Title :
Analog multiplierless LMS adaptive FIR filter structures
Author :
Huang, Qin ; Moschytz, George S.
Author_Institution :
Inst. for Signal & Inf. Process., Swiss Federal Inst. of Technol., Zurich, Switzerland
fDate :
12/1/1993 12:00:00 AM
Abstract :
Two adaptive FIR filter configurations are proposed for implementing the LMS algorithm with no analog delay elements or multipliers. The first uses a linear feedback shift register (LFSR) to generate pseudorandom binary sequences for applications where white noise has been traditionally used. The binary signals are delayed by a shift register and multiplied by on/off switching so that the resulting structure is free of analog delay lines and multipliers. For applications where inputs are colored, the second configuration uses a sigma-delta modulator as a front-end for converting the adaptive filter´s input into a binary sequence. Such a filter tends to adapt itself into a low-pass characteristic to remove the high-frequency noise due to the modulator
Keywords :
active filters; adaptive filters; analogue processing circuits; binary sequences; delta modulation; feedback; least squares approximations; shift registers; LMS adaptive filter; LMS algorithm; adaptive FIR filter; analog multiplierless structures; colored input; high-frequency noise; linear feedback shift register; low-pass characteristic; pseudorandom binary sequences; sigma-delta modulator; white noise; Adaptive filters; Band pass filters; Convergence; Filtering theory; Finite impulse response filter; Hardware; Least squares approximation; Random sequences; Voltage; White noise;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on