On 22/10/11 09:41 PM, Bonee Soibam wrote: > Hi , > I am trying to measure the RSSI on an usrpn200 which acts as a > receiver. i have used the rx_ascii_dft.py and uhd_fft.py both and i > have made a host of measurements but the received power is not > reliable for different transmit powers at different amplitude of > 0.25,0.50 and 0.85 (which i took randomly ) .. the channel > attenuation is not less for more transmit power in short .. > > Is there any other way to measure the RSSI values besides these two > apps uhd_fft.py and rx_ascii_dft.py ?i have run a set of measurements > and the resultant received powers are not reliable at all ,according > to me . i am still an amateur regarding this . > how about running the rssi.v verilog file ? .. will i be able to > extract the rssi values directly from the fpga ? > > Anticipating your feedback in earnest > Bonee > Received power is proportional to the average of the square of the I and Q voltages. If you use a Complex-to-Mag**2 block, followed by a low-pass filter, you'll get an (uncalibrated!!) received-power estimate.
An increase in *voltage* magnitude from 0.25 to 0.5 should create a received power increase of 6dB, since doubling the voltage increases the *power* by a factor of 4 (6dB), assuming a reasonably linear channel between TX and RX. You haven't said what your test setup is: antennae, daughtercards, etc. What are you using to transmit? Is it another USRP device, or something else? -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
