改善V-BLAST/OFDM系统性能的子载波分配研究

Study of Subcarrier Allocation for Improvement of V-BLAST/OFDM System’s Performance

为了提高多用户V-BLAST/OFDM系统的整体性能,我们研究在不同检测方式下的子载波分配准则,并利用矩阵和排序统计的知识对系统性能及取得的多用户分集增益做了定量分析,得到多用户分集增益的数学表达式。仿真结果表明,本文提出的动态子载波分配准则可以有效地利用多用户分集,明显提高V-BLAST/OFDM系统的整体性能。另外,本文与空间分集系统中取得的多用户分集增益进行了仿真比较,表明将基于V-BLAST的多用户OFDM系统与子载波分配相结合更能改善系统的整体性能。

In order to improve the V-BLAST/OFDM systems＇ performance, we study the subcarrier allocation arithmetic with different detection mode and the obtained multi-user diversity gain. Using the theory of the order statistics and random matrices, we analyse the system＇s performance and got the multi-user diversity gain＇s math expression. Simulation results indicate that the proposed subcarrier allocation arithmetic can exploit multi-user diversity effectively and improve the V-BLAST/OFDM systems＇ performance prominently. Moreover, compared to the spatial diversity systems, simulation results also demonstrate that suhcarrier allocation with V-BLAST/OFDM can improve the system performance further.