Title :
New rotationally invariant trellis codes with multidimensional signal constellations
Author :
Fu-Quan Wang ; Costello, D.J., Jr.
Author_Institution :
Dept. of Electr. Eng., Notre Dame Univ., IN, USA
fDate :
June 27 1994-July 1 1994
Abstract :
In this paper, the construction of rotationally invariant trellis codes with multidimensional signal constellations is discussed. Linear and nonlinear trellis codes with constraint lengths /spl nu/=2-8 are found using a systematic search. Simulation results show that a /spl nu/=8, linear, 180/spl deg/ rotationally invariant code and a /spl nu/=8, nonlinear, 90/spl deg/ rotationally invariant code achieve 0.4 dB and 0.3 dB real coding gain, respectively, compared with the best /spl nu/=6 code, while the decoding complexity is only four times that of the /spl nu/=6 code. By contrast, the /spl nu/=6 code that was adopted for use in the V.34 28.8-kbit/s modem standard requires sixteen times the complexity of the best /spl nu/=4 code, while the gain is also only about 0.4 dB. Thus, the new /spl nu/=8 codes would be a good choice for use in the V.34 modem standard.<>
Keywords :
decoding; linear codes; modems; search problems; telecommunication standards; trellis codes; 28.8 kbit/s; V.34 modem standard; coding gain; constraint lengths; decoding complexity; linear trellis codes; multidimensional signal constellations; nonlinear trellis codes; rotationally invariant code; rotationally invariant trellis codes; simulation results; systematic search; Code standards; Constellation diagram; Convolutional codes; Decoding; Gain; Modems; Modulation coding; Multidimensional systems; NASA; Viterbi algorithm;
Conference_Titel :
Information Theory, 1994. Proceedings., 1994 IEEE International Symposium on
Conference_Location :
Trondheim, Norway
Print_ISBN :
0-7803-2015-8
DOI :
10.1109/ISIT.1994.395058
