阅读说明：本技术 一种多ris场景下的通信选择方案 (Communication selection scheme under multi-RIS scene ) 是由 杨柳 孙焱燚 于 2021-06-09 设计创作，主要内容包括：本发明公开了一种多RIS场景下的通信选择方案,解决了目前对商用阶段RIS选择的技术、方案空白的弊端,其技术方案要点是当发射用户要与接收用户通信时,基站接收发射用户的位置信息及通信请求,并接收用户的位置信息以判断接收用户与发射用户的相对位置是否满足直接D2D的条件,若满足,则直接D2D通信；若不满足,对相对位置再一次进行判断是否满足RAD条件,若不满足,则直接使用蜂窝技术通信；反之基站各RIS距离收发用户距离的对应乘积,基站为用户分配带内频段的使用权限,借助乘积最小对应的RIS进行D2D通信辅助,本发明的一种多RIS场景下的通信选择方案,能在商用多个RIS场景下选择合适的RIS进行通信辅助,更加实用、高效。(The invention discloses a communication selection scheme under a multi-RIS scene, which solves the defects of the prior technology and scheme blank for commercial stage RIS selection, and the key points of the technical scheme are that when a transmitting user needs to communicate with a receiving user, a base station receives the position information and the communication request of the transmitting user and receives the position information of the user to judge whether the relative position of the receiving user and the transmitting user meets the condition of direct D2D, if so, the direct D2D communication is carried out; if not, judging whether the relative position meets RAD conditions again, and if not, directly using the cellular technology for communication; on the contrary, the base station distributes the use authority of the in-band frequency band for the user by the aid of the minimum product of the RIS distance corresponding to the user receiving and sending distance of each RIS, and the base station performs D2D communication assistance by the aid of the RIS corresponding to the minimum product.)

1. A communication selection scheme under a multi-RIS scene is characterized in that:

when a transmitting user S needs to communicate with a receiving user D, the transmitting user S sends own position information and a communication request to the receiving user D to a base station;

the base station receives the position information and the communication request of the transmitting user S and requires the receiving user D to send the position information of the base station, the base station receives the position information to judge whether the relative position of the receiving user D and the transmitting user S meets the condition of direct D2D, and if the relative position of the receiving user D and the transmitting user S meets the condition, direct D2D communication is carried out;

if the direct D2D condition is not met, judging whether the relative position meets the RAD condition again, and if not, directly using the cellular technology for communication;

if the RAD condition is met, the base station acquires the distance between each RIS and the transmitting user S and the distance between the RIS and the receiving user D and the corresponding product of the distances according to the position information of the RIS in the range, and selects the RIS corresponding to the minimum product result as the auxiliary equipment for RAD communication; the base station allocates the use authority of the in-band frequency band for the user, and the RIS-assisted D2D communication is carried out by means of the designated RIS.

2. A communication option under multiple RIS scenarios according to claim 1 wherein: the position set by each RIS is fixed, and the base station acquires the position information of the RIS within the range, transmits the position information of the user S and receives the position information of the user D;

setting N RISs with numbers of i-1, 2, …, N;

setting the distance d from the RIS with number i to the emitting user S_SiDistance D from receiving user D_iR，i＝1,2,…，N；

According to the inverse relation between the wireless channel gain of RIS auxiliary communication and the product of two cascade channel lengths, selecting the RIS with minimum product, i ═ argmin (d)_Si*d_iR)，i＝1,2,…，N。

3. A communication option under multiple RIS scenarios according to claim 2, characterized by: the communication range of the multi-RIS scene is a circular area, and the upper, lower, left and right vertexes of the circular area are respectively provided with a RIS.

