Method for determining number of intelligent metasurface RIS reflection units in satellite auxiliary communication system

Abstract

The invention provides a method for determining the number of intelligent metasurface RIS reflection units in a satellite auxiliary communication system. The method comprises the following steps: acquiring a large-scale fading characteristic and a small-scale fading characteristic of a channel between a transmitter and each receiver in the satellite auxiliary communication system; obtaining a cumulative distribution function corresponding to the satellite auxiliary communication system and a diagonal phase shift matrix corresponding to the RIS; based on the large-scale fading characteristic, the small-scale fading characteristic, the diagonal phase shift matrix and the transmitting power of the transmitter, acquiring the signal to interference plus noise ratio of each receiver; based on the signal to interference plus noise ratio, the cumulative distribution function and the diagonal phase shift matrix, obtaining a mapping relation between a system outage probability corresponding to the satellite auxiliary communication system and the number of RIS reflection units; and determining the number of target RIS reflection units based on the mapping relation and an outage probability threshold of the satellite auxiliary communication system. According to the scheme of the invention, the number of the RIS reflection units can be accurately configured based on the actual condition of the channel.

Description

Technical Field

[0001] The present application relates to the field of satellite communications, and in particular to a method, device, equipment and storage medium for determining the number of intelligent metasurface RIS reflection units in a satellite-aided communication system. Background Art

[0002] RIS (intelligent metasurface, RIS) technology can enhance signal coverage and quality by intelligently controlling the wireless propagation environment. This technology has gradually become an important means to improve the performance of satellite communication systems.

[0003] In the related art, the determination of the number of RIS reflection units mainly relies on empirical formulas or trial and error methods, and cannot be accurately configured according to the actual communication environment and performance requirements. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] In a first aspect, the present application proposes a method for determining the number of RIS reflection units of an intelligent metasurface in a satellite-aided communication system, the method comprising: obtaining large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in the satellite-aided communication system; wherein the satellite is provided with a RIS and the number of the receivers is at least one; obtaining a cumulative distribution function corresponding to the satellite-aided communication system and a diagonal phase shift matrix corresponding to the RIS; wherein the diagonal transfer matrix is ​​related to the number of RIS reflection units; obtaining a signal-to-interference-to-noise ratio of each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmission power of the transmitter; obtaining a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of the RIS reflection units based on the signal-to-interference-to-noise ratio, the cumulative distribution function and the diagonal phase shift matrix; determining a target number of RIS reflection units based on the mapping relationship and an outage probability threshold of the satellite-aided communication system.

[0006] In one implementation, the channel between the transmitter and each receiver includes a first channel between the transmitter and a satellite, and a second channel between the satellite and each of the receivers. The method of obtaining the large-scale fading characteristics and small-scale fading characteristics of the channel between the transmitter and each receiver in the satellite-assisted communication system includes: obtaining the first large-scale fading characteristics of the first channel and the second large-scale fading characteristics of the second channel based on a free space path loss model; obtaining a first small-scale fading channel vector corresponding to the first channel and an envelope moment of the first channel under Ricean fading channel conditions as the first small-scale fading characteristics; obtaining a second small-scale fading channel vector corresponding to the second channel and an envelope moment of the second channel under Ricean fading channel conditions as the second small-scale fading characteristics.

[0007] In one implementation, the transmit power includes a first transmit power corresponding to a public stream and a second transmit power corresponding to a private stream, and the acquiring a signal to interference and noise ratio of each of the receivers based on the large-scale fading characteristic, the small-scale fading characteristic, the diagonal phase shift matrix, and the transmit power of the transmitter includes: acquiring the first transmit power and the second transmit power based on a preset power division factor and the transmit power; acquiring a first signal amount of a signal transmitted by the transmitter and a second signal amount of a signal received by each of the receivers based on the large-scale fading characteristic, the small-scale fading characteristic, the diagonal phase shift matrix, the first transmit power, and the second transmit power; and acquiring a first signal to interference and noise ratio corresponding to the public stream and a second signal to interference and noise ratio corresponding to the private stream of each of the receivers based on the large-scale fading characteristic, the small-scale fading characteristic, the first signal amount, and the second signal amount.

