Wireless device and method for transmitting and receiving signals on wireless communication channel

Abstract

A wireless transmitting device for transmitting a signal over a wireless communication channel. The wireless transmitting device obtains a set of Mu input symbols from a user u and applies a precoder to generate a set of precoded input symbols. The precoder includes a Mu-point discrete affine Fourier transform (DAFT) based on a binary polynomial, the binary polynomial including a first quadratic term of a time index and a second quadratic term of an input symbol index associated with the same coefficient based on a system parameter. The wireless transmission apparatus further applies an inverse N-point discrete affine Fourier transform (IDAFT) to a vector formed by placing the Mu pre-coded input symbols on Mu consecutive entries of an N-long vector, the ranges of the entries allocated to different users not overlapping with each other, and the N is a positive integer greater than or equal to 1, and the N is a positive integer greater than or equal to 2, and the N is a positive integer greater than or equal to 1. The wireless transmission apparatus further applies an inverse N-point discrete affine Fourier transform (IDAFT) to the vector formed by placing the Mu pre-coded input symbols on Mu consecutive entries of the N-long vector. Finally, the wireless transmitting device is configured to transmit the signal on the wireless communication channel with low PAPR performance.

Description

Technical Field

[0001] The present invention generally relates to wireless communication systems, and more particularly to a wireless transmitting device, a wireless receiving device and corresponding methods for transmitting and receiving signals on a wireless communication channel. Background Art

[0002] In general, power amplifiers (e.g., power amplifiers of wireless terminals such as transmitting terminals or receiving terminals) and other devices operating at high carrier frequencies cause nonlinear distortion when transmitting input signals exceeding a certain input power level. Therefore, in this case, it is difficult to achieve high signal-to-noise ratio (SQNR) values ​​when analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) use signals with large peak-to-average power ratios (PAPRs). In addition, in high mobility scenarios such as scenarios where the transmitting terminal or the receiving terminal or both move rapidly relative to each other, the reception of the transmitted signal may be interfered by having relatively large Doppler shift values. In these scenarios, different contributions in the received signal originating from different reflecting and scattering objects in the environment usually have different Doppler shift values ​​when received. The difference between the minimum and maximum Doppler shifts in the received signal is called the Doppler frequency spread. Such wireless channels are time-varying and are called dual-dispersion channels because they involve dispersion both in time (due to delay spread) and in frequency (due to Doppler spread). In existing wireless systems, the greater the Doppler spread, the greater the challenge to data detection at the receiving terminal.

[0003] Traditionally, some attempts have been made to address the data detection challenges at the receiving terminal, for example, by using an orthogonal frequency division multiplexing (OFDM) waveform. However, such OFDM waveforms are not designed for mobility (due to the loss of orthogonality between OFDM subcarriers caused by Doppler shift) nor do they take into account high-frequency impairments (due to the typically poor peak-to-average power ratio (PAPR) performance of OFDM signals, which is not an ideal situation as explained earlier). Therefore, the OFDM waveform can only be tuned to compensate for these effects, for example, by making the OFDM symbols shorter to maintain orthogonality in the presence of Doppler shift. In addition, compensation is not always the best option, as it may result in a loss of spectral efficiency, for example, in the OFDM waveform or other performance indicators. Therefore, there is a technical problem of designing a new waveform that performs better in terms of reliability, achievable data rate or delay, and a larger Doppler frequency spread with improved PAPR performance.

[0004] Therefore, in view of the above discussion, a need exists to overcome the above-mentioned shortcomings associated with conventional approaches for wireless transmitting devices and wireless receiving devices. Summary of the invention

[0005] The present invention provides a wireless transmitting device, a wireless receiving device and a method for sending and receiving signals on a wireless communication channel. The present invention provides a solution to the existing problem, namely how to cope with the challenge of data detection and how to design a new waveform with reduced peak-to-average power ratio (PAPR) performance. The purpose of the present invention is to provide a solution that at least partially overcomes the problems encountered in the prior art and provides an improved wireless transmitting device, an improved wireless receiving device and an improved method for sending and receiving signals on a wireless communication channel. In addition, the signal corresponds to a discrete affine Fourier transform (DAFT) extended affine frequency division multiplexing (AFDM) signal with low peak-to-average power ratio (PAPR) performance. DAFT is a generalization of discrete Fourier transform (DFT) and is a linear transform characterized by several parameters (c1, c2). AFDM is a waveform based on DAFT. The AFDM transmitter uses an inverse discrete affine Fourier transform (IDAFT), which maps the symbols at the input of the AFDM transmitter to a discrete time chirp signal parameterized by (c1, c2) at its output. Each such chirp signal has a phase, which is a bivariate polynomial that includes the first coefficient c1 of the quadratic term of the chirp signal time index n and the second coefficient c2 of the quadratic term of the input symbol index m. AFDM can provide an extension (or coverage) gain that is robust to mobility, carrier frequency offset (CFO), and phase noise. This robustness can be achieved when channel estimation on the receiver side is performed based on a DAFT domain pilot (i.e., based on a reference symbol at the input of the IDAFT module of the AFDM transmitter, which is mapped by the module to a chirp pilot signal to be sent on a wireless channel). Therefore, AFDM is suitable for communications under dual-dispersion channels and high carrier frequencies. However, AFDM has similar PAPR performance to OFDM. DAFT-s-AFDM has better PAPR performance than AFDM and OFDM, while inheriting the advantages of AFDM in communicating under dual-dispersion channels and high carrier frequencies.

[0006] One or more objects of the present invention are achieved by the technical solutions provided in the attached independent claims. Advantageous implementations of the present invention are further defined in the dependent claims.

[0007] In one aspect, the present invention provides a wireless transmission device for transmitting a signal on a wireless communication channel. The wireless transmission device is used to obtain M from a user u. u A set of input symbols, where u∈{1,…,U} and U≥1. In addition, the wireless transmission device is used to u A precoder is applied to a set of input symbols to generate the set of input symbols. The precoder includes an M based on a chirped carrier. u A wireless transmission device is configured to apply an N-point discrete affine Fourier transform (DAFT) to a vector, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of an input symbol index m and a time index n, and the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index. The first quadratic term of the time index and the second quadratic term of the input symbol index are associated with a same coefficient c based on a system parameter. The wireless transmission device is configured to apply an N-point discrete affine Fourier transform (IDAFT) to a vector, wherein the vector is obtained by transforming the M u The preceding input symbols are placed in the Mth of the all-zero N-length vectors u The N-point IDAFT is formed on consecutive entries, and the entry ranges allocated to different users u do not overlap. The N-point IDAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of the precoded input symbol index and the time index. The bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index, and the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, wherein N≥max{M u The wireless transmitting device transmits the signal on the wireless communication channel. u The signal generated by the joint effect of the N-point DAFT and the N-point IDAFT is a single carrier signal with a chirped Dirichlet pulse shape.

[0008] The wireless transmission device is used to transmit a signal, for example, a discrete affine Fourier transform-spread-affine frequency division multiplexing (DAFT-s-AFDM) signal, which is a single carrier signal with a chirped Dirichlet pulse shape. Advantageously, the DAFT-s-AFDM signal has a lower PAPR value compared to traditional methods such as AFDM and OFDM, and is therefore improved. Compared to other traditional single-carrier methods such as DFT-s-OFDM, the DAFT-s-AFDM signal provides orthogonality in the DAFT domain, i.e., when the DAFT transform is applied to the receiver side. In other words, different instances of the wireless transmission device in the wireless communication system can be used to generate a chirped single carrier signal that carries data from multiple user terminals and occupies the same time and frequency resources (due to the chirp), and the signals corresponding to these different users are orthogonally separable at a receiver such as a base station side. In addition, DAFT-s-AFDM provides orthogonal separability between data and DAFT domain reference signals and different DAFT domain reference signals. When transformed to the chirp domain formed by applying the DAFT transform, different DAFT domain reference signals are required for channel estimation and other possible purposes. Therefore, the wireless transmitting device can be used for time-varying channel estimation of DAFT domain pilot symbols in AFDM, etc., because the DAFT-s-AFDM signal inherits the advantages of AFDM in improving the time-varying channel estimation performance and the robustness in the presence of impairments such as CFO.

[0009] In one implementation, the wireless transmission device is used to send an indication of at least one system parameter (eg, a value of N or a DAFT coefficient c) via the signal.

[0010] The indication of the at least one system parameter is used for channel estimation and data detection.

[0011] In another implementation, the wireless transmitting device is configured to form the M by embedding the transform domain pilot symbol into the non-pilot input symbol. u A set of input symbols.

[0012] In this implementation, M u The set of input symbols includes different embedded transform domain pilot symbols and non-pilot input symbols.

[0013] In another implementation, the wireless transmitting device is further configured to form the M by inserting guard samples between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols. u A set of input symbols.

[0014] The guard samples are used to separate each pilot symbol from other pilot symbols, for example, to separate different embedded pilot symbols from each other and to separate embedded pilot symbols from non-pilot input symbols.

[0015] In another implementation, the guard sample has a non-zero value.

[0016] The non-zero values ​​of the guard samples occupy an interval in the time domain and provide low peak-to-average power ratio (PAPR) performance.

