Communication system and communication method using pre-channel equalization

Abstract

A communication system and a communication method using pre-channel equalization are disclosed. The disclosed communication method according to one embodiment is performed in a computing device including one or more processors and a memory for storing one or more programs to be executed by the one or more processors, and is a communication method for signal transmission of a transmitter in a communication system using pre-channel equalization, the method comprising the steps of: generating a zero padding section or a cyclic prefix (CP) section in the foremost section of a data frame of any one of a delay-Doppler domain, a frequency-time domain and a delay-time domain; and generating a transmission signal by performing pre-equalization on a signal of any one of the delay-Doppler domain, the frequency-time domain and the delay-time domain.

Description

Communication system and method using pre-channel equalization

[0001] An embodiment of the present invention relates to a communication technology using pre-channel equalization.

[0002] Recently, the speed of mobile devices equipped with wireless communication technology, such as autonomous vehicles and drones, is increasing. Consequently, demand for Orthogonal Time Frequency Space (OTFS), which demonstrates high performance in high-speed mobile device communication, is increasing. OTFS is used in both single-user and multi-user scenarios, and can be categorized into uplink and downlink structures depending on whether the sender is a user or a base station.

[0003] Figure 1 is a diagram showing the process of transmitting and receiving signals between a transmitter and a receiver in different domains in a typical OTFS (Orthogonal Time Frequency Space).

[0004] Referring to FIG. 1, an original data signal is generated from a transmitter, and the original data signal is mapped to a delay-Doppler domain of size M×N, and then converted to a frequency-time domain by an Inverse Symplectic Fast Fourier Transform (ISFFT). That is, a signal in the delay-Doppler domain can be converted to a frequency-time domain by spreading it two-dimensionally through an ISFFT operation. Then, a transmission signal in the delay-time domain can be generated by converting the data signal in the frequency-time domain by an Inverse Fast Fourier Transform (IFFT), and transmitted to a receiver. At this time, the transmission signal passes through a wireless channel and is received by the receiver.

[0005] Then, the receiver converts the received signal in the delay-time domain into the frequency-time domain by performing an FFT (Fast Fourier Transform) and then converts the signal in the frequency-time domain into an SFFT (Symplectic Fast Fourier Transform) to generate an original data estimation signal in the delay-Doppler domain.

[0006] When transmitting a signal from a transmitter to a receiver, delay spreading occurs due to multipath effects in the wireless channel. To prevent inter-symbol interference, zero padding is placed at the end of the data frame. In Figure 1, the zero padding section is denoted by z.

[0007] Meanwhile, in the case of a multi-user uplink OTFS system, delay-time domain signals transmitted by different users are received by a single receiver while invading each other's areas in the delay-Doppler domain through different wireless channels. This will be described with reference to FIGS. 2 to 4 as follows. FIGS. 2 to 4 are diagrams showing a state in which interference occurs between users in a multi-user environment of an OTFS system.

[0008] First, in Figure 2, four users have data (X) in non-overlapping locations. Dd,1 ~ X Dd,4 ) can be seen. Here, for the convenience of explanation, the signals of four users are displayed separately, but in reality, a single signal is received that combines the signals of four users.

[0009] Next, Fig. 3 shows the state in which the signals of four users are received by the receiver through each channel, and each user's signal (R dD,1 ~ R dD,4) as they pass through different channels, we can see that they experience channel distortion in different forms and invade each other's domain.

[0010] Here, as shown in Fig. 4, when the channel of User 1 is compensated, the channel of User 1 is compensated, but the channels of the remaining users, that is, User 2, User 3, and User 4, are not compensated according to their own channels, but are compensated according to the channel of User 1, so that the signal can be seen to spread further into the areas of other users. In this way, in the OTFS system of a multi-user environment, there is a problem that interference between users increases and BER (Bit Error Rate) performance deteriorates.

[0011] An embodiment of the present invention provides a communication system and method using pre-channel equalization capable of reducing interference between users.

[0012] An embodiment of the present invention provides a communication system and a communication method using pre-channel equalization that can reduce the amount of computation of a receiver.

