Some new runlength-limited convolutional codes

This article presents a method to find convolutional codes with good translation properties by modifying the generator matrix of existing codes and using a bit modifier. Applying the method causes no loss in the error correcting performance and only slight modifications to the architecture of existing encoders and decoders. The new codes´ maximal runs of both zeros and ones are constrained. It is shown that some of the new line codes are DC-free.