RP as a IF SDR for a pulse-doppler radar

[gralves]

Hello,

I have been studying the digital processing of pulse doppler radars and I would like to know if anybody has ever used the Red Pitaya as a digital IF receiver for a coherent on receive pulse-doppler radar. Do you think RP hardware is enough to do the following processing?

- After a trigger, the radar transmits an RF pulse of very short duration (1-3 us). The RF pulse will be generated by an external generator. This trigger is generated with a 0.5~5 kHz repetition rate.
- There are two RF signals, one is the transmitted signal and the other is the received signal. An external heterodyne receiver converts the RF signal to the IF frequency of 30 MHz. The signal in baseband has about 2 MHz of bandwidth.
- The dynamic range of the received signal can be around 100 dB, my application can work with an external controlled attenuator that can reduce this requirement
- The RX signal is acquired after each pulse. The acquisition starts after a fixed time of the trigger and stops after a certain number of samples is acquired.
- The TX signal is acquired in a similar way as the RX signal but with different start time.
- The RX signal is correlated with the TX signal producing I and Q signals that are filtered and downsampled to baseband (around 2 MHz bw)
- The I/Q signal is sent to external hardware as a UDP stream.

I understand that in order for the RP to be able to do this I would have to reprogram the FPGA and probably write new device drivers. Is there any documentation on how to do this for the RP?

Thank you,

[pavel]

Several of my Red Pitaya projects have quite similar functionality. You can find them at the following link:
http://pavel-demin.github.io/red-pitaya-notes/

I'm trying to keep my projects as simple as I can and they don't require any new drivers.

If I'm not mistaken, one of the following to projects could be a good starting point for your system:
https://github.com/pavel-demin/red-pita ... radar_test
https://github.com/pavel-demin/red-pita ... _no_filter

They decimate and record a fixed number of samples after a trigger. The missing multiplication by a 30 MHz complex sine wave could be taken from one of the SDR projects.