Questions tagged [sdr]
Software Defined Radio is a technology for doing radio signal synthesis and demodulation/analysis using software.
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Adalm Pluto SDR - Second RX channel signal issues
I have a Pluto SDR rev c, on which I just enable the second TX and RX channel. I am sending a simple sinusoidal signal at a specific frequency (fc), but different phase and amplitude, using the two TX ...
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Finding device Tx frequency with Yardstick One
I wanted to get into RF hacking (to decode and reproduce ceiling fan control), and decided to buy a Yardstick one. After having played with the YS1 for a while I now better understand that it is NOT ...
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SDR Bandwidth and sample rate
I saw that SDR has two parameter: bandwidth and sampling rate. I would like to know the difference between them because i saw a 56MHz bandwidth SDR but by looking at the chip used inside the sampling ...
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USRP N310 frequency range
USRP N310 uses AD9371 RF transceiver but it has more wider frequency range. The AD9371 tunable range is from 300 MHz to 6000 MHz, but the N310 with 10 MHz to 6 GHz extended frequency range. Why?
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Reverse engineering key fob RF signals
I have been trying to decode the signal of a keyfob with a cheap 315MHz RF receiver (XY-MK-5V) and a ...
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Calculating AC-Coupled input current
I'm using an SDR which uses and ADF4002-based PLL with its REFIN input AC-coupled via a 0.1 uF capacitor to an external input. I'd like to connect an external reference clock to it, but I'm unsure how ...
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Can I use an SDR to transmit on the ISM band without a license?
I would like to use my SDR to transmit arbitrary data.
Can I freely transmit in the ISM bands without any license, as long as I abide by the regulations? My understanding is that I can transmit at up ...
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Mixers and LO Harmonics
Say we have an RF signal with components at \$F_{LO}+\Delta\$ and \$3F_{LO}+\Delta\$ and we want to down-convert so that \$F_{LO}+\Delta\$ becomes \$\Delta\$. We will mix this RF signal with our local ...
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Align symbol period in GFSK communications
To learn more about communication systems I have been using an SDR (RTL2832U) and a 918 MHz transceiver (RFD900+) which sends signals using 2 GFSK. The deviation of my RFD900+ from the center ...
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Monopole antenna integration
When using whip style monopole antennas (similar to those found on a Baofeng push to talk radio) as feeds for software defined radios, what “quality” of ground plane is required for best performance? ...
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CANFI compatabilty with the rtl-sdr R820T
Is CANFI compatible only with the devices mentioned in documentation? It means that there is no opportunity for it to establish connection with rtl-sdr R820T?
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FSK Modulation using I/Q
Is it possible to do FSK with I/Q data? If I/Q only shows amplitude and phase changes is there anyway I can use it to generate a frequency f1 to represent binary 1 and f2 to represent binary 0?
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Connect mobile devices with coax cable to SDR boards
My goal is to connect mobile devices using a coax cable with a SDR board to be independent from using the air interface and antennas. I don't know how to connect my devices with the DSRs.
I have two ...
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Homodyne receiver bandwidth
I understand that most, if not all, SDRs use direct conversion, since an SDR can receive several channels simultaneously. So how does tuning the VCO work?
Let's assume for simplicity that I need to ...
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Demodulation of IQ signals from SDRs
I am writing a Python program for an SDR in which I need to process the signal that the SDR will receive. My problem is that the SDR provides an array of complex values, which is tantamount to using ...
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How to decode TPMS FSK signal on Universal Radio Hacker
I am capturing the TPMS sensor transmission in URH, but i am having extremely hard time to decode correctly the signal.
I know exactly what is the data string that my real sensor is transmitting and i ...
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How to manage multiple devices connected to the same antenna?
I'm planning to connect an SDR in 'parallel' to a modem used to transmit and receive a radio signal on 2.4/5.8 GHz.
The SDR that I want to use is the HackRF one, which can receive up to -5 dBm in ...
