卫星通信相位调制信号检测的仿真研究

Simulation Research on Phase Modulation Signal Detection in Satellite Communication

在卫星通信中,接收端要恢复发送端信息,必须对突发信号进行检测,检测到信号后再进行定时、载波参数估计,完成解调等操作。在实际工程应用中,噪声是不确定性因素,信号强度也存在差异,相关门限法采用固定的门限值,会影响漏检率和误检率,因此提出了一种基于独特码的相关归一化检测算法。上述算法首先对数据作差分相关计算来消除频偏的影响,然后与独特码作相关,在门限判决模块前进行归一化,减轻了噪声、信号强度不同情况下对信号检测的影响,降低了漏检率和误检率。仿真结果证实,该算法可以准确检测突发连续相位调制信号,并提高检测性能。

In the satellite communication, it is necessary to detect the burst signal for the receiver to restore the sender information. The timing, carrier parameter estimation, demodulation and other operations will be carried out after the signal is detected. In practical engineering application, using a fixed threshold in correlation threshold method will affect the rate of missed detection and false detection, because of the uncertainty of the noise and the differences of the signal intensity. Therefore, an algorithm of signal detection using normalized correlation based on unique codes is proposed in this paper. First, differential correlation calculation was used to eliminate the influence of frequency offset. Then, this result was used to do correlation calculation with the unique code and the normalization was processed before the threshold decision. This algorithm reduces the impacts of noises and signal intensity under different conditions on the signal detection, and lowers the rate of missed detection and false detection. The simulation results show that the algorithm can accurately detect the burst phase modulation signal and improve the detection performance.