摘要：Rake接收机在1958年首先由Price 和Green提出，这是扩频通信系统的关键技术。在本毕业论文中，Rake接收机的信号功率是已知的。信道脉冲响应被建模为复杂且不确定的高斯随机向量。使用贝叶斯理论，无需导频和信道估计即可实现。新的Rake接收机使用观测数据获得信道脉冲响应的信息，逐步准确地估计信道脉冲响应的平均值和协方差，最后解决权重。从理论推导出来，我们可以看到新的Rake接收机具有较低的复杂度，适用于工程实现。从仿真结果可以看出，与使用最大比合并（MRC），具有奇异值分解算法（SVD）的Rake接收机和具有基于快速近似幂迭代子空间跟踪算法（FAPI）的Rake接收机的All-Rake接收机相比，新的Rake接收机的误码率性能已经大大提高。

关键词  反多径衰落，贝叶斯，CDMA，Rake接收机

毕业设计说明书外文摘要

Title   A Bayesian Approach to Adaptive Rake Receiver 

Abstract：Rake receiver was first proposed by Price and Green in 1958. It is widely used in code pision multiple access (CDMA) communication system for anti-multipath fading. In this paper, signal power is known. The channel impulse response is modelled as a complex and uncertain Gaussian random vector. Using Bayesian theory, working without pilot and channel estimation both can be achieved. The new Rake receiver uses observed data to obtain information of the channel impulse response, progressively and accurately estimates the mean values and covariance of the channel impulse response, and finally solves for the weights. From the theoretical derivation, we can see the new Rake receiver has low complexity, which is suitable for engineering realization. From the simulation results, we can see that the bit error rate performance of the new Rake receiver has been greatly improved compared to the All-Rake receiver with maximal-ratio combing (MRC), Rake receiver with Singularly Valuable Decomposition (SVD), and Rake receiver with fast approximated power iteration algorithm (FAPI).

Keywords  anti-multipath fading, Bayesian, CDMA, Rake receiver

目   次

1  绪论 3

1.1 研究的目的与意义 3

1.2 国内外研究现状 3

1.3 论文的内容安排 5

2 扩频通信系统与Rake接收机 6

2.1 引言 6

2.2 扩频通信的理论基础 6

2.3 扩频信号的产生和调制技术 10

2.4  扩频信号的解扩和解调 11

2.5  本章小结 20

3 贝叶斯Rake接收机 21

3.1 引言 21

3.2  贝叶斯Rake接收机 22

3.3  贝叶斯Rake接收机递归算法 25

3.4  贝叶斯Rake接收机仿真实验 29

3.5  本章小结 31

结  论 32

致  谢 33