@CONFERENCE\{IMM2007-05381,
    author       = "M. Hansen and L. P. B. Christensen and O. Winther",
    title        = "On Sphere Detection and Minimum-phase Prefiltered Reduced-State Sequence Estimation",
    year         = "2007",
    month        = "nov",
    booktitle    = "{IEEE} Globecom",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/5381-full.html",
    abstract     = "In 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."
}