Patent ID: 6788349
Filing Date: 2004-09-07
Classification: H04L,H04N

Abstract:
A method for transmitting digital data within an analog TV signal comprising the steps of:receiving the digital data from a data source; multilevel encoding the digital data and providing a plurality of data symbols in parallel in dependence thereupon; and, modulating in frequency domain each of the plurality of data symbols onto a carrier of a plurality of carriers such that each carrier carries a different data symbol for providing a digital data signal in dependence thereupon, wherein some carriers of the plurality of carriers are turned off to shape the spectrum of the digital data signal such that the spectrum of the digital data signal comprises notches at locations coinciding with locations of spectral components of the analog TV signal, and wherein the width of the notches is determined such that degradation of the analog TV signal due to the transmission of the digital data within the analog TV signal is substantially reduced.