Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
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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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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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Relationship between signal rate, data rate, minimum bandwidth
I need to understand the relationship between bit rate, signal rate and minimum bandwidth. I read in a textbook that
We define three cases for relationship between bit rate and signal rate for ...
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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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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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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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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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Minimum Channel Bandwidth for PCM
Please check if my answer to GATE IN 2010 question 11.20 is correct/can be improved upon.
So, every $\frac{1}{f_s}$ sec, a sample is taken. The signal amplitude is quantized into $2^n$ levels such ...
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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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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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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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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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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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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
$$
\sigma = \frac{\sqrt{\...
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Specify notch bandwidth by pole placement
I am trying to implement a notch filter by placing zeros and poles. I found in this thread how to specify the frequency to be filtered out (referred to as $\omega_n$ in previous link,) but it is not ...
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Is the maximum possible bandwidth of a radar system dependent (or related) to its center frequency?
One of the core parameters of any radar system is its center frequency. Another core parameter is its bandwidth, which is the reciprocal of its ranging resolution. I am wondering: Is there some sort ...
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How to calculate data rate in ground to satellite communication
I want to calculate the data rate in uplink transmission from ground IoT device to satellite.
Is it possible to calculate it with the traditional Shannon equation:
$$R = B \log_2\left(1 + \cfrac{P\...
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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 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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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 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 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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Bandwidth of a modulated signal in analog domain
If i am using QPSK modulation with data rate 4 Mbps with rolloff factor $0.5$, then the bandwidth will be symbol $\rm rate\times (1 + rolloff\ factor)$. So here it will be $\rm 2\ MHz\times 1.5 = 3\ ...
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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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Find Bandwith from Spectral Efficiency and Eb/N0
to give you a short intro of why I am asking here. My Uni is offering a TeleCom Lecture, I love the topic but all they teach is electronics, the exercise sheets are still TeleCom, we get no supporting ...
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Estimating pole radius of formant filter from bandwidth
I wish to design an all-pole formant filter by specifying frequency θ (between 0 and π radians for Nyquist) and bandwidth Φ such that the response of the filter at θ-Φ and at θ+Φ should be roughly 50% ...
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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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Bandwith of a energy signal
I'm studying for my finals , and I'm struggling with finding bandwidths.
I have this energy spectral density : Ψ(f)=rect(f) , and I need to find the bandwith, 3 dB band and the band with 90 % power.
...
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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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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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Aliasing Issues in Sub Band Coding
The general structure of Sub-Band Coding (SBC) is shown below:
The diagram shows that after each of the analysis filters, decimation is performed by a factor M which corresponds to the number of ...
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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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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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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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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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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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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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