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Simyon Pinsky (@SenSen)


Range Doppler of an FMCW Radar.

New thread started 4 years ago
Plotting the Range Doppler of an FMCW Radar developed for Vital Signs. The FMCW radar with the following parameters was implemented: %System parametersValue...
A radar using a ULA with a large number of elements(for instance N=150 for 1[deg] beamwidth[1]) is being designed. After the Range and Doppler processing, Digital...

FMCW MIMO radar RX post processing pipe.

New thread started 6 years ago
Currently working on a FMCW MIMO radar RX pipe consisting of the following modules:1. 2D CFAR – processing the Range Doppler images per Angle.2. 3D clustering...
Given the required Probability of False Alarm(Pfa) and the number of training cells(N) of SO-CFAR, wondered what would be the correct method for threshold factor derivation...
Interested to determine the size of the FFT used by a proprietary video link transmitting 720p@30fps video. (This can usually be achieved by 5-10 Mbps bit rate)....
This is a propriety video link being BLINDLY demodulated.No parameters are given/known.There was however a progress with the problem, no bits yet though. Will update...
Given an unknown OFDM symbol consisting of 9144 samples, interested to know the size of the FFT used in the TX/Number of bins. Downsampling to 512,256,128,64,32...

Re: OFDM Constellation.

Reply posted 6 years ago (09/28/2018)
Following the previous post, progress was made. Seems that the data bins of the symbol are QPSK while the pilots are BPSK. The following summarizes the findings...

Re: OFDM Constellation.

Reply posted 6 years ago (09/26/2018)
The timing and frequency synchronization is done using the blind CP based method[1], which was implemented and tested for simulated WiFi signal.Examining the indexes...

Re: OFDM Constellation.

Reply posted 6 years ago (09/25/2018)
Thank you for the reply.The question relates to the two areas marked belowconst2.jpg

Re: OFDM Constellation.

Reply posted 6 years ago (09/25/2018)
The ML Blind demodulator functionality was tested using simulated signal(related document sent in private email to info@ortenga.com). I wonder whether the additional...

Re: OFDM Constellation.

Reply posted 6 years ago (09/25/2018)
Thanks.Not sure what do you call circle.Below the two unexpected areas are marked.const2.jpgThe demodulate is very simple and works on the first training symbols,...

Re: OFDM Constellation.

Reply posted 6 years ago (09/25/2018)
Correct.Working on blind demodulation(using Matlab) of recorded OFDM signal."Each square" is the IQ of a symbol of the up-sampled burst.

Re: OFDM Constellation.

Reply posted 6 years ago (09/25/2018)
Hi Shahram,Sorry for not being clear.This is a recorded signal.Each burst consists of 2(LFSR)+14(Data) Symbols.The three plots varies in the value of SNR coefficient...

OFDM Constellation.

New thread started 6 years ago
Currently testing Blind Demodulation methods on recorded OFDM signal. The recordings were done with coax cables. While the estimated Frequency and Time shifts were...

Re: RF switching matrix for DOA.

Reply posted 6 years ago (07/26/2018)
Thank you for the fast and insightful comment. Connecting a receiver to each antenna can not be considered, as the system must be as low cost as possible. As a...

RF switching matrix for DOA.

New thread started 6 years ago
Interested to design an RF Switching Matrix driving a <6Ghz signal from 5 antennas to 2 RX Channels, of the following structure:The possible inputs into the receiver...

Re: 1D MUSIC DOA.

Reply posted 6 years ago (07/12/2018)
Thank you Y(J)S.Seems that UCA will be required to overcome the ambiguity, and gain the elevation as well as azimuth estimation.Taking into account that most of...

Re: 1D MUSIC DOA.

Reply posted 6 years ago (07/11/2018)
Thank you Y(J)S. I understand the geometry. projection2.pngSeems that the error in the estimated angle can be expressed as: alpha – alpha’ = atan(y0/x0)-...

Re: 1D MUSIC DOA.

Reply posted 6 years ago (07/10/2018)
Thank you.Will review the "Resolving Manifold Ambiguities in Direction-of-Arrival Estimation for Nonuniform Linear Antenna Arrays".Wondered what is your opinion...

1D MUSIC DOA.

New thread started 6 years ago
Hello, I am currently working on a MUSIC algorithm for DOA of RF emitters in 3D. At the first stage, interested to apply the 1D MUSIC using a linear array of...

Re: Semi-blind OFDM channel estimation.

Reply posted 8 years ago (04/26/2017)
Hi David. I am not sure how should the transfer function of the channel be combined/derived given the training sequences as elaborated in the document. You can...

