基于迫零中继和广义差分调制的双向TDBC中继网络

摘要

在时分广播网络(TDBC)中采用迫零中继方案,显著降低了接收端的中断概率,但迫零中继方案能否降低误码率仍需要探讨,于是提出基于迫零中继和广义差分调制的双向TDBC协议的网络.在信源端,先对信源发送信号作广义差分编码处理,然后在中继处迫零并相乘转发,在信源端将接收来自另一信源和中继的信号进行合并,用差分检测方式检测误码率.仿真结果表明,在较高的信噪比情况下,相比传统不引入迫零中继的方案,该方法有较低的误比特率(BER)性能.同时,仿真分析块内参考符号和一般符号的功率分配对系统误比特率的影响,给出了最小化误比特率时的功率分配因子.%Differential transmission is applied to a two-way relay network (TWRN), so that the receiver does not need channel state information (CSI). However, the performance of the system could be further improved. In this paper, a generalized differential modulation (GDM) scheme for Zero-force relay power allocation and multiply-and-forward (MF) relaying is proposed. In the proposed scheme, each frame transmitted by the source is divided into several blocks, and each block consists of one reference symbol and several normal symbols. The reference symbol in each block is differentially encoded based on the previous reference symbol, whereas the normal symbols are differentially encoded based on the reference symbol in the same block. At the same time, to deal with the noise enhancement problem and improve the system performance, this paper proposes a zero-forcing based relay power allocation (ZF-RPA) scheme. The bit-error-rate (BER) performance of the proposed scheme is analyzed, and the power allocation among the RS and the NSs in each block also disscussed, thus to minimize the lower bound of BER. Simulation results indicate that the ZF-RPA scheme is fairly improved as compared with the traditional scheme.