多径衰落分群子载波MIMO-OFDM系统的性能

Performance of MIMO-OFDM System Based on Subcarrier Grouping in Multipath Fading

在分群空时频MIMO-OFDM系统中使用群化分组各子载波策略,将信道估计的导频序列离散于各独立子群中,由空频两域扩展到空时频域,降低系统编解码以及导频序列设计的复杂度,并推导非精确信道信息下分群空时频MIMO-OFDM系统的成对错误概率上界的闭合表达式.理论分析和计算仿真表明,在衰落信道下等间隔的子载波分群策略,可通过减少运算矩阵的规模降低算法复杂度,且具良好的性能.

In the space-time-frequency-coded MIMO-OFDM system, the scheme of subcarrier grouping is adopted to divide the pilot sequence into independent subchannels, and the channel estimation is extended from the spacefrequency dimensions to the space-time-frequency dimensions, thus reducing the complexity of the system coding/ decoding and the pilot sequence design. Then, the close-form solution to the Chernoff upper bound of the pairwise error probability is derived for the MIMO-OFDM system with imperfect channel information. The results of the theoretical analysis and numerical simulation show that, in the fading channels, the proposed subcarrier grouping scheme with equal intervals is of good performance because it can attain the results with low coding and decoding complexity by reducing the matrix scale.