CN116318312A

CN116318312A - Communication strategy selection method and device, electronic equipment and storage medium

Info

Publication number: CN116318312A
Application number: CN202211103618.1A
Authority: CN
Inventors: 郑凤; 倪斌
Original assignee: Nanjing Shangtai Electronic Engineering Co ltd
Current assignee: Nanjing Shangtai Electronic Engineering Co ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-06-23

Abstract

The application provides a communication policy selection method, a device, electronic equipment and a storage medium. The method comprises the following steps: acquiring transmitting end antenna array characteristic information, transmitting end position information, receiving end antenna array characteristic information, receiving end position information, channel characteristic information and system working wavelength; according to the information, determining a first communication strategy for realizing communication through the reconfigurable intelligent surface, determining a second communication strategy for realizing communication through the half-duplex decoding forwarding relay, and determining a third communication strategy for jointly realizing communication through the reconfigurable intelligent surface and the half-duplex decoding forwarding relay; calculating a first reachable rate of the first communication strategy, a second reachable rate of the second communication strategy and a third reachable rate of the third communication strategy; determining a target maximum rate according to the first reachable rate, the second reachable rate and the third reachable rate, and determining a communication strategy corresponding to the target maximum rate as a target communication strategy; the communication element is deployed according to the target communication policy.

Description

Communication strategy selection method and device, electronic equipment and storage medium

Technical Field

The present disclosure relates to the field of wireless communications technologies, and in particular, to a communication policy selection method, a device, an electronic device, and a storage medium.

Background

With the development of mobile communication technology, the target network capacity of the wireless network is greatly improved, which puts higher demands on the transmission capability of the wireless network. In addition to enhancing the capabilities of the base station and the terminal, the related art proposes to utilize the reconfigurable intelligent surface to remodel the wireless channel, thereby improving the shaping capability of the transmission signal and further improving the signal transmission capability. However, the performance of the communication system varies according to the channel characteristics, and the use of reconfigurable intelligent surface-assisted communication is not always an optimal solution for different communication systems. According to experimental data, the auxiliary communication of the half-duplex decoding forwarding repeater can also greatly improve the signal transmission capacity. How to select the best auxiliary communication element according to the communication system performance remains a problem to be solved.

Disclosure of Invention

In view of this, an object of the present application is to propose a communication policy selection method.

Based on the above objects, the present application provides a communication policy selection method. The method comprises the following steps:

Acquiring transmitting end antenna array characteristic information, transmitting end position information, receiving end antenna array characteristic information, receiving end position information, channel characteristic information and system working wavelength;

according to the characteristic information of the antenna array of the transmitting end and the position information of the transmitting end, the characteristic information of the antenna array of the receiving end and the position information of the receiving end, the channel characteristic information and the working wavelength of the system, a first communication strategy for realizing communication through a reconfigurable intelligent surface, a second communication strategy for realizing communication through a half-duplex decoding forwarding relay and a third communication strategy for jointly realizing communication through the reconfigurable intelligent surface and the half-duplex decoding forwarding relay are determined;

calculating a first reachable rate of the first communication strategy, a second reachable rate of the second communication strategy and a third reachable rate of the third communication strategy;

determining a target maximum rate according to the first reachable rate, the second reachable rate and the third reachable rate, and determining a communication strategy corresponding to the target maximum rate as a target communication strategy;

and deploying the communication element according to the target communication strategy.

Optionally, calculating a first achievable rate of the first communication policy includes:

determining position information of the reconfigurable intelligent surface, reflection unit array characteristic information of the reconfigurable intelligent surface and a signal reflection matrix of the reconfigurable intelligent surface according to the first communication strategy;

calculating a channel matrix of a first indirect link according to the transmitting end antenna array characteristic information, the transmitting end position information, the receiving end antenna array characteristic information, the receiving end position information, the position information of the reconfigurable intelligent surface, the reflecting unit array characteristic information of the reconfigurable intelligent surface and the signal reflection matrix of the reconfigurable intelligent surface, and the channel characteristic information and the system working wavelength;

obtaining the maximum average transmitting power and the preset noise power of a transmitting end;

obtaining a transmitting signal covariance matrix according to the maximum average transmitting power and the characteristic information of the transmitting end antenna array;

calculating a first reachable rate according to a first direct link channel matrix, a channel matrix of the first indirect link, the transmitting signal covariance matrix and the noise power; the first direct link channel matrix is obtained according to the transmitting end antenna array characteristic information and the transmitting end position information, the receiving end antenna array characteristic information and the receiving end position information, and the channel characteristic information and the system working wavelength.

Optionally, the method further comprises:

according to the first direct link channel matrix, the first indirect link channel matrix, the transmitting signal covariance matrix and the noise power, performing iterative computation to obtain a plurality of first candidate reachable rates until a converged first candidate reachable rate is obtained or a preset iteration number is reached;

taking the largest of the plurality of first candidate achievable rates as the first achievable rate;

wherein, the first candidate reachable rate is obtained by any iterative calculation, which comprises the following steps:

optimizing the emission signal covariance matrix and the signal reflection matrix of the reconfigurable intelligent surface to obtain an optimized emission signal covariance matrix and an optimized signal reflection matrix;

and calculating to obtain a first candidate reachable rate according to the optimized emission signal covariance matrix and the signal reflection matrix of the optimized reconfigurable intelligent surface.

