A method and apparatus for reducing the peak-to-average power ratio of a micro LED optical communication system

Abstract

This invention discloses a method and apparatus for reducing the peak-to-average power ratio (PAPR) of a micro LED optical communication system. The method includes: precoding modulation data of a first user and modulation data of a second user at the transmitter of a VLC system using a precoding matrix to obtain precoded output signals for the first and second users, respectively; combining the precoded output signals of the first and second users based on a power allocation factor and the total power of the precoded output signals of the first and second users to obtain a precoded frequency domain signal; extending the precoded frequency domain signal into an extended frequency domain signal with Hermitian symmetry; performing an inverse fast Fourier transform on the extended frequency domain signal to obtain a precoded time domain signal; performing μ-law compression on the precoded time domain signal to obtain a compressed signal; and calculating the PAPR based on the compressed signal. This invention can effectively reduce PAPR.

Description

Technical Field

[0001] This invention relates to the field of visible light communication, and more specifically to a method and apparatus for reducing the peak-to-average power ratio of a micro LED optical communication system. Background Technology

[0002] With the increasing demand for data communication, traditional RF (radio frequency) communication technology can no longer meet the requirements of high-speed, high-capacity transmission. Visible light communication (VLC), as an emerging data transmission method, utilizes LED light-emitting devices to transmit data. Due to its abundant spectrum resources, low cost, and immunity to electromagnetic interference, it has become a strong candidate to overcome the limitations of traditional communication. Orthogonal frequency division multiplexing (OFDM) has become the mainstream modulation technology in VLC systems due to its high data transmission rate and resistance to multipath interference. However, the high PAPR (parallel amplitude resonant frequency) problem of OFDM technology widely used in VLC systems can lead to nonlinear distortion of LEDs, thus affecting the efficiency and signal quality of the entire system.

[0003] Currently, various techniques have been proposed to reduce PAPR in OFDM systems, such as peak clipping and filtering, selective signal mapping (SLM), and partial transmission sequence (PTS). However, these techniques all increase system complexity or sacrifice some data transmission efficiency. In VLC environments, due to the inherent characteristics of their chip structure and materials, LEDs exhibit significant nonlinear characteristics under large-signal driving, especially under high-power driving, where this nonlinearity becomes more pronounced. Peak clipping reduces PAPR by directly reducing the peak signal, but in VLC systems using micro-LEDs as the light source, this method further exacerbates the nonlinear distortion of the optical signal because the high-frequency components generated after peak clipping are amplified by the nonlinearity of the micro-LEDs. Selective signal mapping (SLM) and partial transmission sequence (PTS) reduce PAPR by performing multiple transformations on the input signal to select the signal with the lowest PAPR for transmission, but their implementation requires complex signal processing circuits at both the receiver and transmitter, leading to increased system cost and power consumption.

[0004] In wireless communication, transmitters need to handle long-distance transmission, making the efficiency of power amplifiers particularly important. Excessively high PAPR (Power Amplifier Ratio) leads to a reduction in the power amplifier's output power, thus affecting communication quality and coverage. Reducing PAPR is achieved by pre-distorting the signal at the transmitting end. In the VLC (Video Communication Center) field, since LED-VLC is primarily used for short-range communication, PAPR reduction techniques directly impact the LED's operational stability and also affect the efficiency of the communication system. Therefore, it is mainly achieved by limiting the modulation amplitude of high-peak signals to keep the LED operating within a reasonable linear range.

[0005] Furthermore, the application of Multiple-Input Multiple-Output (MIMO) technology in VLC systems allows for the simultaneous transmission of multiple signals to increase transmission rate and channel capacity, which further exacerbates the PAPR problem. This is because in MIMO-OFDM systems, the superposition of multiple signals can lead to higher peak power, thus increasing the severity of the PAPR problem.

[0006] Existing PAPR reduction technologies face the dual challenges of complexity and processing efficiency when dealing with complex MIMO-OFDM systems. In actual deployment, these technologies often require special hardware designs, such as adding linearization processing modules, which not only increases costs but also reduces the system's processing efficiency.

