[SOLVED] Does the 470MHz LORA work with 30ppm freq error?

[tony_lth]

Hi, Gurus,
There is an issue confused me for a while.
Now the XO of the 470MHz LORA design is a 32MHz TCXO with about 1ppm error, so the RF freq error is also about 1ppm.
But I want to replace the 32MHz TCXO with a normal 32MHz crystal, which has about 20ppm freq error.
The issue is that the 470MHz LORA may be a node for the LORA netwrok, i.e., as a similiar base station to receive several hundreds sensors data in TX/RX mode.
So the node 470M LORA should have a sync function, and I think the sync function should be based on the baseband processing and doubt if it is related to RF freq error.
I don't know the protocols of LORA networks, so any Guru think it is possible to replace the 32MHz TCXO with a normal XO?
Attachments are the 32MHz TCXO datasheet and related LORA documents, for the reference.
Best,
Tony Liu

--- Updated Mar 22, 2021 ---

PS: The 32MHz TCXO is working for Smetech LORA 1268 RF IC.
There is another 8MHZ XO(20ppm) for the STM32 IC as the baseband crystal.

 

[vfone]

According to IEEE standard page 421: "the BPSK PHY transmit center frequency tolerance shall be ± 40 × 10^-6 maximum."
Which means that at 470MHz the TX frequency accuracy should be about 0.2ppm.
If the transmitter is part of a sync loop, may handle this frequency accuracy without using a such accurate reference frequency (the same as many of cellular systems does). This may be possible because LoRa use geolocation.

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