Questions tagged [channel]
A channel for communication between transmitter and receiver. Sometimes a channel is multi-input/multi-output, allowing for multiple transmitters and multiple receivers.
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Coordinates of cluster in CDL channel model
I was reading the 3gpp specification to understand the CDL channel models. (See section 7.7.1 and tables within).
It says that for a cluster $C$,it has angles of arrival/departure along the azimuth $(\...
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Impulse response and amplitude-frequency characteristic of a communication channel
The task is to implement communication system for transmission of 32 multiplexed signals through communication channel represented by copper cable whose frequency characteristic is given by:
$$H(f) = ...
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Channel Estimate for OFDM shows distortion for first last order samples
The Channel Gain Estimation was obtained using Least Square method as follows:
Hk= mean(Rx_LTS ./ Tx_LTS, 2); k= -26 to 26
Where Rx_LTS is the received long training sequence (52 samples after ...
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Channel Estimation of OFDM using Long training Sequences
Based on IEEE 802.11a Standards, I am using two Training Sequence-Preamble for Synchronization and Channel estimation.
I have read in some papers that the channel estimation is performed by taking the ...
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How to calculate The Signal-to-Noise Ratio (SNR) in dB (different units)?
Recently, I've ventured into a new domain that I intend to incorporate into my work. After thorough research and consultation, I've found this model to calculate the data transmission rate (Capacity).
...
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Is OFDM equalization performed every 14 symbols?
The number of symbols and slot in a subframe differs depending on the subcarrier spacing
Is equalization processing performed for each slot? Or per subframe?
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What is self-interference channel matrix in full-duplex system?
I am learning about full-duplexing systems, and I saw that we have self-interference (SI) in the systems.
I read some papers that model the SI channel of the base station ${H_{SI}} \in \mathbb{C}^{L \...
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Delayed waves existing MIMO eigenmode transmission
Assume that the numbers of transmitting antennas, receiving antennas, and delayed waves are $N_t$, $N_r$, and $N_p$, respectively. The channel matrix is three-dimensional ($N_r$, $N_t$, $N_p$).
In ...
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How to calculate capacity using Shannon and path-loss?
I am working on tasks offloading on edge computing. I need to find the transmission delay, through calculating Shannon capacity-theoretical maximum data rate- when sending results from the server back ...
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Need to write a simple code in matlab of training sequence or zadoff Chu sequence for my OFDM signal-synchronization
I have written a complete code, in matlab, for my ofdm signal for the transmitter and receiver. Now I want to transmit my ofdm signal via wireless channel using SDR.
Now, I need to combine a simple ...
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GRC implementation for IQ data acquisition of 2-GFSK Radio
I am trying to design a 2-GFSK receiver for acquiring IQ symbols. The aim is to implement the entire receiver chain but the decision stage.
The 2-GFSK waveform is being generated by a standard IoT ...
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Joint channel model for space-air-ground link
Recently I have been interested in the following:
6G for Connected Sky: A Vision for Integrating Terrestrial and Non-Terrestrial Networks
Space-Air-Ground Integrated 6G Wireless Communication ...
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How to understand Fading Channel with no CSI at the Receiver
From the book Fundamentals of Massive MIMO, the section 2.3.4 shows that the expression of the received signal in fading channel with additive non-Gaussian noise and no CSI at receiver is dervied as:
$...
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How to understand the relationship between complex baseband equivalent model and block-fading channel model?
Considering a bandpass communication system, where $y(t)=x(t)*h(t)+n(t)$ ($x(t)$ is the transmitted bandpass symbol, $h(t)$ is the channel impulse response, $n(t)$ is the AWGN, and "$*$" ...
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How correctly choose a channel model?
How correctly choose a channel model: Rician and Rayleigh channel model?
The Rician channel assumes dominant line of sight (LoS) paths from the transmitter to the receiver and other scattering paths. ...
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How to calculate and compensate group delay caused by channel and how to define group delay to wideband signal?
