Title :
On TCM schemes transparent to constant phase and frequency shifts
Author :
Liu, Yow-Jong ; Biglieri, Ezio
Author_Institution :
GTE Lab., Waltham, MA, USA
fDate :
30 Sep-3 Oct 1990
Abstract :
The problem of digital transmission over a channel with phase ambiguity generated by a constant phase shift or (Doppler) frequency shift is considered. To remove this phase ambiguity differential encoding/decoding techniques are used in systems with combined modulation and coding, provided that the transmitted sequence is transparent to the phase rotations of the signal space. Necessary and sufficient conditions for a trellis-coded modulation (TCM) scheme to be fully transparent rotationally invariant are derived. Procedures for the design of fully transparent phase-invariant trellis codes (PIC), Doppler-invariant trellis codes (DIC), and phase/Doppler-invariant trellis codes (PDIC) are proposed. Examples are given to clarify the design procedures
Keywords :
Doppler effect; decoding; encoding; modulation; telecommunication channels; Doppler frequency shift; Doppler-invariant trellis codes; TCM; channel; coding; constant frequency shift; constant phase shift; differential decoding; differential encoding; digital transmission; modulation; necessary conditions; phase ambiguity; phase rotations; phase/Doppler-invariant trellis codes; signal space; sufficient conditions; transparent phase-invariant trellis codes; trellis-coded modulation; Convolutional codes; Decoding; Digital modulation; Doppler shift; Frequency synchronization; Laboratories; Modulation coding; Phase modulation; Power system reliability; Sufficient conditions;
Conference_Titel :
Military Communications Conference, 1990. MILCOM '90, Conference Record, A New Era. 1990 IEEE
Conference_Location :
Monterey, CA
DOI :
10.1109/MILCOM.1990.117447
