Title :
Analysis of incoherent pre-RAKE TDD/DPSK/CDMA wireless portable communications
Author :
El-Khamy, Said E. ; Sourour, Essam E. ; Kadous, Thmer A.
Author_Institution :
Dept. of Electr. Eng., Alexandria Univ., Egypt
Abstract :
Incoherent direct-sequence spread-spectrum code-division multiple-access (CDMA) with differential phase-shift keying (DPSK) modulation is a promising approach for wireless portable communications. The pre-RAKE system is also attracting attention for wireless portable communication in time division duplex applications due to achieving the same multipath diversity of the RAKE receiver but using an ordinary matched filter receiver at the portable unit. In this paper, we study the pre-RAKE system with DPSK modulation for multi-user communications in a Rayleigh fading channel. The system performance is analyzed in a generalized Rayleigh fading multipath channel. Two diversity-combining techniques, namely, maximal ratio combing (MRC), equal gain combing (EGG) and zero forcing equalization (ZFE) are considered Both diversity types are supplemented by selection diversity for the strongest paths in gain. We also consider the effect of imperfect channel estimation on the system performance and compare the results with the case of coherent QPSK pre-RAKE system
Keywords :
Rayleigh channels; code division multiple access; differential phase shift keying; diversity reception; equalisers; land mobile radio; matched filters; multipath channels; parameter estimation; pseudonoise codes; spread spectrum communication; time division multiplexing; RAKE receiver; Rayleigh fading channel; differential phase-shift keying; diversity-combining techniques; equal gain combing; imperfect channel estimation; incoherent direct-sequence spread-spectrum code-division multiple-access; incoherent pre-RAKE TDD/DPSK/CDMA wireless portable communications; maximal ratio combing; modulation; multi-user communications; multipath channel; multipath diversity; ordinary matched filter receiver; selection diversity; system performance; time division duplex applications; zero forcing equalization; Differential phase shift keying; Differential quadrature phase shift keying; Fading; Modulation coding; Multiaccess communication; Multipath channels; Phase modulation; Spread spectrum communication; System performance; Wireless communication;
Conference_Titel :
Radio Science Conference, 1998. NRSC '98. Proceedings of the Fifteenth National
Conference_Location :
Cairo
Print_ISBN :
0-7803-5121-5
DOI :
10.1109/NRSC.1998.711474