Patent ID: 7038732
Filing Date: 2006-05-02
Classification: H04L,H04N

Abstract:
1. A data signal receiver for an electromagnetic wave signal including a pilot carrier and vestigial sideband modulation of a suppressed carrier of the same frequency and phase as said pilot carrier, said vestigial sideband modulation being in accordance with a baseband signal having a uniform symbol rate substantially 684 times the horizontal scan line rate of an NTSC television signal that is apt to accompany said electromagnetic wave signal as a co-channel interfering signal, said baseband signal composed of consecutive data segments each consisting of a prescribed integral number of symbol epochs, said consecutive data segments being divided into contiguous data frames each consisting of a prescribed integral number M of contiguous ones of said data segments, each said data frame characterized by beginning with a data frame header including a plurality N in number of contiguous ones of said data segments and concluding with a plurality (M-N) in number of said data segments including consecutive multi-level symbols used for transmitting data, said data segments used for special purposes in each said data frame including a first ghost-cancellation reference signal and a second ghost-cancellation reference signal at a prescribed time interval thereafter, which said first and second ghost-cancellation reference signal exhibit respective variations that are complementary to each other, said data signal receiver comprising: circuitry for selecting said electromagnetic wave signal, converting the frequencies of said electromagnetic wave signal after its selection, and amplifying said electromagnetic wave signal after its selection and conversion in frequency; circuitry for synchrodyning said electromagnetic wave signal to baseband after its selection, conversion in frequency and amplification and supplying digitized samples of a baseband signal resulting from synchrodyning said electromagnetic wave signal to baseband; an adaptive equalizer for receiving said samples of a baseband signal resulting from synchrodyning said electromagnetic wave signal to baseband, and supplying an equalizer response to those received samples as weighted by kernel weights that are electrically adjustable; circuitry for regenerating transmitted data from said equalizer response; a comb filter for differentially delaying said equalizer response, so said first ghost-cancellation reference signal in the more delayed equalizer response occurs simultaneously with said second ghost-cancellation reference signal in the less delayed equalizer response, and subtractively combining said more delayed equalizer response and said less delayed equalizer response to generate a comb filter response; and a computer responsive to selected portions of said comb filter response including the result of subtractively combining said first and second ghost-cancellation reference signals, for performing initial electrical adjustments of the kernel weights of said adaptive equalizer whenever said data signal receiver is initially operated after a time of in operation or whenever said electromagnetic wave signal is initially selected.