摘要多蜂窝多用户多输入多输出(MC-MU-MIMO)系统具有频谱利用率高,抗干扰和抗衰落能力强的优点,在未来无线通信领域有着广阔的发展前景。但此系统用户接收机存在多天线和多用户干扰,预编码技术能有效地抑制此类干扰的影响, 提高速率和与误码性能。本文对预编码技术进行了深入的研究,主要研究工作如下: (1)在基站能获取完美信道矩阵时, 通过仿真研究和比较了奇异值分解(singular value decomposition ,SVD)算法、块对角化(block-diagonalization , BD)算法、最大信泄噪比(maximum signal-to-leakage-and-noise ratio , Max-SLNR)算法、最小均方误差 (minimum mean square error , MMSE)算法,仿真表明SVD 提供最优的速率和,但需用户端充分协作,在实际应用中很难实现; (2)考虑了信道状态信息存在误差时,仿真了修正后的 Max-SLNR算法和 MMSE 算法,我们发现随着信道估计误差的增大,系统性能会变差; (3)传统的线性预编码器(Max-SLNR, MMSE和BD)同SVD 相比存在较大的速率和损失,于是本论文提出了一种不需用户端协作基于二次分式积和功率迭代的最大和速率(maximum sum-rate, MSR)预编码器,该预编码器速率和能够高于 Max-SLNR,MMSE 和BD,更逼近SVD。7770
关键词 多蜂窝多用户多输入多输出,预编码器,功率分配,奇异值分解,块对
角化,最大信泄噪比,最小均方误差,信道估计误差,最大和速率算法
Title Pre-coding Methods for Cooperative
Multi-cell Wireless Communication System
Abstract
Multi-cell multi-user multi-input multi-output (MC-MU-MIMO) system has a high
spectrum efficiency, a good ability to combat interference and fading, thus it promises
a broad developing future in the future wireless communications. Since there is
interference at user receivers in this system, pre-coding can effectively reduce the
impact of the interference and can improve the performance of sum-rate and bit error
rate. This paper focuses on the study of pre-coding in MC-MU-MIMO, the main work
is as follow: 1)When base stations can obtain perfect channel matrices, several classic
linear pre-coding algorithms such as singular value decomposition (SVD),
block-diagonalization (BD), minimum mean square error (MMSE) and maximum
signal-to-leakage-and-noise ratio (Max-SLNR) are analyzed and simulated.
Simulations show that the SVD achieves the optimal sum-rate, but it needs full
cooperation among users, this is difficult to be realized in practice; 2)When the error of
channel state information is taken into account, the corrected Max-SLNR algorithm
and MMSE algorithm are simulated,from which we find that with the increasing of
channel estimation error, the performance of the system will become worse; 3)
Considering the traditional pre-coders (Max-SLNR, MMSE and BD) have a serious
sum-rate loss over the SVD, the maximum sum-rate (MSR) pre-coder is proposed. It
combines secondary fraction product with power iterative method and doesn’t need
cooperation among users. It can provide a higher sum-rate than Max-SLNR,MMSE
and BD algorithms,and its sum-rate is close to that of the SVD. 协作多蜂窝无线通信系统预编码技术:http://www.751com.cn/tongxin/lunwen_5845.html