Title :
Complexity Comparison of OFDM and CDMA for Wideband Communication Systems
Author :
Mailaender, Laurence
Author_Institution :
Bell Labs., Lucent Technol., Holmdel, NJ
Abstract :
It is commonly believed that OFDM systems have a complexity advantage over CDMA. We show that there are two ways for CDMA complexity to remain competitive with OFDM: a multi-channel approach, in which a wideband system is composed of multiple narrow-band systems; and a frequency-domain equalization approach, where the CDMA receiver is based on the same efficient FFT technique used in OFDM. By making some assumptions on receiver design and wireless channel characteristics, we find simple formulas for the required number of complex multiplications per second. MIMO and broadcast systems are considered as special cases.
Keywords :
OFDM modulation; broadband networks; code division multiple access; fast Fourier transforms; frequency-domain analysis; radio receivers; wireless channels; CDMA; FFT technique; OFDM systems; code division multiple access; complexity comparison; fast Fourier transforms; frequency-domain equalization approach; multichannel approach; multiple narrow-band systems; orthogonal frequency division multiplexing; radio receiver design; wideband communication systems; wireless channel characteristics; Bandwidth; Broadcasting; Fading; Least squares approximation; MIMO; Multiaccess communication; Narrowband; OFDM; RAKE receivers; Wideband;
Conference_Titel :
Vehicular Technology Conference, 2006. VTC-2006 Fall. 2006 IEEE 64th
Conference_Location :
Montreal, Que.
Print_ISBN :
1-4244-0062-7
Electronic_ISBN :
1-4244-0063-5
DOI :
10.1109/VTCF.2006.375
