CN109889465A - A peak-to-average ratio suppression method, device, electronic device and readable storage medium - Google Patents

Abstract

Embodiments of the present invention provide a peak-to-average ratio suppression method, device, electronic device, and readable storage medium, which are applied to the technical field of wireless communications. The method includes: according to a preset complementary cumulative distribution function CCDF value B and a CCDF function, Calculate the CDF value Pr of the cumulative distribution function; according to the CDF value Pr, the preset PAPR threshold γ, and the preset limit value calculation formula, the limit value A of the companding function is obtained, and according to the limit value A, the companding function is obtained. The spreading function compands the OFDM signal to obtain a companded OFDM signal. Compared with the prior art, the present invention can reduce the distortion of the OFDM signal.

Description

A peak-to-average ratio suppression method, device, electronic device and readable storage medium

technical field

The present invention relates to the technical field of wireless communication, and in particular, to a peak-to-average ratio suppression method, device, electronic device and readable storage medium.

Background technique

In OFDM (Orthogonal Frequency Division Multiplexing, Orthogonal Frequency Division Multiplexing) communication, due to the influence of nonlinear power amplification, when the PAPR (Peak to Average Power Ratio, peak-to-average ratio) of the OFDM signal is too high, it will lead to The OFDM signal will have large distortion, which will seriously affect the performance of the system. Therefore, how to reduce the PAPR of the OFDM signal is a key issue, which can help the OFDM system to improve the capability of resisting the nonlinear interference of the power amplifier, and is of great significance for improving the performance of the OFDM system.

Existing companding peak-to-average ratio suppression methods include: limiting method, linear companding method, and nonlinear companding method, etc. The limiting method is to directly compress the large-amplitude signal, and compress the signal whose amplitude exceeds a certain value. Limited to a fixed value, this method will result in a reduction in the average power of the signal, resulting in greater distortion of the signal. The linear companding method uses a piecewise linear function to compand the amplitude of the OFDM signal. However, because the linear companding function does not sufficiently suppress signals with larger amplitudes, the function of this method has limited PAPR suppression effect on the OFDM signal. The nonlinear companding method is to perform nonlinear transformation on the amplitude of the OFDM signal. However, since the amplitude of the OFDM signal undergoes nonlinear distortion, this method will lead to a large distortion of the OFDM signal. It can be seen that the existing peak-to-average ratio suppression method causes the OFDM signal to have large distortion.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present invention is to provide a peak-to-average ratio suppression method, apparatus, electronic device, and readable storage medium, so as to reduce the distortion of the OFDM signal. The specific technical solutions are as follows:

The embodiment of the present invention provides a peak-to-average ratio suppression method, and the method includes:

According to the preset complementary cumulative distribution function CCDF value B and CCDF function: 1-Pr ^N =B, calculate the cumulative distribution function CDF value Pr, where N represents the number of samples of the OFDM signal, and Pr ^N represents the OFDM signal The probability that the peak-to-average ratio PAPR ≤ the preset PAPR threshold γ;

According to the CDF value Pr, the preset PAPR threshold γ and the preset limit value calculation formula:

Obtain the limit value A of the companding function,

in, k represents the slope of the companding function, k is obtained according to the formula of the average power conservation of the signal before and after companding, k>1, e represents the irrational number e, and σ represents the variance of the OFDM signal;

According to the clipping value A, the companding function is obtained: x represents the amplitude value of the OFDM signal, and y represents the amplitude value after companding the OFDM signal;

The OFDM signal is companded according to the companding function to obtain a companded OFDM signal.

Optionally, after the companding of the OFDM signal according to the companding function to obtain the companded OFDM signal, the method further includes:

According to the mean squared error formula:

Calculate the power mean square error of the companded OFDM signal erf(A) represents the error function of the limit value A, x _n represents the amplitude value of the n-th sample point signal, y _n represents the amplitude value of the n-th sample point signal after companding, and σ ² represents the the average power of the OFDM signal;

like is greater than the preset error threshold, the limit value A is updated to obtain the updated limit value A', so that the mean square error of the power obtained according to the updated limit value A' not greater than the preset error threshold;

According to the updated limit value A', the companding function is updated to obtain the updated companding function:

The OFDM signal is companded according to the updated companding function to obtain an updated companded OFDM signal.