[0008] In an optional implementation, acquiring a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of the RIS reflection units based on the signal to interference and noise ratio, the cumulative distribution function, and the diagonal phase shift matrix includes: acquiring a system bandwidth of the satellite-aided communication system; acquiring a first information rate corresponding to the public stream of each of the receivers based on the first signal to interference and noise ratio and the system bandwidth; acquiring a second information rate corresponding to the private stream of each of the receivers based on the second signal to interference and noise ratio and the system bandwidth; and acquiring a mapping relationship between the system outage probability and the number of the RIS reflection units based on the first information rate, the second information rate, and the cumulative distribution function.

[0009] Optionally, the obtaining of the mapping relationship between the system outage probability and the number of the RIS reflection units based on the first information rate, the second information rate and the cumulative distribution function includes: obtaining a receiver outage probability expression corresponding to each receiver based on the first rate and the second rate corresponding to each receiver, respectively; and obtaining a mapping relationship between the system outage probability and the number of the RIS reflection units based on the receiver outage probability expression corresponding to each receiver and the cumulative distribution function.

[0010] In a second aspect, the present application proposes a device for determining the number of intelligent metasurface RIS reflection units in a satellite-aided communication system, the device comprising: a first acquisition module, used to obtain large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in the satellite-aided communication system; wherein the satellite is provided with a RIS and the number of the receiver is at least one; a second acquisition module, used to obtain a cumulative distribution function corresponding to the satellite-aided communication system and a diagonal phase shift matrix corresponding to the RIS; wherein the diagonal transfer matrix is ​​related to the number of RIS reflection units; a first processing module, used to obtain a signal-to-interference-to-noise ratio of each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmit power of the transmitter; a second processing module, used to obtain a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of the RIS reflection units based on the signal-to-interference-to-noise ratio, the cumulative distribution function and the diagonal phase shift matrix; a third processing module, used to determine the target number of RIS reflection units based on the mapping relationship and the outage probability threshold of the satellite-aided communication system.

[0011] In one implementation, the channel between the transmitter and each receiver includes a first channel between the transmitter and a satellite, and a second channel between the satellite and each of the receivers. The first acquisition module can be used to: obtain a first large-scale fading characteristic of the first channel and a second large-scale fading characteristic of the second channel based on a free space path loss model; obtain a first small-scale fading channel vector corresponding to the first channel and an envelope moment of the first channel under Ricean fading channel conditions as the first small-scale fading characteristic; obtain a second small-scale fading channel vector corresponding to the second channel and an envelope moment of the second channel under Ricean fading channel conditions as the second small-scale fading characteristic.

[0012] In one implementation, the transmit power includes a first transmit power corresponding to a public stream and a second transmit power corresponding to a private stream, and the first processing module can be used to: obtain the first transmit power and the second transmit power based on a preset power division factor and the transmit power; obtain a first signal amount of a signal transmitted by the transmitter and a second signal amount of a signal received by each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix, the first transmit power, and the second transmit power; and obtain a first signal to noise ratio corresponding to the public stream and a second signal to noise ratio corresponding to the private stream of each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the first signal amount, and the second signal amount.

[0013] In an optional implementation, the second processing module can be used to: obtain the system bandwidth of the satellite-assisted communication system; based on the first signal to interference and noise ratio and the system bandwidth, obtain the first information rate of each receiver corresponding to the public stream; based on the second signal to interference and noise ratio and the system bandwidth, obtain the second information rate of each receiver corresponding to the private stream; based on the first information rate, the second information rate and the cumulative distribution function, obtain the mapping relationship between the system outage probability and the number of the RIS reflection units.

[0014] Optionally, the second processing module can be used to: obtain a receiver interruption probability expression corresponding to each receiver based on the first rate and the second rate corresponding to each receiver, respectively; and obtain a mapping relationship between the system interruption probability and the number of RIS reflection units based on the receiver interruption probability expression corresponding to each receiver and the cumulative distribution function.

[0015] In the third aspect, the present application proposes an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for determining the number of intelligent metasurface RIS reflection units in the satellite-assisted communication system as described in the first aspect.

[0016] In a fourth aspect, the present application proposes a computer-readable storage medium for storing instructions, which, when executed, enables the method described in the first aspect to be implemented.

[0017] In a fifth aspect, the present application proposes a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the method for determining the number of intelligent metasurface RIS reflection units in a satellite-assisted communication system as described in the first aspect.

