problem with matlab function

Started by designengineer77 in comp.dsp14 years ago 4 replies

Hello, I am using a matlab function "vitdec" to simulate viterbi decoding in awgn channel. I noticed a rather weird problem with it. When I...

Hello, I am using a matlab function "vitdec" to simulate viterbi decoding in awgn channel. I noticed a rather weird problem with it. When I increase the msglength the BER improves(eventually plateaus down), my understanding is that BEr improves with the traceback length. Attached is the matlab code and the BERs I observed, traceback length was fixed to 15 for a constraint length of 3. Is the...


how to do bi-lateral Z-transform in Matlab?

Started by kiki in comp.dsp16 years ago 1 reply

Hi all, I wanted to use bi-lateral Z-transform, and esp. I wanted to use Inverse Bilateral Z-transform... But Matlab only provides...

Hi all, I wanted to use bi-lateral Z-transform, and esp. I wanted to use Inverse Bilateral Z-transform... But Matlab only provides Uni-lateral Z-transform and Inverse Transofrm through its "ztrans" and "iztrans" command pair... How to do Bi-lateral Z-transfrom using Matlab? Thanks a lot!


Generating the coefficients for a Xilinx CFIR in Matlab

Started by jmcoreymv in comp.dsp15 years ago

I'm trying to implement a digital down-conversion using the Xilinx DDC core on an FPGA. I have a question about generating the CFIR coefficients...

I'm trying to implement a digital down-conversion using the Xilinx DDC core on an FPGA. I have a question about generating the CFIR coefficients from Matlab when you want a decimation rate of 2 (or more) from the CFIR. Matlab won't allow you to directly generate the coefficients in xilinx format using the command 'coewrite(HCfir)' because it is a multi-rate filter object (not sure what the probl...


FIR filter with initial conditions

Started by orrsarah in comp.dsp7 years ago 9 replies

Hey I am trying to write my own FIR filter in MATLAB for a project I am working on with the aim of eventually porting the project over to c...

Hey I am trying to write my own FIR filter in MATLAB for a project I am working on with the aim of eventually porting the project over to c (so I cannot use MATLAB built-in functions). The filter is taking smaller chunks of a large chunk of data and filtering them separately so I need to be able to set the initial conditions. Has anyone any idea how MATLAB uses the initial conditions, zi, inpu...


can matlab gui do this job

Started by qsu1...@126.com in comp.dsp16 years ago 2 replies

hi ,everyone i want to know if matlab GUI can store and display some data achieved in functions that is, when i execute the GUI , some...

hi ,everyone i want to know if matlab GUI can store and display some data achieved in functions that is, when i execute the GUI , some data is created , then i want some place in the GUI to display the data can matlab GUI do this? thanks


Matlab for Dummies

Started by mimo in comp.dsp17 years ago 3 replies

Hi there, does anybody know, how to call a matlab function outside the current directory, i.e. something like [a,v]=...

Hi there, does anybody know, how to call a matlab function outside the current directory, i.e. something like [a,v]= ..\otherdirectory\function(b,d) Hope to get some help. This message was sent using the Comp.DSP web interface on www.DSPRelated.com


Power value of signal estimated in Spectrum

Started by Anonymous in comp.dsp8 years ago 3 replies

Hi, I was thinking that the peak value observed at the power spectrum for a single tone signal will be the same as its power, but I did not see...

Hi, I was thinking that the peak value observed at the power spectrum for a single tone signal will be the same as its power, but I did not see that when I coded it in matlab when verification. In the matlab code, I was expecting to see the peak power value of -3dB but what I observed is -9dB when using matlab function 'periodogram', and -11.8dB when I later coded the periodogram


RayleighChan in Matlab

Started by Praveen in comp.dsp15 years ago

Hello, I am trying to implement a frequency selective fading channel for a MIMO system. I am using the matlab function RayleighChan in...

Hello, I am trying to implement a frequency selective fading channel for a MIMO system. I am using the matlab function RayleighChan in Matlab. I need to get the channel co-efficients for a given sampling period, time delay, power delay profile, but this function returns only the path gain of the channel. Now, how do I get the channel co-efficients for the system? I really need to kno...


AM demodulation using MATLAB

Started by fara...@gmail.com in comp.dsp15 years ago 2 replies

Hey all, I am having some trouble with AM demodulation using MATLAB. I used the built-in MATLAB function butter to design a low pass filter and...

Hey all, I am having some trouble with AM demodulation using MATLAB. I used the built-in MATLAB function butter to design a low pass filter and using the transfer function obtained, I filtered the modulated signal multiplied by the carrier. Here's the part of my m-file which deals with it: dam=cos(2*pi*250*t).*am; % am=amplitude modulated signal [b,a]=butter(5,250*2*Ts); %designing low pa...


MATLAB Serial Port I/O For Filtering

Started by kerasus in comp.dsp14 years ago 1 reply

Hi guys, I've designed an IIR filter in MATLAB. I used the filter values to write a code for Atmega8. What i used for filter input is the...

Hi guys, I've designed an IIR filter in MATLAB. I used the filter values to write a code for Atmega8. What i used for filter input is the output of a digital sensor. The filter is working pretty good in MATLAB but the filter code for Atmega8 gives a pure sinusoidal output (I couldn't do that if they would ask me to do). I couldn't find the cause of the problem, so I want to filter the output of...