[0007] VLC systems based on micro-LEDs are considered an effective way to improve VLC system performance due to their faster modulation speed. However, compared to traditional LED light sources, micro-LEDs have a higher emission bandwidth, which enables them to support higher data transmission rates and are suitable for higher-order modulation schemes (such as QAM-OFDM). This high emission bandwidth allows micro-LEDs to transmit signals over a wider frequency range, making high-frequency components of the signal more susceptible to LED nonlinear effects. When the PAPR of the input signal is high, the instantaneous peak power of the signal may exceed the linear operating range of the micro-LED, leading to signal distortion, which is particularly significant in high-frequency components. This places higher demands on existing PAPR reduction techniques. Summary of the Invention

[0008] The purpose of this application is to provide a method and apparatus for reducing the peak-to-average power ratio of a micro LED optical communication system in response to the aforementioned technical problems.

[0009] In a first aspect, the present invention provides a method for reducing the peak-to-average power ratio of a micro LED optical communication system, comprising the following steps:

[0010] At the transmitter of the VLC system, the modulation data of the first user and the modulation data of the second user are acquired. The modulation data of the first user and the modulation data of the second user are precoded by the precoding matrix respectively to obtain the precoded output signal of the first user and the precoded output signal of the second user respectively.

[0011] Based on the power allocation factor and the total power of the precoded output signals of the first user and the second user, the precoded output signals of the first user and the second user are combined and calculated to obtain the precoded frequency domain signal.

[0012] Expand the precoded frequency-domain signal into an extended frequency-domain signal with Hermitian symmetry, and perform an inverse fast Fourier transform on the extended frequency-domain signal to obtain a precoded time-domain signal;

[0013] Perform μ-law compression processing on the precoded time-domain signal to obtain a compressed signal, and calculate the peak-to-average power ratio based on the compressed signal.

[0014] Preferably, the order of the precoding matrix is R*N, expressed as:

[0015]

[0016] where PM represents the precoding matrix, and the elements of the precoding matrix are defined as:

[0017]

[0018] where N is the number of subcarriers of the baseband modulated data, Np is the null carrier, 0 < N < N, R = N + Np, m ∈ {0, 1, 2,..., R - 1}, and k ∈ {0, 1, 2,..., N - 1}, j is an imaginary number, P m,k represents the element in the (m - 1)-th row and (k - 1)-th column of the precoding matrix, P m,0 represents the element in the (m - 1)-th row and the 1st column of the precoding matrix, expressed as:

[0019]

[0020] Preferably, perform precoding on the modulated data of the first user and the modulated data of the second user respectively through the precoding matrix to obtain the precoded output signal of the first user and the precoded output signal of the second user respectively, specifically including:

[0021] Y1 = PM * X1;

[0022] Y2 = PM * X2;

[0023] where PM represents the precoding matrix, X1 represents the modulated data of the first user, X2 represents the modulated data of the second user, Y1 represents the precoded output signal of the first user, and Y2 represents the precoded output signal of the second user.

[0024] Preferably, the precoded frequency-domain signal is expressed as:

[0025]

[0026] where S p is the precoded frequency-domain signal, α is the power allocation factor, Y1 represents the precoded output signal of the first user, Y2 represents the precoded output signal of the second user, P totis the total power of Y1 and Y2, S p consists of N subcarriers, expressed as:

[0027] S p =[S0, S1, S2, …, S N-1 T ;

[0028] where, S N-1 represents the Nth subcarrier in the precoded frequency-domain signal;

[0029] The extended signal is expressed as: S HS =[S0, …, S N , …, S 2N-i , …, S 2N-1 T ;

[0030] where, S i represents the (i + 1)th subcarrier in the extended signal, S 2N-K is the complex conjugate of S i .

[0031] Preferably, the precoded time-domain signal is expressed as:

[0032]

[0033] where, Y(n) represents the precoded time-domain signal, S i represents the (i + 1)th subcarrier in the extended signal, N is the number of subcarriers of the baseband modulated data, Np is the null carrier, 0 < N p < N, R = N + Np, n represents the discrete-time sampling point of the precoded time-domain signal.

