Abstract
This paper presents a large-system analysis of the performance of joint channel estimation, multiuser detection, and per-user decoding (CE-MUDD) for randomly spread multiple-input multiple-output (MIMO) direct-sequence code-division multiple-access (DS-CDMA) systems. A suboptimal receiver based on successive decoding in conjunction with linear minimum mean-squared error (LMMSE) channel estimation is investigated. The replica method, developed in statistical mechanics, is used to evaluate the performance in the large-system limit, where the number of users and the spreading factor tend to infinity while their ratio and the number of transmit and receive antennas are kept constant. Joint CE-MUDD based on LMMSE channel estimation is compared to several methods of one-shot channel estimation, i.e., methods that do not utilize decoded data symbols to refine the initial channel estimates, in terms of spectral efficiency. Joint CE-MUDD is found to significantly reduce the rate loss caused by transmission of pilot signals when compared to the receivers based on one-shot channel estimation. This holds particularly for multiple-antenna systems. As a result, joint CE-MUDD can provide significant performance gains compared to the receivers based on one-shot channel estimation.
| Original language | English |
|---|---|
| Article number | 6157088 |
| Pages (from-to) | 1385-1412 |
| Journal | IEEE Transactions on Information Theory |
| Volume | 58 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Mar 2012 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- Channel estimation
- direct-sequence code-division multiple-access (DS-CDMA) schemes
- iterative receivers
- large-system analysis
- linear minimum mean-squared error (LMMSE) estimation
- multiple-input multiple-output (MIMO) systems
- multiuser detection (MUD)
- replica method
- statistical mechanics
- successive decoding