Optionally, calculating a second achievable rate of the second communication policy includes:

determining the position information of the half-duplex decoding forwarding relay and the antenna array characteristic information of the half-duplex decoding forwarding relay according to the second communication strategy;

according to the characteristic information of the antenna array of the transmitting end and the position information of the transmitting end, the position information of the half-duplex decoding forwarding relay and the characteristic information of the antenna array of the half-duplex decoding forwarding relay, the channel characteristic information and the working wavelength of the system, a second direct link channel matrix between the transmitting end and the half-duplex decoding forwarding relay is calculated;

calculating a first relay reachable rate according to the second direct link channel matrix, the transmitting signal covariance matrix and the noise power;

according to the antenna array characteristic information of the receiving end and the position information of the receiving end, the position information of the half-duplex decoding forwarding relay and the antenna array characteristic information of the half-duplex decoding forwarding relay, the channel characteristic information and the system working wavelength, a third direct link channel matrix between the receiving end and the half-duplex decoding forwarding relay is calculated;

calculating to obtain the reachable rate of the first receiving end according to the first direct link channel matrix, the third direct link channel matrix, the transmitting signal covariance matrix and the noise power; the first direct link channel matrix is obtained according to the transmitting end antenna array characteristic information and the transmitting end position information, the receiving end antenna array characteristic information and the receiving end position information, and the channel characteristic information and the system working wavelength.

Optionally, the method further comprises:

according to the second direct link channel matrix, the transmitting signal covariance matrix and the noise power, performing iterative computation to obtain a plurality of second candidate reachable rates until a converged second candidate reachable rate is obtained or a preset iterative number is reached;

taking the largest of the plurality of second candidate achievable rates as the first relay achievable rate;

according to the first direct link channel matrix, the third direct link channel matrix, the transmitting signal covariance matrix and the noise power, performing iterative computation to obtain a plurality of third candidate reachable rates until a converged third candidate reachable rate is obtained or a preset iteration number is reached;

taking the largest of the plurality of third candidate reachable rates as the reachable rate of the first receiving end;

wherein, the second candidate reachable rate is obtained by any iterative calculation, which comprises the following steps:

optimizing the covariance matrix of the transmission signal to obtain an optimized covariance matrix of the transmission signal;

calculating to obtain a second candidate reachable rate according to the covariance matrix of the optimized transmitting signal;

wherein, the third candidate reachable rate is obtained by any iterative calculation, which comprises the following steps:

and calculating to obtain a third candidate reachable rate according to the covariance matrix of the optimized transmitting signal.

Optionally, calculating a third achievable rate of the third communication policy includes:

determining antenna array characteristic information of the half-duplex decoding forwarding relay, position information of the reconfigurable intelligent surface, reflection unit array characteristic information of the reconfigurable intelligent surface and a signal reflection matrix of the reconfigurable intelligent surface according to the third communication strategy;

according to the antenna array characteristic information of the transmitting end and the position information of the transmitting end, the antenna array characteristic information of the half-duplex decoding forwarding relay and the position information of the half-duplex decoding forwarding relay, the channel characteristic information and the system working wavelength calculate a fourth direct link channel matrix between the transmitting end and the half-duplex decoding forwarding relay; according to the antenna array characteristic information of the transmitting end and the position information of the transmitting end, the position information of the reconfigurable intelligent surface and the reflection unit array characteristic information of the reconfigurable intelligent surface, the signal reflection matrix of the reconfigurable intelligent surface, the antenna array characteristic information of the half-duplex decoding forwarding relay and the position information of the half-duplex decoding forwarding relay, the channel characteristic information and the system working wavelength, a second indirect link channel matrix between the transmitting end and the half-duplex decoding forwarding relay is calculated;

calculating a second relay reachable rate according to the fourth direct link channel matrix, the channel matrix of the second indirect link, the transmitting signal covariance matrix and the noise power;

according to the antenna array characteristic information of the receiving end and the position information of the receiving end, the antenna array characteristic information of the half-duplex decoding forwarding relay and the position information of the half-duplex decoding forwarding relay, the channel characteristic information and the system working wavelength calculate a fifth direct link channel matrix between the receiving end and the half-duplex decoding forwarding relay; according to the antenna array characteristic information of the receiving end, the position information of the reconfigurable intelligent surface and the reflection unit array characteristic information of the reconfigurable intelligent surface, the signal reflection matrix of the reconfigurable intelligent surface, the antenna array characteristic information of the half-duplex decoding forwarding relay and the position information of the half-duplex decoding forwarding relay, the channel characteristic information and the system working wavelength, a third indirect link channel matrix between the half-duplex decoding forwarding relay and the receiving end is calculated;

And calculating the reachable rate of the second receiving end according to the channel matrix of the fifth direct link, the channel matrix of the third indirect link, the covariance matrix of the transmitting signal and the noise power.

Optionally, the method further comprises:

according to the fourth direct link channel matrix, the channel matrix of the second indirect link, the transmitting signal covariance matrix and the noise power, performing iterative computation to obtain a plurality of fourth candidate reachable rates until a converged fourth candidate reachable rate is obtained or a preset iteration number is reached;

taking the largest of the plurality of fourth candidate reachable rates as the second relay reachable rate;

according to the fifth direct link channel matrix, the channel matrix of the third indirect link, the transmitting signal covariance matrix and the noise power, performing iterative computation to obtain a plurality of fifth candidate reachable rates until a converged fifth candidate reachable rate is obtained or a preset iteration number is reached;

taking the largest of the fifth candidate reachable rates as the reachable rate of the second receiving end;

wherein, the fourth candidate reachable rate is obtained by any iterative calculation, which comprises the following steps:

Optimizing the emission signal covariance matrix and the signal reflection matrix of the reconfigurable intelligent surface to obtain an optimized emission signal covariance matrix and an optimized signal reflection matrix of the reconfigurable intelligent surface;

calculating to obtain a fourth candidate reachable rate according to the optimized emission signal covariance matrix and the signal reflection matrix of the optimized reconfigurable intelligent surface;

wherein, the fifth candidate reachable rate is obtained by any iterative calculation, which comprises the following steps:

and calculating to obtain a fifth candidate reachable rate according to the covariance matrix of the optimized transmitting signal and the signal reflection matrix of the optimized reconfigurable intelligent surface.

