and "OFDM symbol" refers to a time unit, which is a different concept. In various embodiments of the present application, the downlink common channel is, for example, a broadcast channel for all UEs in a cell, and may include, for example, one or more of the following: a synchronization signal / physical broadcast channel block (SS / PBCH block), a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH) for scheduling system messages, paging messages, or random access channel (RACH) response messages, or a physical downlink shared channel (PDSCH) for carrying paging messages or RACH response messages. The SS / PBCH block may also be referred to as a synchronization signal block (SSB).

[0096] The various embodiments herein may be applied to the network architecture shown in Figure 4. For example, the UE described in the various embodiments herein may be UE1 or UE2 in Figure 4, and the network device described in the various embodiments herein may be the network device in Figure 4. In the figures corresponding to the various embodiments herein, all steps indicated by dashed lines are optional steps.

[0097] An embodiment of the present application provides a communication method. Please refer to FIG5 , which is a flowchart of the method.

[0098] S501: The network device performs DFT on the third signal to obtain a second signal.

[0099] Among them, the third signal may include time domain modulation symbols, and the second signal may include frequency domain modulation symbols. For example, the third signal includes a fourth signal, and the fourth signal includes one or more time domain modulation symbols. Optionally, the third signal may include other signals in addition to the fourth signal. For example, the third signal includes a fourth signal and a fifth signal (this article mainly takes the third signal including two signals as an example. In fact, the third signal may also include more signals, and the processing method is similar), and the fifth signal may also include one or more time domain modulation symbols. Among them, the number of time domain modulation symbols included in the fourth signal may be equal to or unequal to the number of time domain modulation symbols included in the fifth signal. Optionally, if the third signal includes multiple signals, the third signal may be a signal obtained by concatenating these multiple signals. For example, the third signal may be a signal obtained by concatenating the time domain modulation symbols included in these multiple signals.

[0100] The fourth signal and the fifth signal may be signals with different UEs as their target receiving ends, for example, the fourth signal may be targeted at a certain UE, while the fifth signal may be targeted at another UE. In this case, the fourth signal and the fifth signal may be signals of the same type, for example, both are PDCCHs, PDSCHs, or downlink common channels; or the fourth signal and the fifth signal may be signals of different types, for example, the fourth signal may be PDCCHs and the fifth signal may be PDSCHs, or the fourth signal may be PDSCHs and the fifth signal may be downlink common channels, etc.

[0101] Alternatively, the fourth signal and the fifth signal may be signals with the same UE as the target receiving end. In this case, the fourth signal and the fifth signal may be signals of different types, or signals of the same type.

[0102] That is, in the embodiment of the present application, DFT can be performed uniformly on multi-user or multi-channel signals, rather than performing DFT on signals from different users or different channels separately. If the network device performs DFT on signals from different users or different channels separately, then after performing IFFT on the DFT-posted signals, the signals from different users or different channels may overlap, resulting in an increase in PAPR. However, in the embodiment of the present application, the network device performs DFT on multi-user or multi-channel signals uniformly, and then after performing IFFT on the DFT-posted signals (this step will be described in S502), the probability of signals from different users or different channels overlapping can be reduced, thereby further reducing the PAPR.

[0103] The third signal may occupy M OFDM symbols, and the network device may perform DFT on the third signal, which may be to perform DFT on the information of the third signal on each OFDM symbol. For example, the network device performing DFT on the third signal to obtain the second signal may include the network device performing DFT on the information of the third signal on each OFDM symbol on the M OFDM symbols to obtain the second signal, and the second signal may correspond to the information of the third signal on all OFDM symbols on the M OFDM symbols. For example, the third signal occupies OFDM symbol 1 and OFDM symbol 2, and the information carried by the third signal on OFDM symbol 1 is, for example, referred to as information 1, and the information carried by the third signal on OFDM symbol 2 is, for example, referred to as information 2. The network device may perform DFT on information 1 to obtain information a, and perform DFT on information 2 to obtain information b. The second signal may include information a and information b. The following description is based on one OFDM symbol among the M OFDM symbols.

[0104] The second signal satisfies the following relationship, for example:

[0105] Wherein, X(k) represents the second signal, and k can represent the index of the frequency domain modulation symbol obtained after DFT transformation or the index of the subcarrier occupied by the frequency domain modulation symbol. x(n) represents the third signal, wherein n represents the index of the time domain modulation symbol in the OFDM symbol, for example, x(1) represents the first time domain modulation symbol in the OFDM symbol, and x(2) represents the second time domain modulation symbol in the OFDM symbol. For example, if the third signal includes the fourth signal, the fourth signal can be represented by x1(n); for another example, if the third signal includes the fourth signal and the fifth signal, the fourth signal can be represented by x1(n), and the fifth signal can be represented by x2(n). P represents the number of time domain modulation symbols included in the third signal, for example, P can be an integer multiple of 2, an integer multiple of 3, or an integer multiple of 5, etc., to reduce the complexity of DFT. If the third signal includes only the fourth signal, but the number of time-domain modulation symbols of the fourth signal included in the OFDM symbol is less than the DFT length P, then the third signal needs to be continuously padded with zeros to bring the length of the third signal to length P, and then the zero-padded third signal is subjected to DFT processing according to Formula 1. In this case, the fifth signal can also be considered an all-zero signal.

[0106] Optionally, before S501, the network device may further process the original information to obtain a third signal. If the third signal includes multiple signals, each of the multiple signals may correspond to corresponding original information. The network device may process each of the original information separately, and the third signal may include each processed original information. For example, if the third signal includes a fourth signal and a fifth signal, the fourth signal may correspond to the first original information, and the fifth signal may correspond to the second original information. The network device may process the first original information, for example, to obtain signal A, and the second original information, for example, to obtain signal B. The third signal may include signal A and signal B.

[0107] The following is an introduction using the example of a network device processing the first original information, wherein the network device's processing process for other original information is similar. For example, the network device adds a cyclic redundancy check (CRC) to the first original information, wherein the addition of the CRC is used by the target receiving end of the first original information to perform correctness verification on the decoded first original information. Optionally, if the first original information is a data channel, such as PDSCH, the CRC can be longer, such as 24 bits; or, if the first original information is a control channel, such as PDCCH, the CRC can be shorter, such as 16 bits. Alternatively, considering issues such as false alarms on the control channel, a longer CRC, such as 24 bits, is sometimes added to the control channel.

[0108] Optionally, if the first original information is a control channel, it is possible to further add a mask to the CRC, and the mask is generally used for the target receiving end of the first original information to perform an exclusive OR operation on the mask and the CRC. The mask may be related to the identifier of the target receiving end of the first original information, such as the cell radio network temporary identifier (C-RNTI) of the target receiving end; or, the mask may also be related to the identifier of the terminal group to which the target receiving end of the first original information belongs, such as a group for implementing a certain function, such as the UE included in the terminal group can be used to collaboratively implement a certain function, or the UE included in the terminal group can all implement a certain function, such as a power control function, etc. The identifier of the terminal group is, for example, the RNTI corresponding to the terminal group; or, the mask may also be related to a broadcast identifier. In this case, each UE in a cell can use the broadcast identifier, such as the RNTI used to transmit system broadcast messages.

[0109] After adding the CRC to the first original information, channel coding can be performed on the first original information with the CRC added according to a certain mother code rate (e.g., 1 / 3, corresponding to an input of f bits and an output of 3f bits). The channel coding algorithm used may include low-density parity check code (LDPC), convolutional coding, or polar coding. After performing channel coding, coded bits are obtained, and rate matching is performed on the coded bits according to the final coding rate to obtain the final output codeword. If the final coding rate is less than the mother code rate, the coded bits may be repeated; otherwise, if the final coding rate is greater than the mother code rate, the coded bits may be punctured.

[0110] For the above-mentioned output codeword, the network device can also perform constellation modulation to obtain time-domain modulation symbols. Constellation modulation methods include, for example, quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (QAM), or 64QAM. The time-domain modulation symbols obtained based on the first original information can be the fourth signal, and the time-domain modulation symbols obtained based on the second original information can be the fifth signal.

[0111] After performing constellation modulation, the network device obtains the third signal. The network device may then perform DFT on the third signal according to the method described above to obtain the second signal.

[0112] Optionally, the network device may map the second signal to subcarriers corresponding to M OFDM symbols. Generally speaking, in the frequency domain, resources are allocated according to the granularity of resource blocks (RBs), and one RB may include 12 subcarriers. Therefore, the number P of time-domain modulation symbols included in the third signal described above is generally an integer multiple of 12, thereby ensuring that the frequency-domain modulation symbols included in the second signal are mapped to an integer number of RBs.

