基于序列判决和相位排序的GLRT最优序列检测算法

Sequence decision and phase sorting based GLRT optimal sequence detection algorithm

为了实现平坦衰落信道中正交调制信号的最优非相干序列检测,提出了一种新的广义似然比检验的最优非相干序列检测算法,对于瑞利衰落信道,算法等价于最大似然非相干序列检测器。首先得到在第n个时隙的关于信息符号xn的判决,并根据判决在给定的相位区间内的改变形成一个判决序列;然后对判决序列发生改变处的相位进行排序,从而识别出对应区间上的目标序列;理论分析结果表明,提出的BFSK最优序列检测可应用于现代射频识别系统中采用FM0信号的最优非相干序列检测。仿真实验结果表明,提出的最优序列检测算法有与传统的ML相干序列检测算法相比拟的误码率/误符号率(BER/SER)性能,与传统的穷举搜索方法相比,大大降低了计算复杂度。

To implement the optimal noncoherent sequence detection of quadrature modulated signals in flat fading channels,a new algorithm that performs generalized-likelihood-ratio-test optimal incoherent sequence detection is proposed in this paper.Moreover,for Rayleigh fading channels,the proposed algorithm is equivalent to the maximum-likelihood noncoherent sequence detector.Firstly,the decision on the information symbol xn at the nth time slot is obtained by the algorithm,and a decision sequence is formed according to the change of the decision in a given phase interval.And then the phases where the decision sequence changes are sorted in order to identify the target sequences on the corresponding intervals.The theoretical analysis results show that the proposed BFSK optimal sequence detection can be applied to the detection of the optimal incoherent sequence of FM0 signals used in modern radio frequency identification systems.And the simulation results show that the proposed optimal sequence detection algorithm has nearly equal BER/SER performance to the traditional ML coherent sequence detection algorithm.Compared with the traditional exhaustive search algorithm,the proposed algorithm greatly reduces the computational complexity.