A powerful forward error correction (FEC) scheme based on the serial concatenation of Bose-Chaudhuri-Hocquenghen (BCH) and low-density parity-check (LDPC) codes has been adopted by the second generation digital video broadcast (DVB-S2) standard due to their near Shannon limit performance. This paper proposes an efficient FEC encoder core to support different DVB-S2 codes for variable coding modulation (VCM) schemes of low earth orbit (LEO) satellite-ground communications. By exploring the properties of different concatenated BCH-LDPC codes and reusing the computation units and memories, the compatibility is achieved and the utilization of hardware resources is improved. Besides, parallel computing is performed to speed up the acquisition of check bits, which allows the encoding throughput to be increased. Hardware architecture implementation on Xilinx XC7K325t field programmable gate array (FPGA) shows that the encoding throughput rate of the proposed FEC encoder core can reach 1.19 Gb/s. And the overall data throughput is improved by 30.9% compared with the constant coding modulation (CCM) schemes.
ASIC (Application Specific Integrated Circuit) technology is mature and widely used in many fields. It is a trend to integrate some common spacecraft engineering requirements into one chip to take the place of FPGA and some digital chips, which can miniaturize spacecraft avionics and reduce the repeated work for spacecraft engineers. Based on the analysis on small satellites application requirements, the system design of an ASIC chip for spacecraft data system is proposed. Firstly, the chip system architecture is described. Secondly, four key technologies of the ASIC chip design are presented in detail. They are the design of the chip's operating modes, the design of IP cores, the design of reliability, and the design of low power consumption. Generality, adaptability and independent intellectual property make this ASIC different and special from other space chips. Four operating modes are optional: 1553B bus control mode, PCI control mode, ISA control mode, internal CPU control mode. Besides, there are 1553B bus protocol IP cores, CAN bus interface, and abundant peripherals, which can satisfy most of the routine engineering requirements in small satellites. Finally, the chips status and some promising applications are described.
To meet the demand for aerospace applications, high-speed computing transcendental functions such as trigonometric functions, we design a high-speed full-parallel CORDIC processor. On this basis,combining the optimized algorithm of simplifing pathway and adding-bits high-precision method , the original design has been improved. The experimental results show that improved design reduces hardware overhead compared to adding-bits high-precision design,and improves accuracy compared to fully parallel design. This high-speed fixed-point CORDIC has high precision and is suitable for high-speed applications in computing trigonometric and inverse trigonometric functions.
Space borne high-capacity solid state recorder (SSR) is an inevitable chain of the space scientific data acquirement system. It has become a common device in spacecraft gradually. This paper presents the design and accomplishment of the large capacity SSR design based on NAND flash of the satellite SJ-10. The SSR improves its writing speed significantly by applying multi-pipeline writing technique. External SDRAM is used as the channel cache of the multi-channel data flows to increase the cache capacity and system throughput speed. In addition, the EDAC processing, data flow combining and separating can enhance the stability of the storage system as well as the data efficiently. The implementing of multi-channel has also laid the foundation for file system management of the space borne storage data. The simulation of multi-channel data flow is given in this paper.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.