[0113] After mapping, for each OFDM symbol in the M OFDM symbols, the network device may perform digital precoding on each of the multiple antenna ports used to transmit the second signal on the OFDM symbol to map the second signal to the multiple antenna ports corresponding to the OFDM symbol. For example, the digital precoding process satisfies the following relationship:

[0114] Formula 2 assumes that one OFDM symbol corresponds to two antenna ports for sending the second signal, and assumes that the two antenna ports send one stream of data. is the precoding matrix, X(k) represents the second signal. i (k) represents the signal of the second signal on the i-th antenna port on an OFDM symbol. In theory, digital precoding can be different for each subcarrier, but generally, considering the low frequency selectivity of the channel, digital precoding is generally performed with a granularity of several RBs. Furthermore, if it is considered to be more friendly to the PAPR of single-carrier OFDM, wideband precoding can be used, that is, the precoding matrix of all subcarriers is the same, but this process may lose some beam gain to obtain a reduction in PAPR. Optionally, the above digital precoding process can also be performed separately for each OFDM symbol.

[0115] The antenna ports described above are logical concepts, not physical antennas. Each antenna port can be a single digital channel or a virtualized representation of multiple digital channels. Subsequently, the signal from each antenna port can be further mapped to a physical antenna element through processes such as analog precoding.

[0116] S502: The network device performs IFFT on the second signal to obtain a first signal.

[0117] For example, the network device may perform IFFT on the digitally precoded signal on each of the multiple antenna ports used to transmit the second signal, respectively, to obtain the first signal. For each OFDM symbol in the M OFDM symbols, the network device may perform IFFT on the digitally precoded signal on each of the multiple antenna ports used to transmit the second signal, respectively. The first signal may correspond to the M OFDM symbols and to the multiple antenna ports.

[0118] Optionally, the first signal may satisfy the following relationship:

[0119] Among them, s i (t) is the information included in the first signal, s i (t) represents the time domain sample point of the signal on antenna port i after IFFT. Compared with the above DFT processing, N is generally greater than P, that is, oversampling is performed during the IFFT processing, so it is necessary to convert the length of S to P. i (k) Pad the frequency domain with zeros to make the length N. Therefore, after oversampling, one OFDM symbol among the M OFDM symbols may correspond to N time domain samples.

[0120] S503: The network device sends a first signal, and the UE receives the first signal accordingly.

[0121] The network device may directly send the first signal. For example, the network device may perform digital-to-analog conversion, up-conversion, and other operations on the first signal obtained in S502, and finally send the first signal over the air interface. Alternatively, the network device may also add a cyclic prefix (CP) to the first signal. For example, the network device may add a cyclic prefix (CP) to the first signal. i (t) A CP is added before, and then through subsequent digital-to-analog conversion, up-conversion and other operations, the first signal with the CP added is finally sent over the air interface.

[0122] The Fast Fourier Transform (FFT) and the DFT share the same principles, but utilize some fast transform algorithms in their implementation. The present embodiment does not distinguish between the DFT and the FFT, nor does it distinguish between the Inverse Discrete Fourier Transform (IDFT) and the IFFT. For example, the DFT in the present embodiment can be replaced by the FFT, or vice versa; the IDFT can be replaced by the IFFT, or vice versa; the IFFT can be replaced by the IDFT.

[0123] S504. The UE performs FFT on the first signal to obtain a second signal.

[0124] Regarding S504, the UE may have different implementations.

[0125] As an optional implementation, the UE may receive the complete first signal. For example, the first signal includes s i (t), where s i (t) represents the signal on antenna port i on the OFDM symbol. In this way, the UE can perform FFT on the first signal to obtain the second signal. For example, if the UE receives the first signal with a CP added, the UE can remove the CP to obtain the first signal. The UE performs FFT on the first signal to obtain the second signal. Considering that the CP added to the first signal is generally added at the granularity of OFDM symbols, in order to reduce the impact of multipath channels, reception based on all OFDM symbols occupied by the first signal (i.e., receiving the complete first signal) is a better reception method.

[0126] As another optional implementation method, the UE may receive part of the first signal, or receive part of the information in the first signal, instead of receiving the complete first signal. For example, for one OFDM symbol among the M OFDM symbols occupied by the first signal, the UE only receives the information of the first signal carried on part of the time domain samples in the OFDM symbol, but does not receive the information of the first signal carried on the remaining time domain samples in the OFDM symbol, for example, the part of the time domain samples are the time domain samples corresponding to the fourth signal, and the remaining time domain samples are the time domain samples corresponding to the fifth signal. Optionally, the UE may receive a signal in the first signal with the UE as the target receiving end, such as the fourth signal, but does not receive a signal in the first signal with other UEs as the target receiving end, such as the fifth signal. Optionally, the UE may determine the signal in the first signal with the UE as the target receiving end based on the first indication information, thereby receiving the signal. The first indication information will be introduced later.

[0127] If the UE only receives part of the information in the first signal, such as the time domain samples occupied by the fourth signal, the UE can perform an FFT on the received information and refer to the obtained signal as signal A, which may include frequency domain modulation symbols. Alternatively, if the UE only receives part of the information in the first signal, such as the time domain samples occupied by the fourth signal, and the signal transmitter (e.g., the network device) does not perform oversampling when performing IFFT on the second signal in S502, or performs oversampling but only filters out the bandwidth of the original non-oversampled portion when performing frequency domain filtering, the UE can directly obtain signal B based on the received information. Signal B includes time domain modulation symbols, which means that the UE does not need to perform processing such as FFT and IDFT.

[0128] Optionally, after receiving the first signal (or part of the information in the first signal), the UE may also perform channel estimation, equalization and other processing on the received information (the first signal, or part of the information in the first signal). For example, the first signal received by the UE (or part of the information in the first signal) carries channel distortion information. The UE may perform channel estimation based on a demodulation reference signal (DMRS), and then use the channel estimation result to equalize the received information to obtain a frequency domain signal without the influence of channel distortion. The above is an example of frequency domain channel estimation and equalization. In practice, the UE may also adopt time domain channel estimation and equalization, or adopt time-frequency joint channel estimation and equalization and other processing methods. The embodiments of the present application do not limit the channel estimation and equalization methods adopted by the UE.

[0129] The frequency domain position of the second signal is located within the first bandwidth, and the second signal may occupy M OFDM symbols in the time domain. The frequency domain unit included in the first bandwidth is, for example, a subcarrier or a resource block (RB), that is, the first bandwidth may include at least one subcarrier or at least one RB. The second signal is a frequency domain signal, for example, the second signal includes one or more frequency domain modulation symbols. The second signal may correspond to S in S501. i (k), such as S i (k) represents the signal of the second signal on the i-th antenna port on an OFDM symbol, where k can represent the index of the frequency domain modulation symbol within the first bandwidth or the index of the subcarrier occupied by the frequency domain modulation symbol.

[0130] The first bandwidth can be filtered out from the entire system bandwidth (e.g., carrier bandwidth or bandwidth part (BWP)) through the UE's filter, or the subcarrier corresponding to the first bandwidth can be determined from all subcarriers of the entire system bandwidth based on the subcarrier orthogonality characteristics of OFDM. The embodiment of this application does not limit the specific implementation method.

[0131] S505. The UE performs IDFT on the second signal to obtain a third signal.

[0132] The second signal occupies M OFDM symbols, and the UE performs IDFT on the second signal, specifically performing IDFT on the information of the second signal on each OFDM symbol in the M OFDM symbols, and the third signal may include the IDFT results on the M OFDM symbols. The number of points of the IDFT may be related to the number of frequency domain units included in the first bandwidth, for example, the number of points of the IDFT is equal to the number of frequency domain units included in the first bandwidth. For example, if the first bandwidth includes 48 subcarriers, the number of points of the IDFT may be 48.

[0133] S506. The UE obtains a fourth signal from the third signal.

[0134] For example, if the third signal only includes the fourth signal but not other signals, and the number of time-domain modulated signals included in the fourth signal is equal to the IDFT length, then S506 may not be executed; or, if the third signal only includes the fourth signal but not other signals, and the number of time-domain modulated signals included in the fourth signal is less than the IDFT length, then it is equivalent to the network device padding the fourth signal with zeros to the IDFT length, and the time-domain modulated symbols after zero padding can be regarded as the third signal, then the UE can obtain the fourth signal from the third signal, that is, obtain the original fourth signal before zero padding; or, if the third signal includes other signals in addition to the fourth signal, for example, it also includes the fifth signal (for example, the fourth signal is represented by x1(n), the fifth signal is represented by x2(n), and the third signal includes the concatenation of x1(n) and x2(n)), then the UE can obtain the fourth signal from the third signal. For an introduction to the fourth signal and the fifth signal, etc., please refer to the previous text.

