A design procedure is presented for synthesizing threshold decodable rate

and

self-orthogonal block codes obtained from truncating convolutional codes by generalized tail-biting (GTB). When GTB is applied to an equal error-protection threshold decodable convolutional code, the result is a class of unequal error-protection threshold decodable block codes. These codes are related to unequal error-protection codes previously described by Mandelbaum [1]. Furthermore, the codes of Mandelbaum are generalized.