[0034] Preferably, the compressed signal is expressed as:

[0035]

[0036] where, S [[ID= proposed (n) represents the compressed signal, μ represents the compression control factor, with a range of 0 - 255, v represents the maximum amplitude, sgn(Y(n)) represents the sign function of Y(n);

[0037] The peak-to-average power ratio is expressed as:

[0038]

[0039] where, |S proposed (n) max | 2 represents the peak power of the compressed signal, E|S proposed (n)| 2This represents the average power of the peak signal.

[0040] Secondly, the present invention provides an apparatus for reducing the peak-to-average power ratio of a micro LED optical communication system, comprising:

[0041] The precoding module is configured to acquire modulation data of the first user and modulation data of the second user at the transmitter of the VLC system, and precode the modulation data of the first user and the modulation data of the second user respectively through the precoding matrix to obtain the precoded output signal of the first user and the precoded output signal of the second user respectively.

[0042] The combined calculation module is configured to perform combined calculations on the precoded output signals of the first user and the second user based on the power allocation factor and the total power of the precoded output signals of the first user and the second user, to obtain the precoded frequency domain signal.

[0043] The transformation module is configured to extend the precoded frequency domain signal into an extended frequency domain signal with Hermitian symmetry, and perform an inverse fast Fourier transform on the extended frequency domain signal to obtain the precoded time domain signal.

[0044] The compression module is configured to perform μ-law compression processing on the precoded time-domain signal to obtain a compressed signal, and calculate the peak-to-average power ratio based on the compressed signal.

[0045] Thirdly, the present invention provides an electronic device including one or more processors; and a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any implementation of the first aspect.

[0046] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any of the implementations of the first aspect.

[0047] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in any of the implementations in the first aspect.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The method for reducing the peak-to-average power ratio (PAPR) of micro-LED optical communication systems proposed in this invention effectively reduces the PAPR of micro-LED-based VLC systems by combining the use of precoding matrix and u-law companding. By optimizing the precoding and dynamic range compression of the signal, not only is the PAPR reduced, but the integrity of the signal and the transmission efficiency are also maintained.

[0050] (2) The method for reducing the peak-to-average power ratio (PAPR) of a micro LED optical communication system proposed in this invention reduces the nonlinear distortion of the LED by decreasing PAPR, thereby improving the utilization efficiency of the light source and the overall energy efficiency of the system. This is particularly important for VLC systems that use LEDs as the light source, as the performance of the LEDs directly affects communication quality and energy consumption. Since the technical solution proposed in this invention can be implemented without relying on additional hardware support, it also greatly reduces the cost of system deployment and maintenance.

[0051] (3) The method for reducing the peak-to-average power ratio of a micro LED optical communication system proposed in this invention improves the signal processing efficiency and fault tolerance of the system by reducing PAPR, making the system more stable. It is particularly suitable for deployment in indoor environments with dense user populations and high data demand, making this invention commercially and technically valuable and expected to be widely used in the field of high-speed VLC communication. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a flowchart illustrating a method for reducing the peak-to-average power ratio of a micro LED optical communication system according to an embodiment of this application.

[0054] Figure 2 A system architecture diagram of a method for reducing the peak-to-average power ratio of a micro LED optical communication system according to an embodiment of this application;

[0055] Figure 3 This is a schematic flowchart of the transmitter end of a method for reducing the peak-to-average power ratio of a micro LED optical communication system according to an embodiment of this application.

[0056] Figure 4 This is a schematic flowchart of the receiving end of a method for reducing the peak-to-average power ratio of a micro LED optical communication system according to an embodiment of this application.

[0057] Figure 5Schematic diagram of the device for reducing the peak-to-average power ratio of the micro-LED optical communication system in the embodiments of the present application;

[0058] Figure 6 Schematic diagram of the hardware structure of the electronic device provided by the embodiments of the present invention. Specific embodiments

[0059] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] Figure 1 A method for reducing the peak-to-average power ratio of a micro-LED optical communication system provided by the embodiments of the present application is shown, including the following steps:

[0061] S1. Obtain the modulation data of the first user and the modulation data of the second user at the transmitting end of the VLC system, and perform precoding on the modulation data of the first user and the modulation data of the second user through a precoding matrix respectively to obtain the precoded output signal of the first user and the precoded output signal of the second user.

