CDMA系统智能天线盲自适应波束形成

Blind adaptive beamforming for smart antenna in CDMA systems

给出了基于最大化信号对干扰和噪声的功率比 (MSINR)准则的盲自适应波束形成在线递推算法 ,旨在提高DS CDMA系统中智能天线的性能。将MSINR准则转化为一种新的等价的无约束准则函数 ,通过最大化此准则函数来在线估计最优波束形成向量。算法直接利用了DS CDMA系统解扩前和解扩后的观测信号 ,无须训练序列。通过在线迭代估计 ,降低了计算波束权值的复杂度。不同通信环境中的仿真结果表明 ,该算法具有较高的估计精度和很好的抗多址干扰能力。

An on-line iterative blind adaptive algorithm based on the maximum signal-to-(interference plus noise) ratio (SINR) criterion is proposed to improve the performance of the smart antenna in DS-CDMA systems. A novel unconstrained criterion equivalent to MSINR criterion is proposed. By maximizing the unconstrained criterion, the optimal beamforming vector can be estimated. The algorithm directly utilizes un-despreaded and despreaded signal vectors without any reference signals. Employing the method of the on-line iterative estimation, the computation complexity of estimating the beamforming vector is lowered greatly. Simulation results in various signal environments show that the algorithm has excellent estimation accuracy and capability of suppressing multiple access interference (MAI).