IFFT conversion using FFTW libraries

Started by vivekv80 in comp.dsp14 years ago 4 replies

Hi, I am trying to convert a FFT and IFFT Matlab code to C using the fftw libraries. Hoiwever, I am stuck at a particular step: The Matlab...

Hi, I am trying to convert a FFT and IFFT Matlab code to C using the fftw libraries. Hoiwever, I am stuck at a particular step: The Matlab command is: G = ifftn(P21,'symmetric'); ow do I convert this statement to C using the fftw library. I have tried the following steps: 1.I used fftw_plan_dft_2d to compute the FFT for a double array of size nx by ny. the FFT values match the Matlab values. I...


Modeling DAC in MATLAB

Started by novice_engineer in comp.dsp17 years ago 1 reply

Hi, I am trying to model a 16bit DAC in MATLAB with its nonlinearities and practical impariments. Does anyone have any idea how to do this...

Hi, I am trying to model a 16bit DAC in MATLAB with its nonlinearities and practical impariments. Does anyone have any idea how to do this ? Thanks. Andy This message was sent using the Comp.DSP web interface on www.DSPRelated.com


interp1 command matlab

Started by rosy...@gmail.com in comp.dsp16 years ago 10 replies

Hi Can anybody please describe me how "interp1" command in matlab works on nonuniform data? Does anybody know its algorithm? How can...

Hi Can anybody please describe me how "interp1" command in matlab works on nonuniform data? Does anybody know its algorithm? How can one interpolate complex data on a nonuniform grid to a uniform grid without using matlab's interp1 command directly? Thanks Rose


Run ezdspR2812 board using matlab/simulink. Please help.

Started by doktor2012 in comp.dsp11 years ago 2 replies

Anybody have experiences in programming ezdspR2812 with matlab/simulink? I cannot run my simulink model on the dspR2812 board. Below message pop...

Anybody have experiences in programming ezdspR2812 with matlab/simulink? I cannot run my simulink model on the dspR2812 board. Below message pop when I tried to do that : --------- Error building Real-Time Workshop target for block diagram 'c2812pwmtest'. MATLAB error message: Error using ==> RTW.makertw.callMakeHook at 49 The call to ccslink_ert_make_rtw_hook, during the entry hook generated


IIR for image processing in Matlab. How???? (Plz help)

Started by Anonymous in comp.dsp17 years ago 2 replies

Hello, would any one out there can help me how to appy IIR to filter an 256x256 image using IIR in Matlab? is there any function for it (I...

Hello, would any one out there can help me how to appy IIR to filter an 256x256 image using IIR in Matlab? is there any function for it (I mean 2 D IIR filter). I have to use a IIR filter to filter a image and it is required that I do it in Matlab. I have done it in C and using difference equation: y(m,n)=a1*x(m,n)+a2*y(m-1,n)+..... and everything is fine. Now I have to do it in ...


Same input ,different ans? matlab Vs FFTW

Started by Vincent2046 in comp.dsp16 years ago 2 replies

For learning use of the FFTW, i wrote a sample program,but campared with the result of Matlab,i find the ans are totally different. how can i...

For learning use of the FFTW, i wrote a sample program,but campared with the result of Matlab,i find the ans are totally different. how can i solve this problem ? thank u! i'm looking forward for ur answer. The result of Matlab: a=[1 2 3 1 2 3 1 2]; ans = 15.0000 -1.0000 + 0.5858i -1.0000 + 2.0000i -1.0000 - 3.4142i -1.0000 -1.0000 + 3.4142i -1.0000...


matlab fft and fftw

Started by Marc2050 in comp.dsp10 years ago 8 replies

Hi. I did a simple test (1d fft) of some data with fftw and matlab. The results seem to differ. I wonder what am I missing? I need to port my...

Hi. I did a simple test (1d fft) of some data with fftw and matlab. The results seem to differ. I wonder what am I missing? I need to port my codes from matlab to a custom program. Many thanks for any help. fftw: fftw_complex *in, *out; fftw_plan p; int N = 16; in = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * N); out = (fftw_complex*) fftw_malloc(sizeof(fft...


dsp+matlab

Started by Anonymous in comp.dsp17 years ago 1 reply

hi thats your kindness we want to draw a shape such az circle with external device that connect to computer by parallel or serail port The...

hi thats your kindness we want to draw a shape such az circle with external device that connect to computer by parallel or serail port The only thing that we need is process of shape by matlab & send out of edge position tanks


NN constrained training

Started by Hani in comp.dsp14 years ago 1 reply

Hi all, My question is about the neural network package in MATLAB. I need to train a not-fully connected network, with feedbacks (recurrent)....

Hi all, My question is about the neural network package in MATLAB. I need to train a not-fully connected network, with feedbacks (recurrent). But the main problem is that I need to constrain the weights (e.g. Wi,j=0 or > 0 or


Hilbert-Spectrum in Matlab

Started by joanna in comp.dsp10 years ago 11 replies

Hi everyboby, I'm a matlab newbie and have problems with building a hilbert-spectrum in matlab. Perhaps someone can help me. I have two...

Hi everyboby, I'm a matlab newbie and have problems with building a hilbert-spectrum in matlab. Perhaps someone can help me. I have two vectors: time vector t a the signal vector x. First I compute the analytic signal z(t)=x(t)+i*y(t), where y(t) is the Hilbert Transform of x(t). The polar coordinate form of z with amplitude and phase is: z(t)=amplitude(t)*exp(i*phase(t)). I compute the ...