[0013] A communication method according to one embodiment disclosed is a method performed in a computing device having one or more processors and a memory storing one or more programs executed by the one or more processors, and is a communication method for transmitting a signal by a transmitter in a communication system using pre-channel equalization, the method comprising: generating a zero padding section or a CP (Cyclic Prefix) section at the front section of a data frame in any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain; and generating a transmission signal by performing pre-equalization on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

[0014] The above pre-equalization may be performed in advance to compensate in a direction opposite to the spreading of data that will occur in the channel between the transmitter and the receiver before transmitting a signal from the transmitter to the receiver.

[0015] The step of generating the transmission signal may include: obtaining channel information between the transmitter and a receiver that will receive the transmission signal; generating an equalization matrix based on the channel information; and generating the transmission signal by multiplying the equalization matrix by a signal in any one of the delay-Doppler domain, frequency-time domain, and delay-time domain by a column.

[0016] The above equalization matrix (H pre ) can be generated by the following mathematical expression 1 or mathematical expression 2.

[0017] (Equation 1)

[0018]

[0019] (Equation 2)

[0020]

[0021] : Channel matrix for the nth column of the signal matrix in the delay-time domain

[0022] : Hermitian matrix of

[0023] : The variance of the noise of the corresponding channel

[0024] : Identity matrix corresponding to the length M of the nth column of the signal matrix in the delay-time domain

[0025] The step of generating the above transmission signal is to multiply the equalization matrix column by column by the following mathematical expression 3 or mathematical expression 4 to generate the transmission signal ( ) and can generate a matrix of transmission signals by concatenating each column of the transmission signal.

[0026] (Equation 3)

[0027]

[0028] (Equation 4)

[0029]

[0030] : The nth column of the signal matrix in the delay-time domain

[0031] The above communication system is an OTFS (Orthogonal Time Frequency Space) communication system, and the communication method may further include, before the step of generating the zero padding section or CP section, the step of receiving data bits, digitally modulating them, and mapping the modulated data symbols to a delay-Doppler domain; the step of converting a signal in the delay-Doppler domain into a frequency-time domain by performing an ISFFT (Inverse Symplectic Fast Fourier Transform); and the step of generating a signal in the delay-time domain by performing an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain.

[0032] The above communication system is an OFDM (Orthogonal Frequency Division Multiplexing) communication system, and the communication method may further include, before the step of generating the zero padding section or CP section, the step of receiving data bits, digitally modulating them, and mapping the modulated data symbols to a frequency-time domain; and the step of generating a signal in a delay-time domain by performing an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain.

[0033] A communication method according to another embodiment disclosed is a method performed in a computing device having one or more processors and a memory storing one or more programs executed by the one or more processors, and a communication method for receiving a signal by a receiver in a communication system using pre-channel equalization, the method comprising the steps of: generating a zero padding section or a CP (Cyclic Prefix) section at the front section of a data frame from a transmitter in any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain, and receiving a transmission signal in which pre-equalization is performed on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

[0034] A communication system according to one embodiment disclosed is a communication system using pre-channel equalization, including a transmitter and a receiver, wherein the transmitter includes a channel equalization unit that generates a zero padding section or a CP (Cyclic Prefix) section at the front end of a data frame in any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain, and performs pre-equalization on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain to generate a transmission signal.

[0035] According to another embodiment of the disclosure, a communication system includes a transmitter and a receiver, and is a communication system using pre-channel equalization, wherein the receiver receives a transmission signal in which a zero padding section or a CP (Cyclic Prefix) section is generated at the front end of a data frame of any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain from the transmitter, and in which pre-equalization is performed on a signal of any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

[0036] A communication method according to another embodiment disclosed is a method performed in a computing device having one or more processors and a memory storing one or more programs executed by the one or more processors, the method comprising the steps of: obtaining channel information between the transmitter and the receiver; generating an equalization matrix based on the channel information; and generating a transmission signal by multiplying a signal in any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain by the equalization matrix column by column.

