Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
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What is the bandwidth of a (real) sinusoidal tone, and pulse?
I would like to know how to go about calculating the bandwidth of:
A constant (real) sinusoidal tone
A (real) sinusoidal pulse.
The question is as simple as that, but I am having a hard time with ...
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Bounds of the derivative of a bounded band-limited function
Let $f(t)$ be a function with properties:
$$\begin{array}{ll}
t\in\mathbf{R}&t\text{ is in reals}\\
f(t)\in\mathbf{R}\text{ for all } t&f(t)\text{ is in reals}\\
|f(t)|<A\text{ for all }t&...
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Mathematical question that comes out of using bilinear transform
So this is related to the Cookbook and I tried solving it maybe two decades ago, gave up, and was reminded of the unsolved problem. But it's pretty damn straight forward, but I still got slogged down ...
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What is a $BT$ (Bandwidth-Time) product with reference to modulation?
I would like to know what does Bandwidth-Time product mean. I understand that Bandwidth ($B$) = 1/Symbol Time ($T$), hence $BT = 1$.
But how can it vary?
What is its significance?
e.g. When we say ...
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what is proper setting for Fb,Fc in Complex morlet wavelet (cmor)?
I am using Cmor-Fb-FC wavelet transform in matlab environment. Fb is bandwidth and Fc is center frequency parameters. with trail and error procedure I select Fb-Fc as 5-1, and I've got rational output....
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How are time resolution and signal bandwidth related?
I am confused by the dual concepts of time-resolution and bandwidth. Often I will hear that a pulse-compressed radar application 'doesnt have enough BW' for some specific time resolution that is ...
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What is the ideal FIR length, given a specific pulse length?
I am trying to ascertain what the 'ideal' FIR filter length should be, given the pulse length $T_p$ of a windowed sinusoid in noise that I seek to filter.
As parameters into an FIR filter that I ...
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Is there a condition for bandpass sampling?
Consider a signal that has lowest frequency component $F_l$ and highest frequency component $F_h$.
According to the theory of bandpass sampling, this signal can be sampled and succesfully recoverd if ...
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What is the bandwidth of product of two signals?
For signal $x(t)$ with bandwidth $B_x$ and signal $y(t)$ with bandwidth $B_y$, what will the bandwidth of the signal $z(t)=x(t)y(t)$ be?
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Interpolation of magnitude of discrete Fourier transform (DFT)
For example for peak frequency finding, it seems valid to use band-limited interpolation methods on the complex DFT bins, or separately on their real and imaginary parts and to calculate the ...
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Relating bandwidth and wavelength of a carrier
This came from a homework question, which I've solved. Just need some clarification.
I am asked to determine the bandwidth in a given amount of spectrum at a given wavelength. To find this, I know ...
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The necessity of null subcarrier in OFDM?
In looking to LTE specifications, with the subcarrier spacing $\Delta f = 15 \textrm{kHz}$,
for bandwidth $10 \textrm{MHz}$, fft size $N_{fft} = 1024$ that needs a sampling rate $F_s \geq 1024 \times ...
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Bandwidth of a signal using MATLAB
I need to find the bandwidth the signal $x = 50 \operatorname{sinc}(125(t-10))^2$.
(Where $\operatorname{sinc}(x)=\dfrac{\sin (\pi x)}{\pi x}$ [normalized] or $\operatorname{sinc}(x)=\dfrac{\sin x}{x}...
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Intersymbol interference due to limited channel bandwidth
What is the difference between limited-bandwidth induced intersymbol interference (ISI) and ISI due to multipath propagation.
I noticed that the delay spread in indoor environment is in the range of ...
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How to calculate bandwidth of a wire, "air" or other channels?
I'm really curious of how engineers identify what is the frequency range that could be sent through "wire" as channel? Do they put wire in front of them and make test that consists of sending ...
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How can I experimentally find the bandwidth of my PLL?
I recently designed a phase-locked loop. I would like to quantify its bandwidth so that I can better understand it.
However, I made this bandwidth in an informal manner due to my lack of formal ...
