Spreading factor of CYRF6936 LP radio

Question: What is the Spreading factor of CYRF6936 LP radio?

 

Answer:

The spreading factor = S.B.W (Spreading bandwidth)/(Frequency equal to the transmission rate of the modulation signal).

The symbol rate is 31.25 KS/sec for 250 Kbps data rate. According to the timing chart it takes 32 uSec for transmitting 250 Kbps. That means the symbol rate is 1/32uSec = 31.25 K Symbols/Sec. Therefore the frequency equal to the transmission rate of the modulation signal = 31.25KHz. The spreading bandwidth of the WirelessUSB LP radio = 1.04 MHz. Hence the

Spreading factor = S.B.W (Spreading Bandwidth) / (Frequency equal to the transmission rate of the modulation signal)

Spreading factor = 1.04 MHz/31.25 KHz = 33