[0135] For example, the third signal includes one or more time-domain modulation symbols. The fourth signal includes at least one time-domain modulation symbol. If the third signal also includes a fifth signal, the fifth signal may also include at least one time-domain modulation symbol, wherein the number of time-domain modulation symbols included in the fourth signal is equal to or unequal to the number of time-domain modulation symbols included in the fifth signal. The UE obtains the fourth signal from the third signal, that is, receives or intercepts the time-domain modulation symbols belonging to the fourth signal from the third signal. The manner in which the UE obtains the fourth signal from the third signal is related to the type of the fourth signal, as described below by way of example.

[0136] 1. The fourth signal is a PDSCH, or the fourth signal is included in the PDSCH.

[0137] In this case, the UE can obtain the fourth signal from the third signal based on the first indication information. The first indication information may indicate the resource location of the time-domain modulation symbol included in the fourth signal within an OFDM symbol. In other words, the UE can determine the resource location of the fourth signal from the third signal based on the first indication information, thereby being able to determine the fourth signal from the third signal.

[0138] Optionally, the first indication information indicates the resource position of the time domain modulation symbol included in the fourth signal within an OFDM symbol. For example, one indication method is that the first indication information may indicate the starting time domain modulation symbol of the fourth signal within an OFDM symbol, and indicate the number of time domain modulation symbols included in the fourth signal within an OFDM symbol; or, the first indication information may indicate the starting time domain modulation symbol of the fourth signal within an OFDM symbol, and the number of time domain modulation symbols included in an OFDM symbol may be preconfigured; or, another indication method is that the first indication information may indicate the ending time domain modulation symbol of the fourth signal within an OFDM symbol, and indicate the number of time domain modulation symbols included in the fourth signal within an OFDM symbol; or, yet another indication method is that the first indication information may indicate the starting time domain modulation symbol of the fourth signal within an OFDM symbol, and indicate the ending time domain modulation symbol of the fourth signal within an OFDM symbol. The fourth signal may occupy one OFDM symbol, or may occupy multiple OFDM symbols. If the fourth signal occupies multiple OFDM symbols, the first indication information may respectively indicate the resource position of the time domain modulation symbol included in the fourth signal in each of the OFDM symbols; or, if the resource position of the fourth signal in each OFDM symbol it occupies is the same, the first indication information may indicate the resource position of the time domain modulation symbol included in the fourth signal in one OFDM symbol. The indication range of the first indication information in the frequency domain may be the range of the number of points corresponding to the DFT / IDFT, that is, the indication range may be the range of the number of subcarriers corresponding to the RB included in the first bandwidth; or the indication range may also be the range corresponding to the bandwidth that can be allocated to the entire carrier or BWP, for example, if the carrier or BWP includes 100 RBs, then the indication range may be in M max =100×12=1200.

[0139] For example, refer to Figure 6, which is a schematic diagram of an indication method for the first indication information. For example, the number of DFT / IDFT points is 48, that is, the third signal may include 48 time-domain modulation symbols within an OFDM symbol. In this case, the first indication information may indicate a continuous segment of time-domain modulation symbols within the 48 time-domain modulation symbols, and this continuous segment of time-domain modulation symbols is the fourth signal. For example, in Figure 6, the first indication information indicates the first 24 time-domain modulation symbols of the 48 time-domain modulation symbols, and these 24 time-domain modulation symbols are the fourth signal (e.g., x1(n)).

[0140] The first indication information may come from a network device. For example, before the UE receives the first signal, or before the network device sends the first signal, the network device may send first information to the UE, the first information may schedule the fourth signal, and the first indication information may be included in the first information. The first information is included in the PDCCH, for example, the first information is downlink control information (DCI); or the first information may also be included in radio resource control (RRC) signaling; or the first information may also be included in signaling of other protocol layers, such as media access control (MAC) control element (CE), etc., without limitation.

[0141] Optionally, in addition to the first indication information, the first information may also include second indication information, and the second indication information may indicate the time domain resources and / or frequency domain resources occupied by the third signal. For example, the second indication information includes frequency domain resource indication information and / or time domain resource indication information, and the frequency domain resource indication information may indicate the frequency domain resources occupied by the third signal, and the time domain resource indication information may indicate the time domain resources occupied by the third signal. The indication granularity of the frequency domain resource indication information may be RB or RB group, etc., for example, the frequency domain resource indication information may indicate the starting RB of the third signal and the number of RBs occupied by the third signal. The indication granularity of the time domain resource indication information is, for example, OFDM symbol, for example, the time domain resource indication information may indicate the starting OFDM symbol of the third signal and the number of OFDM symbols occupied by the third signal. Equivalently, in an embodiment of the present application, in addition to indicating the time domain position and frequency domain position of the third signal, the network device may additionally indicate the position of the fourth signal in the third signal, so that the UE can obtain the fourth signal from the third signal.

[0142] Optionally, when the fourth signal is PDSCH, after the UE receives or intercepts the fourth signal, it can further process the fourth signal, such as constellation demodulation, decoding, CRC check, etc., to obtain the original information corresponding to the fourth signal (for example, called the first original information). The processing process is introduced as follows.

[0143] (1) Demodulation.

[0144] The UE first determines a modulation order, such as QPSK or 16QAM. Optionally, the UE may determine the modulation order based on an instruction from a network device. For example, if the first information described above includes third indication information, the third indication information may indicate a modulation and coding scheme (MCS) corresponding to the fourth signal. If the modulation and coding scheme includes the first modulation order, the fourth signal corresponds to the first modulation order. The UE demodulates the fourth signal based on all constellation points in the constellation diagram corresponding to the first modulation order to obtain demodulated bit information.

[0145] Alternatively, an embodiment of the present application provides another demodulation method, under which the modulation method is also improved accordingly. For example, when the network device modulates the transmitted signal, it can perform an order-up process. Specifically, when the network device sends multiple signals (for example, the third signal includes the fourth signal and the fifth signal), the modulation orders corresponding to different signals are the same or different. The so-called order-up process is, for example, when the modulation orders corresponding to different signals are different, the network device can modulate all signals according to the higher-order modulation order. For example, the third signal includes the fourth signal and the fifth signal, and the network device determines that the modulation order included in the MCS corresponding to the fourth signal is the first modulation order, and the modulation order included in the MCS corresponding to the fifth signal is the second modulation order, wherein the second modulation order is higher than the first modulation order. Then, the network device can modulate the fifth signal according to the second modulation order, and also modulate the fourth signal according to the second modulation order.

[0146] Among them, when the network device modulates the fourth signal according to the second modulation order, the information bits carried by the modulation symbol remain unchanged. For example, the first modulation order is QPSK, and each modulation symbol obtained by QPSK modulation can carry 2 information bits; the second modulation order is 16QAM, and the modulation symbol obtained by 16QAM modulation should originally carry 4 information bits, but when the network device uses 16QAM to modulate the fourth signal, each modulation symbol still carries 2 information bits instead of 4 information bits. Then, for the constellation diagram corresponding to the second modulation order, the network device may only use part of the constellation points in the constellation diagram when modulating the fourth signal, instead of all the constellation points in the constellation diagram (while the network device will normally use all the constellation points in the constellation diagram when modulating the fifth signal). Then, in an embodiment of the present application, when the network device uses the second modulation order to modulate the fourth signal, it can use R constellation points in the constellation diagram corresponding to the second modulation order to modulate the fourth signal, where R is less than the number of all constellation points in the constellation diagram, and R is a positive integer. Optionally, the Euclidean distance between any two of the R constellation points may be greater than or equal to a first threshold value, which is, for example, the Euclidean distance of all constellation points in a normal constellation diagram. Taking the first modulation order as QPSK and the second modulation order as 16QAM as an example, R=4. Referring to FIG7A , which is the constellation diagram corresponding to 16QAM, these four constellation points may be the four points at the four corners in FIG7A (i.e., the black points in FIG7A ). Taking the first modulation order as 16QAM and the second modulation order as 64QAM as an example, R=16. Referring to FIG7B , which is the constellation diagram corresponding to 64QAM, these 16 constellation points may be the black points in FIG7B .

[0147] Since the network device performs up-scaling during modulation, the UE can also perform corresponding up-scaling during demodulation. For example, a UE is the target receiving end of the fourth signal. The UE determines the MCS corresponding to the fourth signal based on the third indication information described above. The modulation order included in the MCS is the first modulation order, which is the modulation order corresponding to the fourth signal. The UE can also determine a second modulation order, which is greater than the first modulation order. The UE can then demodulate the fourth signal based on the second modulation order, rather than demodulating the fourth signal based on the first modulation order.

