System Sensitivity based on Power Spectral Density

Started by ?ine Canby in comp.dsp15 years ago 3 replies

Hi all, I hope you can help me with this problem because I'm really confused by it at this stage. I have implemented a demodulation scheme...

Hi all, I hope you can help me with this problem because I'm really confused by it at this stage. I have implemented a demodulation scheme on a dsp processor and I'm currently trying to establish the sensitivity in terms of radians per root Hz. The signal before demodulation is - cos(cos(2*PI*8kHz*t) + s(t)) The demodulated signal is of the form - s(t) The signal prior to d...


Software Pulse Amplitude Demodulation

Started by berriferous in comp.dsp14 years ago 2 replies

Hi all, I am doing a simple demodulation of a sampled RF signal. I set my digitizer at a fixed 1 GS/s. I don't know what my carrier will be,...

Hi all, I am doing a simple demodulation of a sampled RF signal. I set my digitizer at a fixed 1 GS/s. I don't know what my carrier will be, but it will be less that 200MHz. The signal is pulse amplitude modulated, and I want to recover the original signal. To do this, I have applied a Hilbert transform, and then derived the magnitude which gives me a good approximation of the encoded signa...


how much dopler effect are DVB-T receivers on the market conquer?

Started by daor in comp.dsp12 years ago 3 replies

how many people are here designing the DVB-T demodulation ASIC? I am very interested in the performance of DVB-T receivers on the market or to...

how many people are here designing the DVB-T demodulation ASIC? I am very interested in the performance of DVB-T receivers on the market or to be on the market,and i would like to discuss the OFDM demodulation technology here with you. 3x!


how much doppler effect are DVB-T receivers on the market able to conquer?

Started by daor in comp.dsp13 years ago

how many people are here designing the DVB-T demodulation ASIC? I am very interested in the performance of DVB-T receivers on the market or to...

how many people are here designing the DVB-T demodulation ASIC? I am very interested in the performance of DVB-T receivers on the market or to be on the market,and i would like to discuss the OFDM demodulation technology here with you.


msk demodulation

Started by harsh17 in comp.dsp14 years ago 5 replies

Hi evrybdy, I am new to this grp.I am working on a project involving demodulation of msk signals.The transmitter has been...

Hi evrybdy, I am new to this grp.I am working on a project involving demodulation of msk signals.The transmitter has been implemented using a AD9851 DDS chip.The transmitter switches between 16MHz and 24MHz depending on the incoming bits.At the receiver,I am using AD6620 to downconvert the signal to baseband and then AD6640 A to D converter digitizes the signal.I intend to do the bas...


FSK Modulation/ demodulation

Started by Somia in comp.dsp14 years ago 2 replies

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am...

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am trying to do FSK demodulation in software. I'll record that data in a wave file and then analyise it. i dont have any signal processing background and i am stuck in this problem. please help according to the standard: Mark is represented by 1300Hz, ...


FSK Modulation/ demodulation

Started by Somia in comp.dsp14 years ago 1 reply

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am...

Hi I have to communicate with telephone which is sending us data that is in voice band and FSK modulated. I dont have an fsk modem so i am trying to do FSK demodulation in software. I'll record that data in a wave file and then analyise it. i dont have any signal processing background and i am stuck in this problem. please help according to the standard: Mark is represented by 1300Hz, ...


Digital FM demodulation

Started by Anonymous in comp.dsp13 years ago 4 replies

hello, I'm designing a receiver for FM demodulation and I have a little problem with the filters of the downconverter. Here's my...

hello, I'm designing a receiver for FM demodulation and I have a little problem with the filters of the downconverter. Here's my specifications : FM carrier 10,7 MHz, 20 kHz deviation. I send to the modulator a 19.2 kHz sinus signal. At the receiver, I first band-pass filter the carrier : center to 10,7 MHz with 80 kHz bandwidth. Then I undersample at 4 MS/s : so I have got a first ...


Single Side Band (SSB) Demodulation

Started by bangash in comp.dsp12 years ago 8 replies

Hello Every One! Actually I am working on Single Side Band (SSB) Modulation/Demodulation. I have successfull programmed the Modulator...

Hello Every One! Actually I am working on Single Side Band (SSB) Modulation/Demodulation. I have successfull programmed the Modulator and the Demodulator. But Now I have one problem, that I want extract the Carrier Frequency from the SSB (transmitted) signal at the receiver end. Any one can guide my in the respect. Thanks.......................... ____________________________________...


SNR DSSS WCDMA

Started by Anonymous in comp.dsp13 years ago

hi everybody, Did you know if the SNR (to compute the BER vs SNr) is compute after or before the complex demodulation DQPSK (Dot and Cross)...

hi everybody, Did you know if the SNR (to compute the BER vs SNr) is compute after or before the complex demodulation DQPSK (Dot and Cross) ? After the demodulation, we integrate the signal (Dot and Cross) and then we make the symbol decision ? Thanks


Timing recovery design in PSK demodulation

Started by gobruins in comp.dsp10 years ago 5 replies

Hi, We are building a multichannel Q/8PSK demodulation system, we have completed the carrier recovery design, and in the process of designing...

