A hardware efficient phase/gain tracking loop for the Grand Alliance VSB HDTV receiver

The Grand Alliance VSB HDTV system is a terrestrial HDTV broadcasting standard for the USA. We propose a hardware efficient algorithm for the phase/gain tracking loop block which tracks out the residual phase noise and slowly varying gain error at the output of the channel equalizer. In the proposed algorithm, the phase error is calculated using a modified decision directed (DD) method where a stop-and-go type flag is used to allow the update of the de-rotation phase only when the sign of the DD phase error is considered to be reliable. Computer simulations are performed and the satisfactory performance of the phase/gain tracking loop is verified.