modulator in software defined radion

[Altera_Forum]

dear all, 

 i'm currently doing a project for designing a modulator in software defined radio communication system. i was told by my supervisor to do it in fpga, but it seem i dont have any idea on how to start it. if any one of you out there can help me please... i just need the kick start because i'm currently, totally blank...

[Altera_Forum]

You should probably start out by determining what sort of modulation scheme you need to implement in the radio.  

 I'm designing a demodulator in an FPGA for a pretty simple FSK signal, using the same techniques one would use in hardware (individual filters for each frequency of interest, a low pass filter and a voting system to determine each symbol).

[Altera_Forum]

i'm designing a universal modulator for all type of modulation.

[Altera_Forum]

I'm implementing a modulador on FPGA ( Amplitude Modulation), I think that you have to define a kind of modulation, "UNIVERSAL MODULATOR" is a very general idea.

[Altera_Forum]

it is for the digital modulation. ALL TYPE OF IT. the main idea of the project is to be able to modulate any kind of digital signal.

[Altera_Forum]

I'm not sure how one would start defining a "universal modulator". Maybe you could approach this in sections - create an FM block, and AM block, etc, and then bolt them all together in a selectable manner. 

 Can you describe how you would create a "universal modulator" in discrete hardware? That might give a better understanding of how to approach the design.  Or perhaps you could start defining the system by the inputs and outputs - for example you might want to take an audio signal input and get a 16 QAM output.     --

[Altera_Forum]

The design also depends on the intended output interface: baseband driving external dedicated I/Q modulator hardware (e. g. an AD9773 DAC), I/Q IF or carrier frequency?

[Altera_Forum]

it should be in I/Q IF because i'm doing the digital modulation for PSK, FSK, ASK, APK, QPSK, and others that have to do in digital communication.

[Altera_Forum]

--- Quote Start ---  I'm not sure how one would start defining a "universal modulator". Maybe you could approach this in sections - create an FM block, and AM block, etc, and then bolt them all together in a selectable manner. --  --- Quote End ---   maybe i can try this on Matlab simulink first. if it can be done.     --- Quote Start ---  Can you describe how you would create a "universal modulator" in discrete hardware? That might give a better understanding of how to approach the design. --  --- Quote End ---    i'm not pretty sure yet. thats why i started this thread so maybe any one here can share their opinions with me. i'm pretty blank my self because i'm still new in FPGAs area and my supervisor doesnt help me to understand it well.    --- Quote Start ---  Or perhaps you could start defining the system by the inputs and outputs - for example you might want to take an audio signal input and get a 16 QAM output.     --  --- Quote End ---    hurm well... to tell you the truth, i havent been given a complete information about the project by my supervisor. when i ask, he only told me to do it for all type of digital modulation and i'm not pretty sure what he's trying to tell me.   sorry for the lack of information.

[Altera_Forum]

--- Quote Start ---  maybe i can try this on Matlab simulink first. if it can be done.   --- Quote End ---   Yes, that would be another approach. If you have DSP Builder as well as Matlab/Simulink, I believe there is a mechanism to create VHDL code directly from the DSP Builder project. I'm not well educated in this approach, however.  dsp builder design example from altera's website (http://www.altera.com/support/examples/dsp-builder/exm-dsp-builder.html)    --- Quote Start ---   hurm well... to tell you the truth, i havent been given a complete information about the project by my supervisor. when i ask, he only told me to do it for all type of digital modulation and i'm not pretty sure what he's trying to tell me.   sorry for the lack of information.  --- Quote End ---    Without a little more detail from your supervisor, this project can become unwieldy very quickly. Perhaps you can focus on the end product - are you designing a modulator for a particular industry or a particular product line? Your company should have some documentation on what modulation schemes you currently use.  As an example, the Agilent signal generator on my desk can create all sorts of modulation schemes, but even that is limited when you start finding some of the more specialized ones.  Maybe you should start with one or two of the more simple modulation schemes - PSK, FSK, ASK, and build those pieces. Do you know how to generate the modulators to begin with?   Another approch would be to purchase IP that already does what it is you are attempting to do (once your supervisor defines this better for you).  Here is some IP from the Altera Website: modulators & demodultaors (http://www.altera.com/products/ip/dsp/modulation_demodulation/ipm-index.jsp?gsa_pos=1&wt.oss_r=1&wt.oss=modulation)   Try plugging in some keywords into the Altera.com search function and see what comes out & if it applies to your situation. You can also give your FAE a call and see what they have to offer (maybe a good approach if you need an Non-disclosure that you cannot get on a public forum)  Hope this helps some. --