In signal processing, sampling is the reduction of a continuous signal to a discrete signal.
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39 views
Determining sampling rate in OFDM demodulation
I have seen that in OFDM, the sampling rate is much lesser than twice the bandwidth of signal. why is it so? How is sampling rate calculated in OFDM? Does it depend on the modulation type used inside ...
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1answer
46 views
Relation between CTFT and DTFT
I need to transform this function:
$$
x(t) = 4\sin(20\pi t ) - 5\cos(24\pi t ) + 3\sin(120\pi t )
$$
into a sequence $x(n)$ given that the sampling frequency should be 50 Hz. So that means the ...
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2answers
61 views
Ways to analyze electrical signals without FFT?
I am collecting a 15Hz sine wave at 1500Hz. Therefore, every 100 points of data collected should contain a single complete sine wave. If I sample for 10 seconds, I will have 15000 points of data. If ...
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1answer
62 views
How to measure the agreement between to curves?
I have values (plotted below) of expected RSSI values over time that I would like to compare with my measured RSSI values. What I was looking for was a way to quantify it so I can change parameters ...
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1answer
59 views
Dynamically changing cut-off and sampling frequency of a digital filter
I have designed a low pass filter that smooths the output coming from an accelerometer attached to a vibrating machine. I designed this assuming cut-off frequency $f_{c1}$, and sampling frequency ...
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71 views
BandPass Signal Vs PassBand Signal
Am reading Rick Lyons - Understanding DSP book about Sampling. I have few doubts related to this chapter.
what is the difference between Bandpass Signal and a Passband Signal ?
Can somebody give an ...
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40 views
Instantaneous Frequency variation
I am looking for a method to calculate the instantaneous pitch variation within a speech signal for time-warping application. Sample by sample frequency variation knowledge within a frame will give ...
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1answer
58 views
simulating multipath via tap delays in FPGA
I have a Xilinx FPGA running at 200MHz with an ADC and DAC on board. I am taking a 2462MHz sine wave (pretending it is 802.11b chan 11), mixing it down to 40MHz putting it through my FPGA, mixing it ...
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126 views
Adding echo to audio sample
I have recorded my own voice in Matlab and I intend to add some echo to it.I came up with one solution for getting the desired echo effect:
Delay the sampled audio in the time domain and adding it ...
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2answers
91 views
How to predict the spectrum of an aliased/folded signal without looking at the FFT?
This seems like a trivial concept but I just can't get the hold of it. I have a signal with two complex sinusoids having frequencies -25MHz and 17MHz. Currently it is being sampled at 64MHz so I get ...
2
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1answer
72 views
Converting frequency from Hz to radians-per-sample
In MATLAB I have to pass cut-off frequency for designing a filter. But this Cut-off frequency is in radians-per-sample. How do I convert my analog Cut off frequency in Hz, into the required ...
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37 views
How to calculate the quantum of the difference between two value of clock counter where the values are divided by 64?
I have a counter in my embedded system with f = 64 Mhz.
let's say its read value is $cnt_i$
where $i$ is the index of the time I sampled it.
$$\Delta = cnt_{i+1} ...
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94 views
How replicas are formed in Frequency domain when a signal is sampled in Time Domain?
I know that sampling in one domian [time or frequency] gives raise to replicas in another domain[frequency / time]. How replicas are formed. What is this Time domain periodicity and frequency domain ...
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1answer
53 views
pitch vs playback rate
Let's say I have an audio sample, whose pitch is known to be C4 (don't wanna go in detail here, let's say I just sampled a tuned piano playing the C4 key).
The rules of the game are: I can only ...
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0answers
55 views
Voice sample prediction scheme
I have some telephone voice audio with occasional "blips" in the audio. The blips appear to come from an IP link buried in the PSTN (this is a conceptual explanation, so don't worry about things like ...