Based on the same inventive concept, the present application further provides a communication policy selection device, including:

the acquisition module is configured to acquire the characteristic information of the antenna array of the transmitting end, the position information of the transmitting end, the characteristic information of the antenna array of the receiving end, the position information of the receiving end, the characteristic information of a channel and the working wavelength of the system;

The strategy determining module is configured to determine a first communication strategy for realizing communication through a reconfigurable intelligent surface, determine a second communication strategy for realizing communication through a half-duplex decoding forwarding relay and determine a third communication strategy for jointly realizing communication through the reconfigurable intelligent surface and the half-duplex decoding forwarding relay according to the transmitting end antenna array characteristic information, the transmitting end position information, the receiving end antenna array characteristic information and the receiving end position information;

a rate calculation module configured to calculate a first achievable rate of the first communication policy, a second achievable rate of the second communication policy, and a third achievable rate of the third communication policy;

the comparison module is configured to determine a target maximum rate according to the first reachable rate, the second reachable rate and the third reachable rate, and determine a communication strategy corresponding to the target maximum rate as a target communication strategy;

and the deployment module is configured to deploy the communication element according to the target communication strategy.

Based on the same inventive concept, the application also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the communication strategy selection method according to any one of the above.

Based on the same inventive concept, the present application also provides a non-transitory computer readable storage medium storing computer instructions for causing the computer to execute any one of the above-described communication policy selection methods.

From the foregoing, it can be seen that, by using the communication policy selection method, apparatus, electronic device and storage medium provided in the present application, first, by respectively providing a first communication policy for implementing communication through a reconfigurable intelligent surface according to the condition of a transceiver device, the channel characteristic and the condition of a system operating wavelength, a second communication policy for implementing communication through a half-duplex decoding forwarding relay is provided, and a third communication policy for implementing communication through the reconfigurable intelligent surface and the half-duplex decoding forwarding relay is provided together. The best strategy selection is then made by calculating the maximum achievable rates for the three strategies. By the method, the optimal auxiliary communication element can be determined in advance according to the specific condition of the communication system, and the optimal deployment scheme of the communication system can be obtained by deploying according to the optimal auxiliary communication element.

Drawings

In order to more clearly illustrate the technical solutions of the present application or related art, the drawings that are required to be used in the description of the embodiments or related art will be briefly described below, and it is apparent that the drawings in the following description are only embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort to those of ordinary skill in the art.

Fig. 1 is a flow chart of a communication policy selection method according to an embodiment of the present application;

fig. 2 is a schematic system architecture diagram of a first communication policy according to an embodiment of the present application;

fig. 3 is a schematic system architecture diagram of a second communication policy according to an embodiment of the present application;

FIG. 4a is a schematic diagram of a system architecture of a third communication strategy according to an embodiment of the present application;

FIG. 4b is a schematic diagram of a system architecture of a third communication strategy according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of a communication policy selection device according to an embodiment of the present application;

fig. 6 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail below with reference to the accompanying drawings.

It should be noted that unless otherwise defined, technical or scientific terms used in the embodiments of the present application should be given the ordinary meaning as understood by one of ordinary skill in the art to which the present application belongs. The terms "first," "second," and the like, as used in embodiments of the present application, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

According to the background art, with the development of mobile communication technology, the target network capacity of the wireless network is greatly improved, which puts higher demands on the transmission capability of the wireless network. In the related art, signal propagation capability is generally improved by enhancing the capabilities of the base station and the terminal. Meanwhile, some related art propose to remodel wireless channels with reconfigurable intelligent surfaces. The reconfigurable smart surface (Reconfigurable Intelligent Surface, RIS) is a large, thin supersurface made of metal or dielectric material, consisting of a set of passive sub-wavelength scattering elements with specially designed physical structures. The passive sub-wavelength scattering element is made of sub-wavelength artificial materials arranged according to a preset geometric structure, and one can dynamically control the elements in a software-defined mode so as to change the electromagnetic characteristics of incident radio frequency signal reflection. Experiments show that the reconfigurable intelligent surface technology can play an important role in the aspects of coverage rate improvement, interference suppression, safety enhancement and the like of a communication system, and the transmission capacity of the communication system can be greatly improved by utilizing the reconfigurable intelligent surface to remodel a wireless channel. On the other hand, some related arts suggest that, in some cases, half Duplex (HD) Decode-and-Forward (DF) relay may replace it. That is, assisting a communication system by the RIS technique is not always an optimal solution depending on the characteristics of the communication system.

Therefore, the application provides a communication strategy selection method, which is used for respectively calculating and comparing the reachable rate of a communication system when the communication system is assisted by three modes of RIS, HD DF relay and RIS and HD DF relay combination under the conditions of preset transmitting end antenna array characteristic information, transmitting end position information, receiving end antenna array characteristic information, receiving end position information, channel characteristic information and system working wavelength of the communication system. And selecting an optimal scheme according to the calculated reachable rate, and further deploying a communication system according to the optimal scheme.

The following describes in detail, by way of specific embodiments, the technical solutions of one or more embodiments of the present application.

