Questions tagged [bandwidth]

the difference between the upper and lower frequencies in a contiguous set of frequencies

Filter by
Sorted by
Tagged with
0
votes
1answer
660 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 ...
2
votes
2answers
8k 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:...
2
votes
1answer
504 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?
0
votes
1answer
25 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 ...
1
vote
1answer
1k 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 <...
0
votes
2answers
1k 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 ...
4
votes
1answer
221 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. ...
0
votes
1answer
82 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.
1
vote
0answers
283 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'...
3
votes
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 ...
1
vote
0answers
50 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 ...
2
votes
2answers
9k views

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 ...
1
vote
1answer
213 views

Confusion in Normalised Bandwidth of a signal

I know normalised bandwidth can be found from FFT plot of the signal. But I'm confused that at what stage I have to take the FFT. I mean first binary data is input to a convolutional encoder, then to ...
0
votes
1answer
782 views

How do I calculate the bandwidth from a waveform?

Suppose I have a waveform $x(t)$ where $x(t) = 5 + 30\mathrm{cos}(2000\pi t) + 10\mathrm{cos}(6000\pi t)$ that is to be uniformly sampled for digital transmission, how do I calculate the bandwidth of ...
1
vote
2answers
3k views

Bandwidth vs. sampling rate of DAC

What is the difference between the sampling rate and the bandwidth of a DAC? I have found in one paper a DAC speced as 15GHz 3dB bandwidth, and 64GS/s sampling rate, and I haven't been able to relate ...
2
votes
1answer
208 views

Infinite extent of spectrum, but also in time in Oppenheim's Discrete Time Signal Processing?

In Oppenheim's Discrete Time Signal Processing there's on p. 323 no limited band in both time and frequency - wouldn't that violate the Heisenberg Principle?
4
votes
1answer
4k views

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 ...
0
votes
2answers
724 views

bandwidth limited pulse,what window function is it?

I want to know what kind of shape a multiple cycle sine wave pulse ( or maybe the correct term is burst ) should have to have the narrowest bandwidth possible at given pulse width. In the laser ...
0
votes
1answer
1k views

Spectral Effeciency of BPSK

The null-to-null bandwidth of the main lobe of a BPSK signal is twice the symbol rate. BPSK transmits one bit per symbol, so the signal bandwidth is twice the bit rate. That has been shown on a few ...
1
vote
1answer
579 views

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 ...
1
vote
2answers
149 views

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?
1
vote
1answer
96 views

Why the bandwidth of the system with the minimum-order observer is higher than the full-order observer?

In Ogata's Modern Control Engineering (5th Ed., page 786) it says: The bandwidth of the system with the minimum-order observer is higher than that of the system with the full-order observer, ...
0
votes
2answers
270 views

Changing the Bandwidth of a signal of fixed Sampling frequency [closed]

If sampling frequency is fixed, how can I generate a frequency domain signal of a particular bandwidth from a time domain signal of dimension $1\times N$? e.g. if $f_s=100\,\text{kHz}$, how can I ...
9
votes
5answers
792 views

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 ...
0
votes
2answers
630 views

Guard Interval in OFDM

If I extend the length of the Cyclic Prefix (Guard Interval) in an OFDM signal, the loss in data rate is clear by means of the time domain, but I can't see it in the frequency domain as the BW is ...
-1
votes
2answers
212 views

Why does QASK with a same bitrate as BASK use only half of the bandwidth?

I think the title is pretty self explanatory, what else could I add. Why does QASK with a same bitrate as BASK use only half of the bandwidth? Does anybody have an idea about why this is the case? ...
1
vote
1answer
30 views

How to sample $f:=f_{1}\cdot f_{2}\cdot…\cdot f_{K}$?

Let $f_{k}$ be $\sigma_{k}$-bandlimited, $k=1,2,...,K$ and define $f:=f_{1}\cdot f_{2}\cdot...\cdot f_{K}$; then how should I choose $T>0$ such that we can recover $f$ from samples $f(nT)$? ...
1
vote
0answers
102 views

Can picking an inappropriate roll-off frequency for a digital filter just alias the roll-off value?