Suppose a wideband signal is sent and received by a RX. If different frequency components travel in different speed then there exists group delay in the signal, right? Not consider the multipath ...
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Tapped Delay Line(TDL) model in 5GNR
In 38.901, there are five channel profiles for TDL models.
Can someone explain the difference among TDL-A , TDL-B and TDL-C for NLOS and which scenario to use them?
Can someone explain the ...
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Distance between Transceiver and Receiver and AWGN
Is there a relationship between the distance between the transceiver and the receiver and the AWGN?
When the distance between the transceiver and receiver increases, the AWGN level decreases?
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Propagation channel model for 5G/6G commmunication
from a course in signal processing, I know some radio propagation models such as Free-space path loss, Okumura model, Hata model, and COST Hata model. They applied to a range of frequencies for up to ...
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How to calculate channel gain for a given setup including path loss, antenna gain and penetration loss
I am trying to reproduce the paper here. I started by generating random $g_{ij}^t$ values but I got lost a bit. If you could help me get $g_{ij}^t$ values for a random distance using the setup ...
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Noise variance estimation
could anyone recommend some articles how to estimate noise variance for the single carriers system with burst mode transmission (preamble+data TDMA)?
My goal at the beginning is to develop skills how ...
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Which are the realictic enviroment will be suitable for TDLC300 channel model?
TR 38.901 Section 7.7.2 mentioned that the TDL-A, TDL-B, and TDL-C channel models are constructed for NLOS scenarios. In TS 38.101-4 Annex B.2.1, in Table B.2.1.1-1 (picture is attached), delay ...
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How to code Rician fading channel gains from k-factor?
I know that MATLAB provides some built-in functions but I am not interested in those. I want to know how can we code to obtain the Rician fading channel gains from normal or Gaussian distributions. ...
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Why does one of my OFDM subcarriers have a much higher gain than the rest in GNUradio?
I'm using a fairly standard setup after the ofdm flowgraph examples provided by gnuradio.
When I look at the absolute value of the received complex symbols in the first sync word (and every other ...
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Related to wireless channel variance?
I am reading wireless research papers and found that mostly the wireless channel is considered to be Zero mean circularly symmetric Complex Gaussian (ZMCSCG) with variance 1 or 2 or 5 or 10 etc.
My ...
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How to estimate Range, Doppler and Angle with FMCW MIMO Radar?
I am trying to obtain the range, Doppler and angle of arrival estimation with an TDM MIMO FMCW radar.
Actually, I have completed this process. In doing so, however, a few things remained unclear. ...
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Undestanding antenna gain applicability
While searching for the info about antenna gain and why it is GAIN I found this interesting example:
If the two antennas in the drawing are “welded” together, how much power will be measured at point
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What is meant by channel knowledge? Difference between partial and full?
Keep coming across the term channel knowledge (specifically in the transmitter) in a reading for class but can't really grasp the idea and don't see a clear cut definition. From what I understand it ...
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How to resolve some inconsistencies in the mathematical model for the narrowband fading channel?
I am reading Wireless Communications by Andrea Goldsmith. There the author mentions that for narrow band channel the received signal can be given as:
$$r(t)=\text{Re} \left\{u(t)\text{exp}(j2\pi f_ct)\...
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Why is there fear of interference between 5G and airline altimeter C-band?
The C-band frequency range to be used for the 5G-advanced rollout is the US is in the 3.7-3.98 GHz range. Whereas altimeters operate in the 4.2-4.4 GHz range. Is there any genuine reason to worry ...
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Simulating Es/N0 by adding noise to analog signal
I believe I am familiar with simulating $E_s/N_0$ by adding noise to the output of the matched filter, but what would be the correct way to simulate $E_s/N_0$ starting with the analog signal at the ...
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Pilot Signal Overhead
I have a doubt regarding Pilot signals such as CSI-RS in NR.
Using a large number of CSI-RS affects Datarate significantly?
or it is negligible?
Because I wonder it is meaningful that optimize the ...
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What does $\mathcal{ E}(|h|^2)$, where $|h|^2$ is power of the channel gain $h$ represent?
