一种二用户协作HARQ通信方案

针对协作通信(cooperative communication)的重传问题,提出了在2个用户和基站之间的通信过程中,用户之间如何协作进行混合ARQ(hybrid ARQ)的方案. 通过分时发送机制,每个用户都保存对方上一次发送的数据,在收到基站的ACK/NACK后,根据基站的指示,从存储的上一次发送数据包中,寻找需要重传的数据包,并插入自己需要传送的新数据包,在下一个发送时隙中进行传输. 通过协作通信系统所实现的空间分集增益,提高了HARQ的性能. 比较2个用户分别独立与基站通信和相互协作与基站通信的HARQ方案,并通过理论分析和仿真,比较不同信噪比(SNR)下的吞吐量(throughput)和误包率(PER)以及平均时延,证实了本系统在可提高系统传输时延的前提下,具有更高的吞吐量和更低的PER.

A HARQ scheme based on two users' cooperation

This paper, aiming at retransmission problem in cooperative communication, proposes a new hybrid ARQ scheme when two users cooperatively communicate with the base station (BS). By sending packets in time-sharing slots, each user stores packets transmitted by its partner last time. After receiving ACK/NACK, each user searches for packets needed to be retransmitted according to indications of the BS. These packets mixed with newly generated ones are then forwarded in the next time slot. This scheme, utilizing space diversity gain introduced by the cooperative communication system, greatly improves the performance of hybrid ARQ. We compared our cooperative system with another system where each user communicates with the BS independently. Through comparisons of throughput, PER, and average delay varying with SNR, we proved that our system could achieve higher throughput and lower PER in the same channel state while increasing the average delay during theoretical analysis and simulation.