Hi guys,
I transmit packets by cc1350 launchpad of Texas instrument with Long Mode Range , mode 1 or 2, lets assume I use legacy mode which it's mode 1
in the link here there's an explanation about protocols and encoding schemes of mode 1 and mode 2 : https://www.ti.com/lit/an/swra642/swra642.pdf
and Im sampling them (capturing the packet) by a dongle called RTL-SDR.
I've succeeded to see the my sampled packet (transmitted packet) as I've built demodulator also fec encoder.
what Im trying to understand is how bits after it outs from fec encoder and enter the Direct Sequence Spreader how will it be transmitted ?
For instance lets assume that the output data of my fec encoder is [0 0 1 0] so it will be fed through DSSS , lets assume in my case the value of my DSSS=8 , so what should be the output of DSSS? I understand it should be in terms of 11001100 , 00110011 according to DSSS table that attached in the link above under encoding scheme.
So if we fed DSSS with [ 0 0 1 0] the output of DSSS is 11001100110011000011001111001100 am I right? Im asking because Im getting confused in the notation that's mentioned under Direct Sequence Spreader table in the link attached above- it's written LSB first for every sequence and didn't understand it well.
Second question, about Mode 1- Legacy Long Range Packet Format it's shown in the link that the payload data size is :
N*8*2*DSSS symbols
So it's showing the total size of payload after stage of DSSS .. right? I mean , the size of payload N*8*2*DSSS is actually the payload data after it passes the stage of Direct Sequence Spreader , in other words the size of payloads in terms of DSSS ... right? thanks alot.
I transmit packets by cc1350 launchpad of Texas instrument with Long Mode Range , mode 1 or 2, lets assume I use legacy mode which it's mode 1
in the link here there's an explanation about protocols and encoding schemes of mode 1 and mode 2 : https://www.ti.com/lit/an/swra642/swra642.pdf
and Im sampling them (capturing the packet) by a dongle called RTL-SDR.
I've succeeded to see the my sampled packet (transmitted packet) as I've built demodulator also fec encoder.
what Im trying to understand is how bits after it outs from fec encoder and enter the Direct Sequence Spreader how will it be transmitted ?
For instance lets assume that the output data of my fec encoder is [0 0 1 0] so it will be fed through DSSS , lets assume in my case the value of my DSSS=8 , so what should be the output of DSSS? I understand it should be in terms of 11001100 , 00110011 according to DSSS table that attached in the link above under encoding scheme.
So if we fed DSSS with [ 0 0 1 0] the output of DSSS is 11001100110011000011001111001100 am I right? Im asking because Im getting confused in the notation that's mentioned under Direct Sequence Spreader table in the link attached above- it's written LSB first for every sequence and didn't understand it well.
Second question, about Mode 1- Legacy Long Range Packet Format it's shown in the link that the payload data size is :
N*8*2*DSSS symbols
So it's showing the total size of payload after stage of DSSS .. right? I mean , the size of payload N*8*2*DSSS is actually the payload data after it passes the stage of Direct Sequence Spreader , in other words the size of payloads in terms of DSSS ... right? thanks alot.
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