Referring to fig. 1, a communication policy selection method according to an embodiment of the present application includes the following steps:

step S101: and acquiring the characteristic information of the antenna array of the transmitting end, the position information of the transmitting end, the characteristic information of the antenna array of the receiving end, the position information of the receiving end, the characteristic information of a channel and the working wavelength of the system.

In this step, the characteristic information of the transmitting end, the receiving end and the channel is first obtained, and the system operating wavelength is first obtained. The characteristic information of the sending end and the receiving end mainly comprises: and acquiring the characteristic information of the antenna array at the transmitting end and the position information of the transmitting end, and the characteristic information of the antenna array at the receiving end and the position information of the receiving end.

Step S102: according to the characteristic information of the antenna array of the transmitting end and the position information of the transmitting end, the characteristic information of the antenna array of the receiving end and the position information of the receiving end, the channel characteristic information and the working wavelength of the system, a first communication strategy for realizing communication through a reconfigurable intelligent surface, a second communication strategy for realizing communication through a half-duplex decoding forwarding relay and a third communication strategy for jointly realizing communication through the reconfigurable intelligent surface and the half-duplex decoding forwarding relay are determined.

In this step, the determination of the communication policy is performed based on all the information obtained in step S101. In some embodiments, communication will be implemented through the RIS as a first communication policy, communication will be implemented through the HD DF relay as a second communication policy, and communication will be implemented through the RIS and HD DF relay together as a third communication policy.

Step S103: a first achievable rate of the first communication policy, a second achievable rate of the second communication policy, and a third achievable rate of the third communication policy are calculated.

Step S102 has determined three communication strategies. In this step, the achievable rates are calculated for the above three communication strategies, respectively.

The method for calculating the first communication strategy, namely realizing communication through RIS assistance, specifically comprises the following steps: firstly, determining the deployment schemes of the receiving end, the transmitting end and the RIS determined by the first communication strategy according to the information obtained in the step S101. Then according to the antenna array characteristic information of the transmitting end, the position information of the transmitting end, the antenna array characteristic information of the receiving end, the position information of the RIS, the reflection unit array characteristic information of the RIS and the signal reflection matrix of the RIS, as well as the system working wavelength and the channel characteristic information, the direct link channel matrix from the transmitting end to the receiving end, the channel matrix from the transmitting end to the RIS and the channel matrix from the RIS to the receiving end are calculated, and then the reachable rate is calculated according to all the obtained channel matrices, the covariance matrix of the transmitting signals and the noise power through formulas. In some embodiments, the plurality of candidate achievable rates may be obtained by optimizing the transmit signal covariance matrix and the signal reflection matrix of the RIS, and selecting a maximum target achievable rate from the plurality of candidate achievable rates.

In particular, with an RIS-assisted communication system, the signal vector at the receiving end can be expressed as:

y＝(H _DIR +H _NDIR )x+n＝Hx+n

Wherein, the liquid crystal display device comprises a liquid crystal display device,

is a transmit signal vector; />

Is according to CN (0, N ₀ I) Distributed noise vector, where 0 is zero matrix, N ₀ Is the noise power, I is the identity matrix; />

Is the overall channel matrix of the system,

channel matrix representing direct link between transmitting and receiving end +.>

A channel matrix representing an indirect link between a transmitting end and a receiving end via RIS reflection.

H when the rice fading channel model is adopted _DIR The method can be calculated by the following formula:

H _DIR,LOS the line-of-sight component matrix representing the channel matrix of the direct link between the transmitting end and the receiving end can be calculated by the following formula:

j represents an imaginary unit, d _r,t Is the distance between the r-th receive antenna and the t-th transmit antenna, λ represents the system operating wavelength. H _DIR,NLOS Non-line-of-sight component matrix representing channel matrix of direct link between transmitting end and receiving end, H _DIR,NLOS The elements of (2) are independent and distributed identically to CN (0, 1). Propagation conditions of a wireless communication system are generally divided into two environments, line of Sight (LOS) and non-Line of Sight (Non Line of Sight, NLOS). Under the LOS environment, the wireless signal is transmitted in a straight line between a transmitting end and a receiving end without shielding; in NLOS environments, the wireless signal can only reach the receiving end by avoiding obstacles through reflection, scattering and diffraction modes. The wireless signal at this time is received through various paths. There is a main direct signal in the rice channel, and several multipath components. K represents the rice factor of the communication system.

The free space path loss representing the direct link of the signal from the transmitting end to the receiving end can be calculated by the following formula:

alpha represents the path loss index of the direct link, d ₀ Is the distance between the transmit array midpoint and the receive array midpoint, and can be calculated by the formula:

calculated, d _SD Indicating the distance between the transmitting end and the receiving end, l _s Midpoint of antenna array representing transmitting end and containingDistance between planes of RIS, l _d Representing the distance between the midpoint of the antenna array at the receiving end and the plane containing the RIS.

Wherein H is _NDIR The method can be calculated by the following formula:

representing the channel matrix between the transmitting end and the RIS, < >>

Representing the channel matrix between the RIS and the receiving end. />

The signal reflection matrix representing RIS, θ represents the phase shift corresponding to each reflection unit in RIS, and the vector of its composition can be expressed by the following formula: />

β _NDIR ^-1 The free space path loss representing the indirect link of the signal from the transmitting end to the RIS to the receiving end can be calculated by the following formula:

d ₁ the distance from the center of the antenna array at the transmitting end to the center of the reflection unit array at the RIS can be calculated by the following formula:

d ₂ the distance from the center of the reflection unit array representing the RIS to the center of the antenna array at the receiving end can be calculated by the following formula To: />

Wherein d _SD Represents the distance between the transmitting end and the receiving end, d _ris Representing the distance l between the midpoint of the reflective element array of the RIS and the plane of the antenna array containing the transmitting end _d Representing the distance between the midpoint of the antenna array at the receiving end to the plane containing the RIS. Kappa (kappa) ₁ Is the angle between the vector perpendicular to the RIS and the direction of the incident wave from the center of the antenna array at the transmitting end to the center of the reflective element array of the RIS. Kappa (kappa) ₂ Is the angle between the reflected wave direction from the center of the RIS reflection unit array to the center of the antenna array at the receiving end and the vector perpendicular to the RIS. Lambda represents the system operating wavelength.

