Title :
A CDMA overlay using frequency-diversity spread spectrum
Author :
Papproth, Eckhard ; Kaleh, Ghassan Kawas
Author_Institution :
Ecole Nat. Superieure des Telecommun., Paris, France
Abstract :
The frequency bands currently used by existing narrowband users might be shared with a CDMA spread spectrum overlay system. Thus, the spectrum efficiency is improved providing more capacity for future personal communications networks. Since both narrow- and wide-band signals interfere with each other, a spread spectrum modulation scheme with a good resistance to narrowband interference results in an increased number of acceptable overlay users. We study a frequency-diversity spread spectrum modulation scheme for which optimal detection in the presence of narrowband interference is easy to implement. The acceptable number of overlay users is evaluated and compared to that of conventional direct-sequence spread spectrum modulation schemes with and without interference rejection filters
Keywords :
Gaussian channels; code division multiple access; diversity reception; interference suppression; land mobile radio; modulation; personal communication networks; radio spectrum management; radiofrequency interference; spread spectrum communication; AWGN channel; CDMA overlay; frequency bands; frequency-diversity spread spectrum; interference rejection filters; narrowband interference; narrowband users; optimal detection; personal communications networks; spectrum efficiency; spread spectrum modulation scheme; wideband signals; Detectors; Filters; Frequency; Immune system; Intersymbol interference; Multiaccess communication; Narrowband; Personal communication networks; Spread spectrum communication; Wideband;
Conference_Titel :
Universal Personal Communications. 1995. Record., 1995 Fourth IEEE International Conference on
Conference_Location :
Tokyo
Print_ISBN :
0-7803-2955-4
DOI :
10.1109/ICUPC.1995.497085
