On interleaved, differentially encoded convolutional codes

On interleaved, differentially encoded convolutional codes

We study a serially interleaved concatenated code construction, where the outer code is a standard convolutional code, and the inner code is a recursive convolutional code of rate 1. Focus is put on the ubiquitous inner differential encoder (used in particular to resolve phase ambiguities), double differential encoder (used to resolve both phase and frequency ambiguities), and another rate 1 re...

On Woven Convolutional Codes

On cyclic convolutional codes

We investigate the notion of cyclicity for convolutional codes as it has been introduced in the papers [15, 18]. Codes of this type are described as submodules of F[z]n with some additional generalized cyclic structure but also as specific left ideals in a skew polynomial ring. Extending a result of [15], we show in a purely algebraic setting that these ideals are always principal. This leads t...

New convolutional codes from old convolutional codes

In this paper, starting with a family of convolutional codes, we construct a new convolutional code and we introduce also necessary and sufficient conditions in order that the new convolutional code is MDS.

On differentially encoded M-sequences

In this letter, we show that a differentially encoded maximal-length shift register sequence (or M-sequence) is also an M-sequence or the logical complement of an M-sequence. The differentially encoded sequence is a cyclically shifted version of the original M-sequence or its complement.