5

Wow, I'm honored by Matt L. doing what I'm often doing: Referring people to GNU Radio. The project actually has a list of recommended literature, but I don't know how well that'd fit you. It's probably still worth looking into. Then, regarding QPSK: Well, it's one of the basic constellations, and you'd probably be best off reading a textbook intro to ...


5

Three reasons to increasing the sampling rate further are 1) To relax the requirements of the post D/A conversion filtering for image rejection. 2) Increase signal SNR by spreading quantization noise for a fixed number of DAC bits across a wider frequency range. 3) Minimize passband droop in the D/A reconstruction. Reason 1 is the most dominant one in my ...


4

First and foremost, I would recommend against over the air testing for this given the significant challenge in really being able to provide the same signal to each radio (since you have both temporal and spatial constraints that you cannot simultaneously meet). I would instead use one GNU radio as a transmitter (or any other repeatable high quality source) ...


2

It will work when you take the 2nd gradient of the signals: import numpy as np from scipy import signal s0 = np.gradient(np.gradient(s0)) s1 = np.gradient(np.gradient(s1)) np.argmax(signal.correlate(s0, s1)) -> 525358 That corresponds to a shift of 1071 which is close to your expected 1069 Interestingly the minimum (most negative correlation) is close ...


2

The high-frequency (RF) section of an SDR is all analog. Typically, the analog receiver downconverts the RF signal to an intermediate frequency that is within the Nyquist range of the ADC. As Stanley points out, you can also do bandpass sampling, though that is less common, in my experience.


1

When working with such an RF signal, numerically transformed to a stochastic timeseries, to which extent can I consider the signal to be stationary? That depends on your signal model. We can't tell you that – but for example, in time-slotted system, obviously the received signal can't be stationary – its variance (which is basically its power) depends on ...


1

For those given specs, without additional hardware (upconverters) or modifications to the SDR circuit, it's not possible to detect AM or FM (88-108 MHz) range of frequencies. As you might have also seen, there are frequency range extenders (especially on the low frequency range) available as kits. Also, the sampling rate determines the maximum bandwidth of ...


1

this is John BG 1.- GFSK is not same as single tone According to the CC1101 specs you refer to, the C1101 uses GFSK. GFSK varies the varrier frequency, therefore the spectrum cannot be a delta. Call it a 'shifting delta' but it cannot be same spectrum as just a tone. 2.- you want the carrier frequency to vary ISM are crowded bands, the carrier has ...


1

Let's start from the beginning. Given a real signal to a quadrature circuit, two components are generated, I, the real component, and Q, the imaginary component, which is the same as I, only it has a 90º phase shift. So, we have I and Q, which are the same signal but 90º shifted from each other. I understand this, it's simple. What you are talking about is ...


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