Questions tagged [gnuradio]

GNU Radio is a free software development toolkit that provides the signal processing runtime and processing blocks to implement software radios.

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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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Why should costas loop be done after clock recovery, as opposed to before?

In GNURadio's PSK tutorial they place the costas loop after clock sync and linear equalizer. This seems odd to me. I'm thinking that it's easier to lock onto a carrier frequency at the higher RF ...
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GNURadio 3.8 QPSK : Hard time to recover the right symbols/data

Cheers, I am demodulating a QPSK signal on GNURadio, the data transmitted is a known HEX file with the "1ACFFC1D" foreword every 124 bytes, to check if the demodulation is a success, it ...
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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 ...
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Envelope of a series of pulsed signals [duplicate]

I need to record a series of pulse waves for an experiment. The recording is done via Software Defined Radio (GNU Radio). The pulse waves are modulated in such a way that the amplitudes of each single ...
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Frequency repartition and transformation in channelizer and synthesizer

I am trying to get my head around channelizers and synthesis filterbanks. I stumbled across this thread, with its attached paper. In the explanation of the synthesis filter bank, the following ...
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gnuradio: eCPRI link implementation for LTE

Need to build eCPRI link in xRAN network between eRE and eREC devices. In eRE I'm capturing via osmocom source (SDR device) and I have a stream of float32 complex IQ numbers as usual output. Now I am ...
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How to measure NB-IoT signal quality with GNU Radio?

I need to measure the quality of an NB-IoT signal. Is it possible to obtain RSRP, RSSI RSRQ or SINR using GNU Radio?
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What are these mysterious spike after the FIR filter?

The main paramter of this fir filter in flowgraph: Decimation:1 Cutoff freq:8KHz Transition width: 1KHz I have a very simple FIR test in Gnuradio ,the flowgraph is below: When I change the signal ...
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Problem to extract value from complex_to_mag_squared GNURadio block

I am trying to dissecate a large bandwidth into smaller ones and, for each of those smaller bands, see if it contains enough energy to consider that a message is sent in it. To do so, I am thinking of ...
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How to downconvert NB-IoT signal using GNU Radio

I have captured an NB-IoT signal to a file (I-Q samples) using GNU Radio. The signal is centered at 768.2 MHZ and has a bandwidth of 200KHz. I need to downconvert the frequency to 767.8 MHz also using ...
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What cause amplitude changed after `multiply`?

In Gnuradio,multiply 2 signals as below,max amplitude should be 1*2=2. Output shows the max amplitude beyond 2,around 2.4. What's the reason?
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How do I set GNU Radio Es/No?

I am trying to create a random signal in GNU Radio (using DVB-S2 specs for the physical layer) and transmit this signal using a USRP X310. This is shown below: Problem: I would like to be able to ...
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EVM reduction for GNU Radio GMSK quadrature demod using Wiener equalizer

I have been exploring different ways of improving the EVM performance of quadrature demod block for GMSK demodulation. As we all know, the Gaussian filter introduces intentional ISI, which can be ...
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time division duplexing (TDD) with USRP B2xx

I am going to implement a real-time TDD link (in the order of one-millisecond burst durations) using two laptops and two USRP B2xx (in either single antenna or dual-antenna ways). I searched a lot on ...
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How do I Correlation Estimate both for a pattern and its inverse in GNU Radio?

I'm using the Correlation Estimator block in GNU Radio before my Symbol Sync block, in order to more quickly and reliably clock the signal. My problem is that the data is sent as NRZ with ...
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Will USRP processing data be affected by time.sleep in PythonOOT?

I recently used usrpb210 + OFDM to transmit data again. OFDM uses gr-digital / examples / ofdm/ tx_ ofdm. grc,rx_ofdm.grc, I can receive data normally every time I transmit, and the number of packets ...
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GNU Radio and USRP audio source problem

I have a modem which accepts a voice in GNU Radio, digitizes and compresses it (codec2) and transmits it using USRP on one laptop and receives it on another laptop. When I use "Wave File Source&...
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GNURadio GFSK demod missing data

we are trying to develop a flowgraph for cubesat operation. Our flowgraph for includes both downlink and uplink parts in one flowgraph. It uses SoapySDR as a driver of an SDR. Most of the used blocks ...
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GNU Radio Low Pass Filter doesn't work as expected with different transition widths

I'm new to GNU Radio and signal processing. I don't know if the following is a simple question, but I have been scratching my head about it. I created a simple flow graph with a random source (0-3) ...
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Gnuradio running into audio underrun when using audio source and sink at the same time

I wanted to calculate the BER curve for an FSK audio modem transmitting via the speakers and receiving through the mic of the computer. I am using Aaron Scher's FSK loopback flowgraph The thing is, ...
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GNU RadioTagged Stream: How to clip the stream as "packet length" tag long

I am currently trying to develop a GNU Radio block which takes a tagged stream as an input. The tags keeps the length of the packets. But the distance between the tags and the packet length are not ...
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Undersampling in GNU Radio

I'd like to implement a FHSS receiver in GNU Radio, using a USRP B210. The total bandwidth of the signal is about 30 MHz, with each message having a bandwidth of about 200kHz. When I attempt to ...
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GNU Radio Vector output Receiving Error

I am implementing a GNU Radio block that takes an input signal as a stream and returns a vector stream. The code section is given below. The block is written to understand the mechanism (Therefore, it ...
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GNU Radio Stream Input-Vector Output

I successfully designed the transmitter block. I am now implementing the GNU Radio receiver block and using a Python (since it is easier for me to design a prototype) block that takes a stream of the ...
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GNU Radio, Frequency Hopping Spread Spectrum for High Hopping Intervals

I am planning to implement a frequency hopping spread spectrum transmitter and receiver in GNU Radio. In my project, the bandwidth of the message signal is around 200 kHz and the maximum frequency ...
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transmit signal with hackrf one

I want to use hackrf one to transmit a continuous signal. my question is that "can hackrf transmit signal continuously or it has certain interrupt between its transmission?" my question is ...
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Help understanding quadrature sampling and effective bandwidth

Let me start off by saying I'm at least a little embarrassed that there's something simple that I'm fundamentally not understanding here. Not sure if the blame is on me, or the prof that taught me DSP ...
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UBX could not transmit signal

I am new to x310. I want to transmit a signal with its UBX daughter board and using gnu USRP sink block . but it seems no signal transmitted. Is this a software problem or hardware?
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How to build a model for $2 \times 2$ MIMO using GNU Radio?

