The subject of this Final Project is the development of a Turbo encoder. It is a very effective encoder which was introduced at first in the early 1990s. Since then a lot of methods were born for the implementation of this kind of encoder. Several of these methods comply with special criteria to be used in the defined applications.
The Turbo encoder is a forward error correction encoder, which is the combination of two convolutional encoders. These convolutional encoders have a special feedback line, which causes that the Turbo code closely approach the Shannon limit.
As this task was a part of an industrial project, which aim was to implement a space grade device, it was very important that the encoder should be exact and effective. That is why efficient devices were needed. I developed the Turbo encoder in VHDL language for FPGA environment with the use of the ISE development system.
In this document the requirements of the industrial project are detailed, especially the specifications defined for Turbo encoder. The tools used for the solution are introduced, such as Xilinx’s chosen FPGA and ISE development system. Besides, VHDL language is also reviewed shortly. The types of the forward error correction codes and the characterization of some code types are described briefly. Later on, the implementation of the conceptions and the solving of the emerging problems are detailed and finally the testing procedure and the simulation verification are presented. So the encoder was developed and tested.
Summing up my work it can be declared that the implementation of a Turbo encoder is a very complex task, especially owing to the space standard regulations. But, because of its really high efficiency, its development is a great benefit step for companies which develop high frequency transceivers. Also in certain cases it is highly recommended to use Turbo encoder.