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I am trying to learn aspects of space/satellite communications. So Amplitude-Phase Shift Keying is quite popular in this domain.

APSK over Non Linear channels has worse performance than the earlier used PSK. Which is important because to non linear effects caused by the power amplifier on board. To counteract the effects of non linear distortion, one of the techniques used is Pre Compensation at the modulator.

This involves constellation predistortion. What does this mean?

Does this refer to error control encoding schemes like convolutional coding, tcm, turbo coding etc?

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    $\begingroup$ In very general terms, pre-distortion means altering a signal's shape, so that after it goes through the channel, the output looks like the original signal. So you basically alter the signal by the inverse of the distortion. This is a separate issue from coding. $\endgroup$ – MBaz Aug 1 '17 at 14:44
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    $\begingroup$ @MBaz please copy & paste into an answer – I'd upvote that, since it'd be a short, concise, sufficiently comprehensive answer $\endgroup$ – Marcus Müller Aug 1 '17 at 17:47
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    $\begingroup$ @MarcusMüller You convinced me :) $\endgroup$ – MBaz Aug 1 '17 at 18:15
  • $\begingroup$ I also agree. It is a good idea to resolve the questions if there is a nice answer in the comments. Otherwise, the question will bump up by "community" almost for ever. $\endgroup$ – msm Aug 1 '17 at 18:25
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In very general terms, pre-distortion means altering a signal's shape, so that after it goes through the channel, the output looks like the original signal. So you basically alter the signal by the inverse of the distortion.

This is a separate issue from coding.

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  • $\begingroup$ Sorry I didn't mark this as corrected earlier. I only checked it now. Thanks for your answer. Could you point to any tutorial type sources or texts that discuss these techniques? $\endgroup$ – kchak Aug 3 '17 at 7:23
  • $\begingroup$ @kchak Glad to be of help. This is an intro-level report on this subject: web.wpi.edu/Pubs/E-project/Available/E-project-042407-155515/… $\endgroup$ – MBaz Aug 3 '17 at 13:56

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