how to understand the transmission time on air?
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hey guys,
i am studying LoRa recently.
In sx127x Datasheet, it says the lora phy frame is consist of preamble, header, payload, and payload crc.
especially, the header is within a code rate of 4/8.
But in the calculation of Time on Air,
it says, nPayload = 8 + max(ceil((8PL-4SF+28+16CRC-20IH)/4(SF-2DE))*(CR+4),0)
how to understand the calculation of the payload?
is the 20IH means the length of the header?
but header is within a code rate of 4/8, isn't it?
why we calculate the header and payload together within the same code rate?
I would be grateful if someone could help me.
Thanks for the question however your question does not look to be an issue or question specifically related to this project.
Your question is a general question about the LoRa modulation and radio chips datasheets.
I would recommend that you ask your question on Semtech LoRa Developers Forum being a more suitable place to ask questions.
Please use the forum search as I pretty sure that your or similar question has already been answered.