Introduction: Channel Coding

1
Introduction Channel Coding
Introduction Channel Coding
Principle Add redundancy to minimize error rate
Transmitter
Receiver
Source
Sink
1
1
0
1
1
1
0
1
Channel
2
Different channel types
Binary Symmetric Channel
Additive White Gaussian Noise Channel

MIMO Channel
3
Convolutional Codes
Convolutional Codes
Output 1
00
01
Input
z-1
z-1
10
Output 2
11
(m1m2)

• Coding a bit sequence Choosing one path in
  trellis graph
• Decoding Find the most likely path

• Coding by convolution
• Encoder is a Finite-State-Machine

4
Code Concatenation
Super-Channel
5
Turbo Codes
Turbo Codes

• One Decoder (D) for every Encoder (C)
• Iterative Decoding D1 D2 D1 D2 D1
• Improved Bit-Error Rate Performance

Turbo Decoder
Turbo Encoder
Û
U
C 1
C 2