[0018] The method, device, equipment and storage medium for determining the number of intelligent metasurface RIS reflection units in a satellite-aided communication system provided by the present application can obtain the signal-to-interference-noise ratio of the receiver and the cumulative distribution function of the channel gain based on the large-scale fading characteristics and small-scale fading characteristics of the channel between the receiver and the transmitter, thereby obtaining the interruption probability corresponding to different numbers of RIS reflection units according to the cumulative distribution function of the channel gain and the signal-to-interference-noise ratio, thereby configuring the number of RIS reflection units according to a preset terminal probability threshold. The number of RIS reflection units can be accurately configured based on the actual channel environment and performance requirements.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0021] Figure 1 This is an application scenario diagram for determining the number of RIS reflection units in a satellite-aided communication system provided by an embodiment of the present application;

[0022] Figure 2 It is a flow chart of a method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application;

[0023] Figure 3 It is a flow chart of another method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application;

[0024] Figure 4 It is a flowchart of another method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application;

[0025] Figure 5 is a flow chart for calculating the number of RIS reflection units provided by an embodiment of the present application;

[0026] Figure 6 It is a structural schematic diagram of a device for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application;

[0027] Figure 7 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] The following describes a method and device for determining the number of RIS (Reconfigurable Intelligent Surface) in a satellite-assisted communication system according to an embodiment of the present application with reference to the accompanying drawings.

[0030] See also Figure 1 , Figure 1 1 is an application scenario diagram of determining the number of RIS reflection units in a satellite-aided communication system provided by an embodiment of the present application. Figure 1 As shown, the application scenario includes: Tx (Transmitter), RIS-empowered satellites (RIS-enabled satellites) and Rx (Receivers). Among them, there is at least one Rx, and at least one reflection unit is configured in the RIS-empowered satellites.

[0031] In the related art, the number of RIS reflection units in a RIS-enabled satellite is often configured through empirical formulas or trial and error methods.

[0032] In response to the above technical problems, the present application proposes the following technical concept: according to the channel characteristics corresponding to the first communication link between the transmitter and the RIS-enabled satellite, and the channel characteristics corresponding to the second communication link between the RIS-enabled satellite and the receiver, the signal-to-interference-and-noise ratio of the receiver is obtained, and based on the signal-to-interference-and-noise ratio of the receiver, a mapping relationship between the satellite-aided communication system and the number of RIS reflection units is established, so as to configure the number of RIS reflection units of the RIS-enabled satellite based on the above mapping relationship and communication requirements.

[0033] See also Figure 2 , Figure 2 FIG. 1 is a flow chart of a method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application. Figure 2 As shown, the method may include but is not limited to the following steps:

[0034] Step S201: obtaining large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in a satellite-aided communication system.

[0035] Among them, there is at least one receiver.

[0036] It can be understood that the channel between the transmitter and each receiver in the satellite-assisted communication system includes the channel between the transmitter and the satellite, and the channel between the satellite and the receiver.

[0037] Exemplarily, large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and a satellite in a satellite-aided communication system, as well as large-scale fading characteristics and small-scale fading characteristics of a channel between a satellite and each receiver are obtained.

[0038] Step S202: Obtain the cumulative distribution function corresponding to the satellite-aided communication system and the diagonal phase shift matrix corresponding to the RIS.

[0039] The above diagonal transfer matrix is ​​related to the number of RIS reflection units.

[0040] In the embodiments of the present application, the terms "diagonal phase shift matrix" and "diagonal phase offset matrix" can be replaced with each other.

[0041] Exemplarily, assuming that the channels of the Tx-RIS and RIS-Rx links are independent and identically distributed, the cumulative distribution function of the channel gain in the satellite-aided communication system can be expressed as follows:

[0042]

[0043] Among them, I v (·) represents the first kind of modified Bessel function, Q v (·,·) represents Malkum’s Q function, γ(·,·) represents the incomplete gamma function, Γ(·) represents the gamma function, and L is the number of RIS reflection units, h l is the small-scale fading characteristic vector of the link between the receiver and each RIS, g l,k is the small-scale fading vector corresponding to the link between each RIS unit and each receiver, v=E[|h l |]E[|g l,k |], E[] represents the expected value.

[0044] Step S203: based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmit power of the transmitter, the signal-to-interference-and-noise ratio of each receiver is obtained.

[0045] Exemplarily, based on large-scale fading characteristics and small-scale fading characteristics, the received signal power of the signal received by the receiver after the signal sent by the transmitter with the transmit power has undergone path loss and attenuation is obtained, thereby calculating the signal-to-interference-and-noise ratio of the receiver based on the received signal power, the transmit signal power, and the interference and noise levels.

