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CN113708819B - A Novel Reconfigurable Smart Surface-Based Non-Orthogonal Multiple Access Method - Google Patents

A Novel Reconfigurable Smart Surface-Based Non-Orthogonal Multiple Access Method Download PDF

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CN113708819B
CN113708819B CN202110972689.4A CN202110972689A CN113708819B CN 113708819 B CN113708819 B CN 113708819B CN 202110972689 A CN202110972689 A CN 202110972689A CN 113708819 B CN113708819 B CN 113708819B
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base station
smart surface
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CN113708819A (en
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盛彬
尤肖虎
黄永明
王东明
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Southeast University
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/14—Relay systems
    • H04B7/145—Passive relay systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/04013—Intelligent reflective surfaces
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference

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Abstract

The invention discloses a non-orthogonal multiple access method based on a novel reconfigurable intelligent surface, which comprises the following steps that a base station sends pilot frequency and controls the novel reconfigurable intelligent surface to sequentially open M units, and the reflection coefficient and the transmission coefficient of the novel reconfigurable intelligent surface are respectively set to be 1; based on the transmitted pilot, user A and user B calculate the channels reflected and transmitted by M units in turn
Figure DDA0003226465450000011
And
Figure DDA0003226465450000012
and will channel
Figure DDA0003226465450000013
And
Figure DDA0003226465450000014
feeding back to the base station; the base station compares the channels in turn
Figure DDA0003226465450000015
And
Figure DDA0003226465450000016
the size of the mold of (1), screening
Figure DDA0003226465450000017
And stores its corresponding unit as a setS; the base station closes the units outside the set S and sets the reflection coefficient and the transmission coefficient of the units in the set S to be respectively
Figure DDA0003226465450000018
And
Figure DDA0003226465450000019
user A and user B transmit signals separately
Figure DDA00032264654500000110
And
Figure DDA00032264654500000111
the base station will xB(n) as noise, demodulate xA(n); offset xAAfter (n), demodulate xB(n) of (a). The invention can construct a wireless channel environment suitable for NOMA transmission under the condition that the distance between the user and the base station is equal, effectively reduces the error rate of a receiving end and improves the system capacity.

Description

一种基于新型可重构智能表面的非正交多址接入方法A Novel Reconfigurable Smart Surface-Based Non-Orthogonal Multiple Access Method

技术领域technical field

本发明涉及移动通信系统的多址技术领域，尤其涉及一种基于新型可重构智能表面的非正交多址接入方法。The present invention relates to the technical field of multiple access of mobile communication systems, in particular to a non-orthogonal multiple access method based on a novel reconfigurable smart surface.

背景技术Background technique

近年来，随着第五代移动通信系统(5G)进入商用阶段，第六代移动通信系统(6G)的研发也拉开了序幕。6G将以全覆盖、全频谱、全应用、强安全的形式满足人们日益增长的各类通信需求，潜在的研究方向包括太赫兹通信，人工智能和超大规模MIMO技术等。In recent years, with the fifth-generation mobile communication system (5G) entering the commercial stage, the research and development of the sixth-generation mobile communication system (6G) has also kicked off. 6G will meet people's growing communication needs in the form of full coverage, full spectrum, full application and strong security. Potential research directions include terahertz communication, artificial intelligence and ultra-massive MIMO technology.

现代移动通信的发展揭示了无线信道的随机性和不确定性是影响无线传输质量的关键因素，发射机的无线电波在传输过程中与传输路径上各种物体不可控制的相互作用，导致接收端信号质量降低。可重构智能表面通过人为调整无线信道环境，显著提高了系统的传输性能，为未来无线通信的发展提供了新的思路。可重构智能表面由精心设计的电磁单元规则排列组成，这些电磁单元通常由金属、介质和可调元件构成。通过控制电磁单元中的可调元件，以可编程方式更改反射电磁波的电磁参数，例如相位和幅度。与传统中继通信相比，可重构智能表面可以工作在全双工模式下，具有更高的频谱利用率，且可重构智能表面无需射频(RF)链路，不需要大规模供电，在功耗和部署成本上都将具有优势。传统的可重构智能表面分为反射型智能表面和透射型智能表面，而新型的可重构智能表面在每个单元上可同时反射和透射无线信号。The development of modern mobile communication has revealed that the randomness and uncertainty of the wireless channel are the key factors affecting the quality of wireless transmission. Degraded signal quality. The reconfigurable smart surface significantly improves the transmission performance of the system by artificially adjusting the wireless channel environment, and provides a new idea for the development of future wireless communication. Reconfigurable smart surfaces consist of a regular arrangement of carefully designed electromagnetic cells, which are usually composed of metals, dielectrics, and tunable elements. By controlling the tunable elements in the electromagnetic unit, the electromagnetic parameters of the reflected electromagnetic wave, such as phase and amplitude, can be changed in a programmable way. Compared with traditional relay communication, the reconfigurable smart surface can work in full-duplex mode with higher spectrum utilization, and the reconfigurable smart surface does not require radio frequency (RF) links and does not require large-scale power supply. There will be advantages in both power consumption and deployment costs. Traditional reconfigurable smart surfaces are divided into reflective smart surfaces and transmissive smart surfaces, while new reconfigurable smart surfaces can simultaneously reflect and transmit wireless signals on each unit.

非正交多址接入技术也是一种能提高频谱效率的热点技术。目前该技术主要的四种方案分别为NOMA、MUSA、SCMA和PDMA。其中，NOMA是仅有功率域应用的非正交多址接入技术。其采用的是多个用户信号强度的线性叠加，硬件结构简单，技术性不高，基于串行干扰抵消(SIC)接收机也不复杂，是非正交多址接入技术中最简单的一种，易于与现有通信系统结合。但功率域用户层不宜太多，否则系统复杂性将徒然增加，系统性能将快速下降，所以通常只叠加2个用户。通常，NOMA需工作在用户与基站距离不相等的情况下，以便利用接收功率差进行SIC解调。因此，当不同用户与基站的距离相近时，几乎相等的功率导致误码率急速上升，使NOMA无法工作。Non-orthogonal multiple access technology is also a hot technology that can improve spectral efficiency. At present, the four main schemes of this technology are NOMA, MUSA, SCMA and PDMA. Among them, NOMA is a non-orthogonal multiple access technology only applied in the power domain. It adopts the linear superposition of the signal strength of multiple users, the hardware structure is simple, the technicality is not high, and the receiver based on serial interference cancellation (SIC) is not complicated. It is the simplest kind of non-orthogonal multiple access technology. Easy to integrate with existing communication systems. However, there should not be too many user layers in the power domain, otherwise the system complexity will increase in vain and the system performance will drop rapidly, so usually only two users are superimposed. Usually, NOMA needs to work under the condition that the distance between the user and the base station is unequal, so as to use the received power difference to perform SIC demodulation. Therefore, when the distances between different users and the base station are similar, the almost equal power causes the bit error rate to rise rapidly, making NOMA unable to work.

发明内容SUMMARY OF THE INVENTION

发明目的：为了克服现有技术中存在的不足，本发明提供一种基于新型可重构智能表面的非正交多址接入方法，该发明能够在用户与基站距离相等的情况下构造出适合NOMA传输的无线信道环境，有效降低了接收端的误码率，提高了系统容量。Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a non-orthogonal multiple access method based on a novel reconfigurable smart surface, which can construct a suitable The wireless channel environment of NOMA transmission effectively reduces the bit error rate of the receiving end and improves the system capacity.

