Title :
Comparison of hybrid FDMA/CDMA systems in frequency selective Rayleigh fading
Author :
Eng, Thomas ; Milstein, Laurence B.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA
fDate :
6/1/1994 12:00:00 AM
Abstract :
A hybrid FDMA/CDMA scheme operating over a frequency selective Rayleigh fading channel is described and analyzed. The performance of the hybrid system is then compared with that of a wideband CDMA system occupying the same total bandwidth. Both coherent and noncoherent modulation formats are investigated; it is found that, for coherent modulation with a RAKE receiver, wideband CDMA has greater capacity than does the hybrid. However, for the noncoherent modulation formats (either DPSK or square-law detected orthogonal signalling), a hybrid system can have a greater capacity if a high channel error rate can be tolerated. Otherwise, a wideband noncoherent system remains optimal
Keywords :
channel capacity; code division multiple access; fading; frequency division multiple access; modulation; spread spectrum communication; DPSK; RAKE receiver; bandwidth; channel capacity; channel error rate; coherent modulation; frequency selective Rayleigh fading channel; hybrid FDMA/CDMA systems; noncoherent modulation; square-law detected orthogonal signalling; system performance; wideband CDMA system; Bandwidth; Differential quadrature phase shift keying; Error analysis; Fading; Frequency division multiaccess; Modulation; Multiaccess communication; Multipath channels; Signal detection; Wideband;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
