Abstract
Transmitter/Receiver motion in mobile radio channels may cause frequency shifts in each received path due to Doppler effects. Most blind equalization methods however, assume time-invariant channels and may not be applicable to fading channels with severe Doppler spread. In this paper, we address the problem of simultaneously estimating the Doppler shift and channel parameters in a blind setup. Both deterministic and stochastic maximum likelihood methods are developed and iterative solutions proposed. The stochastic maximum likelihood solution is based on the modified version of the Baum-Welch algorithm which originated in the study of Hidden Markov Models. The proposed methods are well suited for short data records, appearing in TDMA systems. Identifiability and performance analysis issues are discussed and Cramer-Rao bounds are derived. Also, some illustrative simulations are presented.
| Original language | English |
|---|---|
| Pages (from-to) | 713-717 |
| Number of pages | 5 |
| Journal | Conference Record of the Asilomar Conference on Signals, Systems and Computers |
| Volume | 1 |
| Publication status | Published - 1997 |
| Externally published | Yes |
| Event | Proceedings of the 1996 30th Asilomar Conference on Signals, Systems & Computers. Part 2 (of 2) - Pacific Grove, CA, USA Duration: 3 Nov 1996 → 6 Nov 1996 |