Convolutional Codes Using Nonlinear Generators for Rate One-third and Memory Order Four

Performance of a convolutional code depends on the decoding algorithm and that code´s distance properties. Performance bounds suggest constructing codes with the largest possible free distance. Published tables provide the feed forward encoding equations that are linear generator polynomials over a binary Galois field. This paper presents results for rate one-third, memory order four, convolutional codes with at least one feed forward encoding equation that is nonlinear over a binary Galois field.