Channel estimation and equalization in fading

C. Komninakis, C. Fragouli, A.H. Sayed, R.D. Wesel
Conference Record of the Thirty-Third Asilomar Conference on Signals, Systems, and Computers (Cat. No.CH37020)  
This paper addresses the problem of channel tracking and equalization in frequency-selective fading channels. Low-order autoregressive models approximate the channel taps, where each tap is a circular complex Gaussian random process with the typical U-shaped spectrum, and uncorrelated with each other. A Kalman filter tracks the time-varying channel, using the decisions of an adaptive minimum-mean-squared-error decision-feedback equalizer (DFE). The DFE is optimized for decision delay , which
more » ... on delay , which exhibits performance advantages over decision delay for a wide range of channels. The DFE staggered decisions cause the Kalman filter to also track the channel with a delay. The receiver also uses a channel prediction module to bridge the time gap between the Kalman channel estimation and the channel estimates needed for the DFE adaptation. The proposed algorithm offers good tracking behavior, thus allowing for reduction in the amount of training symbols needed to effectively track a time-varying frequency selective channel.
doi:10.1109/acssc.1999.831890 fatcat:iu6r5abo3jcjrdto46a65r7gdm