On Sphere Detection and Minimum-phase Prefiltered Reduced-State Sequence Estimation

Morten Hansen, Lars P. B. Christensen, Ole Winther

AbstractIn this paper, prefiltering techniques for Sphere
Detection (SD) in frequency-selective channels are examined. It
is shown that a link between QL-factorization of the channel
matrix and minimum-phase prefiltering exists. As a result, it is
possible to regard SD as a generalization of traditional reduced-state
sequence estimation, providing a unifying framework for
the two detection methods. It is illustrated how minimum-phase
prefiltering or the Linear Minimum Mean-Square Error Decision
Feedback Equalization (LMMSE-DFE) forward filter is capable
of reducing the complexity of sphere detectors significantly,
while still obtaining near-optimal performance. The significant
reduction in complexity is obtained as prefiltering enables earlier
decision making in SD. Simulations carried out in an EDGE system
confirm that prefiltering leads to a considerable complexity
reduction for sphere detectors.
TypeConference paper [With referee]
ConferenceIEEE Globecom
Year2007    Month November
BibTeX data [bibtex]
IMM Group(s)Intelligent Signal Processing