Changes between Version 12 and Version 13 of WARPLab/Examples/8x2Array
- Timestamp:
- May 14, 2013, 9:36:52 AM (11 years ago)
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WARPLab/Examples/8x2Array
v12 v13 1 1 [[TracNav(WARPLab/TOC)]] 2 2 = WARPLab 7 Example: 8x2 Array = 3 File: [source: ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_8x2_array.m wl_example_8x2_array.m]3 File: [source:/ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_8x2_array.m wl_example_8x2_array.m] 4 4 5 5 This example shows how WARPLab can be used for array communications even when the number of antennas exceeds what can be supported on a single WARP board. This example uses two separate WARP boards to act as a single many-antenna transmitter while a third board receives their transmissions. … … 33 33 1. Power on the third WARP v3 board and download the 2RF WARPLab reference bitstream. The node should boot and show "03" on the hex displays. 34 34 35 Please refer to the [wiki:../../HardwareConfiguration WARPLab Hardware Configuration] user guide for more details on each of these steps. 35 36 36 37 [[Image(8x2_cable_macro.jpg,width=800)]] 37 38 [[Image(8x2_cable_micro.jpg,width=800)]] 38 39 40 Once the hardware is connected and programmed you can run the example m code: [source:/ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_8x2_array.m wl_example_8x2_array.m]. 39 41 40 == Running the Script == 42 == Example Overview == 43 44 In this example, we use each of the 8 transmit antennas to generate "pink" noise that is bandlimited to 1 MHz and digitally mixed to one of 8 different frequencies [-12, -8.5714 , -5.1429, -1.7143, 1.7143, 5.1429, 8.5714, 12] MHz. Note: these are frequencies relative to baseband, so 0 MHz corresponds to the center frequency of the radio (Channel 11 of the 2.4 GHz band by default). These 8 different signals are all transmitted simultaneously and are then captured through two receive antennas on the receiving board. Visualizations of those receptions are then plotted. 45 46 The purpose of this example is to show how multiple transmit nodes should be synchronized. This technique can scale to arrays even larger than 8 transmit antennas. A similar technique was used in the [wiki:/Projects/Rice_Argos Rice University Argos Project]. 47 48 == Observations == 49 50 When you run the example script, it will produce a plot that looks like this 41 51 42 52 [[Image(8x2_result.png,width=800)]] 53 54 The top-left subplot shows the real part of the received waveform through interface RFA on the board. The top-right subplot shows the real part of the received waveform through interface RFB. The two plots below those show the magnitudes of the signals after FFTs are taken, allowing us to see the 8 different 1 MHz-wide noise signals that were transmitted. Note that the heights (magnitudes) of each of these 8 signals are different due to frequency selective fading. If you change [source:/ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_8x2_array.m#L15 line 15 of wl_example_8x2_array.m] to "true," then the script will loop and repeatedly transmit, receive, and produce plots until any key is pressed on the keyboard of the host PC that is running MATLAB. While it is running, you can move antennas around and walk through the room for an interesting animated visualization of frequency selective fading.
