Skip to main content

Questions tagged [software-defined-radio]

Filter by
Sorted by
Tagged with
0 votes
0 answers
18 views

GMSK Modulator Large sample Buffer size and high Bandwidth

I found good answers to my queries here Gaussian Pulse shaping filter and suggestion for NCO based GMSK modulator seems to be undersstandable. Thanks to Dan Boschen , but when moving ahead to design ...
user3696623's user avatar
0 votes
0 answers
25 views

How can I ensure that I am transmitting at a certain baud rate using GNURadio, PlutoSDR, and GMSK modulation? What is the relation to samples/symbol?

I am new to signal processing, so this post may not be properly phrased, but I am attempting to use GNUradio to send a GMSK-modulated string to a CubeSat that my club is ground testing. The satellite ...
jtn050's user avatar
  • 1
0 votes
0 answers
21 views

BERT (bit error rate test with ADC )

I'm trying to make a digital decoder. I sample a digitally modulated signal with the LTC2387, an 18-bit 15MHz SAR ADC. The carrier signal is at 2.1MHz, and is digitally mixed down to DC to obtain the ...
Abdel Djaferbey's user avatar
0 votes
0 answers
49 views

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. ...
Zaz's user avatar
  • 101
0 votes
0 answers
17 views

Synchronization TX and RX pulses in Pluto-SDR

I am currently working on implementing a FMCW radar for SAR application, I have successfully generated, transmitted, received the CWchrip. But when I move to the calculation of the beat frequency by ...
Raj Patil's user avatar
2 votes
1 answer
104 views

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 ...
Al Grant's user avatar
  • 131
0 votes
1 answer
39 views

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 ...
Tom944's user avatar
  • 1
0 votes
0 answers
27 views

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 ...
Muhammad Danyal Khattak's user avatar
1 vote
1 answer
53 views

What is the standard data format for transferring IQ data between interfaces?

I've seen IQ data typically combined within a single 32 bit word when sending streams of data between different components. (i.e. I & Q are both signed fixed point integers with 16 bit word length ...
Aaron Hoover's user avatar
1 vote
0 answers
64 views

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 ...
Raj Patil's user avatar
1 vote
0 answers
122 views

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 ...
Jacob's user avatar
  • 121
1 vote
0 answers
36 views

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 ...
Tuấn Nguyễn Anh's user avatar
2 votes
1 answer
89 views

Modeling 1090MHz receiver for aviation transponder

I'm building a Mode S and ADS-B receiver for TDOA calculation. I am planning to use an SDR with Zero IF to receive the downlink 1090MHz replies from aviation transponders. Currently, I am modeling the ...
Tuấn Nguyễn Anh's user avatar
2 votes
0 answers
50 views

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 ...
turdfergason's user avatar
1 vote
2 answers
77 views

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 ...
Koisto's user avatar
  • 11
1 vote
0 answers
28 views

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. ...
Austin Seward's user avatar
0 votes
0 answers
61 views

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, ...
Austin Seward's user avatar
1 vote
1 answer
108 views

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 ...
Walkürie's user avatar
1 vote
0 answers
96 views

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=...
Walkürie's user avatar
1 vote
0 answers
75 views

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 ...
Furkan ÇELİK's user avatar
1 vote
0 answers
54 views

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 ...
dcs's user avatar
  • 45
1 vote
1 answer
105 views

Replicating SDR transmitter and receiver (shifting of a quadrature signal)

I am trying to implement an SDR transmitter and receiver based on the description here. ...
Ladislav Ondris's user avatar
2 votes
1 answer
875 views

Can you please help me in generating a chirp signal in GNU radio by creating a module of your own?

I am currently working on a FMCW radar using a SDR I have done the simulations in python and am moving towards simulations on GNU radio. In python it was easy to generate a chirp, just use the scipy....
Raj Patil's user avatar
0 votes
1 answer
61 views

Does SDR configured with low sample rate automatically averages samples?

This is probably a basic question but I didn't find any answer online. Suppose we configure a SDR (least say, with a maximum sample rate of 100 Msamples/s) with a low sample rate (e.g. 1 Msample/s). ...
mabeco's user avatar
  • 13
0 votes
0 answers
7 views

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...
BLOBA fitz's user avatar
0 votes
1 answer
559 views

TX RX text via gnuradio using hack rf

I have a problem here - either I'm stupid or my hack rf is broken I am trying to send text via 2 hackrf like in this tutorialusing GMSK The simulation returns the text is correct, but when I run the ...
Nortan's user avatar
  • 3
0 votes
0 answers
145 views

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 ...
Jefferson Henrique C. Soares's user avatar
0 votes
0 answers
201 views

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 ...
ALEX's user avatar
  • 3
0 votes
1 answer
1k views

Spectrum analyzer resolution bandwidth (RBW) for LTE signals

I am trying to measure the maximum output power of an SDR transmitting a 20 MHz LTE signal with a spectrum analyzer. Adjusting the resolution bandwidth (RBW) changes the power spectral density (PSD) ...
Antonio Albanese's user avatar
0 votes
1 answer
178 views

Why don't we need frequency and phase correction in AM and FM?

