Hi, I'm starting to learn DSP (Matlab )and I have two questions about it, maybe someone can help me out? I'm trying to measure a frequency from an Audio Device and I'm using FFT to transform it from the time domain to the frequency domain. But I am doing a downsample before the FFT. But you can also do it after the FFT. Do you know what would be the most efficient (before or after)? And why? Another question, I am using zero padding to increase my system resolution (up to 50Hz). My frame length is N=256 and sample frequency fs= 44100 Hz. So 44100/50 = 882, so I need to add 626 zeroes (to 256 frame length) to get 50 Hz resolution, I hope this is correct? I believe this is done for FFT. But is this the same for the DFT? Thank you and regards, --------------------------------------- Posted through http://www.DSPRelated.com >Hi, > >I'm starting to learn DSP (Matlab )and I have two questions about it, >maybe someone can help me out? > >I'm trying to measure a frequency from an Audio Device and I'm using FFT >to transform it from the time domain to the frequency domain. But I am >doing a downsample before the FFT. But you can also do it after the FFT. >Do you know what would be the most efficient (before or after)? And >why? > >Another question, I am using zero padding to increase my system >resolution >(up to 50Hz). My frame length is N%6 and sample frequency fs= 44100 >...

Hello, I was looking at the DVB-H standard which has a serially concatenated encoding with Reed Solomon code (RS(204,188, t=8) from RS(255,239, t=8) ) as the outer code and Convolution code (K=7) as the inner code. At the receiver, I can think of at least four decoding options, 1. Viterbi followed by RS decoder. 2. MAP (BCJR) followed by RS decoder. 3. MAP followed by soft input RS decoder. 4. Having an iterative decoding with MAP and SISO RS as the component codes. I need to answer two questions before I select the decoder. 1. Complexity (DVB-H will be sitting in a handheld device which mak...

accoding to the ETSI EN 300 744 "In the 2K mode, interleaved vectors shall be mapped onto four consecutiv OFDM symbols. For even interleaved vectors these shall start with symbol 0,8,16,24, etc. and for odd interleaved vectors these shall start wit symbols 4,12,20,28, etc. in every super-frame." I have an question about symbol index of 2K mode & in-depth mode. 1. 4 consecutive OFDM symbols index: 0~67,0~67,0~67,0~67. 2. 4 consecutive OFDM symbols index: 0~271. As you know, each index generate different ouput. which one is right? ...

Hi all!! I am performing LS & MMSE channel estimation in an OFDM syste with the DVB-H parameters, where the pilots are not equally spaced as th case with WIMAX. I am facing a severe problem as the BER of both MMSE an LS are identical. I am sure that the LS is correct and that the problem i with MMSE. I've tried everything to make a difference between them. Th only successful attempt was to increase the variance to 100 which i absolutely wrong as it shouldn't exceed 1. Could the problem be with th DVB-H parameters or is there something i'm probably performing incorrectly Please if anyone knows what's the reason behind this or if anyone coul help me deal with this problem, please contact me on m email:mooshi88@gmail.com. I am really tight in time so please help m ASAP!! ...

Hello, there I am studying DVB-H and have these questions. Hope any of you could throw some light on them. 1) If MPE-FEC is used, the receiver would need two RS decoders, RS1(255,191,64) and RS2(204, 188). The result of RS1 is scrambled and fed to RS2. Is my understanding right? 2) With Time Slicing. how is boundary of two adjacent bursts is treated in the outer-interleaver? Will the data at the boundaries of two bursts get mixed up? One receiver only takes one of the burst. how can it sort out the interfering data from adjacent bursts? I didn't find any clause in EN.301.192 indicating each burst is interleaved independently in the outer-interleaver. 3) Spec EN.301.192(2004.06) doesn't explain the Table Boundary and Frame Boundary, etc. I saw them on http://www.decontis.com/DownloadInfo/MPE_FEC.pdf. Do I miss out a specification? 4) MPE and Time Slicing are compulsory in DVB-H, while MPE-FEC shall be made bypass-able, am I right? Thank you! "news reader" <newsreader@google.com> wrote in message news:f2cc5u$sek$1@reader01.singnet.com.sg... > Hello, there > > I am studying DVB-H and have these questions. Hope any of you could > throw some light on them. > > 1) If MPE-FEC is used, the receiver would need two RS decoders, > RS1(255,191,64) and RS2(204, 188). The result of RS1 is scrambled > and fed to RS2. Is my understanding right? > > 2) With Time Slicing. how is boundary of two adjacent bursts is treated >...

