Bandwidth Efficient Channel Estimation for Multiple-input Multiple-output (MIMO) Wireless Communication Systems: A Study of Semi-blind and Superimposed Schemes
Author | : Aditya K. Jagannatham |
Publisher | : |
Total Pages | : 202 |
Release | : 2007 |
ISBN-10 | : 1109883390 |
ISBN-13 | : 9781109883398 |
Rating | : 4/5 (90 Downloads) |
Book excerpt: Superimposed pilots (SP) are another interesting alternative to reduce the impact of a pilot overhead without a significant increase in computational complexity. We present a study of the mean-squared error (MSE) and throughput performance of superimposed pilots (SP) for the estimation of a MIMO wireless channel. We illustrate a semi-blind scheme for SP based MIMO channel estimation, which improves performance over the traditional mean-estimator. A new result is presented for the worst-case capacity of a communication channel with correlated information symbols and noise. We also address the issue of optimal source-pilot power allocation for SP. In the end we consider the problem of estimation of a time-selective MIMO wireless channel using superimposed pilot (SP) symbols. We demonstrate a scheme for channel estimation based on a complex exponential basis expansion model (CEBEM) approximation of the time-selective wireless channel. We further reduce the MSE of estimation by employing an expectation-maximization (EM) based iterative estimation procedure.