When the input end and the receiving end can obtain the information of the whole channel matrix of the communication system, the reachable rate of the system can be calculated by the following formula:

h denotes the overall channel matrix of the communication system, G denotes the input covariance matrix, and can be represented by the formula g=e { xx } ^H Calculated, N ₀ Which represents the power of the noise and,

representing the calculation->

Is a determinant of (2).

On this basis, the optimized achievable rate can also be calculated by projection gradient method (Projected Gradient Method, PGM), comprising the following steps:

the optimization problem can be expressed first by the following formula:

det(I+Z(θ)GZ ^H (θ)) means calculating i+z (θ) GZ ^H Determinant of (θ). Z (θ) can be calculated by the following formula:

representing the channel matrix between the RIS and the receiving end.

The set of phase shifts and the set of input covariance matrices for each reflection element in the RIS can be defined as:

tr (G). Ltoreq.P represents that the constraint condition of the trace of the input covariance matrix is smaller than or equal to the maximum average transmitting power of the transmitting end S, and G.gtoreq.0 represents that G is a semi-positive definite matrix.

The feasible set of optimized reachable rates is the Cartesian product of Θ and f.

In some embodiments, θ when the optimization calculation is performed by the PGM algorithm _n+1 And G _n+1 Can be expressed as:

and->

μ represents a predetermined step size. Initial value of θ ₀ Initial value G of G ₀ Can be obtained by a manually predetermined mode. Function P _U (U) represents the Euclidean projection from point U to set U, with

x is a point on the set U, and the significance of the Euclidean projection of the point U to the set U is: the point x which minimizes the Euclidean norm of x-u is P _U (u). f (θ, G) is relative to θ ^* And G ^* The gradients of (2) are respectively: />

And->

Wherein K (θ, G) = (i+z (θ) GZ ^H (θ)) ^-1 。

Thus, the first and second substrates are bonded together,

computing Euclidean projection of point u to set Θ, thereby computing in algorithm

Projection at Θ ∈>

At the time of +. >

P _Θ (u) is vector->

The method comprises the following steps:

computing the projection of Y onto the set f, thereby computing the algorithm

Projection at f

At the time of given->

The projection of Y onto r is a solution to the following problem:

let y=u Σu ^H For the eigenvalue decomposition of Y, where

For some->

G=udu can be written ^H ，/>

The following formula is calculated:

equivalently, the following formula is calculated:

in some embodiments, the above problem may be solved by a water filling algorithm, the calculation formula is as follows:

d _i ＝(σ-γ) ₊ ,i＝1,…,N _t

the preset gamma is more than or equal to 0 and is the water level.

To speed up PGM convergence, a traceback line search is used in each iteration to find potentially larger steps. Predetermined L _O >0,δ>0, ρ ε (0, 1). In the algorithm, the step size μ is replaced with

Wherein k is _n Is satisfied with f (theta) _n+1 ,G _n+1 )≥f(θ _n ,G _n )+δ(||θ _n+1 -θ _n || ² +||G _n+1 -G _n || ² ) Is a minimum non-negative integer of (2). When f (theta) _n+1 ,g _n+1 )≥f(θ _n ,g _n )+δ(||θ _n+1 -θ _n || ² +||G _n+1 -G _n || ² ) Or L _O <10 ^-4 Updating the G, theta and the reachable rate value; otherwise, the step length is reduced to make L _O ＝L _O ρ. Repeating the iteration steps until the obtained candidate reachable rate converges or the iteration times are reached, and stopping the iterative computation. And finally, selecting the maximum candidate reachable rate from all candidate reachable rates obtained in the iterative computation as a target reachable rate. Similar calculation methods may be utilized in this application to calculate the achievable rates for schemes that utilize the first policy to effect communication. According to the above, in some embodiments, in addition to the information acquired in step S101, there may be To obtain the maximum average transmitting power of the transmitting end and the preset noise power. And meanwhile, the positions of the receiving end, the transmitting end and the RIS can be determined according to the first communication strategy.

Referring to fig. 2, in some embodiments, the antenna array of the transmitting end S and the antenna array of the receiving end D are placed on vertical walls parallel to each other, and a distance between them is denoted as D _SD . The antenna array of the transmitting end S and the antenna array of the receiving end D are parallel to the ground and located at the same height, and are uniform linear arrays. The antenna array of the transmitting terminal S comprises N _t Root antenna with spacing s _t The method comprises the steps of carrying out a first treatment on the surface of the The antenna array of the receiving end D comprises N _r Root antenna with spacing s _r 。s _t And s _r Are equal to lambda/2, where lambda represents the operating wavelength. RIS comprises N _a ×N _a A total number of reflecting units N _ris Wherein all the reflecting units have the dimensions of

The spacing between the centers of adjacent reflecting units is lambda/2. The distance between the center position of the RIS and the plane of the antenna array containing the transmitting end S is d _ris The distance between the center point of the antenna array of the transmitting end S and the plane containing the RIS is l _s The distance between the center point of the antenna array of the receiving end D and the plane containing the RIS is l _d . In some embodiments, where an RIS-assisted communication system is utilized, reflective elements of the RIS may be desirable, each of which may independently affect the phase and reflection angle of the incident wave.

