We are studying the option to use ADF7021 for (D)BPSK demodulation for an upgrade of a customer design. The current design use discrete RF front-end and demodulation, by the mean of tuner, AGC and fast MCU to demodulate (D)BPSK in the 868M band with low bitrate (100bs and 600bps) and decode frames. While the current design works well it has some drawback, mostly the sensitivity which we cannot get better than -90/-95dBm and the BOM cost which is quite significant with discrete RF front end.
In an effort to increase sensitivity, reduce BOM size / cost and streamline this design we want to use ADF7021 to replace the whole RF front end and hopefully the 100MHz MCU (there is another SoC onboard which could drive the ADF7021 and deal the decoding).
Our main problem is that the (D)BPSK demodulation is not directly supported by the AX5243, that being said it does support ASK and PSK which could potentially be used to demodulate the (D)BPSK.
The other problematic is that we need to scan a 200KHz bandwith for incoming frames, due to the fact frames are randomly sent to 100Hz channels in this 200KHz BW. There is a preamble and the bitrate is low (100bps) so it should be realtively easy to scan the 200kHz BW and detect the preamble in time, such technic is used with other transceivers. Another option could be to get the raw ADC datas (after decimation) to the MCU and use our existing DSP chain to detect the incomming channel and quickly tune the transceiver on it, assuming the ADF7021 is providing such debug mode (which is available on other transceivers) and the adjustable IF filter can be set to 200KHz BW (which seems possible).
Thank you in advance.
typo corrections, formatting
[edited by: Hoel at 2:33 PM (GMT -4) on 9 Oct 2020]