| 摘要: |
| 针对低速π/4-DQPSK差分解调过程中因大频偏导致的性能恶化问题，提出了一种基于相关峰检测的频差估计算法。该算法利用已知发送的M序列对接收信号进行相关检测，根据频偏对同相（I）和正交（Q）两路相关峰值的不同影响进行频偏估计。给出了该算法的理论推导，并将其与传统的Kay估计、Fitz估计、L&R估计进行仿真对比。结果表明，该算法估计范围相当,为符号速率的一半；估计精度略差，信噪比大于0 dB时均方误差优于2×10-4，但显著降低了运算量与实现复杂度，具有很好的工程实用价值。 |
| 关键词: 跳频通信 π/4-DQPSK差分解调 频差估计 相关峰检测 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目(61301158) |
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| π/4DQPSK frequency offset estimation based on correlation peak detection |
| WEI Peng,LU Ruimin,XIE Shijun |
| () |
| Abstract: |
| A frequency offset estimation algorithm based on correlation peak detection is presented to solve the low symbol-rate π/4-DQPSK differential demodulation performance deterioration due to large frequency offset. This algorithm correlatively detects the received signal using known M sequence and the frequency offset is estimated based on the diffident effect on the correlation peak of inphase(I) channel and quadrature(Q) channel. Theoretical derivation of the algorithm is given and its capability is simulated and compared with Kay estimation,Fitz estimation and L&R estimation. Results show that this algorithm has similar estimation range which is half of symbol rate,slightly poorer estimation precision whose mean-square error(MSE) is superior than 2×10-4 with signal-to-noise ratio(SNR) greater than 0 dB ,but much less calculating amount and implementation complexity.It is more valuable in practical engineering. |
| Key words: frequency hopping communication π/4-DQPSK differential demodulation frequency offset estimation correlation peak detection |
《电讯技术》编辑部 