| Author | Amphol Tangtongpairoth |
| Call Number | AIT RSPR no. TC-99-06 |
| Subject(s) | Artificial satellites in telecommunication
|
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master
of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | In 21st century, mobile satellite communication is proposed to be developed into the personal satellite communication. To use smaller handheld terminal, which can directly access the satellite, a lower satellite orbit is needed. In this research study, Trellis Code Modulation (TCM) has been proposed the above scenario. TCM is a combined coding and modulation scheme for improving the reliability of a digital transmission system without increasing the transmitted power or the required bandwidth, and hence is suitable for mobile satellite channel. This research presents the error performance of TCM schemes when applied to AWGN, flat fading Rician and shadowed Rician channel. The Ungerboeck encoders and Wilson and Leung encoders are considered with symbol block interleaver/deinterleaver, which distribute the burst errors to random error. The natural bit mapping and Gray bit mapping are introduced to consider the effect of the error performance. The Doppler effect resulted from the movement of nongeostationary satellite, such as Iridium system, and the movement of mobile satellite terminal is considered. The simulation model consists of TCM encoder, interleaver/deinterleaver and TCM decoder, which use the sofe decission Viterbi decoder with ideal channel state information. The results are given for A WGN, flat fading Rician and shadowed Rician channel. The simulation results show that Ungerboeck encoder gives the best performance in AWGN and the Wilson and Leung encoder is the best for both of fading channels. The performance of TCM encoder is degraded by the factor of dominant path. The performance of Rician channel is normally better than shadowed Rician channel where the effect of shadowing of the dominant path of shadowed Rician channel degrades the performance. Finally, the increasing number states of TCM encoder give an improved performance. |
| Year | 1999 |
| Type | Research Study Project Report (RSPR) |
| School | School of Advanced Technologies (SAT) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Rajatheva, R.M.A.P. |
| Examination Committee(s) | Ahmed, Kazi Mohiuddin;Makelainen, Kimmo; |
| Scholarship Donor(s) | Telephone Organization of Thailand (TOT); |
| Degree | Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 1999 |