Title :
Blind equalization using higher order cumulants and neural network
Author :
Mo, Shaomin ; Shafai, Bahram
Author_Institution :
AT&T Bell Labs., Holmdel, NJ, USA
fDate :
11/1/1994 12:00:00 AM
Abstract :
The paper develops a new method to achieve blind equalization in digital communication for linear finite impulse response (FIR) systems, whether the systems are minimum phase or not. This new approach divides the problem into two parts. First, it employs the characteristic of the linear system to estimate the original channel based on the fourth-order cumulants instead of time samples of the channel output. Thus, nonminimum phase channels can be handled. Second, it utilizes the nonlinear characteristics of the neural network to build an inverse system (equalizer) for the original channel. This is done by using the estimated channel as a reference system to train the neural network. The neural network helps the equalizer to reduce the degree of model uncertainty and makes the equalizer resistant to additive noise. Taking the advantages of both linear and nonlinear systems, this new scheme works well for both stationary and nonstationary cases and leads to good equalization results
Keywords :
FIR filters; Gaussian noise; backpropagation; digital communication; equalisers; intersymbol interference; neural nets; parameter estimation; signal reconstruction; telecommunication channels; white noise; additive noise; blind equalization; digital communication; fourth-order cumulants; higher order cumulants; inverse system; linear finite impulse response systems; minimum phase; model uncertainty; neural network; nonlinear characteristics; nonminimum phase channels; nonstationary cases; reference system; stationary cases; Additive noise; Blind equalizers; Decision feedback equalizers; Digital communication; Finite impulse response filter; Linear systems; Multi-layer neural network; Neural networks; Signal reconstruction; Uncertainty;
Journal_Title :
Signal Processing, IEEE Transactions on