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View output from TI DSP c6713 to oscilloscope

Started by third_person October 14, 2009
Hello

I am using TI DSP c6713 to implement various comm algos, at my univ. and
want to view the output on oscilloscope. Can any one guide me?

Details: 

I am using Simulink to design a simple BPSK modulator and am using the
link to Code Composer Studio to build the model as a CSS project.
Afterwards I am running it.

I now want to verify if the output is indeed BPSK modulated symbols by
visualizing the constellation diagram on an oscilloscope. So, the output
I've sent to the Serial output channel,and connect the probes of the
oscilloscope


So,

1) can I actually view the modulation on the oscilloscope since it is only
complex baseband?

2) Extending this question further, if we create an OFDM transmitter,
would I be able to view the spectrum in frequency domain, even if the input
is complex baseband?


Thanks


>1) can I actually view the modulation on the oscilloscope since it is
only
>complex baseband?
Yes you'll be able to view a constellation with a scope operating in XY mode if you apply inphase and quadrature channel outputs to its X and Y inputs and synchronize it to the data clock.
>2) Extending this question further, if we create an OFDM transmitter, >would I be able to view the spectrum in frequency domain, even if the
input
>is complex baseband?
If you are using some advanced DSO or a PC-based scope then it's software probably supports this function. Actually, i have never met a scope that would be able to do this. -- Alexander
>>1) can I actually view the modulation on the oscilloscope since it is >only >>complex baseband? > >Yes you'll be able to view a constellation with a scope operating in XY >mode if you apply inphase and quadrature channel outputs to its X and Y >inputs and synchronize it to the data clock. > >>2) Extending this question further, if we create an OFDM transmitter, >>would I be able to view the spectrum in frequency domain, even if the >input >>is complex baseband? > >If you are using some advanced DSO or a PC-based scope then it's
software
>probably supports this function. Actually, i have never met a scope that >would be able to do this. > >-- >Alexander >
Thanks Alexander. The complex baseband output can viewed by the oscillope's XY plot, I agree, but how I am going to separate the "inphase" and "quadrature" component from the output port of c6713? Secondly, do you know any method with which I can up convert complex baseband symbols to view the spectrum on a spectrum analyzer. I have access to Rohde Schwartz RF generators. I don't have expert knowledge of upconversion in this manner, if it is possible Others, please help me too, by sharing information
>The complex baseband output can viewed by the oscillope's XY plot, I >agree, but how I am going to separate the "inphase" and "quadrature" >component from the output port of c6713?
What board do you use and what is connected to the DSP serial port?
>Secondly, do you know any method with which I can up convert complex >baseband symbols to view the spectrum on a spectrum analyzer. I have
access
>to Rohde Schwartz RF generators. I don't have expert knowledge of >upconversion in this manner, if it is possible
Some modern waveform generators have a built-in IQ modulator with analog I/Q inputs (sometimes it comes as an option which is purchased separately). I guess that R&S has such generators too. You will have better chances to get the information if you call or write to their support service. -- Alexander
>>The complex baseband output can viewed by the oscillope's XY plot, I >>agree, but how I am going to separate the "inphase" and "quadrature" >>component from the output port of c6713? > >What board do you use and what is connected to the DSP serial port? > >>Secondly, do you know any method with which I can up convert complex >>baseband symbols to view the spectrum on a spectrum analyzer. I have >access >>to Rohde Schwartz RF generators. I don't have expert knowledge of >>upconversion in this manner, if it is possible > >Some modern waveform generators have a built-in IQ modulator with analog >I/Q inputs (sometimes it comes as an option which is purchased
separately).
>I guess that R&S has such generators too. You will have better chances
to
>get the information if you call or write to their support service. > >-- >Alexander >
I'm using a Texas Instruments 320TMSC6713 DSK If you have any paper regarding it, I'll be thankful
>I'm using a Texas Instruments 320TMSC6713 DSK
I have never worked with this board, but as i can see from its block diagram the serial port is connected to a stereo codec. So you can transfer inphase and quadrature samples to its left and right channels, correspondingly. The analog output of the codec is available through a 3.5 stereo connector. In order to connect the scope you can make a cable with stereo jack on one side and two BNC plugs on the other or buy a stereo jack-2xRCA socket adapter, two RCA-RCA cables and two RCA socket-BNC plug adapters (maybe you'll find a better combination). The only problem is how to obtain bit synchronization signal. Actually serial port frame synchronization signal should be used for synchronization of the constellation diagram but i can't say whether it is available at the expansion header or not without the schematic of the board.
>If you have any paper regarding it, I'll be thankful
This book might be useful http://www.amazon.com/Digital-Processing-Applications-TMS320C6713-TMS320C6416/dp/0470138661 -- Alexander