摘要全双工MIMO中继协作通信系统同传统的半双工中继系统相比，可以成倍增加源和目标节点信息交换速率，因此成为未来无线通信的最具潜力的关键技术之一。但是，在全双工模式下，中继收发端之间存在严重的自干扰，如果不抑制此干扰，系统性能会显著恶化。本文主要调研了中继站抑制全双工干扰的波束成形算法。主要研究工作如下：79784

(1)。 针对译码转发模式，研究中继站三种代表性的波束成形技术：零空间投影、最小均方误差算法、与最大化信干噪比联合最大化信泄噪比的中继端迭代波束成形算法。仿真结果表明：零空间投影复杂度最低，迭代算法误码率性能最优。

(2)。 针对放大转发协议，设计了基于最大化速率的中继波束成形方案，通过交替迭代梯度下降法求解逼近最优波束成形矩阵。仿真表明：同现有迫零与最小均方误差等算法相比，所提方案速率性能有一定提高。

毕业论文关键词：  全双工中继，译码转发，放大转发，波束成形，最小均方误差，梯度下降

毕业设计说明书外文摘要

Title      Full-duplex Beamforming Algorithm for MIMO relaying Cooperative communication systems             

Abstract Compared to traditional half-duplex relaying systems, full-duplex MIMO relaying cooperative communication systems can double the data exchange rate between source and destination nodes, and become one critical technology for the future wireless communication。 However, in full-duplex systems, there exists full-duplex self-interference at the relay station, due to the signal leakage from its transmitter to receiver, and this interference will seriously degrade the system performance。 This paper mainly investigates several beamforming schemes for self-interference suppression at relay station。 The main research content is as follows:

(1)。 In decoding-and-forwarding mode, three representative beamforming methods are investigated: null space projection (NSP), minimum mean square error (MMSE) and iterative beamforming structure (IBS) between maximizing signal-to-interference-and-noise ratio and maximizing signal-to-leakage-and-noise ratio。 Simulation results show that the NSP has the lowest complexity among them while the IBS algorithm is the best one among the three methods in the sense of bit error rate。

(2) In amplify-and-forward mode, the maximizing-rate bemaforming scheme at relay station is designed by using an alternating iterative algorithm and gradient descent method。 This scheme approaches the optimal solution。 Simulation results show that the rate-performance of the proposed method is better than those of zero-forcing and minimum mean square error algorithms。

Keywords  Full duplex, relay station, decode-and-forward, amplify-and-forward, beamforming, maximizing rate,  gradient descent

目   次

1  绪论 1

1。1  研究背景 1

1。2  全双工MIMO技术的发展与现状 2

1。3  论文结构 3

2  全双工MIMO中继协作通信系统基本原理 5

2。1  系统模型 5

2。2  波束成形算法 6

2。2。1 NSP算法 6

2。2。2 Max-SIR算法 7

2。3  检测算法 8

2。3。1 迫零检测 8

2。3。2 最小均方误差检测