Publication details

Home Publications Publication details

Application of LDPC Codes on Networks
Agrawal A, Ambroze MA
Advances in Communications, Computing, Networks and Security Volume 8, ISBN: 978-1-84102-293-2, pp149-157, 2011
Can be ordered on-line.
Download links:  Download PDF

The current communication systems face many problems these days during the transmission of
data, which are network efficiency and congestion. This relates to quality of service of the data
transmitted- i.e. data rate, delay, delay variation and packet loss which are provided to the
customer. Congestion causes packets to be lost, due to which retransmission of packets takes
place and this in turn can increase congestion in the network. From error correction point of
view, retransmissions represent an inefficient type of code called as the repetition code, which
is known to have high overhead.


This paper investigated the way to reduce the need for retransmission of the lost packet by
using efficient error correction codes, such as Low-density parity check (LDPC) codes. They
were invented by Gallager in 1963 and had been forgotten until Mackay rediscovered it. They
are able to reconstruct the number of lost packets at the receiver end.


This project discusses the iterative decoding and Gaussian elimination decoding methods for
their application to decode the received code word with erasures in the binary erasure channel.
The information bits will be encoded which is combination of information bits and the
redundant bits called as code word which is subjected to noise when transmitted through the
binary erasure channel. The error occurs in the form of erasure of the bits from the code word,
which is then decoded with the help of the two decoding methods.

Agrawal A, Ambroze MA