[0037] A communication method according to another embodiment disclosed is a method performed in a computing device having one or more processors and a memory storing one or more programs executed by the one or more processors, the method comprising: a communication method using pre-channel equalization of each transmitter, which is a user terminal, in a communication system of an uplink multi-user scenario, the method comprising: obtaining channel information between the transmitter and the receiver; generating an equalization matrix based on the channel information; and generating a transmission signal by multiplying a signal in any one of a delay-Doppler domain, a frequency-time domain, and a delay-time domain by the equalization matrix column by column.

[0038] According to the disclosed embodiment, since the transmitter transmits data signals after pre-channel equalization, the receiver receives signals from users without interference, thereby reducing interference between users in a multi-user communication system. Furthermore, since the receiver receives signals that have been pre-channel equalized, separate channel equalization is not required, thereby reducing the computational load of the receiver.

[0039] Figure 1 is a diagram showing the process of transmitting and receiving signals between a transmitter and a receiver in a general OTFS (Orthogonal Time Frequency Space) at the domain level.

[0040] Figures 2 to 4 are drawings showing a state in which interference occurs between users in a multi-user environment of an OTFS system.

[0041] FIG. 5 is a diagram comparing the channel compensation of a conventional OTFS communication system and the channel compensation of an OTFS communication system according to an embodiment of the present invention.

[0042] FIG. 6 is a diagram comparing user interference of a conventional OTFS communication system and user interference of an OTFS communication system according to an embodiment of the present invention.

[0043] FIG. 7 is a drawing comparing the location of the zero padding section of the existing OTFS communication system with the location of the zero padding section of the OTFS communication system according to the embodiment of the present invention.

[0044] FIG. 8 is a diagram illustrating an OTFS communication system according to one embodiment of the present invention.

[0045] FIG. 9 is a diagram schematically illustrating a data signal processing process in a transmitter of an OTFS communication system according to one embodiment of the present invention.

[0046] Figure 10 is a graph comparing the BER (Bit Error Rate) performance of a multi-user environment of an existing OTFS communication system and the OTFS communication system of the present invention.

[0047] Figure 11 is a graph comparing the PAPR (Peak to Average Power Ratio) performance of the existing OTFS communication system and the OTFS communication system of the present invention.

[0048] Figure 12 is a flowchart showing a communication method of a communication system according to one embodiment of the present invention.

[0049] FIG. 13 is a block diagram illustrating a computing environment including a computing device suitable for use in exemplary embodiments.

[0050] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, devices, and / or systems described herein. However, these are merely examples and the present invention is not limited thereto.

[0051] In describing embodiments of the present invention, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and this may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing embodiments of the present invention and should not be limited in any way. Unless clearly used otherwise, the singular form includes the plural form. In this description, expressions such as "comprises" or "having" are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, parts or combinations thereof other than those described.

[0052] In the following description, the terms "transmission," "communication," "sending," "receiving," and other similar terms for signals or information include not only the direct transmission of signals or information from one component to another, but also transmission via another component. In particular, "transmitting" or "sending" a signal or information to one component indicates the final destination of the signal or information, and does not mean the direct destination. The same applies to "receiving" a signal or information. In addition, in this specification, the "relationship" of two or more pieces of data or information means that when one piece of data (or information) is acquired, at least a portion of the other piece of data (or information) can be acquired based on it.

[0053] Meanwhile, directional terms such as upper, lower, one side, and the other side are used in reference to the orientation of the disclosed drawings. Since components of embodiments of the present invention can be positioned in various orientations, directional terms are used for illustrative purposes and are not intended to be limiting.

[0054] Additionally, while terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms may be used to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component."

[0055] In the disclosed embodiment, in a communication system using OTFS (Orthogonal Time Frequency Space), when a transmitter transmits a data signal to a receiver, distortion due to the influence of the channel can be compensated for in advance (i.e., pre-equalization) before transmission. That is, FIG. 5 is a diagram comparing the channel compensation of a conventional OTFS communication system with the channel compensation of an OTFS communication system according to an embodiment of the present invention.