[0046] For example, if the RIS is composed of L reflective elements, the RIS diagonal phase shift matrix can be expressed as follows:

[0047]

[0048] Where Φ is the diagonal phase shift matrix, θ l is the phase offset of the lth reflection unit in RIS, and C represents the dimension of the complex domain.

[0049] Step S204: Based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix, a mapping relationship between the system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units is obtained.

[0050] Exemplarily, the signal to interference and noise ratio of the receiver is substituted into the cumulative distribution function, and the outage probability under different numbers of RIS units is calculated, so as to obtain the mapping relationship between the system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units.

[0051] Step S205: Determine the number of target RIS reflection units based on the mapping relationship and the interruption probability threshold of the satellite-aided communication system.

[0052] For example, assuming that the interruption probability tolerance of the satellite-aided communication system is ξ, the number of RIS reflection units can be expressed as follows:

[0053]

[0054] Where L is the number of RIS reflector units, P o is the interruption probability of the satellite-aided communication system, ξ is the interruption probability tolerance of the satellite-aided communication system, According to P o =ξFind the inverse function of L.

[0055] By implementing the embodiments of the present application, the signal to interference noise ratio of the receiver and the cumulative distribution function of the channel gain can be obtained based on the large-scale fading characteristics and small-scale fading characteristics of the channel between the receiver and the transmitter, and the interruption probability corresponding to different numbers of RIS reflection units can be obtained according to the cumulative distribution function of the channel gain in combination with the signal to interference noise ratio, so as to configure the number of RIS reflection units according to the preset terminal probability threshold. The number of RIS reflection units can be accurately configured based on the actual channel environment and performance requirements.

[0056] In some embodiments, the channel between the transmitter and each receiver includes a first channel between the transmitter and the satellite, and a second channel between the satellite and each receiver. The large-scale fading characteristics and small-scale fading characteristics of the channel between the transmitter and each receiver in the satellite-aided communication system can be obtained based on the wireless channel model. As an example, see Figure 3 , Figure 3 FIG. 1 is a flow chart of another method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application. Figure 3 As shown, the method may include but is not limited to the following steps:

[0057] Step S301: based on a free space path loss model, obtaining a first large-scale fading characteristic of a first channel and a second large-scale fading characteristic of a second channel.

[0058] Exemplarily, the first large-scale fading characteristic may be expressed as follows:

[0059]

[0060] Among them, d t is the distance of the communication link between the transmitter and the RIS, G T is the transmitter antenna gain, c is the speed of light, f c is the carrier frequency, is the path loss exponent.

[0061] Exemplarily, the second largest scale fading characteristic can be expressed as follows:

[0062]

[0063] Among them, d r is the distance of the communication link between RIS and the receiver, G R is the antenna gain of the receiver, c is the speed of light, f c is the carrier frequency, is the path loss exponent.

[0064] Step S302: Obtain a first small-scale fading channel vector corresponding to the first channel and an envelope moment of the first channel under a Ricean fading channel condition as a first small-scale fading characteristic.

[0065] For example, the small-scale fading channel from the transmitter to the Lth reflection unit in the RIS is represented by h l Indicates that the first small-scale fading channel vector can be expressed as follows:

[0066] H=(h1,h2,...,h L ) T ∈C L×1

[0067] Where H is the first small-scale fading channel vector, L is a positive integer, and the maximum value of L is the same as the maximum number of RIS. Represents the dimension of the complex field.

[0068] Exemplarily, the above envelope moment can be expressed as follows:

[0069]

[0070] where 2F1(·,·,·,·) is the Gaussian hypergeometric function, Γ(·) is the gamma function, ∈ is the order of the moment, 2a is the average power of the scattered component, Ω is the average power of the line-of-sight (LOS) component, and m is the Nakagami parameter.

[0071] Step S303: Obtain a second small-scale fading channel vector corresponding to the second channel and an envelope moment of the second channel under a Ricean fading channel condition as a second small-scale fading characteristic.

[0072] For example, the small-scale fading channel from the lth RIS to the kth receiver is represented by g l,k Indicates that the second small-scale fading channel vector can be expressed as follows:

[0073] G=(g 1,k ,g 2,k ,...,g L,k )∈C 1×L

[0074] Wherein, G is the second smallest scale fading channel vector, L is a positive integer, and the maximum value of L is the same as the maximum number of RIS.