技术方案：为了实现上述发明目的，本发明提供了一种基于新型可重构智能表面的非正交多址接入方法，包括以下步骤，Technical solution: In order to achieve the above purpose of the invention, the present invention provides a non-orthogonal multiple access method based on a novel reconfigurable smart surface, comprising the following steps:

步骤1，基站发送导频并控制新型可重构智能表面依次开启M个单元，同时将新型可重构智能表面的反射和透射系数分别设置为1；Step 1, the base station sends a pilot frequency and controls the new reconfigurable smart surface to turn on M units in sequence, and sets the reflection and transmission coefficients of the new reconfigurable smart surface to 1 respectively;

步骤2，根据发送的导频，依次计算用户A和用户B与基站间经过M个单元反射和透射的信道

Figure BDA0003226465430000021
和
Figure BDA0003226465430000022
并将信道
Figure BDA0003226465430000023
和
Figure BDA0003226465430000024
反馈至基站；Step 2, according to the sent pilot frequency, calculate the channel reflected and transmitted through M units between user A and user B and the base station in turn.
Figure BDA0003226465430000021
and
Figure BDA0003226465430000022
and channel
Figure BDA0003226465430000023
and
Figure BDA0003226465430000024
feedback to the base station;

步骤3，基站依次比较信道

Figure BDA0003226465430000025
和
Figure BDA0003226465430000026
的模的大小，筛选出
Figure BDA0003226465430000027
的单元序号，并将其对应单元存储为集合S；Step 3, the base station compares the channels in turn
Figure BDA0003226465430000025
and
Figure BDA0003226465430000026
the size of the modulo, filter out
Figure BDA0003226465430000027
the unit serial number of , and store its corresponding unit as a set S;

步骤4，基站将集合S以外的单元关闭，并将集合S中单元的反射和透射系数分别设置为

Figure BDA0003226465430000028
和
Figure BDA0003226465430000029
Step 4, the base station turns off the units other than the set S, and sets the reflection and transmission coefficients of the units in the set S to be
Figure BDA0003226465430000028
and
Figure BDA0003226465430000029

步骤5，用户A和用户B分别发送信号

Figure BDA00032264654300000210
和
Figure BDA00032264654300000211
至基站；Step 5: User A and User B send signals respectively
Figure BDA00032264654300000210
and
Figure BDA00032264654300000211
to the base station;

步骤6，基站将xB(n)作为噪声，解调xA(n)得到用户A接收信号

Figure BDA00032264654300000212
Step 6, the base station uses x B (n) as noise, and demodulates x A (n) to obtain the received signal of user A
Figure BDA00032264654300000212

步骤7，基站抵消xA(n)的干扰后，解调xB(n)得到用户B的接收信号

Figure BDA00032264654300000213
Step 7, after the base station cancels the interference of x A (n), demodulates x B (n) to obtain the received signal of user B
Figure BDA00032264654300000213

进一步的，在本发明中：所述步骤2中，用户A在第n个时刻接收到的离散基带等效信号

Figure BDA00032264654300000214
为：Further, in the present invention: in the step 2, the discrete baseband equivalent signal received by user A at the nth moment
Figure BDA00032264654300000214
for:

Figure BDA00032264654300000215
Figure BDA00032264654300000215

其中，

Figure BDA00032264654300000216
表示新型可重构智能表面第1个单元与用户A之间第n个时刻的信道，α1(n)为第1个单元在第n个时刻的反射系数，此处α1(n)＝1，
Figure BDA00032264654300000217
表示基站与新型可重构智能表面第1个单元之间第n个时刻的信道，xp(n)表示基站在第n个时刻发送的导频信号，wA(n)表示用户A第n个时刻的加性白高斯噪声；in,
Figure BDA00032264654300000216
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user A, α 1 (n) is the reflection coefficient of the first unit at the nth time, where α 1 (n)= 1,
Figure BDA00032264654300000217
represents the channel at the nth time between the base station and the first unit of the new reconfigurable smart surface, x p (n) represents the pilot signal sent by the base station at the nth time, and w A (n) represents the nth user A additive white Gaussian noise at a time;

由于α1(n)＝1，且接收端已知xp(n)，可以得到基站与用户A之间经过新型可重构智能表面反射的复合信道为：Since α 1 (n)=1, and x p (n) is known at the receiving end, the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface can be obtained as:

Figure BDA00032264654300000218
Figure BDA00032264654300000218

其中，

Figure BDA0003226465430000031
表示基站与用户A之间经过新型可重构智能表面反射的复合信道。in,
Figure BDA0003226465430000031
Represents the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface.

进一步的，在本发明中：所述步骤2中，经过新型可重构智能表面第1个单元的透射，用户B在第n个时刻接收到的离散基带等效信号

Figure BDA0003226465430000032
为：Further, in the present invention: in the step 2, through the transmission of the first unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B at the nth time
Figure BDA0003226465430000032
for:

Figure BDA0003226465430000033
Figure BDA0003226465430000033

其中，

Figure BDA0003226465430000034
表示新型可重构智能表面第1个单元与用户B之间第n个时刻的信道，β1(n)为第1个单元在第n个时刻的透射系数，此处β1(n)＝1，wB(n)表示用户B第n个时刻的加性白高斯噪声；in,
Figure BDA0003226465430000034
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user B, β 1 (n) is the transmission coefficient of the first unit at the nth time, where β 1 (n)= 1, w B (n) represents the additive white Gaussian noise of user B at the nth moment;

由于β1(n)＝1，且接收端已知xp(n)，可以得到基站与用户B之间经过新型可重构智能表面透射的复合信道为：Since β 1 (n)=1, and x p (n) is known at the receiving end, the composite channel transmitted by the new reconfigurable smart surface between the base station and user B can be obtained as:

Figure BDA0003226465430000035
Figure BDA0003226465430000035

其中，

Figure BDA0003226465430000036
表示基站与用户B之间经过新型可重构智能表面透射的复合信道。in,
Figure BDA0003226465430000036
Represents the composite channel transmitted between the base station and user B through the new reconfigurable smart surface.

进一步的，在本发明中：所述步骤2中，将新型可重构智能表面的反射和透射系数分别设置为1，在第n时刻，基站控制新型可重构智能表面打开第1个单元，并关闭其它单元，可以得到用户A接收到经过新型可重构智能表面第1个单元反射回来的离散基带等效信号

Figure BDA0003226465430000037
为：Further, in the present invention: in the step 2, the reflection and transmission coefficients of the new reconfigurable smart surface are set to 1 respectively, and at the nth moment, the base station controls the new reconfigurable smart surface to open the first unit, And turn off other units, user A can receive the discrete baseband equivalent signal reflected by the first unit of the new reconfigurable smart surface
Figure BDA0003226465430000037
for:

Figure BDA0003226465430000038
Figure BDA0003226465430000038

在接收端进行信道估计，并在所得结果中减去

Figure BDA0003226465430000039
即可得到基站与用户A之间经过新型可重构智能表面反射的复合信道。Channel estimation is performed at the receiver and subtracted from the result
Figure BDA0003226465430000039
The composite channel between the base station and the user A reflected by the new reconfigurable smart surface can be obtained.

