  Convolutional codes are constructed, designed and analysed using row and/or
block structures of unit algebraic schemes. Infinite series of such codes and
of codes with specific properties are derived. Properties are shown
algebraically and algebraic decoding methods are derived. For a given rate and
given error-correction capability at each component, convolutional codes with
these specifications and with efficient decoding algorithms are constructed.
Explicit prototype examples are given but in general large lengths and large
error capability are achievable. Convolutional codes with efficient decoding
algorithms at or near the maximum free distances attainable for the parameters
are constructible. Unit memory convolutional codes of maximum possible free
distance are designed with practical algebraic decoding algorithms.
  LDPC (low density parity check) convolutional codes with efficient decoding
schemes are constructed and analysed by the methods. Self-dual and
dual-containing convolutional codes may also be designed by the methods;
dual-containing codes enables the construction of quantum codes.