Firstly, according to the antenna array characteristic information and the position information of a transmitting end S, the antenna array characteristic information, the position information, the system working wavelength and the channel characteristic information of a receiving end D, a direct link channel matrix H between the transmitting end S and the receiving end D is calculated _SD . Meanwhile, the maximum average transmitting power and the noise power of a transmitting end are obtained, and an initial transmitting signal covariance matrix is calculated according to the following formula:

wherein I represents an identity matrix, N _t For the number of antennas at the transmitting end,

represents the maximum average transmit power, G _a,0 Representing the covariance matrix of the initial transmit signal. Generating a channel matrix H between the transmitting end S and the RIS according to the antenna array characteristic information and the position information of the transmitting end S and the position information of the receiving end D and the RIS, the reflection unit array characteristic information, the initial signal reflection matrix, the channel characteristic information and the system working wavelength _SI And a channel matrix H between RIS and receiving end D _ID 。

The initial achievable rate is calculated according to the following formula:

H ₁ the channel matrix representing the system is complete can be calculated by the formula: h ₁ ＝H _SD +H _SID ，

Channel matrix representing direct link between transmitting end S and receiving end D +. >

The channel matrix representing the indirect link between the transmitting end S and the receiving end D after RIS reflection is calculated by the following formula:

wherein F (θ) ₀ ) Representing RISThe initial signal reflection matrix is used to reflect the signal,

/>

in some embodiments, it may be considered that the signal reflected from the RIS reflection unit is ideal, without power loss, at the time of calculation>

Wherein->

Is the phase shift caused by the reflection unit of the first RIS.

N ₀ Representing the noise power.

In some embodiments, the initial achievable rate calculated by the above formula is taken as the first achievable rate.

For the C obtained _prev 、G _a,0 、θ ₀ Recording is performed.

In other embodiments, the optimized achievable rate is obtained by iterative calculation through PGM algorithm, and the specific steps include:

obtaining iteration optimization parameters delta, iteration times no_iter and initial step length L _O >0，ρ∈(0,1)。

Then in each iteration, calculation is performed by means of the achievable rate optimization function

And->

The above-mentioned achievable rate optimization function is:

f(θ,G _a ) Relative to theta ^* The gradient of (2) is:

f(θ,G _a ) Relative to g _a ^* The gradient of (2) is:

wherein K (θ, G) _a )＝(I+Z(θ)G _a Z ^H (θ)) ^-1 ，

According to the two gradient values obtained by calculation, a new emission signal covariance matrix and a phase shift corresponding to each reflection unit in RIS are obtained by calculation according to the following formula:

wherein L is _O Representing a predetermined step size, f' may be expressed as:

then use the newly obtained G _a,new 、θ _new Calculating an optimal achievable rate according to the formula:

for the above G _a,new 、θ _new C _new Recording is performed.

And carrying out iterative computation for optimizing the reachable rate according to the steps, and stopping iterative computation when the optimizing reachable rate converges or reaches the preset iteration times.

In some embodiments, to accelerate the convergence speed of the PGM algorithm, a potentially larger step size may be found by backtracking search at each iteration, which includes the following specific steps: in response to determining C _new -G _prev ≥δ(||θ _new -θ|| ² +||G _a,new -G _a || ² ) Or L _O <10 ^-4 Stopping updating step length and recording G _a,new 、θ _new 、C _new . In response to determining C _new -C _prev <δ(||θ _new -θ|| ² +||G _a,new -G _a || ² ) And L is _O ≥10 ^-4 Then the update step length is L _O ＝L _O ρ。

Repeating the above calculation until C is obtained _new And (5) converging or reaching the iteration times, and stopping the iterative computation.

A first set of achievable rates consisting of an initial achievable rate and a plurality of optimized achievable rates is obtained by the steps described above.

In some embodiments, to improve reliability, a channel implementation number no_mat may be predetermined. The no _ mat achievable rates are obtained either at the calculation of the initial achievable rate or at each iteration of the calculation. And when recording, calculating the average reachable speed result of each round, namely recording the result of dividing the reachable speed of each round by the no_mat.

Calculating a second achievable rate of the second communication policy, including the steps of:

firstly, the placement positions of the relay of the transmitting end S, the receiving end D and the HD DF are determined according to a second communication strategy.

In some embodiments, referring to fig. 3, the placement method of the transmitting end S and the receiving end D is consistent with the placement method of the receiving end in the above method; the method for placing the HD DF relay is identical to the method for placing the RIS in the above method, and will not be described here.

Firstly, calculating the reachable rate at the relay to obtain the relay reachable rate. According to the characteristic information and the position information of the antenna array of the transmitting end S, the position information of the relay of the HD DF, the characteristic information of the antenna array, the channel characteristic information and the system working wavelength, calculating a channel matrix H between the transmitting end S and the relay of the HD DF _SR 。

The initial achievable rate is calculated according to the following formula:

covariance matrix G of initial transmitting signal _b,0 The method can be obtained by the following calculation formula:

represents the maximum average transmit power, G _b,0 Representing the covariance matrix of the initial transmit signal.

In some embodiments, the initial achievable rate calculated by the above formula is taken as the first relay achievable rate.

For the C obtained _prev 、G _b,0 Recording is performed.

In other embodiments, the optimal achievable rates are obtained by iterative computation using PGM algorithm, and a new G is calculated based on the achievable rate optimization function _b,new ，G _b,new G of the first communication policy _a,new The calculation method of (2) is consistent and will not be described in detail herein.

