Title :
Channel overloading: improved OCDMA/OCDMA versus PN/OCDMA
Author :
Vanhaverbeke, F. ; Moeneclaey, M.
Author_Institution :
Ghent Univ., Gent, Belgium
fDate :
23 Feb.-1 March 2003
Abstract :
The allowable load in oversaturated CDMA systems is investigated, with multistage successive interference cancellation (m-SIC) and optimum MUltiuser Detection (MUD). We compare the critical load of Pseudo Noise/Orthogonal CDMA (PN/O) and Orthogonal/Orthogonal CDMA (O/O). An extension to scrambled O/O (s-O/O) is introduced, labeled overall-permuted O/O (o-O/O), and its performance is evaluated as compared to s-O/O. Because of the special structure of the signatrue set with O/O, the intrinsic delay of SIC is reduced in O/O as compared to PN/O. For all systems, it is found that with m-SIC the achievable acceptable overload increases with the spreading factor, but O/O clearly outperforms PN/O. With optimum MUD, PN/O outperforms O/O.
Keywords :
channel capacity; code division multiple access; interference suppression; multiuser detection; pseudonoise codes; radiofrequency interference; spread spectrum communication; PN/OCDMA; channel overloading; delay; improved OCDMA/OCDMA; multistage successive interference cancellation; optimum multiuser detection; orthogonal/orthogonal CDMA; oversaturated CDMA systems; pseudonoise orthogonal CDMA; scrambled orthogonal/orthogonal CDMA; signature set; spreading factor; synchronized CDMA system; AWGN channels; Binary phase shift keying; Delay; Interference cancellation; Multiaccess communication; Multiuser detection; Noise cancellation; Random sequences; Silicon carbide; Time division multiple access;
Conference_Titel :
Telecommunications, 2003. ICT 2003. 10th International Conference on
Print_ISBN :
0-7803-7661-7
DOI :
10.1109/ICTEL.2003.1191525
