摘要
现有的MIMO系统中,当多用户在同一信道同时与AP通信时,存在多用户干扰的问题。本文提出1种基于原模图LDPC码的多用户MIMO干扰消除的方法,解决了现有MIMO局域网吞吐量受限于基站天线数的问题,使多用户可以在同一信道同时通信。该方法将原模图LDPC码应用到多用户MIMO系统中,通过对发送数据流的信道编码,增强空间复用信息的抗干扰能力和纠错能力。其核心思想是:利用多用户信道衰落的差异,AP(接入节点)接收端优先提取信号最强的用户信息,将其他用户信号和信道噪声视为新的噪声,通过迭代译码算法,AP接收端可以获得所有共信道用户的发送信息。在多用户干扰信道,此方法能够提供更高的复用增益。仿真结果表明,与直接提取用户信息相比,在平坦瑞利衰落信道应用本方法提取用户信息可分别得到2～20dB的编码增益,通信容量增加了2倍。
In the current MIMO systems, there exists multi-user interference when multiple users communicate with access points （AP） simultaneously in the same channel. In this paper, a new multi-user MIMO interfer- ence cancellation method based on protograph LDPC codes was proposed to solve the problem that the through- put of in the existing MIMO LANs is limited by the number of antennas at base stations. Protograph LPDC codes were applied in the multi-user MIMO systems and the transmitted data flow was encoded to heighten the noise immunity and error correcting abilily of multiplexing information in the space. The core ideas of the pro- posed method are as follows： Depending on the differences in multi-user channel fading, the AP receiving ter- minal gives priority to decoding the strongest user signal and takes the other user signals and channel noises as new noises; with the iterative decoding algorithm, the receiving terminal can obtain the transmitted informa- tion of all co-channel users. The proposed method can provide higher multiplexing gains in multi-user interfer- ence channels. Experimental simulation yields 2-20dB coding gain and two times of communication capacity in the Rayleigh flat-fading channel as compared with the methed of directly extracting user information.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2013年第2期37-43,共7页
Journal of the China Railway Society
基金
北京市自然科学基金(4102050)