Optionally, the method for determining the preset limit value calculation formula includes:

according to get The CDF value Pr represents the probability that the PAPR of each sample signal is ≤ the preset PAPR threshold γ, P{} represents the probability operator, and σ ² represents the average power of the OFDM signal;

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Optionally, the peak-to-average ratio suppression method according to the embodiment of the present invention further includes:

According to the conservation formula of signal average power before and after companding: and the companding function: get

Among them, f(x) is the probability distribution density function obeyed by the amplitude value x of the OFDM signal, σ ² represents the average power of the OFDM signal.

An embodiment of the present invention provides a peak-to-average ratio suppression device, the device comprising:

The CDF value calculation module is used to calculate the CDF value Pr of the cumulative distribution function according to the preset complementary cumulative distribution function CCDF value B and the CCDF function: 1-Pr ^N =B, where N represents the number of samples of the OFDM signal, Pr ^N represents the probability that the peak-to-average ratio PAPR of the OFDM signal is less than or equal to the preset PAPR threshold γ;

The limit value calculation module is used for calculating the formula according to the CDF value Pr, the preset PAPR threshold γ and the preset limit value:

Obtain the limit value A of the companding function,

in, k represents the slope of the companding function, k is obtained according to the formula of the average power conservation of the signal before and after companding, k>1, e represents the irrational number e, and σ represents the variance of the OFDM signal;

A companding function determination module, configured to obtain the companding function according to the clipping value A: x represents the amplitude value of the OFDM signal, and y represents the amplitude value after companding the OFDM signal;

A signal companding module, configured to compand the OFDM signal according to the companding function to obtain a companded OFDM signal.

Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The mean square error calculation module is used to calculate the mean square error according to the formula:

Calculate the power mean square error of the companded OFDM signal erf(A) represents the error function of the limit value A, x _n represents the amplitude value of the n-th sample point signal, y _n represents the amplitude value of the n-th sample point signal after companding, and σ ² represents the the average power of the OFDM signal;

Limit value update module, used if is greater than the preset error threshold, the limit value A is updated to obtain the updated limit value A', so that the mean square error of the power obtained according to the updated limit value A' not greater than the preset error threshold;

The companding function updating module is configured to update the companding function according to the updated amplitude limit value A' to obtain the updated companding function:

A recompanding module, configured to perform companding on the OFDM signal according to the updated companding function to obtain an updated companded OFDM signal.

Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The module for determining the calculation formula of the preset limit value is used to determine the get The CDF value Pr represents the probability that the PAPR of each sample signal is ≤ the preset PAPR threshold γ, P{} represents the probability operator, and σ ² represents the average power of the OFDM signal;

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Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The module for determining the relationship between the slope and the limit value is used for the conservation formula of the average power of the signal before and after companding: and the companding function: The slope k and the limit value A are obtained to satisfy the formula:

Among them, f(x) is the probability distribution density function obeyed by the amplitude value x of the OFDM signal, σ ² represents the average power of the OFDM signal.

An embodiment of the present invention provides an electronic device, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

the memory for storing computer programs;

The processor is configured to implement the steps of any of the above-mentioned peak-to-average ratio suppression methods when executing the program stored in the memory.

An embodiment of the present invention provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, any one of the above-mentioned peak-to-average ratio suppression methods is implemented. step.

The technical solutions provided by the embodiments of the present invention may include the following beneficial effects. Under the condition that the preset CCDF value and the preset PAPR threshold are satisfied, the limit value of the companding function is calculated by the preset limit value calculation formula, and the limit value is calculated according to the limit value. value to get the companding function. Because the companding function in this embodiment of the present application can limit the amplitude of the OFDM signal with a large amplitude value, and expand the OFDM signal with a small amplitude value, so that the average power of the OFDM signal before and after companding is equal. While reducing the PAPR threshold of the OFDM signal, the distortion of the OFDM signal can be reduced. Of course, it is not necessary for any product or method of the present invention to achieve all of the advantages described above at the same time.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Fig. 1 is a kind of flow chart of the peak-to-average ratio suppression method of the embodiment of the present invention;

Fig. 2 is the change curve diagram of the preset PAPR threshold value and the mean square error respectively with the limit value of the embodiment of the present invention;