进一步的，在本发明中：所述步骤2中，在第n+1时刻，基站控制新型可重构智能表面打开第2个单元，并关闭其它单元，此时用户A接收到经过新型可重构智能表面第2个单元反射回来的离散基带等效信号

Figure BDA00032264654300000310
为：Further, in the present invention: in the step 2, at the n+1th time, the base station controls the new reconfigurable smart surface to open the second unit and close other units. The discrete baseband equivalent signal reflected from the second unit of the smart surface
Figure BDA00032264654300000310
for:

Figure BDA00032264654300000311
Figure BDA00032264654300000311

其中，

Figure BDA00032264654300000312
表示新型可重构智能表面第2个单元与用户A之间的信道，α2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且α2(n+1)＝1，
Figure BDA00032264654300000313
表示基站与新型可重构智能表面第2个单元之间第n+1个时刻的信道，xp(n+1)表示基站在第n+1个时刻发送的导频信号，wA(n+1)表示用户A第n+1个时刻的加性白高斯噪声。in,
Figure BDA00032264654300000312
represents the channel between the second unit of the new reconfigurable smart surface and user A, α 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and α 2 (n+1)=1,
Figure BDA00032264654300000313
represents the channel at the n+1th time between the base station and the second unit of the new reconfigurable smart surface, x p (n+1) represents the pilot signal sent by the base station at the n+1th time, w A (n +1) represents the additive white Gaussian noise at the n+1th moment of user A.

进一步的，在本发明中：所述步骤2中，由于α2(n+1)＝1，且接收端已知xp(n)，可得到基站与用户A之间经过新型可重构智能表面反射的复合信道

Figure BDA00032264654300000314
为：Further, in the present invention: in the step 2, since α 2 (n+1)=1, and x p (n) is known at the receiving end, it can be obtained that a new type of reconfigurable intelligence is passed between the base station and the user A. Surface-reflected composite channel
Figure BDA00032264654300000314
for:

Figure BDA0003226465430000041
Figure BDA0003226465430000041

进一步的，在本发明中：所述步骤2中，经过新型可重构智能表面第2个单元的透射，用户B接收到的离散基带等效信号

Figure BDA0003226465430000042
为：Further, in the present invention: in the step 2, through the transmission of the second unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B
Figure BDA0003226465430000042
for:

Figure BDA0003226465430000043
Figure BDA0003226465430000043

其中，

Figure BDA0003226465430000044
表示新型可重构智能表面第2个单元与用户B之间的信道，β2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且β2(n+1)＝1，wB(n+1)表示用户B第n+1个时刻的加性白高斯噪声。in,
Figure BDA0003226465430000044
represents the channel between the second unit of the new reconfigurable smart surface and user B, β 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and β 2 (n+1)=1, w B (n+1) represents the additive white Gaussian noise of user B at the n+1 th time.

进一步的，在本发明中：所述步骤2中，由于β2(n+1)＝1，且接收端已知xp(n)，可得到基站与用户B之间经过新型可重构智能表面透射的复合信道

Figure BDA0003226465430000045
为：Further, in the present invention: in the step 2, since β 2 (n+1)=1, and x p (n) is known at the receiving end, it can be obtained that a new type of reconfigurable intelligence is passed between the base station and user B. Surface Transmissive Composite Channel
Figure BDA0003226465430000045
for:

Figure BDA0003226465430000046
Figure BDA0003226465430000046

进一步的，在本发明中：所述步骤6还包括，假设用户与基站之间的直接信道被阻挡，基站在第n个时刻接收到的离散基带等效信号rBS(n)为：Further, in the present invention: the step 6 further includes, assuming that the direct channel between the user and the base station is blocked, the discrete baseband equivalent signal r BS (n) received by the base station at the nth moment is:

Figure BDA0003226465430000047
Figure BDA0003226465430000047

进一步的，由于用户A的信道条件较好，基站会先将用户B的信号xB(n)作为噪声，解调用户A的信号xA(n)，得到解调后的用户A接收信号

Figure BDA0003226465430000048
Further, since the channel condition of user A is better, the base station will first use the signal x B (n) of user B as noise, demodulate the signal x A (n) of user A, and obtain the demodulated signal received by user A.
Figure BDA0003226465430000048

Figure BDA0003226465430000049
Figure BDA0003226465430000049

进一步的，在本发明中：所述步骤7还包括，基于SIC技术，基站先抵消用户A产生的干扰后，再解调用户B的数据，即：Further, in the present invention: the step 7 also includes, based on the SIC technology, the base station first cancels the interference generated by the user A, and then demodulates the data of the user B, namely:

Figure BDA00032264654300000410
Figure BDA00032264654300000410

其中，yB(n)表示抵消干扰后的用户B的接收信号，

Figure BDA00032264654300000411
表示
Figure BDA00032264654300000412
经过硬判或软判后重新生成的符号，最终得到用户B的接收信号
Figure BDA00032264654300000413
为：where y B (n) represents the received signal of user B after interference cancellation,
Figure BDA00032264654300000411
express
Figure BDA00032264654300000412
The symbol regenerated after hard or soft judgment, and finally the received signal of user B is obtained
Figure BDA00032264654300000413
for:

Figure BDA00032264654300000414
Figure BDA00032264654300000414

有益效果：本发明与现有技术相比，其有益效果是：本发明将可重构智能表面和NOMA技术结合，提出了一种新型的无线通信方案，该方案通过对可同时反射和透射的新型可重构智能表面上的反射和透射单元进行选择，在两个用户各自与基站之间的距离相近或相等的特殊情况下，构造出适合NOMA传输的无线信道环境，有效降低了接收端的误码率，提高了系统容量，且计算复杂度低，不需要增加任何额外的器件；除了可同时反射和透射的新型可重构智能表面，本发明的单元选择方法还能够适用于其它种类的可重构智能表面，包括只反射的可重构智能表面、带有部分射频链路(RF)的混合可重构智能表面等。Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: the present invention combines the reconfigurable smart surface and NOMA technology, and proposes a new wireless communication scheme. The reflection and transmission units on the new reconfigurable smart surface are selected to construct a wireless channel environment suitable for NOMA transmission in the special case that the distances between the two users and the base station are similar or equal, which effectively reduces the error of the receiving end. The code rate increases the system capacity, and the computational complexity is low, and no additional devices need to be added; in addition to the new reconfigurable smart surface that can reflect and transmit at the same time, the cell selection method of the present invention can also be applied to other types of Reconfigurable smart surfaces, including reflection-only reconfigurable smart surfaces, hybrid reconfigurable smart surfaces with partial radio frequency links (RF), and more.

附图说明Description of drawings

图1为本发明提出的基于新型可重构智能表面的非正交多址接入方法的整体流程示意图；1 is a schematic overall flow diagram of a non-orthogonal multiple access method based on a novel reconfigurable smart surface proposed by the present invention;

图2为本发明中新型可重构智能表面的NOMA原理示意图；Fig. 2 is the NOMA principle schematic diagram of the novel reconfigurable smart surface in the present invention;

图3为分别基于传统方法和本发明提出方法下仿真得到的误码率对比图。FIG. 3 is a comparison diagram of bit error rates obtained by simulation based on the traditional method and the method proposed by the present invention respectively.

