Method and device of superimposing an additional information signal on a video signal and detecting said additional information from said video signal

A method of superimposing a spectrally spread additional information signal on a video signal, and detecting said additional information from said video signal on which said additional information is superimposed, wherein:

• a first spectral spreading code is generated in predetermined intervals synchronized with a sync signal contained in the video signal,
• inverting and non-inverting spectral spreading codes are generated by inverting the polarity of said first spectral spreading code in said predetermined interval units,
• an additional information signal is spectrally spread by said inverted and non-inverted spectral spreading codes to generate a spectrally spread additional information signal,
• the spectrally spread additional information signal is superimposed on said video signal to generate a video signal with additional information,
• a second spectral spreading code which is the same as the first spectral spreading code is generated in synchronism with the sync signal contained in said video signal with additional information,
• values of said video signal with additional information corresponding to chips of said second spectral spreading code are added or subtracted according to the values of said chips of said second spectrally spread signal and the polarity of said predetermined intervals to calculate a cumulative value, and
• said additional information in said video signal with additional information is detected by determining whether the cumulative value exceeded either a positive or negative threshold value.

A device for superimposing an additional information signal on a video signal, and detecting said additional information from said video signal on which said additional information is superimposed, wherein:

• a first spectral spreading code is generated in predetermined intervals synchronized with a sync signal contained in the video signal,
• inverting and non-inverting spectral spreading codes are generated by inverting the polarity of said first spectral spreading code in said predetermined interval units,
• the additional information signal is spectrally spread by said inverting and non-inverting spectral spreading codes to generate a spectrally spread additional information signal,
• the spectrally spread additional information signal is superimposed on said video signal to generate a video signal with additional information,
• a second spectral spreading code which is the same as the first spectral spreading code is generated in synchronism with the sync signal contained in said video signal with additional information,
• values of said video signal with additional information corresponding to chips of said second spectral spreading code are added or subtracted according to the values of said chips of said second spectrally spread signal and the polarity of said predetermined intervals to calculate a cumulative value,
• said additional information in said video signal with additional information is detected by determining whether the cumulative value exceeded either a positive or negative threshold value.

A device for superimposing a spectrally spread additional information signal on a video signal, and detecting said additional information from said video signal on which said additional information is superimposed, wherein:

• a spectral spreading code is generated in predetermined intervals synchronized with a sync signal contained in the video signal,
• inverting and non-inverting spectral spreading codes are generated by inverting the polarity of said spectral spreading code in said predetermined interval units,
• an additional information signal is spectrally spread by said inverted and non-inverted spectral spreading codes to generate a spectrally spread additional information signal,
• the spectrally spread additional information signal is superimposed on said video signal to generate a video signal with additional information,
• a spectral spreading code which is the same as the aforesaid spectral spreading code is generated in synchronism with the sync signal contained in said video signal with additional information,
• values of said video signal with additional information corresponding to chips of said spectral spreading code are added or subtracted according to the values of said chips of said spectrally spread signal and the polarity of said predetermined intervals to calculate a cumulative value,
• said additional information in said video signal with additional information is detected by determining whether the cumulative value exceeded either a positive or negative threshold value.