Low state complexity block codes via convolutional codes

A new class of block codes with low state complexity of their conventional trellis representations called double zero-tail terminated convolutional codes (DZT codes) is introduced. It is shown that there exist DZT-codes meeting the Varshamov-Gilbert bound on the minimum distance and having asymptotically optimal state complexity. Two ways of constructing DZT-codes are considered. Examples of DZT-codes meeting a lower bound on the state complexity are given.