Where's source code, DSP implementation, & documentation for CVSD vocoder? (16kbps Continuously Variable Slope Delta Modulation military standard)

Where's source code, DSP implementation, & documentation for CVSD vocoder? (16kbps Continuously Variable Slope Delta Modulation military standard)

Hi I am using QPSK Modulation. Say the data rate be 'Rb' and the carrier frequency is 'fc'. I believe to perform carrier synchronisation...

Hi I am using QPSK Modulation. Say the data rate be 'Rb' and the carrier frequency is 'fc'. I believe to perform carrier synchronisation at the receiver, we need to also have the carrier component in the received signal. How do we achieve this? Thanks in advance Bye

Hello, I am studying MSK modulation, does anyone know how to genrate a MSK signal in matlab, pls help me..Thanks. Gon.

Hello, I am studying MSK modulation, does anyone know how to genrate a MSK signal in matlab, pls help me..Thanks. Gon.

Please tell me which is a reliable modulation to use in CATV system, QPSK or QAM? What are the advantages and disadvantages. Please discuss it in...

Please tell me which is a reliable modulation to use in CATV system, QPSK or QAM? What are the advantages and disadvantages. Please discuss it in a "lay man's term" and set some examples. Thank you and more power.

Hello People I need some help in understanding and implementing Digital FM -Modulation and Demodulation using digital signal...

Hello People I need some help in understanding and implementing Digital FM -Modulation and Demodulation using digital signal processing techniques. References to related links is required. or If you have any papers related to this topic- please email it to parth175@yahoo.co.in Thanks in advance Bye Parthasarathy

Hi All, 1) I want to implement MODEM with 128Kbps at 100Khz with high doppler shift channel. Which modulation technique would be suitable...

Hi All, 1) I want to implement MODEM with 128Kbps at 100Khz with high doppler shift channel. Which modulation technique would be suitable . Whether I can go with OFDM or SC-FDMA? Any suggestions 2) Is it possible to simulate 128Kbps with Matlab Thanks & Regards, Ammankumar.S

Hello All, As an additional question . I am just confused in terms of detecting errors , Can anyone please tell which modulation scheme ...

Hello All, As an additional question . I am just confused in terms of detecting errors , Can anyone please tell which modulation scheme 16-QPSK or 64 QAM would be easy to detect errors and where does the basic criteria lies. Thanks in Advance Syed

I've been looking at making an FM demodulator for a software defined radio. In principle at least this is trivial if you have a complex signal...

I've been looking at making an FM demodulator for a software defined radio. In principle at least this is trivial if you have a complex signal (I and Q), as you can compute the phase (atan(Q/I), then the modulation amplitude is just the derivative of phase with time. As far as I can see, this is should trivially easy, though the lack of arctan function might be the stumbling block on a fixed ...

I was trying to design a bandlimited pseudorandom signal with constant envelope for radar/sonar and like applications. I.e. frequency...

I was trying to design a bandlimited pseudorandom signal with constant envelope for radar/sonar and like applications. I.e. frequency modulation with smoothed transitions. The problem is closely related to CPM for data transmission, however the optimization criteria are not quite the same. In particular, it turns out that optimal value for normalized deviation is higher then 0.5, optim...

Is it sensible to say that qudrature conversion can be applied to any signal, and the product of the conversion is an I/Q pair that represent...

Is it sensible to say that qudrature conversion can be applied to any signal, and the product of the conversion is an I/Q pair that represent the inputs signal? Thanks, Ben

Hello, Im at yet another DSP challenge ... Im trying to implement a simple software modem to transmit 4kbps over a 3Khz radio channel. Any...

Hello, Im at yet another DSP challenge ... Im trying to implement a simple software modem to transmit 4kbps over a 3Khz radio channel. Any suggestions on what the absolute simplest form of digital modulation to be used? Thanks! --Shafik Amin

Hi, i'm an undergraduate student doing some project on Stochastic Processes and i have a few questions on OFDM. There are few things that i...

