Title :
A coherent dual-channel QPSK modulation for CDMA systems
Author :
Kim, Seong R. ; Lee, Jeong G. ; Hun Lee ; Kang, Byung S. ; Jeong, Jae W.
Author_Institution :
Mobile Commun. Technol. Dept., Electron. & Telecommun. Res. Inst., Taejon, South Korea
fDate :
28 Apr-1 May 1996
Abstract :
For the reverse link in code division multiple access (CDMA) systems, noncoherent 64-ary orthogonal quadrature phase shift keying (QPSK) modulation has been studied intensively since it has been employed by the IS-95 CDMA system. The wideband-CDMA (W-CDMA) personal communications service (PCS) system, which is proposed to the Joint Technical Committee (JTC) by OKI Inc., employed a coherent QPSK modulation. In the W-CDMA system, imperfect estimation of the channel parameters introduces crosstalk between the I- and Q-channels, resulting in a performance degradation. A coherent dual-channel QPSK scheme which eliminates the crosstalk is proposed. Its performance is analyzed numerically for the reverse link of the CDMA system operating over Rayleigh fading channels and compared to W-CDMA QPSK modulation and noncoherent 64-ary orthogonal QPSK modulation. In addition, computer simulation is carried out by means of the COSSAP software tool
Keywords :
Rayleigh channels; broadband networks; code division multiple access; crosstalk; fading; parameter estimation; personal communication networks; quadrature phase shift keying; radio links; CDMA systems; COSSAP software tool; I-channels; IS-95; PCS system; Q-channel; Rayleigh fading channels; W-CDMA system; code division multiple access; coherent QPSK modulation; coherent dual-channel QPSK modulation; computer simulation; crosstalk; imperfect channel parameter estimation; noncoherent 64-ary orthogonal QPSK modulation; orthogonal quadrature phase shift keying; performance analysis; performance degradation; personal communications service; reverse link; wideband CDMA; Crosstalk; Degradation; Fading; Intensity modulation; Modulation coding; Multiaccess communication; Performance analysis; Personal communication networks; Phase modulation; Quadrature phase shift keying;
Conference_Titel :
Vehicular Technology Conference, 1996. Mobile Technology for the Human Race., IEEE 46th
Conference_Location :
Atlanta, GA
Print_ISBN :
0-7803-3157-5
DOI :
10.1109/VETEC.1996.504078
