DocumentCode :
2165130
Title :
Improving the speed and performance of adaptive equalizers via transform based adaptive filtering
Author :
Shamma, Mohammed A.
Volume :
2
fYear :
2002
fDate :
2002
Firstpage :
1301
Abstract :
Adaptive equalizers are widely used in many communication systems where the channel frequency response characteristics are either time varying or unknown such as the case in wireless and dial up telecommunication networks where the communication channel constantly change due to the different packet routes and switching that takes place, as well as due to the changes in the RF propagation. This work presents an enhancement to the well known linear adaptive equalizer by means of the transform least mean squares (TLMS) algorithms which exploit the usefulness of transforms such as the discrete wavelets transform (DWT), discrete cosine transform (DCT), discrete Hartley transform (DHT), and discrete Fourier transform (DFT). The use of the TLMS is compared to the standard least mean squares (LMS) algorithm and the advantages are shown via time domain simulations and eigenvalue ratio computations of the maximum over minimum eigenvalue of the autocorrelation matrix of the transform domain input signal for each of the transforms studied. Among those advantages are faster convergence speeds, and better time and frequency characteristics.
Keywords :
adaptive equalisers; adaptive filters; correlation methods; discrete Fourier transforms; discrete Hartley transforms; discrete cosine transforms; discrete wavelet transforms; filtering theory; matrix algebra; DCT; DFT; LMS algorithm; RF propagation; TLMS algorithms; autocorrelation matrix; channel frequency response characteristics; convergence speed; dial up telecommunication networks; discrete Fourier transform; discrete Hartley transform; discrete cosine transform; discrete wavelets transform; east mean squares algorithm; eigenvalue ratio; linear adaptive equalizer; maximum eigenvalue; minimum eigenvalue; packet routes; packet switching; time domain simulations; time varying channels; transform based adaptive filtering; transform domain input signal; transform least mean squares algorithms; Adaptive equalizers; Adaptive filters; Communication channels; Discrete Fourier transforms; Discrete cosine transforms; Discrete wavelet transforms; Eigenvalues and eigenfunctions; Fourier transforms; Frequency response; Time varying systems;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Digital Signal Processing, 2002. DSP 2002. 2002 14th International Conference on
Print_ISBN :
0-7803-7503-3
Type :
conf
DOI :
10.1109/ICDSP.2002.1028332
Filename :
1028332
Link To Document :
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