具体实施方式Detailed ways

下面结合附图对本发明的技术方案做进一步的详细说明：Below in conjunction with accompanying drawing, the technical scheme of the present invention is described in further detail:

本发明可以用许多不同的形式实现，而不应当认为限于这里所述的实施例。相反，提供这些实施例以便使本公开透彻且完整，并且将向本领域技术人员充分表达本发明的范围。The present invention may be embodied in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

如图1所示，图1为本发明所述的一种基于新型可重构智能表面的非正交多址接入方法的整体流程示意图，该方法包括以下步骤，As shown in FIG. 1, FIG. 1 is a schematic overall flow diagram of a non-orthogonal multiple access method based on a novel reconfigurable smart surface according to the present invention, and the method includes the following steps:

构建一个新型可重构智能表面辅助的上行窄带通信系统，该系统的基站包括一根天线，新型可重构智能表面包括M个单元，其中每个单元可同时反射和透射基站发送的信号，且第m个单元的反射系数为αm，透射系数为βm，m＝1,2，...,M。由于每个单元都是无源的被动反射元件，因此反射系数和透射系数分别满足0≤|αm|≤1，0≤|αm|≤1。Construct a novel reconfigurable smart surface-assisted uplink narrowband communication system, the base station of the system includes an antenna, the new reconfigurable smart surface includes M units, each of which can simultaneously reflect and transmit the signal sent by the base station, and The reflection coefficient of the mth element is α m , the transmission coefficient is β m , m=1,2,...,M. Since each unit is a passive passive reflection element, the reflection coefficient and transmission coefficient satisfy 0≤|α m |≤1, 0≤|α m |≤1, respectively.

具体的，参照图2的示意，在本发明中用户A和用户B均只有1根天线用于接收反射信号，且用户位于新型可重构智能表面的前面，即位于反射区，用户A能够接收经过新型可重构智能表面反射的信号；用户B有1根天线，且用户位于新型可重构智能表面的后面，即位于透射区，用户B能够接收经过新型可重构智能表面透射的信号。由于用户可以同时位于新型可重构智能表面的前后两侧，相比于传统只能反射信号的新型可重构智能表面，新型可重构智能表面扩大了覆盖范围。Specifically, referring to the schematic diagram of FIG. 2 , in the present invention, both user A and user B have only one antenna for receiving the reflected signal, and the user is located in front of the new reconfigurable smart surface, that is, in the reflection area, and user A can receive the reflected signal. The signal reflected by the new reconfigurable smart surface; user B has one antenna, and the user is located behind the new reconfigurable smart surface, that is, in the transmission area, user B can receive the signal transmitted by the new reconfigurable smart surface. Since users can be on both the front and the back of the new reconfigurable smart surface, the new reconfigurable smart surface has expanded coverage compared to traditional new reconfigurable smart surfaces that only reflect signals.

步骤1，基站发送导频并控制新型可重构智能表面依次开启M个单元，同时将新型可重构智能表面的反射和透射系数分别设置为1；其中，开启时单元时每次只开启1个单元。Step 1, the base station sends a pilot frequency and controls the new reconfigurable smart surface to turn on M units in turn, and at the same time sets the reflection and transmission coefficients of the new reconfigurable smart surface to 1 respectively; wherein, when the unit is turned on, only 1 is turned on each time. unit.

假设基站与用户A之间的直接信道被障碍物遮挡，只存在基站经过新型可重构智能表面反射到达用户A的反射信道，并且由于用户B位于新型可重构智能表面的后面，通常只存在基站经过新型可重构智能表面到达用户B的透射信道。经过频率平坦性衰落信道，用户A在第n个时刻接收到的离散基带等效信号

Figure BDA0003226465430000061
为：Assuming that the direct channel between the base station and user A is blocked by obstacles, there is only a reflection channel from the base station to user A through the new reconfigurable smart surface. The base station reaches the transmission channel of user B through the new reconfigurable smart surface. After the frequency flat fading channel, the discrete baseband equivalent signal received by user A at the nth time
Figure BDA0003226465430000061
for:

Figure BDA0003226465430000062
Figure BDA0003226465430000062

其中，

Figure BDA0003226465430000063
表示新型可重构智能表面第1个单元与用户A之间第n个时刻的信道，α1(n)为第1个单元在第n个时刻的反射系数，此处α1(n)＝1，
Figure BDA0003226465430000064
表示基站与新型可重构智能表面第1个单元之间第n个时刻的信道，xp(n)表示基站在第n个时刻发送的导频信号，wA(n)表示用户A第n个时刻的加性白高斯噪声。in,
Figure BDA0003226465430000063
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user A, α 1 (n) is the reflection coefficient of the first unit at the nth time, where α 1 (n)= 1,
Figure BDA0003226465430000064
represents the channel at the nth time between the base station and the first unit of the new reconfigurable smart surface, x p (n) represents the pilot signal sent by the base station at the nth time, and w A (n) represents the nth user A additive white Gaussian noise at a time.

假设信道相干时间远大于信道估计和数据传输时间，可认为信道在传输期间保持不变，即信道与时间n无关，因此为了简化表示，在下面的分析中可省略有关信道的时间序号n。由于α1(n)＝1，且接收端已知xp(n)，可以得到基站与用户A之间经过新型可重构智能表面反射的复合信道为：Assuming that the channel coherence time is much longer than the channel estimation and data transmission time, it can be considered that the channel remains unchanged during transmission, that is, the channel has nothing to do with time n. Therefore, in order to simplify the representation, the time sequence number n of the relevant channel can be omitted in the following analysis. Since α 1 (n)=1, and x p (n) is known at the receiving end, the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface can be obtained as:

Figure BDA0003226465430000065
Figure BDA0003226465430000065

其中，

Figure BDA0003226465430000066
表示基站与用户A之间经过新型可重构智能表面反射的复合信道。in,
Figure BDA0003226465430000066
Represents the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface.

同时，经过新型可重构智能表面第1个单元的透射，用户B在第n个时刻接收到的离散基带等效信号

Figure BDA0003226465430000067
为：At the same time, through the transmission of the first unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B at the nth time
Figure BDA0003226465430000067
for:

Figure BDA0003226465430000068
Figure BDA0003226465430000068

其中，

Figure BDA0003226465430000069
表示新型可重构智能表面第1个单元与用户B之间第n个时刻的信道，β1(n)为第1个单元在第n个时刻的透射系数，此处β1(n)＝1，wB(n)表示用户B第n个时刻的加性白高斯噪声。in,
Figure BDA0003226465430000069
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user B, β 1 (n) is the transmission coefficient of the first unit at the nth time, where β 1 (n)= 1, w B (n) represents the additive white Gaussian noise of user B at the nth time.

由于β1(n)＝1，且接收端已知xp(n)，可以得到基站与用户B之间经过新型可重构智能表面透射的复合信道为：Since β 1 (n)=1, and x p (n) is known at the receiving end, the composite channel transmitted by the new reconfigurable smart surface between the base station and user B can be obtained as:

Figure BDA00032264654300000610
Figure BDA00032264654300000610

其中，

Figure BDA00032264654300000611
表示基站与用户B之间经过新型可重构智能表面透射的复合信道。in,
Figure BDA00032264654300000611
Represents the composite channel transmitted between the base station and user B through the new reconfigurable smart surface.

进一步的，若基站与用户A之间的直接信道未被遮挡，则先关闭新型可重构智能表面上的所有单元，并估计该直接信道，得到：Further, if the direct channel between the base station and user A is not blocked, all units on the new reconfigurable smart surface are closed first, and the direct channel is estimated to obtain:

rBU(n)＝hBUxp(n)+wBU(n)r BU (n)=h BU x p (n)+w BU (n)

其中，rBU(n)表示通过用户A与基站之间的直接信道收到的信号，hBU表示基站与用户A之间的直接信道，wBU(n)表示直接信道的加性白高斯噪声。where r BU (n) represents the signal received through the direct channel between user A and the base station, h BU represents the direct channel between the base station and user A, and w BU (n) represents the additive white Gaussian noise of the direct channel .

