Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [usrp]

38 questions
6
votes
2 answers

GnuRadio RF transmission, legal and safety issues

I'm trying to run some transmit/receive RF examples that I found online using GNU Radio with USRP B200. I read and heard about some cautions in terms of transmitted frequencies here in the USA which made me slow down! What is the legal frequency…
Hadad
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6
votes
2 answers

Advantages of IQ generation at Mixer Stage or within FPGA for SDRs

I draw two possible architectures for Software Defined Radios below. In the first architecture, I,Q signals are generated at the mixer stage and two ADCs are required. The FPGA down-samples the samples from ADCs and forwards them the USB PHY.…
Denis
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5
votes
2 answers

What cause the spectrum peak of `center frequency`?

I use gnuradio and fosphor to view the spectrum from USRP B210, default gain set to 34, output looks like concave as below: Nothing changed just set gain to 35, output become flat, looks like convex: Whatever center frequency I set,0 frequency…
kittygirl
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3
votes
1 answer

USRP: Are RX and TX on the same or different channel for single daughterboard?

I've got a USRP X310, currently with just one daughterboard, a WBX-120. I'm writing some C which needs to operate the radio full duplex - I receive on RF A RX2 and transmit on RF A TX/RX. But I'm confused as to how I identify which number channels I…
Walkingbeard
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3
votes
1 answer

GNU Radio - Frequency parameter of Signal Source Block

I designed an analog FM transmitter with GNU Radio Companion in order to understand the tool better. The hardware I use is an USRP B200. The carrier was built with a Signal Source block and the baseband was obtained from a .wav file. The last block…
karstarkastro
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3
votes
2 answers

USRP Safe Gain Values

I am working with USRP N210 and USRP B200 radios with GNURadio. I have connected the TX/RX port of one radio to the RX2 port of the other with an RF cable as a simulated radio link. In GNURadio, I have been setting my transmitter gain and receiver…
rytse
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3
votes
1 answer

How high an SWR can the USRP 2901 (B210) handle?

I connected a USRP 2901 (B210) to an amplifier I designed. The USRP seems to shutdown every time I try to transmit. I guess I messed up with the input impedance matching on the amplifier. Is it the impedance mismatch that is causing the USRP to…
user11096
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2
votes
1 answer

How can I make WBFM receiver without using WBFM Receive block?

I'm trying to make a WBFM receiver without using WBFM Receive block. So I've tried this way But it won't work. The problem is RuntimeError: flow graph has loops! and I need to use loop feedback for implement FM demodulation. Very pleasure for…
Yondonjamts Ganzorig
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2
votes
1 answer

Choose the right dongle for NOAA images visualization with GnuRadio

I'm a newbie in such domain and I was reading some articles around the internet and what attracted me most is using the GnuRadio to see NOAA images using some cheap hardware. I looked further it turned out that this cheap hardware is only for…
A.nechi
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2
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0 answers

Why the Receiver Sensitivity theoretical value doesn't match its experimental value when using USRP B200mini in GNU Radio?

I'm using a USRP B200mini SDR card for my GNU Radio energy detector project. I wanted to measure its Receiver Sensitivity ($RS$) experimentally and compare the experimental value to the theoretical value. Assume the minimum needed Signal to Noise…
HadK
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2
votes
1 answer

USRP-B210 GPSDO will not lock

Hi I own a B210 and I have a GPSDO that's installed but I do not have the antenna yet. Can I use it as a 10MHz reference and PPS until I obtain the antenna?
ShaneT
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2
votes
3 answers

What cause the shape of frequency spectrum convex or concave?

I use gnuradio and fosphor to view the spectrum from USRP B210, default gain set to 34, output looks like concave as below: Nothing changed just set gain to 35, output become flat, looks like convex: What cause the shape of frequency spectrum…
kittygirl
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2
votes
2 answers

Output power from the TX/RX port of the USRP N210 decreases as the frequency increases

I am trying to build an FMCW radar using a USRP N210 with a CBX40 daughterboard. I generate a sweep from 1.5GHz to 5GHz. According to their respective datasheets, the daughterboard and the USRP should work fine up to 6GHz. However, as the frequency…
Fati
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1
vote
3 answers

Viewing the broadcast FM spectrum using a USRP N210

My issue is regards to viewing the FM spectrum using USRP N210 & GNU Radio. I did try to use several blocks of GNU Radio to view an FFT plot of the FM band using the USRP N210 device. My blocks and results are as below, I used my mobile phone to…
Denis
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1
vote
2 answers

Phase detection accuracy with USRP N210 and CBX-40

I have designed a simple TX/RX system in GRC with a single USRP N210 and CBX-40. I am transmitting sinusoidal signals at various frequencies within the 2-6GHz range and detecting the amplitude and phase of the received signals at each frequency when…
Fati
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