阅读说明：本技术 一种基于可重构反射超表面的车联网通信优化方法及系统 (Vehicle networking communication optimization method and system based on reconfigurable reflection super surface ) 是由 邓若琪 张雨童 张浩波 于 2021-09-07 设计创作，主要内容包括：本发明涉及一种基于可重构反射超表面的车联网通信优化方法及系统。该方法包括：根据车联网通信系统确定每个V2I链路中车辆收到的信号和每个V2V用户收到的信号；根据每个V2V用户收到的信号以及每个V2I链路中车辆收到的信号确定的数据速率确定总数据速率；以总数据速率最大为目标,以V2V链路中发射的功率和RIS中每个超材料辐射单元的相位配置为变量,以基站发射端的总功率和V2V链路中发射的功率阈值为约束条件,构建目标函数；对目标函数进行迭代优化确定V2V链路中发射的目标功率和RIS中每个超材料辐射单元的目标相位配置。本发明提升了V2V通信系统的总数据速率。(The invention relates to a vehicle networking communication optimization method and system based on a reconfigurable reflection super surface. The method comprises the following steps: determining, from the internet of vehicles communication system, signals received by vehicles in each V2I link and signals received by each V2V user; determining a total data rate from the signals received by each V2V user and the data rates determined from the signals received by the vehicles in each V2I link; constructing an objective function by taking the maximum total data rate as an objective, configuring the power transmitted in the V2V link and the phase of each metamaterial radiation unit in the RIS as variables, and taking the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions; iterative optimization of the objective function determines the target power emitted in the V2V link and the target phase configuration for each metamaterial radiating element in the RIS. The invention improves the total data rate of the V2V communication system.)

1. A vehicle networking communication optimization method based on a reconfigurable reflection super surface is characterized by comprising the following steps:

acquiring a vehicle networking communication system;

determining, from the internet of vehicles communication system, signals received by vehicles in each V2I link and signals received by each V2V user;

determining an overall data rate in the internet of vehicles communication system from the data rate determined from the signals received by each V2V user and the signals received by the vehicles in each V2I link;

constructing an objective function by taking the maximum total data rate as an objective, configuring the power transmitted in the V2V link and the phase of each metamaterial radiation unit in the RIS as variables, and taking the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions;

the target power emitted in the V2V link and the target phase configuration of each metamaterial radiating element in the RIS are determined from the target function.

2. The vehicle networking communication optimization method based on the reconfigurable reflection super surface according to claim 1, wherein the vehicle networking communication system comprises: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS.

3. The method for optimizing communication in the internet of vehicles based on the reconfigurable reflection super surface according to claim 1, wherein the determining the target power emitted in the V2V link and the target phase configuration of each metamaterial radiating element in the RIS according to the target function specifically comprises:

and performing iterative optimization on the objective function until the difference between the objective functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

4. A vehicle networking communication optimization system based on a reconfigurable reflection super surface, comprising:

the Internet of vehicles communication system acquisition module is used for acquiring the Internet of vehicles communication system;

a signal determination module for determining signals received by vehicles in each V2I link and signals received by each V2V user according to the Internet of vehicles communication system;

a total data rate determination module for determining a total data rate in the internet of vehicles communication system based on the data rate determined from the signals received by each V2V user and the signals received by the vehicles in each V2I link;

the target function building module is used for building a target function by taking the maximum total data rate as a target, the power transmitted in the V2V link and the phase configuration of each metamaterial radiation unit in the RIS as variables and the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions;

and the scheme determining module is used for determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS according to the target function.

5. The reconfigurable reflective super surface-based vehicle networking communication optimization system according to claim 4, wherein the vehicle networking communication system comprises: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS.

6. The system of claim 4, wherein the solution determination module specifically comprises:

and the scheme determining unit is used for performing iterative optimization on the objective function until the difference between the objective functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

Technical Field

The invention relates to the field of vehicle networking communication, in particular to a vehicle networking communication optimization method and system based on a reconfigurable reflection super surface.

Background

The explosive increase of the number of mobile devices has caused the urgent need of high-speed and seamless data service for future wireless systems, and how to improve the link quality in a complex time-varying wireless environment becomes a problem to be solved urgently. Existing methods for enhancing a target signal all rely on additional hardware, which inevitably causes problems of high power consumption and high complexity of signal processing.

In recent years, a new transmission technology RIS has come to be developed, which shapes the propagation environment into an ideal form by controlling the electromagnetic response of a plurality of RIS units. In particular, the RIS is an ultra-thin surface embedded with a plurality of RIS elements whose electromagnetic response (e.g., phase shift) can be controlled by simple programmable diodes. Unlike scattered waves emitted by conventional antennas, in an RIS-based programmable propagation environment, the received signal is reflected directly to the receiver, no additional hardware power consumption is generated, and link quality and coverage area are improved.

