  The original local, discrete example of Linear Unitary Cellular Automata
(LUCA) is analyzed in terms of a new representation previously introduced in
[1] for classical CA. Several important underlying symmetries are reviewed and
their tight relationship with both signal and coding theory as well as with
combinatorics is underlined. A class of analog implementations in the form of
Linear Transmission Line Networks (LTLN) is described as possible emulators of
this type of dynamics.
