Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
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Mathematics behind bandwidth of product of two signals
I'm just starting to learn about signal processing and I've seen these two posts:
1.What is the bandwidth of product of two signals?
2.Convolution in frequency domain, what is the output bandwidth
...
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19 views
DSSS — Why does bandwidth increase when modulating with a chipping sequence?
Here is an example image:
Why does the bandwidth increase when modulating the carrier with a chipping sequence. All it's doing is phase shifting the carrier sinusoid with -1 and 1 more frequently. ...
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1answer
36 views
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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23 views
Chirp resolution as a function of bandwidth
My question concerns about the Chirp resolution during the crosscorrelation as a function of the sampling rate and available bandwidth. Suppose at a transmitter a chirp signal is transmitted (ranging ...
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1answer
78 views
How is frequency related to data rate?
How does (if it does) frequency affect/relates to Data Rate.
Why for example using the same modulation, LoRa (in the physical layer),
you get somewhere around 250kbps at 2.4Ghz and only 20kbps at ...
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1answer
64 views
What is the meaning of inverse signal bandwidth?
I have been studying the two ray model in communication systems.
The text I'm studying has two signals, $u(t)$, which is Line of Sight and $u(t-t')$, which is the reflected signal.
It quotes,
...
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2answers
60 views
Noise power and bandwidth
$$N=kTB$$
In this formula for calculating noise power, why do we use the total bandwidth of the system?
I mean our signal is at $f_0$ carrier frequency, why is it effected by a large bandwidth and ...
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1answer
104 views
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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1answer
429 views
Passband vs Baseband Bandwidth
Bandwidth is the difference between the upper and lower frequencies in
a continuous band of frequencies. A key characteristic of bandwidth is
that any band of a given width can carry the same ...
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1answer
42 views
Bandwidth of the Derivative of a Message [duplicate]
If I have a message signal $m(t)$ and it has a bandwidth $B$. I know that the bandwidth of $m^N(t)$ is $NB$. But what is the bandwidth of $\frac{d m(t)}{dt}$?
Thanks!
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1answer
126 views
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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1answer
34 views
What is an intuitive understanding of the difference between the minimum required bandwidth and actual bandwidth?
When using for example, polar signaling of full width rectangular pulses, the bandwidth is equal to the pulse rate $Rb$, which is also the bit rate.
$B=R_b$ for full width rectangular pulses.
But ...
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2answers
217 views
Quantization level versus bandwidth [closed]
Why is it that increasing the number of quantization levels $L$ results in an increase in the signal's bandwidth?
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2answers
307 views
Bounds of the derivative of a bounded band-limited function
Let $f(t)$ be a function with properties:
$$\begin{array}{ll}
t\in\mathbf{R}&t\text{ is in reals}\\
f(t)\in\mathbf{R}\text{ for all } t&f(t)\text{ is in reals}\\
|f(t)|<A\text{ for all }t&...
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2answers
100 views
Why Shannon Theorem has nothing to do with frequency?
According to Shannon theorem
$$C= B \log _2(1 + S/N)$$
My question is, why there is no frequency in this formula?
Let's say we have 2 channels, both of them have same 20 MHz bandwidth,
one is from ...
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2answers
47 views
Modulation and allocation in GSM900
I want to do one project and I just want to make sure that I've understood correctly.
Human's voice frequency is around 85-255Hz.
When we talk on phone, carrier is modulated with voice signal in ...
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2answers
276 views
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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0answers
36 views
How can I design a PI controller for a closed loop system, which requires a bandwidth equal to the natural frequency and a set Phase Margin?
For a school project I have to hand in a small report on a this problem. I've been studying so much for it but right now I'm just mixing up everything I've seen and just don't know where to start. I'd ...
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1answer
524 views
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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0answers
55 views
Finding essential bandwidth of the given function
Let the function to be $x(t) = e^{-2t}u(t)$.
I want to find the essential bandwidth of the function to be the frequency at which $|X(jw)|$ drops to $1\%$ of its peak value. With a search, I found that ...
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1answer
135 views
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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1answer
43 views
Separate speech signals that are bandlimitted
I have 2 kind of signals (refer figures) in a folder. One is band limited to 4khz and another is band limited to 8khz, both are with sampling frequency 16khz. I need to separate them. Any idea??
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2answers
217 views
Short length windowed sinc filter
I have a 50-60Hz signal being sampled at a frequency of 25 kHz & I'm trying to filter all frequencies beyond 70 Hz with a reasonable steep transition band (approx 4 Hz) & good attenuation (~40+...
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0answers
35 views
why we use positive side bandwidh when we calculate spectral efficiency
when we calculate spectral efficiency
we devide bit rate by positive side bandwidth
but signal possesses not only positive side band but also negative side band
that is R bps : 2W Hz => R/W bps : ...
