The Implementation Of Turbo Decoder And Encoder On DSP

A great development has been accelerated since1948, after Shannon published hispaper “A mathematical theory of communication”. The most important achievementmust be the Turbo Code. Because of its good performance of closing to Shannon limit,since1993after the Turbo code was raised, the communication area pay great attentionto it, and it became one of the key areas of research in channel coding.After tens of research and development, the theory of Turbo has been completedmostly, and it can now be used in a real system, so this paper mainly describes how toimplement the Turbo decoder by using DSP processor. The thesis includes thefollowing parts:First, the principle of Turbo encode and decode is introduced, including decoder、encoder、decoding algorithms. Then the principle of these two decoding algorithms isderived, and the simulation results of the Matlab programs of these two decodingalgorithm are given.Secondly, the hardware platform of achieving Turbo decoder is described: XXXDSP, including the resources、the instruction set and the memory space of it. And thespecific requirement of evaluating、the data should be given and the steps of evaluatingare described.Thirdly, we discussed the way to run the float-point program on fix-point DSP,and the simulation results of the two fix-point programs are given.Finally we completed Turbo decoder which used SOVA decoder algorithm byusing XXX DSP instruction set. we described in detail how to achieve the parts ofdecoder and the decoding algorithm in assembly instruction set, and run the decodingprogram on the real chip’s verification platform; the results are close to the Matlabsimulation results of the fix-pointed programs.