Title :
CDMA vs. OFDM for wideband cellular systems
Author :
Peng, Yong ; Mandyam, Giridhar ; Rajan, Dinesh
Author_Institution :
Dept. of Electr. Eng., Southern Methodist Univ., Dallas, TX
Abstract :
In this paper, we compare the downlink transport spectral efficiency (TSE) of DS-CDMA using RAKE receiver, LMMSE receiver, the multiuser cyclic prefix OFDM and zero padding OFDM in wideband cellular systems. The TSE is defined as the distance weighted sum rate per unit bandwidth. It is derived in terms of the output signal to interference noise ratio as the sum of products of bits and the distances over which they are carried per unit time and bandwidth. Analytical expressions for TSE are derived and then numerically evaluated to compare the performance of CDMA and OFDM for different channel conditions. Unlike spectral efficiency, the TSE does not monotonically decrease with base station density. The cell size should be carefully chosen in order to optimize the TSE.
Keywords :
OFDM modulation; broadband networks; cellular radio; code division multiple access; least mean squares methods; radio receivers; spread spectrum communication; DS-CDMA; LMMSE receiver; RAKE receiver; base station density; downlink transport spectral efficiency; multiuser cyclic prefix OFDM; output signal to interference noise ratio; wideband cellular systems; zero padding OFDM; Bandwidth; Downlink; Fading; Interference; Multiaccess communication; Multipath channels; OFDM; RAKE receivers; Signal to noise ratio; Wideband;
Conference_Titel :
Signals, Systems and Computers, 2008 42nd Asilomar Conference on
Conference_Location :
Pacific Grove, CA
Print_ISBN :
978-1-4244-2940-0
Electronic_ISBN :
1058-6393
DOI :
10.1109/ACSSC.2008.5074553