[0148] Similar to the modulation process, the UE can demodulate the fourth signal according to the R constellation points in the constellation diagram corresponding to the second modulation order. Optionally, the UE and the network device can use the same rule to determine the R constellation points, or the R constellation points can be indicated by the network device or predefined by a protocol.

[0149] The UE determines the second modulation order. For example, one determination method is for the UE to determine the second modulation order based on an instruction from a network device. For example, the second modulation order is the modulation order corresponding to the fifth signal. If the UE is also the target receiving end of the fifth signal, the UE may receive information for scheduling the fifth signal from the network device, such as second information. The second information may indicate the second modulation order. If the UE determines that the second modulation order is higher than the first modulation order, the UE may demodulate the fourth signal based on R constellation points in the constellation diagram corresponding to the second modulation order. Alternatively, the UE may demodulate the fifth signal based on all constellation points in the constellation diagram corresponding to the second modulation order.

[0150] Alternatively, if the UE is not the intended receiving end of the fifth signal, the UE may not receive the second information from the network device. In this case, the network device may indicate the second modulation order to the UE. For example, the first information sent by the network device to the UE may indicate the second modulation order, so that the UE can demodulate the fourth signal according to the R constellation points in the constellation diagram corresponding to the second modulation order.

[0151] The embodiment of the present application utilizes up-order processing to enable the UE to demodulate the fourth signal using constellation points with a greater Euclidean distance in the constellation diagram, thereby improving the demodulation performance of the fourth signal. Furthermore, since the modulation orders of the two signals are the same, the PAPR of the signals is not significantly affected. In other words, the embodiment of the present application improves demodulation performance without affecting the PAPR.

[0152] (2) Decoding.

[0153] The UE decodes the demodulated bit information. The UE can determine the coding rate of the fourth signal according to the indication of the network device. For example, the first information described above can indicate the coding rate. For example, the third indication information included in the first information can indicate the MCS corresponding to the fourth signal. The MCS includes the coding rate corresponding to the fourth signal in addition to the first modulation order. In addition, the UE can also determine the transport block size (TBS) corresponding to the fourth signal. Optionally, the UE can determine the transport block size corresponding to the fourth signal based on the first indication information and the third indication information. Further optionally, if multiple OFDM symbols are allocated to the PDSCH, for example, the time domain resource indication information included in the second indication information indicates multiple OFDM symbols, the UE can determine the transport block size corresponding to the fourth signal based on the time domain resource indication information, the first indication information and the third indication information. Alternatively, it can be considered that to determine the transport block size corresponding to the fourth signal, reference can be made to parameters such as the number of OFDM symbols allocated to the PDSCH, the number of time domain modulation symbols of the fourth signal in each OFDM symbol therein, and the MCS corresponding to the fourth signal. As shown in FIG6 , the signal required by the UE (the fourth signal) only occupies a portion of the time-domain modulation symbols (e.g., x1(n)) of the third signal. Even if the fourth signal fully occupies the first bandwidth in the frequency domain, the fourth signal also shares the frequency domain with other signals (e.g., x2(n)). Therefore, in this embodiment of the present application, the UE can determine the transport block size corresponding to the fourth signal based on the first indication information, without having to determine the transport block size corresponding to the fourth signal based on the frequency-domain resource indication information in the second indication information.

[0154] (3)CRC check.

[0155] After decoding, the UE can also perform a CRC check on the decoding result. If the check passes, the UE believes that the first original information from the network device has been correctly received; if the check fails, the UE believes that the first original information from the network device has not been correctly received. At this time, the UE can request the network device to retransmit, or it may not retransmit.

[0156] Optionally, the two downlink transmission modes of single-carrier OFDM and traditional OFDM supported by the embodiment of the present application can also be switched. For example, the network device can instruct the UE to use a certain transmission mode. One indication method is, for example, to indicate through a special value of the first indication information. For example, when the value of the first indication information is the first value, it indicates that the traditional OFDM transmission mode is used, and the UE can receive the first signal according to the traditional OFDM transmission mode; when the value of the first indication information is not the first value, it indicates that single-carrier OFDM is used, and the UE can receive the first signal according to the single-carrier OFDM transmission mode provided by the embodiment of the present application. Optionally, the first value is, for example, all 0 or all 1, or other values, and there is no limitation on this. For example, the first value can be all 0 because it is equivalent to not indicating any time domain modulation signal in the third signal as the fourth signal. Therefore, the useless state of all 0 can be used to indicate the fallback to the traditional non-DFT OFDM transmission mode, without the need to design independent indication signaling, saving the overhead of indication signaling. Among them, if the UE receives the first signal in accordance with the traditional OFDM method, the UE can execute the above S503 and S504 without having to execute S505 and S506. For example, when the UE obtains the second signal, it can directly perform constellation demodulation, decoding, CRC check and other processing on the second signal without having to perform IDFT and other processing on the second signal.

[0157] 2. The fourth signal is a downlink control channel. The downlink control channel is, for example, a physical downlink control channel, such as a PDCCH, or the downlink control channel may be other downlink control channels. The embodiment of the present application takes the PDCCH as an example.

[0158] In this case, before receiving the first signal, the UE may determine the resources occupied by the first signal, where the resources occupied by the first signal include frequency domain resources and time domain resources.

[0159] The frequency domain resources occupied by the first signal include, for example, the bandwidth for receiving the PDCCH, and may specifically include a control resource set (CORESET), a frequency domain subband (subband) or a BWP, etc. For example, the UE may determine the frequency domain resources occupied by the first signal through RRC dedicated signaling or broadcast signaling from the network device, or the UE may also determine the frequency domain resources occupied by the first signal based on information predefined by the protocol. Alternatively, the frequency domain resources occupied by the first signal may also be determined based on the blind detection of the UE. For example, the UE assumes at least two bandwidths, performs the above-mentioned IDFT processing according to the at least two bandwidths respectively to transform to the time domain, and then detects the PDCCH in the time domain modulation symbols corresponding to the at least two bandwidths respectively. For example, taking at least two bandwidths of 20RB and 80RB as an example, the network device selects 20RB or 80RB to send the PDCCH based on the actual bandwidth occupancy requirements, and the UE needs to perform blind detection on the above two bandwidths. For example, the UE assumes that the IDFT length corresponding to 20 RBs is 20×12=240 and transforms it to the time domain to detect the PDCCH. The UE can also assume that the IDFT length corresponding to 80 RBs is 80×12=960 and transforms it to the time domain to detect the PDCCH. Optionally, the at least two bandwidths can be associated with different DMRSs. For example, taking the at least two bandwidths of 20 RBs and 80 RBs as an example, different bandwidths can be associated with different DMRS sequences. The UE can determine the actual bandwidth of the current PDCCH by blindly detecting the different DMRS sequences. The UE then performs IDFT transformation to the time domain based on the actual bandwidth to detect the PDCCH. The different DMRS sequences can be different sequence root indices, different cyclic shifts of different sequences, or different scrambling codes of different sequences, or they can also be long or short truncated portions of the same sequence (for example, a 20 RB long sequence can be a portion of an 80 RB long sequence). The above-mentioned method for detecting the frequency domain resources occupied by the first signal can more effectively utilize a reasonable bandwidth to send and receive the PDCCH.

[0160] The time domain resources occupied by the first signal include, for example, M OFDM time domain symbols. The PDCCH may generally occupy some or all of the first to third OFDM symbols in a time slot. The UE may determine information such as the time slot in which the PDCCH is located and the number of OFDM symbols occupied in the time slot through RRC dedicated signaling or broadcast signaling from the network device, or based on information predefined in the protocol.

[0161] If the fourth signal is PDCCH, the UE can obtain the fourth signal by performing detection on the third signal, and the detection can also be called blind detection. For example, the UE can determine at least one candidate control channel from the time domain modulation symbols included in the third signal, each of which candidate control channels may include L control channel units, each of which may include at least one time domain modulation symbol, and L is a positive integer. The control channel unit is called, for example, a control channel element (CCE), or may have other names, and CCE is taken as an example below. Optionally, a control channel unit may include at least one resource element group (REG), and a REG may include 12 time domain modulation symbols. It can be seen that in the embodiment of the present application, the candidate control channel used for the UE to detect PDCCH no longer includes frequency domain units such as RB or subcarrier, but time domain modulation symbols. The UE detects the at least one candidate control channel and can obtain the fourth signal.

[0162] It can be understood that after obtaining the third signal, the UE can perform blind detection on candidate control channels at various possible locations in the time domain. If the result of a blind detection passes the CRC check, it means that the UE has correctly received the fourth signal. These candidate control channels can be divided into different CCE levels, and different CCE levels include different numbers of CCEs. For example, each candidate control channel at CCE level 2 may include 2 CCEs, each candidate control channel at CCE level 4 may include 4 CCEs, and so on. CCE levels include, for example, 1, 2, 4, 8, or 16.

