Research

Ph.D. Thesis (in progress)

Turbo CPM based on structural optimization of a binary or non binary LDPC code with 2 or 4 ary modulation.

  • Abstract: The use of continuous phase modulation (CPM) is interesting when the channel represents a strong nonlinearity in the case of limited spectral support. We face such schem for instance in multimedia satellite-based communications: for the uplink, when the satellite holds an amplificator per carrier and for downlinks when the terminal equipment works in saturation region. Numerous studies has been done on this issue but the proposed solutions deal with iterative CPM demodulation/decoding concatenated with convolutional or block error correction codes. The use of LDPC codes has not yet been introduced. Particularly, no works, to our knowledge, have been done on optimization of binary and non binary LDPC codes adapted for the use described here. In this study, we propose to perform an asymptotical analysis and design a turbo-CPM system based on optimization of binary and non binary LDPC codes (use of a ring structure as suggested in an IEEE paper of Trans. on IT). A particular interest will be given to short codes (downlinks) and to adaptive aspect of the schema. The study could be for instance inspired by works on finite non binary LDPC codes. Also, an analysis on the corresponding receiver (handling turbo synchronisation with various techniques such as decision attempt) will be done.
  • Academic advisors: Charly Poulliat, Marie-Laure Boucheret,
  • Industrial advisors: Benjamin Gadat from Thales Alenia Space (TAS), Guy Lesthievent from the French Space Agency (CNES)