Hello, there I am studying DVB-H and have these questions. Hope any of you could throw some light on them. 1) If MPE-FEC is used, the receiver would need two RS decoders, RS1(255,191,64) and RS2(204, 188). The result of RS1 is scrambled and fed to RS2. Is my understanding right? 2) With Time Slicing. how is boundary of two adjacent bursts is treated in the outer-interleaver? Will the data at the boundaries of two bursts get mixed up? One receiver only takes one of the burst. how can it sort out the interfering data from adjacent bursts? I didn't find any clause in EN.301.192 indicating each burst is interleaved independently in the outer-interleaver. 3) Spec EN.301.192(2004.06) doesn't explain the Table Boundary and Frame Boundary, etc. I saw them on http://www.decontis.com/DownloadInfo/MPE_FEC.pdf. Do I miss out a specification? 4) MPE and Time Slicing are compulsory in DVB-H, while MPE-FEC shall be made bypass-able, am I right? Thank you! "news reader" <newsreader@google.com> wrote in message news:f2cc7u$sen$1@reader01.singnet.com.sg... > Hello, there > > I am studying DVB-H and have these questions. Hope any of you could > throw some light on them. > > 1) If MPE-FEC is used, the receiver would need two RS decoders, > RS1(255,191,64) and RS2(204, 188). The result of RS1 is scrambled > and fed to RS2. Is my understanding right? > > 2) With Time Slicing. how is boundary of two adjacent bursts is treated >...

I am studying DVB-T/H/S2 standard, I would like to get source code for the standard codec, both matlab and C. Who can help me ? ...

Hello everyone I have an ODE solver computing the temperature every month during a year this script will do the job for j=1:12 [t,T]= ode45(@monthly_solver,tspan,Tic,[],monthly_heat(j),h2(j),); end where Tic is the intial temperature and J loops represents the months Now the question is about matlab principle and how does it work with the initial condition? i mean as the last temperature of the 1st month is the begining temperture of the 2nd month and the last temp. of the 2nd month is the begining temp. of the 3rd month and so on. Do i need to write a command to do ...

Hi, I have been called for an interview for phd in signal processing from an institute which does research in physics and astronomy. I dont know what to expect. ( I guess they will thorougly grill me). I have done masters majoring in DSP and some years of industry experience. I had done my masters thesis in linear predictive coding of speech and wavelets. The work in the industry was mainly implementation side , video and image compression (H.264,JPEG2000) algorithms on DSPs. Its been quite a while from the last time i had read a text book. I request you to contribute some questions in this thread which could serve as a reference for people in this kind of a situation in general. Also request you to contribute some questions on what to expect in a phd interview other than technical stuff. On May 13, 9:54=A0pm, rajesh <getrajes...@gmail.com> wrote: > Hi, > > =A0 =A0 =A0I have been called for an interview for phd in signal processi= ng > from an institute which does research in physics and astronomy. I dont > know what to expect. ( I guess they will thorougly grill me). > > I have done masters majoring in DSP and some years of industry > experience. I had done my masters thesis in linear predictive coding > of speech and wavelets. > The work in the industry was mainly implementation side , video and > image compression (H.264,JPEG2000) algorithms on DSPs. > > Its been quite a while from the last time i had read a text book...

We are looking for; Software developer with experience in designing and developing DVB-H or DVH-T software. Location : Nederland, Eindhoven Startdate : Asap Duration 12 months You can Phone me Marcel van Bezouw 0031 499 332066 or send a mail m.bezouw@force.nl The Force - IT Professionals BV www.force.nl ...

Hi all, i am using matlab and encountered some problems. Kindly advice. 1)i am using newff function to create a neural network.After which, someone advised me to set some of the parameters ,for example, net.performFcn,net.trainParam.goal and many more. But i tried using my matlab help and search for function to llok up for what these parameters do. However, i can't find any help on these parameters. Where can i find them? 2)i intend to use the train function to train my network. In the train function, according to the help file,we can also give T(network targets) as input. Can someone ki...

