wiki:OFDMReferenceDesign

Version 40 (modified by murphpo, 16 years ago) (diff)

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WARP OFDM Reference Design

Please read our ESD warning before using your WARP hardware with this reference design

The WARP OFDM Reference Design implements a wired-wireless bridge, creating a link between two PCs using a wireless connection between two WARP nodes in place of an Ethernet cable. This link allows the PCs to communicate as if they were connected directly via Ethernet.

No image "overview_01a.jpg" attached to OFDMReferenceDesign/Files

Requirements:

  • Two SISO or MIMO WARP nodes
  • Two PCs with Ethernet interfaces
  • OFDM Reference Design programming file or XPS project

WARP Hardware Setup

You will need two WARP nodes to test this reference design. Each node should have an antenna connected to the radio in daughtercard slot #2. Each node's Ethernet port should be connected to a PC, either directly or via a switch. The two WARP nodes should not be connected to the same Ethernet switch.

The two nodes will be programmed by the same bit file, but they must be uniquely identified to allow the wireless MAC layer to properly address each node. The FPGA board's DIP switch is used to identify each node. One board should have its DIP switch set to all zeros (0000); the other should be set to 0001. See the figure below for the proper settings.

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When you download the reference design to a WARP node, the FPGA board's seven-segment dipslay will show the node's ID, either 0 or 1.

Computer Setup

The WARP wired-wireless bridge allows the PC connected to a WARP node to communicate with the other PC as if they were connected directly via Ethernet. In order to communicate something useful, the two PCs must have their IP addresses configured manually. We suggest the following IP settings:

  • PC 1 IP Address: 10.0.0.1
  • PC 2 IP Address: 10.0.0.2
  • Subnet mask (both PCs): 255.255.255.0

Technically, any pair of IP addresses in the same subnet will work.

Running the Reference Design

Configure both WARP nodes using the refence design bitstream. New WARP kits include the bitstream in position 1 of the bunlded CompactFlash card (position 0 is a simplier demo which does not require a PC). You can also download the bitstream directly via iMPACT using the FPGA board's built-in USB JTAG programming circuit.

Once both WARP nodes are configured, you should be able to ping each PC from the other. You can then run any IP-based networking application between the PCs. We suggest using VLC to stream video from one PC to the other. We have written a brief tutorial on setting up VLC. You can see this exact demo running in our demo videos.

Reference Design Files

The full OFDM Reference Design is available for download. The ZIP files below contain the full XPS 9.1 project for the OFDM reference design, including both the hardware and software designs.

Two version are available:

  • OFDM Reference Design v04 (60MB .zip file) - For kits without a 40MHz converter reference clock.
  • OFDM Reference Design v07 (63MB .zip file) - For kits with a 40MHz converter reference clock. If your kits have twisted white/green cables connecting your clock board to each radio board, use this design.

This design integrates the various hardware, PHY and MAC cores and code we have built. The individual cores and source files are also available in the WARP repository.

If you want to test the design as-is, use the file '/implementation/download.bit' from the ZIP file.

If you want to make changes and update the bitstream, you will probably need to update the linker script. In XPS, choose Software->Generate Linker Script. Make sure your script settings match those shown below. It is critical that no code sections be assigned to the memory block plb_bram_if_cntlr_2.

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Old Reference Designs

OFDM Reference Design v03

OFDM Reference Design v02