[0075] Step S304: Obtain the cumulative distribution function corresponding to the satellite-aided communication system and the diagonal phase shift matrix corresponding to the RIS.

[0076] In the embodiments of the present application, step S304 can be implemented by any of the methods in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0077] Step S305: based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmit power of the transmitter, the signal-to-interference-and-noise ratio of each receiver is obtained.

[0078] In the embodiments of the present application, step S305 can be implemented in any of the ways in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0079] Step S306: Based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix, a mapping relationship between the system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units is obtained.

[0080] In the embodiments of the present application, step S306 can be implemented in any of the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0081] Step S307: Determine the number of target RIS reflection units based on the mapping relationship and the interruption probability threshold of the satellite-aided communication system.

[0082] In the embodiments of the present application, step S307 can be implemented by any of the methods in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0083] By implementing the embodiments of the present application, the large-scale fading characteristics and small-scale fading characteristics of the channel between the transmitter and each receiver in the satellite-aided communication system can be obtained based on the corresponding channel model, so as to determine the target number of RIS reflection units based on the large-scale fading characteristics and the small-scale fading characteristics, and the number of RIS reflection units can be accurately configured based on the actual channel environment and performance requirements.

[0084] In some embodiments, the transmitter in the satellite-assisted communication system adopts RSMA (Rate-Splitting Multiple Access) technology, in which the data received by each receiver is divided into two parts: a public part and a private part. The public parts of all receivers are combined and encoded into a single public data stream using a standard codebook, while the private part of each receiver is encoded into a separate private data stream for each receiver. At this time, the transmission power of the transmitter includes a first transmission power corresponding to the public stream and a second transmission power corresponding to the private stream. Please refer to Figure 4 , Figure 4 FIG. 1 is a flow chart of another method for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application. Figure 4 As shown, the method may include but is not limited to the following steps:

[0085] Step S401: obtaining large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in a satellite-assisted communication system.

[0086] In the embodiments of the present application, step S401 can be implemented by any of the methods in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0087] Step S402: Obtain the cumulative distribution function corresponding to the satellite-aided communication system and the diagonal phase shift matrix corresponding to the RIS.

[0088] In the embodiments of the present application, step S402 can be implemented by any of the methods in the embodiments of the present application, and the embodiments of the present application do not limit this and will not be described in detail.

[0089] Step S403: Obtain the spreading gain corresponding to the satellite-aided communication system.

[0090] Step S404: Based on the preset power division factor and the transmit power, a first transmit power and a second transmit power are acquired.

[0091] For example, in RSMA, let the total transmission power of the transmitter be P t , P c is the transmission power of the public data stream, P p,k is the transmission power of the private data stream corresponding to the kth receiver, k is a positive integer, and uniform power distribution is adopted between private data streams, then P c and P p,k Satisfies the following formula:

[0092] P c =αP t

[0093]

[0094] Where α is the power division factor.

[0095] Step S405: Based on the first large-scale fading characteristic, the second large-scale fading characteristic, the first small-scale fading characteristic, the second small-scale fading characteristic, the spreading gain, the diagonal phase shift matrix, the first transmit power, and the second transmit power, obtain a first signal to interference plus noise ratio of each receiver in the public stream and a second signal to interference plus noise ratio of each receiver in the private stream.

[0096] Exemplarily, the first signal quantity of the signal transmitted by the transmitter can be expressed as follows:

[0097]

[0098] Among them, x is the first semaphore, P c is the transmission power of the public data stream, s c is the public data stream, P p,k is the transmission power of the private data stream corresponding to the Kth receiver, s p,k is the private data stream corresponding to the kth receiver.

[0099] The amount of signal received by each receiver can be expressed as follows:

[0100]

[0101] Among them, y k is the second signal quantity of the signal received by the kth receiver, is the first large-scale fading channel characteristic between the transmitter and RIS, is the second largest scale fading channel characteristic between RIS and the kth receiver, G is the first small scale fading channel vector, Φ is the diagonal phase shift matrix, H is the second small scale fading channel vector, g s is the spreading gain, N0 is the variance σ 2 Additive white Gaussian noise.

