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Although the FRFT has a number of unique properties, it cannot obtain information about local properties of the signal. In addition, the drawback of the short-time FRFT is that its time- and fractional-domain resolutions can not simultaneously be arbitrarily high. As a generalization of the WT, the FRWT combines the advantages of the WT and the FRFT, i.e., it is a linear transformation without cross-term interference and is capable of providing multiresolution analysis and representing signals in the fractional domain. Thus, the FRWT may be potentially useful in the signal processing community and will attract more and more attention.
- In the performance analysis of modern wireless communication systems like the scenario of factory automation with 5G URLLC, which path loss model will be suitable and appropriate to assume?
- Any comments on the recent empirical findings regarding the same?
Thanks in advance.
I am using maximum ratio combing and selection combing techniques for C-NOMA. I want to compare the results for both techniques and also suggest me any other alternative combing techniques which give better results for C-NOMA.
I am trying to analyze the SEP for half duplex relay for UWB channel with PPM TH modulation. I am sure about the analytical part but my simulation results are not matching. I am confused about the decision variable I am using. I am referring the book 'Understanding ultra wideband radio fundamentals by Guerino Giancola'. On receiver side I am using correlation receiver with MRC(maximal ratio combining). I am unable to get any reference paper for this topic.
Thank you in advance
I am trying to analyze SEP for full duplex amplify and forward relay, for MPSK. I am done with the simulation part, but analytical part is not matching with the simulated values. Also the curve I am getting is not smooth in nature. I got the end to end SNR equation for same system model from a research paper. Using that expression in the Craig's formula for SEP, I am calculating the expectation of the integral, which should give me the ASEP. The relay stability factors puts a constraint on the gain.
I am stuck with the analytical part. Any help is appreciated.
Thank you
chapter 11(antennas) of this book: Field and Wave Electromagnetics: Pearson New International Edition - David K. Cheng. ?
So far I only found online versions limited to chapter 10
please consider a frequency selective channel with 3 real coefficients {a1 a2 a3 for the three different frequencies} for example. should we apply average of the multi access interference MAI as: p(user2)*sum(E{a^2}) for the SINR calculation in a 2-user system under this channel? the expectation must be on the users or coefficients? thanks
In LTE TDD special subframes are used for switching from downlink to uplink and contain three sections: DwPTS, GP, and UpPTS. But we don't have any special subframe for switching from uplink to downlink. Why?
Hello All,
I am working on a matlab simulator for SCFDMA PUSCH Uplink considering all the blocks and 3gpp standards. For the simulation purpose we always multiply transmitted signal with a factor because of size difference in DFT and IFFT (zero padding).
For an example:
Let's assume we have the following situation for 1 OFDM subframe (all the parameters are according to 3gpp standard)
>DFT size = 816, (allocated resource blocks = 68)
>Modulation order = 2 (4 QAM),
>Total symbols after DFT and before resource mapping = 816*12 = 9792,
>Total resource block = 100, (zero padding while resource mapping)
>Total symbols after resource mapping = 1200*14 (816*2 dmrs and zero padding)
>IFFT size = 2048, (zero padding before IFFT)
>Cyclic prefix (normal) length = 160*2 (for first symbols) + 144*12 (for others) = 2048
>Total symbols transmitted = 2048*14 (after IFFT) + 2048 (CP) = 30720
Now for the simulation purpose
(i)
transmitted_signal = transmitted_signal*sqrt(ifftSize/(PRBAllocated*12))*sqrt(length(transmitted_signal)/(ifftSize*14))
(ii)
EsNo = EbNo + 10*log10(DFT_length/IFFT_length) + 10*log10(modOrder);
Are both the statements valid? How?
Do I need to consider CP and DMRS effect in second expression?
As for linear ZF or MMSE detector, the coefficient of soft output is that symbol power over symbol interference power plus white noise power.
As for non-linear ZF-SIC or MMSE-SIC detector, the coefficient of soft output is that symbol power over symbol interference power plus not only white noise power but also error propagation power of decision feedback.
Does anyone know how to calculate this factor of error propagation power of decision feedback, and get a correct LLR value.
Many thanks
Jiajun Zhu
I am studying how to establish a 802.11ac multipath channel for my WiFi simulation.
As we know, the impact of channel is equivalent to that the transmit signal go through a "channel filter". Therefore, the specification provides the coefficients of channel taps to us so that we can build the "channel filter".
However, It is based on that the sampling rate of baseband signal is equal to that of the "channel filter".
The problem I found that my baseband signal has the sampling rate of 80MHz, but the channel tap spacing is 5nsec (100MHz). There are different sampling rates!
Then, how can I do for the mismatch of sampling rates, and get a correct simulation?
Kind Regards
Jiajun Zhu
I would like to generate CSCG in MATLAB with zero mean and certain variance. I would be pleased to know all the possible ways of generating CSCG noise.
Thanks
If we were able to estimate the noise power blindly for a conventional energy detector (CED), does that shift the CED from semi-blind to fully blind detector?
if we have 2 devices like walky talky and mobile phone, for a particular situation, is it possible the mobile to use the channel allocated to walky talky to send data/information ?
Land Mobile Satellite Channel Modeling
In general adaptive time-varying filters are used for acoustic echo cancellation (AEC) and active noise suppression. In non-linear AEC we assume there is low or no noise when cancel the echo with adaptive filters. My concern is to find algorithms or adaptive filter structures that can manage both the issues simultaneously without any performance degradation.
Kindly help me in getting some new idea in this direction.
Regards,
A.Kar
Can I use ftp to send data to remote locations using GSM links.
Since 2G/3G links are not always good, what kind of file transfer protocols can best suite the task of sending/receiving data using the 2G and 3G links?
The reference I've read indicates that the minimum training frames should be greater or equal to the number of transmitter antennas. Herein, the training frames denote that S = [s1, s2, s3, ... sN], where si is a nTx*1 vector and N is total number training frames.
When I choose Least square estimation LS = S' * inv( S * S' ) to achieve the channel estimation, I find that sometimes Matlab displays "Warning: Matrix is singular to working precision. ". Then the estimation is incorrect. If I increase the training length, the number of this cases appearance declines.
So, what is the problem in this case? How can I determine the training length to avoid the problem in reality?
Having been around in one form or another for almost thirty years, software defined radio (SDR) is still in its infancy, relegated to the research lab or the hobbyist study. Every year, more and more publications declare that some recent advances in computing power, or microprocessor architecture/augmentation, have paved the way for future systems to be completely software defined. Yet, mass market products are, invariably, hardware-defined.
What is the hold-up? Is it really limited computing power or lack of resources? Is it simply not a profitable venture?
Should we accept that, despite our best intentions, the world simply does not want, or need, SDR? Is it time to accept that SDR is just a research convenience, an interesting side-project, and re-focus our efforts on pushing the boundaries of hardware-defined receivers?
Or perhaps the momentum is still gathering, and there really is a future in SDR?