| | 94 | |
| | 95 | What we observe from the above plot is not a perfect sine wave,.This is because that we set the target frequency as 1MHz, which is out of the working range of BasicRX and BasicTX. Recall that the working range of BasicRX and BasicTX is from 2MHz to 200MHz+. Now let’s try to set the correct frequency. |
| | 96 | |
| | 97 | 3. '''Transmitter and Receiver at 10MHz''' The transmitter sends out waveform at 10MHz, and the receiver receives at 10MHz as well. |
| | 98 | At the Transmitter node1-1: |
| | 99 | {{{ |
| | 100 | ./usrp_siggen_multiple_sine.py -f 10e6 -w 10k -a 1000 -m 1 --sine |
| | 101 | }}} |
| | 102 | * '-f 10e6': tells the GnuRadio to modulate the baseband waveform to 10MHz. |
| | 103 | * '--sine': the format of the waveform that will be sent out is a sine wave. |
| | 104 | * '-w 10k': set the original baseband frequency to 10k, |
| | 105 | * '-a 1000': set the amplitude to 1000. |
| | 106 | * '-m 1': only transmit one sine wave, instead of multiple sine waves. |
| | 107 | |
| | 108 | At the receiver node1-2: |
| | 109 | {{{ |
| | 110 | ./usrp1_rx_cfile.py -f 10e6 -N21000 -g 10 rx_1m.dat |
| | 111 | }}} |
| | 112 | * '-f 10e6': tells the GnuRadio to listen to the frequency band 1MHz. |
| | 113 | * '-N21000': sample 21000 data points. |
| | 114 | * '-g 10': set the gain to 10. |
| | 115 | * 'rx_10m.data': set the file name that will store the data samples. |
| | 116 | |
| | 117 | |
| | 118 | Using the matlab script [http://www.orbit-lab.org/attachment/wiki/Documentation/GNURadio/plotall.m plotall('rx_10m.dat')], you can get the following figure: |
| | 119 | |
| | 120 | [[Image(Documentation/GNURadio:rx_10m.dat.jpeg)]] |
| | 121 | |
| | 122 | This time the received sine wave is indeed a regular sine wave. |
| | 123 | |
