Summary: A ComputationallyEfficient FIR MMSEDFE for
CCI--Impaired Dispersive Channels \Lambda
Naofal AlDhahir, Member IEEE
Fast algorithms for the computation of the FIR MMSE--DFE in the presence of ISI, CCI, and col
ored noise are presented. Substantial reductions in computational complexity are achieved by using
the powerful analytical tools of Cholesky factorization and displacement structure to fully exploit the
structure of the problem. Both symbol--spaced and fractionally--spaced feedforward filters are consid
ered. Finally, we give a detailed complexity evaluation of the proposed algorithm, for scenarios typical
of the U.S. TDMA digital cellular standard IS--54.
Key Words :
Fractionally--spaced decision--feedback equalizer, Co--channel Interference Suppression.
Co--channel interference (CCI) is a performance--limiting impairment in a variety of communi
cation scenarios where spectral efficiency is of primary concern. Examples include narrow--band
mobile digital cellular radio where frequency re--use is employed to make efficient use of the limited
bandwidth available [16, 18, 19] and high--speed transmission on twisted--pair digital subscriber lines
(DSL) sharing the same multi--pair cable [8, 2].
Minimum--mean--square--error decision feedback equalization (MMSE--DFE) has been demon
strated to be an effective receiver structure for combatting CCI on dispersive and noisy channels