[0017] In another aspect, the present invention provides a method for sending a signal on a wireless communication channel. The method comprises obtaining M from a user u. u A set of input symbols, where u∈{1,…,U} and U≥1. In addition, for the M u A precoder is applied to a set of input symbols to generate a set of precoded input symbols, wherein the precoder includes a chirped carrier-based M u A method for generating a signal by applying an N-point discrete affine Fourier transform (DAFT) to a vector, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of an input symbol index and a time index. The bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index, wherein the first quadratic term of the time index and the second quadratic term of the time index are associated with the same coefficient c based on a system parameter and a channel parameter. The method is used to: apply an N-point discrete affine Fourier transform (IDAFT) to a vector to generate the signal, wherein the vector is obtained by dividing the M u The preceding input symbols are placed in the Mth of the all-zero N-length vectors u The N-point IDAFT is formed on consecutive entries, the entry ranges allocated to different users u do not overlap, the N-point IDAFT is based on a chirped carrier, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a precoded input symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, wherein N≥max{M u} u∈{1,…,U} ; sending the signal on the wireless communication channel.

[0018] The method realizes all the advantages and technical effects of the wireless transmitting device of the present invention.

[0019] In another aspect, the present invention provides a wireless receiving device for receiving a signal from a wireless communication channel. The wireless receiving device is used to receive the signal. The signal comes from U user devices, {1, ..., U} and U ≥ 1. The user devices {1, ..., U} are wireless transmitting devices. In addition, the wireless receiving device is used to apply an N-point discrete affine Fourier transform (DAFT) to the N received symbols to generate U sets, wherein each set includes M u DAFT domain symbols. The N-point DAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of a symbol index and a time index. The bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the symbol index. The first quadratic term of the time index and the second quadratic term of the symbol index are associated with the same coefficient c based on a system parameter, wherein N≥max{M u} u∈{1,…,U} The wireless receiving device applies an inverse precoder to each of the sets of DAFT domain symbols to generate a set of estimated input symbols. The inverse precoder includes an M based on a chirp carrier. u A point discrete affine inverse Fourier transform (IDAFT) is performed, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a DAFT domain symbol index and a time index. The bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index. The first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c.

[0020] The wireless receiving device is used to receive a signal, for example, a discrete affine Fourier transform spread affine radio frequency division multiplexing (DAFT-s-AFDM) signal, which is a single carrier signal with a chirped Dirichlet pulse shape. Advantageously, the DAFT-s-AFDM signal has a low PAPR value. The DAFT-s-AFDM signal also provides orthogonality in the DAFT domain, i.e., when the DAFT transform is applied at the receiver side.

[0021] In another aspect, the present invention provides a method for receiving a signal from a wireless communication channel. The method comprises receiving the signal, wherein the signal comprises M for each user u. u There are U sets of received symbols, where u∈{1,…,U} and U≥1. In addition, for the M u The aggregation of U sets of received symbols applies an N-point discrete affine Fourier transform (DAFT) to generate U sets, where each set includes M uDAFT domain symbols, the N-point DAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of a symbol index and a time index. The bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the symbol index. The first quadratic term of the time index and the second quadratic term of the symbol index are associated with the same coefficient c based on system parameters and channel parameters, wherein N≥max{M u} u∈{1,…,U} Applying an inverse precoder to each of the sets of DAFT domain symbols to generate U sets of estimated symbols. The inverse precoder includes an M chirp carrier-based u A point discrete affine inverse Fourier transform (IDAFT) is performed, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a DAFT domain symbol index and a time index, wherein the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index. The first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c.

[0022] The method realizes all the advantages and technical effects of the wireless receiving device of the present invention.

[0023] It should be understood that all of the above implementations may be combined.

[0024] It should be noted that all devices, elements, circuits, units and devices described in this application can be implemented in software or hardware elements or any type of combination thereof. All steps performed by various entities described in this application and the functions to be performed by various entities described are intended to indicate that the corresponding entities are suitable for or used to perform the corresponding steps and functions. Although in the description of the following specific embodiments, the specific functions or steps to be performed by external entities are not reflected in the description of the specific detailed elements of the entity that performs the specific steps or functions, it should be clear to the technician that these methods and functions can be implemented in the corresponding software or hardware elements or any type of combination thereof. It should be understood that the features of the present invention are easy to combine in various combinations without departing from the scope of the present invention defined by the appended claims.

[0025] Other aspects, advantages, features and objects of the present invention will become apparent from the accompanying drawings and detailed description of illustrative implementations interpreted in conjunction with the following appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above summary of the invention and the detailed description of the following illustrative embodiments can be better understood by reading in conjunction with the accompanying drawings. In order to illustrate the present invention, exemplary structures of the present invention are shown in the accompanying drawings. However, the present invention is not limited to the specific methods and tools disclosed herein. In addition, it should be understood by those skilled in the art that the accompanying drawings are not drawn to scale. Where possible, the same elements are represented by the same numbers.

[0027] Embodiments of the present invention will now be described by way of example only with reference to the following drawings, in which:

[0028] Figure 1A is a schematic diagram of a network environment of a wireless communication system according to an embodiment of the present invention;

[0029] Figure 1B and Figure 1C is a different block diagram showing a wireless transmitting device and a wireless receiving device according to one embodiment;

[0030] Figure 2A is a schematic diagram showing a wireless transmission device sending a signal through a wireless communication channel according to an embodiment;

[0031] Figure 2B is a schematic diagram showing a wireless transmission device sending a signal through a wireless communication channel according to another embodiment;

[0032] Figure 3A is a schematic diagram illustrating transform domain (embedded) pilot symbols and guard samples according to one embodiment;

[0033] Figure 3B is a schematic diagram illustrating DAFT domain (non-embedded) pilot symbols and guard samples according to one embodiment;

[0034] Figure 4 is a flow chart illustrating a method for transmitting a signal over a wireless communication channel according to one embodiment;

[0035] Figure 5A is a schematic diagram illustrating a wireless receiving device for receiving a signal from a wireless communication channel according to one embodiment;

[0036] Figure 5B is a schematic diagram showing a wireless receiving device for receiving a signal from a wireless communication channel according to another embodiment;

[0037] Figure 6 is a flow chart illustrating a method for receiving a signal on a wireless communication channel according to one embodiment.

[0038] In the drawings, underlined numbers are used to indicate the item in which the underlined number is located or an item adjacent to the underlined number, and non-underlined numbers are associated with the item identified by the line associating the non-underlined number with the item. When a number is not underlined and has an associated arrow, the non-underlined number is used to identify the general item to which the arrow points. DETAILED DESCRIPTION

[0039] The following detailed description describes embodiments of the invention and ways in which these embodiments may be implemented. Although some modes of implementing the invention have been disclosed, those skilled in the art will recognize that there may be other embodiments for implementing or practicing the invention.

[0040] Figure 1A FIG. 1 is a schematic diagram of a network environment of a wireless communication system according to an embodiment of the present invention. Figure 1A , shows a network environment of a wireless communication system 100A, which includes a wireless transmission device 102 and a wireless reception device 104. A wireless communication channel 106 is also shown.

[0041] The wireless communication system 100A includes a wireless transmission device 102, a wireless receiving device 104, and a wireless communication channel 106. The wireless transmission device 102 is used to send one or more signals to the wireless receiving device 104 through the wireless communication channel 106. The transmitter device 102 is a user terminal that transmits on the uplink. In addition, U transmitter devices are used in the uplink, each transmitter device includes M u Examples of wireless transmission device 102 include, but are not limited to, a transmitter, a transmitter, a transceiver, an encoder, a user terminal of a cellular network, custom hardware for wireless communication, a transmitter, or any other portable or non-portable electronic device.

[0042] The wireless receiving device 104 is used to receive signals from the wireless transmitting device 102 through the wireless communication channel 106. Examples of the wireless receiving device 104 may include, but are not limited to, a receiver, a decoder, a transceiver, a base station or an access point in a cellular network, and the like.

[0043] The wireless communication channel 106 includes a medium (e.g., a communication channel) through which one or more transmitting devices (e.g., the wireless transmitting device 102) potentially communicate with the wireless receiving device 104. Examples of the wireless communication channel 106 may include, but are not limited to, a cellular network, a wireless sensor network (WSN), a cloud network, a local area network (LAN), a vehicle-to-network (V2N) network, a metropolitan area network (MAN), etc.

[0044] The wireless transmission device 102 (also referred to herein as the device 102) is used to obtain M from the user u. u A set of input symbols, where u∈{1,…,U} and U≥1. The wireless transmitting device 102 is used to u The precoder is applied to a set of input symbols to generate a set of precoded input symbols. The precoder includes a chirped carrier-based M u The phase of each chirp carrier in the chirp carrier is a bivariate polynomial of the input symbol index m and time index n. Therefore, when M is fed into the input of the precoder u Symbols When the precoder generates M at its output u Samples In addition, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index, such that In addition, the first quadratic term of the time index and the second quadratic term of the input symbol index are associated with the same coefficient c based on the system parameters (i.e., c1=c2=c). Thereafter, the wireless transmission device 102 is configured to apply an N-point discrete affine Fourier inverse transform (IDAFT) to the vector, wherein the vector is obtained by dividing the M u The precoded input symbols are placed in the Mth N-length vector of all zeros. u The N-point IDAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of the precoding input symbol index m and time index n. The bivariate polynomial includes a first quadratic term for the time index and a second quadratic term for the precoded input symbol index. Therefore, when an N-length vector is fed into the input of the N-point IDAFT The N-point IDAFT produces N samples at its output Furthermore, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c1=c2=c, where N≥max{M u} u∈{1,…,U} In one example, the coefficient c is equal to Thereafter, the wireless transmitting device 102 is used to transmit a signal to another user (eg, the wireless receiving device 104 ) on the wireless communication channel 106 .

