Iterative Kalman Channel Estimation and Parallel Interference Cancellation for Synchronous CDMA Mobile Radio Channels
碩士 === 長庚大學 === 電機工程研究所 === 90 === In synchronous CDMA system, the traditional two-stage channel estimation (Kalman filter) which was combining multiuser detection (PIC) must use the decorrelator to be first stage structure. We can see the decorrelator has two disadvantages. One is that t...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2002
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/70687898262071168946 |
| Summary: | 碩士 === 長庚大學 === 電機工程研究所 === 90 === In synchronous CDMA system, the traditional two-stage channel estimation (Kalman filter) which was combining multiuser detection (PIC) must use the decorrelator to be first stage structure. We can see the decorrelator has two disadvantages. One is that the complexity of decorrelating filter is raised rapidly when the number of users increases .The other is that decorrelator would have bad effect of noise enhancement. The channel estimate using Kalman filters become more difficult as the noise is enhanced. For solving these problems, we propose a new multistage (iterative) structure where Kalman channel estimation and parallel interference cancellation multiuser detection are conducted in every stage (iteration).we get rid of decorrelating filter and use iterative way to estimate the channel coefficient and multiuser detection. In this situation, the estimation of channel coefficient using Kalman filter won’t be precise. However, we can find that the MAI term is removed gradually while signal is passing through more iteration. At the end of this paper; we compare traditional two-stage detector with our new detector. Simulation result shows that our new proposed detector’s performance be superior to traditional two-stage detector’s performance in the Rayleigh fading channel whether the near far problem exist or nor.
|
|---|