摘要
在高速卫星通信系统中,随着信息传输速度的提高,码间串扰问题日益突出。为有效解决该问题,本文提出了一种先定时同步再双模式切换盲均衡算法。该算法通过定时同步对信号进行重采样,随后采用双模式切换机制:首先使用修正恒模算法进行初步均衡,以加快收敛速度并确保收敛方向正确;其次切换至改进判决引导算法,以获得更优的稳态性能。这种先对信号进行位定时以准确对齐信号的符号边界,再用双模式切换机制结合了修正恒模算法的快速收敛特性和判决引导算法的高精度均衡能力,特别适用于卫星通信中复杂多变的信道环境。通过与不同调制方式和信道的星座图、均方误差及码间串扰的对比分析,仿真结果表明,所提算法显著提升了星座图的清晰度和紧凑性,均方误差最大可降低18.77 dB,同时有效抑制码间串扰,最多降低14.32 dB,从而显著提高了通信系统的性能。
In high-speed satellite communication systems,the problem of inter-symbol interference(ISI)becomes increasingly prominent as the data transmission rate increases.To effectively mitigate this issue,this paper proposes a blind equalization algorithm that first performs timing synchronization followed by a dual-mode switching mechanism.The proposed algorithm initially employs timing synchronization to resample the received signal,ensuring accurate symbol boundary alignment.Subsequently,a dual-mode switching strategy is implemented:first,the Modified Constant Modulus Algorithm(MCMA)is applied for preliminary equalization,accelerating convergence and ensuring the correct convergence direction;then,the algorithm switches to an improved Decision-Directed(DD)equalization scheme to achieve superior steady-state performance.By integrating timing synchronization with the dual-mode switching mechanism,this approach leverages the rapid convergence property of MCMA and the high-precision equalization capability of the DD algorithm,making it particularly suitable for the complex and dynamic channel conditions encountered in satellite communications.Through comparative analyses of constellation diagrams,mean squared error(MSE),and ISI across different modulation schemes and channel conditions,simulation results demonstrate that the proposed algorithm significantly enhances constellation clarity and compactness.The MSE is reduced by up to 18.77 dB,while ISI suppression reaches a maximum improvement of 14.32 dB,thereby significantly improving the overall performance of the communication system.
作者
凌雨欣
张天骐
孙浩源
邹涵
Ling Yuxin;Zhang Tianqi;Sun Haoyuan;Zou Han(School of Communications and Information Engineering,Chongqing University of Posts and Telecommunications,Chongqing 400065,China)
出处
《电子测量技术》
北大核心
2025年第19期86-94,共9页
Electronic Measurement Technology
基金
国家自然科学基金(61671095,61371164,61071196)
重庆市自然基金(cstc2021jcyj-msxmX0836)项目资助。
关键词
卫星通信
盲均衡
定时同步
双模式算法
码间串扰
星座图
均方误差
satellite communication
blind equalization
timing synchronization
dual-mode algorithm
inter-symbol interference(ISI)
constellation diagram
mean squared error(MSE)