Then, carrying out iterative calculation by using a formula:

the iterative calculation method is consistent with the first reachable rate of the first communication strategy, and will not be described herein.

After stopping the iterative computation, a set of relay reachable rates consisting of the initial reachable rate and a plurality of optimized reachable rates is obtained. And selecting the reachable rate with the largest value as the relay reachable rate.

And then calculating the reachable rate at the receiving end to obtain the reachable rate of the receiving end. According to the antenna array characteristic information and the position information of the receiving end D, the position information of the HD DF relay, the antenna array characteristic information, the channel characteristic information and the system working wavelength, calculating the channel matrix H of the direct link between the HD DF relay and the receiving end D _RD 。

The initial achievable rate is calculated according to the following formula:

wherein H is ₂ ＝H _SD +H _RD . Wherein H is _SD Channel matrix representing direct link between transmitting end S and receiving end D, calculating mode and calculating H in the above-mentioned first reachable rate _SD The method of (2) is consistent and will not be described in detail herein.

In some embodiments, the initial achievable rate calculated by the above formula is used as the first receiving end achievable rate.

For the C obtained _prev 、G _b,0 Recording is performed.

Then, carrying out iterative calculation by using a formula:

After stopping the iterative computation, a set of terminal reachable rates consisting of the initial reachable rate and a plurality of optimized reachable rates is obtained. And selecting the achievable rate with the largest value as the terminal achievable rate.

Finally, the relay reachable rate and the terminal reachable rate are compared, with the smaller value being the second reachable rate.

Calculating a third achievable rate of the third communication strategy, including the following steps:

firstly, the placement positions of a transmitting end S, a receiving end D, an HD DF relay and an RIS are determined according to a third communication strategy.

In some embodiments, referring to fig. 4a and fig. 4b, the placement method of the transmitting end S and the receiving end D, RIS is identical to the placement method of the transmitting end S and the receiving end D, RIS in the first communication policy, which is not described herein. HD DF relay is placed on a plane opposite to RIS with a distance l between the plane containing the antenna array of the relay and the plane containing RIS _p 。

First calculateAnd obtaining the reachable rate of the relay. Generating a channel matrix H of a direct link between the transmitting end S and the HD DF relay according to the antenna array characteristic information and the position information of the transmitting end S, the position information of the HD DF relay, the antenna array characteristic information, the channel characteristic information and the system working wavelength _SR,2 Generating a channel matrix H between the transmitting terminal S and the RIS according to the antenna array characteristic information and the position information of the transmitting terminal S, the position information of the RIS, the reflection unit array characteristic information, the signal reflection matrix, the channel characteristic information and the system working wavelength _SI Generating a channel matrix H between the RIS and the HD DF relay according to the position information of the RIS, the characteristic information of the reflecting unit array, the signal reflecting matrix, the position information of the HD DF relay, the characteristic information of the antenna array, the characteristic information of the channel and the system operating wavelength _IR 。

The initial achievable rate is calculated according to the following formula:

/>

wherein H is ₃ ＝H _SR,2 +H _SIR ，

F(ω ₀ ) An initial signal reflection matrix representing RIS, +.>

In some embodiments, the initial achievable rate calculated by the above formula is used as the second relay achievable rate.

For the C obtained _prev 、G _b,0 、ω ₀ Recording is performed.

In other embodiments, the optimal achievable rates are obtained by iterative computation using PGM algorithm, and a new G is calculated based on the achievable rate optimization function _b,new 、ω _new ，G _b,new 、ω _new G of the first communication policy _a,new 、θ _new The calculation method of (2) is consistent and will not be described in detail herein.

Then, carrying out iterative calculation by using a formula:

And then calculating the reachable rate at the receiving end to obtain the reachable rate of the receiving end. Generating a channel matrix H of a direct link between the HD DF relay and the receiving end D according to the antenna array characteristic information and the position information of the receiving end D, the position information of the HD DF relay, the antenna array characteristic information, the channel characteristic information and the system working wavelength _RD,2 Calculating a channel matrix H between the HD DF relay and the RIS according to the antenna array characteristic information and the position information of the receiving end D, the position information of the RIS, the reflection unit array characteristic information and the signal reflection matrix of the receiving end D, the position information of the HD DF relay, the antenna array characteristic information, the channel characteristic information and the system working wavelength _RI And a channel matrix H between RIS and receiving end D _ID 。

The initial achievable rate is calculated according to the following formula:

wherein H is ₄ ＝H _RD,2 +H _RID ，

F(η ₀ ) An initial signal reflection matrix representing RIS, +. >

In some embodiments, the initial achievable rate calculated by the above formula is used as the second receiving end achievable rate.

For the C obtained _prev 、G _b,0 、η ₀ Recording is performed.

In other embodiments, the optimal achievable rates are obtained by iterative computation using PGM algorithm, and a new G is calculated based on the achievable rate optimization function _b,new 、η _new ，G _b,new 、η _new G of the first communication policy _a,new 、θ _new The calculation method of (2) is consistent and will not be described in detail herein.

Then, carrying out iterative calculation by using a formula:

Finally, the relay reachable rate and the terminal reachable rate are compared, with the larger value being the third reachable rate.

Step S104: and determining a target maximum rate according to the first reachable rate, the second reachable rate and the third reachable rate, and determining a communication strategy corresponding to the target maximum rate as a target communication strategy.

Step S105: and deploying the communication element according to the target communication strategy.

It should be noted that, the method of the embodiments of the present application may be performed by a single device, for example, a computer or a server. The method of the embodiment can also be applied to a distributed scene, and is completed by mutually matching a plurality of devices. In the case of such a distributed scenario, one of the devices may perform only one or more steps of the methods of embodiments of the present application, and the devices may interact with each other to complete the methods.

