中文说明：协作通信思想通过用户间彼此共享天线，互为通信中继，实现虚拟发射分集，从而为MIMO的实用提供了一个可行的思路。协作通信的核心问题是中继节点的协作协议。有两种最基本的中继协作方式放大转发（AF）与解码重传（DF），其它各种协作协议的研究，几乎均是建立在这两个固定中继协议之上。本文通过MATLAB仿真，来验证协作对通信的改善，并分析不同信道情况下的AF与DF表现，研究二者的实际性能与所面临的主要问题。
English Description：
The idea of cooperative communication realizes virtual transmit diversity by sharing antennas and relay between users, which provides a feasible idea for the practical application of MIMO. The core problem of cooperative communication is the cooperative protocol of relay node. There are two basic relay cooperation modes: amplify and forward (AF) and decode and retransmit (DF). Almost all other cooperation protocols are based on these two fixed relay protocols. In this paper, through MATLAB simulation, to verify the improvement of cooperation on communication, and analyze the performance of AF and DF under different channel conditions, and study the actual performance and main problems of both.