Encoding Schemes for Memory Efficient Quasi Cyclic Low Density Parity Check Codes

Low Density Parity Check (LDPC) codes have attracted current researchers due to their excellent performance and capability of parallel decoding. One major criticism concerning LDPC codes has been their apparent high encoding complexity and memory inefficient nature due to large parity check matrix. This led the researchers to move into a memory efficient LDPC called Quasi-Cyclic (QC)-LDPC which shows the similar performance as LDPC does. This review gives a theoretical and analytical survey on different encoding schemes for QC-LDPC codes. The encoding schemes are categorized in three broad categories. These schemes are then analyzed under those three broad fields. Also different encoding schemes are compared. Key-Words: LDPC, QC-LDPC, efficient encoding, Richardson, Low complexity