The Research Of Self-adaptive Fault-tolerance For CCSDS Image Compression Algorithm

With the development of deep-space exploration technology, the volume of space remote sensing image is increasing dramatically, which results in the increasingly outstanding contradiction between limited communication channel capacity and quantity of satellite payload transport demand. And the data transmission and storage faces a great challenge. The satellite image compression technology of high efficiency and high fidelity becomes an important technique to alleviate this contradiction. In 2005, The Consultative Committee for Space Data Systems(CCSDS) published new recommended standard CCSDS-IDC for space image data compression, which has low algorithm complexity. It has become an effective solution for space-borne image compression,for its easy high-speed hardware implementation. However,satellite-based electronic system implemented with FPGA circuit is susceptible to the influence of single event upset(SEU), because of the radiation of high-energy particle in deep-space and the high density of modern FPGA component. Consequently, the research of self-adaptive fault-tolertance for satellite-based image compression algorithm has important significance for the enhancement of reliability of satellite-based image compression system.The research is based on CCSDS space-borne image compression algorithm, and aims at improving the compression system’s self-adaptive fault-tolerant ability. The fault-tolertant technology and system architecture of CCSDS satellite image compression algorithm are detailedly studied in the thesis.On the basis of a detailed study of FPGA architecture and operation principle, the paper provides an analysis of the influence of SEU on SRAM-based FPGA. Then, the principle of FPGA reconfiguration, selection of configuration access port and decomposition of configure frame are presented. With the perspective of methodology, the thesis introduces key design technologies and a general framework of a fault-tolerant system used to SEU Mitigation, which includes error detection mechanism, diagnosis and correction strategy. Also a comparison between the exist scheme is presented.CCSDS-IDC is an wavelet based image compression algorithm, which is applicable to a wide range of space-borne image data and can be used to produce both lossy and lossless compression. The compressor consists of two functional parts, a discrete wavelet transform(DWT) module and a bit-plane encoder(BPE). The thesis presents the FPGA logic design of CCSDS-IDC through the introduction of top system circuit architecture.Toward the self-adaptive fault-tolerant design of CCSDS-IDC image compression system,the research shows a high-speed reconfiguration controller with ICAP and an effective error detection mechanism, which target to improve the ability of system fault-tolerance. Simultaneously, we preserve compression module relatively independent. Compared with traditional harden techniques, our strategy features lower resource occupancy, smaller system performance loss, higher fault tolerance performance and flexibility. To save hardware resource, a memory share strategy between compression and fault-tolerant module is realized. Finally, the paper provides SEU simulation platform to emulates deep-space radiation environment and effectively verify fault-tolerant system which is based on the shared ICAP.