[0045] The wireless receiving device 104 (also referred to herein as device 104) is configured to receive a signal from a wireless communication channel 106. The wireless receiving device 104 is configured to receive signals from U user devices, such as the wireless transmitting device 102, {1, ..., U} and U ≥ 1. In one example, one or more user devices are configured to provide multiple non-overlapping inputs to their corresponding N-point IDAFT modules (e.g., AFDM modulators), and each user input is precoded before being fed into the N-point IDAFT. Thereafter, the wireless receiving device 104 is configured to apply an N-point discrete affine Fourier transform (DAFT) to the N received symbols to generate U sets, wherein each set includes M u DAFT domain symbols. In addition, the N-point DAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of the symbol index and the time index, and the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the symbol index. In addition, the first quadratic term of the time index and the second quadratic term of the symbol index are associated with the same coefficient c based on the system parameter, where N≥max{M u} u∈{1,…,U} . M u The signal generated by the combined effect of the N-point DAFT and the N-point IDAFT is a single carrier signal with a chirped Dirichlet pulse shape. Thereafter, the wireless receiving device 104 is configured to apply an inverse precoder to each of the sets of DAFT domain symbols to generate a set of estimated input symbols. In addition, the inverse precoder includes an M-based chirped carrier. uPoint discrete affine inverse Fourier transform (IDAFT), the phase of each chirp carrier in the chirp carrier is a bivariate polynomial of the DAFT domain symbol index and the time index. In addition, the bivariate polynomial includes the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index. In addition, the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c. DAFT is a generalization of the discrete Fourier transform (DFT) and is a linear transform characterized by several parameters (c1, c2). AFDM is a DAFT-based waveform. The AFDM transmitter uses a discrete affine inverse Fourier transform (IDAFT), which maps the symbols at the input of the AFDM transmitter to a discrete time chirp signal parameterized by (c1, c2) at its output. Each such chirp signal has a phase, which is a bivariate polynomial, which includes the first coefficient c1 of the quadratic term of the chirp signal time index n and the second coefficient c2 of the quadratic term of the input symbol index m. AFDM can provide an extension (or coverage) gain that is robust to mobility, carrier frequency offset (CFO), and phase noise. This robustness can be achieved when channel estimation on the receiver side is performed based on a DAFT domain pilot (i.e., based on a reference symbol at the input of the IDAFT module of the AFDM transmitter, which is mapped by the module to a chirped pilot signal to be sent on the wireless channel). Therefore, AFDM is suitable for communications under dual-dispersion channels and high carrier frequencies. However, AFDM has a PAPR performance similar to that of OFDM. DAFT-s-AFDM has better PAPR performance than AFDM and OFDM, while inheriting the advantage of AFDM in communicating under dual-dispersion channels and high carrier frequencies.

[0046] The wireless transmitting device 102 and the wireless receiving device 104 in the wireless communication system 100A provide an improved AFDM signal or waveform for a dual-dispersion channel, which can be used to generate a multi-chirp signal characterized by multiple tunable parameters. The AFDM signal can achieve full diversity of a linear time-varying (LTV) channel with low pilot overhead. The wireless communication system 100A also provides an improved AFDM waveform and transceiver design, namely DAFT extended AFDM (i.e., DAFT-s-AFDM), so that the advantages of AFDM can be achieved with improved peak-to-average power ratio (PAPR) performance. In other words, the wireless communication system 100A is used to provide a DAFT-s-AFDM signal for low PAPR wireless transmission.

[0047] Figure 1B and Figure 1C 2 is a block diagram showing different wireless transmission devices and wireless receiving devices according to an embodiment of the present invention. Figure 1B, shows a block diagram 100B of a wireless transmission device 102, the wireless transmission device 102 including a first processor 108, a first communication interface 110 and a first memory 112. Figure 1C , shows a block diagram 100C of a wireless receiving device 104 , which includes a second processor 114 , a second communication interface 116 , and a second memory 118 .

[0048] The wireless transmitting device 102 uses the first communication interface 110 to communicate with the wireless receiving device 104 through the wireless communication channel 106. In addition, the wireless receiving device 104 uses the second communication interface 116 to communicate with the wireless transmitting device 102 through the wireless communication channel 106. Examples of implementations of the first communication interface 110 and the second communication interface 116 may include, but are not limited to: a network interface, a computer port, a network socket, a network interface controller (NIC), and any other network interface device.

[0049] The first processor 108 is used to send signals from the wireless transmission device 102 through the wireless communication channel 106. In addition, the second processor 114 is used to receive signals from the wireless transmission device 102 through the wireless communication channel 106. Examples of implementations of the first processor 108 and the second processor 114 may include, but are not limited to: a central data processing device, a microprocessor, a microcontroller, a complex instruction set computing (CISC) processor, an application-specific integrated circuit (ASIC) processor, a reduced instruction set (RISC) processor, a very long instruction word (VLIW) processor, a state machine, and other processors or control circuits.

[0050] The first memory 112 and the second memory 118 are used to store M uThe first memory 112 and the second memory 118 may be implemented in an example including, but not limited to, an electrically erasable programmable read-only memory (EEPROM), a dynamic random access memory (DRAM), a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a flash memory, a secure digital (SD) card, a solid-state drive (SSD), and / or a CPU cache.

[0051] Figure 2A FIG. 1 is a schematic diagram showing a wireless transmission device sending a signal through a wireless communication channel according to an embodiment. Figure 1A and Figure 1B The elements in describe Figure 2A . refer to Figure 2A , shows a schematic diagram 200A, including a series of operations from 202 to 212. The wireless transmission device 102 ( Figure 1A ) is used to perform the operations shown in schematic diagram 200A.

[0052] In operation, the wireless transmission device 102 (hereinafter referred to as the device 102) is used to obtain M from the user u. u A set of input symbols, where u∈{1,…,U} and U≥1. For example, at operation 202, the wireless transmitting device 102 is used to obtain M from user u. u In one implementation, M u The set of input symbols may be obtained from different users, for example, user 1, user 2, or user U. In one example, user u may also include a user for transmitting M to the wireless transmitting device 102. u A device that accepts a collection of input symbols.

[0053] According to one embodiment, the wireless transmitting device 102 is further configured to form M by embedding the transform domain pilot symbol into the non-pilot input symbol. u For example, at operation 204, the wireless transmitting device 102 is configured to embed the transform domain pilot symbol into the non-pilot input symbol (eg, input symbol) to form M u is a set of input symbols. Therefore, M uThe set of input symbols includes different embedded transform domain pilot symbols and non-pilot input symbols (e.g., input symbols). According to another embodiment, the wireless transmitting device 102 is further configured to form M by inserting guard samples between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols. u In one example, the wireless transmitting device 102 uses the first processor 108 to insert guard samples between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols, such as Figure 3A As further shown. The guard samples are used to separate each pilot symbol from other pilot symbols, for example, to separate different embedded pilot symbols from each other and to separate embedded pilot symbols from non-pilot input symbols. In one example, the guard samples can also be used as a protection measure for the embedded pilot symbols to protect them from interference, etc. Therefore, the guard samples are used to prevent interference between two different pilot symbols. In such an embodiment, the guard samples have a non-zero value. Therefore, the guard samples can also be referred to as constant amplitude samples, which can occupy an interval in the time domain and provide low peak-to-average power ratio (PAPR) performance.

[0054] The wireless transmission device 102 is also used to u A set of input symbols is subjected to a precoder to generate a set of precoded input symbols, wherein the precoder includes a chirped carrier-based M u The phase of each chirp carrier in the chirp carrier is a bivariate polynomial of the input symbol index m and the time index n. For example, at operation 206, the wireless transmission device 102 is used to perform M u The set of input symbols M u Point DAFT to generate a set of precoded input symbols, where M u Point DAFT is based on chirped carriers, where the phase of each chirped carrier is a bivariate polynomial p(m,n) of the input symbol index m and time index n. u Feed M at the input of DAFT u Symbols When M u The point DAFT produces M at its output u Samples In one implementation, the wireless transmission device 102 is configured to utilize a precoder that provides an improved peak-to-average power ratio (PAPR) value. In addition, the bivariate polynomial includes a first quadratic term with a time index n and a second quadratic term with an input symbol index m. In addition, the first quadratic term with a time index n and the second quadratic term with an input symbol index m are associated with the same coefficient c based on a system parameter. In one example, the first quadratic term with a time index n is associated with a coefficient c1, the second quadratic term with an input symbol index m is associated with a coefficient c2, and c1=c2=c (i.e., the same coefficient), such that

[0055] According to one embodiment, the wireless transmitting device 102 is further configured to: u The pilot symbols are placed at the input of the N-point IDAFT vector R u On consecutive entries, add R to the send signal u A set of DAFT domain pilot symbols, where R u consecutive entries with M u The entries occupied by the output of the point DAFT do not overlap. For example, at operation 208, the wireless transmission device 102 is used to: u The pilot symbols are placed at the input of the N-point IDAFT vector R u consecutive entries, where the R u consecutive entries with M u The output of the DAFT point (ie, M u The entries occupied by point (c, c) DAFT) do not overlap, and R is added to the transmitted signal u In this embodiment, the wireless transmitting device 102 is further configured to: insert guard samples between predefined symbols to form R u A set of additional DAFT domain pilot symbols is added and guard samples are inserted into the vector at the input of the N-point IDAFT, where the input of the N-point IDAFT is located at M u The set of precoded input symbols and R u In one implementation, multiple inputs of the N-point IDAFT (i.e., IDAFT module) may be dedicated to transmitting A set of pilot symbols In one example, a subset The modulus of the number Np, u (Right now ) corresponds to the number of guard samples required for channel estimation at the receiver side such as the wireless receiving device 104. In one example, since such pilot symbols are not embedded in data symbols in the transform domain, such pilot symbols may be referred to as "non-embedded pilot symbols". Since such pilot symbols are directly fed into the N-point IDAFT (i.e., the IDAFT module) and are therefore located in the DAFT domain, such pilot symbols may also be referred to as "DAFT domain pilot symbols".

