message register To channe III.Convolution Coding During each unit of time,the input to convolutional is also a k-bit messa ge block and the corresponding is also ann-bit coded withk<n.(为避免混淆，可改为用ka,m表示) Each coded n-bit output block depends not only on the corresponding k-bit input message block at the same time unit but also on the m previous message blocks. Encoder (memory) Input data stream shift register data fram 运算逻辑 有记忆 encoder odeword fram The code rate is defined as R=k/n. The parameter m is called the memory order of the code4 ⊕ ⊕ ⊕ u 0 c 1 c 2 c III. Convolution Coding „ During each unit of time, the input to convolutional is also a k-bit message block and the corresponding is also an n-bit coded with k<n. (为避免混淆，可改为用 k0, n0 表示) „ Each coded n-bit output block depends not only on the corresponding k-bit input message block at the same time unit but also on the m previous message blocks. # # Encoder (memory) u (1) u (2) u ( )k u ( )n c (2) c (1) c c    Input data stream shift register 运算逻辑 n nn n encoder codeword frame data frame 有记忆 N „ The code rate is defined as R = k n/ . The parameter m is called the memory order of the code