I came across this notation of $\mathcal{E}(|h|^2)$ in a research article.
$h$ is the channel gain of a wireless communication channel. In particular, a Rayleigh fading channel.
I know that $|h|^2$ ...
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What are TDL and CDL channel models in principle, and which variation can be used for indoor and outdoor environment, respectively?
I am making a simulation using 5G-toolbox in Matlab. IN 5Gtoolbox we have two kind of channels, CDLChannel and TDLChannel. Now, CDL means Clusteresd Delay Line, and TDL means Tapped Delay Lines. But ...
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Channel Parameters
I'm a newbie in wireless communication.
I found one channel model and have some questions regarding its parameters
In this channel model below..
$\alpha_m,$$e^{j\varphi(k,n)}$, $\tau_m$, $\theta_m$, $...
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Delta dirac function in the Channel model
I have a question about the channel model below.
theta, phi denotes AoA(Angle of Arrival), AoD(Angle of Departure) from receiver and transmitter.
I know that channel impulse response is the sum of ...
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Can a cosine modulated complex valued baseband signal be transmitted over physical channels?
I am reading Digital Communication by Lee and Messerschmitt. In Chapter 6 on modulation, the authors say:
"Modulating a complex-valued baseband signal with a cosine wave yields complex-valued ...
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Multiple Transmitter Localization - Channel Modelling
I read in this paper about to localize multiple transmitter in a wireless scenario. I know from other source that this hypothesis is completely false. What do you think? Is there in the literature ...
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How to estimate optimal channel length for multichannel blind system identification?
Let P1 and P2 two distinct output signals that are generated by a common input signal S. If you want to estimate S using multichannel blind system identification algorithms, you have to specify the ...
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Averaging two channels with Python
I am trying to convert a stereo audio into a mono one by averaging both channels with Python.
My audio is stored in sound and I calculate the average using ...
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How does higher received signal power enable higher data rates?
On page 30, of the book Fundamentals of LTE by Arunabha Ghosh et al. it is written:
This allows broadcast signals
from different cells to combine over the air to significantly enhance the received
...
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Generating a 2D delay-Doppler channel matrix
I was wondering if anyone here has any idea on 2D delay-Doppler channel and how to generate the channel matrix?
Even a hint or a resource would be helpful. I just want to understand and visualize the ...
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Understanding MMSE equalizer equation
I have read many online materials and journal paper where the equation for MMSE equalizer is given as:
$G_{MMSE}$ = $H^H(HH^H+\nu^2I )$
where $H$ is the channel, $H^H$ is its hermitian. $\nu^2$ is ...
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Can Oversampling help to mitigate the effect of additive white gaussian noise?
Oversampling the signal at the receiver's ADC is a common technique to improve the ADC's resolution, dynamic range and to improve the signal to noise ratio (SNR) due to ADC quantizaiton noise, thermal ...
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Optimal FEC option for extremely low SNR situation
I am new to this site, which I joined with the aim of finding someone to help me with a little doubt.
I am trying to design a system that must be able to work at extremely low (the lower, the better, ...
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Centre channel derivation using correlation
I would like to know the algorithm for how centre channel is derived from rejecting left and right channel in audio upmixing process.
Can someone explain intuitively rather than hard hitting ...
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Unstable Phase in Channel Impulse Response
I'm using DW1000 UWB radio transceiver and extract its channel impulse response (CIR). The CIR output by the transceiver is the complex baseband CIR. In a static environment, the CIR is a LTI filter ...
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Channel estimation using bit reversed order of FFT matrix
Is it possible to use the bit-reverse order of FFT instead of FFT to estimate the channel?
Based on my reading, I found that bit reversed order of FFT matrix can diagonalize the channel, but ...
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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....
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How is the Tx/Rx Gain calculated in USRP?
I know that USRPs are uncalibrated devices. In many exampls you can set the so called Tx or Rx gain (as in the picture below).
Now, I know that this does not correspond to the real power of the ...
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