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Does "keying on" a sine wave at a zero-crossing reduce its bandwidth?
I understand that a pure sine wave of infinite duration occupies no bandwidth, i.e. it is only the modulation of a carrier that gives it sidebands. Does the exact timing of a sudden modulation make ...
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Detecting the original bandwidth of upsampled recordings
I have a set of recordings sampled at 16khz, but some of them are upsampled from 11khz and some from 8khz. Quite some of the recordings are noisy. What is the best way to classify the recordings ...
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Bounds of the difference of a bounded band-limited function
For a continuous signal (function), we have Bernstein inequality :
$$
|{df(t)}/dt| \le 2AB\pi
$$
where $A=\sup|f(t)|$ and $B$ is the bandwidth of $f(t)$. The question is: is there a relationship ...
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Multiband processing in one pass
I want to split signal in multiple bands and process each band. Number of bands is not yet determined, but it would be more then 6 and less then 11 (depending on the collected results)
As ...
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Correct way to add AWGN to a signal
I have a signal, S whose bandwidth is bw Hertz and is sampled at fs Hertz.
To contaminate it with a noise corresponding to SNR <...
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Bandwidth confusion
Let's imagine that I took a Fourier analysis of a random voice signal that I want to sample and plotted it's frequency components in frequency domain (frequency vs amplitude). Now I want to sample it. ...
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Uncertainty principle - Duration bandwidth principle
In one of NPTEL courses about time-frequency analysis, the professor said that the duration bandwidth principle is $\sigma_t^2 \sigma_\omega^2 \ge \frac{1}{4}$.
He added that the formula making use ...
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Value of power spectral density $N_0$ or effect of scaling bandwidth to SNR
I want to compare performance over AWGN channel of two systems that are exactly identical but their bandwidth. I will talk only about baseband system for sake of simplicity. For more details about ...
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How is the maximum theoretical data rate of a channel equal to $2B\log_2(V)$ bits/sec.?
According to Andrew S. Tanenbaum (in "Computer Networks", Chap. 2, Section 4 "The Maximum Data Rate of a Channel"), the Nyquist/sampling theorem states that "if an arbitrary ...
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How is it that a dial-up modem can achieve 33.6Kbit/s with only 3100Hz of bandwidth?
My understanding is that plain old telephone service passes frequencies between 300Hz and 3400Hz. How is it that a V.34 modem in the late 90s would be able to achieve data rates of 33,600bits/s with ...
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How are signal bandwidth and MSPS related?
In various software defined radios, there are three important parameters to set when receiving: frequency, bandwidth and MSPS (million samples per second?). What does it mean to receive with a triple ...
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How Does the RMS of White Noise Change with Sampling Frequency?
There is an analog system which includes the continuous-time linear equalizer (CTLE). With some .noise analysis the power-spectral density (PSD) of the noise in that system is provided. So let's not ...
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Bandwidth of Information Signal
I have trouble finding the bandwidth of a signal. Say I have an info bearing signal m(t)=sinc(2t/pi). I found the fourier transform of the sinc function and found that the angular frequency was 1/pi. ...
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Relation between Bandwidth and Baud-Rate for 8-PSK
I have a query on relationship between Baud Rate and Bandwidth for 8-PSK.
In 8-PSK as 3 bits together form a symbol, so Bandwidth = 2R/3 , R is Bit Rate
As bit ...
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OFDM use a pulse shaping filter or not?
I've heard in various literature that band limited channels use pulse shaping filters. By the way, In OFDM it use a cyclic prefix to overcome ISI, so I wonder if OFDM does not use pulse shaping filter....
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How to generate random data with a specific bandwidth
I generate some random data (bits, actually, using MATLAB's randi) and then I convert such bits to BPSK (1 and -1). After that, I use a RRC pulse (roll-off factor ...
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Specify notch bandwidth by pole placement
I am trying to implement a notch filter by placing zeros and poles. I found in this thread how to specify the frequency to be filtered out (referred to as $\omega_n$ in previous link,) but it is not ...
