Low density parity check codes for turbo equalization | |
| Author | Hoang Minh Duc |
| Call Number | AIT Thesis no.TC-03-15 |
| Subject(s) | Equalizers (Electronics) Decoders (Electronics) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, |
| Publisher | Asian Institute of Technology |
| Series Statement | School of Engineering and Technology |
| Abstract | Density evolution is an algorithm for computing the capacity of LDPC codes under message passing decoding. It has been used to design powerful LDPC codes for many channels so far. However this algorithm faces the infinite-dimensional problem of iteratively calculating message densities of the message passing decoding algorithm, leading to the result that the computational complexity is extremely high, especially when applied to the ISI channel with long memory. In this thesis, following the idea of simplifying the density evolution algorithm by assuming that the messages passing within the decoder are symmetric Gaussian variables in the A WGN channel, we develop an algorithm of designing LDPC codes for the ISI channel. Turbo equalizer is applied at the receiver side of the system. The LDPC codes are designed based on a given channel and a specific Turbo equalizer. First, the EXIT chart of the equalizer is constructed. Then, the optimization process of the LDPC codes is performed similar to that proposed by Chung et al for the A WGN channel. Therefore, the optimization algorithm is rather simple to be performed. Results show that this algorithm works quite well for the partial response channels. Both optimum and sub-optimum Turbo equalizers are applied in the system, their performance in term of .complexity and capacity loss are also discussed. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-03-15 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Ahmed, Kazi M. ; |
| Examination Committee(s) | Erke, Tapio J. ;Teerapat Sanguankotchakorn; |
| Scholarship Donor(s) | Her Majesty the Queen of Thailand; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2003 |