Research Of Turbo-code Decoder In 3G System And The Implementation Based On DSP

The noises in the radio channel will corrupt the signal in many kinds of communication systems. The corresponding errors will appear at the receiver. So error-correcting coding technology is an important part in an efficient communication and an interesting field studied by scholars. Turbo codes is a new class of error-correcting codes that can approach the Shannon bound, it is considered as one of the most exciting and potentially important developments in recent years, its invention has changed the minimum Hamming distance of the code to the goal of reducing the number of code words with low Hamming weights. For its excellent decoding performance, it has been adopted as the error-correcting coding scheme is 3rd mobile communication system. Based on reading and studying lots of related documents, this paper analyses the coding steps in detail, explain two kings of iterative decoding algorithm in popular. On these bases, by consulting the applying format of Turbo code in 3GPP, a improved coding scheme is brought forward. Interleave block length, iteration, number of bits these three key parameters are simulated and studied. The simulations manifest the improved coding scheme available. Designing a simplified coding and decoding scheme, used with TI's DSP chip, hardware application is fulfilled. In this paper, the hardware of Turbo decoder is based on the characteristics of the TMS320VC5402 chip.The program is written by standard C in SOVA algorithm on Turbo decoding, and it is compiled and debugged. By debugging the software and the hardware, the influence of main parameters to coding and decoding system is proved, and some useful conclusions are found.