[0062] In a specific embodiment, the order of the precoding matrix is R*N, expressed as:

[0063]

[0064] Among them, PM represents the precoding matrix, and the elements of the precoding matrix are defined as:

[0065]

[0066] Among them, N is the number of subcarriers of the baseband modulation data, Np is the null carrier, 0 < N p < N, R = N + Np, m ∈ {0, 1, 2,..., R - 1}, and k ∈ {0, 1, 2,..., N - 1}, j is an imaginary number, P m,k represents the element in the (m - 1)-th row and the (k - 1)-th column of the precoding matrix, P m,0 represents the element in the (m - 1)-th row and the 1st column of the precoding matrix, expressed as:

[0067]

[0068] In a specific embodiment, the modulation data of the first user and the modulation data of the second user are precoded by a precoding matrix respectively, and the precoded output signals of the first user and the second user are obtained respectively, which specifically includes:

[0069] Y1 = PM * X1;

[0070] Y2 = PM * X2;

[0071] Where, PM represents the precoding matrix, X1 represents the modulation data of the first user, X2 represents the modulation data of the second user, Y1 represents the precoded output signal of the first user, and Y2 represents the precoded output signal of the second user.

[0072] Specifically, the embodiment of the present application is used for a high-speed VLC system of micro LEDs, and specifically combines precoding and companding techniques. The system architecture is as Figure 2 shown, including a transmitting end and a receiving end. As Figure 3 shown, at the transmitting end, assume that X1 and X2 respectively represent the modulation data of the first user (U1) and the second user (U2). The modulation data of the first user and the second user are respectively preprocessed in the frequency domain by a precoding matrix PM, and thus the precoded output signals of the first user and the second user are obtained. In the precoding matrix PM, Np is the null carrier used to reduce adjacent channel interference, and the value of m is 0 ≤ m < N p , corresponding to the null carrier part, the weight is determined by a sine function; the value of m is N p ≤ m < N p + N, corresponding to the valid data subcarrier part; the value of m is N p + N ≤ m < R - 1, corresponding to the high-frequency part of the carrier, and a cosine function is used to determine. Through the linear transformation of precoding, the peak power of the signal can be effectively reduced.

[0073] S2. Based on the power allocation factor and the total power of the precoded output signal of the first user and the precoded output signal of the second user, the precoded output signal of the first user and the precoded output signal of the second user are combined and calculated to obtain a precoded frequency-domain signal.

[0074] In a specific embodiment, the precoded frequency-domain signal is expressed as:

[0075]

[0076] Where, S p is the precoded frequency-domain signal, α is the power allocation factor, Y1 represents the precoded output signal of the first user, Y2 represents the precoded output signal of the second user, P tot is the total power of Y1 and Y2, and S p is composed of N subcarriers and is expressed as:

[0077] S p = [S0, S1, S2, …, S N-1 T ;

[0078] where, S N-1 represents the Nth sub - carrier in the precoded frequency - domain signal;

[0079] The extended signal is expressed as: S HS = [S0, …, S N , …, S 2N-i , …, S 2N-1 T ;

[0080] where, S i represents the (i + 1)th sub - carrier in the extended signal, S 2N-K is the complex conjugate of S i .

[0081] Specifically, considering the power allocation of different user signals, the precoded output signals of the first user and the second user are combined and calculated. During the calculation process, it is necessary to ensure that the transmission power meets the system limit, so the total power of Y1 and Y2 is used.

[0082] S3, the precoded frequency - domain signal is extended to an extended frequency - domain signal with Hermitian symmetry, and the inverse fast Fourier transform is performed on the extended frequency - domain signal to obtain the precoded time - domain signal.

[0083] In a specific embodiment, the precoded time - domain signal is expressed as:

[0084]

[0085] where, Y(n) represents the precoded time - domain signal, S i represents the (i + 1)th sub - carrier in the extended signal, N is the number of sub - carriers of the base - band modulated data, Np is the null carrier, 0 < N p < N, R = N + Np, n represents the discrete - time sampling point of the precoded time - domain signal.