[0163] The UE determines at least one candidate control channel from the time domain symbols included in the third signal. For example, one method includes that the UE can determine the starting CCE in the time domain modulation symbols included in the third signal based on the UE identifier, and the UE can determine the at least one candidate control channel based on the starting CCE and the number of detections of the candidate control channel. Optionally, the number of detections of the candidate control channel can also be determined based on the UE identifier, or predefined by the protocol, or preconfigured for the UE by the network device.

[0164] Optionally, the UE may perform detection on candidate control channels at various CCE levels separately, so the UE determines the starting CCE and the number of detections of the candidate control channel in the time domain modulation symbol included in the third signal, which may be performed separately for different CCE levels. For example, before blind detection of candidate control channels of various CCE levels, the UE may also determine the search space, which is generally defined based on different CCE levels, that is, the UE may determine the search space of each CCE level separately. Among them, the UE determines the search space of a certain CCE level, that is, it is necessary to determine the starting CCE of the search space corresponding to the CCE level in the third signal, and determine the number of detections of the candidate control channel corresponding to the search space corresponding to the CCE level. The search space generally includes a common search space and a UE-specific search space. For the common search space, its starting CCE does not need to be determined according to the UE identifier, but can be determined according to parameters shared by each UE or default parameters; for the UE-specific search space, the starting CCE may be determined by factors such as the UE identifier mentioned above.

[0165] Taking CCE level 4 as an example, assuming that the number of OFDM symbols occupied by CORESET is 2, and assuming that the total number of time domain modulation symbols included in the third signal in the above 2 OFDM time domain symbols is 2880, and assuming that one CCE includes 72 time domain modulation symbols, then 2880 / 72=40 CCEs, then the UE can determine the index of the starting CCE within these 40 CCEs (for example, the indexes of these 40 CCEs are 0 to 39) and the number of detection times of the candidate control channel according to the UE identifier.

[0166] Continuing with the above example, for example, the UE determines that the index of the starting CCE is 10 based on the UE's identifier, and the number of detections of the candidate control channel is 4. The UE can then determine that the search space of CCE level 4 includes CCEs with CCE indices 10 to 25. There are 4 candidate control channels in the search space, and the indices of the CCEs occupied by these 4 candidate control channels are {CCE10 to 13}, {CCE14 to 17}, {CCE18 to 21}, and {CCE22 to 25}, respectively. The UE can detect these 4 candidate control channels to determine whether there is a fourth signal.

[0167] 8 , taking the example of the UE detecting candidate control channels under CCE levels 1, 2, 4, 8, and 16 respectively, the UE finally detects the fourth signal in the search space of CCE level 4 (as shown by the “\” box in FIG8 ).

[0168] 3. The fourth signal is a downlink common channel. For example, the third signal includes at least one downlink common channel, and the fourth signal is one of the downlink common channels. For the UE, obtaining the fourth signal from the third signal may include determining each downlink common channel from the third signal.

[0169] When the third signal includes a downlink common channel, the first bandwidth described above may be, for example, the bandwidth of the downlink common channel. For example, if the downlink common channel is an SSB, the first bandwidth may be the bandwidth of the SSB, such as 80 RBs. Optionally, if the third signal includes multiple downlink common channels (e.g., the multiple downlink common channels may correspond to different beam directions), the bandwidths of the multiple downlink common channels may all be the first bandwidth described above, such as 80 RBs.

[0170] Optionally, at least one downlink common channel included in the third signal may be time-division multiplexed within a single OFDM symbol. For example, the third signal includes a fourth signal and a fifth signal, and both the fourth signal and the fifth signal are downlink common channels (wherein the fourth signal and the fifth signal may be downlink common channels of the same type, for example, both are SSBs; or the fourth signal and the fifth signal may be downlink common channels of different types, for example, the fourth signal is an SSB and the fifth signal is a PDCCH for scheduling system messages), and the fourth signal and the fifth signal may be time-division multiplexed within a single OFDM symbol.

[0171] Please refer to Figure 9, which is an example of a third signal including four downlink common channels. For example, these four downlink common channels are all SSBs, namely SSB0 to SSB3. For example, the UE determines that the third signal includes 960 time domain modulation symbols in one OFDM symbol (for example, the first bandwidth is 80 RBs, the UE performs IDFT on the second signal to obtain the third signal, and the number of points of the IDFT is 80×12=960, then the third signal includes 960 time domain modulation symbols in one OFDM symbol), and the UE can also determine the number of time domain modulation symbols occupied by one SSB in one OFDM symbol. For example, if the number is 240, the UE can determine that the OFDM symbol includes 4 SSBs. Optionally, for different SSBs in one OFDM symbol, the network device can adopt the same or different precoding methods; different SSBs in one OFDM symbol can point to the same or different transmission directions.

[0172] As introduced above, different downlink common channels can be time-division multiplexed within one OFDM symbol. In addition, other channels can also be time-division multiplexed within one OFDM symbol. For example, SSB and PDCCH, or SSB and PDSCH, or PBCH and PDSCH, or PBCH and PDSCH, or PDCCH and PDCCH, or PDCCH and PDSCH, or PDSCH and PDSCH, etc., can all be time-division multiplexed within one OFDM symbol. Among them, the aforementioned PDSCH may include downlink data, and / or include other public information (such as one or more of system messages, paging messages, or random access response messages). The following is an introduction to the time-division multiplexing of PDCCH and PDSCH within one OFDM symbol.

[0173] In current protocols, PDCCH and PDSCH generally occupy different OFDM symbols. For example, the PDCCH CORESET occupies the first two OFDM symbols of a time slot, and the PDSCH scheduled by the PDCCH occupies the last 12 OFDM symbols of the time slot. Alternatively, within the first two OFDM symbols, the PDCCH and the PDSCH scheduled by the PDCCH can also be frequency-division multiplexed by occupying different RBs. However, the embodiments of the present application propose that, under a single-carrier OFDM transmission mode, the PDCCH and PDSCH can also be time-division multiplexed within a single OFDM symbol.

[0174] For example, in each OFDM symbol in the OFDM symbols occupied by PDCCH (for example, the first OFDM symbol of a time slot (the number of OFDM symbols corresponding to CORESET is 1), or the first two OFDM symbols of a time slot (the number of OFDM symbols corresponding to CORESET is 2), or the first three OFDM symbols of a time slot (the number of OFDM symbols corresponding to CORESET is 3), etc., not specifically limited), PDCCH and PDSCH can be time-division multiplexed. Optionally, the PDSCH can be the PDSCH scheduled by the PDCCH, or it can be unassociated with the PDCCH. In addition, in the OFDM symbols not occupied by PDCCH (for example, including the last 13 OFDM symbols of a time slot, or including the last 12 OFDM symbols of a time slot, or including the last 11 OFDM symbols of a time slot), PDSCH can still be transmitted without transmitting PDCCH. Reference may be made to Figure 10, which shows an example of time division multiplexing of PDCCH and PDSCH within one OFDM symbol. Figure 10 takes the first two OFDM symbols of a time slot occupied by PDCCH as an example. It can be seen that in these two OFDM symbols, PDCCH and PDSCH are both time division multiplexed. It can be seen that the relationship between the PDCCH and the PDSCH scheduled by the PDCCH is that, for the first part of OFDM symbols occupied by PDCCH and PDSCH (e.g., the first two OFDM symbols), PDCCH and PDSCH are time division multiplexed within each OFDM symbol in the first part of OFDM symbols; while the second part of OFDM symbols (e.g., the remaining OFDM symbols in the OFDM symbols occupied by PDCCH and PDSCH, excluding the first part of OFDM symbols) are occupied by the above-mentioned PDSCH, but not by the above-mentioned PDCCH. The OFDM symbols occupied by PDCCH and PDSCH refer to all OFDM symbols occupied by PDCCH and PDSCH, which may include OFDM symbols occupied only by PDSCH but not by PDCCH, and OFDM symbols jointly occupied by PDCCH and PDSCH.

