State Diagram:Since the encoder is a linear sequential circuit,its behavior can be described by a state diagram.The encoder state at time is represented by the message ◆ The encoder of the (2,1.2)convolutional code given in the example has 4 possible states,and its state diagram is shown in the figure below. 000 00 011 output 0 0/01 0/10 11 1/01 label=input/output Trellis diagram:The state diag gram can be expanded in time to display the state transition of a convolutional encoder in time.This expansion in time results in a trellis diagram. state 110 010 100 001 010y 0 The encoding of a message sequence u is equivalent to tracing a path through the trellis. The trellis structure is very useful in decoding a convolutional code. 66 „ State Diagram: Since the encoder is a linear sequential circuit, its behavior can be described by a state diagram. The encoder state at time l is represented by the message bits stored in the memory units. „ The encoder of the (2, 1, 2) convolutional code given in the example has 4 possible states, and its state diagram is shown in the figure below . 00 01 10 11 0/00 1/11 1/00 0/01 1/01 0/10 1/10 0/11 input output label = input/output „ Trellis diagram: The state diagram can be expanded in time to display the state transition of a convolutional encoder in time. This expansion in time results in a trellis diagram. „ The encoding of a message sequence u is equivalent to tracing a path through the trellis. „ The trellis structure is very useful in decoding a convolutional code