[0086] Specifically, to meet the requirement of outputting a real - valued time - domain signal in visible - light communication of micro - LEDs, the precoded frequency - domain signal S p is extended to an extended signal S HS with Hermitian symmetry. The extended signal S HS generated by Hermitian - symmetry transformation (HS) is the precoded frequency - domain signal S p ​​Twice the length. To adapt to the unipolar optical signal transmission of micro LEDs, a DC bias (DCO-bias) and clipping are required. Therefore, the extended signal is subjected to an inverse fast Fourier transform (IFFT) to generate a real-valued precoded time-domain signal Y(n), and a DC bias is applied to ensure that the signal is suitable for transmission of micro LED light sources.

[0087] S4 performs μ-law compression on the precoded time-domain signal to obtain a compressed signal, and calculates the peak-to-average power ratio based on the compressed signal.

[0088] In a specific embodiment, the compressed signal is represented as:

[0089]

[0090] Among them, S proposed (n) represents the compressed signal, μ represents the compression control factor, ranging from 0 to 255, v represents the maximum amplitude, and sgn(Y(n)) represents the sign function of Y(n);

[0091] The peak-to-average power ratio is expressed as:

[0092]

[0093] Among them, |S proposed (n) max | 2 E|S represents the peak power of the compressed signal. proposed (n)| 2 This represents the average power of the peak signal.

[0094] Specifically, the precoded time-domain signal Y(n) is subjected to μ-law compression to obtain a compressed signal. The PAPR (Peak-to-Average Power Ratio) of the time-domain signal is related to the ratio of the blocked power to the average power of the compressed signal. μ-law compression is applied to the precoded time-domain signal to further suppress instantaneous power peaks. This nonlinear compression operation effectively reduces PAPR while preserving the signal's phase information. Through signal precoding and amplitude compression, the peak power of the signal is reduced. The compressed signal is emitted through a miniature LED light source to achieve wireless transmission of the optical signal. During transmission, high-frequency components of the signal are appropriately suppressed to mitigate the nonlinear distortion of the miniature LED.

[0095] At the receiving end of a NOMA network, the base station (BS) receives the signal transmitted by each user. The received signal is represented as follows:

[0096]

[0097] Where L represents the total number of users, h(g) is the channel coefficient of the g-th user, and P totThis represents the total power used, and ε is Gaussian white noise with a mean of 0 and a standard deviation of σ, denoted as ε~N(0,δ).

[0098] like Figure 4 As shown, the receiver receives the optical signal transmitted from the transmitter through a photodetector. After converting the optical signal into an electrical signal, it sequentially performs μ-law inverse compression to restore the dynamic range and removes the cyclic prefix to eliminate the empty carrier portion. The decompression formula is as follows:

[0099]

[0100] Among them, S recv (n) represents the received electrical signal, and μ is the compression control factor consistent with that of the transmitter.

[0101] The time-domain signal is then converted to a frequency-domain signal using a Fast Fourier Transform (FFT), and a precoding removal operation is performed on the frequency-domain signal to recover the original modulated signal. This is achieved using the inverse matrix PM. -1 The signal is decoded to recover the independent signal for each user. This decoding process ensures the integrity of the user signal and reduces the impact of multi-user interference.

[0102] In multi-user scenarios, the receiver uses serial interference cancellation (SIC) to decode the signal of each user step by step, and finally restores the data by demodulation, thereby realizing the separation and restoration of multi-user signals.

[0103] The method for reducing the peak-to-average power ratio (P / A ratio) of a micro-LED optical communication system proposed in the embodiments of this application is compared with other methods for reducing P / A ratio in terms of overall complexity. The comparison results are shown in Table 1, where U: number of candidate signals, optimization parameter in SLM; V: number of phase rotation combinations, optimization parameter in PTS; N: number of subcarriers, affecting the complexity of all methods; O(x): complexity representation. It can be seen that the method for reducing the P / A ratio of a micro-LED optical communication system proposed in the embodiments of this application can effectively reduce the system complexity.

[0104] Table 1

[0105]

[0106] Further reference Figure 5 As an implementation of the methods shown in the above figures, this application provides an embodiment of a device for reducing the peak-to-average power ratio of a micro LED optical communication system. This device embodiment is similar to... Figure 1 Corresponding to the method embodiments shown, this device can be specifically applied to various electronic devices.

