【作者】 顾娜； 匡麟玲； 陆建华；

【Author】 Gu Na;Kuang Linling;Lu Jianhua;Electronic Engineering Department of Tsinghua University;Tsinghua Space Center;

【机构】 清华大学电子工程系； 清华大学宇航中心；

【摘要】 卫星动中通是当前卫星通信领域需求旺盛、发展迅速的一个重要应用领域,在军用和民用两个领域都有极为广阔的发展前景。甚小口径天线终端(VSAT)在卫星动中通领域应用非常广泛。受国际电信联盟(ITU)和联邦通信委员会(FCC)相关规定的限制,VSAT需要采用扩频等低功率谱密度的通信方式。由于扩频的CDMA系统是干扰受限的系统,多个用户之间的相互干扰是降低系统频谱效率的重要因素。为进一步提高系统频谱利用效率,本文提出了一种基于BP的多用户检测与LDPC译码联合迭代的方法,可以有效降低异步CDMA系统中的多址干扰,仿真表明该方法在保证性能的前提下,能够有效的降低处理时间,易于工程实现。更多还原

【Abstract】 Satellite communication on-the-move system is the important field of the highest demands and great development in the satellite communication,which has an extremely broad development prospects in both areas of the military and civilian.Very Small Aperture Terminal(VSAT) is widely used in satellite communication on-the-move systems.Restrained by the strict limits on the off-axis emissions from the satellite terminal imposed by ITU and FCC,spread spectrum is a natural choice.However,CDMA system with spread spectrum is interference limited,in which the mutual interference is the most important factor to reduce the spectrum efficiency.For higher spectrum efficiency,in this paper,a joint chip-level iterative algorithm for CDMA multiuser detection and LDPC decoding based on Belief Propagation(BP) for satellite system is developed.Simulation results shows that in order to achieve similar performance,the proposed algorithm needs less iterative times comparing with the conventional iterative algorithm,which means less processing time,more suitable for engineering implementation.更多还原