[0102] The first signal to interference and noise ratio can be expressed as follows:

[0103]

[0104] Among them, SINR c,k is the signal-to-interference-noise ratio of the public data stream corresponding to the kth receiver,

[0105] The second signal to interference and noise ratio can be expressed as follows:

[0106]

[0107] Among them, SINR p,k is the signal-to-interference-and-noise ratio of the private data stream corresponding to the kth receiver.

[0108] Step S406: Based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix, a mapping relationship between the system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units is obtained.

[0109] In an optional implementation, the obtaining of the mapping relationship between the system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units based on the signal-to-interference-noise ratio, the cumulative distribution function and the diagonal phase shift matrix may include the following steps:

[0110] A1: Obtain the system bandwidth of the satellite-aided communication system.

[0111] A2: Based on the first signal to interference and noise ratio and the system bandwidth, obtain a first information rate of a public stream corresponding to each receiver.

[0112] Exemplarily, the first information rate may be expressed as follows:

[0113] γ c,k =B log(1+SINR c,k )

[0114] Wherein, B is the available bandwidth of the satellite-aided communication system.

[0115] A3: Based on the second signal to interference and noise ratio and the system bandwidth, obtain a second information rate of the private stream corresponding to each receiver.

[0116] Exemplarily, the second information rate may be expressed as follows:

[0117] γ p,k =B log(1+SINR p,k )

[0118] A4: Based on the first information rate, the second information rate, and the cumulative distribution function, a mapping relationship between the system outage probability and the number of RIS reflector units is obtained.

[0119] Exemplarily, based on the first information rate and the second information rate, the relationship expression between the outage probability and the information rate requirement of each receiver is obtained, and then the mapping relationship expression between the system outage probability and the number of RIS reflection units is obtained based on the above expression and the cumulative distribution function.

[0120] Optionally, acquiring a mapping relationship between a system outage probability and a number of RIS reflector units based on the first information rate, the second information rate, and the cumulative distribution function may include the following steps:

[0121] B1: Based on the first rate and the second rate corresponding to each receiver, obtain the receiver outage probability expression corresponding to each receiver.

[0122] Exemplarily, the outage probability of the kth receiver may be expressed as follows:

[0123]

[0124] Among them, R c,k is the rate requirement threshold of the public data flow corresponding to the kth receiver, R p,k is the rate requirement threshold of the private data stream corresponding to the kth receiver, and

[0125] B2: Based on the receiver outage probability expression and cumulative distribution function corresponding to each receiver, the mapping relationship between the system outage probability and the number of RIS reflector units is obtained.

[0126] Exemplarily, the outage probability of the satellite-aided communication system can be expressed as follows:

[0127]

[0128] Step S407: Determine the number of target RIS reflection units based on the mapping relationship and the interruption probability threshold of the satellite-aided communication system.

[0129] By implementing the embodiments of the present application, the signal to interference noise ratio of the receiver and the cumulative distribution function of the channel gain can be obtained based on the large-scale fading characteristics and small-scale fading characteristics of the channel between the receiver and the transmitter, and the interruption probability corresponding to different numbers of RIS reflection units can be obtained according to the cumulative distribution function of the channel gain in combination with the signal to interference noise ratio, so as to configure the number of RIS reflection units according to the preset terminal probability threshold. The number of RIS reflection units can be accurately configured based on the actual channel environment and performance requirements.

[0130] See also Figure 5 , Figure 5 ] is a flow chart of calculating the number of RIS reflection units provided by an embodiment of the present application. Figure 5 As shown, the quantitative channel statistical characteristics (e.g., multipath effect characteristics, noise power, etc.) of the channel between the transmitter and the receiver in the satellite-aided communication system can be obtained. Then, based on the channel gain, the signal-to-interference-to-noise ratio of the receiver is obtained, and then the interruption probability expression of the system is obtained. Based on the interruption probability expression, the number of RIS reflection units to ensure communication reliability is calculated by combining the channel bandwidth, data transmission requirements and the preset interruption tolerance.

