Can I implement MIMO-OFDM Communiation system using C6713? Need urgent reply....

This is a very difficult question to answer. Even if you had all the specifications included in the posting above, this is a large engineering task that you are undertaking. It must be sketched out from the system point-of-view to determine what operations must be done to implement this communications system.

I could easily say that, yes, the C6713 and AIC23 can be used to implement a system as you have described it. But you might want it to work at frequencies higher than these can handle, or you might have communication protocols to handle that will over-burden the DSP.

Only you will be able to answer these questions, after a full engineering analysis of the job you want to do.

Thanks alot RandyP for your nice response.

Yes, you are right. This is a large engineering task. I am trying my level best to complete this task but AIC23 is not supporting this task.

I have been working on AIC23 for last 2 months. I am trying to send 2 OFDM symbols from AIC23 simultaneously which contains 32 complex floating point entities. But i am still unable to do so because AIC23 can send only one integer (32-bits) in one time slot.

Can you please guide me how can I do this? Can I use AIC23 for this task or I have to use RTDX or different daughter cards for this purpose.

Waiting for the response.

Thank you.

Thank you for your nice response omap33.

I have completed OFDM Modulation and demodulation on DSP C6713. Now I am trying to transmit an OFDM symbol and then receive that signal and perfom OFDM demodulation on another DSP C6713.

And after that I have to integrate OFDM with MIMO Technology. I have to transmit multiple OFDM symbols from one DSP and then receive these symbols and on another DSP perform V-Blast algorithm to extract OFDM symbols and then demodulate each OFDM symbol.

At this part, I am facing problems in DSP performance and peripherals.

Any help regarding to that.

Thank you so much. 

omap33,

I am not familiar with any publicly available libraries, although I am sure we have developed software under contract or under NDA or license for specific uses. If you have additional detail you can supply on publicly available libraries for use by Hassaan Siddiqui, please do.

Hassaan Siddiqui,

I found an application note that may be of some interest to you. It is >10 years old and does not have all the specific details, but it may help guide you. This app note is called Real-Time Implementation of a COFDM Modem for Data Transmission over HF Channels with the TMS320C31 DSP.

TI has a wide variety of RF and IF devices for communication. Please search www.ti.com for information on OFDM and see what devices may be helpful for you.

Thank you RandyP for your nice response.

I have studied the article you shared. But this is not related to work which i am trying to do.

I have implemented OFDM Baseband System and now trying to integrate it with MIMO Baseband System. After that I have to made full communication system by integrating this baseband system with passband hardware system i.e. 2 RF transmitters and 2 RF receivers.

For this purpose I have only C6713 DSK with only audio ports. No daughter cards or data acquisition card are available in my lab. That is why I am facing problems? 

I am trying but audio ports are not supporting. Any Suggestions?

Thanks a lot.

I am not an expert in communications theory. You need to be an expert in communications theory to implement an OFDM communications system from the lowest level as you are trying to do.

TI sells very useful components for communications. One of the latest is the WL1271 which can be connected to some of our newer EVMs to implement wireless communication standards.

The document I referenced above, which you studied, includes block diagrams of communication system implementations. It shows the basic blocks inside the box. Can you indicate in one of these block diagrams where the signalling exists that you want to forward through the AIC23? You mentioned having 32 complex floating point entities for your symbols - do these represent points in the frequency domain or time domain?

The TLV320AIC23 on the C6713 implements dual Line Outputs and dual Line Inputs, so you have the right number of analog outputs to send baseband signals to the MIMO RF.

To what RF frequency do you plan to modulate your baseband signals?

Do you need to match any existing communication standard, or is this purely your self-designed system?

What symbol-rate do you want to achieve?

How much time per symbol will you allow?

Thanks RandyP.

Referring to Figure 1 of the document you mentioned. In the Transmitter Design, D/A (after IFFT) is the block which I want AIC23 to be used as. The output of IFFT is 16 complex floating point numbers in time domain that makes an OFDM symbol. And I have to transmit 2 OFDM symbols simultaneously. In Receiver Design of Figure 1, A/D is the block which I want AIC23 to be used as.

Referring to Figure 7 Modem Transmitter Section, In my case, The signal from the DSP is 2 x 16 floating point numbers in time domain and they will be fed into AIC23 and after being converted into analog signal they will be modulated on 400MHz carrier signal. In my case, SSB Transmitter is a 400MHz FSK/FM Modulator.

Referring to Figure 8 Modem Receiver Section, In my case, SSB Receiver is 400MHz FSK/FM Demodulator whose output will be fed to A/D (AIC23) which will convert the analog signal into digital 2 x 16 floating point numbers in time domain. 

All the baseband processing of MIMO-OFDM Transmitter and Receiver will be done in DSP C6713.

RF Frequency is almost 400MHz.

I do not need to match any existing communication standard, this is my Bachelor's Degree Final Year Project.

What maximum time per symbol can C6713 handle? 

Hi Hassaan Siddiqui,

I am newbie with DSP. I plan to implement an OFDM Baseband system (TX and RX). As I know, all things is realized by programming for DSP. That is true ?

You say that you use C6713 DSK, don't you ? It is grateful if you kindly send me the code for OFDM (?)

Thank you so much in advance,

Thang