空时分层结构码分多址系统的上行多用户检测

Uplink multiuser detection for CDMA systems based on layered space-time coding

针对目前已提出的空时编码结构大多只研究单用户检测这一现状,研究了频率选择性信道下多输入多输出(MIMO)的多用户结构,并提出了一种采用V BLAST空时编码结构码分多址系统的多用户检测算法。基于发射符号的旋转不变特性和奇异值分解,得到了矢量信道冲激响应(VCIR)的盲估计,进而提出了上行信号的多用户检测器。该方法在满足系统对多用户检测性能期望的同时,还能很容易地对算法复杂度进行有效控制。仿真结果表明了该方法的有效性。

Most proposed space-time codec schemes focus on the single-user scenario, which can not be applied in the mobile communication systems directly. Therefore a multi-user multi-input multi-output (MIMO) system in the frequency-selective fading environment is studied. A direct sequence code-division multiple-access (DS-CDMA) scheme using vertical Bell Labs layered space-time (V-BLAST) structure at the user side is proposed. With the assistance of the rotational invariant of the transmitted symbols and the singular value decomposition (SVD), an uplink spatial-temporal multiuser detector is derived based on the blind estimation of the vector channel impulse response (VCIR). This novel scheme has the potential of providing the anticipated multiuser detection (MUD) performance gains with a manageable complexity for the V-BLAST coded CDMA system with the arbitrary antennas. Computer simulation results demonstrate the validity of this proposed scheme.