线性离散码系统中基于近似容量分析的发送天线选择算法

Transmit Antenna Selection Based on Approximate Capacity Analysis in Linear Dispersion Codes Systems

为了降低应用线性离散码(LDC)的多输入多输出系统中发送天线选择算法的复杂度,该文利用LDC的线性变换矩阵的酉矩阵参数化性质,推导出了一种考虑LDC矩阵平均影响的近似容量表达式。近似容量表达式不涉及时间扩展的高阶等效信道矩阵的运算,从而基于近似容量的发送天线选择算法可以有效地降低运算复杂度。该文从近似容量出发,给出了最大化近似容量的发送天线选择算法和基于矩阵消元的天线选择算法。近似容量表达式为基于垂直空时分层码(V-BLAST)提出的低复杂度天线选择算法在LDC系统中的直接应用提供了理论支持。仿真结果表明,所提方案具有与最优天线选择算法相近的性能,但具有更低的计算复杂度。基于矩阵消元的天线选择算法与在V-BLAST系统中提出的基于范数和相关性的天线选择算法相比,可以获得更好的分集增益,因而具有更好的误码率性能。

In order to reduce the complexity of transmit antenna selection in Multi-Input and Multi-Output（MIMO） systems using Linear Dispersion Codes（LDC）,an approximate capacity expression considering the average effect of LDC matrix is derived making use of the characterization of unitary-based parameterization of Linear Transformation Matrix for LDC.Transmit antenna selection algorithms based on approximate capacity can lower the complexity efficiently,because the approximate capacity expression does not involve the operations about higher-order equivalent channel matrix extended in time.From the approximate capacity expression,transmit antenna selection algorithms based on maximum approximate capacity and based on matrix elimination are proposed in this paper separately,and meanwhile approximate capacity expression offers theory support for direct use of some transmit antenna selection algorithms proposed in vertical-bell laboratory layered space-time（V-BLAST） systems.Simulation results suggest that the proposed algorithms can approach the performance of optimal antenna selection algorithm with lower complexity.Compared to the norm and correction-based algorithm proposed in V-BLAST systems,the algorithm based on matrix elimination can get better diversity gain,and outperform the former on Bit Error Rate（BER） performance.