Ghost canceller with variable delay selector

A television receiver comprising:

• a display device for displaying video images, and
• a channel equalizer for receiving a video signal with one or more ghosts from a multi-path channel and for outputting said video signal with said one or more ghosts cancelled for display on said display device, said channel equalizer comprising:
• an electronic processor for computing an array of tap coefficients for said one or more ghosts of said received video signal, and
• a filter for receiving said tap coefficients, for cancelling each of said one or more ghosts by filtering said received video signal with a corresponding array of tap coefficients, said filter comprising:
• I variable delay elements sequentially connected in tandem, where I is an integer .gtoreq.1, a first of said variable delay elements capable of receiving said received video signal, each variable delay element capable of outputting said video signal delayed by a sum of delay periods of that variable delay element which are adjusted therein and delay periods adjusted in each preceding variable delay element,
• J multiplexers, where J is an integer .gtoreq.1, each of said multiplexers capable of selecting the delayed video signal outputted from any one of said I variable delay elements,
• J transversal filter elements, each capable of receiving the delayed video signal selected by a corresponding one of said J multiplexers, and also receiving one of said arrays of tap coefficients, for filtering said selected delayed video signal with said array of tap coefficients, and
• an adder circuit, for adding together the filtered video signal outputted from each of said transversal filter elements.

A process for cancelling a ghost from a received video signal comprising:

• inputting a video signal to I variable delay elements sequentially connected in tandem, where I is an integer .gtoreq.1,
• adjusting a delay of a first i of said variable delay elements, where i is an integer 1.ltoreq.i.ltoreq.I, such that a video signal outputted by the i.sup.th variable delay element is delayed an amount approximately equal to the period separating said ghost from a main signal within said received video signal,
• selecting as the output of a multiplexer, said delayed video signal outputted by said i.sup.th variable delay element, and
• filtering said delayed video signal with tap coefficients, suitable determined for cancelling said ghost in a transversal filter element connected said multiplexer.

A process for overlapping P arrays of lower precision tap coefficients comprising:

• adjusting a delay period of at least one daisy chained variable delay element to be approximately equal to the interval separating a ghost from a main video signal to be recovered,
• selecting as the output of P multiplexers, the delayed video signal outputted by said at least one daisy chained variable delay element, where P is an integer >1,
• separately and simultaneously filtering each video signal outputted by said P multiplexers in one of P transversal filter elements connected to each of said P multiplexers, respectively, with a corresponding one of P lower precision arrays of tap coefficients, and
• adding together the video signals outputted by said P transversal filter elements,
• wherein the sum of said P lower precision arrays equals a predetermined higher precision array of tap coefficients suitably determined for cancelling said ghost.