Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
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Inter symbol interference
I understand the Nyquist criterion in the frequency domain, which specifies that for zero inter-symbol interference (ISI), the signal's bandwidth should be limited to $\frac{R_{b}}{2}$, where
${R_{b}=\...
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Accounting for bandwidth in spectrum data
I'm looking at the USGS Spectral Library, and spectra are represented with the center wavelength, bandwidth, and amplitude value for each channel. I assume that a wider bandwidth will result in larger ...
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very basic confusion about the bandwidth of constant signal function
I have a very basic question about bandwidth of constant function $f(t) = K$.
As the Fourier transform of a constant pulse is a delta-function centered at zero frequency, the bandwidth (maximum value ...
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What is the most used signal for basic pulse?
My professor said that: in order to avoid interferences/harmonics caused by the nature of the square wave g(t) (sinc will have these secondary lobes), it's better to change the basic pulse g(t) to ...
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DAC/ADC sample rate selection for modem
So I have a very basic on which I couldn't find much details anywhere.
I'll start with an example:
I have to transmit 100Mbps of BPSK data. Roll-off factor is 0.25.
This data will be processed at ...
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Bandwidth of a complex pole
Text from "Fundamentals of Speech Recognition (Rabiner)".
A complex pole of the LPC model spectrum can be expressed as $Z_i =
> r_i \cdot e^{j \omega_i} $, where $r_i$ and $\omega_i$ are ...
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Is the constant signal $x(t)=1$ bandwidth limited?
A quick question I was asked by a friend for homework.
We have an LTI system and we needed an example for reconstruction and such...
Anyway, he asked me if the constant signal is bandwidth limited.
...
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Understanding frequency band specification in wireless networks
I am trying to clear my understanding of frequency bands.
When a particular wireless network standard like WiFi 6 claims operation in the $2.4$ GHz or $5$ GHz band, what do these values refer to? I am ...
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Bandwidth of an entire song
My question has to do with the difference between the frequencies of a single note, and the frequencies of an entire song.
If I have a 5 second signal of the form:
$x(t)=\sin(8\pi t)$, here is the ...
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Choosing a suitable modulation format
I'm trying to deal with this question about multiplexing and choosing an appropriate modulation format. It's in two parts.
(i) You need to design a system for the transmission of surround audio ...
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Why are all baseband signals low-pass?
A baseband signal is just a signal that has not been used to modify a carrier signal. Now, I have noticed that all baseband signals are low-pass too. Why is that?
I can understand why digital baseband ...
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What does the bandwidth of a medium even mean?
Whenever the bandwidth of a medium linking two devices is greater than
the bandwidth needs of the devices, the link can be shared.
Multiplexing is the set of techniques ...
Forouzan, Data ...
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DAC sampling rate when using DSSS/CDMA
I'm currently not sure if I understood DSSS correctly.
Following example:
We have a shared RF network with around a thousand of users and we want to use CDMA. The RF link should allow the streaming of ...
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Measuring thermal noise of RLC circuit
I am confused about Johnson-Nyquist noise. Specifically, where does bandwidth come in?
Thermal noise voltage is usually defined as something like: V^2=4kT∫R(f)df, integrated over a bandwidth.
I am ...
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Does bandwidth include negative frequencies?
I've seen countless definitions of bandwidth that disregard negative frequencies.
Is that done due to the symmetrical nature of a certain signal eg. a cosine or due to the inherent lack of meaning ...
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Clarification on video about frequency deviation in phase modulation bandwidth
I am watching this video and at 7:12 he calculates the frequency deviation $\Delta f = f_{c}f_{m}A_{m} $ where the $c$ underscript is for "carrier" and the $m$ underscript is for "...
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Meaning of roll-off factor 0.5 and bandwidth
We currently have a radio that is transmitting at the following RF params:
Modulation: OQPSK
Data rate: 500Kbps
Uplink coding: BCH
I am interested in understanding what is the associated uplink ...
