Properties of LDPC Codes

1
Properties of LDPC Codes

• One kind of Block Codes
• H is sparse
• Very few 1s in each row and column
• Variety of H (wr ,wc ) LDPC codes
• If each row is of fixed weight wr and column is
  of fixed weight wc, then it is regular.
• If not, thats irregular.
• Suppose a LDPC code is a (n,k) block code
• H is a (n-k) x n matrix
• (n-k) .wr n.wc
• Code rate k/n 1-wc/wr

2
Simulation Result in Fading channels
3
Our Decoder Motivation

• CAM based
• Broadcast access
• SIMD (Single Instruction Multiple Data Stream)

4
Conclusion and Future work

• Study of LDPC and decoding algorithms.
• In choosing of LDPC architecture, memory-based
  organization has more flexibility than parallel
  hardwired one in recently years.
• Various industry standards adopting LDPC as a
  channel code are surveyed and we propose an
  efficient generic LDPC decoder to implement.
• IC can be implemented with our architecture by
  specializing dedicated vendor library to minimize
  area.