[0175] In the case where the PDCCH and the PDSCH are time-division multiplexed within one OFDM symbol, for example, the signal that the UE needs to detect is the PDCCH (for example, the PDCCH is the fourth signal), the UE can determine the candidate control channel from the time-domain modulation symbols included in the OFDM symbol, and can determine the fourth signal by detecting the candidate control channel. Taking the first two OFDM symbols of a time slot occupied by the PDCCH as an example, the UE performs an IDFT on the second signal based on the first bandwidth (for example, the CORESET bandwidth, for example, 20 RBs) to obtain the third signal, and the number of points of the IDFT is 20×12=240. Assume that the UE detects the PDCCH according to CCE level 4 in the time domain modulation symbols included in an OFDM symbol occupied by the third signal, where, for example, the third signal occupies 2 OFDM symbols, then each OFDM symbol occupied by the third signal includes 240 time domain modulation symbols, and these 2 OFDM symbols include a total of 240×2=480 time domain modulation symbols. Then the UE detects the PDCCH of CCE level 4 within these 480 time domain modulation symbols, and the PDCCH occupies 288 time domain modulation symbols (assuming that each CCE occupies 6 RBs, then 4 CCEs occupy 4×6×12=288 time domain modulation symbols in two OFDM symbols). Then, in addition to the time domain symbols occupied by the PDCCH, the remaining time domain modulation symbols within these two OFDM symbols can be occupied by the PDSCH (for example, the PDSCH can occupy a total of 8×12×2=192 time domain modulation symbols). In addition, the 20 RBs of the remaining 12 OFDM in the time slot only transmit the PDSCH, not the PDCCH. In the above example, other information that may be carried by these two OFDM symbols, such as DMRS, is not considered. This is only used as an example to introduce the solution.

[0176] For scenarios where other channels are time-division multiplexed within an OFDM, the implementation principle is similar and will not be elaborated on here.

[0177] In summary, please refer to Figure 11 again, which is a schematic diagram of the processing process at both ends of the network device and the UE in an embodiment of the present application. In an embodiment of the present application, the network device can perform a joint DFT on the signals of multiple UEs (or signals of multiple channels) instead of performing DFT independently. Compared with the solution of performing DFT independently, the network device in the embodiment of the present application can reduce the probability of superposition of signals from different users or different channels after performing IFFT on the unified DFT signal, thereby further reducing the PAPR.

[0178] Optionally, in an embodiment of the present application, in addition to sending the first signal, the network device may also send a DMRS, so that the UE may perform channel estimation on the received signal based on the DMRS.

[0179] As an optional implementation of DMRS, the network device can send DMRS separately for different signals, for example, the DMRS and the signal can have a one-to-one correspondence. For example, the network device can send DMRS 1 for the fourth signal (or for the first original information) and DMRS2 for the fifth signal (or for the second original information). The target receiving end of the fourth signal can perform channel estimation based on DMRS 1 to demodulate the fourth signal; the target receiving end of the fifth signal can perform channel estimation based on DMRS 2 to demodulate the fifth signal. In this case, if the first signal includes multiple signals (or the third signal includes multiple signals), the network device can send multiple DMRS. Optionally, these multiple DMRSs can be included in one OFDM symbol. For example, these multiple DMRSs can be frequency-division multiplexed or code-division multiplexed within the OFDM symbol. For example, one frequency-division multiplexing method is a comb distribution. For example, for the aforementioned case where the PDCCH and PDSCH are time-division multiplexed within an OFDM symbol, if the PDCCH is sent using a wide beam and the PDSCH is sent using a narrow beam, the PDCCH and the PDSCH can correspond to different DMRSs, respectively, to improve the accuracy of channel estimation. Please refer to Figure 12A, which is a schematic diagram of the comb distribution of DMRS within an OFDM symbol. Figure 12A takes two DMRSs as an example, where "\" represents one DMRS and " / " represents another DMRS. The blank box in Figure 12A represents a first signal, where the first signal includes two signals; or the blank box in Figure 12A represents a third signal, where the third signal includes two signals, such as a fourth signal and a fifth signal.

[0180] Alternatively, as another optional implementation of DMRS, the network device can transmit a single DMRS for different signals. This DMRS can be used for channel estimation for all signals included in the first signal (or for all signals included in the third signal). That is, multiple signals can share a single DMRS. For example, in the case where multiple signals are time-division multiplexed within a single OFDM symbol, the network device can simply transmit a single DMRS. In this case, the UE can demodulate any signal included in the third signal based on this DMRS. Sharing a single DMRS for multiple signals helps reduce the number of DMRSs, saves transmission overhead, and allows more resources to be used to transmit other signals. See Figure 12B for an example of different signals sharing a single DMRS. The shading in Figure 12B represents a DMRS, which, for example, occupies a single OFDM symbol. The blank boxes in Figure 12B represent a first signal, where the first signal includes multiple signals; or the blank boxes in Figure 12B represent a third signal, where the third signal includes multiple signals. However, in Figure 12B, the multiple signals included in the first signal (or third signal) all use the shaded DMRS.

[0181] Optionally, regardless of whether the network device sends DMRS separately for different signals or sends one DMRS for all signals, the DMRS and part or all of the signals included in the third signal can occupy different OFDM symbols. For example, if the third signal includes a fourth signal and a fifth signal, the DMRS and the fourth signal can occupy different OFDM symbols, and / or the DMRS and the fifth signal can occupy different OFDM symbols. For example, in Figures 12A and 12B, the DMRS and the signals included in the third signal occupy different OFDM symbols. The DMRS and the signal are located in different OFDM symbols, which can ensure that channel estimation can be performed in the frequency domain on the OFDM symbol where the DMRS is located, without the need to support time division multiplexing of the DMRS and the signal within one OFDM, thereby simplifying processes such as channel estimation and demodulation and equalization.

[0182] As mentioned above, if a network device sends multiple DMRSs, these multiple DMRSs can be code-division multiplexed, for example, these multiple DMRSs can be superimposed in the time domain and / or frequency domain; and the signals corresponding to these multiple DMRSs may not be superimposed in the time domain. For example, the network device sends DMRS1 and DMRS2, and the time domain positions and frequency domain positions of these two DMRSs are the same, and these two DMRSs are code-division multiplexed. DMRS1 corresponds to the fourth signal, and DMRS2 corresponds to the fifth signal. The time domain resources of the fourth signal and the fifth signal are different. For example, the fourth signal and the fifth signal respectively occupy (or include) different time domain modulation symbols in the third signal. For example, the target receiving end of the fourth signal performs channel estimation based on DMRS1. Since DMRS1 is sent in superposition with DMRS2, the received power spectral density of DMRS1 is actually lower than the received power corresponding to the fourth signal. For example, the power spectral density of DMRS1 is half of the fourth signal. Therefore, to improve demodulation accuracy, in an embodiment of the present application, when demodulating the fourth signal, the UE may, in addition to referring to the channel estimation result obtained based on the DMRS corresponding to the fourth signal, also refer to power ratio indication information. This power ratio indication information may indicate the power ratio between the DMRS corresponding to the fourth signal and the fourth signal. This power ratio may be less than or equal to 1. For example, the power ratio may be selected between 0.5 and 1, i.e., the power ratio may be 0.5 or 1. For example, when neither the DMRS nor the fourth signal is superimposed with other signals, a power ratio of 1 is used; alternatively, if the DMRS is superimposed with other DMRSs (e.g., code division), and the fourth signal is not superimposed with other signals in the time domain, a power ratio of 0.5 or other pre-set or indicated power ratio less than 1 may be used. The UE may obtain the received power corresponding to the fourth signal based on the channel estimation result and the power ratio, thereby demodulating the fourth signal. For example, one way to obtain the received power corresponding to the fourth signal based on the channel estimation result and the power ratio is to calculate the product of the channel estimation result and the power ratio, and use this product as the received power corresponding to the fourth signal.

[0183] The power ratio indication information comes from, for example, a network device, for example, the network device sends the power ratio indication information through RRC dedicated signaling, broadcast signaling, or physical layer signaling (such as DCI); alternatively, the power ratio indication information may also be predefined by a protocol. The power ratio indication information may occupy one or more bits. For example, if the power ratio indication information occupies one bit, if the value of the bit is "1" or "true", it indicates that the power ratio is 1; alternatively, if the indication of the bit is "0" or "false", it indicates that the power ratio is 0.5. Alternatively, the power ratio indication information may occupy more bits, and accordingly there may be more values ​​and / or more indication methods, which are not limited.

[0184] In summary, the embodiments of the present application can use single-carrier OFDM in downlink transmission, thereby reducing the PAPR of downlink transmission and improving the performance of downlink transmission. The embodiments of the present application take into account that downlink transmission may be a network device sending signals to multiple users simultaneously, or a network device sending signals on multiple channels. Therefore, the embodiments of the present application can also implement simultaneous transmission of multi-user or multi-channel signals. For example, the third signal may include multiple signals. When implementing simultaneous transmission of multi-user or multi-channel signals, the embodiments of the present application do not need to time-share the signals of different users or different channels, thereby reducing signal transmission delay. Moreover, the multi-user or multi-channel signals can be uniformly DFTed at the signal transmitting end, rather than performing DFT on the signals of different users or different channels separately. The corresponding signal receiving end can uniformly perform IDFT on the received signals. If the signal transmitting end (e.g., the network device) performs DFT on the signals of different users or different channels separately, then after performing IFFT on the DFT-posted signals, the signals of different users or different channels may be superimposed on each other, resulting in an increase in PAPR. In the embodiment of the present application, the signal transmitting end performs DFT on the signals of multiple users or multiple channels uniformly. After performing IFFT on the DFT signals, the probability of superposition of signals of different users or different channels is reduced, thereby further reducing the PAPR.

