自组织网络中前导信号设计及检测算法研究

初始化链路建立过程中前导信号的捕获和解调是自组织网络通信的关键.目前常规OFDM调制前导结构存在快速捕获与时频同步精度较难兼顾的问题,导致接收端定时同步误差较大,从而影响后续寻呼信息的解调性能.基于OFDM调制前导结构的性能分析,提出了异码级联和自循环级联两种前导信号设计和同步方案.仿真与分析表明,与已有方法相比,所提方案不仅能保证接收端较短的捕获时间和较高的频率同步准确性,同时也能显著提高定时估计性能.

The Study of Preamble design and Detection Algorithm in Ad Hoc Network

It is very important for the network communication in the Ad Hoc networks to capture and demodulate the preamble.However,the synchronization precision of the time is always not guaranteed when the common preamble structure is quick captured.Thus,the timing estimation of the receiver is not good enough to demodulate the signal.Based on the analysis of common preamble structure,two schemes,the concatenation of different codes and self-cycling are proposed,for synchronizing and designing the preamble structure.Consistent with the theoretical analysis,the simulation results indicate that the system is characterized by short detection time and reliable frequency offset estimation.What's more,the scheme offers the great improvement on the timing estimation.