Re: Semi-blind OFDM channel estimation.

Reply posted 8 years ago (04/26/2017)
Hi David, Thank you very much for the detailed answer. After working with the two training sequences, still have several open issues. The elaboration can be seen...

Re: Semi-blind OFDM channel estimation.

Reply posted 8 years ago (04/24/2017)
Hi David. Using the signal, the frequency and the timing technique as before, I have examined 3 Symbols, following the Preamble:The absolute value of the three...

Re: Spectrum Sensing HW.

Reply posted 8 years ago (04/22/2017)
Following a further research, it does not seem to be possible to perform the sensing in the required range using wifi routers only, due to their limited bandwidth. As...

Re: Semi-blind OFDM channel estimation.

Reply posted 8 years ago (04/21/2017)
Hello David. Once again – thank you very much for the assistance. Will analyze the signal according to your comments and post an update soon: Currently using...

Re: Semi-blind OFDM channel estimation.

Reply posted 8 years ago (04/19/2017)
Thank you Slartibartfast for such a fast reply.The preamble was derived following a signal analyzis.The pilots will be derived based on statistics of the data symbols.In...

Semi-blind OFDM channel estimation.

New thread started 8 years ago
Hello. I am currently working on a semi-blind #OFDM channel estimation. After analyzing the recorded signal(sampling frequency is known), and deriving the following...

Re: Spectrum Sensing HW.

Reply posted 8 years ago (04/17/2017)
Hello Cogwsn.Thank you for the reply.Please see the answer to Motilito.

Re: Spectrum Sensing HW.

Reply posted 8 years ago (04/17/2017)
Hello Fred.Thank you for the reply.Please see the answer to Motilito.

Re: Spectrum Sensing HW.

Reply posted 8 years ago (04/17/2017)
Thank you - Motilito, Fred Marshall and Cogwsn for the detailed and fast reply. The proposed SDRs(LMS6002D/AD-FMCOMMS2/Ettus) are all good platforms indeed. As...

Spectrum Sensing HW.

New thread started 8 years ago
I am interested to use an existing hardware to perform a spectrum sensing/monitoring in the frequency range of 2.2-2.6[Ghz]. Taking into account that the 802.11ac...

Re: OFDM Burst Preamble.

Reply posted 8 years ago (04/03/2017)
Short update.The time and frequency tuning of the signal described above, yields LFSR based preamble pattern, as can be seen below:fig1.pngHowever, same approach...

Re: OFDM Burst Preamble.

Reply posted 8 years ago (03/27/2017)
Thank you David.Regarding the original sequence, our findings are aligned. Using the shifted diff as well as cross and auto correlation of different segments of...

Re: OFDM Burst Preamble.

Reply posted 8 years ago (03/25/2017)
Hello David.How are you?Thank you for the detailed answer regarding the previous data set.I will review it carefully tomorrow, and update.As to the post above -...

OFDM Burst Preamble.

New thread started 8 years ago
Hi.While analyzing an OFDM signal sampled at 40Mhz, with the following Spectrum:fskorofdm1.pngUsing mainly cross-correlation, preamble of the size 3658 samples is being...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (03/09/2017)
Hello David.Thank you very much for you interest.Following our last correspondence on the issue, and thanks to your help, the issue was solved.The frequency was...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (02/02/2017)
Hello David.Thank you very much for the help.In the beginning, the FHSS_2 was examined to be aligned to your answer from January 21, 2017 . However, according to...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (01/29/2017)
Hi David, Once again - thank you very much for the highly detailed answer. I have tried to follow your instructions, however, did not receive the same results. Wonder...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (01/24/2017)
Hello David.Thanks a lot for the detailed explanation.Will analyse offline and update soon.

Re: FHSS Signal Analysis.

Reply posted 8 years ago (01/22/2017)
Hi David. Thank you for the reply. The spectrum is indeed OFDM like, however, the constellation used(QAM4/16/…,) can not be identified. Applying  a high resolution...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (01/21/2017)
Hi David, Further study of the signal indeed reveals the symbols and the CP. CP_size = 1/8*Symbol_Duration Symbol_Duration=3656 However, after LP filtering,...

Re: FHSS Signal Analysis.

Reply posted 8 years ago (01/18/2017)
Thank you for the detailed and very helpful answer.P.S.Seems to me that there are 3 short consecutive sequences(length of 913 each).

FHSS Signal Analysis.

New thread started 8 years ago
Hello Dear Forum Users,I am analyzing 2.4Ghz FHSS signal, sampled @40Mhz using USRP.The BW of each hop is 1Mhz.Would like to derive several parameters, based on...

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