针对线性调频信号同步相关的旁瓣、m序列扩频同步的序列自噪声和二进制相移键控调制信号在主瓣周围一个码片范围内存在较强烈的旁瓣三个问题,提出了一种基于二进制偏移载波(BOC)调制信号的无干扰窗水声同步方式.利用互补序列的非周期自相关函数之和为零的特殊性质,实现了在主瓣周围一个码片范围外,零相关窗范围内的无干扰窗.使用BOC(1,1)方式对信号进行亚载波调制,以减少主瓣周围一个码片范围内的旁瓣.对单通道信号和双通道信号的零相关窗形式都进行了设计,通过仿真和实验验证了BOC零相关窗方法在水声系统的同步、信道测量和估计中的有效性.
Aiming at the problem that synchronized correlation of linear frequency synchronization of m sequence possesses self noise and there are strong side lobes in a code range besides main lobe, in this paper we propose a new underwater acoustic synchronization scheme based on binary offset carrier (BOC) modulated signal with no interference windows which employs the property that the sum of aperiodic auto correlation function is 0 to realize no interference window between the range of one code and zero inference window and utilizes BOC (1, 1) to modulate signal with sub-carrier to mitigate side lobes in one code range besides main lobe. The schemes are designed for both single and couple channel signal, and the validity of underwater acoustic synchronization, channel measurement and estimation are testified through simulation and experiments.