Fig. 3 is another kind of flow chart of the peak-to-average ratio suppression method of the embodiment of the present invention;

4 is a structural diagram of a peak-to-average ratio suppression device according to an embodiment of the present invention;

FIG. 5 is a structural diagram of an electronic device according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Referring to Fig. 1, Fig. 1 is a flow chart of a method for suppressing peak-to-average ratio according to an embodiment of the present invention, comprising the following steps:

S101, according to the preset complementary cumulative distribution function CCDF value B and CCDF function: 1-Pr ^N =B, calculate the cumulative distribution function CDF value Pr, where N represents the number of samples of the OFDM signal, and Pr ^N represents that the PAPR of the OFDM signal≤preset PAPR The probability of the threshold γ.

Specifically, the complementary cumulative distribution function represents the probability that the peak-to-average value in the signal transmission system exceeds a certain preset threshold (the preset PAPR threshold γ in this embodiment of the present application), and the preset CCDF value B represents that the peak-to-average ratio in the OFDM signal is greater than the preset value. Assuming the probability of the PAPR threshold γ, the OFDM signal can be a time domain signal after inverse fast Fourier transform. The PAPR of an OFDM signal can be expressed as:

x _n represents the amplitude value of the signal at the nth sample point, and E(.) is an operator for mathematical expectation.

In the OFDM signal, the probability that the peak-to-average ratio PAPR of the OFDM signal is less than or equal to the preset PAPR threshold γ refers to the probability that the ratio of the instantaneous power to the average power of all sample signals is less than γ. Because before companding, all sample signals are independent and identically distributed, so after companding, all sample signals are also independent and identically distributed. Pr ^N represents the probability that the PAPR of the OFDM signal ≤ the preset PAPR threshold γ, and Pr represents the probability that the PAPR of each sample signal ≤ the preset PAPR threshold γ.

In this embodiment of the present invention, the preset CCDF value B may be set according to different communication quality requirements, for example, may be 10 ^-4 , 10 ^-3 , 10 ^-2 , and the like. In general, the PAPR threshold refers to the initial PAPR threshold γ ₀ , and γ ₀ can be processed according to the formula: 10*lgγ=γ ₀ to obtain the preset PAPR threshold γ in the embodiment of the present invention, that is, the present invention The preset PAPR threshold γ of an embodiment is a value after processing.

For example, when the subcarrier N of the OFDM signal is 64, the probability that the initial PAPR exceeds 5 dB is required to be no higher than 10 ^-4 . At this time, γ ₀ =5dB, 10*lgγ=5, CCDF value B=10 ⁻⁴ , and 1-Pr ⁶⁴ =10 ⁻⁴ , so the value of Pr can be obtained.

S102, according to the CDF value Pr, the preset PAPR threshold γ and the preset limit value calculation formula:

Obtain the limit value A of the companding function,

in, k represents the slope of the companding function, k is obtained according to the formula of the average power conservation of the signal before and after companding, k>1, e represents the irrational number e, and σ represents the variance of the OFDM signal.

In the embodiment of the present invention, since the average power of the OFDM signal before companding and after companding is conserved, the average power conservation formula of the signal before companding and after companding can be used as follows: and the companding function: get

Among them, f(x) is the probability distribution density function that the amplitude value x of the OFDM signal obeys. In the OFDM signal, the time domain signal obeys the Rayleigh distribution, that is, σ ² represents the average power of the OFDM signal.

Since the CDF value Pr can be obtained according to S101 and the preset PAPR threshold γ is known, then according to the preset limit value calculation formula, the limit value A of the companding function can be obtained. The method for determining the calculation formula of the preset limit value includes:

according to get The CDF value Pr represents the probability that the PAPR of each sample signal is ≤ the preset PAPR threshold γ, P{} represents the probability operator, and σ ² represents the average power of the OFDM signal;

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In addition, the relationship between the preset PAPR threshold γ and the limit value A can be drawn by MATLAB software, as shown in Figure 2. In the actual setting of the limit value A, the limit is inversely solved by the calculation formula of the preset limit value. The process of the amplitude value A is more complicated, therefore, the amplitude limit value A can be set according to Fig. 2 . For example, when the preset PAPR threshold γ is 3.98, the clipping value A can be set to 2.

