Questions tagged [modulation]
Modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with the amplitude of low-frequence modulating signal which typically contains information to be transmitted.
657 questions
0 votes
1 answer
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16-QAM high noise? GNU Radio
I've been learning a bit about DSP recently and tried to build a working 16-QAM (or M-QAM) modem in GNU Radio, but haven't been successful. I think the issue might be high noise caused by some of the ...
1 vote
1 answer
123 views
Envelope extraction & Hilbert transform conditions
Question: Is it possible to demodulate perfectly an AM envelope from AM-FM signals? I have found 2 contradicting explanations Answer 1 - NO: Following this thread: Why Hilbert Transform is terrible ...
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1 answer
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How to compute SNR after splitting an RF channel into I and Q channels using a Mixer?
If I have a AWGN real channel given by : $$r_{RF}(t) = Acos(2\pi f_ct + \phi) + \eta(t)$$ Suppose, $\eta(t)$ is a WSS WGN process with 0 mean and $R_{\eta\eta}(\tau) = \sigma^2\delta(\tau)$ and $S_\...
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Mutual Information and Data Rate
Mutual information in Theory Communication context quantifies the amount of information sucessfully transmitted over the channel or the the amount of information we obtain given an observed prior ...
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0 answers
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BER BPSK in GNU Radio
My goal is to calculate the BER and compare the BER curve with theoretical result from this E2E BPSK system. Hence, my idea is to save the bit stream of input and bit stream of output to calculate the ...
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2 votes
1 answer
65 views
Neural Network Encoder and Traditional Modulation
Does anybody understand how actually the neural network encoder works? The NN encoder replaces the physical modulation block. In a physical modulation block, the codeword is mapped to symbols, which ...
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0 votes
1 answer
90 views
SNR Calculation from Channel Estimation
I wanted to ask how can we calculate SNR on the basis of channel estimation using Pilot Symbols and make CQI table for Adaptive modulation coding according to the estiamted SNR values.
1 vote
0 answers
65 views
Radar Detection Threshold with Stochastic Echo Energy
I'm currently simulating radar target detection using Linear Frequency Modulation (LFM) signals, and I have a few questions regarding the detection process in the presence of a stochastically ...
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