Patent ID: 7773001

Claim:
A method of channel encoding binary data consisting of a sequence of data blocks, comprising steps of separating from the data blocks head parts having individual head part lengths which enable that dk-encoding the head parts does not depend on a subsequent remainder of the respective data block; separating the remainder of each of the data blocks into a body part and a tail part having individual lengths which enable that dk-encoding the body parts does not depend on the subsequent tail parts; combining the tail part of a previous data block with an inverting control bit pattern and the head part of a current data block into a polarity inverting control block; combining the tail part of the previous data block with a preserving control bit pattern and the head part of the current data block into a polarity preserving control block; dk-encoding the polarity inverting control block and the polarity preserving control block; evaluating one Running Digital Sum difference each, for the dk-encoded polarity inverting control block and for the dk-encoded polarity preserving control block; and deriving therefrom Running Digital Sums for the polarity inverting case and for the polarity preserving case; selecting, as a selected control block, one of the dk-encoded polarity inverting control block and the dk-encoded polarity preserving control block, depending on which of the Running Digital Sums has smaller magnitude; time-multiplexing the selected control block together with a dk-encoded body part, and NRZI modulating the result into the channel encoded binary data.