作为正交频分复用(OFDM)技术与垂直型贝尔实验室分层空时(V-BLAST)结构的结合,OFDM V-BLAST系统能更好地满足新一代宽带移动无线多媒体通信的需求.本文研究OFDM V-BLAST系统在下行频率选择性衰落环境中的解码问题.在阐述了OFDM V-BLAST系统中的联合空频解复用操作之后,本文为OFDM V-BLAST系统提出了一种新颖的半速率旋转不变性联合空频编码方法.通过利用上述旋转不变性,本文为下行频率选择性OFDM V-BLAST系统建立了一种无需了解信道状态信息(CSI)的直接解码算法.大量仿真结果表明了半速率旋转不变性联合空频编码方法的有效性和直接解码算法的性能.

As the combining form of the orthogonal frequency-division multiplexing (OFDM) technique and the vertical Bell Labs layered space-time (V-BLAST) architecture,the OFDM V-BLAST system can better meet the demand of next-generation (NextG) broadband mobile wireless multimedia communications.This paper investigates the decoding problem of the downlink OFDM V-BLAST system under the frequency-selective fading environment.The joint space-frequency demultiplexing operation in the OFDM V-BLAST system is firstly addressed.Successively,one novel half-rate rotational invariance joint space-frequency coding scheme is proposed for the OFDM V-BLAST system.By elegantly exploiting the above rotational invariance property,one direct decoding algorithm without knowing channels state information (CSI) is derived for the downlink frequency-selective OFDM V-BLAST system.Extensive simulation results demonstrate the validity of the novel half-rate rotational invariance joint space-frequency coding scheme and the performance of the direct decoding algorithm.