An information-theoretic framework for deriving canonical decision-feedback receivers in Gaussian channels

作者：Guess T^*; Varanasi MK

来源：IEEE Transactions on Information Theory, 2005, 51(1): 173-187.

DOI：10.1109/TIT.2004.839506

• decision-feedback equalizer (DFE)
• Gaussian channel
• intersymbol interference (ISI)
• minimum mean-squared error (MMSE)
• multiple access
• prediction
• projection
• spectral factorization
• Wiener filter

A framework is presented that allows a number of known results relating feedback equalization, linear prediction, and mutual information to be easily understood. A lossless, additive decomposition of mutual information in a general class of Gaussian channels is introduced and shown to produce an information- preserving canonical decision-feedback receiver. The approach is applied to intersymbol interference (ISI) channels to derive the well-known minimum mean-square error (MMSE) decision-feedback equalizer (DFE). When applied to the synchronous code-division multiple-access (CDMA) channel, the result is the MMSE (or signal- to- interference ratio (SIR) maximizing) decision-feedback detector, which is shown to achieve the channel sum-capacity at the vertices of the capacity region. Finally, in the case of the asynchronous CDMA channel we are able to give new connections between information theory, decision-feedback receivers, and structured factorizations of multivariate spectra.

• 出版日期2005-1