Dear all i am student in thesis in communication engineering department and the thesis in 4pam coded and uncoded this program 4 pam uncoded Ralyigh fading the code not run and the matlab not runs and gets this message”Error using ==> modulate at 51 Not enough input arguments.”what can i do in this problem to program run and i need for you if any thing mistakes in the program my email:engkareem.aast@hotmail.com %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% clear all nFFT = 64; % fft size nDSC = 52; % number of data subcarriers nBitPerSym = 52; % number of bits per OFDM symbol (same as the number of subcarriers for BPSK) nSym = 10^4; % number of symbols EbN0dB = [0:10]; % bit to noise ratio EsN0dB = EbN0dB + 10*log10(nDSC/nFFT) + 10*log10(64/80); % converting to symbol to noise ratio % ht=modem.pammod(4); % hr=modem.pamdemod(4); M=4; % Constellation order ht=modem.pammod(‘M’, M); hr=modem.pamdemod(‘M’, M); for ii = 1:length(EbN0dB) % Transmitter ipBit = randi([0 M-1],1,nBitPerSym*nSym) ; % random 1?s and 0?s % % % ipMod = 2*ipBit-1; % BPSK modulation 0 –> -1, 1 –> +1 ipMod = modulate(ht,ipBit); ipMod = reshape(ipMod,nBitPerSym,nSym).’; % grouping into multiple symbolsa % Assigning modulated symbols to subcarriers from [-26 to -1, +1 to +26] xF = [zeros(nSym,6) ipMod(:,[1:nBitPerSym/2]) zeros(nSym,1) ipMod(:,[nBitPerSym/2+1:nBitPerSym]) zeros(nSym,5)] ; % Taking F...

i made a *.m file with de next code q=1.6e-19; Vd=-80; Eo=8.85e-14; E=11.9*Eo; Na=logspace(10,19,20); E_rup_1=20+5*log(Na/1e14)+Na/1e17; E_rup_2=sqrt((-2*q*Na*Vd)/E)*1e-4; semilogx(Na,E_rup_1,Na,E_rup_2) I have ploted in logaritimic scale the functions, "E_rup_1" and "E_rup_2" depending off Na, on the plot and for a Na value, the 2 functions are equal. How can i get the Na value? Thanks If you're trying to graphically determine at which value(s) of Na the two curves are equal, try ginput. HELP GINPUT Kyle beporo wrote: > > > i made a *.m file with de n...

I am a student of engineer, and I am in a course that's call numeric calculus. I have to do a shore an I'm stuck in a question. I have to minimize the error of an aproximation and make a matlab program that do that, just receiving a few points in two dimensions. More clearly, I will receive a table with 20 points, like (x1,y1)(x2,y2)...(x20,y20), and with the method "ortogonal square minimus" (Something like that) I have to minimize the error of an aproximate polynomial. Some clues? I would apreciate a lot any help anyone may do. Thanks. jim In article <4025405.1180395885...

Dear Sir My name is Tusajigwe, student from Brighton University taking MSC in Digital Electronics and Communication. Now am doing a research on Wireless Communication which concern with email alert to GSM users on their cell pohones,what i want from this project is to make GSM users to receive email alert when they have got new mail and this service will be offered by GSM operator ways of achieving 1)To establish link between ISP and SMS centre,because e-mail alert will be in the form of text message and ISP is the one who knows if someone has mail after see it ISP forward to SMS centre by us...

I am still new to Xcode, having come from using CodeWarrior, and am building the CocoaMySQL application from the source to get my feet wet. I'm a little unfamiliar with the layout of the new IDE. The build command in the project file is telling me it can't find the file imported by "#import <SMySQL/SMySQL.h>" -- however, it _is_ able to find "#import <Cocoa/Cocoa.h>". As far as I can tell, both files can be found and viewed in the project, yet neither file is, technically, in the subdirectory specified in the #import directive. E.g., I do have a file named Cocoa.h which Xcode can display in its edit pane, but it's not in any subdirectory named Cocoa, but rather resides in: "/System/Library/Frameworks/Cocoa.framework/Versions/A/Headers/". Similarly, I have a file named SMySQL.h but it's not in a subdirectory named SMySQL but rather in "~/Development/CocoaMySQL source/ SMySQL.framework/Versions/A/Headers/". What I don't understand is why Xcode's #import directive can find one of the .h files but not the other. What's the deal with #imported filenames that contain slashes, and are they literally subdirectories or are they package/frameworks, and what's the convention for them? Where in the IDE can I set the search path for included files and system included files? Van -- Van Bagnol / n p c o m p l e t e at bagnol dot com / c r l at bagnol dot com ....en...

