Questions tagged [bandwidth]

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

Filter by
Sorted by
Tagged with
3
votes
1answer
1k 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 $k_2$? ...
6
votes
3answers
2k views

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 ...
10
votes
2answers
959 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&...
1
vote
2answers
921 views

Find the Equivalent Noise Bandwidth

I have already asked (in another thread) how to quantify (specify) the window function I have created. One figure I need it seems is the Equivalent Noise Bandwidth (ENBW) Or Noise Equivalent Bandwidth....
4
votes
1answer
8k 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 ...
7
votes
2answers
2k 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 ...
4
votes
2answers
1k 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 ...
2
votes
2answers
14k 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
2answers
306 views

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....
2
votes
2answers
288 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?
2
votes
1answer
17k views

How to calculate bandwidth require for OFDM

I read LTE PHY profile and do not understand the relationship between number of FFT and bandwidth. For example LTE downlink channel bandwidth 1.25MHz and 5MHz have 128 FFTs and 512 FFTs accordingly. ...
2
votes
4answers
122 views

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 ...
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
2k views

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. ...
1
vote
1answer
6k 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 ...
0
votes
2answers
8k views

Essential Bandwidth of rect(t/T)

Here is a question I have been trying to solve: Estimate the "essential bandwidth" of a rectangular pulse $$ g(t) = \operatorname{rect}\left(\frac{t}{T}\right), $$ with $T>0$, where this "...
0
votes
1answer
6k views

How to calculate the required bandwidth from a spectrum diagram? [FM]

For example from this diagram.
9
votes
2answers
12k 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 ...
13
votes
3answers
20k views

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 ...
11
votes
5answers
1k 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 ...
4
votes
1answer
3k 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 ...
6
votes
1answer
14k views

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}...
1
vote
2answers
340 views

Confused on Pulse Filter Bandwidth and Symbol Rate Relation

***Still need help in 2021 - not fully clear still on Jan 20th *** I am confused about the relation between Sinc and Rectangle transform pair and how that relates the Bandwidth of Pulses, Bandwidth of ...
4
votes
1answer
2k 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 ...
2
votes
1answer
849 views

Calculating Data Rate using Bandwidth, Transmission Power, Noise Power Spectrum Density and Channel Gain

I'm a Software Engineering student researching on Load Balancing in IoT and I need to calculate data rate. However, I don't know how to use these values to attain data rate despite searching on the ...
2
votes
2answers
6k 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
1answer
302 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?
2
votes
2answers
11k 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:...
4
votes
1answer
329 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. ...
3
votes
1answer
758 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 ...
0
votes
1answer
158 views

Bandwidth of a trimmed sinus wave

I generate a sinus which duration is 15ms and frequeuncy of 13KHz. Is its bandwidth is (1/15ms) ? Or in other words, BW = 66.6Hz? I ask that because I have two freqs in my system: 13K & 13.1K. I ...
0
votes
2answers
207 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 ...
0
votes
2answers
208 views

What's the theoretical bandwidth?

A radio signal is sampled at $f_{s}=5512$ Hz, and $n=2^{14}=16384$ points are used in the FFT to display it as a spectrogram. The frequency resolution is $\frac{f_{s}}{n}=0.33642578125$ Hz/point, ...
0
votes
2answers
535 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 ...
0
votes
0answers
185 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
789 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. ...