| 摘要: |
| 针对星载船舶自动识别系统(AIS)无法避免的信号混叠问题，研究了AIS系统中应用最广泛的1比特差分和2比特差分解调，提出了一种1、2、3比特联合差分反馈的AIS信号非相干解调算法。该算法基于贝叶斯线性模型建立了最大似然估计的1、2、3比特联合差分解调结构，验证了在加性高斯信道中该算法比传统非相干解调算法有更好的抗信号混叠能力。仿真实验表明：该算法的解调误码率与1、2比特联合差分及2、3比特联合差分相比，当误码率（BER）等于10-2时，在加性高斯信道(AWGN)下具有1.5 dB的性能优势，同道干扰信道(CCI)下具有1～2 dB的性能优势。 |
| 关键词: 星载AIS 非相干解调 差分反馈 误码率分析 |
| DOI： |
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| 基金项目: |
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| An improved non-coherent demodulation algorithm for satellite-based AIS signals |
| CHENG Huan,WANG Xiao-hua,CAO Zhi-feng |
| () |
| Abstract: |
| A non-coherent algorithm based on combined 1, 2 and 3-bit differential detection with decision feedback is proposed in this paper to demodulate AIS (Automatic Identification System) signals, so as to enhance the abilities of the widely-used 1 and 2-bit differential detection ones in adaptation to co-channel interference(CCI). The algorithm is based on the Bayesian linear model, and establishes a maximum likelihood detection formulation. Theoretical analysis demonstrates the predominance of the proposed algorithm against the existing non-coherent counterparts in adaption to CCI. Simulation results then show that, when compared with the two algorithms developed via 1 and 2-bit joint differential detection and 2 and 3-bit joint differential detection with the bit error rate(BER) is set to 10-2, the proposed algorithm gains an improvement of 1.5 dB in signal-to-noise ratio (SNR) in the case of additive white Gaussian noise (AWGN), and an improvement of 1～2 dB in signal-to-interference ratio (SIR). |
| Key words: satellite-based AIS non-coherent demodulation differential detection with decision feedback bit error rate analysis |
《电讯技术》编辑部 