[0056] Looking at Figure 5 (a), when a data signal is sent from a transmitter, the data spreads due to the Doppler effect in the wireless channel, resulting in the signal being received by the receiver in a distorted state. Then, the receiver compensates for the distortion in the opposite direction through channel equalization.

[0057] On the other hand, looking at (b) of FIG. 5, in the disclosed embodiment, before sending a data signal from the transmitter, compensation is performed in advance through channel equalization (i.e., compensation is performed in advance in the opposite direction to the data spreading that will occur in the wireless channel) and then transmitted. Then, data spreading occurs in the direction opposite to the channel equalization in the wireless channel, so that the receiver receives a signal without channel distortion. In this case, the receiver does not need to perform separate compensation for channel distortion (i.e., channel equalization), so that the amount of computation can be reduced.

[0058] In one embodiment, when the transmitter is a user terminal and the receiver is a base station, if each user terminal compensates for channel distortion through channel equalization before transmitting a signal, the base station receives a signal without channel distortion and does not need separate channel equalization, thereby reducing the computational burden. This reduction in computational burden is particularly effective in multi-user cases. However, this is not limited to this and can of course be applied even when the transmitter is a base station and the receiver is a user terminal.

[0059] Figure 6 is a diagram comparing the user interference of a conventional OTFS communication system with the user interference of an OTFS communication system according to an embodiment of the present invention. For convenience of explanation, the signals of four users are displayed separately. However, in reality, a single signal is received, combining the signals of all four users.

[0060] Looking at (a) of Fig. 6, in the existing OTFS communication system, each user's signal experiences channel distortion and invades each other's area, and when the channel of user 1 is compensated, the remaining users are compensated according to the channel of user 1, so the signal spreads further into the areas of other users, which increases interference between users.

[0061] On the other hand, looking at (b) of FIG. 6, it can be seen that in the disclosed embodiment, since the transmitter transmits the data signal after performing channel equalization in advance, the signals of the users are received by the receiver without interfering with each other (i.e., without invading each other's areas), eliminating the need for separate channel equalization. In other words, according to the disclosed embodiment, interference between users can be reduced in a communication system used by multiple users.

[0062] Meanwhile, in the disclosed embodiment, since channel equalization is performed in advance at the transmitter, a zero padding section can be created at the very beginning of the data frame. Fig. 7 is a diagram comparing the location of the zero padding section of a conventional OTFS communication system with the location of the zero padding section of an OTFS communication system according to an embodiment of the present invention.

[0063] Looking at (a) of Fig. 7, in the existing OTFS communication system, data diffusion due to the Doppler effect occurs in the direction of time flow in the wireless channel, so a zero padding section was created in the last section of the data frame to prevent data loss.

[0064] On the other hand, looking at (b) of FIG. 7, the OTFS communication system according to the disclosed embodiment performs channel equalization by inversely compensating for data spread in the wireless channel in advance (i.e., in the reverse direction of time) at the transmitter, so that data loss can be prevented by creating a zero padding section at the front section of the data frame.

[0065] Meanwhile, while the zero-padding section is described here as being created at the very beginning of the data frame, this is not limited to this, and a CP (Cyclic Prefix) section can also be created at the very beginning of the data frame. In other words, a zero-padding section or CP section can be created at the very beginning of the data frame.

[0066] FIG. 8 is a diagram illustrating an OTFS communication system according to one embodiment of the present invention, and FIG. 9 is a diagram schematically illustrating a data signal processing process in a transmitter of the OTFS communication system according to one embodiment of the present invention. Referring to FIGS. 8 and 9, the OTFS communication system (100) may include a transmitter (102) and a receiver (104).

[0067] The transmitter (102) may include a symbol mapping unit (111), an OTFS modulation unit (113), and a channel equalization unit (115). The symbol mapping unit (111) may receive data bits, digitally modulate them, and then map the modulated data symbols to a delay-Doppler domain (dD domain).

[0068] That is, the symbol mapping unit (111) can map each modulated data symbol to a data frame of the delay-Doppler domain. At this time, the data frame can be formed of a grid of size M×N. M may be the number of grids in the delay axis, and N may be the number of grids in the Doppler axis.