由于接收端已知xp(n)，可得到该直接信道的估计值为：Since x p (n) is known at the receiving end, the estimated value of the direct channel can be obtained as:

Figure BDA0003226465430000071
Figure BDA0003226465430000071

其中，

Figure BDA0003226465430000072
为直接信道的估计值。in,
Figure BDA0003226465430000072
is the estimated value of the direct channel.

进一步的，将新型可重构智能表面的反射和透射系数分别设置为1，在第n时刻，基站控制新型可重构智能表面打开第1个单元，并关闭其它单元，可以得到用户A接收到经过新型可重构智能表面第1个单元反射回来的离散基带等效信号

Figure BDA0003226465430000073
为：Further, the reflection and transmission coefficients of the new reconfigurable smart surface are set to 1 respectively. At the nth moment, the base station controls the new reconfigurable smart surface to turn on the first unit and turn off other units. User A can receive Discrete baseband equivalent signal reflected from the first unit of the new reconfigurable smart surface
Figure BDA0003226465430000073
for:

Figure BDA0003226465430000074
Figure BDA0003226465430000074

在接收端进行信道估计，并在所得结果中减去

Figure BDA0003226465430000075
即可得到基站与用户A之间经过新型可重构智能表面反射的复合信道。Channel estimation is performed at the receiver and subtracted from the result
Figure BDA0003226465430000075
The composite channel between the base station and the user A reflected by the new reconfigurable smart surface can be obtained.

进一步的，在第n+1时刻，基站控制新型可重构智能表面打开第2个单元，并关闭其它单元，此时用户A接收到经过新型可重构智能表面第2个单元反射回来的离散基带等效信号

Figure BDA0003226465430000076
为：Further, at the n+1th moment, the base station controls the new reconfigurable smart surface to turn on the second unit and turn off other units. At this time, user A receives the discrete reflected back through the second unit of the new reconfigurable smart surface. Baseband Equivalent Signal
Figure BDA0003226465430000076
for:

Figure BDA0003226465430000077
Figure BDA0003226465430000077

其中，

Figure BDA0003226465430000078
表示新型可重构智能表面第2个单元与用户A之间的信道，α2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且α2(n+1)＝1，
Figure BDA0003226465430000079
表示基站与新型可重构智能表面第2个单元之间第n+1个时刻的信道，xp(n+1)表示基站在第n+1个时刻发送的导频信号，wA(n+1)表示用户A第n+1个时刻的加性白高斯噪声。in,
Figure BDA0003226465430000078
represents the channel between the second unit of the new reconfigurable smart surface and user A, α 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and α 2 (n+1)=1,
Figure BDA0003226465430000079
represents the channel at the n+1th time between the base station and the second unit of the new reconfigurable smart surface, x p (n+1) represents the pilot signal sent by the base station at the n+1th time, w A (n +1) represents the additive white Gaussian noise at the n+1th moment of user A.

由于α2(n+1)＝1，且接收端已知xp(n+1)，可得到基站与用户A之间经过新型可重构智能表面反射的复合信道

Figure BDA00032264654300000710
为：Since α 2 (n+1)=1, and x p (n+1) is known at the receiving end, the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface can be obtained
Figure BDA00032264654300000710
for:

Figure BDA00032264654300000711
Figure BDA00032264654300000711

同时，经过新型可重构智能表面第2个单元的透射，用户B接收到的离散基带等效信号

Figure BDA0003226465430000081
为：At the same time, through the transmission of the second unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B
Figure BDA0003226465430000081
for:

Figure BDA0003226465430000082
Figure BDA0003226465430000082

其中，

Figure BDA0003226465430000083
表示新型可重构智能表面第2个单元与用户B之间的信道，β2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且β2(n+1)＝1，wB(n+1)表示用户B第n+1个时刻的加性白高斯噪声。in,
Figure BDA0003226465430000083
represents the channel between the second unit of the new reconfigurable smart surface and user B, β 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and β 2 (n+1)=1, w B (n+1) represents the additive white Gaussian noise of user B at the n+1 th time.

由于β2(n+1)＝1，且接收端已知xp(n)，可得到基站与用户B之间经过新型可重构智能表面透射的复合信道

Figure BDA0003226465430000084
为：Since β 2 (n+1)=1, and x p (n) is known at the receiving end, the composite channel transmitted between the base station and user B through the new reconfigurable smart surface can be obtained
Figure BDA0003226465430000084
for:

Figure BDA0003226465430000085
Figure BDA0003226465430000085

步骤2，根据发送的导频，依次计算用户A和用户B与基站间经过M个单元反射和透射的信道

Figure BDA0003226465430000086
和
Figure BDA0003226465430000087
并将信道
Figure BDA0003226465430000088
和
Figure BDA0003226465430000089
反馈至基站；Step 2, according to the sent pilot frequency, calculate the channel reflected and transmitted through M units between user A and user B and the base station in turn.
Figure BDA0003226465430000086
and
Figure BDA0003226465430000087
and channel
Figure BDA0003226465430000088
and
Figure BDA0003226465430000089
feedback to the base station;

具体的，基于步骤1中的方法，接收端最终可以得到基站与用户A之间经过新型可重构智能表面所有单元反射的复合信道估计

Figure BDA00032264654300000810
以及经过新型可重构智能表面所有单元透射的复合信道估计
Figure BDA00032264654300000811
且m＝1,2,...,M。接收端将获取到的
Figure BDA00032264654300000812
和
Figure BDA00032264654300000813
全部反馈至基站。Specifically, based on the method in step 1, the receiving end can finally obtain a composite channel estimate between the base station and user A that is reflected by all elements of the new reconfigurable smart surface
Figure BDA00032264654300000810
and composite channel estimates transmitted through all elements of the new reconfigurable smart surface
Figure BDA00032264654300000811
and m=1,2,...,M. The receiver will get
Figure BDA00032264654300000812
and
Figure BDA00032264654300000813
All feedback to the base station.

步骤3，基站依次比较信道

Figure BDA00032264654300000814
和
Figure BDA00032264654300000815
的模的大小，筛选出
Figure BDA00032264654300000816
的单元序号，并将其对应单元存储为集合S；Step 3, the base station compares the channels in turn
Figure BDA00032264654300000814
and
Figure BDA00032264654300000815
the size of the modulo, filter out
Figure BDA00032264654300000816
the unit serial number of , and store its corresponding unit as a set S;

具体的，基站从开始m＝1开始，依次比较相同单元下

Figure BDA00032264654300000817
和
Figure BDA00032264654300000818
的模的大小，并筛选出
Figure BDA00032264654300000819
时对应的单元序号，将
Figure BDA00032264654300000820
时应的单元序号存储为集合S。例如，若
Figure BDA00032264654300000821
则S＝{1,2,8}。Specifically, the base station starts from m=1, and compares the same units in turn.
Figure BDA00032264654300000817
and
Figure BDA00032264654300000818
the size of the modulo, and filter out
Figure BDA00032264654300000819
When the corresponding unit serial number, the
Figure BDA00032264654300000820
The corresponding unit serial number is stored as set S. For example, if
Figure BDA00032264654300000821
Then S={1,2,8}.