S103, according to the limit value A, obtain the companding function: x represents the amplitude value of the OFDM signal, and y represents the amplitude value after companding the OFDM signal.

Specifically, after obtaining the limit value A, according to Get the value of k, and then get the companding function.

S104, companding the OFDM signal according to the companding function to obtain a companded OFDM signal.

Specifically, if the amplitude value of the OFDM signal is greater than A, the amplitude value of the OFDM signal is set to A, and the phase of the OFDM signal remains unchanged; if the amplitude value of the OFDM signal is not greater than A, the amplitude value of the OFDM signal is expanded to k times , the phase of the OFDM signal does not change.

In addition, since the companding function is used at the transmitting end of the OFDM system, that is, the transmitting end can compress the OFDM signal and send the companded OFDM signal to the receiving end, and the receiving end can compress the received companded OFDM signal. The signal is decompressed and expanded.

In the peak-to-average ratio suppression method of the embodiment of the present invention, when the preset CCDF value and the preset PAPR threshold are satisfied, the limit value of the companding function is calculated by the preset limit value calculation formula, and the compression value is obtained according to the limit value. extension function. Since the companding function in the embodiment of the present application is a function of linear and limiting, that is, the OFDM signal with a large amplitude value can be limited, and the OFDM signal with a small amplitude value can be expanded, so that the companding function before and after companding can be achieved. The average power of the OFDM signals is equal, therefore, while reducing the PAPR threshold of the OFDM signal, the distortion of the OFDM signal can be reduced.

Referring to FIG. 3, FIG. 3 is another flowchart of the peak-to-average ratio suppression method according to the embodiment of the present invention. After the embodiment S104 in FIG. 1, the following steps are further included:

S301, according to the mean square error formula:

Calculate the power mean square error of the companded OFDM signal erf(A) represents the error function of the slice value A, x _n represents the amplitude value of the n-th sample point signal, and _yn represents the amplitude value of the n-th sample point signal after companding.

In the embodiment of the present invention, when the preset PAPR threshold γ is required to be low, the corresponding amplitude limit value A will also decrease accordingly, and the corresponding MSE (mean-square error, mean square error) will increase. At this time, the MSE of the OFDM signal can be guaranteed first, and on the premise of ensuring the MSE, the smallest amplitude limiting value A is found, so as to ensure the PAPR of the OFDM signal as much as possible. Therefore, the power mean square error of the companded OFDM signal can be calculated according to the mean square error formula

S302, judge Is it greater than the preset error threshold.

In this step, if If it is greater than the preset error threshold, it indicates that the companded OFDM signal obtained by the companding function is relatively large and does not meet the requirements, and S203 is executed. Otherwise, it indicates that the companded OFDM signal obtained by the companding function meets the requirements, that is, the companding function is available. The preset error threshold is a value set according to different communication quality requirements, which is not limited here.

S303, update the limit value A to obtain the updated limit value A', so that the mean square error of the power obtained according to the updated limit value A' not greater than the preset error threshold.

Specifically, as mentioned above, the smaller the clipping value A is, the larger the obtained MSE is. Then, when the clipping value A is updated, the size of the clipping value A can be increased, and recalculation can be performed according to the increased value. Power Mean Square Error If it is not satisfied, continue to increase the size of the limit value A until the power mean square error not greater than the preset error threshold. That is to say, make the final updated clipping value A' as small as possible and satisfy the power mean square error not greater than the preset error threshold. Therefore, the relationship between MSE and the limit value A can be drawn in Figure 2 at the same time, if If it is greater than the preset error threshold, MSE can be guaranteed first, and then the updated limit value A' is determined according to the relationship between the MSE and the limit value A. For example, if the preset error threshold is 0.0001, when the limit value A is 2, the obtained power mean square error is 0.01, which is greater than the preset error threshold of 0.0001. Therefore, according to the preset error threshold of 0.0001 and the relationship between MSE and the limit value A, the updated limit value A' is 2.6.

S304, update the companding function according to the updated amplitude limiting value A' to obtain the updated companding function:

S305, companding the OFDM signal according to the updated companding function to obtain an updated companded OFDM signal.

