|From:||Kyeong Su Shin|
|Subject:||Re: [Discuss-gnuradio] Confusion about Sample rate|
|Date:||Sat, 1 Jun 2019 17:40:55 +0000|
Sampling rate of the system can affect the performance of a such system (depending on the performance matrices that you use). Here's a simple example:
Let's say someone is transmitting WiFi signals over the air. Due to the multipath fading, some portion of the spectrum is more attenuated than the other part of the spectrum (in the frequency domain). If your receiver is sampling at a slow sampling rate (significantly lower than the Nyquist rate), and happens to be at the attenuated side of the spectrum, then it may miss the transmitted signal. That would not have happened if the receiver sampled at the full rate.
Now, the reality is not that simple (for one thing, the effective bits of USRPs may increase when you configure it to sample at a lower rate, because it can actually sample the signal at the full rate and then decimate on the FPGA; that is how most real-world receivers work), but various factors like this can effect the probability of detection, false alarm, or the detection speed of the spectrum sensing system.
Kyeong Su Shin
보낸 사람: Jiji Varghese <address@hidden> 대신 Discuss-gnuradio <discuss-gnuradio-bounces+address@hidden>
보낸 날짜: 2019년 6월 2일 일요일 오전 12:35:40
받는 사람: Marcus D. Leech; address@hidden; address@hidden
제목: Re: [Discuss-gnuradio] Confusion about Sample rate
Thank you for the responses.
I was planning to use USRP B200 which allows a BW of 56MHz.
> On 06/01/2019 02:03 AM, Kyeong Su Shin wrote:
>> To whom it may concern:
> >> ________________________________
>> 보낸 사람: Marcus D. Leech <email@example.com>
대신 Discuss-gnuradio <firstname.lastname@example.org>
>>> I am trying to store WiFi signals samples in a file using file sink block, using GNU radio, for spectrum sensing. I know that a single WiFi channel has a bandwidth of 20-22 MHz. So should I use the sample rate in GNU radio block to 40e6 - 44e6
or can I use a lower value? Can I use 1e6 as sampling rate?
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