ADAPTIVE BLIND EQUALIZATION COUPLED WITH CARRIER RECOVERY FOR HDTV MODEM

We introduce an adaptive blind equalization coupled with carrier recovery for HDTV modem. The adaptive equalization, which is called a modified ''stop-and-go'' algorithm(MSGA), is based on the combination of the constant modulus algorithm (CMA)[1] and a ''stop-and-go'' algorithm (SGA)[2]. The CMA is first used to initialize the coefficients; once initialized, the CMA is switched to the MSGA for completing 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 nonimpulsive noise, multipaths and carrier errors such as frequency offset, phase offset and phase jitter.