Title :
A combined time-frequency domain beamforming method for OFDM systems
Author :
Seydnejad, Saeid ; Akhzari, Sadegh
Author_Institution :
Dept. of Electr. Eng., Univ. of Kerman, Kerman, Iran
Abstract :
To suppress co-channel interferences in OFDM systems two main schemes namely, the pre-FFT and the post-FFT schemes have been proposed. While pre-FFT is a time-domain beamforming method, post-FFT uses beamforming in frequency domain to suppress directional interferences. It is generally believed that the post-FFT scheme is superior in performance than the pre-FFT method. In this study we first compare these two schemes in pilot-assisted OFDM systems under different channel and system conditions. It is shown that each of these methods shows better performance in a different condition. To take advantage of the strategy of each method, a combined time-frequency method is proposed which produces better results than each of the individual methods while its computational complexity is not much increased compared to the post-FFT scheme. The simple structure of the combined method makes it a suitable choice for interference suppression in the receiver of OFDM systems in practice.
Keywords :
OFDM modulation; array signal processing; cochannel interference; computational complexity; fast Fourier transforms; interference suppression; time-frequency analysis; OFDM systems; cochannel interference suppression; computational complexity; fast Fourier transforms; orthogonal frequency division multiplexing; time-frequency domain beamforming; Antenna arrays; Array signal processing; Computational complexity; Frequency domain analysis; Interference cancellation; Interference suppression; Intersymbol interference; OFDM; Signal to noise ratio; Time frequency analysis; Adaptive Anttena Array; Beamforming; Interference Cancellation; OFDM Systems; Spatial Processing;
Conference_Titel :
Smart Antennas (WSA), 2010 International ITG Workshop on
Conference_Location :
Bremen
Print_ISBN :
978-1-4244-6070-0
Electronic_ISBN :
978-1-4244-6071-7
DOI :
10.1109/WSA.2010.5456435