Title :
Multipath-diversity performance of direct-sequence CDMA using combined M-ary signalling
Author_Institution :
Sch. of Electr. Eng., Univ. of Seoul, South Korea
Abstract :
A combined binary PPM/orthogonal modulation is used in cellular CDMA reverse links in which the multipath-diversity performance for Rayleigh-fading channels is evaluated and compared. As for diversity techniques, equal gain combining (EGC), selection combining (SC), and its generalization, second or third order SC (SC2, SC3), are considered for noncoherent reception. Theoretical analyses show that noncoherent combining loss (NCL) severely degrades the symbol error-rate (SER) performance of EGC when the modulation level M is small, but NCL can be greatly reduced by increasing M⩾16. We also find that SC2 and SC3 significantly improve the SER compared to SC, especially outperforming EGC for small M
Keywords :
Rayleigh channels; cellular radio; code division multiple access; diversity reception; error statistics; multipath channels; multiuser channels; pulse position modulation; spread spectrum communication; telecommunication signalling; DS-CDMA; Rayleigh-fading channels; SER performance; binary PPM/orthogonal modulation; cellular CDMA reverse links; combined M-ary signalling; direct-sequence CDMA; diversity techniques; equal gain combining; modulation level; multipath-diversity performance; noncoherent combining loss; noncoherent reception; second order selection combining; selection combining; symbol error-rate; third order selection combining; AWGN; Diversity reception; Fading; Multiaccess communication; Multipath channels; Performance analysis; Pulse modulation; Rayleigh channels; Signal analysis; Signal processing;
Conference_Titel :
Spread Spectrum Techniques and Applications, 1998. Proceedings., 1998 IEEE 5th International Symposium on
Conference_Location :
Sun City
Print_ISBN :
0-7803-4281-X
DOI :
10.1109/ISSSTA.1998.722484
