Its a convolutional encoder with code rate of 1/2 and constraint length of 3. i/p=1 bit o/p=2 bits with 4 memory elements

matlab code for convolutional encoder

实现卷积编码和相应的维特比译码（卷积码编码器为（2，1，3），维特比译码针对第1、3位模二加和第1、2位模二加）-Convolutional coding and the corresponding realization of Viterbi decoding (convolutional code encoder for the (2,1,3), Viterbi decoder bit mode for the first 1,3 and 1,2 position two plus two