Non-Electrical Error Correction Coding
September 23, 1997

• So far, we were concerned primarily with efficient binary encoding of messages.
• This is often referred to as source coding.
• We will shift our attention on applying a second stage of coding.
• The binary output of the source coder is coded again.
• However, in this coder efficiency is not the primary objective.
• Instead, bits are added strategically to provide error detection or correction capabilities.
• This form of coding is referred to as (forward) error correction coding (acronym FEC).
• The term channel coding is also used.
• The pupose of the channel coder is to insert bits in such a manner that the decoder can detect the presence of errors or even correct transmission errors.
• The term channel is a generic term for a communication link.
• Transmission errors are unavoidable in communication links.
• Before looking at error correction coding in electrical systems, we consider examples of FEC in every day life.

  

Figure 2.16: Block diagram of communication system