Basic HORS Satellites Support #722
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| self.slicer = digital.binary_slicer_fb() | ||
| self.deframer = sync_to_pdu_packed( | ||
| packlen=71, sync=_syncword, threshold=syncword_threshold) | ||
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| self.connect(self, self.slicer, self.deframer) | ||
| self.msg_connect((self.deframer, 'out'), (self, 'out')) |
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Is there no CRC, no scrambling, no FEC, no nothing? Just a 64-bit syncword and 71 bytes of packet data?
Is there documentation publicly available about the transmission format used by these satellites?
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Based on the correlation, it has a 64-bit sync word and 71 bytes of data. There is a PN pattern in the data, but since I have absolutely no documentation on these satellites, I don't know the PN generation polynomials. Otherwise, it doesn't have much else.
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I don't know if this is enough to constitute a deframer, especially because there is no way to check for bad decodes without a CRC.
Let me see if I got this right: through reverse-engineering you managed to identify that all the packets start by the same 64-bit sequence (which you are using here as syncword) and following that they have 71 * 8 bits. Moreover, you say that there is a PN pattern, so there might not be any data in these packets, or the data would need to be despread for further processing.
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I hope will get at least some deeper info about packet structure, but it will be good to have ability to demodulate data from these sats
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IQ samples https://www.pe0sat.vgnet.nl/download/HORS/ |
This adds a deframer for HORS satellite data packets