一种LC_CDMA信道估计方法

A Channel Estimation Method for Long Code CDMA Communication Systems

在 L C_ CDMA通信系统中 ,由于在多径衰落信道下使用了时变扩频码 ,使得信道估计非常困难 ,而对接收机的设计往往需要信道的先验知识。通过利用 L C_ CDMA的输出进行信道估计 ,建立一个CDMA通信系统数学模型和多径频率选择性衰落信道的 FIR滤波器模型 ,用线性神经网络结构的子空间分解方法获得噪声子空间 ,提取噪声分量的信道估计算法 ,并结合信道估计 ,利用噪声子空间与信号子空间正交的特性 ,求解出频率选择性多径信道的响应系数。构建了一个长码条件下的多用户检测器 ,并仿真分析算法的性能。

In the long code CDMA communication system,due to the use of time varying spread code in the multi-path,the channel estimation is more difficult,but the design of the multi-user detectors usually needs to be based on the knowledge of the channel.This paper constructed a long code CDMA communication model and a multi-path frequency-selective fading channel FIR filter model by the channel estimation of LC _ CDMA.Based on the model,this paper proposed a channel estimation algorithm by linear neural networks for noise subspace and analyzed the algorithm performance by a computer simulation.To multi-user detection,this paper also proposed a multi-user detector for long code CDMA based on the channel estimation.