[0056] The wireless transmitting device 102 is further configured to apply an N-point discrete affine inverse Fourier transform (IDAFT) to the vector, wherein the vector is obtained by transforming M u The precoded input symbols are placed in the Mth N-length vector of all zeros. u The ranges of entries allocated to different users u do not overlap. First, the wireless transmission device 102 is used to u The precoded input symbols are placed in the Mth N-length vector of all zeros. u consecutive entries to form a vector, wherein the ranges of entries assigned to different users u do not overlap. Thereafter, at operation 210, the wireless transmission device 102 is further configured to apply an N-point IDAFT to the vector. In addition, the N-point IDAFT is based on a chirped carrier, and the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of the precoded input symbol index and the time index, and the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index. In addition, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, wherein N≥max{M u} u∈{1,…,U} .

[0057] According to one embodiment, the wireless transmitting device 102 is further configured to: after applying the N-point IDAFT to generate the signal, append a chirp period prefix or a cyclic prefix to the signal. u The signal produced by the combined effect of the 1-point DAFT and the N-point IDAFT is a single carrier signal with a chirped Dirichlet pulse shape. The chirped periodic prefix is ​​known in the art of chirped waveforms and plays a similar role in AFDM signals as the cyclic prefix does in OFDM signals, where the chirped carrier The frequency of increases or decreases over time. The cyclic prefix corresponds to a specific type of chirp period prefix with a defined condition (i.e., if 2Nc is an integer). For example, at operation 212, when (thus 2Nc is an integer value), the wireless transmitting device 102 is configured to perform time-domain cyclic prefix (CP) insertion at the output of the N-point (c, c) IDAFT in operation 210 .

[0058] In one implementation, by uconsecutive entries (e.g., M u data symbols) are fed to M u precoded input symbols (eg, M u consecutive inputs) to form a vector of all zeros N-long vector (e.g., a subset of {0, ..., N-1} ), to obtain signals from users, where the entry ranges assigned to different users u do not overlap.

[0059] In addition, the wireless transmission device 102 is configured to apply an N-point IDAFT to the vector, for example, at operation 210. In one example, the N-point IDAFT is also referred to as an N-point (c1, c2) IDAFT, which is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of the precoded input symbol index and the precoded time index, for example, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index. In addition, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, where N≥max{M u} u∈{1,…,U} In other words, the N-point IDAFT is configured with c1 = c2 = c and fed with all-zero inputs, except for the M u A collection of input symbols or data symbols is M u M generated by DAFT domain precoding at point (c,c) u precoded input symbols (eg, M u Continuous inputs), as shown in operation 206. In one example, if The wireless transmission device 102 is used to generate a discrete affine Fourier transform-spread AFDM (DAFT-s-AFDM) signal or waveform as shown in the following equation (1).

[0060]

[0061] The above equation can be simplified and rewritten into the new equation (2) as shown below.

[0062]

[0063] Among them, for some integer P>1, N=PM u , and is defined as a Dirichlet pulse. In addition, since the Dirichlet pulse g k The decay curve of In, n The transform domain samples are converted to approximately Continuous time-domain valid samples.

[0064] In addition, the wireless transmission device 102 is configured to generate a signal having a lower peak-to-average power ratio (PAPR) performance than the AFDM signal shown in equation (3).

[0065]

[0066] In other words, the PAPR performance of the DAFT-s-AFDM signal is reduced. In addition, the DAFT-s-AFDM signal is a single carrier signal with a chirped Dirichlet pulse shape. Since the chirped pulse only affects the phase of the time domain samples and does not affect the PAPR performance, the DAFT-s-AFDM signal has a PAPR performance comparable to that of the signal of the conventional DFT-s-OFDM waveform shown in equation (4).

[0067]

[0068] Where k = 0, ..., N-1, for some integer P>1, N = PM u ,and is the Dirichlet pulse.

[0069] In other words, the PAPR performance of the DAFT-s-AFDM signal is better than the PAPR performance of the OFDM signal and the AFDM signal. In one implementation, it is usually necessary to add Np, u ≥ 1 pilot symbol, and M u A set of input symbols or data symbols is used to perform pilot-based channel estimation at a receiver such as a wireless receiving device 104. u The set of input symbols is embedded into the pilot symbol, so that The cardinality Np, u The subset consists of pilot symbols corresponding to the transform domain embedded pilot symbols. Thereafter, the wireless transmission device 102 is used to send a signal on the wireless communication channel 106. In one example, the signal includes transform domain pilot symbols. In another example, the signal includes DAFT domain (i.e., non-embedded) pilot symbols. In addition, the DAFT domain pilot can take advantage of the fact that the DAFT domain provides an improved delay-Doppler representation of the time-varying channel response compared to the time domain and the frequency domain. In the former domain, channel paths with similar delay values ​​but different Doppler shifts are separated from channel paths with similar Doppler shift values ​​but different delays, thereby improving the channel estimation performance. This feature of AFDM and DAFT-s-AFDM with DAFT domain pilots can be translated into lower pilot overhead, thereby achieving higher spectral efficiency.

[0070] In one implementation, the wireless transmitting device 102 provides a robust extension / coverage gain in the presence of high frequency impairments. In this implementation with DAFT domain (i.e., non-embedded) pilot symbols, the DAFT-s-AFDM signal inherits another advantage of AFDM, such as improved extension / coverage gain that is robust in the presence of carrier frequency offset (CFO) and phase noise (PN). Consider an N-point AFDM signal or a DAFT-s-AFDM signal in M u ≤NDAFT chirp transmission from / to user equipment u. When coupled with DAFT domain pilots, such transmissions include (virtual) M u Larger subcarrier spacing for OFDM transmission Improved robustness of the DAFT, as opposed to smaller subcarrier spacing related to the size N of the underlying transform (i.e., N-point DAFT) This property contrasts with OFDM and DFT-s-OFDM, where the robustness of OFDM and DFT-s-OFDM is determined by the size N of the underlying DFT rather than by the number of occupied subcarriers M. u In addition, due to the improved robustness, N-point DAFT-s-AFDM with larger N values ​​can be used for high-frequency channels in power-limited scenarios, resulting in an increase in the effective signal-to-interference-plus-noise ratio (SINR) of each data symbol. (i.e., coverage gain of device u In addition, the remaining chirp carriers (eg, NM u ) can be used to multiplex data symbols from other devices (i.e. without losing overall spectral efficiency).

[0071] In one implementation, the wireless transmitting device 102 is first used to perform digital-to-analog conversion and up-conversion on a signal such as a DAFT-s-AFDM signal, and then serially transmit the signal to other users such as a wireless receiving device 104 on a wireless communication channel 106. According to one embodiment, the wireless transmitting device 102 is also used to transmit an indication of at least one system parameter (e.g., a value of N or a DAFT coefficient c) through a signal such as a DAFT-s-AFDM signal. In one implementation, the at least one system parameter may correspond to a chirp rate parameter c or an N-frame size (i.e., an N-size frame). Optionally, the chirp rate corresponds to a frequency change rate of a chirp carrier constituting the signal, and the N-frame corresponds to a frequency change rate of a chirp carrier constituting the signal, and the N-frame corresponds to a frequency change rate of a chirp carrier constituting the signal. u In one example, the time index n is related to the sampling rate (e.g., T s ), so the duration of the N-long frame cannot exceed N times the sampling rate (i.e., NT s), and the frequency of the chirp carrier cannot exceed 1 / T s In addition, the indication of at least one system parameter is used for channel estimation and data detection at a receiver such as the wireless receiving device 104 .

[0072] The wireless transmitting device 102 is used to transmit a signal, for example, a DAFT-s-AFDM signal, which is a single carrier signal with a chirped Dirichlet pulse shape. Advantageously, the DAFT-s-AFDM signal has a lower PAPR value and is therefore better than conventional methods such as AFDM and OFDM. Compared with other conventional single carrier methods such as DFT-s-OFDM, the DAFT-s-AFDM signal provides orthogonality in the DAFT domain, i.e., when the DAFT transform is applied to the receiver side such as the wireless receiving device 104. In other words, different instances of the wireless transmitting device 102 in the wireless communication system 100A can be used to generate a chirped single carrier signal that carries data from multiple user terminals and occupies the same time and frequency resources (due to the chirp), and the signals corresponding to these different users are orthogonally separable at the receiver such as the base station side. In addition, DAFT-s-AFDM provides orthogonal separability between data and DAFT domain reference signals and different DAFT domain reference signals. When transformed to the chirp domain formed by applying the DAFT transform, different DAFT domain reference signals are needed for channel estimation and other possible purposes. Therefore, the wireless transmitting device 102 can be used for time-varying channel estimation of DAFT domain pilot symbols in AFDM, etc., because the DAFT-s-AFDM signal inherits the advantages of AFDM in improving the time-varying channel estimation performance and the robustness in the presence of impairments such as CFO.

[0073] Figure 2B FIG. 1 is a schematic diagram showing a wireless transmission device sending a signal through a wireless communication channel according to another embodiment. Figure 1A , Figure 1B and Figure 2A The elements in describe Figure 2B . refer to Figure 2B , shows a schematic diagram 200B, including a series of operations from 214 to 226. The wireless transmission device 102 ( Figure 1A ) is used to perform the operations shown in the schematic diagram 200B without explicitly using the DAFT / IDAFT module.