It can be seen that, in the peak-to-average ratio suppression method of the embodiment of the present application, the PAPR of the OFDM signal is given priority, the limit value A is calculated according to the preset PAPR threshold γ, and then the power mean square error is calculated according to the limit value A exist If it does not meet the requirements, then determine the limit value A according to the relationship between MSE and the limit value A. At this time, priority is given to ensuring the MSE of the signal, and on the premise of ensuring the MSE, the smallest amplitude limiting value A is found, so as to ensure the PAPR of the signal as much as possible.

Corresponding to the above method embodiments, an embodiment of the present invention provides a peak-to-average ratio suppression device. Referring to FIG. 4 , FIG. 4 is a structural diagram of the peak-to-average ratio suppression device according to an embodiment of the present invention, including:

The CDF value calculation module 401 is configured to calculate the CDF value Pr of the cumulative distribution function according to the preset complementary cumulative distribution function CCDF value B and the CCDF function: 1-Pr ^N =B, where N represents the number of samples of the OFDM signal. , Pr ^N represents the probability that the PAPR of the OFDM signal is less than or equal to the preset PAPR threshold γ;

The limit value calculation module 402 is used for calculating the formula according to the CDF value Pr, the preset PAPR threshold γ and the preset limit value:

Obtain the limit value A of the companding function,

in, k represents the slope of the companding function, k>1, k is obtained from the formula of the average power conservation of the signal before and after companding, e represents the irrational number e, and σ represents the variance of the OFDM signal;

The companding function determination module 403 is configured to obtain the companding function according to the amplitude limiting value A: x represents the amplitude value of the OFDM signal, and y represents the amplitude value after companding the OFDM signal;

The signal companding module 404 is used for companding the OFDM signal according to the companding function to obtain the companded OFDM signal.

In the peak-to-average ratio suppression device of the embodiment of the present invention, when the preset CCDF value and the preset PAPR threshold are satisfied, the limit value of the companding function is calculated by the preset limit value calculation formula, and the compression value is obtained according to the limit value. extension function. Since the companding function in the embodiment of the present application is a function of linear and limiting, that is, the OFDM signal with a large amplitude value can be limited, and the OFDM signal with a small amplitude value can be expanded, so that the companding function before and after companding can be achieved. The average power of the OFDM signals is equal, therefore, while reducing the PAPR threshold of the OFDM signal, the distortion of the OFDM signal can be reduced.

Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The mean square error calculation module is used to calculate the mean square error according to the formula:

Calculate the power mean square error of the companded OFDM signal erf(A) represents the error function of the amplitude limiting value A, x _n represents the amplitude value of the n-th sample point signal, y _n represents the amplitude value after companding the n-th sample point signal,;

Limit value update module, used if greater than the preset error threshold, update the limit value A to obtain the updated limit value A', so that the mean square error of the power obtained according to the updated limit value A' not greater than the preset error threshold, σ ² represents the average power of the OFDM signal;

The companding function updating module is used to update the companding function according to the updated amplitude limit value A' to obtain the updated companding function:

The recompanding module is used for companding the OFDM signal according to the updated companding function to obtain an updated companded OFDM signal.

Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The module for determining the calculation formula of the preset limit value is used to determine the get The CDF value Pr represents the probability that the PAPR of each sample signal is ≤ the preset PAPR threshold γ, P{} represents the probability operator, and σ ² represents the average power of the OFDM signal;

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Optionally, the peak-to-average ratio suppression device in the embodiment of the present invention further includes:

The module for determining the relationship between the slope and the limit value is used for the conservation formula of the average power of the signal before and after companding: and the companding function: The slope k and the limit value A are obtained to satisfy the formula:

Among them, f(x) is the probability distribution density function that the amplitude value x of the OFDM signal obeys, σ ² represents the average power of the OFDM signal.

Regarding the apparatus in the above-mentioned embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be described in detail here.

An embodiment of the present invention further provides an electronic device. Referring to FIG. 5, FIG. 5 is a structural diagram of an electronic device according to an embodiment of the present invention, including: a processor 501, a communication interface 502, a memory 503, and a communication bus 504, wherein the processing The device 501, the communication interface 502, and the memory 503 complete the communication with each other through the communication bus 504;

a memory 503 for storing computer programs;

The processor 501 is configured to implement the steps of any of the above-mentioned peak-to-average ratio suppression methods when executing the program stored in the memory 503 .