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Do you need to smooth (make more sine) the signal of a crystal oscillator or MEMS oscillator?
As I understand it a MEMS oscillator will output a square wave and a crystal oscillator will output a kind of triangle wave. The question is when you mix RF with an oscillator signal to produce the IQ ...
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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 ...
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Is it possible to couple Tx signal to RTL-SDR Rx signal for a FMCW radar?
Above one can see a typical (AFE) diagram for a FMCW. Other block diagrams I found include the processing blocks and and so on as well, but my question rests on the following: can I mix the TX and RX ...
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Name of RF demodulation technique using a demultiplexer
I can't remember the name of a demodulation technique I read the whitepaper on. My memory is not exact but I remember the following vaugely:
Core to it is a 1:4 demultiplexer run at 4x the desired ...
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GNU radio FRS transceiver
I am trying to implement the transmit section of this GNU Radio transceiver design, documented here.
This design is intended for a bladeRF SDR, but the hardware available to me is the USRP B210.
The ...
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Transmitting high-speed PWM over RF
First, let me apologize in advance if this isn't the correct exchange to post this question on.
I have a 50 MHz PWM signal (it's actually a 50 MHz 50% DC clock with a 1PPS clock embedded with PWM) ...
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Need help with modding HackRF One RTL-SDR card with right amp
I'm trying to modding HackRF One RTL-SDR card, regarding this RF amplifier can be damaged the card has problems with TX below 100 MHz, lots of users complain about burning the MGA-81563 chip on board, ...
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How could you determine the point in time a Radar antenna is directly facing a stationary RF receiver station?
I am currently doing experiments involving Software Defined Radio and Radar systems. Since I am new in this field and currently try to refresh my physics/math skills, I encountered some problems along ...
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Carrier Waves, modulation over RF vs on wire
I’m reading about carrier waves and signal modulation. It appears signaling has differences over RF vs wire. RF requires accelerating charges to induce a voltage change at the receiver. Straight wire ...
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119
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Noise factor in homemade software-defined GPS receiver
I'm building a homemade software-defined GPS receiver. I'm currently at a point where I can acquire and track strong signals but struggle to even detect weak signals.
I've ruled out problems with my ...
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SDR output to TV input -- besides impedance matching?
I'd like to connect the output of my software defined radio card, which is 50 ohms SMA, to the antenna input of a TV, to experiment a bit with signal generation.
The obvious problem is going to be the ...
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When multiple cognitive radios transmit simultaneously
Cognitive radio nodes sense the spectrum and start their transmission opportunistically when the spectrum is found to be vacant. The question arises what if two or more nodes find the spectrum to be ...
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Getting started with Radio design [closed]
For a while now, I have been exploring many RF, communication protocol and radio etc. I am kind of looking for a way where i can implement the software stack for a particular open Radio. Means like ...
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How to achieve good receive SNR with FDD outdoor?
I'm trying to set up an eNB with srsRAN for outdoor usage in a small area with a USRP B210 SDR as RF frontend. To this aim, I'm using two amplifiers: MiniCircuits ZX60-V63+ PA in TX and ZX60-33LNR-S+ ...
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Timing Diagram - HyperBus - HyperFlash - HyperRAM - RWDS - CLK - DQ
I'm trying to design an interface between an application processor and a HyperFlash memory from Cypress. Therefore, I'm trying to understand the timing diagram for RWDS and DQs relative to the CLK ...
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Decoding a 433 MHz energy monitor
I am attempting to capture transmissions from my own energy monitor, a Watts Clever EW4009 for use with Home Assistant.
I believe it is an FSK signal, with 250 um packets.
I have captured several ...
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Use Tx port on SDR for an LO?
Designing a receiver for an experiment. The receiver will be in remote location and I will be deploying multiple in the field so have a cost-effective, self-contained system is a priority (is it ever ...
