基于OFDM-IM的认知无线电协作中继性能分析

Performance Analysis of OFDM-IM-based Cooperative Relaying Protocol for Cognitive Radio Networks

该文针对协作认知无线电网络场景,提出一种基于索引调制正交频分复用(OFDM-IM)的新型协作中继设计方法。该方法将OFDM-IM技术应用于从用户发送端,将从用户的传输空间划分为信号空间和索引空间。从用户在其信号空间上转发主用户的信息,同时在索引空间传输从用户信息。通过这种方式,主、从用户之间不存在相互干扰。针对此模型,该文分析了主、从用户的误码率,理论推导了相关表达式,并讨论了从用户的位置对主、从用户性能的影响。仿真结果表明,该文所提设计方法能够同时提升主、从用户的误码率性能,且均优于传统的基于OFDM的协作中继方式。

A novel two time slots Orthogonal Frequency Division Multiplexing-Index Modulation （OFDM-IM）- aided cooperative relaying protocol is proposed for Cooperative Cognitive Radio Networks （CCRN）. In the proposed scheme, OFDM-IM technique is used at the Secondary User （SU） to split the transmission space into the signal constellation domain and the index domain. Specifically, the Secondary Transmitter （ST） of SU acts as a Decode-and-Forward （DF） relay to transmit the information of the Primary User （PU） in the signal constellation domain, while the information bits of SU are carried by the index domain. Through this design concept, the mutual interference between the PU and SU can be avoided. Upper bounds on the Bit Error Probabilities （BEPs） of the PU and SU are analytically derived. The influence of ST＇s location to the BER performance of PU and SU is also analysed. Several numerical results and discussions are provided to substantiate the theoretical analysis, and it is shown that the proposed protocol is a viable candidate for OFDM-based CR networks since it can enhance the BER performances of both PU and SU.