一种空时CDMA系统的多用户检测算法

多用户检测技术在实际应用中,难以解决的问题是在减少计算复杂度的同时又提高系统性能。本文针对空时CDMA系统设计了一种多用户检测算法,即附带噪声梯度的最速下降算法。此算法利用变步长迭代的思想实现多用户检测,避免了最小均方误差(MMSE)多用户检测庞大而复杂的求逆运算和固定步长收敛速度较慢的问题。计算机仿真结果表明,在空时CDMA系统中使用本文算法,收敛速度大大增加,同时在保持系统性能的前提下能够容纳较多的用户。

Multiuser Detection Algorithm for Space-Time CDMA System

For implementing Multiuser detection technique, it is difficult to solve the problems how to alleviate the computationally complexity and to increase the performance of system in practice. In this paper, we proposed a new multiuser detection algorithm called the steepest descent with noisy gradient algorithm for space-time CDMA system. The algorithm uses the time-varying iteration to implement multiuser detection in order to avoid huge and complex inverse operation of correlation matrices in MMSE and to solve the slower convergence rate with fixed step size. The simulation results show that the convergence rate of algorithm will increase greatly in Space-time CDMA system. Additionally, not only the performance of system can be kept, but also the capacity of system can be increased greatly.