Device-to-device (V2V) communication is considered an important feature of future cellular networks. On the basis of a cellular network supporting V2V, the source and destination ends of the link can communicate directly with each other by multiplexing the frequency band of the access link without bypassing the base station. Therefore, the method can fully utilize the scarce frequency spectrum resources, obviously improve the network throughput and effectively enlarge the coverage area. However, one key issue that has not been addressed is the increased interference caused by V2V communications.

In summary, there is a need for a method or system for optimizing communication in a vehicle networking system to reduce interference to further increase the overall data rate of the V2V communication system.

Disclosure of Invention

The invention aims to provide a vehicle networking communication optimization method and system based on a reconfigurable reflection super surface, which can improve the total data rate of a V2V communication system.

In order to achieve the purpose, the invention provides the following scheme:

a vehicle networking communication optimization method based on a reconfigurable reflection super surface comprises the following steps:

acquiring a vehicle networking communication system;

determining, from the internet of vehicles communication system, signals received by vehicles in each V2I link and signals received by each V2V user;

determining an overall data rate in the internet of vehicles communication system from the data rate determined from the signals received by each V2V user and the signals received by the vehicles in each V2I link;

constructing an objective function by taking the maximum total data rate as an objective, configuring the power transmitted in the V2V link and the phase of each metamaterial radiation unit in the RIS as variables, and taking the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions;

the target power emitted in the V2V link and the target phase configuration of each metamaterial radiating element in the RIS are determined from the target function.

Optionally, the vehicle networking communication system comprises: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS.

Optionally, the determining, according to the objective function, the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS specifically includes:

and performing iterative optimization on the objective function until the difference between the objective functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

A vehicle networking communication optimization system based on a reconfigurable reflective super surface, comprising:

the Internet of vehicles communication system acquisition module is used for acquiring the Internet of vehicles communication system;

a signal determination module for determining signals received by vehicles in each V2I link and signals received by each V2V user according to the Internet of vehicles communication system;

a total data rate determination module for determining a total data rate in the internet of vehicles communication system based on the data rate determined from the signals received by each V2V user and the signals received by the vehicles in each V2I link;

the target function building module is used for building a target function by taking the maximum total data rate as a target, the power transmitted in the V2V link and the phase configuration of each metamaterial radiation unit in the RIS as variables and the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions;

and the scheme determining module is used for determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS according to the target function.

Optionally, the vehicle networking communication system comprises: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS.

Optionally, the scheme determining module specifically includes:

and the scheme determining unit is used for performing iterative optimization on the objective function until the difference between the objective functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the reconfigurable reflection super-surface-based vehicle networking communication optimization method and system provided by the invention have the advantages that the power transmitted in the V2V link and the phase configuration of each metamaterial radiation unit in the RIS are configured into variables to construct an objective function, the coupling relation between the power and the metamaterial radiation unit is fully considered, the method has universality and accords with an actual scene, and the V2V communication link and the V2I communication link are considered to have generality compared with the conventional vehicle networking communication with a single kind, the RIS interference is eliminated, the interference in the V2V communication is further reduced, the communication quality of V21 and V2V channels is effectively enhanced, and the influence caused by mutual interference of the two links is reduced. The overall data rate of the V2V communication system can be further improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is a schematic flow chart of a vehicle networking communication optimization method based on a reconfigurable reflection super surface, provided by the invention;

FIG. 2 is a schematic diagram of RIS based vehicle networking communications;

fig. 3 is a schematic structural diagram of a vehicle networking communication optimization system based on a reconfigurable reflection super surface provided by the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a vehicle networking communication optimization method and system based on a reconfigurable reflection super surface, which can improve the total data rate of a V2V communication system.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Fig. 1 is a schematic flow chart of a method for optimizing communication in a vehicle networking based on a reconfigurable reflective super surface, as shown in fig. 1, the method for optimizing communication in a vehicle networking based on a reconfigurable reflective super surface includes:

s101, acquiring a vehicle networking communication system; the car networking communication system includes: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS;

the RIS is a super-planar antenna and is formed by splicing a plurality of sub-wavelength reflecting units. The reflection coefficient of each reflection unit can be adjusted by applying different bias voltages, so that the reflection coefficient of the whole reflection surface can be controlled in a programming mode, the electromagnetic response (such as phase shift) of each RIS element can be controlled in a programming mode, and then an incident signal is reflected in the form of a directional beam, and finally the propagation environment is shaped into an ideal form.

The internet of vehicles means that vehicle-mounted equipment on a vehicle effectively utilizes all vehicle dynamic information in an information network platform through a wireless communication technology, and provides different functional services in the running process of the vehicle. The Internet of vehicles can provide guarantee for the distance between the vehicles, and the probability of collision accidents of the vehicles is reduced; the Internet of vehicles can help the vehicle owner to navigate in real time, and the efficiency of traffic operation is improved through communication with other vehicles and a network system.