It should be noted that some embodiments of the present application are described above. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments described above and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Based on the same inventive concept, the application also provides a communication strategy selection device corresponding to the method of any embodiment.

Referring to fig. 5, the communication policy selection device includes:

an acquisition module 11 configured to acquire transmitting-end antenna array characteristic information, transmitting-end position information, receiving-end antenna array characteristic information, receiving-end position information, channel characteristic information, and system operating wavelength;

a policy determining module 12 configured to determine a first communication policy for implementing communication through a reconfigurable intelligent surface, determine a second communication policy for implementing communication through a half-duplex decoding forwarding relay, and determine a third communication policy for implementing communication together through a reconfigurable intelligent surface and a half-duplex decoding forwarding relay according to the transmitting end antenna array characteristic information, the transmitting end location information, the receiving end antenna array characteristic information, the receiving end location information, the channel characteristic information, and the system operating wavelength;

a rate calculation module 13 configured to calculate a first achievable rate of the first communication policy, a second achievable rate of the second communication policy, and a third achievable rate of the third communication policy;

A comparison module 14 configured to determine a target maximum rate according to the first achievable rate, the second achievable rate and the third achievable rate, and determine a communication policy corresponding to the target maximum rate as a target communication policy;

a deployment module 15 configured to deploy the communication elements according to the target communication policy.

For convenience of description, the above devices are described as being functionally divided into various modules, respectively. Of course, the functions of each module may be implemented in the same piece or pieces of software and/or hardware when implementing the present application.

The device of the foregoing embodiment is configured to implement the corresponding communication policy selection method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which is not described herein.

Based on the same inventive concept, the application also provides an electronic device corresponding to the method of any embodiment, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor implements the communication policy selection method of any embodiment when executing the program.

Fig. 6 shows a more specific hardware architecture of an electronic device according to this embodiment, where the device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 implement communication connections therebetween within the device via a bus 1050.

The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit ), microprocessor, application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or one or more integrated circuits, etc. for executing relevant programs to implement the technical solutions provided in the embodiments of the present disclosure.

The Memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory ), static storage device, dynamic storage device, or the like. Memory 1020 may store an operating system and other application programs, and when the embodiments of the present specification are implemented in software or firmware, the associated program code is stored in memory 1020 and executed by processor 1010.

The input/output interface 1030 is used to connect with an input/output module for inputting and outputting information. The input/output module may be configured as a component in a device (not shown) or may be external to the device to provide corresponding functionality. Wherein the input devices may include a keyboard, mouse, touch screen, microphone, various types of sensors, etc., and the output devices may include a display, speaker, vibrator, indicator lights, etc.

Communication interface 1040 is used to connect communication modules (not shown) to enable communication interactions of the present device with other devices. The communication module may implement communication through a wired manner (such as USB, network cable, etc.), or may implement communication through a wireless manner (such as mobile network, WIFI, bluetooth, etc.).

Bus 1050 includes a path for transferring information between components of the device (e.g., processor 1010, memory 1020, input/output interface 1030, and communication interface 1040).

It should be noted that although the above-described device only shows processor 1010, memory 1020, input/output interface 1030, communication interface 1040, and bus 1050, in an implementation, the device may include other components necessary to achieve proper operation. Furthermore, it will be understood by those skilled in the art that the above-described apparatus may include only the components necessary to implement the embodiments of the present description, and not all the components shown in the drawings.

The electronic device of the foregoing embodiment is configured to implement the corresponding communication policy selection method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which is not described herein.

Based on the same inventive concept, corresponding to any of the above embodiments of the method, the present application further provides a non-transitory computer readable storage medium storing computer instructions for causing the computer to perform the communication policy selection method according to any of the above embodiments.

The computer readable media of the present embodiments, including both permanent and non-permanent, removable and non-removable media, may be used to implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device.

The storage medium of the foregoing embodiments stores computer instructions for causing the computer to execute the communication policy selection method described in any one of the foregoing embodiments, and has the advantages of the corresponding method embodiments, which are not described herein.

Those of ordinary skill in the art will appreciate that: the discussion of any of the embodiments above is merely exemplary and is not intended to suggest that the scope of the application (including the claims) is limited to these examples; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the present application, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

Additionally, well-known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown within the provided figures, in order to simplify the illustration and discussion, and so as not to obscure the embodiments of the present application. Furthermore, the devices may be shown in block diagram form in order to avoid obscuring the embodiments of the present application, and this also takes into account the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform on which the embodiments of the present application are to be implemented (i.e., such specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the application, it should be apparent to one skilled in the art that embodiments of the application can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative in nature and not as restrictive.

While the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of those embodiments will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

The present embodiments are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Accordingly, any omissions, modifications, equivalents, improvements and/or the like which are within the spirit and principles of the embodiments are intended to be included within the scope of the present application.

Claims

1. A communication policy selection method, comprising:

2. The method of claim 1, wherein calculating a first achievable rate for the first communication policy comprises:

3. The method according to claim 2, wherein the method further comprises:

4. The method of claim 1, wherein calculating a second achievable rate for the second communication policy comprises:

5. The method according to claim 4, wherein the method further comprises:

6. The method of claim 1, wherein calculating a third achievable rate for the third communication policy comprises:

7. The method of claim 6, wherein the method further comprises:

8. A communication policy selection device, comprising:

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1 to 7 when the program is executed by the processor.

10. A non-transitory computer readable storage medium storing computer instructions for causing a computer to perform the method of any one of claims 1 to 7.