步骤4，进行数据传输，此时基站将集合S以外的单元关闭，并将集合S中单元的反射和透射系数分别设置为

Figure BDA00032264654300000822
和
Figure BDA00032264654300000823
其中m∈S；Step 4: Perform data transmission. At this time, the base station closes the units other than the set S, and sets the reflection and transmission coefficients of the units in the set S to be
Figure BDA00032264654300000822
and
Figure BDA00032264654300000823
where m∈S;

具体的，将集合S之外的单元均关闭，集合S中序号对应的单元保持开启，并将这些单元的反射系数αm和透射系数βm分别设置为：Specifically, all units other than the set S are turned off, the units corresponding to the serial numbers in the set S are kept on, and the reflection coefficient α m and transmission coefficient β m of these units are respectively set as:

Figure BDA00032264654300000824
Figure BDA00032264654300000824

Figure BDA00032264654300000825
Figure BDA00032264654300000825

其中，angle(·)表示取相角操作，j表示虚数单位。Among them, angle(·) represents the operation of taking the phase angle, and j represents the imaginary unit.

步骤5，用户A和用户B分别向基站发送信号

Figure BDA00032264654300000826
和
Figure BDA00032264654300000827
Step 5: User A and User B send signals to the base station respectively
Figure BDA00032264654300000826
and
Figure BDA00032264654300000827

由于反射系数和透射系数在数据传输阶段保持不变，因此αm和βm可以忽略时间序号n。用户A和用户B在第n个时刻分别发送信号

Figure BDA00032264654300000828
和
Figure BDA00032264654300000829
其中，PA和PB分别表示用户A和用户B的发送功率，且PA＝PB。Since the reflection coefficient and transmission coefficient remain unchanged in the data transmission stage, α m and β m can ignore the time sequence number n. User A and User B respectively send signals at the nth time
Figure BDA00032264654300000828
and
Figure BDA00032264654300000829
Among them, P A and P B represent the transmit power of user A and user B, respectively, and P A =P B .

步骤6，基站将xB(n)作为噪声，解调xA(n)得到用户A接收信号

Figure BDA0003226465430000091
Step 6, the base station uses x B (n) as noise, and demodulates x A (n) to obtain the received signal of user A
Figure BDA0003226465430000091

假设用户与基站之间的直接信道被阻挡，基站在第n个时刻接收到的离散基带等效信号rBS(n)为：Assuming that the direct channel between the user and the base station is blocked, the discrete baseband equivalent signal r BS (n) received by the base station at the nth moment is:

Figure BDA0003226465430000092
Figure BDA0003226465430000092

进一步的，由于在集合S中

Figure BDA0003226465430000093
的模大于
Figure BDA0003226465430000094
的模，因此用户A的信道条件较好，基站会先将用户B的信号xB(n)作为噪声，解调用户A的信号xA(n)，得到解调后的用户A接收信号
Figure BDA0003226465430000095
Further, since in the set S
Figure BDA0003226465430000093
The modulus is greater than
Figure BDA0003226465430000094
Therefore, the channel condition of user A is better. The base station will first use the signal x B (n) of user B as noise, demodulate the signal x A (n) of user A, and obtain the demodulated signal received by user A.
Figure BDA0003226465430000095

Figure BDA0003226465430000096
Figure BDA0003226465430000096

步骤7，基站抵消xA(n)的干扰后，解调xB(n)得到用户B的接收信号

Figure BDA0003226465430000097
Step 7, after the base station cancels the interference of x A (n), demodulates x B (n) to obtain the received signal of user B
Figure BDA0003226465430000097

具体的，采用SIC技术，基站先抵消用户A产生的干扰后，再解调用户B的数据，即：Specifically, using the SIC technology, the base station first cancels the interference generated by user A, and then demodulates the data of user B, that is:

Figure BDA0003226465430000098
Figure BDA0003226465430000098

其中，yB(n)表示抵消干扰后的用户B的接收信号，

Figure BDA0003226465430000099
表示
Figure BDA00032264654300000910
经过硬判或软判后重新生成的符号，最终得到用户B的接收信号
Figure BDA00032264654300000911
为：where y B (n) represents the received signal of user B after interference cancellation,
Figure BDA0003226465430000099
express
Figure BDA00032264654300000910
The symbol regenerated after hard or soft judgment, and finally the received signal of user B is obtained
Figure BDA00032264654300000911
for:

Figure BDA00032264654300000912
Figure BDA00032264654300000912

为了验证本发明的有益效果，进行如下的仿真实验：构建的新型可重构智能表面包括128个单元，每个单元可同时反射和透射信号，基站距离新型RIS为50米。用户A和用户B分别与新型可重构智能表面距离50米，用户A和用户B的信号发送功率同为30dBm，即：PA＝PB＝1mW。In order to verify the beneficial effects of the present invention, the following simulation experiments are carried out: the constructed new reconfigurable smart surface includes 128 units, each unit can reflect and transmit signals at the same time, and the base station is 50 meters away from the new RIS. User A and User B are respectively 50 meters away from the new reconfigurable smart surface, and the signal transmission powers of User A and User B are both 30 dBm, namely: P A =P B =1 mW.

假设基站与用户之间直接信道被阻挡，即不存在直接信道，基站与新型可重构智能表面之间以及新型可重构智能表面与用户之间是莱斯信道，莱斯因子为10，路径衰落指数PLE为2.2。参考距离为1米，在参考距离处的路径损耗为-30dB。用户A和B在相同的时频资源上发送QPSK信号，基站统计所有接收数据的误码率。在传统方法下，由于用户A和B距离新型可重构智能表面距离相等，信号的接收功率相近，采用全部单元反射和透射的传统方法误码率较高，几乎无法工作。Assuming that the direct channel between the base station and the user is blocked, that is, there is no direct channel, there are Rice channels between the base station and the new reconfigurable smart surface and between the new reconfigurable smart surface and the user, the Rice factor is 10, and the path The fade index PLE is 2.2. The reference distance is 1 meter and the path loss at the reference distance is -30dB. Users A and B send QPSK signals on the same time-frequency resource, and the base station counts the bit error rates of all received data. Under the traditional method, since users A and B are at the same distance from the new reconfigurable smart surface and the received power of the signal is similar, the traditional method using all unit reflection and transmission has a high bit error rate and can hardly work.

而基于本发明提出的基于新型可重构智能表面的非正交多址接入方法，通过对单元的选择，使用户A的信道优于用户B的信道，构造出适合NOMA的传播环境，随着噪声方差减小，极大地降低了误码率，保证了传输的可靠性。参照图3的示意，为分别基于传统方法和本发明提出方法下仿真得到的误码率(BER)对比示意图。On the other hand, based on the non-orthogonal multiple access method based on the novel reconfigurable smart surface proposed by the present invention, through the selection of units, the channel of user A is better than the channel of user B, and a propagation environment suitable for NOMA is constructed. The noise variance is reduced, which greatly reduces the bit error rate and ensures the reliability of transmission. Referring to the schematic diagram of FIG. 3 , it is a schematic diagram of comparing bit error rates (BER) obtained by simulation based on the traditional method and the method proposed by the present invention respectively.

应说明的是，以上所述实施例仅表达了本发明的部分实施方式，其描述并不能理解为对本发明专利范围的限制。应当指出的是，对于本技术领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干改进，这些均应落入本发明的保护范围。It should be noted that the above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof should not be construed as limiting the patent scope of the present invention. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, several improvements can be made, which should fall within the protection scope of the present invention.

