Questions tagged [software-defined-radio]
The software-defined-radio tag has no usage guidance.
83
questions with no upvoted or accepted answers
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Efficient frequency domain search for reduced number of hypotheses
In CDMA signals (such as GNSS) there are two unknown parameters when one receives the signal, residual carrier frequency and an unknown delay. Assuming the carrier frequency residual is known, what is ...
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Having trouble transmitting/receiving a BPSK signal using two USRPs
I am relatively new to working with SDRs and GNURadio and I am attempting to generate a BPSK signal and transmit it through one USRP and receive and demodulate it on another USRP. I am using GNURadio ...
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59
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Smoothing Filter on Signal
With python scipy I am processing (in real time) chunks of 250,000 each a CW pulsed beep radio signal in python from a RTLSDR. The signal after some basic processing and decimation is 9995 samples ...
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2
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Triangulation by phase delay basic requirements
I'm trying to identify the relevant specifications/calculations for building a system (at least theoretically) to accurately triangulate the position of a 915MHz CW transmitter to within 1cm. I have ...
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What is the line encoding in this FSK signal
As a learning exercise, I'm trying to reverse engineer the radio protocol of a 27MHz wireless mouse. The device currently transmits on the 27.045MHz channel and uses 2FSK. I have an IQ recording of ...
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Why is channel estimation done after synchronization and why does it work?
I am interested in Software Defined Radio communications where almost all processing is pushed to the digital domain.
I'm wondering why is channel estimation done after frequency and phase ...
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104
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Does anyone recognize this modulation?
I'm trying to extract the code of my garage remote, but i have some difficulty to find witch modulation has been used.
At first I thought it was a simple digital modulation, but there is some strange ...
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657
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IQ imbalance on quadrature signal
Hi I am attempting to develop a reasonable IQ balance mechanism for a quadrature signal coming from a software defined radio.I can balance out the amplitude and phase differences at one frequency ...
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I want to transmit a CW signal using SDR could be pluto or hackrf but I haven't used any one of them can anyone help me
I am using HackRF or Pluto SDR for transmission of a CW signal, after reading the documentation of the HackRF one SDR I found out that it transmits data in only 8-bit signed quadrature samples. Now I ...
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108
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QPSK Receiver: Blind coarse frequency offset esimation issue
In this single carrier QPSK receiver, is designed to receive QPSK data from a satellite in Low Earth Orbit. Since the satellite speed in this orbit is around 3000 m/s and our carrier frequency is 12 ...
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How to effectively resolve bitstream from an array of signal amplitude
The other day, I asked about how to model a receiver from 1090MHz ADS-B and Mode S signal, link to the post. With the support from Mbaz. I thought that it was not accurate that if I used a Zero-IF ...
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USRP N210 B & F Lights
During setup of a USRP N210 on MATLAB's Communications Toolbox Support Package for USRP Radio, the initial test failed on "Receive the signal and verify the frequency of the tone" field. ...
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Complex samples in OFDM signal, after fft-block at the receiver, have rotating amplitude towards zero even after phase correction
First of all, please consider my lack of experience/background in real time transmission using SDR especially if my explanation was expressed technically well.enter image description here
I have ...
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OFDM complex symbols have dynamic phase shift after the fft-block & before the BPSK demodulator at the receiver ,
I have transmitted and received an OFDM-signal using the same ADALM-Pluto-SDR's Tx/Rx Antenna.
I have used BPSK baseband modulation with symbol freq=312.5 KHz, L (length of ifft)=64, fsampling=fsym*L=...
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Why is bandwidth inversely proportional to mulitpath interference?
I have a project related to Signals of Opportunity and during my research on the communication signals that can be used for navigation purpose I saw that as references are given below signals that ...
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DSP library for Software Defined Radio
Can anyone recommend a good C library for SDR? To be more specific I just need a function in C to compute coefficients for CIC compensation filter (I need to do it in real time, so Matlab is not an ...