[0069] The OTFS modulation unit (113) can convert a signal in the delay-Doppler domain into a frequency-time domain (FT domain) by performing an ISFFT (Inverse Symplectic Fast Fourier Transform) and can generate a signal in the delay-time domain (dT domain) by performing an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain.

[0070] The channel equalizer (115) may play a role in compensating for the influence of the channel in advance in the transmitter (102). The channel equalizer (115) may generate a zero padding section in the data frame of the delay-time domain. At this time, the zero padding section is generated at the very beginning of the data frame of the delay-time domain. That is, in the disclosed embodiment, since the transmitter (102) performs channel equalization by inversely compensating for data diffusion in the wireless channel in advance, data loss can be prevented by generating a zero padding section at the very beginning of the data frame. According to the disclosed embodiment, the zero padding section is not generated until a signal of the delay-time domain is generated.

[0071] Additionally, the channel equalizer (115) may generate an equalization matrix based on channel information between the transmitter (102) and the receiver (104). In one embodiment, the channel equalizer (115) may obtain channel information using a signal received from the receiver (104), but is not limited thereto, and the transmitter (102) may transmit a signal to the receiver (104) and receive feedback from the receiver (104) on channel information estimated by the receiver (104).

[0072] In one embodiment, the channel equalizer (115) may generate an equalization matrix according to channel information between the transmitter (102) and the receiver (104) using the Minimum Mean Square Error (MMSE) equalization technique. In this case, the channel equalizer (115) may generate an equalization matrix (H) using the following mathematical expression 1. pre ) can be created.

[0073] (Equation 1)

[0074]

[0075] : Channel matrix for the nth column of the signal matrix in the delay-time domain

[0076] : Hermitian matrix of

[0077] : The variance of the noise of the corresponding channel

[0078] : Identity matrix corresponding to the length M of the nth column of the signal matrix in the delay-time domain

[0079] Here, the use of the MMSE (Minimum Mean Square Error) equalization technique is described as an example, but it is not limited to this, and it is of course possible to use various other equalization techniques, such as the Zero-Forcing technique. For example, the channel equalization unit (115) can be expressed as an equalization matrix (H) using the following mathematical expression 2. pre ) can also be created.

[0080] (Equation 2)

[0081]

[0082] The channel equalizer (115) applies an equalization matrix (H) to the signal in the delay-time domain in which a zero padding section is created in the first section of the data frame. pre) can be multiplied by column to generate a transmission signal to be transmitted to the receiver (104). The equalization matrix (H) of mathematical expression 1 pre ), the channel equalizer (115) transmits the signal ( ) can be generated. The channel equalizer (115) can generate a matrix of a transmission signal by connecting each column calculated by mathematical expression 3. Similarly, the equalization matrix (H) of mathematical expression 2 pre ) can also be used to generate a corresponding transmission signal.

[0083] (Equation 3)

[0084]

[0085] : The nth column of the signal matrix in the delay-time domain

[0086] The receiver (104) can receive a transmission signal transmitted from the transmitter (102) through a channel. The receiver (104) can convert a reception signal in a delay-time domain into a frequency-time domain by performing an FFT (Fast Fourier Transform) transformation, and can generate an original data estimation signal in a delay-Doppler domain by performing an SFFT (Symplectic Fast Fourier Transform) transformation on the signal in the frequency-time domain.

[0087] Meanwhile, although it has been described here that the transmitter (102) of the OTFS communication system transmits a signal by compensating for the influence of the channel in advance, it is not limited thereto, and this can also be applied to the transmitter of OFDM (Orthogonal Frequency Division Multiplexing) to transmit a signal after compensating for the influence of the channel in advance.

[0088] In this case, the OFDM transmitter can receive data bits, digitally modulate them, and then map the modulated data symbols to the frequency-time domain. Next, the signal in the frequency-time domain can be converted using an Inverse Fast Fourier Transform (IFFT) to generate a signal in the delay-time domain. Then, a zero-padding section can be generated at the beginning of the data frame through a channel equalizer, and the signal in the delay-time domain can be multiplied by an equalization matrix column by column to generate a transmission signal.