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In the RMS bandwidth equation, why do we have the energy of the signal in the denominator?
In the following equation:
$$B_{\rm rms}^2 = \frac{\displaystyle\int_{-\infty}^\infty f^2\lvert G(f)\rvert^2df}{\displaystyle\int_{-\infty}^\infty \lvert G(f)\rvert^2df}.$$
It is not clear why do we ...
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spectral bandwidth of QPSK signal
When running the MATLAB QPSK transmitter and receiver example (found here: QPSK Tx and Rx Example) you can see on the plot of the spectrum that the bandwidth is ~80kHz.
If we double click on ...
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Bandwidth transmission for uniform PCM using m-ary PPM
I have a uniform PCM whose bandwidth is W = 1Hz and n = 12 bits, i.e. the transmission bandwidth B_T = n*W = 12Hz.
Given this features of the signal, I need to calculate the minimum transmission ...
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LTI system tradeoff between gain, bandwidth, and delay
For first-order LTI systems, the gain-bandwidth constant is often discussed. I've seen the claim that in general, gain and bandwidth don't directly trade off with each other as much as delay. For an ...
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How to calculate the bandwidth of a continuous signal in an interval?
I am struggling with a task I thought would be a good exercise. I am tasked with calculating the bandwidth of the equation below and I'm struggling. I managed to find and understand why $\text{sinc}(t)...
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Spectrum analyzer resolution bandwidth (RBW) for LTE signals
I am trying to measure the maximum output power of an SDR transmitting a 20 MHz LTE signal with a spectrum analyzer.
Adjusting the resolution bandwidth (RBW) changes the power spectral density (PSD) ...
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Maximum bandwidth of radio-frequency filter to avoid the image frequency
Consider the following super-heterodyne receiver
The carrier frequency of the local oscillator is chosen to be
$$ f_{LO} = f_c + f_{IF} \tag{1} $$
where $f_c$ is the transmitted carrier frequency and ...
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Can frequency multiplier (e.g. doubler) impact signal bandwidth?
My understanding is that if a single tone at frequency F is inputted to the frequency doubler, one should observe at its output in the spectrum the same tone but now at a frequency 2F.
However, what ...
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Cutoff frequency condition of input signal so that it can be reconstructed , given frequency response (Answer explanation?)
For the following system:
We have:
$$r(t) = s(t) + Ks(t-\tau)$$
where $|K|< 1$, with the following impulse response $h(t)$ and frequency-response $H(f)$:
$$h(t) = \delta_0(t) + K\delta_0(t-\tau)$$
...
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How does carrier size / bandwidth effect propagation
I'm working with software-defined coded orthogonal frequency division multiplexing radios.
They have a choice of bandwidth, 1,2,3-20MHz.
Of course, as you increase your bandwidth (carrier size), you ...
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Is the maximum possible bandwidth of a radar system dependent (or related) to its center frequency?
One of the core parameters of any radar system is its center frequency. Another core parameter is its bandwidth, which is the reciprocal of its ranging resolution. I am wondering: Is there some sort ...
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Is my solution correct?
$\textbf{Question:}$
$y_a(t)$ is a rectangular waveform defined as:
$$\
y_a(t) =
\begin{cases}
2 &t \in [0,1/25)s\...
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Why does the bandwidth of a signal need to be half of the sampling rate? [duplicate]
Suppose I perform a DFT on some function with sampling rate of $\frac{1}{\Delta t}$. According to this page, the bandwidth, which is the maximum frequency that can be analyzed when performed the DFT, ...
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How to achieve 3 Gbps with 210 MHz bandwidth in 5G?
I read an article from T-Mobile link where they claimed a 3Gbps speedtest with the aggregation of 3 three bands in 5G.
How it is possible to make 3 Gbps with a 210 MHz bandwidth and using 256QAM in 5G?...
