Channel estimation for chip‐level Alamouti coded multi‐rate CDMA: blind subspace algorithms and performance analysis
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Bibliographic record
Abstract
Abstract In this work we consider the problem of blind channel estimation for the downlink of a variable spreading gain (VSG) multi‐rate code‐division‐multiple‐access (MR CDMA) system which uses the orthogonal space‐time block coding (STBC) proposed by Alamouti. In contrast to traditional symbol‐level STBC CDMA systems, we consider a chip‐level ST block coding system for which we derive a simple subspace‐based blind channel estimation method. For the derived algorithm we investigate the necessary and sufficient conditions for the channel to be uniquely identifiable up to a complex multiplicative constant. We also analyse the behaviour of the channel estimation algorithm as a function of the data samples utilised, establishing its unbiasedness and providing a closed‐form expression for the mean‐square‐error (MSE) as well as the Cramer—Rao bound (CRB) for the channel estimation performance. Copyright © 2007 John Wiley & Sons, Ltd.
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Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
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Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
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