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TMS320C6748: Picking best transciever option for closest-to-SDR approach on C6748

Part Number: TMS320C6748
Other Parts Discussed in Thread: CC2500, CC1125, CC1200, CC1310

Good Afternoon everyone,

I'm going to be working soon with C6748  DSP, however, eventually I would like to transmit data wirelessly and I want the closest-to-SDR pick since it is for academic purposes, I want to insert by myself the preamble of the frame with the length that i want, as the sync word, etc. I would like students to see what happens if there a bad preamble and no Bit Sync is achieved, what happens if, lets say, sync word is all zeros. As you see, it is highly configurable, and most of transcievers are very configurable but are fixed in some aspects. For example CC2500 has address capability but it has a fixed length field of 1 Byte. What if i want to use less bits? Or the fact that preamble is 8 x n bits long. That is good, but is not what i'm looking for. 

I'm kind of new at this, then I would like to know any suggestions about this,

So far I've checked CC family, like CC1125 or CC2500 which are very configurable, but are not that close to SDR. 

Another option is to independently buy modulator/demodulators, ADC, DAC, etc, and implement this on my own but it would requiere lot of time on testing, connecting, caring about circuitry for votages regulations/compensations and looking for most compatible technologies; which is really time consuming. I want to be somewhere between SDR flexibility and SoC facility. What can I pick? 

I need a modem that basically limits itself to only transmit what I write in baseband.

I'm taking advices, suggestions, warnings and well wishes.

Thank you so much for your time in advance.

  • I'm not fully understanding your spec.

    The modem is different from RF chip to RF chip. The available settings for sync word, preamble etc are therefore more or less limited to what you will be able to receive with that radio. Meaning that playing with random sync word lengths etc in many cases will just cause that you don't receive anything or get a lot of false syncs. Our radios are built to be flexible but within some limits to increase the probability for good RF performance.
  • Yes, that's the intention, to show students what happen if the sync word is wrong, if they get false sync, they should be able to explain why. That's the purpose. 

    Is there any transciever that helps me with this? 
    (In the figure says 'modem', instead, transceiver is more appropiate).

    Thanks for you answer!

    Have a good day!

  • Maybe CC1200 since you can do strict sync on the full sync word on this device. From a student point of view to show the basics on the phy level this device could be good since it's easy to play with the registers and set a pin high if you receive a valid packet.

    If the intent was to show one level up CC1310 could be a better choice. But some of the low level details are more hidden for the user on this device which is a minus if the purpose is to learn about basic RF.
  • I Appreaciate your answer. It is a good option. On the other hand, what options do we have to make this? 

    That would be 2 components (asumming that one of them includes inside multiple stages), and could do exactly what I want. 

    I know may be a bit confusing why taking a longer road if could take the simpler one, but tell me. What components are needed to complete this solution?

  • I don't have an overview over this part of our offering but if you start looking here: www.ti.com/.../overview.html you should be able to find some possible solutions.
  • Thanks for your answer. Looking on that link, and googling for SDR results I found this:

    www.ti.com/.../sprt434a.pdf
    www.ti.com/.../endequipmentproductfolder.tsp

    Searching about that, it says that is obsolote and no longer available, i wanted to know if there is any similar modern version of that product. It says it is available from 3rd party Lyrtech but if TI has a more actual version of the product I'd go after that one.
  • It looked like from your last figure that you were looking for mixers, DACs etc and hence you should search for each part in a RF context and not search directly for SDR.
  • Well, in that case, would this work? 

    I don't know what filters to utilize because i'd need them to be adjustable. We would be working mostly in Narrow Band 

  • I believe you should at least include separate PA and LNAs. I have only worked with RF on chip so I haven't looked into what would be required to build up a complete radio with building blocks.

    This starts to be fairly complex. This would require that most of the settings in the system is fixed before students are starting to work with it and the model implementation in the DSP also require some work.