[0185] FIG13 is a schematic diagram of the structure of a communication device provided in an embodiment of the present application. The communication device 1300 may be the circuit system of the UE described in the embodiment shown in FIG5 , and is used to implement the method corresponding to the UE in the above method embodiment. Alternatively, the communication device 1300 may be the circuit system of the network device described in the embodiment shown in FIG5 , and is used to implement the method corresponding to the network device in the above method embodiment. For example, one circuit system is a chip system.

[0186] The communication device 1300 includes at least one processor 1301. Processor 1301 can be used for internal processing of the device, implementing certain control processing functions. Optionally, processor 1301 includes instructions. Optionally, processor 1301 can store data. Optionally, different processors can be independent devices, located in different physical locations, or on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, on one or more integrated circuits.

[0187] Optionally, the communication device 1300 includes one or more memories 1303 for storing instructions. Optionally, data may also be stored in the memories 1303. The processor and memory may be provided separately or integrated together.

[0188] Optionally, the communication device 1300 includes a communication line 1302 and at least one communication interface 1304. Since the memory 1303, the communication line 1302 and the communication interface 1304 are all optional, they are indicated by dotted lines in FIG13 .

[0189] Optionally, the communication device 1300 may further include a transceiver and / or an antenna. The transceiver may be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver, a transceiver circuit, an input / output interface, etc., and is used to implement the transceiver function of the communication device 1300 via an antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter may be used to generate a radio frequency signal from a baseband signal, and the receiver may be used to convert the radio frequency signal into a baseband signal.

[0190] The processor 1301 may include a general-purpose central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present application.

[0191] Communication link 1302 may include a pathway for transmitting information between the aforementioned components.

[0192] The communication interface 1304 uses any transceiver or other device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0193] The memory 1303 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 1303 may exist independently and be connected to the processor 1301 via the communication line 1302. Alternatively, the memory 1303 may be integrated with the processor 1301.

[0194] The memory 1303 is used to store computer-executable instructions for executing the solution of the present application, and the execution is controlled by the processor 1301. The processor 1301 is used to execute the computer-executable instructions stored in the memory 1303, thereby implementing the steps performed by the UE or network device in the embodiment shown in FIG.

[0195] Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application code, which is not specifically limited in the embodiments of the present application.

[0196] In a specific implementation, as an embodiment, the processor 1301 may include one or more CPUs, such as CPU0 and CPU1 in FIG13 .

[0197] In a specific implementation, as an embodiment, the communication device 1300 may include multiple processors, such as the processor 1301 and the processor 1305 in FIG13 . Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. The processor herein may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0198] When the device shown in FIG13 is a chip, such as a UE chip or a network device chip, the chip includes a processor 1301 (and may also include a processor 1305), a communication circuit 1302, and a communication interface 1304. Optionally, the chip may include a memory 1303. Specifically, the communication interface 1304 may be an input interface, a pin, or a circuit. The memory 1303 may be a register, a cache, or the like. The processor 1301 and the processor 1305 may be a general-purpose CPU, a microprocessor, an ASIC, or one or more integrated circuits for controlling the execution of the program of any of the above-described embodiments of the communication method.

[0199] The embodiment of the present application can divide the functional modules of the device according to the above-mentioned method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. For example, in the case of dividing each functional module according to each function, Figure 14 is a schematic diagram of a device, and the device 1400 can be the UE or network device involved in the above-mentioned various method embodiments, or a chip in the UE or a chip in the network device. The device 1400 includes a processing unit 1402 and a transceiver unit 1401.

[0200] It should be understood that the device 1400 can be used to implement the steps performed by the UE or network device in the communication method of the embodiment of the present application. The relevant features can refer to the embodiment shown in Figure 5 above and will not be repeated here.

[0201] Optionally, the functions / implementation processes of the transceiver unit 1401 and the processing unit 1402 in FIG14 may be implemented by the processor 1301 in FIG13 calling computer-executable instructions stored in the memory 1303. Alternatively, the functions / implementation processes of the processing unit 1402 in FIG14 may be implemented by the processor 1301 in FIG13 calling computer-executable instructions stored in the memory 1303, and the functions / implementation processes of the transceiver unit 1401 in FIG14 may be implemented by the communication interface 1304 in FIG13.

[0202] Optionally, when the device 1400 is a chip or circuit, the functions / implementation processes of the transceiver unit 1401 may also be implemented via pins or circuits. Optionally, the transceiver unit 1401 may include a transmitting unit and / or a receiving unit, where the transmitting unit is configured to implement the transmitting function and the receiving unit is configured to implement the receiving function. Alternatively, the transceiver unit 1401 may be an integral module capable of implementing the transmitting function and / or the receiving function. Optionally, the transceiver unit 1401 may be implemented via a transceiver.

[0203] The present application also provides a computer-readable storage medium, which stores a computer program or instruction. When the computer program or instruction is executed, the method performed by the UE or network device in the aforementioned method embodiment is implemented. In this way, the functions described in the above embodiments can be implemented in the form of software functional units and sold or used as independent products. Based on this understanding, the technical solution of the present application can be essentially or in other words, the part that contributes or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. Storage media include various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0204] The present application also provides a computer program product, which includes: computer program code, which, when running on a computer, enables the computer to execute the method executed by the UE or the network device in any of the aforementioned method embodiments.

[0205] An embodiment of the present application further provides a processing device, including a processor and an interface; the processor is used to execute the method executed by the UE or network device involved in any of the above method embodiments.

[0206] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0207] The various illustrative logic units and circuits described in the embodiments of the present application can be implemented or operated by a general-purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor, and optionally, the general-purpose processor can also be any conventional processor, controller, microcontroller or state machine. The processor can also be implemented by a combination of computing devices, such as a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

[0208] The steps of the methods or algorithms described in the embodiments of the present application can be directly embedded in hardware, software units executed by a processor, or a combination of the two. The software unit can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or other storage media in any form known in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Alternatively, the storage medium can also be integrated into the processor. The processor and storage medium can be provided in an ASIC, which can be provided in a terminal device. Alternatively, the processor and storage medium can also be provided in different components in the terminal device.

[0209] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0210] The contents of the various embodiments of this application can refer to each other. If there is no special explanation and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0211] It is understood that in the embodiments of the present application, the UE and / or the network device may perform some or all of the steps in the embodiments of the present application. These steps or operations are merely examples. In the embodiments of the present application, other operations or variations of various operations may also be performed. In addition, the various steps may be performed in a different order than those presented in the embodiments of the present application, and it is possible that not all operations in the embodiments of the present application need to be performed.

Claims

1. A communication method, characterized in that, The method includes: Receiving a first signal; Performing a fast Fourier transform on the first signal to obtain a second signal, where the second signal includes frequency-domain modulation symbols; Performing an inverse discrete Fourier transform on the second signal to obtain a third signal, where the third signal includes time-domain modulation symbols; Obtaining a fourth signal from the third signal.

2. The method according to claim 1, wherein Obtaining a fourth signal from the third signal includes: Obtaining the fourth signal from the third signal according to first indication information, where the first indication information is used to indicate the resource position of the time-domain modulation symbols included in the fourth signal within a time unit.

3. The method according to claim 2, wherein The first indication information being used to indicate the resource position of the time-domain modulation symbols included in the fourth signal within a time unit includes: The first indication information being used to indicate the starting time-domain modulation symbol of the fourth signal within the time unit, and to indicate the number of time-domain modulation symbols of the fourth signal within the time unit.

4. The method according to claim 2 or 3, characterized in that, The method further includes: Determining the time-domain resources and frequency-domain resources occupied by the third signal according to second indication information.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: Receiving first information, where the first information is used to schedule the fourth signal, and where the first information includes first indication information, and the first indication information is used to indicate the resource position of the time-domain modulation symbols included in the fourth signal within a time unit.

6. The method according to claim 5, wherein The first information further includes third indication information, and the third indication information is used to indicate the modulation and coding scheme of the fourth signal.

7. The method according to claim 6, wherein The method further includes: Determining the transport block size corresponding to the fourth signal according to the first indication information and the third indication information.

