云接入网中无速率编码上行传输方案  

Uplink Transmission Scheme based on Rateless Coding in C-RAN

作　　者：张昱 谢灵杰 张业帆 华惊宇[1] 孟利民[1] ZHANG Yu;XIE Ling-jie;ZHANG Ye-fan;HUA Jing-yu;MENG Li-min(College of Information Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310023,China)

机构地区：[1]浙江工业大学信息工程学院,浙江杭州310023

出　　处：《信号处理》2018年第10期1178-1187,共10页Journal of Signal Processing

基　　金：浙江省自然科学基金(LY17F010014)

摘　　要：本文考虑云接入网(C-RAN)中基于无速率编码(Rateless code)的单用户上行传输系统。系统是由单用户,多个射频拉远头(RRH)以及基带处理单元(BBU)池组成。用户将要发送的信息采用无速率码进行编码并经过调制后发送;覆盖该用户的各个RRH将收到的信号进行量化后通过高速链路传输给BBU池; BBU池将收到的量化信号利用置信传播(BP)算法进行联合解压缩以及译码。为了进一步提升系统性能,本文利用外信息传递(EXIT)分析对用户无速率码度数分布进行了优化。仿真结果表明,经过度数分布优化的无速率码相较于删除信道最优度数分布在误码率(BER)和吞吐量上均有所提升,且接近理论上限。This paper considers single user uplink transmission based on rateless coding in Cloud Radio Access Network(C-RAN).The system consists of one user,multiple remote radio head(RRH)and a baseband unit(BBU)pool.The user encodes the messages with rateless code which are then modulated and sent.Each RRH which covers the user quantizes the received signals and transfers them to the BBU pool through the high rate link.The BBU pool applies belief propagation(BP)algorithm for joint decompression and decoding for the received quantized signals from all the RRHs.In order to further improve the system performance,this paper resort to the extrinsic mutual information transfer(EXIT)analysis to optimize the degree profile of the rateless code implemented by the user.The simulation results show that the rateless code with optimized degree profile achieves a lower bit error ratio(BER)as well as a higher throughput,compared with the optimal degree profile under the binary erasure channel(BEC).Moreover,the performance of the optimized profile approaches the theoretical limit of the system.

关 键 词：云接入网 无速率码 置信传播算法 外信息传递 

分 类 号：TN92[电子电信—通信与信息系统]