空时块码与波束形成结合方案及性能分析

The Scheme and Performance Analysis of Combined Beamforming with Space-Time Block Coding

Alamouti空时块码与波束形成相结合的方案只使用了两个功率均分的波束,在很多情况下并非最优。该文提出了新的空时块码与波束形成相结合的方案,新方案能够根据信道互相关矩阵的特征值,展开不超过发射端天线数量的波束,在满足空时块码发射天线数量等于波束数量的条件下,与任意码率空时块码结合。该文还利用Gauss-Chebyshev积分对线性调制下新方案的误符号率进行了性能分析,得出了简单的数值计算表达式。新方案由于同时获得了分集增益和波束形成增益,显著提高了系统的性能。

Combined beamforming with Alamouti space-time block coding may not be optimal under many situations since it only provides two equal power loading beams. A new scheme which combines beamforming with space-time block coding is proposed in this paper. The number of beams the new scheme provides is determined by the channel correlation matrix eigenvalues, and is not more than the number of transmit antennas. Condition on the number of space-time block coding transmit antennas is the same as the number of beams, the new scheme combines beamforming with space-time block coding of any code rate. Ganss-Chebyshev quadrature is used to calculate the symbol error rate of the new scheme for linear modulation and a simple numerical method is derived. The new scheme could improve the performance dramatically by providing diversity gain and beamforming gain simultaneously.