Hi, We are building a multichannel Q/8PSK demodulation system, we have completed the carrier recovery design, and in the process of designing a timing recovery loop to build a stable symbol clock. We have a coarse idea how to do it, but would like to verify the feasibility. The block diagram of our design is 187.5Msps 4R 4R A/D ---------->


RTTY (AFSK) demodulation

Started by sven98de in comp.dsp9 years ago 14 replies

Hi, has somebody here implemented a RTTY (AFSK) decoder. Any suggestions how to proceed ? I've found some technical abstracts about FSK...

Hi, has somebody here implemented a RTTY (AFSK) decoder. Any suggestions how to proceed ? I've found some technical abstracts about FSK demodulation in the WEB like: - frequency discriminator with IIR resonator - frequency discriminator with FIR bandpass filter - digital PLL Any idea how complex it is to implement one of these methods ? What processor is sufficient for this, does a microc...


I/Q data scaling before AM/FM demodulation

Started by engrmasood2002 in comp.dsp5 years ago 7 replies

Hi All, I have demodulated two AM files (I/Q) succesfully but for one of the I/Q files which was Gnuradio (USRP) file i had to scale down I and Q...

Hi All, I have demodulated two AM files (I/Q) succesfully but for one of the I/Q files which was Gnuradio (USRP) file i had to scale down I and Q components before demodulation by multiplying by 0.0001 (experimental value) to get the value that can be demodulated and heard on the PC speakers. The values read from file were like these I= 469.00000, Q=-273.0000, I=472.00000, Q=-263.0000,,,,,,,,,,...


Convert demodulation I/Q to soft Data

Started by Robert in comp.dsp14 years ago 11 replies

I found the signal after demodulation module are Data_I[q:0] and Data_Q[q:0]. How to convert Data_I[q:0] and Data_Q[q:0] to soft...

I found the signal after demodulation module are Data_I[q:0] and Data_Q[q:0]. How to convert Data_I[q:0] and Data_Q[q:0] to soft information Data[q:0]? May you please recommend some references? Any suggestions will be appreciated! Best regards, Robert


Costas Loop for coherent demodulation of GMSK

Started by Sonali Agarwal in comp.dsp9 years ago 7 replies

Hello, i want do do carrier recovery using costas loop(BPSK based) for coherent demodulation of GMSK. Has anybody tried it? If yes,...

Hello, i want do do carrier recovery using costas loop(BPSK based) for coherent demodulation of GMSK. Has anybody tried it? If yes, please help me out. Thanks and Regards, Sonali


Question on AM demodulation...

Started by Andre in comp.dsp5 years ago 45 replies

Hi all, I am a bit stuck in a demodulation thing. Lets say I have a system that generates an AM signal and wants to detect distorsions of...

Hi all, I am a bit stuck in a demodulation thing. Lets say I have a system that generates an AM signal and wants to detect distorsions of the LF signal after feeding the AM modulated signal through a potentially nonlinear system. This means I have phase locked TX and RX. Lets say I modulate a signal at f0 with sine at f1 with 100% modulation: signal = sin(w0*t) * (0.5 + 0.5 * sin...


Change center frequency of I, Q values

Started by Raphael31 in comp.dsp13 years ago 2 replies

Hi All, I use a samplig card with DDC(Digital Down Conversion with quadrature mixer and filter to eliminate frequency at 2*fc) that provides...

Hi All, I use a samplig card with DDC(Digital Down Conversion with quadrature mixer and filter to eliminate frequency at 2*fc) that provides me directly I, Q values of the signal. As the demodulation is performed offline, with the recorded point, the values are not centered around the carrier of interest. I need to track the center frequency of the carrier during the demodulation to compe...


MSK Demodulator

Started by Tim Wescott in comp.dsp14 years ago 2 replies

I've seen a number of inquiries about minimum shift keying, it's generation and demodulation. I haven't been able to find anything to...

I've seen a number of inquiries about minimum shift keying, it's generation and demodulation. I haven't been able to find anything to recommend on the web, which is frustrating since I built a MSK receiver for my Master's thesis about 15 years ago. So I've posted my Master's thesis. It goes into some detail about MSK, it's generation and demodulation. It also goes into some detail ab...


OFDM demodulation question

Started by Harry in comp.dsp13 years ago 4 replies

Here's my question: In doing the OFDM (like DVB-T) demodulation, why do people just talk about carrier frequency sync and carrier phase noise...

Here's my question: In doing the OFDM (like DVB-T) demodulation, why do people just talk about carrier frequency sync and carrier phase noise but not carrier phase itself? Does that mean OFDM is not coherently demodulated? Thank you for your help! -- Harry


AM SSB demodulation

Started by Vikram Chandrasekhar in comp.dsp15 years ago 12 replies

Hello, I am trying to demodulate an AM SSB (single side band) baseband signal. Are there any standard techniques/papers for AM SSB...

Hello, I am trying to demodulate an AM SSB (single side band) baseband signal. Are there any standard techniques/papers for AM SSB baseband demodulation in the presence of arbitrary phase/frequency offsets? To elaborate my query, let s(t)={m(t)+j*H[m(t)]}*e^(j*2*pi*fc*t) where H[ ] denotes the Hilbert transform, fc denotes the carrier frequency and s(t) is the complex analytic signal be ...