I have been trying to set up a GNU Radio flowgraph where I can implement a $2 \times 2$ MIMO system. don't know how to make spatial diversity using the blocks, also I am not sure which block ...
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Send real and complex signal from python to GNU radio. ZMQ Python SUB -> GNU Radio

I've been reading about this. To do this, you should use the ZMQ blocks instead of the UDP blocks because of data loss. Now when using ZMQ I have problems with the received signal, if I create a np ...
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Send complex signal and receive the same complex signal, GNU radio

I’m working on a project where I want to send complex symbols like 4-QAM, 8-QAM or 16-QAM for example and demodulate those symbols, the idea is to use the signals as points (like in the constellation ...
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Writing a BPSK Demodulator

As part of a larger project, I've been attempting to implement a demodulator for RDS, a digital transmission standard in FM broadcasting, in software with C++. I've easily been able to get as far as ...
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Frame synchronization for single carrier burst applications in fading channels

I recently started to implement communication systems with software-defined radios in GNU Radio. In my system design, I am planning to transmit data in burst mode, the frames will be not sequentially ...
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How to recover modulation symbols?

I am using GNURadio to send and receive a limited number of modulation symbols. I have constructed the following flow chart:random source(no repeat)->chuncks to symbols(file sink1)->polyphase ...
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GNURadio Guided Tutorial PSK Demodulation Example

I have been reading and doing the steps on this webpage of GNUradio : https://wiki.gnuradio.org/index.php/Guided_Tutorial_PSK_Demodulation In the middle of the page, there is a section: "Using ...
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Spectrum Smoothing

I recently stumbled upon this GNU Radio flow graph which smooths spectrum. Block parameters are seen in image attached below. Also visually results doesn't change if I take out "Keep 1 in N" ...
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Reed-Solomon error correction in GNU Radio

Can someone please explain how to define parameters for Reed-Solomon decoder correctly in GNU Radio? I have already looked at ETSI EN 300 744 Clause 4.3.2 , but it does not explain how to choose ...
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How to decode a binary Signal in a wav file into binary - sent here from stackoverflow

I'm doing a puzzle that gets me to call a phone number which produces a load of beeping sounds. Putting this into audacity as a spectrogram produces this: Zoomed in it looks like this: This looks ...
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Why the output data quantity of the channel model in gnuradio is less than its input data quantity?

I am facing a problem and I have created the following flow diagram to illustrate the problem. As shown in the figure, my input is 0,1+1i,2+2i,...,199+199i, I set the parameters of "channel ...
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Digital Selective Calling (DSC) Decoder in GNU Radio

I’m attempting to develop a GNU Radio FSK decoder for Digital Selective Calling on marine VHF but I seem to be stuck. I got my hands on a Standard Horizon handheld marine VHF unit with DSC capability ...
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How can I fix bad clock recovery for bursts with short distance?

I use GNURadio as a prototyping tool to build a receiver for a digital signal of a home appliance. The signal itself looks good so far. Also the symbol synchronization works well using the symbol ...
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Decimation with dynamic factor in GNU Radio

In a GRC flowgraph I have a custom OOT block which periodically sends a PMT message to the "command message port" of the "UHD: USRP Source Block" (for set the RF center frequency ...
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Implementing OQPSK in Gnu Radio Companion

I am currently trying to realize this block diagram in Gnu Radio Companion: Before using a file source block with the binary I want to send, I plan on just using a vector with an alternating 1,0 ...
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Relationship between sampling rate and bandwidth in gnu radio

I wondering something. While working with adalm pluto sdr in gnu radio, the sample rate I enter in the source block is actually bandwidth. I know that bandwidth must be half of the sampling rate ...
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To GNU Radio users - how you find a block class writing own python code using GNU Radio library?

How are you guys finding an interesting block class among available GNU Radio modules? I find it difficult to write own flowgraphs writing in python. Assume I want to use Constant Source block, I ...
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Chunks to symbols block, what is the use of 'dimension' parameter?

Can somebody explain me what is the use of 'dimension' parameter in Chunks to Symbols block in GNU Radio? As far as I understand it relates to dimensions in symbol table given as a first argument, am ...
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wireless card in place of an antenna/ hack a robot

My nephew has this toy robot and asked me to build a new remote for it. It's a "Cady Wida" robot from JJRC. When I opened it up, a tag inside said "40 MHz" and the board sported a &...
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AWGN noise variance in upsampled BPSK signal

When I simulate BER for basic PSK schemes, I set the IQ complex noise variance to $\sigma^{2} = \frac{E_{s}}{2*R_{m}*R_{c}}*\left( \frac{Eb}{No}\right)^{-1}$ where $E_{s}$ = Energy per modulated ...
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GNU Radio filter normalization

I have noticed that all filter taps from the firdes class are normalized by dividing them over the sum of all taps magnitude, as shown in the example below for Gaussian Filter. Is this normalization ...
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