S102, determining signals received by vehicles in each V2I link and signals received by each V2V user according to the Internet of vehicles communication system;

as a specific example, as shown in fig. 2, the car networking communication system includes 1 base station, one RIS for enhancing communication quality, K vehicles communicating with the base station V2I, the base station transmitting broadcast information to the vehicles, and L pairs of vehicles communicating with V2V. The vehicle transmitting the information in each V2V link is denoted t_lThe vehicle receiving the information is denoted as r_l。

Assuming that M metamaterial radiating elements are included on the RIS, each element changes the phase (frequency response factor) of the signal byThe transmission channel between each radiation unit of each RIS and each vehicle can be simulated by a computer according to the actual situation, t_lAnd r_lFor direct channel therebetweenDenotes, t_lChannel matrix to RISIs shown in whichThe dimension is mx 1. The signal sent by the base station to the vehicle k is s_kDirect channel h between base station and vehicle k_kIndicating, by g, the channel matrix from base station to RIS₀Is represented by the formula (I), wherein g₀Channel for vehicles with dimension M × 1, RIS to V2VIs shown in whichDimension 1 XM, channel matrix g for RIS to V2I vehicle_kIs represented by the formula (I), wherein g_kThe dimension of the glass is 1 multiplied by M,

in order to maximize the total communication data rate of all users in the vehicle networking communication system, the base station distributes power of the transmitting signals of all V2V links and then transmits the power, and for the V2I link, the base station transmits the broadcasting signals for each vehicle to each user through an RIS and a direct path.

Using formulasDetermining the signals received by each V2I vehicle in the Internet of vehicles communication system; wherein the second term is interference from a V2V user; z is a radical of_kIs the channel noise;

using formulasDetermining the signals received by each V2V user in the internet of vehicles communication system; wherein p is_iFor the transmit power of each V2V pair, the second term is the interference of the V2I vehicle, and the third term is the interference of the other V2V vehicles;is the channel noise;

s103, determining the total data rate in the internet of vehicles communication system according to the signals received by each V2V user and the data rate determined by the signals received by the vehicles in each V2I link;

according to the above embodiment, the data rates of the cellular users and the data rates of the V2V users are determined from the signals received by each V2V user and the signals received by the vehicles in each V2I link; determining the total data rate in the vehicle networking communication system according to the sum of the data rate of the cellular user and the data rate of the V2V user, specifically comprising the following formula:

s104, constructing an objective function by taking the maximum total data rate as an objective, the power transmitted in the V2V link and the phase configuration of each metamaterial radiation unit in the RIS as variables, and the total power of the transmitting end of the base station and the power threshold transmitted in the V2V link as constraint conditions;

the objective function is:

s.t.Tr(w^Hw)≤P_T，0≤p_i≤P_D；

wherein, P_TFor total power constraints at the transmitting end of the base station, P_DIs the power threshold transmitted in the V2V link.

S105, determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS according to the target function;

s105 specifically comprises the following steps:

and performing iterative optimization on the target function until the difference between the target functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

Fig. 3 is a schematic structural diagram of a car networking communication optimization system based on a reconfigurable reflection super surface, as shown in fig. 3, the car networking communication optimization system based on a reconfigurable reflection super surface provided by the present invention includes:

the internet of vehicles communication system acquisition module 301 is used for acquiring an internet of vehicles communication system; the car networking communication system includes: the system comprises a base station, a reconfigurable reflective super surface RIS, a V2I link, a V2V link, a plurality of vehicles in V2I communication with the base station and a plurality of pairs of vehicles in V2V communication; the V2I link includes: a direct base station to user link and a reflected transmission link through the RIS; the V2V link includes: a link between two vehicles and a reflective transmission link through the RIS;

a signal determination module 302 for determining signals received by vehicles in each V2I link and signals received by each V2V user according to an Internet of vehicles communication system;

a total data rate determination module 303, configured to determine a total data rate in the internet of vehicles communication system according to the data rate determined by the signal received by each V2V user and the signal received by the vehicle in each V2I link;

an objective function constructing module 304, configured to construct an objective function with the maximum total data rate as an objective, the power transmitted in the V2V link and the phase configuration of each metamaterial radiating element in the RIS as variables, and the total power at the transmitting end of the base station and the power threshold transmitted in the V2V link as constraints;

a scheme determination module 304 for determining a target power emitted in the V2V link and a target phase configuration of each metamaterial radiating element in the RIS according to the target function;

the scheme determination module 304 includes:

and the scheme determining unit is used for performing iterative optimization on the objective function until the difference between the objective functions of adjacent iterations is smaller than a set threshold value, and determining the target power transmitted in the V2V link and the target phase configuration of each metamaterial radiation unit in the RIS.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.