On doubly-cyclic convolutional codes
  Cyclicity of a convolutional code (CC) is relying on a nontrivial automorphism of the algebra F[x]/(x^n-1), where F is a finite field. If this automorphism itself has certain specific cyclicity properties one is lead to the class of doubly-cyclic CC's. Within this large class Reed-Solomon and BCH convolutional codes can be defined. After constructing doubly-cyclic CC's, basic properties are derived on the basis of which distance properties of Reed-Solomon convolutional codes are investigated.This shows that some of them are optimal or near optimal with respect to distance and performance. 
Heide Gluesing-Luerssen, Wiland Schmale