Title :
Adaptive IIR notch filter with controlled bandwidth for narrow-band interference suppression in DS CDMA system
Author :
Muuma, A. ; Nishimura, Shotaro ; Hinamoto, Takao
Author_Institution :
Graduate Sch. of Eng., Hiroshima Univ., Japan
Abstract :
Suppression of NBI in a DS CDMA system using a fully adaptive IIR notch filter is investigated. An algorithm that requires no gradient signal generating filters for tracking the center frequency of the NBI is proposed. A gradient algorithm for adapting the notch bandwidth coefficient to a value that results in maximum SNR improvement factor and minimum BER is presented. Convergence behaviors of the algorithms are analyzed. Closed-form expressions for SNR improvement factor and BER of the system are derived. Simulations are shown to verify the analyses and compare the performance of the proposed scheme with that of a linear adaptive FIR prediction filter.
Keywords :
IIR filters; adaptive filters; code division multiple access; error statistics; interference suppression; notch filters; spread spectrum communication; DS CDMA system; NBI center frequency tracking; NBI suppression; adaptive IIR notch filter; algorithm convergence behaviors; controlled bandwidth; gradient algorithm; gradient signal generating filters; linear adaptive FIR prediction filter; maximum SNR improvement factor; minimum BER; narrow-band interference suppression; notch bandwidth coefficient; Adaptive control; Adaptive filters; Bandwidth; Control systems; Finite impulse response filter; IIR filters; Interference suppression; Multiaccess communication; Narrowband; Programmable control;
Conference_Titel :
Circuits and Systems, 2003. ISCAS '03. Proceedings of the 2003 International Symposium on
Print_ISBN :
0-7803-7761-3
DOI :
10.1109/ISCAS.2003.1205848
