Paolo Martinetti (@PMartin)
Thank you Cedron. My file is Mono mode. It is very interesting what you say.The problem i think is endianity. Wav data is stored in little endian format and my...
Hi Benoit,thanks a lot for your suggestions.For example, i haven't considered the data endianity, but i created a tone signal (1Khz sine wave) and it is emitted...
Hi, on my c5505 eZdsp i have configured the codec at 192 Khz recording / playback frequency.I'd like to reproduce a 8 Khz wav file, saved in 16 bit PCM format...
Thanks, but I think i'll first try the analytic signal strategy. I think it is more efficientRegardsPMartin
DSB-SC demodulation in real time is not so simple because you don't know the phase of the carrier of the received signal.RegardsPMartin
Hi,my sampling rate is 192 Khz.I have to demodulate a DSBSC signal with carrier 32768 Hz.I want to use FFT because my SOC has a built-in FFT Hw accelerator.I have...
Thanks.I'm a newby...could you provide an example?I'd like to demodulate only one band, not bothThanksPMartin
Hi,i'd like to shift the frequency of a signal that is modulated DSBSCThe problem is that the I FFT the signal, but the carrier frequency is not integer multiple...
Hi David, solved:sum and products in iSin and iCos overflowed:Here's the solution:Int16 iSin(Int16 angle){
Int16 cc; // cosine course
Int16 cf; //...
Hi David, there is something wrong in my implementation. I'd like to ear your opinion, please.I tested the algo calculating sine and cosine of 5/6*pi.If 2*pi =...
Yes, a lot is gained from sums and multiplications too...apart the fact of overflows and underflows said before...
Yes,6000 cycles is an important gain. I gain them in a 384 loop, so i gain, at 120 Mhz about 19 msec only by sine and cosine.Thanks a lotPMartin
Hi David,i've implemented sin and cos and i gained 6000 cycles!I need to exercise in Fixed Point arithmetic to proceed...I have overflows and underflows in my algorithm,...
Very clear.Obviously, i must use fltoq15 of DSPLIB to convert of the course and fine tables to Q15 format.Now, how can i apply sin(a+b) = sin(a)cos(b) + sin(b)cos(a),...
David, i have some questions:"Calculate a table for the sin(a) and cos(a) (remembering that cos(a) = sin(a+pi/2)), where "a" is the upper 8 bits of the angle. ...
David, you are very very helpful!I'll try to implement then i'll make you to knowThanks you so much!PMartin
Thanks David,I'm passing from fp to 32 bit integer operations.How can i convert a float into Q31?Reasoning it should be:Q31 = float * 2^31, so Q31 = float <<...
Hi David,I measured a lot of time spent in cos(), sin() and atan2.Furthermore, I'm implementing my algo with float data, instead of using integers. Being a newby...
Yes, I done, but the time gain is not enough.I decided to maintain an input queue and an output queue.When there is a new frame in the input queue, i process it.Then...
If i create a receive buffer, long enough, and elaborate then transmit,i'll transmit with 45 msec delayed, and this isn't a problem. Agree?
Hi,I implemented a dsbsc demodulator using 2nd order costas loop on SoC c5505 eZdsp.My demodulation functions takes about 45 msec of cpu time, while data arrive...
Ok, but if i multiply a real signal by a complex signal i obtain a complex signal....so how can i get the demodulated real signal
dudelsound, i thank you a lot. I'm totally out of road.I'm developing Costas loop in order to demodulate my signalThanks you so muchRegards,Paolo
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