| 摘要: |
| 为了解决正交时频空（Orthogonal Time Frequency Space，OTFS）系统中经典的消息传递（Message Passing，MP）检测算法存在的误差平台现象和收敛较慢的问题，提出了一种结合可变收敛阈值（Variable Convergence Threshold，VCT）和双概率限幅（Double Probability Clipping，DPC）的改进MP算法。VCT机制根据信道噪声方差动态调整收敛阈值，DPC机制先根据信道噪声方差动态选择限幅阈值对，再根据发送符号的最大概率动态选择限幅强度。仿真结果表明，与MP算法相比，所提算法在保持复杂度近似不变的情况下，有效降低了误比特率（Bit Error Rate，BER），在BER为10-5时获得大约5 dB的性能增益。 |
| 关键词: 正交时频空（OTFS） 信号检测 消息传递 可变收敛阈值 双概率限幅 |
| DOI：10.20079/j.issn.1001-893x.250320001 |
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| 基金项目:国家自然科学基金资助项目（62171235） |
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| An OTFS Message Passing Detection Algorithm with Variable Convergence Threshold and Double Probability Clipping |
| ZHANG Kehan,HE Xueyun |
| (School of Telecommunications and Information Engineering，Nanjing University of Posts and Telecommunications，Nanjing 210003，China) |
| Abstract: |
| The classical message passing(MP) detection algorithm suffers from the error floor phenomenon and slow convergence in the orthogonal time frequency space(OTFS) systems.To address the shortcomings，an improved MP algorithm combining variable convergence threshold(VCT) and double probability clipping(DPC) is proposed.The VCT mechanism dynamically adjusts the convergence threshold based on the channel noise variance，while the DPC mechanism first dynamically selects the clipping threshold pair based on the channel noise variance and then dynamically selects the clipping intensity based on the maximum probability of the transmitted symbols.Simulation results show that，compared with the MP algorithm，the proposed algorithm effectively reduces the bit error rate(BER) while maintaining a similar complexity，achieving approximately 5 dB performance gain at a BER of 10-5. |
| Key words: orthogonal time frequency space（OTFS） signal detection message passing variable convergence threshold double probability clipping |
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