基于协作中继的多点广播码分多址信息系统设计

Design of Multicast Code Division Multiple Access Information System Based on Cooperative Relay

为了提高多群多点广播中继网络系统的性能,提出一种改进的协作中继多点广播码分多址(CDMA)系统设计。该方案利用协作中继辅助的分布式波束形成实现单天线基站多播,获得了较好的空间分集增益。在该系统中,多个基站利用多个中继节点向多个目的地的各个小组传播消息;利用CDMA技术来减少中继节点以及目的地节点的多址干扰(MAI)障碍,同时每个中继节点作为线性预编码波束合成器,可以在合适的代码空间重塑基站信号;对线性波束形成矩阵进行优化,使得中继节点的功率最小化,从而满足QoS在信号干扰噪声比方面的要求。系统性能仿真对比实验的结果表明,提出的改进方案明显优于传统的正交复用方案(FDMA/TDMA)。

In order to improve the performance of multigroup multicast relay network system,an improved cooperative relay multipoint broadcast code division multiple access（CDMA）system was proposed.In this scheme,the distributed beamforming based on cooperative relaying is used to realize the multicast of single antenna base station,and a better spatial diversity gain is obtained.In this system,aplurality of base stations use multiple relay nodes to multiple destinations in each group to spread the news.CDMA techniques are used to reduce the relay node and the multiple access interference（MAI）barrier of the destination node.Each relay node as a linear precoding beamformer can reshape the space base station signal in the appropriate code.The linear beamforming matrix is optimized to make the power relay nodes minimize,so as to meet the requirements of QoS in signal to interference noise ratio.Through the contrast experiment,the performance of the system simulation shows that the proposed scheme outperforms the conventional orthogonal multiplexing scheme（FDMA/TDMA）.