[0089] In addition, regardless of the modulation method used, it can be applied to all communication systems that generate a zero-padding section at the beginning of the data frame of the signal in the delay-time domain at the transmitter and generate a transmission signal by multiplying the signal in the delay-time domain by an equalization matrix column by column.

[0090] In addition, although it has been described here that a transmission signal is generated by multiplying a signal in the delay-time domain by an equalization matrix column by column, it is not limited thereto, and a transmission signal may also be generated by multiplying a signal in the delay-Doppler domain or frequency-time domain by an equalization matrix column by column.

[0091] Figure 10 is a graph comparing the BER (Bit Error Rate) performance of a conventional OTFS communication system and the OTFS communication system of the present invention in a multi-user environment. The comparison is made for a case where there are four users and the vehicle speed is 500 km / h.

[0092] Referring to FIG. 10, it can be seen that the existing OTFS communication system (post-equalized) cannot overcome high mobility in a multi-user environment and has a deteriorated BER performance, whereas the OTFS communication system (pre-equalized) of the present invention maintains BER performance even in a multi-user environment.

[0093] Figure 11 is a graph comparing the PAPR (Peak to Average Power Ratio) performance of a conventional OTFS communication system and the OTFS communication system of the present invention. In Figure 11, the solid line represents the PAPR performance of the conventional OTFS communication system, and the dotted line represents the PAPR performance of the OTFS communication system of the present invention.

[0094] Looking at Figure 11, it can be seen that the OTFS communication system of the present invention has almost no difference in PAPR performance from that of the existing OTFS communication system, even though the transmitter transmits the signal after performing channel equalization in advance.

[0095] Figure 12 is a flowchart illustrating a communication method of a communication system according to one embodiment of the present invention. While the illustrated flowchart depicts the method as divided into multiple steps, at least some of the steps may be performed in reverse order, combined with other steps and performed together, omitted, divided into substeps, or performed with one or more additional steps not illustrated.

[0096] Referring to FIG. 12, the transmitter (102) can generate a zero padding section at the frontmost section of a data frame in the delay-time domain (S 101). Next, the transmitter (102) can obtain channel information between the transmitter (102) and the receiver (104) and generate an equalization matrix based on the obtained channel information (S 103).

[0097] Next, the transmitter (102) can generate a transmission signal by multiplying the signal in the delay-time domain by an equalization matrix column by column (S 105). Next, the transmitter (102) can transmit the pre-equalized transmission signal to the receiver (104) (S 107).

[0098] FIG. 13 is a block diagram illustrating a computing environment (10) including a computing device suitable for use in exemplary embodiments. In the illustrated embodiment, each component may have different functions and capabilities other than those described below, and may include additional components other than those described below.

[0099] The illustrated computing environment (10) includes a computing device (12). In one embodiment, the computing device (12) may be a transmitter (102). Additionally, the computing device (12) may be a receiver (104).

[0100] A computing device (12) includes at least one processor (14), a computer-readable storage medium (16), and a communication bus (18). The processor (14) may cause the computing device (12) to operate according to the exemplary embodiments mentioned above. For example, the processor (14) may execute one or more programs stored in the computer-readable storage medium (16). The one or more programs may include one or more computer-executable instructions, which, when executed by the processor (14), may be configured to cause the computing device (12) to perform operations according to the exemplary embodiments.

[0101] A computer-readable storage medium (16) is configured to store computer-executable instructions or program code, program data, and / or other suitable forms of information. A program (20) stored in the computer-readable storage medium (16) includes a set of instructions executable by the processor (14). In one embodiment, the computer-readable storage medium (16) may be a memory (volatile memory such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, any other form of storage medium that can be accessed by the computing device (12) and store desired information, or a suitable combination thereof.

[0102] A communication bus (18) interconnects various other components of the computing device (12), including the processor (14) and computer-readable storage media (16).