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Definition and Purpose of LFTX / LFRX in SDR Hardware?
I currently cannot find a definition of the LFTX / LFRX blocks that have been drawn in a diagram involving the software-defined radio model USRP N-210. They seem to have been included as input / ...
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what exactly prevents my smartphone from being used as an SDR without a dedicated dongle
The answer seems obvious (frequencies restricted by chips) but I'm looking for a clear and accurate explanation. Several examples of SDR projects connecting an SDR dongle to a smartphone are available ...
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Constellation of BPSK doesn't look as expected
I'm a total novice when it comes to RF beyond basic concepts.
I'm trying to use a HackRF One to pull the data coming off of this transponder, which theoretically transmits data on a 3.59MHz carrier.
I'...
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400Mhz frequence HackRF One
All,
Sorry but I am new to this topic and have no experience with SDR myself.First, I briefly give the hardware that I am using:
HackRF One
Following antenna: https://zsecurity.org/product/atheros-...
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4
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147
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Building an FM transceiver
As an electronics hobbyist, I've already built a thing or two so this didn't seem like a complicated thing to do, but I was terribly mistaken. I wanted to build an FM modulated radio transceiver ...
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315
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What sampling rate is needed for demodulating and decoding GPS signal data?
I just got a software-defined radio (SDR) and am trying to record GPS frequency (L1 1575.42 MHz). I understand that GPS is modulated using Binary Phase Shift Keying. I also read about the Nyquist ...
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Can software defined radio be used as noise generator?
I'm working on solving an issue in a metal detector that generates false detects when subject to electrical interference.
The electrical interference usually stems from devices such as shortwave radio ...
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IQ modulation and phasors: which first?
Do we use IQ modulation because quadrature signals are a good physical implementation of phasors - or is it the other way around?
To elaborate a little:I'm having a hard time getting a clear ...
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Calibrating RTL-SDR Power with 50 Ohm Load and Thermal/LNA Noise
Ultimately I'm generating some spectrum plots in L-Band (1200-1800 MHz) and I need to get calibrated flux units (dBm/Hz) for my y-axis. I need a little assistance on creating this memo.
I've been ...
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Selecting an amplifier - a PA or LNA that seem to have similar gains and P1db
I am using an SDR that outputs a maximum power of -25dBm. I need about 15dBm to go into the Tx antenna.
I am looking at a PA and an LNA that have similar P1db points, but the LNA has a much better ...
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How is the Tx/Rx Gain calculated in USRP?
I'm using Software Defined Radio NI USRP 2922 (Universal Software Radio Peripheral). I know that USRPs are uncalibrated devices. In many exampls you can set the so called Tx or Rx gain (as in the ...
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GNSS antenna properties
GPS has three seperate frequency bands which are L1, L2 and L5 while Glonass has two seperate frequency bands including L1 and L2. Also Galileo has three frequency bands named as E1, E6 and E5.
I ...
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413
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Homemade GPS Receiver: Cascading LNAs and Band-Pass Filters?
Over the last couple of months, I developed a software-defined GPS receiver. Unfortunately, it's not very sensitive, and can only detect very strong satellite signals. For the RF front-end, I am using ...
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FT2232HL - using FIFO to send continous data to processing + signaling information
I'm designing a Software Defined Radio project.
I want to use an FPGA, DAC, ADC and FT2232HL bridge to handle communication with PC.
Can I stream continously data from PC to FIFO?
If I will use a FIFO ...
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Send a file over SPI by FT2232HL [closed]
I want to send a bitstream into an fpga with FT2232HL chip. How should i implement sending a file in C to FT2232?
I think about continous transmitting of file, instead of sending it in chunks
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Troubleshooting NOAA double cross antenna
I've been trying to recive NOAA automatic picture transmission (APT) pictures for a year now.
I never got a picture with V-dipole, so I decided to build a double cross antenna. I used 75 ohm coax ...
