Apply Of Turbo Code In LTE System And FPGA Implement

Turbo codes made full use of the randomness decoding conditions in the Shannon channel coding theory, and the decoding performance is almost close to the Shannon theoretical limit. Its amazing excellent decoding performance attracted numerous domestic and foreign scholars to in-depth study, while the turbo code has been widely applied in the field of communication. And in the third generation mobile communication systerm,Turbo code is candidate for channel coding in the specific technical standards.More inportantly,the CCSDS organization has looked the turbo code as one of the the criteria for deep space communications and satellite communication.quasi-turbo codes "4G"LTE systerm is one of the channel coding standards.This paper analyzes the decoding performance of turbo code under the LTE communication system.implementing the turbo encoder and turbo decoder based FPGA.The content in this papper has signficance for research on the pratical application of turbo codes.At the beginning of this article makes a theoretical analysis about critical parts of the turbo Encoder Design:the interleaver, the RSC (component encoder), puncturing, etc.. Then the author deduces calculation methods and formulas of Turbo decoding MAP algorithm,the Log-MAP algorithm and SOVA algorithms. And the author makes an analysis about computational complexity and decoding performance of the three algorithms, under the AWGN channel model and at different decoding algorithm, and then makes simulation based on Matlab. Considering a combination of factors, the author obtains the fitter decoding algorithm in the actual hardware.Analyzing turbo code in the field of communication. the author mainly studys the encoding and decoding structure of turbo code under the LTE system, and makes the Matlab simulation about its performance. Including expansion of different interwined,weving length on thr performance of turbo codes.combined with thr previous decoding algorithm for the simulation results, the conclusion that should be adopted decoding algorithm (the number of log-MAP algorithm), what kind of intertwined way (QPP that we interleavingmode) to the Turbo Code channel coding scheme as in the LTE system. Finally, the author designs and implements turbo codes based on the Log-MAP algorithm and FPGA on the Altera Quartus â…¡ software platform. In the FPGA design and implementation for turbo codes,the author mainly have design and imlement the key module part of the turbo codec.