A new GCR waveform for deghosting TV signals

Ghost canceling reference (GCR) signals have been introduced for the purpose of identifying TV channels for removing ghosts when they appear. A GCR signal should have the following features: the capability of exciting the maximum number of channel modes, simplicity of generation and detection with the minimum hardware, and fast adaptation to channel variations. A new GCR sequence is proposed in this paper. It is based on a bipolar binary (+1 or -1) waveform with a certain sequence. This binary GCR enables the receiver to determine the channel impulse response in a simple non-recursive way, hence speeding up the cancellation of ghosts. The technique does not require multiplication or division (only addition and subtraction are required), which accelerates the speed of ghost canceling, lowering its cost, and simplifying its implementation. The identification of the ghost channel using this GCR can be used along with a suitable algorithm to find the optimum tap coefficients of the equalizer which will remove ghost images. In comparison with existing GCR signals, the proposed approach is seen to be more efficient. Simulation results are included