الفهرس | Only 14 pages are availabe for public view |
Abstract Wireless technologies, such as satellite communications are now commercially driven by ever more demanding consumers. Due to the growing need to quickly transmit information wirelessly and accurately, Error-control codes are used in almost the entire range of information communication, storage and processing systems. Rapid advances in electronic and optical devices and systems have enabled the implementation of very powerful codes with close to optimum error- control performance. In addition, new types of code, and new decoding methods, have recently been developed and are starting to be applied. However, error- control coding is complex, novel and unfamiliar, not yet widely understood and appreciated. In this thesis, we discuss the error correcting codes and their types concerning on the turbo coding one. For improving the turbo coding performance we introduce an Adaptive Early Termination Turbo-Decoding model which depends on the decoding threshold and the cross entropy stopping criteria which help the iterative decoder to stop in either high-SNk situation where the decoded bits are highly reliable or in low-SNR situation where the decoder already has no capability to decode (unsolvable decoding). After this we apply turbo coding in the coded OFDM with nonlinear power amplifier system. This turbo coded OFDM is used for improving the performance of the OFDM in satellite channel helping it to solve its problems such as PAPR and nonlinearity which can be explained in our simulation. |