Some optimal partial-unit-memory codes (Corresp.)
Gregory Lauer · IEEE Transactions on Information Theory · 1979
A new class of time-invariant binary convolutional codes is defined, called partial-unit-memory codes. These codes are optimal in the sense of having maximum free distance for given values ofR, k(the number of encoder inputs), and\mu(the number of encoder memory cells). New optimal codes are given for ratesR=l/4, 1/3, 1/2, \and 2/3with\mu \leq 4 \and k \leq \mu + \3, whenever such a code is better than previously known An infinite class of optimal partial-unit-memory codes is also constructed based on equidistant block codes.