Adaptive blind equalization coupled with carrier recovery for HDTV modem

Abstract

An adaptive blind equalization coupled with carrier recovery for the high-definition television (HDTV) modem is introduced. The adaptive equalization, which is called a modified 'stop-and-go' algorithm (MSGA), is based on the combination of the constant modulus algorithm (CMA) and a 'stop-and-go' algorithm (SGA). The CMA is first used to initialize the coefficients; once initialized, the CMA is switched to the MSGA to complete the equalizer convergence. In order to obtain faster convergence, the Sato-like errors used in the SGA are replaced by errors used for updating coefficients in the CMA. The carrier recovery for coupling with the adaptive equalization uses the decision-directed technique. The calculation of absolute sum of error gives a simple and reliable way of switching from CMA to MSGA for the adaptive equalizer's coefficient updating procedure. Test results confirm that the proposed scheme is robust against impulsive and/or nonimpulse noise, multipaths, and carrier errors such as frequency offset, phase offset, and phase jitter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>