comp.soft-sys.matlab - The MathWorks calculation and visualization package.
HEllo All, I am having one querry regarding MATLAB. What I would be doing is that I will give the signal from a microphone and I have to use MATLAB so that the signal gets frequency modulated and then I will be taking the output from the headphone jack and mix it with a carrier frequency [Local Oscillator] and send it to the spectrum analyzer.I am doing a project named (Software Radio) where you have to do the signal modulation using Software So could some one help with the code I have written below it is giving the error. ??? Error using ==> + Matrix dimensions must agree.. Regards Nitin The Code is : AI = analoginput('winsound'); addchannel(AI, 1); Fs = 8000;% Sample Rate is 22050 Hz set (AI, 'SampleRate', Fs) d = 10; % 10 second acquisition set(AI, 'SamplesPerTrigger', d*Fs); start (AI); data = getdata(AI); n = Fs* d; pause(5); %plot (data); %sound(data, Fs); % set carrier characteristics Fc = 1000; % carrier frequency (Hz) c = (1:n) / Fs; % carrier data preparation c = 2 * pi * Fc * c; % set modulator Fm = data; % modulator frequency (Hz) mi = 0.5; % modulator index m = (1:n) / Fs; % modulator data preparation m = mi * cos(2 * pi * Fm * m); % sinusoidal modulation % frequency modulation s = sin(c + m); % frequency modulation %sound presentation sound(s, Fs); % sound presentation %pause(d + 0.5); % wating for sound end
Hello, I'm trying to find the frequency response of a laser (20log(power_ amp_out/current_amp_in) that abide to a certain set of rate equations. As an input I'm using a sinusoidal current above threshold, i.e: I=Idc +Im*sin(2*pi*f*T). For this input current I should also be getting a sinusoidal out put. Using the rate equations I get the power vs. time for each input current The question is what time, T, should I use in the input current? Also, since there are some ringing involved in the output power, should I wait for them to settle down? won't it be a problem is higher frequency? Thanks.
Hi, I have a problem in using frequency hopping modulation,I used the blutooth exemple from file exchange but I extract only the modulation and the demodulation part and I resreve the same parameters then the bluetooth exemple but I get this error message : Error reported by S-function 'scomfskdemod' in 'untitled1/Frequency hopping FM Demodulator/M-FSK Demodulator Baseband': Input signal must be discret The channel that I'm using is AWGN. Have any one an idea about this error.
Dear all, We are acquiring the ECG with a high resolution system, sampling frequency 2400Hz. The system is an oversampling sigma delta, 24 bits. In some ECG (from normal subjects and patients) we get, added to the ECG, a frequency modulated version of the ECG itself, e.g. a sinus wave with constant amplitude and whose instant frequency is proportional to the ECG signal value in that particular time instant. This component is not visible in the acquired ECG, and we can see it if we perform some advanced spectral analysis. Moreover the carrier frequency of this component is around 800Hz which looks way to high to be due to some physiological mechanism . Where the hell is this component coming from? Sigma-delta behavior? Interference? (we are doing the acquisition in a shielded room). Your input is welcome. Arnaldo