It should be noted that the communication bus 504 mentioned in the above electronic device may be a PCI (Peripheral Component Interconnect, peripheral component interconnect standard) bus or an EISA (Extended Industry Standard Architecture, extended industry standard architecture) bus or the like. The communication bus 504 can be divided into an address bus, a data bus, a control bus, and the like. For ease of presentation, only one thick line is used in FIG. 5, but it does not mean that there is only one bus or one type of bus.

The communication interface 502 is used for communication between the above-mentioned electronic device and other devices.

The memory 503 may include a RAM (Random Access Memory, random access memory), and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

The above-mentioned processor 501 may be a general-purpose processor, including: CPU (Central Processing Unit, central processing unit), NP (Network Processor, network processor), etc.; may also be DSP (Digital Signal Processing, digital signal processor), ASIC (Application Specific Integrated Circuit, Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array, Field Programmable Gate Array) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

In the electronic device of the embodiment of the present invention, by executing the program stored in the memory, the processor calculates the amplitude limit of the companding function by using the preset amplitude limit value calculation formula under the condition that the preset CCDF value and the preset PAPR threshold value are satisfied. value, and get the companding function according to the clipping value. Since the companding function in the embodiment of the present application is a function of linear and limiting, that is, the OFDM signal with a large amplitude value can be limited, and the OFDM signal with a small amplitude value can be expanded, so that the companding function before and after companding can be achieved. The average power of the OFDM signals is equal, therefore, while reducing the PAPR threshold of the OFDM signal, the distortion of the OFDM signal can be reduced.

An embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps of any of the above methods for suppressing peak-to-average ratio are implemented.

When the instructions stored in the computer-readable storage medium of the embodiment of the present invention are run on a computer, under the condition that the preset CCDF value and the preset PAPR threshold are satisfied, the limit of the companding function is calculated by the preset limit value calculation formula value, and get the companding function according to the clipping value. Since the companding function in the embodiment of the present application is a function of linear and limiting, that is, the OFDM signal with a large amplitude value can be limited, and the OFDM signal with a small amplitude value can be expanded, so that the companding function before and after companding can be achieved. The average power of the OFDM signals is equal, therefore, while reducing the PAPR threshold of the OFDM signal, the distortion of the OFDM signal can be reduced.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Each embodiment in this specification is described in a related manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. Especially, for the embodiments of the apparatus, electronic device and readable storage medium, since they are basically similar to the method embodiments, the description is relatively simple, and reference may be made to some descriptions of the method embodiments for related parts.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for peak-to-average power ratio suppression, the method comprising:

according to a preset complementary cumulative distribution function CCDF value B and a CCDF function: 1-Pr^NCalculating the CDF value Pr of the cumulative distribution function B, wherein N represents the number of sampling points of the OFDM signal, and Pr^NRepresenting the probability that the PAPR of the OFDM signal is less than or equal to a preset PAPR threshold value gamma;

according to the CDF value Pr, the preset PAPR threshold value gamma and a preset amplitude limiting value, calculating a formula:

the clipping value a of the companding function is obtained,

wherein,k represents the slope of the companding function, k is obtained according to the formula of the average power conservation of the signals before and after companding, and k is>1, e represents an irrational number e, and sigma represents the variance of the OFDM signal;

obtaining the companding function according to the amplitude limiting value A:x represents an amplitude value of the OFDM signal, and y represents an amplitude value obtained after companding the OFDM signal;

and carrying out companding on the OFDM signal according to the companding function to obtain the companded OFDM signal.

2. The method of claim 1, wherein after the companding the OFDM signal according to the companding function to obtain a companded OFDM signal, the method further comprises:

according to the mean square error formula:

calculating the power mean square error of the companded OFDM signal erf (A) error function representing clipping value A, x_nRepresenting amplitude values of the nth sample signal, y_nRepresenting the amplitude value, σ, of the n-th sample signal after companding²Representing the average power of the OFDM signal；

If it isIf the amplitude limiting value A is larger than the preset error threshold value, updating the amplitude limiting value A to obtain an updated amplitude limiting value A', so that the power mean square error is obtained according to the updated amplitude limiting value ANot greater than the preset error threshold;

updating the companding function according to the updated amplitude limit value A' to obtain an updated companding function:

and carrying out companding on the OFDM signal according to the updated companding function to obtain an updated companded OFDM signal.

