基于网络编码的衰落信道频谱感知算法

针对传统认知无线电网络中频谱状态转换频繁和频谱检测时延长的问题，提出基于随机线性网络编码的累积和能量检测频谱感知算法。该算法在主用户信道中引入随机线性网络编码，利用网络编码对频谱的整形作用，使频谱状态转换稀疏，频谱结构更规律化，减小频谱检测时延，提高系统吞吐率。此外，针对传统累积和能量检测算法抗衰落性能差的问题，通过比较该算法在五种衰落信道下的检测时延和吞吐率，研究该算法的抗衰落性能。实验结果表明，在一定的虚警概率下，该算法有效降低了检测时延，提高了吞吐率及抗衰落能力，能够更好地适应复杂的衰落信道环境。

A spectrum sensing algorithm based on network coding over various fading channels

A cumulative summation(CUSUM) spectrum sensing algorithm based on random linear network coding(RLNC) is proposed to address the problem that spectrum states transfer frequently and the detection delay is large in the traditional cognitive radio(CR) network. In the proposed algorithm,RLNC is introduced to primary user(PU) subnetwork in the CR network and shapes traffic. Consequently,transitions between spectrum states are expected to be less frequent and the spectrum structure is of more regularity,which,in turn,results in great improvement in detection delay and throughput rate. In addition,since the anti-fading performance of the traditional CUSUM algorithm is poor,this paper investigates the anti-fading performance of the proposed algorithm by comparing the detection delay and throughput rate when the received signal experiences five kinds of fading channels. Simulation results show that the proposed algorithm provides great improvement in detection delay,throughput rate and anti-fading performance at a certain false alarm probability,and it can be better adapted to the complex fading channel environment.