[0103] The computing device (12) may also include one or more input / output interfaces (22) that provide interfaces for one or more input / output devices (24) and one or more network communication interfaces (26). The input / output interfaces (22) and the network communication interfaces (26) are connected to the communication bus (18). The input / output devices (24) may be connected to other components of the computing device (12) via the input / output interfaces (22). Exemplary input / output devices (24) may include input devices such as pointing devices (such as a mouse or a trackpad), a keyboard, a touch input device (such as a touchpad or a touchscreen), a voice or sound input device, various types of sensor devices and / or photographing devices, and / or output devices such as display devices, printers, speakers and / or network cards. The exemplary input / output devices (24) may be included within the computing device (12) as a component constituting the computing device (12), or may be connected to the computing device (12) as a separate device distinct from the computing device (12).

[0104] While representative embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications to the above-described embodiments are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims set forth below but also by equivalents thereof.

Claims

1. One or more processors, and A method performed in a computing device having a memory storing one or more programs executed by one or more processors, and as a communication method for transmitting a signal of a transmitter in a communication system using pre-channel equalization, A step of generating a zero padding interval or a CP (Cyclic Prefix) interval at the frontmost interval of a data frame in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain; and A communication method comprising the step of generating a transmission signal by performing pre-equalization on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

2. In claim 1, The above pre-equalization is, A communication method, wherein compensation is performed in advance in a direction opposite to the spreading of data that will occur in a channel between the transmitter and the receiver before transmitting a signal from the transmitter to the receiver.

3. In claim 2, The step of generating the above transmission signal is: A step of obtaining channel information between the transmitter and the receiver to receive the transmission signal; A step of generating an equalization matrix based on the above channel information; and A communication method, comprising the step of generating the transmission signal by multiplying the equalization matrix by a signal of any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, column by column.

4. In claim 3, The above equalization matrix (H pre ) is a communication method generated by the following mathematical expression 1 or mathematical expression 2. (Mathematical formula 1) (Mathematical formula 2) : Channel matrix for the nth column of the signal matrix in the delay-time domain : Hermitian matrix of : The variance of the noise in that channel : Identity matrix corresponding to the length M of the nth column of the signal matrix in the delay-time domain 5. In claim 4, The step of generating the above transmission signal is to multiply the equalization matrix column by column by the following mathematical expression 3 or mathematical expression 4 to generate the transmission signal ( ) and generates a matrix of transmission signals by concatenating each column of the transmission signal. (Mathematical formula 3) (Mathematical formula 4) : The nth column of the signal matrix in the delay-time domain 6. In claim 2, The above communication system is an OTFS (Orthogonal Time Frequency Space) communication system, The above communication method, prior to the step of generating the zero padding interval or CP interval, A step of receiving data bits, digitally modulating them, and mapping the modulated data symbols into the delay-Doppler domain; A step of converting the signal in the above delay-Doppler domain into the frequency-time domain by using ISFFT (Inverse Symplectic Fast Fourier Transform); and A communication method further comprising the step of generating a signal in the delay-time domain by performing an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain.

7. In claim 2, The above communication system is an OFDM (Orthogonal Frequency Division Multiplexing) communication system, The above communication method, prior to the step of generating the zero padding interval or CP interval, A step of receiving data bits, digitally modulating them, and mapping the modulated data symbols into the frequency-time domain; and A communication method further comprising the step of generating a signal in the delay-time domain by performing an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain.

8. One or more processors, and A method performed in a computing device having a memory storing one or more programs executed by one or more processors, and as a communication method for receiving a signal by a receiver in a communication system using pre-channel equalization, A communication method, comprising the step of generating a zero padding interval or a CP (Cyclic Prefix) interval at the front end of a data frame from a transmitter in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, and receiving a transmission signal on which pre-equalization has been performed on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

9. A communication system including a transmitter and a receiver and utilizing pre-channel equalization, The above transmitter, A communication system comprising a channel equalizer for generating a zero padding interval or a CP (Cyclic Prefix) interval at the front end of a data frame of any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, and performing pre-equalization on a signal of any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain to generate a transmission signal.

