基于信道状态感知的多信道认知多址接入协议

摘要

针对多信道认知无线网络中预约信道与多个数据传输信道的状态不一致会降低认知多址协议性能的问题，提出了基于数据信道状态感知的多信道认知多址协议--CAM-MAC协议。该协议在预约信道上优化握手机制来减少平均成功预约时长；而在Nakagami衰落数传信道上采用跨层方法设计了基于瞬时SNR的自适应传输机制来提高数据传输速率。通过上述机制，CAM-MAC协议可以有效提升系统性能。分析与仿真均表明：该协议在饱和吞吐量上有较大提升，在特定场景下可提高约50%。%For multi-channel cognitive radio network (CRN), the inconsistent transmission conditions of common control channel (CCC) and data channels deteriorate the performance of cognitive MAC protocols. Focusing on this problem, a novel channel aware multi-channel cognitive MAC protocol (CAM-MAC) was proposed, which consists of two-level four-way handshaking mechanism. The first level two-way handshaking was optimized to reduce the mean successful reservation time on CCC. The other level two-way handshaking was implemented by a cross-layer approach to adopt the adaptive transmission based on instantaneous SNR on each Nakagami fading data channel to improve the data rate. These mechanisms improve the performance of CAM-MAC. Simulation results validate the throughput of CAM-MAC outper-forms that of the existing one, about 50%improvement in the throughput under certain conditions.