On channel estimators for iterative CDMA multiuser receivers in flat Rayleigh fading

Müller R (2004)


Publication Status: Published

Publication Type: Conference contribution, Conference Contribution

Publication year: 2004

Book Volume: 5

Pages Range: 2497-2501

Event location: Paris

URI: https://www.scopus.com/inward/record.url?partnerID=HzOxMe3b&scp=4143059331&origin=inward

Abstract

In this work we compare channel estimation algorithms for use in an iterative CDMA receiver in a block fading environment. The receiver consists of a soft multiuser data estimator, a bank of single user decoders, and a multiuser channel estimator. The multiuser data estimator is implemented as parallel interference canceler with unconditional post-MMSE filtering (PIC-MMSE) and the decoder is a soft-in soft-out MAP decoder. In the channel estimator we make use of dedicated pilot symbols and fed back soft-code symbols which are exploited as additional soft pilot symbols when the iterations proceed. We show that using extrinsic information increases the receiver performance significantly compared to using a posteriori information in the feedback for channel estimation. We introduce a linear MMSE (LMMSE) estimator which takes into account the variances of fed back code symbols and compare it to approximations of the least-squares (ALS) estimator and the linear minimum-mean-square-error (ALMMSE) estimator. Performance results are illustrated in terms of bit error rate (BER) and average normalized square error (ANSE) of the channel estimators. They show that the newly proposed LMMSE algorithm outperforms the ALS and ALMMSE algorithms.

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How to cite

APA:

Müller, R. (2004). On channel estimators for iterative CDMA multiuser receivers in flat Rayleigh fading. In Proceedings of the 2004 IEEE International Conference on Communications (pp. 2497-2501). Paris.

MLA:

Müller, Ralf. "On channel estimators for iterative CDMA multiuser receivers in flat Rayleigh fading." Proceedings of the 2004 IEEE International Conference on Communications, Paris 2004. 2497-2501.

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