Difference Between Linear Block Codes and Convolutional Codes

In digital communication, making sure messages are sent without errors is important. Two key methods for achieving this are Linear Block Codes and Convolutional Codes. This article will explain what these codes are, how they work, and their differences in a simple way.

What is Linear Block Codes? 

It is a simple error control coding technique used for error detection and correction.

• Information data is partitioned into blocks of length K pieces for example Information word.
• Every information word is then coded into a block of length n bits called a codeword. Here, n > k
• Also, n = k + r, where 'r ' denotes the parity bits or check bits added to every information word.
• Vector documentation is utilized for the Data word and Codeword: message m = (m₁, m₂ m_n ), Codeword c = (c₁, c₂ c_n).
• Consists of Hamming codes, Reed-Solomon codes(RS), Bose–Chaudhuri–Hocquenghem(BCH), and cyclic codes.

Advantages

• They have a clear structure, making it easy to check for errors.
• It is good for systems that handle data in fixed sizes.

Disadvantages

• The equipment needed can be complicated.
• It is not as effective for streaming data.

What is Convolutional Codes?

Convolutional code is one more kind of error-correcting code where the resulting bits are acquired by putting out an ideal logical procedure on the present bitstream alongside thinking about the previous bit.

• In convolutional codes, just the parity bits possibly containing errors are received by the other user or system, which then decodes it to have the most ideal arrangement of bits i.e message bit itself.
• Shift registers are used to store input bits.
• Block of 'n' digit codeword generated in the encoding depends on not only 'k' message digits, but also on the previous m-1 message blocks.
• Consists of Turbo codes and a Trellis diagram.

Advantages

• It is more effective in correcting errors in continuous data streams.
• It is easy to implement in many cases.

Disadvantages

• They can be less organized than block codes, making error checking more complex.
• It is less effective for data that can be easily divided into blocks.

Difference Between Linear Block Codes and Convolutional Codes

Conclusion

Linear block codes and convolutional codes are both effective methods for error correction in digital communication. Linear block codes work well with fixed-size data blocks, while convolutional codes excel in processing continuous data streams. Understanding their differences helps in choosing the right method based on the needs of the communication system.