Forward error correction of data transmitted via television signals

Abstract

An encoding technique for data that enables the data to be reliably transmitted via television signals, even when impulse noise may be present, uses a two-fold approach for forward error correction. As a first step, the data is assembled into blocks of suitable length and each block is encoded with an error correcting code to enable individual bit errors to be identified and corrected at the receiving end. In addition, the blocks of data are interleaved over several different lines of information. Each line of information is transmitted during the vertical blanking interval in a respective field of a video signal. At the receiving end, the individual lines of data are reassembled into the blocks of information. If impulse noise or other disruptions cause one of the lines to be lost, the result at the receiving end would only be the loss of one bit of data in each block. The error correcting code with which each block is encoded enables this individual bit error to be identified and corrected.