3. The method for suppressing peak-to-average power ratio according to claim 1, wherein the method for determining the preset clipping value calculation formula comprises:

according toTo obtainThe CDF value Pr represents the probability that the PAPR of each sampling point signal is less than or equal to a preset PAPR threshold value gamma, P { } represents a probability operator, and sigma is²Representing an average power of the OFDM signal;

if it isThen

If it isThen

If it isThen

If it isThen

To obtain

4. The method of peak-to-average power ratio suppression according to claim 1, further comprising:

according to the formula of signal average power conservation before companding and after companding:and the companding function:to obtain

Wherein f (x) is a probability distribution density function to which the amplitude values x of the OFDM signal obey,σ²represents the average power of the OFDM signal.

5. A peak-to-average ratio suppression apparatus, comprising:

the CDF value calculating module is used for calculating the CDF value according to a preset complementary cumulative distribution function CCDF value B and a CCDF function: 1-Pr^NCalculating the CDF value Pr of the cumulative distribution function B, wherein N represents the number of sampling points of the OFDM signal, and Pr^NRepresenting the probability that the PAPR of the OFDM signal is less than or equal to a preset PAPR threshold value gamma;

and the amplitude limiting value calculating module is used for calculating a formula according to the CDF value Pr, the preset PAPR threshold value gamma and a preset amplitude limiting value:

the clipping value a of the companding function is obtained,

wherein,k represents the slope of the companding function, k is obtained according to the formula of the average power conservation of the signals before and after companding, and k is>1, e represents an irrational number e, and sigma represents the variance of the OFDM signal;

a companding function determining module, configured to obtain the companding function according to the amplitude limit value a:x represents an amplitude value of the OFDM signal, and y represents an amplitude value obtained after companding the OFDM signal;

and the signal companding module is used for companding the OFDM signal according to the companding function to obtain the companded OFDM signal.

6. The apparatus according to claim 5, further comprising:

a mean square error calculation module for, according to a mean square error formula:

calculating the power mean square error of the companded OFDM signal erf (A) error function representing clipping value A, x_nRepresenting amplitude values of the nth sample signal, y_nRepresenting the amplitude value, σ, of the n-th sample signal after companding²Representing an average power of the OFDM signal;

a clipping value update module for ifIf the amplitude limiting value A is larger than the preset error threshold value, updating the amplitude limiting value A to obtain an updated amplitude limiting value A', so that the power mean square error is obtained according to the updated amplitude limiting value ANot greater than the preset error threshold;

a companding function updating module, configured to update the companding function according to the updated amplitude limit value a', to obtain an updated companding function:

and the re-companding module is used for companding the OFDM signal according to the updated companding function to obtain an updated companded OFDM signal.

7. The apparatus according to claim 5, further comprising:

a preset amplitude limiting value calculation formula determination module for determining the preset amplitude limiting value according toTo obtainThe CDF value Pr represents the probability that the PAPR of each sampling point signal is less than or equal to the preset PAPR threshold value gamma, P { } represents a probability operator, and sigma represents a probability operator²Representing an average power of the OFDM signal;

if it isThen

If it isThen

If it isThen

If it isThen

To obtain

8. The apparatus according to claim 5, further comprising:

the slope and amplitude limiting value relation determining module is used for determining the relation between the slope and the amplitude limiting value according to a signal average power conservation formula before companding and after companding:and the companding function:the obtained slope k and the amplitude limiting value A satisfy the formula:

wherein f (x) is a probability distribution density function to which the amplitude values x of the OFDM signal obey,σ²represents the average power of the OFDM signal.

9. An electronic device, comprising: the system comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are communicated with each other through the communication bus;

the memory is used for storing a computer program;

the processor is configured to implement the steps of the peak-to-average ratio suppressing method according to any one of claims 1 to 4 when executing the program stored in the memory.

10. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method for peak-to-average ratio suppression according to any one of claims 1 to 4 are implemented.