Channel Coding(Proakis: chapter 12.4, 12.5, 12.6, 13.1, 13.2)
Dong In KimCollege of Info/Comm Engineering
Sungkyunkwan University
Digital Communication System
cont …
DONG IN KIM
We can achieve 1 bit/sec/Hz spectral efficiency with SNR=0dB in channel capacity while in BPSK with SNR=9.6dB at BER=10**-5.
Types of Channel Coding
DONG IN KIM
Memoryless channel coding
DONG IN KIM
Channel coding with memory
Example : (7,4) Hamming Code
DONG IN KIM
DONG IN KIM
DONG IN KIM
DONG IN KIM
DONG IN KIM
Properties of Block Codes
DONG IN KIM
DONG IN KIM
DONG IN KIM
DONG IN KIM
DONG IN KIM
cont …
DONG IN KIM
This cyclic property is useful for simplifying the decoding procedure via a shift register.
Decoding of Block Codes
DONG IN KIM
One-bit error is more likely whereas two-bit error is less likely!
Error Correction Capability
Probability of Codeword Error
Example : (7,4) Hamming Code
Per-bit SNR for Coded System
DONG IN KIM
DONG IN KIM
DONG IN KIM