Hi, i'm an undergraduate student doing some project on Stochastic Processes and i have a few questions on OFDM. There are few things that i don't quite understand and they are mainly in Digital Signal Processing domain (that is not my field of expertise). I'm writing code in MATLAB for transmitting data using sound and use OFDM modulation. Mathematically the transmitted multicarrier ...

Hello everybody, I am beginning on this communication stuff and I have some doubts I´d like to clarify. One of them is regarding I/Q structure...

Hello everybody, I am beginning on this communication stuff and I have some doubts I´d like to clarify. One of them is regarding I/Q structure for transmitting and receiving a signal. I´d like to someone to tell me if I am right on the following: - Two signals are generated in the transmitter with an specificic modulation (BPSK, QPSK...), and multiplied by a cosine and a sine (Inphase-Quad...

Take a normal analogue FM radio system (like the ones in a car). Now FM is defined as cos(Wct + k integral( f (t) dt ) ) and PM...

Take a normal analogue FM radio system (like the ones in a car). Now FM is defined as cos(Wct + k integral( f (t) dt ) ) and PM as cos(Wct + kf(t) ) Where f(t) is the signal. where k is a constant depending on the depth of modulation etc. Now it is known that broadcast 'FM' uses pre-emphasis at the transmitter (a 6dB/octave slope with break-frequencies of say 1kHz to 15kHz ...

Hello Everyone, My name is Rohith and I recently started working on OFDM. I am trying to simulate 4 carrier OFDM system using QPSK...

Hello Everyone, My name is Rohith and I recently started working on OFDM. I am trying to simulate 4 carrier OFDM system using QPSK modulation. I am not sure if my current test model is correct or not. Could you please review this and let me know if I am doing anything wrong? Here is the link to my simulink model: http://rohithramnath.googlepages.com/home Thank you so much. Re...

Hi, I am designing an 802.11b transceiver and after developing the block of modulators and scrambler I have a question: these ones (blocks)...

Hi, I am designing an 802.11b transceiver and after developing the block of modulators and scrambler I have a question: these ones (blocks) have control inputs which must be used to control their functionality ... How can I control them? : There are three parts on the frame: preamble, header and data ... and each one can be transmitted with different modulation so ... how can t...

I'm evaluating receiver structures for the ETSI DMR spec, but not having much luck finding any work in this area. They use continuous...

I'm evaluating receiver structures for the ETSI DMR spec, but not having much luck finding any work in this area. They use continuous phase modulation, so I anticipate I'll have to use a viterbi demodulator to get it done. Unfortunately they choose h=.27, so I have at least 200 states, times whatever number of symbol cycles their pulse shape is over (not clear on this, three maybe?). So I'm loo...

Hello, I am trying to demodulate a binary CPFSK with modulation index of 0.6 With correlation receiver & viterbi decoder I am able to...

Hello, I am trying to demodulate a binary CPFSK with modulation index of 0.6 With correlation receiver & viterbi decoder I am able to demodulate a synchronized signal, but i am stuck with synchronization techniques. Can anyone please let me know any ideas for synchronization. Thanks & Regards, Ajith

On Tuesday, January 25, 2011 9:35:52 AM UTC-5, Clay wrote: ... > Cool that you built one. Did you use it to measure distances? No. I...

On Tuesday, January 25, 2011 9:35:52 AM UTC-5, Clay wrote: ... > Cool that you built one. Did you use it to measure distances? No. I tried to burn holes. All I succeeded in doing was cracking lenses. By placing the spark gap toward one end of the metalized Teflon, I wasted little energy in the backward direction. Jerry

Hi everyone, say that we have a signal of this kind x(t) = A*cos(2*pi*f*t + B*y(t)); say that f is 1 kHz. If y(t) has a low frequency...

Hi everyone, say that we have a signal of this kind x(t) = A*cos(2*pi*f*t + B*y(t)); say that f is 1 kHz. If y(t) has a low frequency content compared to the carrier frequency, I find that it easy to extract the B*y(t) signal either using quadrature demodulation or the Hilbert transform. However, in the case where y(t) has a high bandwidth, for example a wideband signal with frequen...