时频分布的BPSK瞬时带宽及编码识别

BPSK Instantaneous Bandwidth and Code Recognition Based on Time Frequency Distribution

针对二相编码信号存在180°相位跳变的现象,且传统定义的瞬时带宽不能反应二相编码信号的频域属性,将二相编码信号瞬时带宽定义为时频分布的二阶条件中心距,并推导出了瞬时带宽的表达式,得到了二相编码信号瞬时带宽在相位跳变点存在突变峰值,导致实际侦收时二相编码信号产生包络缺口现象。利用包络缺口,运用门限检测可以实现二相编码信号编码方式的识别,并且分析了信号相关参数变化对包络缺口深度的影响,仿真结果验证了理论分析的正确性。

Aimed at the problem that binary phase shift keying（BPSK）has 180°phase jump phenomenon,and the traditional definition of instantaneous bandwidth can＇t reflect the frequency properties of the BPSK.This paper defines the instantaneous bandwidth of BPSK as the second order central moments of time frequency distribution,derives the instantaneous bandwidth of the expression,and obtains the mutation peak value of the instantaneous bandwidth of the phase transition point to the actual interception BPSK generated envelope gap phenomenon.The paper utilizes the envelope gap for realizing the identification of coding mode of BPSK by using threshold detection,and analyzes the influence of the signal related parameters on the depth of envelope gap.The simulation results verify the correctness of the theoretical analysis.