[0074] The DAFT-s-AFDM signal given by equations (1) and (2) can be viewed as a chirped version of the DFT-s-OFDM signal with chirped input data symbols given by equation (4). Therefore, the following DFT-s-OFDM modulator-based implementation can be used to generate the DAFT-s-AFDM signal. At operation 214, the wireless transmitting device 102 is used to obtain M from user u. u Thereafter, at operation 216, the wireless transmission device 102 is configured to perform transform domain pilot insertion, for example, inserting into non-pilot input symbols. In addition, at operation 218, the wireless transmission device 102 is configured to perform transform domain pilot insertion by using a complex exponential etc., among which, And m u Corresponds to The minimum index of the precoded input symbol index in the set, for the input symbol Chirp to get M u The set of chirp input symbols Thereafter, the wireless transmitting device 102 is used to transmit M u The chirped input symbols are placed in the Mth of an N-length vector of all zeros. u In addition, at operation 220, the wireless transmission device 102 is used to transmit M u The chirped input symbols are fed into a set of indices corresponding to the N-point DFT-s-OFDM In addition, at operation 222, the wireless transmission device 102 is used to apply a chirp (eg, γ n chirp), so the DAFT-s-AFDM signal is the DFT-s-OFDM signal in equation (4) Perform time domain chirping (e.g., by using a complex exponential in,

[0075] Optionally, at operation 224, the wireless transmitting device 102 is configured to perform DAFT domain pilot insertion by adding chirp in the time domain, for example, in, is the DAFT index m∈R uThe value of the DAFT domain pilot symbol at . In addition, at operation 226, the wireless transmission device 102 is used to perform a time domain cyclic prefix (CP) insertion at the DAFT-s-AFDM signal. Therefore, the DAFT-s-AFDM signal or waveform can be regarded as a chirped DFT-s-OFDM signal with chirped input data symbols. In other words, a DAFT-s-AFDM signal can be generated without an IDAFT / DAFT module, and the signal is also sent to the wireless communication channel 106. In one implementation, the DAFT-s-AFDM signal of the wireless transmission device 102 (i.e., the transceiver) has backward compatibility and is compatible with traditional wireless systems such as the wireless communication system 100A. In one example, due to the absence of the IDAFT module, the wireless transmission device 102 cannot directly access the DAFT domain. Therefore, if a transmission DAFT domain (i.e., non-embedded) pilot symbol insertion is required, it can be performed by adding the time domain samples to the time domain samples of the data portion of the DAFT-s-AFDM signal.

[0076] In one implementation, for each terminal u∈{1,…,U}, the wireless transmission device 102 is used to set the signal (eg, data) and any possible pilot symbols that may be embedded with the signal into a frame. In addition, each frame includes M u A set of input symbols and feeding the samples to the N-point DFT-s-OFDM modulator Before the input defined by the index in , convert the sample to a complex exponential Multiply, where Thereafter, the wireless transmitting device 102 may be configured to add a single N-long chirp, each chirp corresponding to a non-embedded DAFT domain pilot symbol, the chirp parameter of the pilot symbol being derived from the number of pixels occupied by the pilot symbol. In addition, a cyclic prefix (CP) is used to supplement the M at the output of the N-point DFT-s-OFDM modulator. u The set of input symbols and the N+L samples at the output of the modulator are compared with the complex exponential Multiply, where

[0078] Figure 3A FIG. 1 is a schematic diagram showing a transform domain (embedded) pilot symbol and guard samples according to one embodiment. Figures 1A to 2B The elements in describe Figure 3A . refer to Figure 3A , shows a schematic diagram 300A of transform domain pilot symbols and guard samples represented in transform (i.e., input to point precoder, domain and time domain). Also shown is M including transform domain pilot and guard samples and non-pilot symbols uA set 302 of precoded input symbols, and a discrete affine Fourier transform-spread AFDM (DAFT-s-AFDM) signal 304 in the time domain, the range of which is occupied by time domain samples corresponding to transform domain pilot and guard samples.

[0079] refer to Figure 3A , showing the insertion of guard samples between different transform domain pilot symbols to form M u A set of input symbols. In one implementation, guard samples are inserted between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols. In one example, the wireless transmission device 102 uses the first processor 108 to insert guard samples between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols. The guard samples are used to separate each pilot symbol from other pilot symbols, for example, to separate different transform domain pilot symbols. Therefore, the guard samples are used to prevent interference between two different transform domain pilot symbols. In such an embodiment, the guard samples have a non-zero value, and the guard samples may also be referred to as non-zero guard samples. Therefore, the guard samples may also be referred to as constant amplitude samples away from zero samples.

[0080] Also shown is a representation of the DAFT-s-AFDM signal 304 in the time domain. In addition, the guard samples may occupy intervals in the time domain of the DAFT-s-AFDM signal 304 and may provide low peak-to-average power ratio (PAPR) performance, such as Figure 3A In one implementation, the wireless transmitting device 102 is configured to: after applying N-point IDAFT to generate a DAFT-s-AFDM signal 304 based on a vector, append a chirp period prefix or a cyclic prefix to the DAFT-s-AFDM signal 304 (or a transmitting signal), wherein the vector is obtained by replacing M u The preceding input symbols are placed in the Mth of the all-zero N-length vectors u The DAFT-s-AFDM signal 304 includes a time domain cyclic prefix (CP), such as Figure 3A shown.

[0081] Figure 3B FIG. 1 is a schematic diagram showing DAFT domain (non-embedded) pilot symbols and guard samples according to one embodiment. Figures 1A to 2B The elements in describe Figure 3B . refer to Figure 3B , showing a schematic diagram 300B of DAFT domain pilot symbols and guard samples. Also shown is M u A set 306 of precoded input symbols and a discrete affine Fourier transform-spread AFDM signal 308 are provided.

[0082] According to one embodiment, the wireless transmitting device 102 is used to: u The pilot symbols are placed at the input of the N-point IDAFT vector R u On consecutive entries, add R to the send signal u A set of DAFT domain pilot symbols, where R u The consecutive entries do not overlap with the entries occupied by the output of the Mu-point DAFT. In this embodiment, the wireless transmitting device 102 is further configured to: insert guard samples between predefined symbols to form R u A set of additional DAFT domain pilot symbols is added and guard samples are inserted into the vector at the input of the N-point IDAFT, where the input of the N-point IDAFT is located at M u The set 306 of precoded input symbols and R u Between the sets of additional DAFT domain pilot symbols, such as Figure 3B In one implementation, one or more inputs of the N-point IDAFT (i.e., IDAFT module) may be dedicated to sending A set of pilot symbols In one example, a subset The modulus of the number Np, u (Right now ) is the number of protection samples required for channel estimation on the receiver side such as the wireless receiving device 104. Therefore, since the data symbols in the transform domain are not embedded, this pilot symbol is called a "non-embedded pilot symbol". Since it is directly fed into the N-point IDAFT (i.e., the IDAFT module), this pilot symbol is also called a "DAFT domain pilot symbol". In such an embodiment, the wireless transmitting device 102 is also used to: after applying the N-point IDAFT to generate the signal, append a chirp period prefix or a cyclic prefix to the transmit signal (e.g., the DAFT-s-AFDM signal 308). In addition, the time domain samples of the DAFT-s-AFDM signal 308 correspond to the sum of the chirped single carrier signal (i.e., the data portion of the DAFT-s-AFDM signal 308) and one or more chirp signals, each chirp signal corresponding to a DAFT domain pilot symbol. Therefore, the time domain samples of the DAFT domain pilot symbol are as follows: Figure 3B As shown, to occupy the entire time range of signal 308.

[0083] Figure 4 is a flow chart showing a method for sending a signal over a wireless communication channel according to one embodiment. Figures 1A to 3B The elements in describe Figure 4 . refer to Figure 4 , showing a method for transmitting data in a wireless communication channel 106 ( Figure 1AFlow chart of method 400 for sending a signal on a wireless transmission device 102 ( Figure 1A ) is used to execute method 400.

[0084] The method 400 is for transmitting a signal over a wireless communication channel 106. The signal corresponds to a discrete affine Fourier transform (DAFT) spread AFDM signal with low peak-to-average power ratio (PAPR) performance for wireless transmission with an improved AFDM waveform for dual dispersion channels.

[0085] At step 402, method 400 includes: obtaining M from a user u A set of input symbols, where u∈{1,…,U} and U≥1. The wireless transmitting device 102 ( Figure 1A (in Chinese) is used to obtain M from the user u According to one embodiment, in order to obtain M u The method 400 includes: obtaining input symbols from a user equipment and embedding transform domain pilot symbols into the input symbols to form corresponding M u The wireless transmitting device 102 is used to obtain M from a user equipment u A set of input symbols (eg, non-pilot input symbols) is then used to embed the transform domain pilot symbols into the received input symbols to form the corresponding M u is a set of input symbols. Therefore, M u The set of input symbols includes different embedded transform domain pilot symbols and received input symbols. According to one embodiment, the method 400 further includes: inserting a guard sample between two symbols into the corresponding M u For example, the wireless transmitting device 102 is further configured to insert the guard samples between the transform domain pilot symbol and the received input symbol into the corresponding M u The guard samples are used to separate each symbol from other symbols, for example, to separate different embedded pilot symbols from each other. In such an embodiment, the guard samples include non-zero values. Therefore, the guard samples may also be referred to as constant amplitude samples, which may occupy an interval in the time domain and provide low peak-to-average power ratio (PAPR) performance.