I believe a related question is asked here, but my question deals more with what filter is realized if one fails to consider design parameters relative to sampling rate. In designing an IIR filter we ...
2
votes
0answers
25 views

Does frequency shifting double needed bandwidth? [duplicate]

Suppose we have a low pass signal and it's spectrum is like this: If we define bandwidth as the difference between signal minimum and maximum frequencies, above picture says that the signal has a ...
2
votes
2answers
2k views

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 ...
2
votes
1answer
139 views

$Q$ factor refers to what on a lowpass filter? (EE kind of definition)

For what I'm learning, the bandwidth (of a BPF, for example) refers to the $\Delta$ between $f_L$ and $f_H$ at (usually) $-3\textrm{ db}$ from the $f_0$ (from wiki). For a peaking filter instead, $f_L$...
0
votes
1answer
200 views

Two question about RBJ Peak filter

I'm new into DSP and Filters in general. Its the first step ahead I do from learning and using a 1-pole IIR basic Low Pass Filter. I'm about to implement for my VST audio application (using C++ and ...
0
votes
1answer
508 views

How to calculate the data rate of IEEE 802.15.4 to be 250kbps? [closed]

How to calculate the data rate of IEEE 802.15.4 to be 250 kbps
7
votes
2answers
1k views

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 ...
1
vote
0answers
258 views

Signal power and signal-to-noise ratio with repeaters

I am trying to solve this question but I am confused on some aspects When solving part B what power signal will we use. Will we use power signal before repeater 2 or after repeater 2 (x5) When ...
1
vote
1answer
665 views

The essential bandwidth of a rectangular pulse

The problem is to estimate the essential bandwidth of a rectangular pulse \begin{equation} g(t) = \Pi(t/T), \end{equation} Where the essential bandwidth must contain at least $90\%$ of the pulse ...
0
votes
0answers
134 views

Zigbee spectrum calculation

I have information related to the wired network topology in a room with the dimensions 50x10x20m. This includes the virtual link information containing source, target and datarate on a particular link....
0
votes
2answers
189 views

Total bandwidth in a network calculation

I have data on the number of devices in a wired network and the data rates on links among these devices. I also know the positions of these devices from which I can compute the distances between the ...
2
votes
2answers
4k views

Root mean square bandwidth of a signal with flat spectrum

I am trying to derive a simple expression for root-mean-square bandwidth $B_{\rm rms}$ for a signal that has flat spectral density over its entire bandwidth $B$. The expression for the $B_{\rm rms}$ ...
2
votes
2answers
120 views

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 ...
0
votes
3answers
6k views

Bandwidth of lowpass filter?

This article here on the Window method for FIR filter design speaks of the total normalized bandwidth of the lowpass filter in $\textrm{Hz}$ (counting both negative and positive frequencies) What ...
0
votes
1answer
101 views

Advantages of 2-VSB vs BPSK?

Both BPSK and 2-VSB transmit one bit of information per smybol and both modulate the real part of the signal. The difference is, as far as I understand, that BPSK does not modulate the imaginary part ...
2
votes
1answer
697 views

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 $k_2$? ...
4
votes
2answers
611 views

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 ...
0
votes
2answers
501 views

Additive Gaussian white noise - bandwidth

The average power at output when additive Gaussian white noise is present is given by the formula below: $$P_0 = \int\limits_{-B}^{B} \frac N2\ df ,\quad \text{with $B$ being the bandwidth.}$$ My ...
8
votes
2answers
7k views

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 ...
0
votes
1answer
90 views

Confusion with regards to units in Sinc pulse

I am currently reading a section in the Handbook for MRI Pulse Sequence book where it says that the time-bandwidth product for a SINC pulse is given by: $$ T \Delta f = Z $$ where $T$ is the length ...
0
votes
2answers
2k views

What is the definition of small/large signal bandwidth?

What is the definition of 'small signal bandwidth' and 'large signal bandwidth'? If I google them, I only encounter them in an electrical context (transistors etc.). However, I am looking for a ...
1
vote
1answer
226 views

Can bandwidth of the closed loop be bigger than bandwidth of individual elements in it?

This is a question from control theory but I hope you can help me with it. I was pointed to this community. So in my control loop I have elements that have cut-off frequency of 3-5kHz and I designed ...
0
votes
3answers
22k views

What is bit rate? How is it related to bandwidth? [closed]

I am very confused about when to use bandwidth as bit rate and where not. Are these terms one and the same?