I'm a newbie, but this is the way I understand it. Each ramp (chirp) is made up of 2^SF chips, ranging between fL and fH, with each chip being 1/BW long. That is, the ramp is made up of 2^SF frequencies, from 0 to 2^SF - 1, commonly referred to as 2^n - 1, which results in n bits (or SF bits) transmitted each symbol. That doesn't really answer the question, but I hope it helps understand the answer which is, chip rate is correlated to bandwidth by definition. LoRa basically said, we are going to chop each Bandwidth into 1/BW segments, or chips.
Brilliant job you've explained the concepts really well. I do suggest that viewers first read the Semtech paper on Lora modulation and then look at your videos. Kudos to you.
1. BW = chip rate (chips/s). 2. But the number of chips depends on SF (equals 2**SF). BW and SF are independent - is there a contraction in the first two statements?
Great tutorial thanks ,can you help me to get a view on this matter ,I am using SX1278 module along with ESP32 I would like to know about the Sync Word of the LORA Modules .
So looking at this, the chip rate is the data transmissions per second, which can be expressed in hertz. The signal modulates frequency as well, which is also in hertz? Seems there are two different "hertz" values going on here, though I could be wrong.
Do I understand this correctly, that it takes some time to notice the change in frequency. So if we want to encode twice as many chips into the symbol, we need to multiply time of the symbol by 2? (because receiver would not be able to decode the information if we change frequency too fast?)
Hello, Robert. First of all, congratulations for the extraordinary job. It's much more than just an introduction for beginners. It's a complete manual! Could you explain how to calculate the Time on Air for the transmissions? Thanks in advance.
Hello, I use SF = 7, BW = 125Khz and sending 128 byte. The transmitter takes around 2230 ms from setting the Tx mode till the Tx done, is this right? How to decrease this time?
chips per second? that makes no sense, a chip is a value of a symbol (see chap 13), so is it symbols per second?? and i dont understand how the bandwidth of the signal 125kHz can have linear affect on the symbol rate
Why does BW equal to chip rate?
Love your vids, incredible how much better they are at making me understand. than my own professor
hi Robert, can you please explain why the chip rate corresponds to the bandwidth? in what way are these two correlated?
I'm a newbie, but this is the way I understand it. Each ramp (chirp) is made up of 2^SF chips, ranging between fL and fH, with each chip being 1/BW long. That is, the ramp is made up of 2^SF frequencies, from 0 to 2^SF - 1, commonly referred to as 2^n - 1, which results in n bits (or SF bits) transmitted each symbol.
That doesn't really answer the question, but I hope it helps understand the answer which is, chip rate is correlated to bandwidth by definition. LoRa basically said, we are going to chop each Bandwidth into 1/BW segments, or chips.
I am not sure. I suppose because you have doubled space (bandwidth) to sweep (fit the data), so you have twice the rate.
Brilliant job you've explained the concepts really well. I do suggest that viewers first read the Semtech paper on Lora modulation and then look at your videos. Kudos to you.
Why is the modulation bandwidth equal to the chip rate?
I'm enjoying so much your videos, thanks!
u saved my life, thnk u it really helps
How did you calculate the transmission time for the 10 byte payload for SF7 and SF12?
its 45 and 70 symbols, calculation and transmission time not clear
1. BW = chip rate (chips/s).
2. But the number of chips depends on SF (equals 2**SF).
BW and SF are independent - is there a contraction in the first two statements?
Exactly! I'm also confused about this... Doesn't make any sense
Great tutorial thanks ,can you help me to get a view on this matter ,I am using SX1278 module along with ESP32 I would like to know about the Sync Word of the LORA Modules .
So looking at this, the chip rate is the data transmissions per second, which can be expressed in hertz. The signal modulates frequency as well, which is also in hertz? Seems there are two different "hertz" values going on here, though I could be wrong.
Do I understand this correctly, that it takes some time to notice the change in frequency. So if we want to encode twice as many chips into the symbol, we need to multiply time of the symbol by 2? (because receiver would not be able to decode the information if we change frequency too fast?)
Thanks very informative!
Hello, Robert.
First of all, congratulations for the extraordinary job. It's much more than just an introduction for beginners. It's a complete manual!
Could you explain how to calculate the Time on Air for the transmissions?
Thanks in advance.
I have explained it in tutorial 17, see ruclips.net/video/C_Rh5GSENA4/видео.html
thank you, it's very helpful.
32 byte packet at SF12 gives 45 symbols, how they are calculated? thanks in advance
Thank you, what about if I use this formula (Rb (bits/sec) = SF x (BW / 2^SF) x (4(4+CR)) to find the throughput?
thanks for this tutorials, very helpful.
in 5:00 you mention an increment of distance related with the ToA increment, what does that distance mean?
Hello,
I use SF = 7, BW = 125Khz and sending 128 byte.
The transmitter takes around 2230 ms from setting the Tx mode till the Tx done, is this right? How to decrease this time?
how do you calculate the trasmission time with 10 bytes payload.
Haha I can't believe I understood that. Nice.
chips per second? that makes no sense, a chip is a value of a symbol (see chap 13), so is it symbols per second?? and i dont understand how the bandwidth of the signal 125kHz can have linear affect on the symbol rate
Thank you so much
How long does it take for one symbol to be transmitted?
Sorry I do not know. I have found this, but this is beyond my skillset: repository.kaust.edu.sa/bitstream/handle/10754/655888/08723130.pdf
I found this video to be unclear. Great video btw, thank you very much!
It's chirp, not chip. But great video anyway. Thank you.
The video is correct. Chirps are frequency ramps (up or down) which define symbols. A symbol holds 2^SF chips which defines the bandwidth.