Claims (3)

1.一种基于新型可重构智能表面的非正交多址接入方法，其特征在于：包括以下步骤，1. a non-orthogonal multiple access method based on novel reconfigurable intelligent surface, is characterized in that: comprise the following steps, 步骤1，基站发送导频并控制新型可重构智能表面依次开启M个单元，同时将新型可重构智能表面的反射和透射系数分别设置为1；Step 1, the base station sends a pilot frequency and controls the new reconfigurable smart surface to turn on M units in sequence, and sets the reflection and transmission coefficients of the new reconfigurable smart surface to 1 respectively; 步骤2，根据发送的导频，依次计算用户A和用户B与基站间经过M个单元反射和透射的信道
Figure FDA0003637924340000011
和
Figure FDA0003637924340000012
并将信道
Figure FDA0003637924340000013
和
Figure FDA0003637924340000014
反馈至基站；Step 2, according to the sent pilot frequency, calculate the channel reflected and transmitted through M units between user A and user B and the base station in turn.
Figure FDA0003637924340000011
and
Figure FDA0003637924340000012
and channel
Figure FDA0003637924340000013
and
Figure FDA0003637924340000014
feedback to the base station; 所述步骤2中，用户A在第n个时刻接收到的离散基带等效信号
Figure FDA0003637924340000015
为：In the step 2, the discrete baseband equivalent signal received by user A at the nth time
Figure FDA0003637924340000015
for:
Figure FDA0003637924340000016
Figure FDA0003637924340000016
 其中，
Figure FDA0003637924340000017
表示新型可重构智能表面第1个单元与用户A之间第n个时刻的信道，α1(n)为第1个单元在第n个时刻的反射系数，此处α1(n)＝1，
Figure FDA0003637924340000018
表示基站与新型可重构智能表面第1个单元之间第n个时刻的信道，xp(n)表示基站在第n个时刻发送的导频信号，wA(n)表示用户A第n个时刻的加性白高斯噪声；in,
Figure FDA0003637924340000017
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user A, α 1 (n) is the reflection coefficient of the first unit at the nth time, where α 1 (n)= 1,
Figure FDA0003637924340000018
represents the channel at the nth time between the base station and the first unit of the new reconfigurable smart surface, x p (n) represents the pilot signal sent by the base station at the nth time, and w A (n) represents the nth user A additive white Gaussian noise at a time; 由于α1(n)＝1，且接收端已知xp(n)，可以得到基站与用户A之间经过新型可重构智能表面反射的复合信道为：Since α 1 (n)=1, and x p (n) is known at the receiving end, the composite channel between the base station and user A that is reflected by the new reconfigurable smart surface can be obtained as:
Figure FDA0003637924340000019
Figure FDA0003637924340000019
 其中，
Figure FDA00036379243400000110
表示基站与用户A之间经过新型可重构智能表面反射的复合信道；in,
Figure FDA00036379243400000110
Represents the composite channel reflected by the new reconfigurable smart surface between the base station and user A; 所述步骤2中，经过新型可重构智能表面第1个单元的透射，用户B在第n个时刻接收到的离散基带等效信号
Figure FDA00036379243400000111
为：In the step 2, through the transmission of the first unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B at the nth time
Figure FDA00036379243400000111
for:
Figure FDA00036379243400000112
Figure FDA00036379243400000112
 其中，
Figure FDA00036379243400000113
表示新型可重构智能表面第1个单元与用户B之间第n个时刻的信道，β1(n)为第1个单元在第n个时刻的透射系数，此处β1(n)＝1，wB(n)表示用户B第n个时刻的加性白高斯噪声；in,
Figure FDA00036379243400000113
represents the channel at the nth time between the first unit of the new reconfigurable smart surface and user B, β 1 (n) is the transmission coefficient of the first unit at the nth time, where β 1 (n)= 1, w B (n) represents the additive white Gaussian noise of user B at the nth moment; 由于β1(n)＝1，且接收端已知xp(n)，可以得到基站与用户B之间经过新型可重构智能表面透射的复合信道为：Since β 1 (n)=1, and x p (n) is known at the receiving end, the composite channel transmitted by the new reconfigurable smart surface between the base station and user B can be obtained as:
Figure FDA00036379243400000114
Figure FDA00036379243400000114
 其中，
Figure FDA00036379243400000115
表示基站与用户B之间经过新型可重构智能表面透射的复合信道；in,
Figure FDA00036379243400000115
represents the composite channel transmitted between the base station and user B through the new reconfigurable smart surface; 所述步骤2中，将新型可重构智能表面的反射和透射系数分别设置为1，在第n时刻，基站控制新型可重构智能表面打开第1个单元，并关闭其它单元，可以得到用户A接收到经过新型可重构智能表面第1个单元反射回来的离散基带等效信号
Figure FDA0003637924340000021
为：In the step 2, the reflection and transmission coefficients of the new reconfigurable smart surface are set to 1 respectively. At the nth time, the base station controls the new reconfigurable smart surface to turn on the first unit and turn off other units. A receives the discrete baseband equivalent signal reflected by the first unit of the new reconfigurable smart surface
Figure FDA0003637924340000021
for:
Figure FDA0003637924340000022
Figure FDA0003637924340000022
 在接收端进行信道估计，并在所得结果中减去
Figure FDA0003637924340000023
即可得到基站与用户A之间经过新型可重构智能表面反射的复合信道；Channel estimation is performed at the receiver and subtracted from the result
Figure FDA0003637924340000023
The composite channel reflected by the new reconfigurable smart surface between the base station and user A can be obtained; 所述步骤2中，在第n+1时刻，基站控制新型可重构智能表面打开第2个单元，并关闭其它单元，此时用户A接收到经过新型可重构智能表面第2个单元反射回来的离散基带等效信号
Figure FDA0003637924340000024
为：In the step 2, at the n+1th time, the base station controls the new reconfigurable smart surface to turn on the second unit and turn off other units. At this time, user A receives the reflection from the second unit of the new reconfigurable smart surface. The discrete baseband equivalent signal that comes back
Figure FDA0003637924340000024
for:
Figure FDA0003637924340000025
Figure FDA0003637924340000025
 其中，
Figure FDA0003637924340000026
表示新型可重构智能表面第2个单元与用户A之间的信道，α2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且α2(n+1)＝1，
Figure FDA0003637924340000027
表示基站与新型可重构智能表面第2个单元之间第n+1个时刻的信道，xp(n+1)表示基站在第n+1个时刻发送的导频信号，wA(n+1)表示用户A第n+1个时刻的加性白高斯噪声；in,
Figure FDA0003637924340000026
represents the channel between the second unit of the new reconfigurable smart surface and user A, α 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and α 2 (n+1)=1,
Figure FDA0003637924340000027
represents the channel at the n+1th time between the base station and the second unit of the new reconfigurable smart surface, x p (n+1) represents the pilot signal sent by the base station at the n+1th time, w A (n +1) represents the additive white Gaussian noise at the n+1th moment of user A; 所述步骤2中，由于α2(n+1)＝1，且接收端已知xp(n)，可得到基站与用户A之间经过新型可重构智能表面反射的复合信道
Figure FDA0003637924340000028
为：In the step 2, since α 2 (n+1)=1, and the receiving end knows x p (n), the composite channel between the base station and the user A that is reflected by the new reconfigurable smart surface can be obtained.
Figure FDA0003637924340000028
for:
Figure FDA0003637924340000029
Figure FDA0003637924340000029
 所述步骤2中，经过新型可重构智能表面第2个单元的透射，用户B接收到的离散基带等效信号
Figure FDA00036379243400000210
为：In the step 2, through the transmission of the second unit of the new reconfigurable smart surface, the discrete baseband equivalent signal received by user B
Figure FDA00036379243400000210
for:
Figure FDA00036379243400000211
Figure FDA00036379243400000211
 其中，
Figure FDA00036379243400000212
表示新型可重构智能表面第2个单元与用户B之间的信道，β2(n+1)为新型可重构智能表面的第2个单元在第n+1个时刻的反射系数，且β2(n+1)＝1，wB(n+1)表示用户B第n+1个时刻的加性白高斯噪声；in,
Figure FDA00036379243400000212
represents the channel between the second unit of the new reconfigurable smart surface and user B, β 2 (n+1) is the reflection coefficient of the second unit of the new reconfigurable smart surface at the n+1th time, and β 2 (n+1)=1, w B (n+1) represents the additive white Gaussian noise of user B at the n+1th moment; 所述步骤2中，由于β2(n+1)＝1，且接收端已知xp(n)，可得到基站与用户B之间经过新型可重构智能表面透射的复合信道
Figure FDA00036379243400000213
为：In the step 2, since β 2 (n+1)=1, and x p (n) is known at the receiving end, the composite channel transmitted between the base station and user B through the new reconfigurable smart surface can be obtained.
Figure FDA00036379243400000213
for:
Figure FDA00036379243400000214
Figure FDA00036379243400000214
 步骤3，基站依次比较信道
Figure FDA0003637924340000031
和
Figure FDA0003637924340000032
的模的大小，筛选出
Figure FDA0003637924340000033
的单元序号，并将其对应单元存储为集合S；Step 3, the base station compares the channels in turn
Figure FDA0003637924340000031
and
Figure FDA0003637924340000032
the size of the modulo, filter out
Figure FDA0003637924340000033
the unit serial number of , and store its corresponding unit as a set S; 步骤4，基站将集合S以外的单元关闭，并将集合S中单元的反射和透射系数分别设置为
Figure FDA0003637924340000034
和
Figure FDA0003637924340000035
Step 4, the base station turns off the units other than the set S, and sets the reflection and transmission coefficients of the units in the set S to be
Figure FDA0003637924340000034
and
Figure FDA0003637924340000035
 步骤5，用户A和用户B分别发送信号
Figure FDA0003637924340000036
和
Figure FDA0003637924340000037
至基站；Step 5: User A and User B send signals respectively
Figure FDA0003637924340000036
and
Figure FDA0003637924340000037
to the base station; 步骤6，基站将xB(n)作为噪声，解调xA(n)得到用户A接收信号
Figure FDA0003637924340000038
Step 6, the base station uses x B (n) as noise, and demodulates x A (n) to obtain the received signal of user A
Figure FDA0003637924340000038
 步骤7，基站抵消xA(n)的干扰后，解调xB(n)得到用户B的接收信号
Figure FDA0003637924340000039
Step 7, after the base station cancels the interference of x A (n), demodulates x B (n) to obtain the received signal of user B
Figure FDA0003637924340000039
 2.如权利要求1所述的基于新型可重构智能表面的非正交多址接入方法，其特征在于：所述步骤6还包括，假设用户与基站之间的直接信道被阻挡，基站在第n个时刻接收到的离散基带等效信号rBS(n)为：2. The non-orthogonal multiple access method based on the novel reconfigurable smart surface according to claim 1, wherein the step 6 further comprises, assuming that the direct channel between the user and the base station is blocked, the base station The discrete baseband equivalent signal r BS (n) received at the nth time is:
Figure FDA00036379243400000310
Figure FDA00036379243400000310
 进一步的，由于用户A的信道条件较好，基站会先将用户B的信号xB(n)作为噪声，解调用户A的信号xA(n)，得到解调后的用户A接收信号
Figure FDA00036379243400000311
Further, since the channel condition of user A is better, the base station will first use the signal x B (n) of user B as noise, demodulate the signal x A (n) of user A, and obtain the demodulated signal received by user A.
Figure FDA00036379243400000311
Figure FDA00036379243400000312
Figure FDA00036379243400000312
 3.如权利要求2所述的基于新型可重构智能表面的非正交多址接入方法，其特征在于：所述步骤7还包括，基于SIC技术，基站先抵消用户A产生的干扰后，再解调用户B的数据，即：3. The non-orthogonal multiple access method based on the novel reconfigurable smart surface as claimed in claim 2, wherein the step 7 further comprises, based on the SIC technology, after the base station first cancels the interference generated by the user A , and then demodulate the data of user B, namely:
Figure FDA00036379243400000313
Figure FDA00036379243400000313
 其中，yB(n)表示抵消干扰后的用户B的接收信号，
Figure FDA00036379243400000314
表示
Figure FDA00036379243400000315
经过硬判或软判后重新生成的符号，最终得到用户B的接收信号
Figure FDA00036379243400000316
为：where y B (n) represents the received signal of user B after interference cancellation,
Figure FDA00036379243400000314
express
Figure FDA00036379243400000315
After hard judgment or soft judgment, the regenerated symbol finally obtains the received signal of user B
Figure FDA00036379243400000316
for:
Figure FDA00036379243400000317
Figure FDA00036379243400000317
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* Cited by examiner, † Cited by third party
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EP4461001A1 (en) * 2022-01-07 2024-11-13 Qualcomm Incorporated Usage of a reconfigurable intelligent surface in wireless communications
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110225538A (en) * 2019-06-21 2019-09-10 电子科技大学 The non-orthogonal multiple access communications design method of reflecting surface auxiliary
CN110234160A (en) * 2019-06-10 2019-09-13 东南大学 A kind of downlink transmission method suitable for non-orthogonal multiple access system
CN112153653A (en) * 2020-09-23 2020-12-29 南京邮电大学 Reconfigurable intelligent surface-assisted NOMA downlink low-power-consumption transmission method
CN113271597A (en) * 2021-04-15 2021-08-17 广东工业大学 Safety communication optimization method for reconfigurable intelligent surface assisted non-orthogonal multiple access

