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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Synchronization and downsampling after matched filtering - GNURadio polyphase clock sync

I am trying to model a QPSK transmission. For this, I am using the software GnuRadio and more specifically the block polyphase clock sync. This block performs timing synchronization for PAM signals by ...
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GNU Radio | Transceiver loopback adapted | Transmission stops unexpectedly

(This is a follow up question to a previous question: link) I have implemented a flowgraph of a transceiver loopback inspired by the examples found at ...
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Carrier recovery with the Costas loop : PLL pull-in range

I have created a channel model in GNU Radio (a modified version of the default GNU Radio Channel Block). Its performance under AWGN (without timing, phase or frequency offsets) aligns properly with ...
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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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GnuRadio's SNR estimators usage

I'm trying to calculate the SNR of a satellite signal using GRC, but all of the 4 offered estimators either have a lot of -NaN values or are ~35dB throughout the entire recording. (I just connected ...
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Dynamic loop bandwidth for a Costas loop

I'm using a Costas loop for carrier recovery. The BER vs SNR (from GNU Radio Simulation) curve for different loop bandwidths (0.03,0.05 and 0.07) is shown in the graph below. It can be seen that the ...
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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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Phase difference calculation for non divisible sample rate to frequency

I am learning DSP and I am trying to simulate a simple phase difference calculator between two sinusoidal signals using GNU radio. My flowchart looks like this: As can be seen on the chart, one of ...
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Residual carrier tracking with PLL

Residual carrier systems such as PCM/PM/NRZ and PCM/PM/Bi-phase are common in space applications. Compared to suppressed-carrier systems such as BPSK, the literature sources on residual-carrier ...
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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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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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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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2FSK implementation with VCO GNURadio

I am fairly new to GNURadio. I am trying to generate a 2FSK with minimum frequency shift. Instead of multiplying with a 8MHz complex carrier, I directly use VCO to generate two frequencies. One at 7....
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What is the successor to the GNURadio liveCD?

I used to burn and run the GNU Radio livecd - it was a very nice package that gave me a working gnuradio environment - with drivers and tools - without doing a lot of sysadmin or package management, ...
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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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Increasing samples per symbol degrades correlation between signals

I am trying to implement a simple pseudo-noise (PN) ranging simulation. I have used this GNU Radio example, and I have adapted it a bit to suit my needs. Here is a screenshot of my flowchart: The ...
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GNU Radio - Bandwidth and Band Reject Filter

I am currently trying to generate a psk modulated carrier with gnu radio. Attach is an image of my flow graph. As can be seen I am generating a bit stream using the Random Source module and ...
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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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How to setup filters to catch 4FSK deviations

I'm trying to demodulate a radio signal from Motorol DP4801 (MOTOTRBO) that follows DMR specification. I'm receiving the signal by using HackRF with the rate sample 1 MHz. The radio uses frequency ...
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GNU Radio | Grouping just 24 consecutive soft bits from a repeating tagged stream onto 3 bytes, starting from a specified tag

A vector source [0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,1,1,1,1,1] produces repeatedly a tagged stream with one tag, ...
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GnuRadio FM Receiver: Heterodyne vs Xlating vs Direct

I'm trying to build an FM receiver (and eventually transmitter) in GnuRadio that will be able to interact with my local repeater. Starting with WBFM (because I can consistently pull in broadcast ...
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EbNo, SNR, and BER simulation for BPSK with convolutional code

Im currently simulating BER performance of CCSDS convolutional code. Im having some troubles in specifying EbNo and SNR in gnuradio blocks. From matlab webpages on BER simulation for RRC pulse and ...
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Phase noise modeling using gnuradio IIR filter

I need some advice regarding phase noise modeling using gnuradio IIR filter. I'm trying to synthesize phase noise (multiplicative) with a given noise mask. In one paper, the authors were able to ...
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Band-edge filtering for an RRC pulse-shaped manchester/biphase-encoded bitstream

Band-edge (derivative matched) filters can be used to generate an error signal for frequency locked loops (real part) or symbol timing loops (imaginary part). The derivation of the band-edge filters ...
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Blind equalization with constant modulus algorithm in GNU Radio

I'm currently simulating the effect of multitap channel on BPSK as well as its remedy i.e. equalization. The modem is expected to work with satellite TT&C transponder. The communication channel ...
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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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USRP + GNU Radio as 1 GHz bandwidth spectrum analyzer

I have maybe not trivial but some interesting question. I need to create 802.11ac channels spectrum analyzer with USRP. Hardware: USRP B210 Software: GNU Radio 3.7.9 PC: Intel Core i3 i3210m 16 GB ...
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GNURadio Sending Short Packets

I'm trying to create a basic GNURadio flow graph that will transmit a short message in order to receive an appropriate reply back. I currently have the following flowgraph: I have a program that ...
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Unable to stabilize 8-PSK signal with self designed costas loop

I am trying to make a signal processing block which implements the costas loop to stabilize an 8-PSK signal. Here is the flowgraph with "costas_loop" being my block. My workflow is the following - <...
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How can I perform timing recovery from the envelope of PSK signals?

I'm trying to reimplement FDMDV in GNU Radio, largely for educational purposes. It consists of 15 PSK subcarriers, 75 Hz apart, 50 symbols/sec each. The center one is BPSK and alternates phase each ...
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Time recovery - GNU Radio

I read about Time recovery (as an example, the Mueller&Muller algorithm); it is linked to when you should sample your signal. I am currently working on a project with GNU Radio and there is ...
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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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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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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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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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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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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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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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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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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 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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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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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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