PLNC-OFDM双向多中继系统中的联合子载波抑制与中继选择

Joint Subcarrier Suppression and Relay Selection for Two-Way OFDM Relaying System with PLNC

研究在多径瑞利衰落信道下采用译码转发的PLNC-OFDM双向多中继系统中联合子载波抑制与中继选择(JSSRS)问题,并提出两种JSSRS方法:固定抑制门限的JSSRS(FTJ)和固定子载波数目的 JSSRS(FNS-J).FT-J在一次双向信息交换过程中采用固定的抑制门限进行子载波抑制,FNS-J在一次双向信息交换过程中保持抑制的子载波数目恒定不变,即活跃子载波数目恒定不变而抑制门限动态变化.仿真结果表明,与传统的子载波抑制相比,所提出的FT-J和FNS-J不仅增强了系统可靠性,而且提高了系统有效性.

This paper deals with the joint subcarrier suppression and relay selection （JSSRS） problem in two-way orthogonal frequency division multiplexing （OFDM） relaying system based on physical layer network coding （PLNC） with the decode-and-forward pro- tocol over a multipath Rayleigh fading channel. Two JSSRS schemes are proposed： JSSRS with a fixed threshold （FT-J） and JSSRS with a fixed number of subcarriers （FNS-J）. In a two-way information exchange process, FT-J suppresses subcarriers by keeping the sup- pression threshold invariant, and FNS-J suppresses subcarriers by keeping the number of suppressed subcarriers invariant. In other words, FNS-J keeps the number of active sub- carriers constant and the suppression threshold value varying. Simulation results show that FT-J and FNS-J can improve efficiency and enhance reliability of a two-way OFDM relay- ing system based on PLNC as compared with traditional subcarrier suppression schemes.