摘要
本文采用最小均方估计方法来获得天线选择系统的不精确信道状态信息(CSI),仅在接收端采用天线选择,且依据最大化SNR准则只选择一根天线。为简化理论分析,考虑2根发射天线M根接收天线的特殊系统。在上述假定的基础上,推导了天线选择系统未知CSI情况下的精确BER表达式以及最佳导频序列长度的选取原则,分析了高斯误差与多普勒频移对BER性能的影响,通过相应的仿真验证了理论分析的正确性。
Recently, the antenna selection （AS） scheme is a hot topic in the region of multiple-input multiple-output （MIMO） systems, due to lower complexity. In the previous research, it is assumed that the channel state information （CSI） is available at the receiver, which, however, is impractical in the wireless transmission environment. During the process of the channel estimation, there exists two-aspect impacts, namely Gaussian errors and Doppler spread, which are caused by Gaussian noise and the speed of mobile, respectively. In this paper, we analyze the performance of AS systems with the imperfect CSI, caused by Gaussian errors and Doppler spread, and derive the exact bit-error-ratio （BER） expression of AS systems in Rayleigh fading channel, using space-time coding transmission scheme. The corresponding simulations are carried out to illustrate the impacts of Gaussian errors and Doppler spread oil the performance of AS systems and to prove the theoretical analysis. The results show that the length of pilot symbols needs a tradeoff under this environment with Doppler spread and Gaussian errors.
出处
《无线通信技术》
2007年第3期12-16,共5页
Wireless Communication Technology
