-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Vanush,
good question, actually. The point here (that I try to highlight whenever a question about received signal strength / RSSI / RX power requirement comes up) is that received signal strength is so much depending on what you are trying to measure, and how you go about to do that. Although I agree that something like a table saying "tuned to 1.284GHz, for the daughterboard YMCA in revision 42 in combination with the onboard ADC of the ettus b430 USRP, sampling a expensively generated noise that looks white for the complete ADC bandwidth, for which the perfectly matched signal generator proclaims that the accumulated power is -15dBm, should yield, given the following combination of filter and sampling rate settings, an average magnitude of 0.2-0.3, assuming that you have self-calibrated the USRP well enough" can be useful - but only if your application looks similar enough to the benchmark; which it usually won't. These tables will be big. And of limited helpfulness - in the end, the user has to calibrate things himself; if there is no high-end equipment at the user's site, then there's no way to measure e.g. matching of antennas, quality of cabling... However: Medhat, you just said the results were "inaccurate"; maybe if he elaborated on that, we'd know what you were trying to measure. In fact, the results of avg_mag_sqrd are accurate to the point of numerical accuracy if you're measuring the average numerical power of the digital domain sample -- but I do get the feeling that is not what you're trying to do. Greetings, Marcus On 26.03.2014 13:29, Vanush Vaswani wrote: > Is there any reason that this isn't done at a few frequencies > during manufacturing and provided in the datasheet? I've noticed > this with a few SDR's. Surely, it would provide a ballpark figure > for those who could not afford expensive test equipment. > > > On Wed, Mar 26, 2014 at 11:21 PM, Marcus D. Leech > <[email protected]> wrote: > >> On 03/26/2014 07:04 AM, Medhat Hamdy wrote: >> >> Hi all, >> >> I need to know if there is any method to measure the received >> signal power using USRP N210. I am using >> gr_probe_avg_mag_sqrd_x_0 to measure the signal strength, >> however, the results are not accurate. >> >> Thanks >> >> >> >> >> _______________________________________________ Discuss-gnuradio >> mailing >> [email protected]https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> >> To get accurate readings, you have to calibrate with an external, known, >> source. >> >> >> >> _______________________________________________ Discuss-gnuradio >> mailing list [email protected] >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> >> > > > > _______________________________________________ Discuss-gnuradio > mailing list [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTMs0QAAoJEBQ6EdjyzlHtN7cIAI9gH3BlTwhAlbu/lNT9/SlD 7QPgtztf9/ywy9Ark5yjO+ncZExEEzqk/xrLn63mhGDYp4q1aWLywZldjcxDjcJm TYLyNobM6VQZFz3yShaoYwPWtq+QcMftDIC+lEJulVG8vv3ZYBXiq8A0wBwpCNEc Bfi9kWGTB2K5kBhn9w0iEyWimfJELMvxfuwPhrdpvbNSS8MQdDlieGiu/LURHmTf mCDBMplRIbQMDLczx+1oVKkP/prLJfpQBgetgglcEVdSBZ59VmTM4FrzfT7Q8sNN x91bYAKxfUDTa7f6swcKRW+wGUsbWmAw7/7Lm6afQkbcmczXNwC33c+8FxZrTsc= =wM2W -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
