Some Results on the Distance Properties of Convolutional Codes

Rate 1/2 binary convolutional codes are analyzed and a lower bound on free distance in terms of the minimum distances of two associated cyclic codes is derived. Next, the complexity of computing the free distance is discussed and a counterexample to a conjecture on the relationship of row distance to free distance for systematic codes is presented. Finally, an improved Gilbert bound for definite decoding is derived. SECTION