I would like to know what is the modulation technique used on the New Horizons Spacecraft? Is it BPSK or GMSK? Also what is the coding technique-turbo-codes or LDPC codes? And do you have a link budget available?

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    $\begingroup$ 2 of your 3 questions are answered here: space.stackexchange.com/questions/7776/… $\endgroup$
    – Hobbes
    Jul 15, 2015 at 12:24
  • $\begingroup$ @Hobbes - the linked question does not directly deal with modulation, I'd be loath to close this one as a dupe. It is too broad, though. $\endgroup$ Jul 15, 2015 at 12:49
  • $\begingroup$ Irving, please choose one specific question instead of three, bearing in mind the link posted by @Hobbes. $\endgroup$ Jul 15, 2015 at 12:50
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    $\begingroup$ @Deer Hunter: Phil Karn's answer to that question contains the data Irving's looking for (BPSK and turbo-coding). $\endgroup$
    – Hobbes
    Jul 15, 2015 at 12:59

1 Answer 1


Phil has explained it nicely. Yes, it is BPSK with R=1/6 Turbo coding, that is used in New Horizons. Some aspects of the X band digital receiver used is discussed here. For the coding enthusiasts, I can add that the Blocklength is k=1784 bits (even though it is programmable, for low data rate support, this minimum block length is used). The information code length (post coding) n =(k+4)/R=10728 bits.

  • $\begingroup$ Welcome to Space.SE. This is a very interesting information. However it covers the uplink receiver, not the downlink transmitter which is the topic in the question. Any chance you can get a similar paper? $\endgroup$
    – mins
    Jul 19, 2015 at 23:07
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    $\begingroup$ The turbo coding is in fact for the downlink. The uplink is not coded. $\endgroup$
    – Mark Adler
    Jul 20, 2015 at 0:30
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    $\begingroup$ Thanks for the info. I thought Phil had mentioned the DL reference circuit link already. Yes I was referring to the DL (Turbo coding). That is where the most critical/precious data (e.g., image data) is coming. Also, the most sophisticated of the receivers (turbo decoder, synchronization to name a few) can be implemented in the ground than in the space station. $\endgroup$ Jul 20, 2015 at 2:01

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