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102639615B1 (en) * 2017-02-07 2024-02-22 삼성전자주식회사 Apparatus and method for supporting multiple access in wireless communication system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110234160A (en) * 2019-06-10 2019-09-13 东南大学 A kind of downlink transmission method suitable for non-orthogonal multiple access system
CN110225538A (en) * 2019-06-21 2019-09-10 电子科技大学 The non-orthogonal multiple access communications design method of reflecting surface auxiliary
CN112153653A (en) * 2020-09-23 2020-12-29 南京邮电大学 Reconfigurable intelligent surface-assisted NOMA downlink low-power-consumption transmission method
CN113271597A (en) * 2021-04-15 2021-08-17 广东工业大学 Safety communication optimization method for reconfigurable intelligent surface assisted non-orthogonal multiple access

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
A Simple Design of IRS-NOMA Transmission;Zhiguo Ding 等;《IEEE Communications Letters》;20200217;第24卷(第5期);第1119-1123页 *
MIMO-NOMA Networks Relying on Reconfigurable Intelligent Surface: A Signal Cancellation-Based Design;Hou, TW 等;《IEEE Transactions on Communications》;20200820;第68卷(第11期);第6932-6944页 *
Non Orthogonal Multiple Access Using Reconfigurable Intelligent Surfaces;Alnwaimi, G 等;《WIRELESS PERSONAL COMMUNICATIONS》;20210701;第121卷(第3期);第1607-1625页 *
无线通信系统中的智能反射面研究综述;周游 等;《信息工程大学学报》;20210630;第22卷(第3期);第277-282页 *

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