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802.11 Application with USRP-2901

Hello, 

Recently I saw the white paper mentioning "LabVIEW Communications 802.11 Application Framework 2.0 White Paper".

http://www.ni.com/white-paper/53279/en/#_Toc451257165

Sounds very interesting to me ! 

I see that it uses USRP RIO. Also it implements all the RF and baseband processing inside the FPGA. I have two questions : 

1. Can I do the same with USRP-2901 knowing the fact that USRP-2901 communicates thru USB 3.0 (which is slower than RIO PCI connector) and USRP-2901 has smaller FPGA, compared to RIO. 

2. Will it be possible to achive the same Timing budget for transmission after frame reception if my entire baseband processing happens in the CPU instead of FPGA ? 

TIA

Sumit 

 

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Hi sumitstop1,

 

I'm glad you found the white paper interesting! To answer your questions:

 

1. It is not possible to use the USRP-2901. There are a couple of reasons for this. The USRP-2901 is not a LabVIEW FPGA target, so it's not even possible to program the FPGA with LabVIEW Communications. Even if it were, the FPGA on the 2901 is much, much smaller than a USRP RIO. The 802.11 application framework, as you mentioned, uses this heavily, so the smaller FPGA wouldn't work. And, as you also mentioned, the USB 3.0 connection is both slower and less deterministic than a PCIe connection, which poses a big problem too.

 

2. Probably not. 802.11 requires a remarkably fast turnaround time. SIFS timing can be as short as 10 uS, which is not easy for a CPU to meet, and certainly not meet reliably. This is why we utilize the FPGA so extensively. 

 

Fortunately, this works great on a USRP RIO!

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Hello, 

Thanks for your reply. 

Do you have any framework in labview thru which I can measure the latency. I wish to measure the latency from FPGA to host CPU while receiving. 

Regards

Sumit 

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