It is shown that any rate l/b systematic convolutional code over GF(p) can be decoded up to its minimum distance with respect to the decoding constraint length by a one-step threshold decoder. It is further shown that this decoding method can be generalized in a natural way to allow “decoding” of a received sequence in its unquantized analog form.
Rudolph, Luther D., "Generalized Threshold Decoding of Convolutional Codes" (1969). Electrical Engineering and Computer Science Technical Reports. 15.