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0answers
88 views
Wavelet central frequency
What is the definition of the central frequency of a Wavelet and the bandwidth of a Wavelet? How do they affect the resultant waveform of the wavelet?
Thanks.
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1answer
295 views
Condition for modelling noise as white noise
I am reading a book on Communication System by Simon Haykin. In the topic of white noise there is a paragraph
"We may state that as long as the bandwidth of noise process at input of a system is ...
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2answers
75 views
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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2answers
329 views
Bandwidth of product of two signals
POINT 1: According to convolution theorem, if g1(t) has a bandwidth B1 and g2(t) has a bandwidth B2, then product g1(t)g2(t) has a bandwidth = B1 + B2.
POINT 2: Now, consider an AM waveform s(t)=g(t)...
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0answers
110 views
Parseval's Theorm and Effective Bandwidth
This question says that RMS bandwidth (effective bandwidth) is defined based on the carrier frequency of a signal. This makes intuitive sense to me that the carrier frequency shouldn't determine the ...
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2answers
334 views
Understanding the definition of signal's bandwidth
In class, we have defined bandwidth of a signal as the difference between the maximal and minimal frequency. Also, our tutor explained that the bandwidth indicates how fast the signal is changing.
...
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1answer
269 views
Estimating the bandwidth of various signals
I am trying to estimate the bandwidth of different signals, with different modulations, as seen in a PSD graph. I've heard about a "$3\ \rm dB$ rule" in this context. I don't need extreme accuracy. ...
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131 views
The number of bits per symbol is less than one
For a channel of bandwidth B Hz and signal-to-noise ratio of S/N, i have used Shannon-formula to calculate the maximum channel capacity C. For transmitting at the nyquist baud rate (2 symbol/sec), ...
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1answer
235 views
“Capacity” concept in Shannon Theorem
I have a question about the Shannon Theorem. According to this theorem the maximum capacity of a link can be calculated with the formula:
$$C=B\log_2(1+S/N)$$
where $B$ is the bandwidth and $S/N$ is ...
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1answer
62 views
Clarification on how bandwidth effects input signal
I know that the system bandwidth is the maximum range of frequencies that a system can handle. Is the reason that the input signal gets distorted as the bandwidth decreases a result of fewer segments ...
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2answers
656 views
How to calculate transfer rate and needed bandwidth
I have two questions:
1- If I want to transfer a photo via bluetooth, how should I find how long it takes to transfer? I mean the formula between the image size, bluetooth bandwidth and time.
2- If ...
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1answer
1k views
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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2answers
469 views
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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402 views
Information in GFSK signal
I was measuring a Bluetooth LE Signal, particullary a Channel with center frequency 2402 MHz and Bandwidth of 2 MHz, 2401 - 2403 MHz.
Those measurement points are just the highest peaks.
In the ...
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0answers
204 views
Why does BLE require twice the bandwidth of Bluetooth Classic?
Bluetooth Classic Basic Rate sends data at a rate of 1 Mbps using GFSK modulation in 1 MHz-wide data channels. Bluetooth Low Energy also transmits at that same data rate and modulation, however, it ...
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1answer
380 views
How does one compute the band width of a signal in the time domain $x(t)$?
Sorry if this is a super easy question, I am really not a signals guy (more of a statistician, computer scientist). But I was trying to reconstruct/learn a sinusoidal function $x(t)$ with linear ...
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2answers
6k views
What is the definition of the bandwidth of a signal?
I was reading over the famous Nyquist–Shannon sampling theorem and I was trying to understand what the term bandwidth meant rigorously (exactly) with no ambiguity. In this site the define it as follow:...
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1answer
410 views
Bandwidth and Bit rate
I'm kind of confused about digital transmission.
Is the bandwidth occupied by some digital signal the Fourier spectrum of the bit (pulse) format,or the one determined by the bit rate?
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1answer
23 views
Computing overall bitrate of a transmitter with a two chunks package
I'm programming a digital communication system in MATLAB and I have a two chunk package, let's say a header and a body, and I'm using a different channel code for each chunk, i. e. BHC1 and BCH2. But ...
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1answer
908 views
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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2answers
707 views
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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1answer
150 views
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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1answer
63 views
Conditions for finite bandwidth
I'd like to know which conditions must be satisfied in order to get a signal with a finite bandwidth.
Thank you for your time.
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217 views
How does bandwidth relate to the bitrate?
This might be a really trivial question, but I can't wrap my head around it.
In almost every textbook, we're told that bandwidth (among power and noise), is the factor for both range and bitrate. I'...
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1answer
2k views
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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46 views
How does bandwidth affect a modulated digital signal? [duplicate]
I'm currently reading up on how the lower layers of the ISO/OSI model work and I don't quite understand how broadband communication works yet.
Suppose I want to send some data from point A to point B ...