4. A communication option under multiple RIS scenarios according to claim 3 wherein: a distance lower limit reference fixed value and a distance upper limit reference fixed value are set between the transmitting user S and the receiving user D;

when the distance between the transceiving users is smaller than the distance lower limit reference value, judging that the condition of direct D2D is met, and performing direct D2D communication;

when the distance between the transceiving users is larger than the distance upper limit reference fixed value or one of the transceiving users is not positioned in the set range, judging that the RAD condition is not met, and directly using the cellular technology for communication;

when the distance between the transceiving users is between the lower distance limit reference value and the upper distance limit reference value, the RIS assisted D2D communication is employed.

Technical Field

The invention relates to a wireless communication technology, in particular to a communication selection scheme under a multi-RIS scene.

Background

The current research of experts on RIS-assisted communication is only focused on a single RIS, such as the research of active and passive beamforming, channel estimation and information modulation. When the RIS enters the commercial stage, only one RIS can not be found in the range of a cell, the current research only focuses on the scene of a single RIS, ignores the possible RIS selection problem after commercial use, and has room for improvement.

Disclosure of Invention

The invention aims to provide a communication selection scheme under multiple RIS scenes, which can select a proper RIS to assist communication under multiple commercial RIS scenes and is more practical and efficient.

The technical purpose of the invention is realized by the following technical scheme:

a communication selection scheme under a multi-RIS scene is characterized in that when a transmitting user S needs to communicate with a receiving user D, the transmitting user S sends own position information and a communication request to the receiving user D to a base station;

the base station receives the position information and the communication request of the transmitting user S and requires the receiving user D to send the position information of the base station, the base station receives the position information to judge whether the relative position of the receiving user D and the transmitting user S meets the condition of direct D2D, and if the relative position of the receiving user D and the transmitting user S meets the condition, direct D2D communication is carried out;

if the direct D2D condition is not met, judging whether the relative position meets the RAD condition again, and if not, directly using the cellular technology for communication;

if the RAD condition is met, the base station acquires the distance between each RIS and the transmitting user S and the distance between the RIS and the receiving user D and the corresponding product of the distances according to the position information of the RIS in the range, and selects the RIS corresponding to the minimum product result as the auxiliary equipment for RAD communication; the base station allocates the use authority of the in-band frequency band for the user, and the RIS-assisted D2D communication is carried out by means of the designated RIS.

Preferably, the position set by each RIS is fixed, and the base station acquires the position information of the RIS within the range, the position information of the transmitting user S and the position information of the receiving user D;

setting N RISs with numbers of i-1, 2, …, N;

setting the distance d from the RIS with number i to the emitting user S_SiDistance D from receiving user D_iR，i＝1,2,…，N；

According to the inverse relation between the product of the wireless channel gain of the RIS auxiliary communication and the length of two cascade channels, the corresponding product with the minimum product is selectedRIS, i.e. i ═ argmin (d)_Si*d_iR)，i＝1,2,…，N。

Preferably, the multi-RIS scene communication range is a circular area, and one RIS is provided at each of four upper, lower, left, and right vertices of the circular area.

Preferably, a distance lower limit reference fixed value and a distance upper limit reference fixed value are set between the transmitting user S and the receiving user D;

when the distance between the transceiving users is smaller than the distance lower limit reference value, judging that the condition of direct D2D is met, and performing direct D2D communication;

when the distance between the transceiving users is larger than the distance upper limit reference fixed value or one of the transceiving users is not positioned in the set range, judging that the RAD condition is not met, and directly using the cellular technology for communication;

when the distance between the transceiving users is between the lower distance limit reference value and the upper distance limit reference value, the RIS assisted D2D communication is employed.

In conclusion, the invention has the following beneficial effects:

the communication can be optimized, efficient and convenient by selecting the corresponding communication mode according to the relative position relation of the receiving and sending users, and in the scene of multiple RISs, according to the inverse ratio relation between the product of the wireless channel gain of the RIS auxiliary communication and the length of two cascade channels, the RIS corresponding to the minimum distance product is selected as the auxiliary equipment, but the minimum product selection strategy in the environment with a larger base number can lead the D2D user to find the optimal RIS for communication assistance, thereby more optimally playing the role of the RIS in improving the spectrum efficiency and reducing the transmitting power;

the scheme can find the most suitable RIS for assistance so as to achieve the same receiving effect under the condition of ensuring the minimum transmitting power of the user, and reduce the influence caused by the inherent defects of the D2D communication.

