非理想水声信道下微弱信号分布式量化检测

Quantization-Based Distributed Detection Method for Weak Signals in Non-Ideal Acoustic Channels

分布式水声无线探测网是实现远程水下目标探测的有效途径,而其中的首要任务是进行水下分布式检测。针对水声传输传播时延大、可用带宽窄,无法实现水声阵列采集原始数据实时传输的限制,以及现有分布式量化检测方法在低信噪比下性能不佳的问题,提出了非理想信道下基于局部最大势检验的多比特量化检测方法。首先,结合水声信道衰落特性与编码信道传输差错特点,建立了非理想信道下水下无线传感网络弱信号检测模型,并将其转化为渐近单边假设检验问题;其次,推导了基于多比特量化的局部最大势检测方法,并对该方法的虚警概率和检测概率进行了理论分析;然后,构造了非理想信道下基于局部最大势检验的多比特量化阈值优化问题,分析了量化带来的检测性能损失;最后,通过仿真实验验证了所提方法及相关理论分析的有效性。

Distributed underwater wireless sensor network(UWSN)is a compelling approach for underwater target explora⁃tion,and its main objective is underwater distributed detection.Due to the limitations of large propagation delay and nar⁃row available bandwidth in underwater acoustic data transmission,which make it intractable to handle real-time transmis⁃sion of raw data collected by underwater acoustic array,and the poor performance of existing distributed quantization detec⁃tion methods under low signal-to-noise ratio,we propose a multi-bit quantization detection method based on locally most powerful test(LMPT)in non-ideal channel scenarios.Firstly,by combining the fading characteristics of underwater acoustic channel and the transmission error characteristics of coding channel,the UWSN weak signal detection model with non-ideal channels is conceived and further transformed into an asymptotic one-sided hypothesis test problem;Secondly,the locally most powerful detection method based on multi-bit quantization is derived,and its false alarm probability and detection probability are theoretically analyzed.Then,the problem of multi-bit quantization threshold optimization based on LMPT in non-ideal channels is proposed,and the detection performance loss introduced by quantization is investigated.Finally,the effectiveness of the proposed methods and related theoretical analysis is verified by the simulation results.