扩频通信中多径信道参数估计和跟踪方法

利用ＣＤＭＡ用户在使用ＢＰＳＫ调制信号时的多径信道模型，根据ＰＮ码的特点先用最大似然法估计出信道的冲激响应矢量，再进一步估计出ＲＡＫＥ接收机所需的各多径延和衰减系数等参数，分析和计算结果表明，此方法具有速度快，计算量小和精度高等优点。

The Estimation and Tracking of the Parameters the Spread-spectrum Multipath Channel

The model of channel with multipath transmission for CDMA user who are using BPSK modulated signals is used. By using the characteristics of PN code and the maximum-likelihood method, the channel im pulse response vector can be estimated, then all of the multipath delays and attenuation weights can be obtained. These parameters are needed for RAKE receiver to deal with the multipath signals. Results show this method has the advantage of high accuracy, fast speed, and small computation volume as well. Furthermore. the extended Kalman filter(EKF) is used to estimate simultaneously the changes of all parameters such as multipath delays and attenuation weights. It is proved that the needs of realtime tracking of the channel parameters in high accuracy and fast computational velocity can be satisfied by using EKF.