Changes between Version 35 and Version 36 of OFDMReferenceDesign


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Timestamp:
Nov 20, 2007, 2:25:21 PM (16 years ago)
Author:
murphpo
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  • OFDMReferenceDesign

    v35 v36  
    11{{{
    2 #!NewsFlash
    3 = v04 Update - June 25, 2007 =
    42
    5 +updated to flexible-modulation capable PHY
    6 
    7 }}}
    8 
    9 
    10 = OFDM Networking Reference Design =
     3= WARP OFDM Reference Design =
    114
    125'''Please read our [wiki:ESD ESD warning] before using your WARP hardware with this reference design'''
    136
    14 By default, this project creates a custom wireless Ethernet link between two computers, each attached to a WARP node (FPGA board + clock board + radio board).  Each computer is unaware that a wireless link is present, and simply communicates with its neighbor using a standard wired connection.  The WARP boards are "inserted" between the two computers to provide a transparent wireless bridge.  The following diagram gives a simple overview of the configuration used in this example.
     7The 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.
    158
    169[[Image(OFDMReferenceDesign/Files:overview_01a.jpg)]]
    1710
    18 If it is impractical to obtain two dedicated computers for this example, the WARP link may be inserted into the wired connection between a single computer and a DHCP server.  In this "alternate" configuration, the WARP boards are typically inserted between the computer and an RJ45 jack in a laboratory or office.  Although this alternate configuration may appear to be a simpler one, it may actually be more difficult to troubleshoot if any problems arise.
     11'''Requirements''':
     12 * Two SISO or MIMO WARP nodes
     13 * Two PCs with Ethernet interfaces
     14 * OFDM Reference Design programming file or XPS project
    1915
    20 Regardless of the chosen configuration (one computer or two computers), the WARP nodes implemening the wireless link treat Ethernet packets ONLY as payload.  Packets are received and forwarded without any IP processing.
     16== WARP Hardware Setup ==
    2117
    22 == Initial Hardware Setup ==
     18You 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.
    2319
    24 The following image illustrates a complete set of hardware used to implement this example.  IF YOU HAVE NOT ALREADY DONE SO, NOW WOULD BE A GOOD TIME TO WORK THROUGH THE LABORATORY EXERCISE titled [http://warp.rice.edu/trac/wiki/Exercises/FPGABoardIntro INTRODUCTION TO THE WARP FPGA BOARD].  This introductory exercise provides a solid introduction to using the boards, including detailed illustrations of correct cable connections.
    25 
    26 [[Image(OFDMReferenceDesign/Files:setup_01a.jpg)]]
    27 
    28 Before proceeding, verify that the Master Power switch on each WARP FPGA board has been switched to the OFF position. 
    29 
    30 [[Image(OFDMReferenceDesign/Files:setup_01b.jpg)]]
    31 
    32 Several cable connections must be made on each WARP kit before this demo may be performed:
    33 
    34    - a 12 V power supply connection to the FPGA board's power input;
    35    - an antenna connection to the "outside" antenna port of the radio board;
    36    - an MMCX-to-MMCX cable connected between the clock board and the radio board; and
    37    - a wired Ethernet connection between each WARP kit and one of the local computers.
    38 
    39 The following images illustrate several of these connections.  EXERCISE EXTREME CAUTION WHEN PLUGING A CABLE INTO THE CLOCK BOARD, AS THE INTERFACE BETWEEN IT AND THE FPGA BOARD IS EXTREMELY DELICATE!  THE CLOCK BOARD SHOULD BE GRASPED FIRMLY BE THE EDGES TO PREVENT ANY ROCKING MOTION WHEN INSTALLING THE MMCX-TO-MMCX CABLE.
    40 
    41 [[Image(OFDMReferenceDesign/Files:setup_02a.jpg)]]
    42 
    43 [[Image(OFDMReferenceDesign/Files:setup_03a.jpg)]]
    44 
    45 [[Image(OFDMReferenceDesign/Files:setup_04a.jpg)]]
    46 
    47 Please note that you may have additional connections to the WARP boards, beyond those identified above.  If, for example, you have recently worked through the exercise titled [http://warp.rice.edu/trac/wiki/Exercises/FPGABoardIntro INTRODUCTION TO THE WARP FPGA BOARD], then you may have a serial cable and a USB cable connected between your WARP boards and their corresponding computers.
    48 
    49 The user DIP switches on one WARP node should be set to the binary value 0000.  The user DIP switches on the other WARP node should be set to the value 0001.
     20The 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.
    5021
    5122[[Image(OFDMReferenceDesign/Files:setup_05a.jpg)]]
    5223
    53 When power is applied to the WARP nodes, the value on the each board's 7-segment display (the display closer to the user DIP switches) should reflect these settings -- either "0" or "1".
     24When 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.
    5425
    55 The compact flash configuration DIP switches permit the selection of different FPGA programs from a selection of programs stored on a compact flash card.  If you are configuring the FPGA boards using a compact flash card (instead of from a USB connection), then the configuration switches must be set to the correct value for the desired program.  In general, demo applications will be delivered on a compact flash card at location 0, so set the configuration DIP switches to the value 0000.  DEPENDING UPON YOUR BOARD REVISION, THE SILKSCREEN NEAR THE CONFIGURATION DIP SWITCHES MAY INCORRECTLY SPECIFY THE DIRECTION FOR THE SWITCH VALUES 0 AND 1!  The value 0000 is achieved when all switches are pushed away from the nearest board edge.
