Title :
Steady-state analysis of complex adaptive IIR notch filter and its application to QPSK communication systems
Author :
Hai-Yun Jiang ; Nishimura, Sholaro ; Hinamoto, Takao
Author_Institution :
Fac. of Eng., Hiroshima Univ., Japan
Abstract :
We present a method to analyze the steady-state performance of complex coefficient IIR adaptive notch filter which is useful for the rejection of narrow-band interference from broad-band signals in QPSK spread-spectrum communication systems. The first-order adaptive notch filter based on the simplified gradient algorithm is considered. Analytical expressions have been developed for the conditional mean and variance of the notch filter output. The signal-to-noise ratio improvement factor is also obtained from which the validity of the use of the notch filter can be concluded. Furthermore, by using the results of a first-order filter, the analysis for the cascade structure has been presented. Finally, the results of computer simulations are shown which confirm the theoretical predictions
Keywords :
IIR filters; adaptive filters; adaptive signal processing; cascade networks; filtering theory; interference suppression; notch filters; quadrature phase shift keying; radiofrequency interference; spread spectrum communication; QPSK spread-spectrum communication systems; SNR improvement factor; broad-band signals; cascade structure; complex adaptive IIR notch filter; computer simulations; conditional mean; first-order adaptive notch filter; gradient algorithm; narrow-band interference rejection; notch filter output; signal-to-noise ratio; steady-state analysis; variance; Adaptive filters; Communication systems; IIR filters; Interference; Narrowband; Performance analysis; Quadrature phase shift keying; Signal analysis; Spread spectrum communication; Steady-state;
Conference_Titel :
Signal Processing Proceedings, 2000. WCCC-ICSP 2000. 5th International Conference on
Conference_Location :
Beijing
Print_ISBN :
0-7803-5747-7
DOI :
10.1109/ICOSP.2000.894551