[0107] This application provides an apparatus for reducing the peak-to-average power ratio of a micro LED optical communication system, comprising:

[0108] Precoding module 1 is configured to acquire modulation data of the first user and modulation data of the second user at the transmitter of the VLC system, and precode the modulation data of the first user and the modulation data of the second user respectively through a precoding matrix to obtain the precoded output signal of the first user and the precoded output signal of the second user respectively.

[0109] The combined calculation module 2 is configured to perform combined calculations on the precoded output signals of the first user and the second user based on the power allocation factor and the total power of the precoded output signals of the first user and the second user, to obtain the precoded frequency domain signal.

[0110] Transformation module 3 is configured to extend the precoded frequency domain signal into an extended frequency domain signal with Hermitian symmetry, and perform an inverse fast Fourier transform on the extended frequency domain signal to obtain the precoded time domain signal.

[0111] Compression module 4 is configured to perform μ-law compression processing on the precoded time-domain signal to obtain a compressed signal, and calculate the peak-to-average power ratio based on the compressed signal.

[0112] Figure 6 This is a schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present invention. For example... Figure 6 As shown, the electronic device of this embodiment includes a processor 601 and a memory 602; wherein the memory 602 is used to store computer execution instructions; and the processor 601 is used to execute the computer execution instructions stored in the memory to implement the various steps performed by the electronic device in the above embodiment. For details, please refer to the relevant descriptions in the foregoing method embodiments.

[0113] Alternatively, the memory 602 can be either standalone or integrated with the processor 601.

[0114] When the memory 602 is set up independently, the electronic device also includes a bus 603 for connecting the memory 602 and the processor 601.

[0115] This invention also provides a computer storage medium storing computer execution instructions, which, when executed by processor 601, implement the above method.

[0116] This invention also provides a computer program product, including a computer program that, when executed by a processor 601, implements the above-described method.

[0117] In the embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, and may be electrical, mechanical, or other forms.

[0118] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to implement the solution of this embodiment according to actual needs.

[0119] Furthermore, the functional modules in the various embodiments of this invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit. The unit formed by the above modules can be implemented in hardware or in the form of hardware plus software functional units.

[0120] The integrated modules described above, implemented as software functional modules, can be stored in a computer-readable storage medium. These software functional modules, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor 601 to execute some steps of the methods of the various embodiments of this application.

[0121] It should be understood that the processor 601 described above can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor, or the processor 601 can be any conventional processor 601. The steps of the method disclosed in this invention can be directly manifested as the hardware processor 601 executing the steps, or as a combination of hardware and software modules within the processor 601 executing the steps.

[0122] The memory 602 may include high-speed RAM memory, and may also include non-volatile memory NVM, such as at least one disk storage device, and may also be a USB flash drive, portable hard drive, read-only memory, disk or optical disc, etc.

[0123] Bus 603 can be an Industry Standard Architecture (ISA), a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 603 can be divided into address bus, data bus, control bus, etc. For ease of illustration, the bus 603 in the accompanying drawings of this application is not limited to only one bus 603 or one type of bus 603.

[0124] The aforementioned storage medium can be implemented from any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The storage medium can be any available medium accessible to general-purpose or special-purpose computers.

[0125] An exemplary storage medium is coupled to a processor 601, enabling the processor 601 to read information from and write information to the storage medium. Alternatively, the storage medium can be an integral part of the processor 601. The processor 601 and the storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor 601 and the storage medium can exist as discrete components in an electronic device or a host device.

