The Decoder Of Satellite TeleCommand Based On ASIC

The spacecraft's further demanding to low ower-consuming, high reliability and little weight have not been met by the general integrated circuit (IC) again. Hence, it is emergent that apply the new electronic technology to developing the Application Specific Integrated Circuit (ASIC) for the spacecraft. Considering that, Field Programmable Grate Array(FPGA) is employed on building the telecommand decoder, which applied to the spacecraft telecommand equipment in the system of PCM. And the primary function of the telecommand decoder is channel decoding and source decoding, and so on. To the channel coding, we design two coding methods, one is CRC with odd checking code,and the other is [63,56,3]BCH code. The CRC with odd checking code is the common used code. The [63,56,3]BCH code, in the new standard of CCSDS Packet TeleCommand, is recommended to use. As for the achievement of [63,56,3]BCH Decoding, the Euclidean Algorithm(EA) is employed in it, which is achieved easily with the hardware circuit. Otherwise, The EA is improved in order to simplify the structure of the circuit during the experimentation. In the new method, divisions have been substituted by additions. Therefore, the occupation of the programming resource in the FPGA is reduced largely. Correspondingly, the frequency of the system clock is advanced. From the test, the FPGA realization of spacecraft telecommand equipment can not only obviously diminish the instrument's weight, volume and power-consuming, consequently enhance its performance, but also evidently cut down the developing expense. So, the strategy is valuable to the project practice.