[0086] At step 404, method 400 includes: u Applying a precoder to each input symbol in a set of input symbols to generate U sets of precoded input symbols, wherein the precoder includes M based on a chirped carrier. uThe point - discrete affine Fourier transform (DAFT), where the phase of each chirp carrier in the chirp carrier is a binary polynomial of the input symbol index and the time index. Further, the binary polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index. The first quadratic term of the time index and the second quadratic term of the time index are associated with the same coefficient c based on system parameters. The wireless transmitting device 102( Figure 1A in) is used to apply an M u - point DAFT to a set of M u input symbols to generate a set of precoded input symbols based on a binary polynomial of the input symbol index m and the time index n. In one example, the first quadratic term of the time index n is associated with the coefficient c1, the second quadratic term of the input symbol index m is associated with the coefficient c2, and c1 = c2 = c.

[0087] According to one embodiment, method 400 further includes: appending a set of R u DAFT - domain pilot symbols to the transmitted signal by placing R u pilot symbols on R u consecutive entries of a vector at the input of an N - point IDAFT, where the R u consecutive entries do not overlap with the entries occupied by the output of an M - point DAFT. The wireless transmitting device 102( Figure 1A in) is used to: append a set of R u DAFT - domain pilot symbols to the transmitted signal (i.e., perform DAFT - domain pilot insertion) by placing R u pilot symbols on R u consecutive entries of a vector at the input of an N - point IDAFT, where the R u consecutive entries do not overlap with the entries occupied by the output of an M u - point DAFT (i.e., an M u - point (c,c) DAFT). In such an embodiment, method 400 further includes: inserting guard samples between predefined symbols to form a set of R u additional DAFT - domain pilot symbols, and inserting guard samples in the vector at the input of the N - point IDAFT, where the input of the N - point IDAFT is located between a set of M u precoded input symbols and a set of R u additional DAFT - domain pilot symbols. The wireless transmitting device 102( Figure 1A in) is used to insert guard samples between predefined symbols. In one example, since the data symbols are not embedded in the transform domain, such pilot symbols can be referred to as "non - embedded pilot symbols". Since they are directly fed into the N - point IDAFT (i.e., the IDAFT module), such pilot symbols can also be referred to as "DAFT - domain pilot symbols".

[0088] At step 406, the method 400 further includes: applying an N-point discrete affine inverse Fourier transform (IDAFT) to the vector to generate a signal, wherein the vector is obtained by dividing the M u The precoded input symbols are placed in the Mth N-length vector of all zeros. u The N-point IDAFT is formed on consecutive entries, and the entry ranges allocated to different users u do not overlap. The N-point IDAFT is based on chirped carriers, and the phase of each chirped carrier in the chirped carriers is a bivariate polynomial of the precoded input symbol index and the time index. In addition, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index. The first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, where N≥max{M u} u∈{1,…,U} First, the wireless transmission device 102 is used to transmit M u The precoded input symbols are placed in the Mth N-length vector of all zeros. u consecutive entries to form a vector, wherein the ranges of entries assigned to different users u do not overlap. Thereafter, the wireless transmission device 102 is further configured to apply an N-point IDAFT to the vector. According to one embodiment, the method 400 further includes: after applying the N-point IDAFT to generate the signal, appending a prefix to the transmission signal. The wireless transmission device 102 ( Figure 1A ) is used to perform time domain cyclic prefix (CP) insertion at the output of the N-point IDAFT. In one implementation, the prefix is ​​a chirp period corresponding to a chirped carrier, where the frequency increases or decreases over time. Under defined conditions (i.e., if 2Nc is an integer), the chirp period prefix is ​​only a cyclic prefix.

[0089] In one implementation, if Then the wireless transmitting device 102 is used to generate a discrete affine Fourier transform extended affine frequency division multiplexing (DAFT-s-AFDM) signal or waveform in equation (1). In addition, the wireless transmitting device 102 is used to generate a signal with lower peak-to-average power ratio (PAPR) performance than the AFDM signal. In other words, the PAPR performance of the DAFT-s-AFDM signal is lower. In addition, the DAFT-s-AFDM signal is a single-carrier signal with a chirped Dirichlet pulse shape. Since the chirped pulse only affects the phase of the time domain sample but not the PAPR, the DAFT-s-AFDM signal has a PAPR performance comparable to that of DFT-s-OFDM. In other words, the PAPR performance of the DAFT-s-AFDM signal is lower than the PAPR performance of the OFDM signal and the AFDM signal. In one implementation, it is usually necessary to add Np, u≥ 1 pilot symbol and data symbol, so as to perform pilot-based channel estimation at the receiver side such as the wireless receiving device 104. In one example, M u The set of input symbols is embedded into the pilot symbol, so that The cardinality Np, u The subset of consists of pilot symbols corresponding to the transform-domain embedded pilot symbols.

[0090] At step 408, the method 400 includes: sending a signal on the wireless communication channel 106. In one implementation, the wireless communication channel 106 is first used to perform digital-to-analog conversion and up-conversion on a signal such as a DAFT-s-AFDM signal, and then serially transmit the signal to other users such as a wireless receiving device 104 on the wireless communication channel 106. According to one embodiment, the method 400 also includes: sending an indication of at least one system parameter through the signal (e.g., the DAFT-s-AFDM signal). In one implementation, the at least one system parameter may correspond to a chirp rate parameter c or an N frame size. In one example, the chirp rate corresponds to a frequency change rate of the signal, and the N frame corresponds to a frequency change rate of the signal generated by M u The N-long frame is defined by a set of input symbols. In addition, the indication of at least one system parameter is used for channel estimation and data detection at the receiver side such as the wireless receiving device 104. The method 400 achieves all the advantages and technical effects of the wireless transmitting device 102 in the wireless communication system 100A.

[0091] Steps 402 to 408 are merely illustrative, and other alternatives may be provided in which one or more steps are added, one or more steps are deleted, or one or more steps are provided in a different order without departing from the scope of the claims herein.

[0092] Figure 5A is a schematic diagram showing a wireless receiving device for receiving a signal from a wireless communication channel according to one embodiment. Figure 1A and Figure 3B The elements in describe Figure 5A . refer to Figure 5A , shows a schematic diagram 500A, including a series of operations from 502 to 530. The wireless receiving device 104 ( Figure 1A ) is used to perform the operations shown in schematic diagram 500A.

[0093] In operation, the wireless receiving device 104 is used to receive a signal from the wireless communication channel 106 ( Figure 1AThe wireless receiving device 104 is used to receive signals from U user devices, {1, ..., U} and U ≥ 1, and the user devices {1, ..., U} correspond to the wireless transmitting device 102. First, the user devices such as the wireless transmitting device 102 are used to send signals (for example, discrete affine Fourier transform spread affine radio frequency division multiplexing (DAFT-s-AFDM)) signals, and then the wireless receiving device 104 is used to receive the signals from the wireless communication channel 106. In an example, the wireless receiving device 104 can receive one or more signals from one or more user devices at the same time.

[0094] According to one embodiment, the wireless receiving device 104 is configured to receive an indication of at least one system parameter via a signal. In one implementation, the at least one system parameter may correspond to a chirp rate parameter c or an N frame size. In one example, the chirp rate corresponds to a frequency change rate of the signal, and the N frames correspond to N long frames defined by the signal. In addition, the wireless receiving device 104 uses the indication of the at least one system parameter to perform estimation and data detection of the wireless communication channel 106.

[0095] According to one embodiment, the wireless receiving device 104 is further configured to remove a chirp period prefix or a cyclic prefix (CP) from the received signal. For example, at operation 502, the wireless receiving device 104 is configured to perform time domain CP removal to remove the chirp period prefix or the cyclic prefix (CP) from the received signal. Optionally, if the signal received from a user device such as the wireless transmitting device 102 includes a transform domain (embedded) pilot symbol, the wireless receiving device 104 may use the time domain samples of the received signal corresponding to the transform domain pilot symbol for channel estimation. For example, at operation 504, the wireless receiving device 104 is configured to perform time domain channel estimation on N received symbols (i.e., the number of symbols N).

[0096] The wireless receiving device 104 is configured to apply an N-point discrete affine Fourier transform (DAFT) to the N received symbols to generate U sets, wherein each set includes M u DAFT domain symbols. For example, at operation 506, the wireless receiving device 104 is configured to apply an N-point DAFT to the N received symbols. The N-point DAFT is based on a chirped carrier, and the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of the symbol index and the time index. In one example, the vector of N DAFT domain samples includes M uThe composite contribution of U sets of transmitted symbols. In one implementation, the wireless receiving device 104 is configured to apply an N-point DAFT (i.e., an N-point (c, c) DAFT) to a vector of samples obtained by down-converting a received signal (e.g., a wireless signal), sampling the signal, and removing (i.e., discarding) a cyclic prefix from the signal. In addition, the bivariate polynomial includes a first quadratic term indexed in time and a second quadratic term indexed in symbol. In addition, the first quadratic term indexed in time and the second quadratic term indexed in symbol are associated with the same coefficient c based on the system parameter, where N ≥ max{M u}u∈{1,…,U}. In addition, the wireless receiving device 104 is used to estimate the time domain signal based on the time domain samples, and then transform the result to the DAFT domain where it needs to be equalized. For example, at operation 508, operation 510 and operation 512, the wireless receiving device 104 is used to perform equalization. Alternatively, if the DAFT domain (non-embedded) pilot symbols are received by the wireless receiving device 104, the channel estimation can be performed directly in the DAFT domain estimation (or DAFT domain pilot estimation). For example, at operation 514, at operation 516 and at operation 518, the wireless receiving device 104 is used to perform DAFT domain estimation based on the received DAFT domain pilot samples.

