协作多蜂窝无线通信系统预编码技术
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.