10. In claim 9, The above pre-equalization is, A communication system, wherein prior to transmitting a signal from the transmitter to the receiver, compensation is performed in advance in a direction opposite to the spreading of data that will occur in a channel between the transmitter and the receiver.

11. In claim 10, The above channel equalizer, A communication system which obtains channel information between the transmitter and the receiver to receive the transmission signal, generates an equalization matrix based on the channel information, and multiplies the equalization matrix by a signal of any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain column by column to generate the transmission signal.

12. In claim 11, The above equalization matrix (H pre ) is a communication system generated by the following mathematical expression 1 or mathematical expression 2. (Mathematical formula 1) (Mathematical formula 2) : Channel matrix for the nth column of the signal matrix in the delay-time domain : Hermitian matrix of : The variance of the noise in that channel : Identity matrix corresponding to the length M of the nth column of the signal matrix in the delay-time domain 13. In claim 12, The above channel equalizer, The transmission signal is obtained by multiplying the equalization matrix column by column by the following mathematical expression 3 or mathematical expression 4. ) and generates a matrix of transmission signals by concatenating each column of the transmission signal. (Mathematical formula 3) (Mathematical formula 4) : The nth column of the signal matrix in the delay-time domain 14. In claim 10, The above communication system is an OTFS (Orthogonal Time Frequency Space) communication system, The above transmitter, prior to generating the zero padding interval or CP interval, A communication system that receives data bits, digitally modulates them, maps the modulated data symbols to the delay-Doppler domain, converts the signal in the delay-Doppler domain into the frequency-time domain by performing an Inverse Symplectic Fast Fourier Transform (ISFFT) transform, and generates a signal in the delay-time domain by performing an Inverse Fast Fourier Transform (IFFT) transform on the signal in the frequency-time domain.

15. In claim 14, The above receiver, A communication system which receives the pre-equalized transmission signal from the transmitter, converts the received signal in the delay-time domain into the frequency-time domain by performing an FFT (Fast Fourier Transform) transform, and generates an original data estimation signal in the delay-Doppler domain by performing an SFFT (Symplectic Fast Fourier Transform) transform on the signal in the frequency-time domain.

16. In claim 10, The above communication system is an OFDM (Orthogonal Frequency Division Multiplexing) communication system, The above transmitter, prior to generating the zero padding interval or CP interval, A communication system that receives data bits, digitally modulates them, maps the modulated data symbols into the frequency-time domain, and performs an IFFT (Inverse Fast Fourier Transform) on the signal in the frequency-time domain to generate a signal in the delay-time domain.

17. A communication system including a transmitter and a receiver and utilizing pre-channel equalization, The above receiver, A communication system for receiving a transmission signal in which a zero padding interval or a CP (Cyclic Prefix) interval is generated at the front end of a data frame from the transmitter in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, and in which pre-equalization is performed on a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain.

18. In claim 17, The above pre-equalization is, A communication system, wherein prior to transmitting a signal from the transmitter to the receiver, compensation is performed in advance in a direction opposite to the spreading of data that will occur in a channel between the transmitter and the receiver.

19. One or more processors, and A method performed in a computing device having a memory storing one or more programs executed by one or more processors, and as a communication method for transmitting a signal of a transmitter in a communication system using pre-channel equalization, A step of obtaining channel information between the transmitter and receiver; A step of generating an equalization matrix based on the above channel information; and A communication method, comprising the step of generating a transmission signal by multiplying the equalization matrix by a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, column by column.

20. One or more processors, and A method performed on a computing device having a memory storing one or more programs executed by one or more processors, A communication method using pre-channel equalization of each transmitter, which is a user terminal, in a communication system of an uplink multi-user scenario, A step of obtaining channel information between the transmitter and receiver; A step of generating an equalization matrix based on the above channel information; and A communication method, comprising the step of generating a transmission signal by multiplying the equalization matrix by a signal in any one of the delay-Doppler domain, the frequency-time domain, and the delay-time domain, column by column.

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