[0097] According to one embodiment, the signal generated by the wireless receiving device 104 at the output of the N-point DAFT includes u The transmitted precoded symbols and R u The M related to the pilot symbol received in the DAFT domain u DAFT domain received samples. The indices of these DAFT domain received samples define the set The set is a subset of {0, ..., N-1}. In one implementation, if the set of DAFT domain pilot symbol indices is empty, then based on the pilot symbol corresponding to the embedded data symbol (for example, M u DAFT domain transmission symbol) to estimate the wireless communication channel 106 of the user equipment (ie, user equipment u). In another implementation, if the set If not empty, then the set is based on the N frames generated by the N-point DAFT. The wireless communication channel 106 is estimated by using the DAFT domain samples received at the index defined by the wireless receiving device 104. In addition, the wireless receiving device 104 is further configured to use the channel estimate obtained thereby to equalize the corresponding M u A collection of DAFT domain receive symbols.

[0098] The wireless receiving device 104 is further configured to apply an inverse precoder to each of the U sets of DAFT-domain precoded symbols to generate U sets of estimated input symbols.u Point Discrete Affine Inverse Fourier Transform (IDAFT). For example, at operations 520, 522, and 524, the wireless receiving device 104 is configured to apply M to each of the U sets including DAFT domain symbols. u Point IDAFT (i.e. M u point (c, c)IDAFT) to generate a set of estimated input symbols based on a bivariate polynomial of the DAFT domain symbol index and the time index. In addition, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index. In addition, the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c. In addition, the wireless receiving device 104 is used to: equalize the wireless communication channel 106 affecting the remaining samples by using a linear minimum mean squared error (LMMSE) equalization, etc. (for example, at operations 526, 528, and 530), and by applying M to the output of the above equalization step with the same coefficient c u The point (c, c) IDAFT is used to estimate the received data symbol of the user equipment (eg, u).

[0099] The wireless receiving device 104 is used to receive a signal, for example, a discrete affine Fourier transform spread affine frequency division multiplexing (DAFT-s-AFDM) signal, which is a single carrier signal with a chirped Dirichlet pulse shape. Advantageously, compared with conventional methods, the DAFT-s-AFDM signal and the chirped period prefix (i.e., chirped pilot) are orthogonal in the DAFT domain, which provides improved PAPR performance. Therefore, when the wireless receiving device 104 applies the DAFT transform, the DAFT-s-AFDM signal can be separated from the data.

[0100] Figure 5B is a schematic diagram showing a wireless receiving device for receiving a signal from a wireless communication channel according to another embodiment. Figure 1A and Figure 5A The elements in describe Figure 5B . refer to Figure 5B , shows a schematic diagram 500B, including a series of operations from 502 to 532 to 556. The wireless receiving device 104 ( Figure 1A ) is used to perform the operations shown in the schematic diagram 500B without explicitly using the DAFT / IDAFT module.

[0101] First, the wireless receiving device 104 is used to receive a signal from the wireless communication channel 106. In one example, since there is no DAFT module, the wireless receiving device 104 cannot directly access the DAFT domain. Thereafter, at operation 524, the wireless receiving device 104 is used to perform γ on the output of the time domain CP removal module. n chirp, and then subtract samples corresponding to the data-only portion of the received signal from the output of the time-domain CP removal module. Thereafter, the wireless receiving device 104 is configured to perform operation 536 corresponding to a DFT-s-OFDM receiver, which also includes a series of operations. For example, at operation 538, the wireless receiving device 104 is configured to perform an N-point FFT module to subtract the frequency domain samples {r m} m＝0 … N-1 The wireless receiving device 104 is further configured to perform frequency domain equalization, for example, at operations 540, 542, and 544. Thereafter, at operations 546, 548, and 550, the wireless receiving device 104 is configured to perform frequency domain equalization on the received signal. u Finally, data symbol estimation is performed, as shown in operations 552, 554, and 556. In one example, by applying M to the output of the above-mentioned equalization operations (e.g., operations 540, 542, and 544), u Point IFFT is used to perform data symbol estimation.

[0102] In one implementation, if the DAFT domain (i.e., non-embedded) pilot symbol is sent by user u (i.e., in is not empty), the wireless receiving device 104 is used to estimate the DAFT domain channel response. When there is no DAFT module, this is done, for example, based on time domain samples, which are obtained by subtracting time domain samples corresponding to the data-only portion of the received signal from the output of the CP removal module. For example, at operation 502, the wireless receiving device 104 is used to perform time domain CP removal on the received signal, for example, by using the time domain CP removal module. Optionally, at operation 532, the wireless receiving device 104 can be used to perform channel estimation based on the time domain pilot samples, as shown in the following equation (5).

[0103]

[0104] Figure 6 FIG. 1 is a flow chart illustrating a method for receiving a signal on a wireless communication channel according to one embodiment. Figures 1A to 5B The elements in describe Figure 6 . refer to Figure 6, showing a method for transmitting data from the wireless communication channel 106 ( Figure 1A Flow chart of a method 600 for receiving a signal in the wireless receiving device 104 ( Figure 1A ) is used to execute method 600.

[0105] The method 600 is for receiving a signal on a wireless communication channel 106. The signal corresponds to a discrete affine Fourier transform (DAFT) spread AFDM signal with low peak-to-average power ratio (PAPR) performance for wireless transmission with an improved AFDM waveform for dual dispersion channels.

[0106] At step 602, method 600 includes: receiving a signal, wherein the signal includes M from U users u The wireless receiving device 104 is configured to receive signals from U user devices such as the wireless transmitting device 102. According to one embodiment, the method 600 further includes: receiving an indication of at least one system parameter through a signal. In one implementation, the at least one system parameter may correspond to a chirp rate or an N frame size. According to one embodiment, the method 600 further includes: removing a chirp period prefix or a cyclic prefix (CP) from the received signal to generate a frame including M u The wireless receiving device 104 is configured to perform time domain CP removal to remove the chirp period prefix or cyclic prefix (CP) from the received signal.

[0107] At step 604, method 600 includes applying an N-point discrete affine Fourier transform (DAFT) to the N received samples after removing the prefix to generate a matrix containing M u The vector of N DAFT domain samples of the composite contribution of U sets of transmitted symbols. The N-point DAFT is based on a bivariate polynomial of symbol index and time index, which includes a first quadratic term for the time index and a second quadratic term for the symbol index. In addition, the first quadratic term for the time index and the second quadratic term for the symbol index are associated with the same coefficient c based on system parameters and channel parameters. In one example, the number of received symbols N is greater than M u In addition, the wireless receiving device 104 is used to estimate the time domain signal based on the time domain samples, and then transform the result into the DAFT domain for equalization.

[0108] According to one embodiment, the method 600 further includes: u At least one of the U sets of DAFT domain symbols and also includes Np, u The method 600 also includes: equalizing the corresponding M based on the chirped carrier.u DAFT domain symbols, the phase of each chirp carrier in the chirp carrier is Np before applying the inverse precoder, u The wireless receiving device 104 is used to: before applying the inverse precoder, based on using R u The channel estimation equalization corresponding to the M u DAFT domains receive symbols. In this embodiment, for M u At least one set of received symbols, the signal includes R u A set of DAFT domain pilot symbols.

[0109] At step 606, the method 600 includes applying an inverse precoder to each of the sets of DAFT domain symbols to generate U sets of estimated symbols, wherein the inverse precoder includes M of the chirped carrier. u The phase of each chirp carrier in the chirp carrier is a bivariate polynomial of the DAFT domain symbol index and the time index. The wireless receiving device 104 is configured to apply M to each set of the set including the DAFT domain symbols based on the bivariate polynomial of the DAFT domain symbol index and the time index. u Point IDAFT (i.e. M u point (c, c)IDAFT) to generate a set of estimated input symbols. In addition, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index, and the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c. In addition, the wireless receiving device 104 is used to: first equalize the wireless communication channel 106 affecting the remaining samples, and apply M to the output of the above equalization step with the same coefficient c u The method 600 achieves all the advantages and technical effects of the wireless receiving device 104 in the wireless communication system 100A.

[0110] Steps 602 to 606 are merely illustrative, and other alternatives may be provided in which one or more steps are added, one or more steps are deleted, or one or more steps are provided in a different order without departing from the scope of the claims herein.

[0111] A computer program product is provided, comprising program instructions, which, when executed by one or more processors in a computer system, are used to perform method 400 and / or method 600. The computer program product is implemented as an algorithm, embedded in software, which is stored in a non-transitory computer-readable storage medium having program instructions stored thereon, which can be executed by one or more processors in a computer system to perform method 400 and / or method 600. The non-transitory computer-readable storage medium may include, but is not limited to: an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above devices. Examples of implementations of computer-readable storage media include, but are not limited to: an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a flash memory, a secure digital (SD) card, a solid-state drive (SSD), a computer-readable storage medium, and / or a CPU cache memory.

[0112] A computer system is also provided, comprising one or more processors and one or more memories, the one or more memories storing program instructions, which when executed by the one or more processors, cause the one or more processors to perform method 400 and / or method 600. The computer system is implemented as an algorithm, embedded in software, which is stored in a non-transitory computer-readable storage medium having program instructions stored thereon, which can be executed by one or more processors in the computer system to perform method 400 and / or method 600. The non-transitory computer-readable storage medium may include, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above devices. Examples of implementations of computer-readable storage media include, but are not limited to, electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), read-only memory (ROM), hard disk drive (HDD), flash memory, secure digital (SD) card, solid-state drive (SSD), computer-readable storage medium, and / or CPU cache memory.

