On the Direct Product of Convolutional Codes
The algebraic description of convolutional codes as block codes over the field F(D) of rational functions and the search for new methods to concatenate convolutional codes, gave rise to the idea of applying the direct product, method defined for block codes, to convolutional codes. The result is a concatenated code named product convolutional code. This code has good coding features, such as simple analytical structure, good error correcting capability, suitability for iterative decoding and large free distance with low complexity decoding. Several aspects of these new codes, such as its definition, structural properties, encoding and decoding methods, performance, error exponent over the BSC and a space-time application, have been investigated.