分层空时OFDM系统中多用户检测技术

Multiuser Detection Technique in Layered Space-Time OFDM Systems

提出了一种分层的空时正交频分复用(OFDM)系统结构,将分层的空时分组编码(STBC)应用于OFDM系统中,可在多输入多输出(MIMO)信道上提供分集增益并对抗频率选择性衰落的影响.在接收端采用一种层干扰抑制和干扰隐藏算法以克服多用户间的干扰,在分别解码每一层时抑制其他层的信号,然后在解码其他层时去除前面已解码层所产生的影响.利用该方法可在宽带无线信道上实现多用户可靠的高速通信.仿真结果表明,该系统具有很好的多用户传输性能.

A layered and space-time coded orthogonal frequency division multiplexing (OFDM) system was proposed to provide a diversity gain for the MIMO channels and alleviate the frequency-selective fading effect. Layered space-time block codes (STBC) are applied to OFDM systems, and they can provide diversity gains in MIMO channels and combat the effect of frequency-selective fading. At the receiver, an algorithm of suppressing and canceling interference is employed to overcome the interference among users. Each layer is decoded separately while signals from other layers are suppressed, and then the contributions of the previously decoded layers are subtracted while other layers are decoded. By this approach, reliable and high data rate communication over wideband wireless channels is provided. The simulation results show that the proposed system has good multiuser transmission performance.