摘要
针对多输入多输出(MIMO)高阶正交幅度调制(QAM)系统检测算法使用传统的高斯逼近算法检测复杂度高的问题,研究了其简化算法。MIMO系统高斯逼近算法通过采用树形搜索的办法,对符号后验概率影响大的符号序列加以保留,其算法复杂度与保留符号序列数目成线性,且与调制阶数成指数关系。针对高阶调制QAM符号的特点,用多级映射的方法来进行高斯逼近,新方法结合树形搜索算法的思想,通过将高阶调制QAM符号拆分成多个4-QAM符号,从而可以每次两个比特的计算序列权重,其算法复杂度与调制阶数成线性关系,从而使得高阶调制系统的检测复杂度大大降低。仿真结果表明,多级映射高斯逼近算法能取得接近传统高斯逼近算法的性能。
A simplified detection scheme for multi- input multi- output （MIMO） wireless commumcation systems with high - order QAM modulation is proposed in this paper. For conventional Gaussian approximation（GA） detection, tree- search method is used and only part of transmit symbol combinations contributing significantly to posterior probabilities are retained, having a complexity linear with retained branches number. Due to the property of high- order QAM formats,the new scheme ,called multi -level mapping GA detection, calculates the sequence weight in step of two bits, resulting in a complexity reduction from exponential in the modulation order to linear, compared to basic GA detection, which greatly reduces the complexity for high order modulation MIMO systems. Simulation results show that the multi- level mapping GA can achieve near the performance of GA detection.
出处
《电讯技术》
北大核心
2009年第8期23-26,共4页
Telecommunication Engineering
基金
福建省自然科学基金资助项目(T0850005)
福建省青年人才项目(2007F3066)
