Can anyone in the know comment on what modulation technology DJI use.
I had assumed it was spread spectrum modulation (SSM) because it is 2.4Ghz and that seems to be the norm for that frequency these days. Also, the transmitter has to bind to the receiver - which suggests they are agreeing on a PN code pattern for the dialogue - which fits with SSM.
However, something has been nagging away at me since I noticed a recent RC transmitter f/w update whose description referred to the "PPM link". Pulse Position Modulation is quite old (30+ years I think). I have read that it was superseded by Pulse Code Modulation which in turn was superseded by the 2.4Ghz SSM group of protocols. These narrow band methods (PPM/PCM) are prone to interference from other users on the same frequency. So I am curious why they would use the term PPM in the description of the firmware update.
Can anyone clear up what DJI use for their modulation?
Thanks
I had assumed it was spread spectrum modulation (SSM) because it is 2.4Ghz and that seems to be the norm for that frequency these days. Also, the transmitter has to bind to the receiver - which suggests they are agreeing on a PN code pattern for the dialogue - which fits with SSM.
However, something has been nagging away at me since I noticed a recent RC transmitter f/w update whose description referred to the "PPM link". Pulse Position Modulation is quite old (30+ years I think). I have read that it was superseded by Pulse Code Modulation which in turn was superseded by the 2.4Ghz SSM group of protocols. These narrow band methods (PPM/PCM) are prone to interference from other users on the same frequency. So I am curious why they would use the term PPM in the description of the firmware update.
Can anyone clear up what DJI use for their modulation?
Thanks