[0113] Without departing from the scope of the invention as defined by the appended claims, the embodiments of the invention described above may be modified. "Including", "incorporating", "having", "being / being" and the like used to describe and claim the present invention are intended to be interpreted in a non-exclusive manner, i.e., items, components or elements not explicitly described may also exist. References to the singular should also be interpreted as involving the plural. The word "exemplary" used herein means "as an example, instance or illustration". Any embodiment described as "exemplary" is not necessarily interpreted as being more preferred or more advantageous than other embodiments, and / or excluding the combination of the features of other embodiments. The word "optionally" used herein means "provided in some embodiments and not provided in other embodiments". It should be understood that certain features of the present invention described in the context of a single embodiment for clarity may also be provided in a single embodiment by combination. On the contrary, the various features of the present invention described in the context of a single embodiment for brevity may also be provided individually or in any suitable combination or as any other described embodiment of the present invention.

Claims

1. A wireless transmission device (102) for transmitting a signal on a wireless communication channel (106), wherein the wireless transmission device (102) is further configured to: Get M from user u u A set of input symbols, where u∈{1,…,U} and U≥1; For the M u A precoder is applied to a set of input symbols to generate a set of precoded input symbols, wherein the precoder includes a chirped carrier-based M u A point discrete affine Fourier transform DAFT, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of an input symbol index m and a time index n, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index, and the first quadratic term of the time index and the second quadratic term of the input symbol index are associated with a same coefficient c based on a system parameter; Apply an N-point discrete affine inverse Fourier transform IDAFT to a vector, where the vector is obtained by dividing the M u The precoded input symbols are placed in the Mth N-length vector of all zeros. u The N-point IDAFT is formed on consecutive entries, the entry ranges allocated to different users u do not overlap, the N-point IDAFT is based on a chirped carrier, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a precoded input symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, wherein N≥max{M u } u∈{1,…,U} ; The signal is transmitted over the wireless communication channel (106).

2. The device (102) according to claim 1, further configured to send an indication of at least one system parameter via the signal.

3. The apparatus (102) according to claim 1 or 2, further configured to form the M by embedding transform domain pilot symbols into non-pilot input symbols. u A set of input symbols.

4. The apparatus (102) of claim 3, further configured to form the M by inserting guard samples between different embedded pilot symbols and between embedded pilot symbols and non-pilot input symbols. u A set of input symbols.

5. The device (102) according to claim 4, characterized in that The guard samples have non-zero values.

6. The device (102) according to claim 1 or 2, further configured to: u pilot symbols are placed at the input of the N-point IDAFT. u consecutive entries, append R to the transmission signal u A set of DAFT domain pilot symbols, where The R u consecutive entries with the M u The entries occupied by the outputs of the point DAFT do not overlap.

7. The device (102) according to claim 6, further configured to: insert guard samples between predefined symbols to form the R u A set of additional DAFT-domain pilot symbols and inserting guard samples in the vector at the input of the N-point IDAFT, wherein The input of the N-point IDAFT is located at the M u The set of precoded input symbols and the R u between sets of additional DAFT-domain pilot symbols.

8. The apparatus (102) according to any one of claims 1 to 7, further configured to: append a chirp period prefix or a cyclic prefix to the transmit signal after applying the N-point IDAFT to generate the signal.

9. A method (400) for transmitting a signal on a wireless communication channel, the method (400) comprising: Get M from user u u The set of input symbols, where u∈{1,…,U} and U≥1; For the M u Applying a precoder to each input symbol in a set of input symbols to generate a set of precoded input symbols, wherein the precoder includes an M based on a chirped carrier. u A point discrete affine Fourier transform DAFT, wherein the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of an input symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the input symbol index, and the first quadratic term of the time index and the second quadratic term of the time index are associated with the same coefficient c based on a system parameter and a channel parameter; Applying an N-point discrete affine inverse Fourier transform IDAFT to a vector to generate the signal, wherein the vector is obtained by dividing the M u The preceding input symbols are placed in the Mth of the all-zero N-length vectors u The N-point IDAFT is formed on consecutive entries, the entry ranges allocated to different users u do not overlap, the N-point IDAFT is based on a chirped carrier, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a precoded input symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the precoded input symbol index, the first quadratic term of the time index and the second quadratic term of the precoded input symbol index are associated with the same coefficient c, wherein N≥max{M u } u∈{1,…,U} ; The signal is transmitted over the wireless communication channel.

10. The method (400) of claim 9, further comprising sending an indication of at least one system parameter via the signal.

11. The method (400) according to claim 9 or 10, further comprising: In order to obtain M u at least one set of input symbols, receiving input symbols from a user equipment, and embedding transform domain pilot symbols into the received input symbols to form the corresponding M u A set of input symbols.

12. The method (400) of claim 11, further comprising inserting a guard sample between two symbols into the corresponding M u The set of input symbols.

13. The method (400) according to claim 12, characterized in that: The guard samples include non-zero values.

14. The method (400) according to claim 9 or 10, further comprising: By placing the R u pilot symbols are placed at the input of the N-point IDAFT. u consecutive entries, append R to the transmission signal u A set of DAFT domain pilot symbols, where the R u consecutive entries with the M u The entries occupied by the outputs of the point DAFT do not overlap.

15. The method (400) of claim 14, further comprising: Guard samples are inserted between predefined symbols to form the R u A set of additional DAFT domain pilot symbols and inserting guard samples in the vector at the input of the N-point IDAFT, wherein the input of the N-point IDAFT is located at the M u The set of precoded input symbols and the R u between sets of additional DAFT-domain pilot symbols.

16. The method (400) according to any one of claims 9 to 15, further comprising: After applying the N-point IDAFT to generate the signal, a cyclic prefix is ​​appended to the transmit signal.

17. A wireless receiving device (104) for receiving a signal from a wireless communication channel (106), the wireless receiving device (104) being configured to: receiving the signal, wherein The signal comes from U user equipments, {1, ..., U} and U ≥ 1, and each user equipment {1, ..., U} is a device according to any one of claims 1 to 8; Apply an N-point discrete affine Fourier transform DAFT to the N received symbols to generate U sets, where each set includes M u DAFT domain symbols, the N-point DAFT is based on a chirped carrier, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the symbol index, the first quadratic term of the time index and the second quadratic term of the symbol index are associated with the same coefficient c based on a system parameter, wherein N≥max{M u } u∈{1,…,U} ; Applying an inverse precoder to each of the sets of DAFT domain symbols to generate U sets of estimated input symbols, wherein the inverse precoder includes an M chirp carrier-based u A point discrete affine inverse Fourier transform IDAFT, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a DAFT domain symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index, the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c.

18. The apparatus (104) of claim 17, further configured to receive an indication of at least one system parameter via the signal.

19. The device (104) according to claim 17 or 18, characterized in that The included u At least one of the U sets of input symbols also includes R u The device is also used to: before applying the inverse precoder, use the R u The corresponding M u DAFT domain receives symbols.

20. The device (104) according to claim 17 or 18, characterized in that For M u at least one set of received symbols, the signal at the output of the N-point DAFT comprises R u A set of DAFT domain pilot symbols; the device is also used to: before applying the inverse precoder, use the R u The corresponding M DAFT-domain pilot symbols are equalized u A collection of DAFT domain receive symbols.

21. The apparatus (104) according to any one of claims 17 to 20, further configured to: apply the N-point DAFT to generate the M-point DAFT u Before transmitting U sets of DAFT domain symbols, a chirp period prefix or a cyclic prefix is ​​removed from the received signal.

22. A method (600) for receiving a signal from a wireless communication channel (106), the method (600) comprising: Receive the signal, wherein the signal includes an M for the user u U sets of received symbols, where u∈{1,…,U} and U≥1; For the M u The aggregation of U sets of received symbols applies an N-point discrete affine Fourier transform DAFT to generate U sets, where each set includes M u DAFT domain symbols, the N-point DAFT is based on a chirped carrier, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the symbol index, the first quadratic term of the time index and the second quadratic term of the symbol index are associated with the same coefficient c based on a system parameter and a channel parameter, wherein N≥max{M u } u∈{1,…,U} ; Applying an inverse precoder to each of the sets of DAFT domain symbols to generate U sets of estimated symbols, wherein the inverse precoder includes an M based on a chirped carrier. u A point discrete affine inverse Fourier transform IDAFT, the phase of each chirped carrier in the chirped carrier is a bivariate polynomial of a DAFT domain symbol index and a time index, the bivariate polynomial includes a first quadratic term of the time index and a second quadratic term of the DAFT domain symbol index, the first quadratic term of the time index and the second quadratic term of the DAFT domain symbol index are associated with the same coefficient c.

23. The method (600) of claim 22, characterized in that: Also included is receiving, via the signal, an indication of at least one of the system parameter and the channel parameter.

24. The method (600) according to claim 22 or 23, characterized in that The included u At least one of the U sets of DAFT domain symbols also includes R u transform domain pilot symbols; the method (600) further comprises: before applying the inverse precoder, using the R u The corresponding M u DAFT domain symbol.

25. The method (600) according to claim 22 or 23, characterized in that For M u at least one set of received symbols, the signal comprising R u A set of DAFT domain pilot symbols; The method (600) further comprises: before applying the inverse precoder, using the R u The corresponding M DAFT-domain pilot symbols are equalized u A collection of DAFT domain symbols.

26. The method (600) according to any one of claims 22 to 25, further comprising: In applying the N-point DAFT to generate the M u Before transmitting U sets of DAFT domain symbols, a chirp period prefix or a cyclic prefix is ​​removed from the received signal.

27. A computer program product comprising program instructions which, when executed by one or more processors in a computer system, perform the method (400) according to any one of claims 9 to 16 and / or the method (600) according to any one of claims 22 to 26.

28. A computer system comprising one or more processors and one or more memories, wherein the one or more memories store program instructions, and when the program instructions are executed by the one or more processors, the one or more processors perform the method (400) according to any one of claims 9 to 16 and / or the method (600) according to any one of claims 22 to 26.

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