Questions tagged [bandwidth]

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

212 questions
Filter by
Sorted by
Tagged with
106 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 : Ψ(f)=rect(f) , and I need to find the bandwith, 3 dB band and the band with 90 % power. ...
176 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 ...
48 views

Why is the bandwidth of each ZigBee channel in the 2.4GHz frequency band 2MHz, while the sampling interval of the ZigBee receiver is 0.5us? [duplicate]

From the Wikipedia, the XBee paper, the BlueBee paper, and the WeBee paper, I learned that: In the 2.4 GHz band, the bandwidth of each ZigBee channel is 2 MHz. For receiving a signal over one of ...
74 views

Bounds of higher order derivative of bandlimited signals

Here is a bandlimited function f(t) with bandwidth Ω: The function f(t) is bounded in [-A,A]. Then the bound of the derivative of f(t) is bounded as: |f'(t)|≤2πΩA. So, what is the bound of its n-th ...
78 views

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 ...
301 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....
21 views

Are the SNR, Data Rate and Delay values correct in the below calculation?

I have these values: power_received_from_one_subcarrier = -80 dBm bandwidth_for_one_subcarrier = 180 KHz noise = -109 dBm When using {/, *}, the dBm values are ...
150 views

How can I experimentally find the bandwidth of my PLL?

I recently designed a phase-locked loop. I would like to quantify its bandwidth so that I can better understand it. However, I made this bandwidth in an informal manner due to my lack of formal ...
52 views

Time domain representation of a modulated signal when symbol rate >> carrier frequency?

I need to understand the relationship between carrier vs. bits with PSK modulation, and what the signal in the time domain would look like if my symbol rate is far greater than my carrier frequency. ...
900 views

Minimum sampling frequency, quantization, and bitrate calculation

An analogue sensor has a bandwidth which extends from very low frequencies up to a maximum of 14.5 kHz. Using the Sampling Theorem what is the minimum sampling rate (number of samples per second) ...
37 views

Aliasing Issues in Sub Band Coding

The general structure of Sub-Band Coding (SBC) is shown below: The diagram shows that after each of the analysis filters, decimation is performed by a factor M which corresponds to the number of ...
80 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 ...
212 views

Bandwidth of PSK modulated signal

What does it mean that the bandwidth of PSK modulated signal without applying any filtering or shaping of the pulse, is equal to the sampling rate with "1st lobe" equal to two times of ...
132 views

Spectral properties of QPSK modulation

From what I've read, the spectral properties of the modulation largely depend on the rate of change of the signal phase - "a signal in which the phase changes stepwise has a broad spectrum, well ...
61 views

Calculating transmitter power from spectral density

I want to find out what is the real transmit power of my USRP 2922, unfortunately the only results I get when looking at the spectrum analyzer is the spectral power density. These are the results of ...
144 views

43 views

the best pre emphasis for MMSE equalizer

The system consists of multiple low-pass filter and noise, $h_1$, $h_2$, $h_3$, ..., $n_1$, $n_2$, $n_3$, ... At the transmitter, the power of signal is fixed; and at the receiver, MMSE equalizer is ...
269 views

Why the bandwidth in frequency spectrum of AM wave is 2fm and not 2fc?

We know, the instantaneous voltage of AM wave is: ...