| 摘要: |
| 针对大动态低码率PCM/FM遥测信号的可靠接收问题展开研究，给出了一种基于连续相位调制（CPM）信号原理的载波频偏矫正及差分序列检测的非相干接收方案。针对限幅鉴频、多符号检测及差分序列检测等3种非相干解调算法，介绍了各自应用于PCM/FM信号的算法原理，并比较了3种算法的解调性能及对大动态环境的适应能力。计算机仿真表明，在无残留频偏情况下，2符号相位差分序列检测性能最好；但在0.05倍码速率的残留频偏下，1符号相位差分序列检测的性能更好，优于2符号相位差分序列检测、限幅鉴频检测和多符号非相干检测。对PCM/FM信号的讨论包含了几种典型的非相干解调，对大动态环境下的PCM/FM接收有重要的参考价值。 |
| 关键词: PCM/FM 大动态 非相干解调 差分解调 |
| DOI： |
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| 基金项目:国家自然科学基金-中物院NASF联合基金项目（10876103） |
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| Non-coherent demodulations for large dynamic PCM/FM telemetry signal |
| XIE Shun-qin,WANG Shi-lian,YANG Chun |
| () |
| Abstract: |
| Reliable receptions for pulse-code modulation/frequency modulation (PCM/FM) telemetry signal with low-bit-rate in large dynamic conditions are studied. A non-coherent scheme based on continuous phase modulation (CPM) principles is proposed, which includes the correction of carrier frequency offset and differential phase sequence detection by Viterbi algorithm. Principles of three types of non-coherent demodulations for PCM/FM, i.e. limited-discriminator detection, multiple-symbol detection and differential phase sequence detection, are discussed. Their detection performances and adaptabilities to large dynamic conditions are compared as well. Computer simulations show that the sequence detection for 2-symbol phase difference performs the best when without residual Doppler frequency offset. While with a frequency offset of 0.05 times of symbol rate, the sequence detection for 1-symbol phase difference is better than that for the 2-symbol phase difference, and also better than the other two methods. The discussions about PCM/FM signal include three typical non-coherent demodulations, which are important references to the receptions of PCM/FM signal in large dynamic conditions. |
| Key words: PCM/FM large dynamic non-coherent demodulation differential detection |
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