无线通信中联合信道估计和极化码译码研究

Joint Channel Estimation and Decoding of Polar Codes in Wireless Communications

针对无线通信传统接收机的信道估计和译码分开处理是次优的问题,文章提出了一种联合信道估计和极化码译码的接收机模型。根据极化码译码器级联的循环冗余校验码的校验信息,接收机将译码器中部分硬判决信息再编码,然后将得到的码字反馈到信道估计器中,此时相当于接收机挑选了部分码字比特作为导频,信道估计器根据新的导频重新进行信道估计。文章提出的接收机模型及算法不仅减少了信道估计中导频的开销,还使得信道估计和译码两个过程相互促进,从而改善了极化码的误帧率。仿真结果表明,当归一化多普勒等于0.02时,文章提出的基于硬判决反馈的接收机相比于传统的接收机有2 dB的性能增益。

In wireless communication,this separation of channel estimation and decoding is known to be sub-optimal in traditional receivers,so we propose a receiver model for joint channel estimation and polar code decoding.According to the result of the Cyclic Redundancy Check(CRC)code in decoders,the receiver will select some hard decision information to re-encode,and feedback the codeword to the channel estimator.At this time,it means that the receiver will select some codeword bits as the pilots,and the channel estimator will estimate the channel state information based on the new pilots again.The proposed receiver model and corresponding algorithm in this paper not only reduce the resources occupied by the pilots,but also boost the estimation and decoding,which can improve the performance of frame error rate.For fast fading channel with the normalized Doppler spread of 0.02,2 dB performance improvement will be achieved when comparing with the traditional receiver.