为解决双向中继信道中采用低密度奇偶校验码LDPC(low density parity check code)或Turbo码的网络编码系统信道编码编译码算法及设备的复杂度太高这一问题,提出一种联合Polar编码与网络编码的中继转发策略.该策略利用无线通信中信号的叠加特性和Polar编码、网络编码的线性性质直接估计网络编码的码字,使得中继节点进行Polar译码的复杂度和信源节点之间的信息交换时间都比直接网络编码系统减少了50%.同时,由于基于信道极化理论的Polar码具有在离散无记忆信道BDMC(binary discrete memoryless channel)上达到信道容量及编译码算法简单等优点,使得所提方案不仅保证了系统的可靠性,而且更容易实现.仿真结果验证了该方案的有效性.
In order to solve the problem of the high complexity of channel encoding/decoding algorithms and real equipment for the networking coding system with LDPC code or Turbo code in two way relay channel, a new combination scheme of Polar channel code and physical network coding is proposed. This scheme utilize the superposition of wireless signals and the linear property of Polar code and network coding to estimate the network codeword directly, thus reduce 50% the decoding complexity of relay node and 50% the information exchange time between source nodes than that of the direct network coding. Simultaneously, Polar code which based on the channel polarization can achieve channel capacity on BDMC with low complexity of encoding and decoding algorithms, so the proposed scheme can be applied easily with reliability, and the simulation results also verified the effectiveness of the scheme.