相关信道下MIMO-OFDM系统的各态历经容量公式  

Ergodic capacity formula for MIMO-OFDM systems under correlated fading channels

作　　者：庞继勇[1] 李建东[1] 杨克虎[2] 

机构地区：[1]西安电子科技大学综合业务网理论与关键技术国家重点实验室,陕西西安710071 [2]西安电子科技大学雷达信号处理重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2006年第4期563-567,575,共6页Journal of Xidian University

基　　金：国家自然科学基金和微软亚洲研究院联合资助项目(60372048);国家自然科学基金重大项目(60496316);国家"863"计划课题(2005AA123910);高等学校优秀青年教师教学科研奖励计划;教育部科学技术研究重点项目(104171)

摘　　要：通过将离散频域表示的信道冲击响应矩阵等效为由多径间相关和收发两端空域相关三者所确定的“Kronecker”相关信道模型,推导出频率选择性瑞利衰落信道中MIMO-OFDM系统在同时具有这3种相关性条件下的各态历经容量公式.该公式为评估各种相关性对于MIMO-OFDM系统容量的影响提供了一个简单而有效的工具.在多径间相互独立时,各态历经容量的表达式比较简单;当多径间相关时,各态历经容量可进一步表示为一个积分形式,并由Monte Carlo仿真给出了3种相关性、多径时延扩展和子载波数目对各态历经容量的影响.An explicit formula for the ergodic capacity of orthogonsl frequency division multiplexing （OFDM）-based multiple-input multiple-output（MIMO） systems under correlated frequency selective Rayleigh fading channels is derived, by simplifying the channel response matrix in the frequency domain into the so-called “Kronecker” model composed of three kinds of correlations, i. e., multipath tap gain correlation and spatial fading correlations at both the transmitter and the receiver. The derived formula is very simple and convenient for one to estimate the effects of all three kinds of correlations on MIMOOFDM capacity. If taps are independent, there exists a simple expression for the ergodic capacity. In the case of tap correlation, the capacity formula could be further given in an integral expression. Both the validity of the new formula is verified and the effects of correlations, delay spread as well as the number of subcarriers on the ergodic capacity are evaluated via Monte Carlo simulations.

关 键 词：多输入多输出 正交频分复用 KRONECKER乘积 各态历经容量 信道相关性 

分 类 号：TN911.22[电子电信—通信与信息系统]