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Questions tagged [bandwidth]

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

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0answers
584 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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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 ...
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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 ...
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202 views

Noise analysis with periodogram. problem with different resolutions

I don't understand what happened in my simulation. I would like to perform a trade off between 2 ways to estimate power in frequency bands. I want to detect spurious frequencies. First method: I ...
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0answers
69 views

Varying signal bandwidth with two signal generators

I would like to emulate a signal with bandwidth (like BPSK) for some testing, but the two signal generators I have access to do not have any BPSK options installed. If I know the frequency (2462MHz) ...
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0answers
1k views

Calculating a filter's attenuation at a certain frequency from the Q-factor

I'm using the Web Audio API to make a graphic EQ with four BiQuad filters; a highpass, two bandpass and a low pass: You can see each node representing each filter's frequency. It's working nicely but ...
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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 <...
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2answers
53 views

How to generate random data with a specific bandwidth

I generate some random data (bits, actually, using MATLAB's randi) and then I convert such bits to BPSK (1 and -1). After that, I use a RRC pulse (roll-off factor ...
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1answer
96 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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2answers
63 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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3answers
48 views

Why bit rate is same in a lower frequency spectrum and higher spectrum?

If there is a spectrum between 0 Mhz - 1 Mhz, bandwidth would be 1 Mhz here and for example with baseband we can send 2000 bps. What I can't understand is if spectrum is 5-6 Mhz instead of 0 - 1 Mhz, ...
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1answer
66 views

Bandwidth of a finite impulse response filter

In a machine learning application, a model learns to apply a filter h(n) via convolution to a 1-dimensional input signal s(n) (e....
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1answer
427 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
359 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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2answers
1k 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
215 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 ...
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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 ...
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1answer
585 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 ...
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2answers
233 views

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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2answers
80 views

fundamental question regarding bandwidth

What I've learnt so far is that, if we change a time-domain signal into frequency domain, its bandwidth shows the range of frequency of radio waves that required to generate such signal. However, for ...
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1answer
2k views

Bandwidth of an energy signal

I'm studying for my midterm , and I'm struggling with finding bandwidths. I have this energy spectral density : $\Psi(f)= { 1 \over \sqrt { 1 + ({f \over B }) ^2} }$ , and I need to find the $3$...
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2answers
4k views

Sampling rate in Wifi 802.11 -> 20 MHz enough with a BW of 20 MHz?

In a Wifi 802.11n context, I'm looking to find the sampling rate to perform some processing on the signal and I've something I cannot understand : in the book Next Generation Wireless LAN's: 802.11n ...
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1answer
99 views

Nyquist Maximum data rate formula for PCM

The Nyquist maximum data rate formula for a binary PCM is given by $$C = 2B\log_2L$$ I'm not very sure what "$B$" is here. Is it the bandwidth of the signal being sampled or is it the channel ...
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1answer
140 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 ...
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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?
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1answer
98 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, ...
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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 $f(nT)$? ...
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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 ...
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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
197 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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2answers
304 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
131 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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0answers
268 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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0answers
287 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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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 ...
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0answers
103 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 ...
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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 ...
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1answer
671 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 ...
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0answers
2k views

Minimum bandwidth condition in FSK

I know that FSK occupies a larger bandwidth compared other keying schemes, $$ BW= f_1 -f_2 +2R_b $$ where $f_1$ and $f_2$ are carrier frequencies and $R_b$ is the bit rate. For achieving a ...
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0answers
524 views

Calculate cutoff frequency of filtered data

I am processing data which was put through a low pass filter at some point. Looking at the FFT, I can see that it is less than the Nyquist rate. I am trying to filter another set of data so that the ...
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2answers
122 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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1answer
793 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 ...
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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 ...
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2answers
386 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
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 ...
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2answers
274 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 ...
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2answers
631 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 ...
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3answers
2k views

Bandwidth of a composite signal

How to find bandwidth of a composite signal that can be decomposed into five sine waves with given frequencies and having all peak amplitudes same ?
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2answers
192 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 ...
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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 ...