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Time-Bandwidth Product
The following text is cited from a textbook, "Spotlight Mode Synthetic Aperture Radar: A Signal Processing Approach", I would like to ask if anyone knows the proof to the following statements, as the ...
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Why is bandwidth always limited in a real (physical) channel?
I'm talking about a continuous analog channel.
Why can't it support infinite bandwidth?
Is there a physics reasons for it say for electrical signals?
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Loop bandwidth for symbol timing recovery
I am trying to design the Symbol timing recovery (STR) block of DVBS Receiver.
How should I chose the loop bandwidth and damping ratio for determining the loop filter coefficients $k_1$ and $k_2$?
...
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Extracting multiple signals to baseband
How can I extract a signal to baseband?
Rather that just listen to one signal at a time, I want to take advantage of my RTL-SDR's 2mhz bandwidth and listen to multiple FM signals at the same time. I ...
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Meaning of frequency and bandwidth of a signal, despite the fact that we do not know the signal
First of all, I am completely new to the domain of signal processing.
As far as I know, a signal can be represented with an infinite integral of infinitesimal complex exponentials, which is known as a ...
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Could 2 synchronised RX chains be used to receive a signal too wide for just one of them?
Say the goal is to demodulate a "wide" signal, e.g. 300 MHz wide. An SDR is available with a maximum RX bandwidth of 150 MHz (ADC sampling freq. limitation), but it comes with 2 RX channels sharing ...
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Bounds of higher order derivative of bandlimited signals
Here is a bandlimited function f(t) with bandwidth Ω:
The function f(t) is bounded in [-A,A].
Then the bound of the derivative of f(t) is bounded as:
|f'(t)|≤2πΩA.
So, what is the bound of its n-th ...
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QPSK Data Rate vs Bandwidth at Passband: Why can it only transmit 1 bit per Hz and not 2 bits per Hz?
1) This is a follow up question to the most up-voted answer to this question.
2) The accepted answer is that "QPSK transmits 1 bit per Hz at passband".
3) The theory found in books seems to agree ...
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Should I filter before calculating power, if I'm looking for relative changes in power?
I am building a "scanner" sort of program, which reads IQ samples from an rtl-sdr stick, and keeps track of the power on certain frequencies, in certain bands. I am interested in detecting activity ...
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what does the statement "band limited signal of 5 KHz" mean
A band limited signal of $5$ kHz is observed at the output node whose sampling frequency is $600$ kHz. What is the minimum order of the filter?
Does it mean:
a signal that is from $0$ to $5$ kHz on ...
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Spectrum analyser and resolution bandwidth
For the preliminary part of a lab I had to do, I was asked the following question:
I get how to do 1.1, but with 1.2, I really don't get what's going on; I really would've thought that the resolution ...
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Why we measure bandwith at -3dB?
To characterize a signal it's a common use to determine bandwidth at -3dB from the peak (half power). Also, filter's cutoff frequency is pointed at -3dB. Why we use this rule?
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How bandwidth is used in modulation
In a typical Digital cable environment in the US, the spectrum is divided into 6MHz bands. When a tuner locks to a signal at say 800MHz, I would assume that the band for that signal is 797 - 803 MHz. ...
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Why are real-world digital images not bandlimited?
In the materials about image resampling, it always mentions that real-world digital images not bandlimited. However no explanation
is provided.
For example,
Sinc resampling in theory provides the ...
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Why is the bandwidth doubled with AM?
Let's say I have an arbitrary signal which has the following frequency spectrum and a bandwidth of BNF:
Now I use Amplitude Modulation to transport the signal. The frequency spectrum will change ...
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What is the physical meaning of coherence bandwidth in mmWave massive MIMO channel?
I am doing some research about millimeter wave massive MIMO channel now.
We first take account about static MIMO channel, cause we only have SISO measurement system now.
We use scanner to move our ...
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What does $[-\pi \; \pi]$ band-limited signal mean?
I know that a band-limited signal is a signal which have a limited set of frequencies.
What is then the relation between band limiting and $[-\pi \; \pi]$ since $-\pi$ and $\pi$ are related to ...
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