Title :
Performance of trellis codes for primary rate ISDN
Author :
Khalifa, Ahmed R. ; Ahamed, Syed V.
Author_Institution :
Al-Azhar Univ., Cairo, Egypt
Abstract :
Trellis code combines channel coding and modulation techniques for data transmission over band limited channels. Theoretically, it achieves significant coding gains over conventional uncoded multilevel modulation without compromising bandwidth efficiency. The authors study the effect of trellis encoding algorithms, and evaluate their effectiveness for the carrier serving area (CSA) loop environment in the presence of imperfect echo cancelers, for primary rate ISDN application. A basic methodology for the simulation of trellis codes for QAM clusters is utilized. The effect of trellis codes for 16and 64-QAM is studied. Results for the coded 16- and 64-QAM constellations for three typical loops with 60 dB of echo cancellations are presented. The effect of trellis codes on the entire PCSA (pseudo CSA) loop population is also presented
Keywords :
ISDN; channel coding; echo suppression; quadrature amplitude modulation; subscriber loops; trellis codes; 16-QAM; 64-QAM; QAM clusters; band limited channels; carrier serving area loop environment; channel coding; data transmission; echo cancellation; imperfect echo cancelers; modulation techniques; primary rate ISDN; trellis codes; trellis encoding algorithms; Bandwidth; Code standards; Convolutional codes; Decision feedback equalizers; Echo cancellers; ISDN; Maximum likelihood decoding; Modulation coding; Quadrature amplitude modulation; Wire;
Conference_Titel :
Communications, 1994. ICC '94, SUPERCOMM/ICC '94, Conference Record, 'Serving Humanity Through Communications.' IEEE International Conference on
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-1825-0
DOI :
10.1109/ICC.1994.368808
