Title :
Coding for FFH-CDMA Systems - Part II: System Design
Author :
de Deus Junior, G. ; Portugheis, Jaime
Author_Institution :
Escola de Engenharia e de Computacao, Univ. Fed. de Goias, Goiania
Abstract :
For pt.I see ibid., p.Z000319-23, (2006). In part I of this paper, the channel capacity per dimension of a fast frequency-hoping code division multiple-access (FFH-CDMA) with unquantized detector outputs was evaluated and it showed that hard limiting of outputs can significantly degrade capacity. In this paper, a coded FFH-CDMA system whose maximum likelihood receiver works with unquantized outputs is considered. With a matched bit-to-symbol conversion in transmitter, it is shown that a proper design criterion is to maximize symbol Hamming distance. Based on this new criterion, a search algorithm was developed and many good convolutional codes were found. Analytical and simulation results corroborated the effectiveness of the proposed design criterion
Keywords :
Hamming codes; channel capacity; channel coding; code division multiple access; convolutional codes; frequency hop communication; radio receivers; radio transmitters; channel capacity; code division multiple-access; coded FFH-CDMA system; convolutional code; fast frequency-hoping; matched bit-symbol conversion; maximum likelihood receiver; search algorithm; symbol Hamming distance; transmitter; Analytical models; Channel capacity; Convolutional codes; Degradation; Detectors; Frequency conversion; Hamming distance; Maximum likelihood detection; Multiaccess communication; Transmitters;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2006 IEEE Ninth International Symposium on
Conference_Location :
Manaus-Amazon
Print_ISBN :
0-7803-9779-7
Electronic_ISBN :
0-7803-9780-0
DOI :
10.1109/ISSSTA.2006.311786
