[Discuss-gnuradio] A basic USRP2 + BBN receiver + Samples_per_symbol que
[Discuss-gnuradio] A basic USRP2 + BBN receiver + Samples_per_symbol question + An observation
Fri, 26 Nov 2010 16:15:08 -0500
Hello list, I have been fiddling around with USRP2 version of BBN code for a week now. First, one observation I found is: if and only if I set decimation to 4 (i.e., 25Msps), I see almost all of the 1Mbps packets sent by my 802.11 sender. This includes data packets (1400 bytes payload), and
IEEE802.11 association/reassociation request packets. I wonder why?
My setup: - Infrastructure mode - AP has a fixed data rate set to 1Mbps so that BBN code receives *ALMOST* all the packets
Now, onto my MAIN question: - If the sender at 1Mbps is using DSSS (Barker code), and I am receiving with decimation factor 4 using USRP2, - How many samples per symbol should I expect (I am assuming 1 symbol per bit, thus samples per symbol = samples per bit)? I collect samples using usrp2_rx_cfile.py [rx-file=b.dat] and analyze in Matlab.
- So, 25MSps (complex float symbol) sampling rate, how many samples per bit ought I expect. I do b = read_complex_binary('b.dat') in matlab , and look at plot(abs(b))?
Thank you in advance for your time.
[Prev in Thread]
[Next in Thread]
[Discuss-gnuradio] A basic USRP2 + BBN receiver + Samples_per_symbol question + An observation,