8. The method according to claim 1, wherein Obtaining a fourth signal from the third signal includes: Determining at least one candidate control channel from the time-domain modulation symbols included in the third signal, where each of the candidate control channels includes L control channel units, and each of the control channel units includes at least one time-domain modulation symbol, and L is a positive integer; Detecting the at least one candidate control channel.

9. The method according to claim 8, characterized in that, Determining at least one candidate control channel from the time-domain modulation symbols included in the third signal includes: Determining a starting control channel unit among the time-domain modulation symbols included in the third signal; Determining the at least one candidate control channel according to the starting control channel unit and the number of detections of the candidate control channel.

10. The method according to any one of claims 1 to 9, characterized in that, The third signal includes the fourth signal and a fifth signal, The fourth signal and the fifth signal are time-division multiplexed within an OFDM symbol.

11. The method according to any one of claims 1 to 10, characterized in that, The third signal includes the fourth signal and a fifth signal, the fourth signal is carried on a first channel, and the fifth signal is carried on a second channel.

12. According to the method of claim 11, wherein The first channel is a physical downlink control channel, the second channel is a physical downlink shared channel, and the first channel is used to schedule the second channel; or, Both the first channel and the second channel are physical downlink control channels; or, Both the first channel and the second channel are downlink common channels.

13. The method according to any one of claims 1 to 12, characterized in that, The third signal includes the fourth signal and a fifth signal, and the method further includes: Receive a demodulation reference signal, where the demodulation reference signal is used for channel estimation of the fourth signal and the fifth signal, and / or the demodulation reference signal occupies different time units from the fourth signal and / or the fifth signal.

14. The method according to any one of claims 1 to 12, characterized in that The method further includes: Receive a demodulation reference signal and power ratio indication information, where the demodulation reference signal occupies a different time unit from the fourth signal, the demodulation reference signal is used for channel estimation of the fourth signal, and the power ratio indication information is used to indicate the power ratio of the demodulation reference signal to the fourth signal, and the power ratio is less than or equal to 1; Demodulate the fourth signal according to the result of the channel estimation and the power ratio.

15. The method according to any one of claims 1 to 14, characterized in that, The method further includes: Determine a first modulation order and a second modulation order, where the first modulation order is the modulation order included in the modulation and coding scheme corresponding to the fourth signal, and the second modulation order is higher than the first modulation order; Demodulate the fourth signal according to some constellation points in the constellation diagram corresponding to the second modulation order.

16. The method according to any one of claims 1 to 14, characterized in that The third signal includes the fourth signal and the fifth signal, and the method further includes: Determine a first modulation order and a second modulation order, where the first modulation order is the modulation order included in the modulation and coding scheme corresponding to the fourth signal, and the second modulation order is the modulation order included in the modulation and coding scheme corresponding to the fifth signal, and the second modulation order is higher than the first modulation order; Demodulate the fourth signal according to some constellation points in the constellation diagram corresponding to the second modulation order; Demodulate the fifth signal according to all constellation points in the constellation diagram corresponding to the second modulation order.

17. The method according to any one of claims 1 to 16, characterized in that Perform an inverse discrete Fourier transform on the second signal to obtain a third signal, including: Perform the inverse discrete Fourier transform on the information of the second signal in each of the M time units, where the M time units are the time units occupied by the first signal, and M is a positive integer, to obtain the third signal.

18. A communication method, characterized in that, The method includes: Perform a discrete Fourier transform on the third signal to obtain a second signal, where the second signal includes frequency-domain modulation symbols, the third signal includes a fourth signal, and the fourth signal includes time-domain modulation symbols; Perform an inverse fast Fourier transform on the second signal to obtain a first signal; Transmit the first signal.

19. The method according to claim 18, wherein The method further includes: Transmit first information, where the first information is used to schedule the fourth signal, and the first information includes first indication information, and the first indication information is used to indicate the resource position of the time-domain modulation symbols included in the fourth signal within one time unit.

20. The method according to claim 19, wherein The first indication information is used to indicate the resource position of the time-domain modulation symbols included in the fourth signal within one time unit, including: The first indication information is used to indicate the starting time-domain modulation symbol of the fourth signal within the one time unit, and to indicate the number of time-domain modulation symbols of the fourth signal within the one time unit.

21. The method according to claim 19 or 20, characterized in that, The first information further includes second indication information, and the second indication information is used to indicate the time-domain resources and frequency-domain resources occupied by the third signal.

22. The method according to any one of claims 19 to 21, characterized in that The first information further includes third indication information for indicating a modulation and coding scheme of the fourth signal, and the first indication information and the third indication information are used to determine a transport block size corresponding to the fourth signal.

23. The method according to claim 18, characterized in that, Before performing inverse fast Fourier transform on the second signal, the method further includes: Determining at least one candidate control channel from time-domain modulation symbols included in the third signal, where each candidate control channel includes L control channel units, and each of the control channel units includes at least one time-domain modulation symbol, and L is a positive integer; Determining the fourth signal from the at least one candidate control channel, where the fourth signal is one of the at least one candidate control channels.

24. The method according to claim 23, wherein Determining at least one candidate control channel from time-domain modulation symbols included in the third signal includes: Determining a starting control channel unit in the time-domain modulation symbols included in the third signal; Determining the at least one candidate control channel according to the starting control channel unit and a detection number of the candidate control channel.

25. The method according to any one of claims 18 to 24, characterized in that The third signal includes the fourth signal and a fifth signal, The fourth signal and the fifth signal are time-division multiplexed within one OFDM symbol.

26. The method according to any one of claims 18 to 25, characterized in that The third signal includes the fourth signal and a fifth signal, where the fourth signal is carried on a first channel and the fifth signal is carried on a second channel.

27. The method according to claim 26, wherein The first channel is a physical downlink control channel, the second channel is a physical downlink shared channel, and the first channel is used to schedule the second channel; or Both the first channel and the second channel are physical downlink control channels; or Both the first channel and the second channel are downlink common channels.

28. The method according to any one of claims 18 to 27, characterized in that The third signal includes the fourth signal and a fifth signal, and the method further includes: Transmitting a demodulation reference signal for channel estimation of the fourth signal and the fifth signal, and / or the demodulation reference signal occupies a different time unit from the fourth signal and / or the fifth signal.

29. The method according to any one of claims 18 to 27, characterized in that, The method further includes: Transmitting a demodulation reference signal and power ratio indication information, where the demodulation reference signal occupies a different time unit from the fourth signal, the demodulation reference signal is used for channel estimation of the fourth signal, and the power ratio indication information is used to indicate a power ratio of the demodulation reference signal to the fourth signal, and the power ratio is less than or equal to 1.

30. The method according to any one of claims 18 to 29, characterized in that The method further includes: Determining a first modulation order and a second modulation order, where the first modulation order is a modulation order included in a modulation and coding scheme corresponding to the fourth signal, and the second modulation order is higher than the first modulation order; Performing constellation modulation on the fourth signal according to partial constellation points in a constellation diagram corresponding to the second modulation order.

31. The method according to claim 30, wherein The third signal includes the fourth signal and a fifth signal, the second modulation order is a modulation order included in a modulation and coding scheme corresponding to the fifth signal, and the method further includes: Performing constellation modulation on the fifth signal according to all constellation points in a constellation diagram corresponding to the second modulation order.

32. The method according to any one of claims 18 to 31, characterized in that, Perform a discrete Fourier transform on a third signal to obtain a second signal, including: Perform the discrete Fourier transform on the information of the third signal for each of M time units, where the M time units are the time units occupied by the first signal, and M is a positive integer, to obtain the second signal.

33. A communication device, characterized in that, The communication device includes a processing unit and a transceiver unit. The processing unit is coupled to the transceiver unit to execute the method according to any one of claims 1 to 17, or execute the method according to any one of claims 18 to 32.

34. A communication device, characterized in that, The communication device includes a processor coupled to a memory. The memory is used to store a computer program, and the processor is used to execute the computer program stored on the memory, so that the communication device executes the method according to any one of claims 1 to 17, or so that the communication device executes the method according to any one of claims 18 to 32.

35. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program. When the computer program runs on a computer, the computer is caused to execute the method according to any one of claims 1 to 17, or the computer is caused to execute the method according to any one of claims 18 to 32.

36. A computer program product, characterized in that, The computer program product includes a computer program. When the computer program runs on a computer, the computer is caused to execute the method according to any one of claims 1 to 17, or the computer is caused to execute the method according to any one of claims 18 to 32.

37. A chip, characterized in that, The chip includes: A processor and an interface. The processor is used to call and run instructions from the interface. When the processor executes the instructions, the method according to any one of claims 1 to 17 is implemented, or the method according to any one of claims 18 to 32 is implemented.

Images