DocumentCode :
428025
Title :
Adaptive interference suppression in multiuser OFDM
Author :
Venkataraman, Vishwanath ; Shynk, John J.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., Santa Barbara, CA, USA
Volume :
1
fYear :
2004
fDate :
26-29 Sept. 2004
Firstpage :
655
Abstract :
Orthogonal frequency-division multiplexing (OFDM) with multiple access has been proposed for future wireless networks because of its resistance to channel multipath effects and narrowband interference. In a multiuser OFDM (MU-OFDM) network employing frequency-division multiple-access (FDMA), users of a base station operate on different subcarriers. As the number of users increases in such a network, the cochannel interference caused by users from other base stations also increases, and thus the receiver might require multiple antennas to reject this interference. We present a blind interference suppression system for MU-OFDM that is based on the blind constant modulus (CM) array. The subcarriers of each antenna element have independent weights, so that s can be placed in the directions of the interference affecting each subcarrier. Thus, using an M-element CM array, the receiver can more than M-1 partially overlapping cochannel interferers of different power levels and modulation formats. A constrained CM array that keeps the blind algorithm from capturing an interferer instead of the signal of interest is also described.
Keywords :
OFDM modulation; adaptive signal processing; antenna arrays; array signal processing; cochannel interference; frequency division multiple access; interference suppression; mobile radio; multipath channels; multiuser channels; FDMA; adaptive interference suppression; blind constant modulus array; blind interference suppression; cochannel interference; constrained constant modulus array; frequency-division multiple-access; mobile users; multipath effects; multiple antennas; multiuser OFDM; narrowband interference; orthogonal frequency-division multiplexing; Base stations; Directive antennas; Frequency division multiaccess; Frequency division multiplexing; Interchannel interference; Interference suppression; Narrowband; OFDM; Receiving antennas; Wireless networks;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Vehicular Technology Conference, 2004. VTC2004-Fall. 2004 IEEE 60th
ISSN :
1090-3038
Print_ISBN :
0-7803-8521-7
Type :
conf
DOI :
10.1109/VETECF.2004.1400089
Filename :
1400089
Link To Document :
بازگشت