     26== Computer Setup ==
    5627
    57 [[Image(OFDMReferenceDesign/Files:setup_06a.jpg)]]
     28The 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:
    5829
    59 == Initial Computer Setup (Two Computers) ==
     30 * PC 1 IP Address: 10.0.0.1
     31 * PC 2 IP Address: 10.0.0.2
     32 * Subnet mask (both PCs): 255.255.255.0
    6033
    61 Since two local computers will be connected to each other, there will not be a DHCP server available to supply IP addresses to either of them.  In this scenario, the computers must have their IP addresses hard-coded.  Furthermore, the two computers must reside within the same subnet.  The following addresses and subnet masks are just one example of acceptable settings for this demo:
     34Technically, any pair of IP addresses in the same subnet will work.
    6235
    63    - COMPUTER 1 IP ADDRESS = 192.168.1.16,
    64    - COMPUTER 2 IP ADDRESS = 192.168.1.17,
     36== Running the Reference Design ==
    6537
    66    - COMPUTER 1 SUBNET MASK = 255.255.255.0,
    67    - COMPUTER 2 SUBNET MASK = 255.255.255.0.
     38Configure 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.
    6839
    69 == Initial Computer Setup (One Computer) ==
    70 
    71 In the one-computer configuration, a single computer is connected to a DHCP server through the WARP wireless link.  The computer should be configured to obtain its IP address automatically.
    72 
    73 == Running the Demo ==
    74 
    75 Switch the Master Power Switch for each FPGA board to the ON state.
    76 Configure the FPGA boards using either 1) a compact flash card containing the demo program, or 2) a USB cable connected between the FPGA board and a computer running the Xilinx iMPACT software application.  The laboratory exercise titled [http://warp.rice.edu/trac/wiki/Exercises/FPGABoardIntro INTRODUCTION TO THE WARP FPGA BOARD] provides a brief introduction to the iMPACT software application, including required cable connections.  For configuration using a compact flash card, simply insert the card into the appropriate slot on one of the FPGA boards.  An photo of the compact flash card slot appears below.
    77 
    78 [[Image(OFDMReferenceDesign/Files:setup_07a.jpg)]]
    79 
    80 Once the first FPGA board has been configured, the compact flash card may be removed for use in configuring of the other board.  Before removing it, however, verify proper configuration by examining the board's 7-segment LEDs.  The one closer to the user DIP switches should display the value programmed into the switches -- either "0" or "1.
    81 
    82 
    83 
    84 == Example System Configuration 1 ==
    85 
    86 The user will need to supply two computers and two WARP nodes (1 node = 1 FPGA[v1.2] + 1 Radio[v1.4]). The computers need to be configured to have hardcoded IP addresses within each other's addressable range. In other words, they must be in each other's subnet to be able to talk to one another. For example, one computer can be 10.0.0.8 and the other can be 10.0.0.9 and each can have a subnet mask of 255.255.255.0.
    87 
    88 One FPGA board '''must''' by configured as Node 0, and other as Node 1, using the on-board dip switches. The switch closest to the power supplies represents the node value. When the program is downloaded, the seven-segment LEDs should show the node values.
    89 
    90 Using ethernet, connect one PC to one board, and the other PC to the other board. Note, if the PCs are using older network cards that do not support auto MDI/MDI-X, the user may need to provide crossover ethernet cables instead of standard cables. Once the boards are connected and configures, any traffic directed to one computer's IP address from the other computer will be forwarded.
    91 
    92 == Example System Configuration 2 ==
    93 
    94 The user will need to supply one computer and two WARP nodes. Enable DHCP on the computer (most likely already enabled, unless the user tried the first configuration).
    95 
    96 One FPGA board '''must''' by configured as Node 0, and other as Node 1, using the on-board dip switches. The switch closest to the power supplies represents the node value. When the program is downloaded, the seven-segment LEDs should show the node values.
    97 
    98 Connect the PC to a board using a standard or crossover ethernet cable. Connect the other board to an internet source (e.g. the wall, a router, etc). The computer will then be able to access network resources via the WARP OFDM link.
     40Once 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 [wiki:VLCStreaming brief tutorial] on setting up VLC. You can see this exact demo running in our [http://youtube.com/profile_videos?user=ricewarp demo videos].
    9941
    10042== Reference Design Files ==
    10143
    102 Download the full reference design here: [http://warp.rice.edu/bigFiles/OFDM_ReferenceDesign_v04.zip OFDM Reference Design v04] (60MB .zip file).  This ZIP file contains the full XPS project for the OFDM reference design, including both the hardware and software designs.
     44The full OFDM Reference Design is available for download here: [http://warp.rice.edu/bigFiles/OFDM_ReferenceDesign_v04.zip OFDM Reference Design v04] (60MB .zip file). This ZIP file contains the full XPS 9.1 project for the OFDM reference design, including both the hardware and software designs.
     45
     46This 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 [source:/ WARP repository].
    10347
    10448If you want to test the design as-is, use the file '/implementation/download.bit' from the ZIP file.
    10549
    106 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.
     50If 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''.'''
    10751
    10852[[Image(OFDM_RefDesign_LinkerScript.jpg)]]