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numerical time differentiation in GNURadio
I'm hoping to put together a cheap modulation monitor for wideband FM radio using an rtl sdr usb, on the FCC website, it's listed that the modulation percentage for an FM station is the actual ...
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CIR calculation from SDR data: RTL-SDR, bladeRF
We’re developing a prototype using bladeRF and various Python scripts for processing IQ samples.
The system works mainly around 2.4 GHz frequencies: Wi-Fi and Bluetooth.
One of the needed functions is ...
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SDR : IQ GMSK signal demodulation
I'm trying to develop an application for the demodulation of some GMSK signals transmitted over the air.
I'm using a RTL-SDR which outputs 8 bits IQ samples of the baseband signal.
Here is what I've ...
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840
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Gnu Radio Constellation Receiver
I am trying to use gnu radio to transmit data from one SDR to another using a 16QAM modulation scheme. This is the diagram on the receiver side.
Looking at the constellation sink, the constellation ...
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Interference between two signals with the same frequency. (exercise from the book software receiver design)
I find it hard to describe the LPF. This is an exercise from the book Software Receiver Design
Build Your Own Digital Communications System in Five Easy Steps chapter 4.23.
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347
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RF direct conversion down to DC and signal recovery from IQ
I've previously worked with super-heterodyne receivers where the IF spectral content has been above DC.
Reading the below tutorial; direct down conversion receivers are used to mix a signal of ...
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703
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RSP1A sample rate vs if bandwidth
I'm using the RSP1A SDR and I want to understand how to choose the best configuration for receiving a signal of 125 khz bandwidth.
I would like to know if when choosing the option 200 KHz IF ...
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Help in identifying low speed image transmission protocol over RF
In the seventies I worked for Muirhead on press fax machines that used to transmit pictures over radio and landline as I recall two FM systems were used a carrier 800 Hz modulated +- 150 Hz and 1900Hz ...
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Software Defined Radio samples analysis using gnuradio and python
I'm trying to replicate what gnuradio is doing in "pure" python with a hackrf. Having mixed result, I decided to use the same data to compare the outputs I obtain. My gnuradio workflow is the ...
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Signal view from two different receivers (of the same model)
I have two SDRs hooked up to two different computers, both radios tuned to the same frequency. They sample at 2Msps. What I would like to do is start up both (at 'about the same time'), and, after ...
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Considerations when determining squelch
I asked this question recently. From the comments I learned that squelch is not a hard and fast thing, and that many considerations might go into determining a reasonable value, depending on use, the ...
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791
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Moving signal power normalization
I am using matched filters using GNU Radio to extract from noise a CW Morse signal. The filter actually performs pretty well in various SNR environments. My problem is that the threshold upon I decide ...
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511
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Short VHF pulse detection from SDR
I need to detect a short (10ms) VHF pulse that occurs every 1.5s at a specific frequency (e.g., 150.20 MHz).
I have an SDR that support IQ sample rates up to 10MSPS but due to computing constraints 2....
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Detect FSK high/low bits in presence of noise with only simple processing
I'm currently in the process of writing DSP code, based on the amazing RTLSDR project, and using this as a vehicle to teach myself the basics of DSP (I have an extensive background in software ...
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343
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Modulating ofdm in audio spectrum
Trying to modulate audio with OFDM data.
My fs = 44.1khz, i'm using 64 sub-carriers, but i'm only using 5 sub-carriers for data, so my bandwidth is about 3.445khz. I'm not sure how to properly write ...
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How to correctly visualize GFSK traffic in GNU Radio
I acquired some GFSK traffic from 2.4 GHz with HackRF at 20 MSPS. I want to visualize the raw bits after quadrature demod (as shown here). Only visualize, I don't need exact decoding. However, the ...
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Implementing an SDR using C++
coming from an embedded background, i'm not that familiar with DSP/SDR and there's project i'm working on, i have been working with gnuradio and things are working fine, now i'm looking for a try to ...
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Is it possible to cheaply convert analog to digital at the gigahertz sampling rate?