Hi, was wondering if anyone could help. there are a few things i need to know about some Matlab functions 1- if Pwelch and fft are used to find the Spectral Power Density. but how come when u apply them to the same data, the graphs look different? 2- when using the sendmail function, how does Matlab make the connection and send the data? ive looked at the code that Matlab uses for "sendmail" but its very difficult to understand. if anyone could help, i would be really greatful . thanks. ...

Hi all, I'm studying OFDM from documents available from Internet for free and I have some doubts. I understand that guard interval was added to solve problems with multipath-signal delayed. So, because symbol duration in OFDM is long, a little fraction of it can guarantee immunity against long-delayed multipath-signals. So, if I have: .....-------+-------------------------------+-----------.... ..... |GUARD| Nth Symbol |GUARD| .....-------+-------------------------------+-----------.... .........-------+-------------------------------+-----------.... ......... ...

I have been plotted a 3D counter plot via the commands [C,h]=contour3(w,p,green3,10); t = clabel(C,h,'labelspacing',72) get(t(1)) with run the comment in matlab recived this output: Annotation = [ (1 by 1) hg.Annotation array] BackgroundColor = none Color = [0 0 0] DisplayName = EdgeColor = none Editing = off Extent = [0 0 0 0] FontAngle = normal FontName = Helvetica FontSize = [10] FontUnits = points FontWeight = normal HorizontalAlignment = center LineStyle = - LineWidth = [0.5] Margin = [2] Position = [-0.661507 0.649385 -0.01794] Rotation = [290.824] String = -0...

Hello all, I've been following the OFDM demodulation discussions on this NG for some time. However, there are a couple of things that I don't quite understand. Most of the posts I've seen have been regarding baseband demodulation of OFDM signals. My question is, how do you demodulate when the signal isn't at baseband, i.e. its still on an RF carrier?. Can you demodulate the signal directly or would you have to shift down in frequency before you could demodulate?. For arguments sake, lets say we have an 32 carrier OFDM signal with 10Khz tone separation centered on 1Mhz and that signal has been sampled at say, 10M. Could I just shift the carrier frequency down by 1Mhz (plus half the bandwidth of the signal), filter, resample and apply a 32 point FFT to demodulate? Next question is, assuming I end up shifting the carrier down in frequency, what would be the easiest way to do this?. Is there a way to just shift the carrier without mixing it with another signal? Thanks in advance Bill It may be possible to demodulate without basebanding but it would require an unweildy FFT size. In any case it's just not practical. Typically, the first step is to baseband which is a shift in frequency sometimes combined with a hilbert transform to create an analytic signal. One typical wants to shift the center frequency to zero. A shift in the frequency / time domain is equal to a multiplication by a complex exponential in the reciprocal domain. By multiplying the ...

Hi There, Anyone has a OFDM in matlab .m files that could share with me? I need to make some simulations on it and I have been finding lot o problems in building a OFDM in matlab. If someone could send it to me at jpirama@yahoo.com.br would be very nice. If someone has some book that could send me it also would be great. Thanks! Juca P. Souza "Juca P. Souza" <jpirama@yahoo.com.br> wrote in message news:eeeb870.-1@webx.raydaftYaTP... > Hi There, > > Anyone has a OFDM in matlab .m files that could share with me? > > I need to make some simulations on it and I have been finding lot o > problems in building a OFDM in matlab. > > If someone could send it to me at jpirama@yahoo.com.br would be very > nice. > > If someone has some book that could send me it also would be great. > > Thanks! > Juca P. Souza Better yet... keep on building it yourself and post your questions and problems here when you get stuck. You will learn a lot more this way. ...

Hi I am searching a DSP to test a DMT algorithm implementation The goal is to transmit a signal between two boards based on DSP + PPC 8260 Thanks Cheers ...

I have 2 signals with sampling freq 50Hz and different duration. a[n] = [a1 a2 a3 .... an] b[n] = [b1 b2 b3 ............................... bn] In matlab, how to find: A[z]xB[z] A[z]/B[z] Z'(A[z]/B[z]) where Z'() is the inverse Z transform. Thank you! Edw ...

Hello, I have this questions for you. I hope some one can help me. So I have a background image and I want to insert another image over it. A ball for example. But this ball get on top of the background and it streches to full screan. 1) How to make matlab plot a picture in its original size. I don`l want to be stretched. 2) My ball picture is a PNG file so i need not to show the transparent pixels. I used: A = imread('ball.png','BackgroundColor','none'); image(A) but it isn`t working.. 3) Can I load an animation or sound in the plot ...

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