[0131] See also Figure 6 , Figure 6 1 is a schematic diagram of the structure of a device for determining the number of RIS reflection units in a satellite-aided communication system provided in an embodiment of the present application. Figure 6 As shown, the device 600 includes: a first acquisition module 601, used to acquire large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in a satellite-aided communication system; wherein the satellite is provided with a RIS, and there is at least one receiver; a second acquisition module 602, used to acquire a cumulative distribution function corresponding to the satellite-aided communication system and a diagonal phase shift matrix corresponding to the RIS; wherein the diagonal transfer matrix is ​​related to the number of RIS reflection units; a first processing module 603, used to acquire a signal-to-interference-to-noise ratio of each receiver based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmission power of the transmitter; a second processing module 604, used to acquire a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units based on the signal-to-interference-to-noise ratio, the cumulative distribution function and the diagonal phase shift matrix; and a third processing module 605, used to determine the target number of RIS reflection units based on the mapping relationship and an outage probability threshold of the satellite-aided communication system.

[0132] In one implementation, the channel between the transmitter and each receiver includes a first channel between the transmitter and the satellite, and a second channel between the satellite and each receiver. The first acquisition module 601 can be used to: obtain a first large-scale fading characteristic of the first channel and a second large-scale fading characteristic of the second channel based on a free space path loss model; obtain a first small-scale fading channel vector corresponding to the first channel and an envelope moment of the first channel under Ricean fading channel conditions as the first small-scale fading characteristic; obtain a second small-scale fading channel vector corresponding to the second channel and an envelope moment of the second channel under Ricean fading channel conditions as the second small-scale fading characteristic.

[0133] In one implementation, the transmit power includes a first transmit power corresponding to a public stream and a second transmit power corresponding to a private stream. The first processing module 602 can be used to: obtain a spreading gain corresponding to the satellite-assisted communication system; obtain the first transmit power and the second transmit power based on a preset power division factor and the transmit power; and obtain a first signal to interference and noise ratio of each receiver in the public stream and a second signal to interference and noise ratio in the private stream based on the first large-scale fading characteristic, the second large-scale fading characteristic, the first small-scale fading characteristic, the second small-scale fading characteristic, the spreading gain, the diagonal phase shift matrix, the first transmit power, and the second transmit power.

[0134] In an optional implementation, the second processing module 604 can be used to: obtain the system bandwidth of the satellite-assisted communication system; based on the first signal to interference and noise ratio and the system bandwidth, obtain the first information rate of the public stream corresponding to each receiver; based on the second signal to interference and noise ratio and the system bandwidth, obtain the second information rate of the private stream corresponding to each receiver; based on the first information rate, the second information rate and the cumulative distribution function, obtain the mapping relationship between the system interruption probability and the number of RIS reflection units.

[0135] Optionally, the second processing module 604 can be used to: obtain a receiver outage probability expression corresponding to each receiver based on the first rate and the second rate corresponding to each receiver, respectively; and obtain a mapping relationship between the system outage probability and the number of RIS reflection units based on the receiver outage probability expression and the cumulative distribution function corresponding to each receiver.

[0136] Through the device of the embodiment of the present application, the signal to interference noise ratio of the receiver and the cumulative distribution function of the channel gain can be obtained based on the large-scale fading characteristics and small-scale fading characteristics of the channel between the receiver and the transmitter, so as to obtain the interruption probability corresponding to different numbers of RIS reflection units according to the cumulative distribution function of the channel gain and the signal to interference noise ratio, so as to configure the number of RIS reflection units according to the preset terminal probability threshold. The number of RIS reflection units can be accurately configured based on the actual channel environment and performance requirements.

[0137] It should be noted that the above explanation of the embodiment of the method for determining the number of RIS reflection units in a satellite-aided communication system is also applicable to the device for determining the number of RIS reflection units in a satellite-aided communication system in this embodiment, and will not be repeated here.

[0138] In order to implement the above embodiment, the present application also proposes an electronic device. Figure 7 , Figure 7 Schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 7 As shown, the electronic device 700 includes: a processor 701, and a memory 702 communicatively connected to the processor 701; the memory 702 stores computer-executable instructions; the processor 701 executes the computer-executable instructions stored in the memory to implement the method provided in the aforementioned embodiment.

[0139] In order to implement the above embodiments, the present application also proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0140] In order to implement the above embodiments, the present application also proposes a computer program product, including a computer program, which implements the methods provided by the above embodiments when executed by a processor.

