Title :
Normalized adaptive decision directed equalization
Author :
Swindlehurst, A. Lee
Author_Institution :
Dept. of Electr. & Comput. Eng., Brigham Young Univ., Provo, UT, USA
Abstract :
It has been observed that with appropriate stepsize normalization, the convergence speed of the constant modulus (CM) algorithm can be dramatically improved. It is shown that if a different normalization strategy is used, one that takes into account the finite alphabet structure of the signals, a standard normalized version of the decision directed equalizer (DDE) is achieved. A simulation example is included to demonstrate the faster convergence of the normalized DDE compared with its constant stepsize implementation and the normalized CM.
Keywords :
adaptive equalisers; adaptive filters; adaptive signal processing; convergence of numerical methods; decision theory; filtering theory; least mean squares methods; LMS adaptive filter; QPSK signal; constant modulus algorithm; constant stepsize; convergence speed; finite alphabet structure; normalized adaptive decision directed equalization; normalized constant modulus; stepsize normalization; Adaptive equalizers; Adaptive filters; Blind equalizers; Constellation diagram; Convergence; Decision feedback equalizers; Error correction; Least squares approximation; Performance analysis;
Journal_Title :
Signal Processing Letters, IEEE
