MODELING OF TURBO-PRODUCT-CODES DECODING PROCESS USING MODELSIM ENVIRONMENT

Abstract

In the article the results of modeling of developed Turbo-Product-codes (TP-codes) decoder in ModelSim environment have been presented. The method of modeling and implementation of test-benches for this type of devices are described. The decoder under modeling has a feature of changing the code to process the message immediately during the work state. Correspondingly, it is able to work not just with one code but also with a set of codes. Configuration change can be performed after the end of decoding current encoded message. It provides a great advantage as such decoder can utilize different codes according to external conditions concerned with signal transmission. It allows to im-prove the efficiency of information transmission system and can eventually make a notable gain for many decoder’s working parameters (correction ability, throughput, cost of development, etc.). All the stages of decoder work are thoroughly considered and presented with wave diagrams for every single stage. ModelSim environment ensures the possibility of demonstration of each separate block, as well as the whole system and intercommunication among blocks. It makes possible to assess the correct-ness of decoding stages and general decoding results. Testbench and decoder itself have been imple-mented in VHDL description language. During the work of testbench file operations are used inten-sively (input, output, and intermediate data). The result of testbench work is compared with the result of software model to prove the correctness of implementation. The comparison is performed byte-to-byte and demonstrates the same results both for ModelSim and software model. In future, implemented means can be extended for using in decoders modeling for TP-codes with different structure and for other types of error-correcting codes.