Drawings

FIG. 1 is a schematic flow diagram of the protocol.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

In accordance with one or more embodiments, a communication option in a multiple RIS scenario is disclosed, as shown in fig. 1, comprising the steps of:

when the transmitting subscriber S wants to communicate with the receiving subscriber D, the transmitting subscriber S sends its own location information and a communication request to the receiving subscriber D to the base station.

The base station receives the position information and the communication request of the transmitting user S and requires the receiving user D to send the position information of the base station, the base station receives the position information to judge whether the relative position of the receiving user D and the transmitting user S meets the condition of direct D2D, and the condition of direct D2D is that the linear distance between the relative position of the receiving user D and the transmitting user S is smaller than a specified parameter; if so, direct D2D communication.

If the direct D2D condition is not met, judging whether the relative position meets the RAD condition again, wherein the RAD condition is that the distance between any two of the base station, the receiving user D and the transmitting user S is smaller than the set parameter; if not, the cellular technology is directly used for communication.

If the RAD condition is met, the base station acquires the distance between each RIS and the transmitting user S and the receiving user D and the corresponding product of the distances according to the position information of the RIS in the range. The communication range of the multi-RIS scene is a circular area, and the upper, lower, left and right vertexes of the circular area are respectively provided with a RIS.

Selecting the RIS corresponding to the minimum multiplication result as an auxiliary device for RAD communication according to the distance multiplication corresponding to each RIS; the base station allocates the use authority of the in-band frequency band for the user, and the RIS-assisted D2D communication is carried out by means of the designated RIS.

The position set by each RIS is fixed, the base station acquires the position information of the RIS within the range, transmits the position information of the user S and receives the position information of the user D, and the distance information can be obtained by conveniently calculating the position information;

setting N RISs with numbers of i-1, 2, …, N;

setting the distance d from the RIS with number i to the emitting user S_SiDistance D from receiving user D_iR，i＝1,2,…，N；

Wireless channel gain according to RIS assisted communicationIn inverse relation to the product of the lengths of the two concatenated channels, the RIS with the smallest product is selected, i.e. i is argmin (d)_Si*d_iR)，i＝1,2,…，N。

The base station appoints the RIS with the number i to serve the transmitting user S and the receiving user D, and distributes the use authority of the in-band frequency band. Therefore, the receiving and transmitting users can establish connection and the effect of multiplexing frequency bands is achieved.

Specifically, a distance lower limit reference fixed value and a distance upper limit reference fixed value are set between the transmitting user S and the receiving user D;

when the distance between the transceiving users is smaller than the distance lower limit reference value, judging that the condition of direct D2D is met, and performing direct D2D communication;

when the distance between the transceiving users is larger than the distance upper limit reference fixed value or one of the transceiving users is not positioned in a set range, and the general range is in a certain cell, judging that the RAD condition is not met, and directly using the cellular technology for communication;

when the distance between the transceiving users is between the lower distance limit reference value and the upper distance limit reference value, the RIS assisted D2D communication is employed.

The selection strategy with the minimum product is a research basis, the algorithm is superior to the selection strategy with the minimum addition, and although the two algorithms can select the same RIS in many cases, the selection strategy with the minimum product still has the advantages under the environment with a large base number. The transmit power of the D2D communication device cannot be too high, which would reduce the device standby time and battery life, and would interfere with the reception of other D2D users, even cellular users. By adopting the scheme, the most suitable RIS for assistance can be found so as to achieve the same receiving effect under the condition of ensuring the minimum transmitting power of the user, the influence caused by the inherent defects of D2D communication is reduced, the D2D user can find the optimal RIS for communication assistance, and the effects of the RIS on improving the spectrum efficiency and reducing the transmitting power are better exerted.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.