Saving memory in turbo trellis coded modulation using the sliding window

Abstract

Turbo trellis coded modulation (TTCM) invented by Patrick Robertson adapted the bandwidth efficiency of TCM and iterative decoding of turbo codes and presented better performance without bandwidth expansion [P. Robertson et al., 1996]. But TTCM has a difficulty of implementing a hardware owing to decoder complexity. So, we need efficient scheduling and date storage management. In order to solve this essential problem, we propose a novel TTCM decoder using sliding window technique by using trace back technique, which is popular for realizing long path memories for Virterbi decoders [A.J. Viterbi, Feb. 1998].