Abstract
An approximate maximum likelihood (ML) method for joint estimation of time delays and directions- of-arrivals (DOA's) for the direct-sequence code-devision multiple-access (DS-CDMA) systems over the multipath Rayleigh fading channels is developed. The proposed estimation scheme is developed by modeling the known training sequence of the desired user as the desired signal and the multiple access interferences (MAI)-plus-AWGN as unknown colored Gaussian noise uncorrelated with the desired signal. An efficient iterative algorithm for estimating channel parameters (the time delays and DOA's of multipath signals) is proposed to reduce computational complexity. The algorithm transforms the multi-dimensional maximization problem into two simple one-dimensional (1-D) maximization problems based on an iterative scheme. Analytical and simulation results are presented to illustrate the performance in comparison with the Cramer-Rao bounds (CRBs). It is shown that the proposed algorithm is near-far resistant for both time delay and DOA estimation and little performance loss is observed in comparison with the CRBs at reasonable SNRs.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1436-1440 |
| Number of pages | 5 |
| Journal | IEEE International Conference on Communications |
| Volume | 5 |
| State | Published - 2001 |
| Event | International Conference on Communications (ICC2001) - Helsinki, Finland Duration: Jun 11 2000 → Jun 14 2000 |
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering