Abstract
An adaptive iterative (turbo) decision-feedback equalizer (DFE) for channels with intersymbol interference (ISI) is presented. The filters are computed directly from the soft decisions and received data to minimize a least-squares (LS) cost function. Numerical results show that this method gives a substantial improvement in performance relative to a turbo DFE computed from an exact channel estimate, assuming perfect feedback. Adaptive reduced-rank estimation methods are also presented, based on the multistage Wiener filter (MSWF). The adaptive reduced-rank turbo DFE for single-input/single-output channels is extended to multiple-input/multiple-output (MIMO) channels with ISI and multiple receive antennas. Numerical results show that for MIMO channels with limited training, the reduced-rank turbo DFE can perform significantly better than the full-rank turbo DFE.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2789-2800 |
| Number of pages | 12 |
| Journal | IEEE Transactions on Wireless Communications |
| Volume | 4 |
| Issue number | 6 |
| DOIs | |
| State | Published - Nov 2005 |
Funding
Manuscript received August 16, 2003; revised April 23, 2004; accepted September 20, 2004. The editor coordinating the review of this paper and approving it for publication is L. Vandendorpe. This work was supported by the Northwestern–Motorola Center for Communications, and by the U.S. Army Research Office under Grant DAAD19-99-1-0288. This paper was presented in part at the IEEE Military Communications (MILCOM) Conference, Anaheim, CA, October, 2002.
Keywords
- Adaptive filters
- Multiple-input/multiple-output (MIMO) channels
- Space-time processing
- Turbo equalization
ASJC Scopus subject areas
- Computer Science Applications
- Electrical and Electronic Engineering
- Applied Mathematics