Error Control Coding - Digital Communication: Principles and System Modelling - page 195

00

Fig. 9.8 Code tree for (2,1,2)
convolutional encoder

00

a

00 b

11
10

a

c

11

01 d

00

a

11

10

a

b

11 00

01

b

c

m=0 01

10

d

Reset

a

00

a

11

m=1

11
10

b

10

c

c

00

01

d

11

b

11

a

01

01 00

01

b

d

c

10

10 d

Current State Output Next State

00

00=a 00=a

11 11

01=b 01=b

00

10
01

10=c 10=c

01

Fig. 9.9 Trellis diagram for
(2,1,2) convolutional encoder

11=d 11=d

10