Questions tagged [bandwidth]
the difference between the upper and lower frequencies in a contiguous set of frequencies
178
questions
1
vote
1answer
34 views
Bandwidth of a modulated signal in analog domain
If i am using QPSK modulation with data rate 4 Mbps with rolloff factor $0.5$, then the bandwidth will be symbol $\rm rate\times (1 + rolloff\ factor)$. So here it will be $\rm 2\ MHz\times 1.5 = 3\ ...
0
votes
1answer
10 views
What is role of BW and frequency in internet speeds?
First the bandwidth (BW):
It is the amount of data that can be transferred simultaneously.just like more no. of highway lanes so that many cars can travel side by side simultaneously.
Frequency
It ...
1
vote
3answers
48 views
What is the physical meaning of coherence bandwidth in mmWave massive MIMO channel?
I am doing some research about millimeter wave massive MIMO channel now.
We first take account about static MIMO channel, cause we only have SISO measurement system now.
We use scanner to move our ...
0
votes
2answers
24 views
Design and a notch filter using two Butterworth filters in parallel (MATLAB)
I am doing a project to filter out a 1kHz noise inserted to a 30sec .wav audio file.
To filter out the 1kHz noise, I am required to design using two Butterworth filters connected in parallel where ...
0
votes
1answer
28 views
Bandwidth and BER of FM0 encoding
What is the bandwidth (i.e., the lowest possible bandwidth) and BER for FM0 encoding?
To be precise, this is my example of an FM0 encoded waveform:
There is always a transition between each bit. For ...
0
votes
2answers
26 views
How come FFT window give half size frequency bands when filter can seems to have an infinite precision?
I don't really understand maths behind filtering but use it lot in music production and i'm a total newbie to DSP.
Usually parametric filters let you filter frequencies with a precision that seems ...
2
votes
1answer
52 views
Detection Bandwidth for Noise Power Calculation
I am trying to calculate the $P_{noise}$ in an experimental setup, such as given
below. The DUT is excited at a predefined frequency, $f$ , with
power $P_\text{in}$. The total power is measured by the ...
-1
votes
2answers
53 views
flat fading and Nyquist minimum bandwidth
For flat fading, the bandwidth of the transmitted signal must be less than than the coherence bandwidth of the channel, and no intersymbol interference (ISI) occurs.
Nyquist showed that the ...
1
vote
1answer
48 views
frequency band and Bandwidth
All I know so far is that frequency is how much a signal repeat it self in a given amount of time (usually one second), like shown in the following figure:
I'm confused with some concepts like ...
2
votes
3answers
317 views
Why we measure bandwith at -3dB?
To characterize a signal it's a common use to determine bandwidth at -3dB from the peak (half power). Also, filter's cutoff frequency is pointed at -3dB. Why we use this rule?
0
votes
1answer
56 views
How to generate IQ samples of a signal?
I am using a HW with LMS7002 RF transceiver chip. This chip takes IQ values as an input.
1. Can anyone point me to a sample IQ value generator? That I can use to test.
2. What will be the IQ values ...
1
vote
0answers
52 views
Calculating the power spectral density on a different bandwidth
Let us say I have the power spectral density for a given bandwidth F1 at a transmit power T. I would like to calculate the power spectral density for bandwidth F2 for 1) the same transmit power T
2) ...
0
votes
0answers
44 views
Bandwidth of a signal
Given a complex,with fmin<0(say -10) and fmax>0(say 30) what is the bandwidth of this signal.Is it form fmin to fmax ,or 0 to fmax?
Thank you!
0
votes
1answer
35 views
What is the unit for power spectrum of acceleration signals in log scale
I have a signal recorded by an accelerometer in m/s^2. It is basically accelerations over a period of time. I have calculated the power spectrum of the signal over in a certain frequency band and then ...
-1
votes
1answer
44 views
Bandwidth and probability of continuous signal
I'm a little bit confused as to how to calculate the bandwidth of a signal. A question has me believing that it is correlated with the probability distribution. I am however not sure of this.
...
2
votes
1answer
43 views
Bandwith of a energy signal
I'm studying for my finals , and I'm struggling with finding bandwidths.
I have this energy spectral density : ĪØ(f)=rect(f) , and I need to find the bandwith, 3 dB band and the band with 90 % power.
...
0
votes
2answers
111 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
1answer
158 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 ...
0
votes
1answer
67 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}{...
1
vote
1answer
89 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_{...
1
vote
2answers
97 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 ...
0
votes
0answers
30 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 ...
0
votes
0answers
27 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 ...
0
votes
1answer
257 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 ...
0
votes
1answer
1k 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 ...
2
votes
1answer
85 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 ...
0
votes
0answers
34 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, ...
1
vote
3answers
156 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, ...
1
vote
1answer
933 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 ...
2
votes
1answer
93 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 ...
1
vote
1answer
138 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....
1
vote
1answer
314 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 ...
0
votes
0answers
236 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 ...
0
votes
0answers
29 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 ...
0
votes
1answer
133 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 ...
2
votes
1answer
813 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 ...
0
votes
0answers
91 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 ...
1
vote
1answer
187 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 ...
0
votes
1answer
345 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,
...
0
votes
2answers
690 views
Noise power and bandwidth
$$N=kTB$$
In this formula for calculating noise power, why do we use the total bandwidth of the system?
I mean our signal is at $f_0$ carrier frequency, why is it effected by a large bandwidth and ...
1
vote
1answer
1k views
Minimum Channel Bandwidth for PCM
Please check if my answer to GATE IN 2010 question 11.20 is correct/can be improved upon.
So, every $\frac{1}{f_s}$ sec, a sample is taken. The signal amplitude is quantized into $2^n$ levels such ...
0
votes
1answer
3k views
Passband vs Baseband Bandwidth
Bandwidth is the difference between the upper and lower frequencies in
a continuous band of frequencies. A key characteristic of bandwidth is
that any band of a given width can carry the same ...
0
votes
1answer
74 views
Bandwidth of the Derivative of a Message [duplicate]
If I have a message signal $m(t)$ and it has a bandwidth $B$. I know that the bandwidth of $m^N(t)$ is $NB$. But what is the bandwidth of $\frac{d m(t)}{dt}$?
Thanks!
5
votes
1answer
149 views
Bounds of the difference of a bounded band-limited function
For a continuous signal (function), we have Bernstein inequality :
$$
|{df(t)}/dt| \le 2AB\pi
$$
where $A=\sup|f(t)|$ and $B$ is the bandwidth of $f(t)$. The question is: is there a relationship ...
0
votes
1answer
88 views
What is an intuitive understanding of the difference between the minimum required bandwidth and actual bandwidth?
When using for example, polar signaling of full width rectangular pulses, the bandwidth is equal to the pulse rate $Rb$, which is also the bit rate.
$B=R_b$ for full width rectangular pulses.
But ...
0
votes
2answers
706 views
Quantization level versus bandwidth [closed]
Why is it that increasing the number of quantization levels $L$ results in an increase in the signal's bandwidth?
8
votes
2answers
626 views
Bounds of the derivative of a bounded band-limited function
Let $f(t)$ be a function with properties:
$$\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&...
0
votes
2answers
156 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 ...
1
vote
2answers
75 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
579 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 ...
