• TI Thinks Resolved

AFE7070: CPFSK using AFE7070

Prodigy 80 points

Replies: 2

Views: 116

Part Number: AFE7070

Hi,
I am planning to develop modulated transmitter for telemetry purposes.

The current goal is to provide both frequency modulation and phase modulation from the same hardware depending on the type of modulation selected by user. The types of modulation currently selected are Basic FM (CPFSK) and QPSK. Now if the user selects QPSK then, then the use of AFE7070 looks fine where we can feed the data in the form of I and Q in TDM format and the internal modulator will take care of the complex modulation functionality.

But I am quite confused on how to achieve CPFSK using the same hardware. Can I send just info data in one of the channel and send equivalent bit 0 on other channel? Can you please direct me to any link or any support document where I can take reference  for this issue? 

Thanks!
Mandan

  • Mandan,

    We are looking into this.

    Regards,

    Jim

  • In reply to jim s:

    Hi Madan,

    IQ Modulation is used to suppress the side band at the output.In both cases (QPSK and CPSK) you would be using Hilbert transform to generate complex data and by using complex data you will only see single side band and the image will be suppressed. 

    Regards,

    Neeraj