采用FSK调制的直接序列扩频水声通信技术  

A Simple,Reliable and Robust Direct-Sequence Spread-Spectrum (DSSS) Underwater Acoustic Communication Receiver Based on FSK Modulation

作　　者：张歆[1] 彭纪肖[1] 李国梁[1] 

机构地区：[1]西北工业大学航海学院,陕西西安710072

出　　处：《西北工业大学学报》2007年第2期177-180,共4页Journal of Northwestern Polytechnical University

摘　　要：水声信道的时变相位起伏使得实现可靠的相位跟踪比较困难,从而造成基于相位检测的水声通信接收机结构复杂。提出基于FSK调制的直接序列扩频(DSSS-FSK)水声通信系统。它采用FSK调制和非相干检测,对DSSS-FSK信号的相关解扩和RAKE解调方法进行了研究。数值仿真和湖试数据处理表明,DSSS-FSK信号兼有扩频信号抗多径、低截获概率和非相干检测简单可靠两方面的优点,特别适用于低信噪比、强多径的水声信道中。Aim. Existing DSSS receivers based on phase detection are generally complex because of timevariant phase fluctuation of underwater acoustic channel. In many underwater communication applications, the capability of a complex receiver is really more then enough but its robustness is deficient; so less complex but more robust receivers are needed. We now present the design of a simple, reliable and robust DSSS receiver based on frequency shift keying （FSK） modulation. In the full paper, we explain our design in detail; in this abstract, we just add some pertinent remarks to listing the one topic of explanation： （1） the model of DSSS-FSK receiver; Figs. 1 and 2 in the full paper give respectively the schematic of the DSSS-FSK receiver and that of its RAKE demodulator; in connection with Fig. 1, in order to simplify the processing of the receiver＇s signals, we adopt the procedure of demodulating first and then de-spectrumspreading; eqs. （1） through （6） in the full paper are all taken from the open literature but some of them have been modified for our design. We give the results of both laboratory numerical simulations and lake tests of the DSSS-FSK receiver built according to our design. Fig. 3 in the full paper shows the curves of BER （bit error rate） versus SNR （signal-to-noise ratio） under various conditions. Table 2 in the full paper shows data processing results of lake tests. The above-mentioned results show preliminarily that： （1） our DSSS-FSK receiver retains the advantage of multipath suppression and low probability of interception of DSSS signals and （2） its FSK modulation ensures simple and robust non-coherent detection. Therefore our design of a simple, reliable and robust DSSS-FSK underwater communication receiver is indeed satisfactory.

关 键 词：直接序列扩频 FSK调制 RAKE解调器 水声通信 

分 类 号：TN929.3[电子电信—通信与信息系统]