Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [gmsk]

15 questions
6
votes
1 answer

Simplest All Digital GMSK Modulator

What is the simplest way to implement an all digital GMSK modulator with no multipliers? The implementation approach should be applicable to GMSK modulation with BT=0.5 or less (where intentional ISI is introduced to obtain higher spectral…
Dan Boschen
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From IQ signal to FM modulated carrier, how its done?

I am trying to comprehend GMSK modulation/demodulation. IQ samples are being phase keying is such a way that after multiplying them by complex carrier and sum both I and Q together, there is FM modulation. I don't understand how its being done. I…
Marcin Puchlik
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How to implement GMSK model by Thierry Turletti

I'm kind of new to signal processing and trying to implement a GMSK modulator using GMSK in a nutshell by Thierry Turletti to modulate a bunch of binary data and send them over RF antennas. I'm very confused about what is happening in this…
Johnny
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1 answer

Difference between MSK and GMSK?

I try to understand differencies between MSK and GMSK on transmitter side. Is GMSK the same than MSK except that a gaussian filter is applied on bits before modulating them? Is the half symbol delay on the Q path from MSK also done in GMSK? I was…
dsp_curious
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why GMSK use a gaussian filter instead of raised cosine filter?

I'm wondering why GMSK use a gaussian filter instead of raised cosine filter as a pulse shaping filter? Is there special reason?
agile
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GNU Radio GMSK modulator

I'm looking at the GNU Radio GMSK modulator block. The Gaussian taps are somehow convolved with a rectangular window with 4 * samples-per-symbol taps owing to the fact for GMSK, the filter spans four symbols. I was wondering if anyone could…
Moses Browne Mwakyanjala
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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 sends UDP messages to the UDP Source and receives the…
Noel Saldanha
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1 answer

difference between GMSK (Gaussian Minimum shift keying) and GFSK (Gaussain frequency shift keying)

I am unable to differentiate GMSK and GFSK. How do the modulation techniques differ in Tx? How do their receiving techniques differ..?
mano49j
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GMSK Big error in demodulation MatLAB Simulink

I am trying to do a PLC simulation system, but my problem is in GMSK demodulator, in my simulation in Simulink MatLAB my output signal is very different from the input signal, below the model: Below the block parameters: I start doing this…
user23447
0
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1 answer

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 pretty destructive at lower BTs values. I suppose a…
Moses Browne Mwakyanjala
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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 understood and what I've done : Since they are…
pior
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GMSK CFO estimation and timing recovery

My goal is to estimate the CFO and timing offset in GMSK modulated signal. I synthesize samples in Matlab and my goal is to add CFO and time offset to learn how to deal with mentioned distortions and successfully recover transmitted signal. I would…
Marcin Puchlik
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1 answer

Two-GSMK channels demodulation: 3dB difference in BER

I am trying to demodulate individually two GSMK channels separeted by 50kHz (one channel = 25kHz). I am working on a limited ressources hardware so I decided to make some optimization on the signal processing chain. Here is the architecture: after…
phaseer
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BER vs SNR simulation for GFSK modulation (Closed-form BER for GFSK)

I'm in the process of simulating the performance of a GFSK modem in GNU Radio. I have managed to get a curve similar to the curves I see in a number of literature sources. However, I need an accurate baseline that can show how accurate (or far of)…
Moses Browne Mwakyanjala
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0
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Confusion in GMSK Demodulation

I'm trying to implement this GMSK demodulator. Is the input to deviator in degrees? do I have to change it to radians? Does the output of the deviator has to be NRZ or Have to convert it to NRZ? I'm doing quadrature demodulation so I've to…
Sumbul
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