Title :
A gradient-based joint-detection algorithm for multi-carrier CDMA
Author :
Dammann, Armin ; Raulefs, Ronald ; Auer, Gunther
Author_Institution :
Inst. of Commun. & Navigation, German Aerosp. Center, Oberpfaffenhofen, Germany
fDate :
29 Nov.-3 Dec. 2004
Abstract :
In this paper, we investigate a gradient based joint detection algorithm for MC-CDMA. The algorithm is based on the improvement of a suboptimum initial estimation, which itself can be obtained from an already known low complexity detection algorithm. For the improvement strategy, the algorithm calculates the gradient of the Euclidean distance function between the rebuilt initially estimated transmission signal and the received signal and goes into the direction of the steepest descent in order to find an improved estimation, which is closer to the received signal. Simulation results show, that for 4-QAM modulation and a spreading length of 8, an error performance close to maximum likelihood detection can be achieved with a complexity which is about 26 times lower.
Keywords :
code division multiple access; error statistics; gradient methods; parameter estimation; quadrature amplitude modulation; signal detection; spread spectrum communication; 4-QAM; Euclidean distance function; MC-CDMA; error performance; estimated transmission signal; gradient-based joint-detection algorithm; maximum likelihood detection; modulation; multi-carrier CDMA; received signal; spreading length; steepest descent; suboptimum initial estimation; Detection algorithms; Euclidean distance; Europe; Fading; Maximum likelihood detection; Multiaccess communication; Multicarrier code division multiple access; Navigation; OFDM; Quadrature phase shift keying;
Conference_Titel :
Global Telecommunications Conference, 2004. GLOBECOM '04. IEEE
Print_ISBN :
0-7803-8794-5
DOI :
10.1109/GLOCOM.2004.1379102