中频带宽对调频遥测非相干解调性能影响分析

Influence of Intermediate Frequency Bandwidth Setting on Non-coherent Demodulation Performance of FM Telemetry System

遥测地面站设备多采用非相干鉴频解调,设备接收机需要根据码速率来设置中频带宽,中频带宽设置不合理会导致遥测解调误码率增高。为在国军标规定的档数中选出不同码速率的相应最佳中频带宽,文中根据FM信号的解调原理,对非相干鉴频解调方式下,中频带宽对解调误码率性能的影响进行了仿真分析,依据仿真结果提出了最优误码性能下中频带宽参数的推荐值为1.7倍码速率,最后通过硬件实验对仿真分析结果进行了验证。

Non-coherent demodulation is often adopted in Telemetry station equipment, which requires the receiver to set the intermediate frequency （IF） bandwidth based on the code rate. Unreasonable IF bandwidth will lead to increased telemetry demodulation error rate. The military standard defines the choice of different number of stalls IF bandwidth. The influence of intermediate frequency bandwidth of BER performance is simulated and analyzed in order to select the appropriate optimal intermediate frequency bandwidth for different code rates according to the principle of FM signal demodulation for non coherent frequency discrimination demodulation method. The simulation results show that the optimal bit error rate （BER） performance is obtained with a recommended value of 1.7 times the code rate for the intermediate frequency bandwidth parameters. The simulation analysis results are verified by hardware experiments.