Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
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1answer
24 views
duty cycle of a WiFi Packet
I am doing a simple over-the-air(WiFi 802.11a) test in a shielded chamber involving one Tx and one Rx (around 5 feet).. I need to find the duty cycle given the length of the payload (in bytes), MCS ...
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15 views
Processing gain-frequency hopped
If you have a 3 MHz signal over a 3 GHz bandwidth, what would be the processing gain using a frequency hopping? What would be considered the hopping and the baseband?
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1answer
48 views
When can a windowed cosine be considered band-limited signal?
I have an exam in the following days and i have no clue of what is the response to this question in the exam:
given this signal:
$$g(t) = H\left(t+\frac{T}{3}\right) f(t) - H\left(t-\frac{2T}{...
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1answer
53 views
sum of 2 signals
I have $2$ signals: $x(t)$ and $y(t)$. They have the same bandwidth $B_x=B_y$. But the bounds for the bandwidth are not the same. For example, $B_x=f_{max}-f_{min}$ and $B_y=g_{max}-g_{min}$ with $f_{...
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2answers
62 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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19 views
Digital Spectrum Analyzer: Video Bandwidth
I am currently working on a Digital Spectrum Analyzer. We are trying to imitate a hardware Spectrum Analyzer by capturing I/Q data and performing an FFT on it. I am a bit stuck on how to imitate the ...
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0answers
25 views
How to add multiple sub bands of frequency into on wide band
Context:
I am doing a project where I have to sample a video signal from a monitor with an SDR. The data is coming in for each pixel left to right top to bottom.
Since my receiver doesn't have a very ...
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0answers
84 views
Do negative frequencies count towards null-to-null bandwidth?
I am aware that negative frequencies do not normally count towards the bandwidth when transmitting in the baseband. However when specifically asked to look at the null-to-null or zero-crossing ...
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1answer
96 views
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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1answer
68 views
Representation, Bandwidth and composition of Digital Signals
I have started learning data communication and I'm not able to grasp certain topics.
First
(i) I know that analog signals are continuous and digital signals are discrete. Analog signal are ...
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0answers
20 views
Doppler Spread and Doppler Spectrum
I am a bit confused about Doppler spread and Doppler Spectrum. I believe the Doppler spread is related to channel coherence time T_c, so that . Due to inconsistencies and incoherency of the channel, ...
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3answers
51 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
177 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
49 views
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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1answer
68 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
144 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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0answers
16 views
What is a transmission rate of 802.11a WIFI radio?
I am trying to understand the transmission rate at which a WiFi radio sends its packets to other radios ?
Like in DSRC (which is 802.11p system) , DSRC Radio broadcasts its message 10 times a second ...
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0answers
104 views
Notch Filter with given Bandwidth
I have to use Matlab with the iirnotch()-function to design a notch filter. The notch should sit at 520Hz, the Bandwidth should be 100Hz and I have a sampling ...
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0answers
19 views
Binary Polar vs 4-PAM Signalling
Why is binary polar signalling not feasible for a data rate of 2.0Mbps within a bandwidth not exceeding 1MHz?
Is it due to the fact that binary signalling can only transfer 1 bit of data per symbol ...
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1answer
73 views
Appropriate channel bandwidth for my BPSK modulated Psuedo-Random code on direct conversion transceiver
My hardware is an analog device SDR+Xilinx FPGA (sdr = fmcomms4-ebz). The direct conversion transceiver (ad9364) has a tunable channel bandwidth of 200Khz - 56Mhz. I am employing BPSK modulation on a ...
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1answer
321 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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47 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
100 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
186 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
304 views
Noise power and bandwidth
$$N=kTB$$
In this formula for calculating noise power, why do we use the total bandwidth of the system?
I mean our signal is at $f_0$ carrier frequency, why is it effected by a large bandwidth and ...
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1answer
509 views
Minimum Channel Bandwidth for PCM
Please check if my answer to GATE IN 2010 question 11.20 is correct/can be improved upon.
So, every $\frac{1}{f_s}$ sec, a sample is taken. The signal amplitude is quantized into $2^n$ levels such ...
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1answer
2k views
Passband vs Baseband Bandwidth
Bandwidth is the difference between the upper and lower frequencies in
a continuous band of frequencies. A key characteristic of bandwidth is
that any band of a given width can carry the same ...
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1answer
53 views
Bandwidth of the Derivative of a Message [duplicate]
If I have a message signal $m(t)$ and it has a bandwidth $B$. I know that the bandwidth of $m^N(t)$ is $NB$. But what is the bandwidth of $\frac{d m(t)}{dt}$?
Thanks!
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1answer
140 views
Bounds of the difference of a bounded band-limited function
For a continuous signal (function), we have Bernstein inequality :
$$
|{df(t)}/dt| \le 2AB\pi
$$
where $A=\sup|f(t)|$ and $B$ is the bandwidth of $f(t)$. The question is: is there a relationship ...
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1answer
60 views
What is an intuitive understanding of the difference between the minimum required bandwidth and actual bandwidth?
When using for example, polar signaling of full width rectangular pulses, the bandwidth is equal to the pulse rate $Rb$, which is also the bit rate.
$B=R_b$ for full width rectangular pulses.
But ...
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2answers
436 views
Quantization level versus bandwidth [closed]
Why is it that increasing the number of quantization levels $L$ results in an increase in the signal's bandwidth?
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2answers
473 views
Bounds of the derivative of a bounded band-limited function
Let $f(t)$ be a function with properties:
$$\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
126 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
65 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 ...
5
votes
2answers
430 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
37 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
875 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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1answer
198 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
53 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
329 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+...
0
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1answer
226 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
427 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
88 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
544 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
138 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
447 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
363 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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0answers
240 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), ...
2
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1answer
295 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 ...
0
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1answer
64 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 ...
