The Design Of Turbo Decoder Based On Tta Analysis

Turbo code has attracted interest from academia and industry because of its excellent performance and becoming focus of study since it arose. As research continues, Turbo code has been widely used in wireless communications, satellite communications and so on. It It’s already been the key component of those system. However, with the development of technology, the requirement for the performance, flexibility and development period of Turbo decoder is increasing. TTA is a new kind of ASIP design architecture. ASIP based on TTA has its own advantages, such as good performance, flexibility and extendibility. So TTA is suitable for Turbo decoder implementation. This thesis focusing on the design of Turbo decoder based on TTA.Firstly, the thesis introduces the feature of TTA, the component and usage of TCE and the development process of TTA processors. Then, from the point of view of the theory of Turbo, we introduce something of the structure of Turbo coding. Three kinds of MAP series decoding algorithm and their difference have also been discussed in this thesis. And the parallel decoding algorithm has been raised. To research the relationship of parallelism degree, iterations and performance, some simulation has been done using C language. Of course, the float-point to fixed-point has also been discussed in the thesis. The design of two most important module of Turbo decoder target on TTA, SISO and interleaver, has been introduced in details, including computation procedure and circuit design. Meanwhile, the thesis presented two structures of Turbo decoder based on TTA according to the function unit which has been designed, the decoder with big granularity based on SISO and the decoder with litter granularity based on smaller calculation modules. Finally, a general conclusion about the granularity of function unit is given through the test and analysises. The thesis explored the design of Turbo decoder based on TTA and verified the possibility to implement the parallel decoding algorithm on TTA. In addition, the function circuit of Log_MAP algorithm has a certain commonality. Finally, the general conclusion about the granularity of function unit has a certain extend reference meaning.