采用自适应调制的空间复用系统研究

The Study on Spatial Multiplexing System Employing Adaptive Modulation

针对采用V-BLAST检测算法的空间复用系统,提出新的自适应调制方案.传统自适应调制依据的是接收天线处检测到的信噪比,而提出的自适应调制根据的是V-BLAST检测算法中多次串行迭代检测后检测该数据流时的实际比特信噪比,由于多次迭代后未检信号的信噪比会升高,可以在满足目标误比特率要求的前提下尽可能采用较高的调制制式来提高频谱效率.仿真结果表明,改进型自适应调制算法对应的频谱效率明显优于传统自适应调制算法.

A novel adaptive modulation ,scheme is proposed for the spatial multiplexing system employing V-BLAST detection algorithm. This adaptive algorithm is adapted according to the actual post-proeessing bit SNR after a series of iterative detection, while conventional one is based on simple preproeessing SNR levels measured at the antennas. Because the SNR of undetected bit stream will become higher by means of successive interference cancellation, higher modulation mode can be selected to operate at a given target BER, thus the higher spectral efficiency can be achieved. The simulation results demonstrate that the proposed adaptive modulation algorithm can get the higher spectral efficiency than conventional one.