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Bandwidth for Noise Calcuation FMCW Radar
I am trying to determine the thermal noise for a Frequency modulated continuous wave radar. The radar is the TI IWR6843 chip. Currently, I am using the radar to transmit a chirp with a bandwidth of 4 ...
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How to calculate data rate in ground to satellite communication
I want to calculate the data rate in uplink transmission from ground IoT device to satellite.
Is it possible to calculate it with the traditional Shannon equation:
$$R = B \log_2\left(1 + \cfrac{P\...
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One-sided bandwidth of the Gaussian filter
As defined in the CCSDS (section 3.1.2), the impulse response of the Gaussian filter is given by
$$
h(t) = \frac{1}{\sigma T \sqrt{2\pi}}e^{-\frac{t^2}{2\sigma^2T^2}}
$$
where
$$
\sigma = \frac{\sqrt{\...
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Bandwidth of cosine of bandlimited signal
I have a signal $x(t)$ with bandwidth $B_x$, and I am taking its cosine to create $y(t) = cos(x(t))$. After checking the spectrum with FFT, it seems that $y(t)$ is also bandlimited. But, is there a ...
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Minimum bandpass bandwidth?
Is there any restriction on decreasing the bandwidth (beyond the sampling rate) that I should be aware of when filtering a signal with a bandpass? My intuition tells me that the quality of the result ...
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Rayleigh Bandwidth Calculation-Radar
I am trying to generate a simple Gaussian pulse that has a 1 ns pulse width. However, when I generate the pulse, I realized that I did not meet the condition that calculates Rayleigh Bandwidth (1/...
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What is the optimal transient for turning on a harmonic signal with minimal bandwidth?
Given a harmonic signal of a certain frequency and amplitude, what is the optimal way of "turning on" this signal from zero to full amplitude within a given time window under the constraint ...
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gnuradio , SDR usrpx300
I use usrp x300 SDR.
I'm confused about Bandwidth and sample_rate. How do I calculate
them? is ...
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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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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 to solve this degree $2N$ polynomial equation of filter's cut-off frequency?
In a paper I am interested in, the following equation is given to determine the cut-off frequency $\omega$ of a filter:
$$t^{2N}+\left[-2\left(1-\frac{1}{2Q^2}\right)\right]t^N +\left[-\left(\frac{|H(\...
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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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Bandwidth visualization in frequency domain
Consider some signal in frequency domain:
the maximum length of which corresponds to the half of the original signal ($N/2$), here $N=32$.
It is known that the bandwidth of each sample is $2/N$, so ...
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What is the intuition explaining the Shannon-Hartley theorem?
In the digital domain, the signal to noise ratio (SNR) may be interpreted loosely but usefully as the number of discrete or quantized levels one can transmit reliably. For instance, loosely speaking, ...
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How to generate wideband Gaussian white noise
I want to generate correlated complex white Gaussian noise signals in MATLAB. What I do is that I take complex Gaussian random variables with unit-variance and multiply them with the desired input ...
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How the bandwidth distance product rule is applied?
I read the following in one reference:
A copper wire (twisted pair), the link traditionally associated with low bit rate transmission, is still in use in the modern data centers transmitting data at ...
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What is the symbol rate achieved with raised cosine filter?
The bandwidth of the raised cosine filter is w=0.5(1+r)Rs, where Rs is the symbol rate, and r is the roll-off factor. r=0 represents the Nyquist filter, for which Rs=2w.
Any higher value for the roll-...
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How do you prove that the bandwidth of a signal is inversely proportional to the length of the signal?
I am trying to prove the below identity where $f_c(x)=f(cx)$ such that c is a positive number.
$F_c(\alpha)=\frac 1 c F(\frac\alpha c)$
F above represents the Fourier transformed $f(x)$. I attempted ...
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Are there any techniques that can achieve higher transmission rate than Shannon capacity?
The maximum bit rate that can be transmitted over a channel with bandwidth B is determined by Shannon C=B log(1+S/N)
Are there any techniques that could break this limit?
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