Title :
CA-CDMA: channel adapted CDMA for MAI/ISI free burst transmission
Author :
Horlin, François ; Vandendorpe, Luc
Author_Institution :
Commun. & Remote Sensing Lab., Univ. Catholique de Louvain, Belgium
Abstract :
A new precoding scheme is designed that allows the complete orthogonalization of the users in the uplink of a multiuser CDMA system based on burst transmission. With this channel adapted precoding, a simple filter matched to the total user specific impulse responses is able to eliminate all the inter-symbol and the multiple-access interferences present in the received signal. It is shown that an infinity of codes is available to orthogonalize the system. Two objectives are added: a possible recursion in the number of users and a minimization of the average emitted power. The last optimization problem is a complex one. An approximate solution is proposed. It is shown that the system introduced in this paper outperforms the burst system based on a conventional set of codes
Keywords :
adaptive codes; approximation theory; code division multiple access; filtering theory; interference suppression; intersymbol interference; land mobile radio; matched filters; multiuser channels; optimisation; radio links; signal detection; spread spectrum communication; transient response; CA-CDMA; DS-CDMA; MAI/ISI free burst transmission; approximate solution; average emitted power minimization; base station; burst transmission; channel adapted CDMA; channel adapted precoding; channel autocorrelation matrix; channel crosscorrelation matrix; channel impulse response; codes; constant average received power; detector optimization; eigenvalue decomposition; interference suppression; intersymbol interference; matched filter; mobile communications; multiple access system; multiple-access interference; multiuser CDMA system; precoding; received signal; total user specific impulse response; transmitter optimization; uplink; users orthogonalization; Frequency conversion; Frequency domain analysis; H infinity control; Interference constraints; Interference elimination; Intersymbol interference; MIMO; Multiaccess communication; Multiple access interference; Power system modeling;
Conference_Titel :
Communications, 2001. ICC 2001. IEEE International Conference on
Conference_Location :
Helsinki
Print_ISBN :
0-7803-7097-1
DOI :
10.1109/ICC.2001.937116
