Abstract
A trellis coded 4-ary Pulse Amplitude Modulation
(4-PAM) is presented, where the encoding algorithm is derived
from Distance Preserving Mapping (DPM) algorithm. In this
work, we modify the DPM algorithm for 4-PAM and obtain a
new construction for mapping binary sequences to permutation
sequences, where the permutation sequences are obtained by
permuting symbols of a 4-PAM constellation. The resulting
codebook of permutation sequences formed this way are termed
mappings. We also present several metrics for assessing the
performance of the mappings from our construction, and we show
that a metric called the Sum of Product of Distances (SOPD) is
the best metric to use when judging the performance of the
mappings. Finally, performance results are presented, where the
mappings from our construction are compared against each other
and also against the conventional mappings in the literature.
Index Terms—Distance-preserving mappings, Hamming distance,
Euclidean distance, Pulse Amplitude Modulation.