[0141] In the description of this application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0142] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0143] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0144] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0145] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0146] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0147] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0148] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0149] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for determining the number of intelligent metasurface RIS reflector units in a satellite-aided communication system, characterized in that: include: Acquiring large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in a satellite-aided communication system; wherein the satellite is provided with a RIS and the number of the receiver is at least one; Acquire a cumulative distribution function corresponding to the satellite-aided communication system and a diagonal phase shift matrix corresponding to the RIS; wherein the diagonal transfer matrix is ​​related to the number of RIS reflection units; Acquire a signal to interference and noise ratio of each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix, and the transmit power of the transmitter; Based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix, obtaining a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of the RIS reflection units; Based on the mapping relationship and the interruption probability threshold of the satellite-aided communication system, the target RIS reflection unit quantity is determined.

2. The method according to claim 1, characterized in that The channel between the transmitter and each receiver includes a first channel between the transmitter and a satellite, and a second channel between the satellite and each receiver. The acquiring of large-scale fading characteristics and small-scale fading characteristics of the channel between the transmitter and each receiver in the satellite-aided communication system includes: Based on a free space path loss model, obtaining a first large-scale fading characteristic of the first channel and a second large-scale fading characteristic of the second channel; Acquire a first small-scale fading channel vector corresponding to the first channel and an envelope moment of the first channel under a Ricean fading channel condition as the first small-scale fading characteristic; A second small-scale fading channel vector corresponding to the second channel and an envelope moment of the second channel under Ricean fading channel conditions are obtained as the second small-scale fading characteristics.

3. The method according to claim 1, characterized in that The transmit power includes a first transmit power corresponding to a public stream and a second transmit power corresponding to a private stream, and the acquiring a signal to interference noise ratio of each receiver based on the large-scale fading characteristic, the small-scale fading characteristic, the diagonal phase shift matrix, and the transmit power of the transmitter includes: Obtaining a spreading gain corresponding to the satellite-aided communication system; Based on a preset power division factor and the transmit power, acquiring the first transmit power and the second transmit power; Based on the first large-scale fading characteristic, the second large-scale fading characteristic, the first small-scale fading characteristic, the second small-scale fading characteristic, the spreading gain, the diagonal phase shift matrix, the first transmit power, and the second transmit power, a first signal to interference plus noise ratio of each receiver in the public stream and a second signal to interference plus noise ratio in the private stream are obtained.

4. The method according to claim 3, characterized in that The acquiring, based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix, a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of the RIS reflection units comprises: Acquiring a system bandwidth of the satellite-aided communication system; Based on the first signal to interference and noise ratio and the system bandwidth, acquiring a first information rate corresponding to the public flow of each of the receivers; Based on the second signal to interference and noise ratio and the system bandwidth, acquiring a second information rate corresponding to the private stream of each of the receivers; Based on the first information rate, the second information rate and the cumulative distribution function, a mapping relationship between the system outage probability and the number of the RIS reflection units is obtained.

5. The method according to claim 4, characterized in that The acquiring, based on the first information rate, the second information rate, and the cumulative distribution function, a mapping relationship between the system outage probability and the number of the RIS reflector units includes: Based on the first rate and the second rate corresponding to each of the receivers, respectively, obtaining a receiver outage probability expression corresponding to each of the receivers; Based on the receiver outage probability expression corresponding to each of the receivers and the cumulative distribution function, a mapping relationship between the system outage probability and the number of the RIS reflection units is obtained.

6. A method for determining the number of intelligent metasurface RIS reflector units in a satellite-aided communication system, characterized in that: include: A first acquisition module is used to acquire large-scale fading characteristics and small-scale fading characteristics of a channel between a transmitter and each receiver in a satellite-aided communication system; wherein the satellite is provided with a RIS and the number of the receiver is at least one; A second acquisition module is used to acquire a cumulative distribution function corresponding to the satellite-aided communication system and a diagonal phase shift matrix corresponding to the RIS; wherein the diagonal transfer matrix is ​​related to the number of RIS reflection units; A first processing module, configured to obtain a signal to interference noise ratio of each of the receivers based on the large-scale fading characteristics, the small-scale fading characteristics, the diagonal phase shift matrix and the transmit power of the transmitter; A second processing module is used to obtain a mapping relationship between a system outage probability corresponding to the satellite-aided communication system and the number of RIS reflection units based on the signal to interference noise ratio, the cumulative distribution function and the diagonal phase shift matrix; The third processing module is used to determine the number of target RIS reflection units based on the mapping relationship and the interruption probability threshold of the satellite-assisted communication system.

7. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method according to any one of claims 1 to 5.

9. A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the computer program implements the steps of the method according to any one of claims 1 to 5.

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