Soft-In Soft-Output Detection in the Presence of Parametric Uncertainty via the Bayesian EM Algorithm
© Gallo and Vitetta 2005
Received: 30 April 2004
Published: 28 April 2005
We investigate the application of the Bayesian expectation-maximization (BEM) technique to the design of soft-in soft-out (SISO) detection algorithms for wireless communication systems operating over channels affected by parametric uncertainty. First, the BEM algorithm is described in detail and its relationship with the well-known expectation-maximization (EM) technique is explained. Then, some of its applications are illustrated. In particular, the problems of SISO detection of spread spectrum, single-carrier and multicarrier space-time block coded signals are analyzed. Numerical results show that BEM-based detectors perform closely to the maximum likelihood (ML) receivers endowed with perfect channel state information as long as channel variations are not too fast.
Keywordsexpectation-maximization algorithm soft-in soft-out detection fading channels space-time coding OFDM
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