[0126] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reducing the peak-to-average power ratio of a micro LED optical communication system, characterized in that, Includes the following steps: At the transmitter of the VLC system, modulation data from the first user and modulation data from the second user are acquired. These modulated data are then precoded using precoding matrices to obtain precoded output signals for the first and second users, respectively. The order of the precoding matrix is... , is represented as: ； Where PM represents the precoding matrix, and the elements of the precoding matrix are defined as: ； in, The number of subcarriers for baseband modulation data. It is an empty carrier. , , ,and j is an imaginary number. This represents the element in the (m-1)th row and (k-1)th column of the precoding matrix. The element in the (m-1)th row and 1st column of the precoding matrix is ​​represented as: ； Based on the power allocation factor and the total power of the precoded output signals of the first user and the second user, the precoded output signals of the first user and the second user are combined and calculated to obtain a precoded frequency domain signal, which is represented as follows: ； in, For precoded frequency domain signals, For power allocation factor, This represents the precoded output signal of the first user. This indicates the precoded output signal of the second user. for and Total power, Depend on It consists of 1 subcarrier, represented as: ； in, This represents the Nth subcarrier in the precoded frequency domain signal; The extended frequency domain signal is represented as: ; in, This represents the (i+1)th subcarrier in the extended frequency domain signal. , for The complex conjugate; The precoded frequency domain signal is extended into an extended frequency domain signal with Hermitian symmetry, and the extended frequency domain signal is subjected to an inverse fast Fourier transform to obtain the precoded time domain signal. The precoded time-domain signal is subjected to μ-law compression to obtain a compressed signal, and the peak-to-average power ratio is calculated based on the compressed signal.

2. The method for reducing the peak-to-average power ratio of a micro LED optical communication system according to claim 1, characterized in that, The modulation data of the first user and the modulation data of the second user are precoded using precoding matrices to obtain the precoded output signals of the first user and the second user, respectively. Specifically, this includes: ； ； Where PM represents the precoding matrix. This represents the modulation data of the first user. This represents the modulation data of the second user. This represents the precoded output signal of the first user. This indicates the precoded output signal of the second user.

3. The method for reducing the peak-to-average power ratio of a micro LED optical communication system according to claim 1, characterized in that, The precoded time-domain signal is represented as follows: ； in, Represents the precoded time-domain signal. This represents the (i+1)th subcarrier in the extended frequency domain signal. The number of subcarriers for baseband modulation data. It is an empty carrier. , , where n represents the discrete-time sampling points of the precoded time-domain signal.

4. The method for reducing the peak-to-average power ratio of a micro LED optical communication system according to claim 1, characterized in that, The compressed signal is represented as: ； in, Indicates a compressed signal. This represents the compression control factor, ranging from 0 to 255. Indicates the maximum amplitude. express The sign function; The peak-to-average power ratio is expressed as: ； in, This indicates the peak power of the compressed signal. This represents the average power of the compressed signal.

5. A device for reducing the peak-to-average power ratio of a micro LED optical communication system, characterized in that, include: The precoding module is configured to acquire modulation data from a first user and modulation data from a second user at the transmitter of a VLC system, and precode the modulation data from the first user and the second user respectively using a precoding matrix to obtain precoded output signals from the first user and the second user, respectively. The order of the precoding matrix is... , is represented as: ； Where PM represents the precoding matrix, and the elements of the precoding matrix are defined as: ； in, The number of subcarriers for baseband modulation data. It is an empty carrier. , , ,and j is an imaginary number. This represents the element in the (m-1)th row and (k-1)th column of the precoding matrix. The element in the (m-1)th row and 1st column of the precoding matrix is ​​represented as: ； The combination calculation module is configured to perform combination calculations on the precoded output signals of the first user and the second user based on the power allocation factor and the total power of the precoded output signals of the first user and the second user, to obtain a precoded frequency domain signal, which is represented as follows: ； in, For precoded frequency domain signals, For power allocation factor, This represents the precoded output signal of the first user. This indicates the precoded output signal of the second user. for and Total power, Depend on It consists of 1 subcarrier, represented as: ； in, This represents the Nth subcarrier in the precoded frequency domain signal; The extended frequency domain signal is represented as: ; in, This represents the (i+1)th subcarrier in the extended frequency domain signal. , for The complex conjugate; The transformation module is configured to extend the precoded frequency domain signal into an extended frequency domain signal with Hermitian symmetry, and perform an inverse fast Fourier transform on the extended frequency domain signal to obtain the precoded time domain signal. The compression module is configured to perform μ-law compression processing on the precoded time-domain signal to obtain a compressed signal, and calculate the peak-to-average power ratio based on the compressed signal.

6. An electronic device, comprising: One or more processors; Storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in any one of claims 1-4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1-4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-4.

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