光通信研究Issue(3)：113-118,6.DOI:10.13756/j.gtxyj.2024.230023
基于低轨卫星PCMA信号的信道估计算法研究
Research on Channel Estimation Algorithm based on LEO Satellite PCMA Signal
摘要
Abstract
[Objective]With the development of the space-ground integrated information network,the Low Earth Orbit(LEO)satellite communication system is ushering in a development boom.The Paired Carrier Multiple Access(PCMA)technology is gradually developing to the low-orbit satellite communication due to its advantages of saving bandwidth resources.However,tra-ditional PCMA technology is mostly used in high-orbit satellites,and cannot adapt to the highly dynamic fading channel character-istics of low-orbit satellite channels,which greatly degrades the bit error performance of the PCMA receiver.The bottleneck lies in the channel estimation and equalization technologies for overlapping signals.[Methods]Aiming at the channel characteristics of LEO satellites,this paper proposes a channel estimation scheme that combines training sequence estimation and Autoregressive(AR)model prediction.Based on the idea of superimposed training sequence channel estimation,an iterative method suitable for PCMA mixed signal channel estimation is introduced to improve the accuracy of training sequence channel estimation through iter-ation.The AR model is used to predict the Channel State Information(CSI)of the data sequence in real time.The use of AR model can also reduce the frequency of channel estimation in training sequences,so as to adapt to the dynamics of LEO satellite channels.[Results]The simulation results show that the idea of superimposed training sequence channel estimation can be applied to the PCMA signals,and accurate channel estimation can be obtained after iterations.The method proposed in this paper can ef-fectively improve the accuracy of channel estimation.After signal separation and demodulation,the bit error rate can reach the or-der of 10-3 when the signal-to-noise ratio is greater than 9 dB.[Conclusion]A channel estimation method for PCMA signal is pro-posed in this paper.The simulation results show that the bit error rate loss is within an acceptable range,which can support the ap-plication of PCMA technology in low-orbit satellite communication.The proposed algorithm has the advantages of simple struc-ture,low complexity,and high practical value.关键词
低轨卫星/成对载波多址/信道估计/自回归模型Key words
LEO satellite/PCMA/channel estimation/AR model分类
信息技术与安全科学引用本文复制引用
王宇琦,江诗禹,刘子威,张更新..基于低轨卫星PCMA信号的信道估计算法研究[J].光通信研究,2024,(3):113-118,6.基金项目
国家自然科学基金资助项目(62171234,U21A20450,61971440) （62171234,U21A20450,61971440）
江苏省前沿引领技术基础研究专项资助项目(BK20192002) （BK20192002）