Consumer software-defined radio devices have become much cheaper and offer sample rates in the tens of million samples per second, but that still seems too low to parse WiFi or ethernet in-software.
...
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Demodulate SDPSK in GNU Radio for Orbcomm satellites
I am working on my bachelor thesis, of which you can read the assignment below:
Implementing a Demodulator and Decoder for Orbcomm satellite signals using opensource software
Satellites in Low Earth ...
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1
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Min. sample duration for FFT of low frequent signals obtained from zeroIF receiver
I am new here and a beginner with SDR & FFT.
For antenna pattern measurements, a flying probe antenna is to be used to sample the electromagnetic near-field in front of an antenna. A lightweight ...
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TRANSMIT 16QAM 5MHz Signal Via NI USRP 2900
I am trying to generate 5MHz signal. I am using NI USRP with matlab. I have extended the existing MATLAB QPSK Tx Rx to 16QAM, Now i am struggling with advacing the testbed to send and receive 5MHz ...
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2
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Transmitting data with QPSK using an SDR
My question assumes that I want to transmit some data using QPSK using and SDR.
The SDR will be fed with IQ data and this will transmitted at a sample rate Fs and be up converted to a carrier ...
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USRP N210 Connection Issues on Ubuntu 22.04 VirtualBox VM
I am running into consistent connection issues when trying to run a USRP N210 on a VirtualBox Ubuntu 22.04 VM. I built uhd from source on the ettus page, configured a static IP address in Ubuntu, ...
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is it relevent to plot the parcimony of a signal in function of its SDR?
Whilst trying to compare the performance of three blind source separation methods, is it relevent to plot the parcimony of a signal in function of its SDR?
Thank you...
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How to determine the size of DFT bins to implement a bandpass filter with FFTW on SDR
I'm implementing a bandpass filter to isolate the amplitude of a UHF FM signal with a 12.5Khz bandwidth. I'm having difficulty isolating the correct bins and bin spacing, given my DFT to isolate the ...
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Which type of modulation is used in this RF Signal?
I am working on reverse-engineering a few devices, I got some using ASK and FSK but I could not grasp this other one. I am attaching some photos from its captured signal took from URH (Universal Radio ...
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FFT on SDR FM Radio Signal
I recorded a simple FM signal using my SDR (centered at 100.3e6 hz and sample rate of 2.048e6 per second). Without any transformation, I ran an FFT on the signal and it showed a signal with some width ...
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SDR lose samples at high bandwidth (sample rate)
When receiving bandwidth (sample rate) is small (<~28 MHz), the signals are received without any distortion. When I choose high bandwidth (for example 40 MHz), sometimes the signals become ...
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Biphase/Manchester floating-point decoder based on matched filter
I need to perform soft Viterbi decoding on a Manchester-encoded BPSK/QPSK signals. To that end, I need a floating point Manchester decoder. Most of the implementations I have seen operate on hard bits....
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SDR - Manual FFT PSD vs pylab PSD
I am trying to calculate the power spectral density step by step using numpy FFT and comparing it to the PSD calculated by pylab PSD. Difference b/w plots of both methods can be visualized from in ...
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Interference between 121.5Mhz and 124.5Mhz
I'm new to Software Defined Radios and trying to find out if powerful signals are a cause of my own interference, a poor setup, or just a lot of traffic. I'm using a HackRF One with an ANT500 antenna.
...
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Research on SDR security Gnu Radio and legal transmission with filters
In fact, I am doing research around SDR and possible dangers. Then I stumbled upon the most well known "replay attack". Via Black hills, I came across the following diagram in gnuradio:
The ...
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49
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SDRs synchronization
I have 3 software defined radios (we can suppose that we have Ettus X310). I need to synchronize them because I need a high level of accuracy.
I know that I can use the Octoclock to synchronize them, ...
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702
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More Efficient Frequency Shift + FIR Decimation
I am dealing with complex IQ data from a software defined radio. I'd like to digitally shift the spectrum by some amount to center an off-center signal, then decimate down to that signal only. ...
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