A. Said et Jb. Anderson, BANDWIDTH-EFFICIENT CODED MODULATION WITH OPTIMIZED LINEAR PARTIAL-RESPONSE SIGNALS, IEEE transactions on information theory, 44(2), 1998, pp. 701-713
Citations number
33
Categorie Soggetti
Computer Science Information Systems","Engineering, Eletrical & Electronic","Computer Science Information Systems
We study the design of optimal signals for bandwidth-efficient linear
coded modulation, Recent results show that for linear channels with in
tersymbol interference (ISI), reduced-search decoding algorithms have
near-maximum-likelihood error performance, but with much smaller compl
exity than the Viterbi decoder. Consequently, the controlled ISI intro
duced by a lowpass filter can be practically used for bandwidth reduct
ion, Such spectrum shaping filters comprise an explicit coded modulati
on, for which we seek the optimal design, We simultaneously constrain
the bandwidth and maximize the minimum Euclidean distance between sign
als, We show that under quite general assumptions the problem can be f
ormulated as a linear program, and solved with well-known efficient op
timization techniques, Numerical results are presented, and the perfor
mance of the optimal signals, measured by their combined bandwidth and
noise immunity, is analyzed, The new codes are comparable to set-part
ition (TCM) trellis codes, Tests of an M-algorithm decoder confirm thi
s and show that the performance occurs at small detection complexity.