Generation of trellis-coded modulation schemes

A method for generating a Trellis-Coded Modulation (TCM) scheme for transmitting symbols over a Partial-Response (PR) channel, the method including holding a base TCM scheme including a plurality of states and transitions among the states. Sequences of symbols are produced, and second sequences of symbols are calculated, each second sequence emulating a response of the PR channel to a respective sequence of symbols traversing the PR channel. The TCM scheme is initialized by assigning the sequences to the transitions of the base TCM scheme. One or more transitions are removed so that second sequences corresponding to transitions that were not removed are separated by at least a first distance. One or more additional transitions are further removed from the TCM scheme, so that second sequences corresponding to parallel transitions from a current state to a next state are separated by at least a second distance larger than the first distance.