As far as I understand, double sideband AM with carrier and FM can be demodulated via SDR (Software Defined Radio) without frequency or phase correction. For AM, received signal is $$r(t) = A(t)\cos(\...
unique's user avatar
  • 123
1 vote
1 answer
171 views

Generating I Q samlpes for particular sample rate

I want to know what the sample rate of I and Q samples generated for transmission, in the function below from https://github.com/lyusupov/ADSB-Out/blob/master/ADSB_Encoder.py samples are generated ...
Mas's user avatar
  • 11
1 vote
0 answers
183 views

Amplitude modulation in SDR [closed]

I understand the theory of amplitude modulation. However, I couldn't understand it's implementation in SDR, which use IQ data, and I would like to learn end to end amplitude modulation system in ...
unique's user avatar
  • 123
1 vote
1 answer
71 views

Is the phase of a IQ point related to the local oscillator frequency?

When considering a direct conversion SDR receiving or emitting architecture, we can "represent" the received or transmitted signal as the sum of two components, the I and Q component. Each ...
Rêve's user avatar
  • 25
2 votes
1 answer
135 views

Choosing the scaling parameters for a modem implementation

I have succesfully modeled a modem using floating-point data and with the following scheme, where the SRRC filter has gain G=6dB. ...
squeakyclean's user avatar
0 votes
2 answers
106 views

How to achieve a DC portable power source with low noise in 400 MHz frequencies

I am working on an SDR composed system that is plugged into a Raspberry Pi board powered by a 5V DC Power bank. The SDR is configured to measure a signal around 400 MHz. The noise floor measured by ...
M.FAKHFAKH's user avatar
1 vote
0 answers
207 views

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 ...
Jacob's user avatar
  • 11
1 vote
0 answers
66 views

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 ...
Oleg's user avatar
  • 11
0 votes
0 answers
128 views

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....
Moses Browne Mwakyanjala's user avatar
0 votes
0 answers
210 views

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 ...
Abdul wahab's user avatar
0 votes
1 answer
187 views

oQPSK symbol synchronization

I'm validating a C++ oQPSK receiver. The 5Mbps oQPSK signal is generated by a satellite emulator. The receiver structure goes as follows: SDR --> AGC --> Costa's Loop --> Delay --> ...
Moses Browne Mwakyanjala's user avatar
1 vote
1 answer
1k views

How to demodulate FM I/Q output from SDR#

Using SDR#, I saved the baseband I+jQ signal centered about a commercial FM station to a *.wav file. I want to write python code to demodulate this signal. I know that SDR# can read in that file and ...
Nick Elias's user avatar
2 votes
1 answer
279 views

USRP N310 RX gain lower than other SDR with same GNURadio script

In my company, we are using a GNURadio script with a PlutoSDR to receive packets coming from a transmitter located very far away. The receive power is really weak, our antenna is receiving something ...
Amaury's user avatar
  • 21
-1 votes
1 answer
62 views

gnuradio , SDR usrpx300

I use usrp x300 SDR. I'm confused about Bandwidth and sample_rate. How do I calculate them? is ...
Rami Mrzk's user avatar
0 votes
0 answers
77 views

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. ...
Baa's user avatar
  • 101
3 votes
1 answer
79 views

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 ...
ban09's user avatar
  • 31
2 votes
2 answers
2k views

How does the sample rate work on an SDR?

How can an SDR, which has a sample rate of about 32MHz record signals with a frequency of 1GHz? Shouldn't the sample rate be at least two times as high as the frequency or am i missing something?
fsdjfh's user avatar
  • 21
0 votes
0 answers
71 views

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 ...
HereToLearn's user avatar
0 votes
1 answer
56 views

Why aren't I getting my expected FM channel when multiplying these two frequencies?

Hope y'all are doing well. Recently I've picked up a LimeSDR and interfacing it with GNURadio and been having a blast with it. I got my first FM receiever demo working using examples from LimeSDR FM ...
Pllsz's user avatar
  • 139
1 vote
2 answers
715 views

G3RUH Multiplicative scrambler in C++

I have written and tested a G3RUH (1 + X^12 + X^17) descrambler. It seems to work quite well in an SDR project I'm working on. I'm currently working on a scrambler and I can't get it to work. Below is ...
Moses Browne Mwakyanjala's user avatar
2 votes
1 answer
549 views

Sampling rate for a 200 kHz signal

I'm using a rsp1 to sample the output of an underwater acoustic transducer which has a resonant frequency of 200 kHz (with a 500 Hz bandwidth) . The transmitted signal is a CW pulse which can vary ...
Brett's user avatar
  • 21

1
2 3 4 5