1 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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2 | % Spectrum sensing using WARPLab |
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3 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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4 | |
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5 | % The specific steps implemented in this script are the following: |
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6 | |
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7 | % 0. Initialization and definition of parameters |
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8 | % 1. Prepare the WARP node for reception (sensing the medium) and send trigger to |
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9 | % start reception (trigger is the SYNC packet) |
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10 | % 2. Read the received samples from the WARP node |
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11 | % 3. Reset and disable the WARP node |
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12 | % 4. Compute and plot the fft of the received data |
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13 | % 5. Plot the received waveform |
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14 | % 6. Compute the Received Signal Strength Indicator (RSSI in dBm) of the received signal |
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15 | % 7. Close sockets |
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16 | |
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17 | % In this lab exercise you will write a matlab script that implements the |
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18 | % steps above. Part of the code is provided, some part of the code you |
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19 | % will write. Read the code below and fill in with your code wherever you |
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20 | % are asked to do so. |
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21 | |
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22 | % WARPLab documentation can be found online at |
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23 | % http://warp.rice.edu/trac/wiki/WARPLab |
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24 | |
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25 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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26 | |
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27 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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28 | % 0. Initializaton and definition of parameters |
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29 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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30 | |
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31 | %Load some global definitions (packet types, etc.) |
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32 | warplab_defines |
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33 | |
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34 | % Create Socket handles and intialize nodes |
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35 | [socketHandles, packetNum] = warplab_initialize(1); |
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36 | |
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37 | % Separate the socket handles for easier access |
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38 | % The first socket handle is always the magic SYNC |
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39 | % The rest of the handles are the handles to the WARP nodes |
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40 | udp_Sync = socketHandles(1); % SYNC |
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41 | udp_node1 = socketHandles(2); % Handle for node 1: Receiver node |
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42 | |
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43 | % Define WARPLab parameters for this workshop exercise. |
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44 | |
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45 | %-------------------------------------------------------------------------% |
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46 | % USER CODE HERE |
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47 | |
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48 | % - Create a variable named 'Node1_SensingChannel' and assign a value to |
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49 | % this variable . |
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50 | % - Variable 'Node1_SensingChannel' can be any integer value in [1:14] range. |
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51 | % - The value of Node1_SensingChannel specifies a channel in the 2.4 GHz band |
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52 | % and this is the channel at which sensing wll be centered |
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53 | |
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54 | Node1_SensingChannel = 1; |
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55 | %-------------------------------------------------------------------------% |
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56 | |
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57 | %-------------------------------------------------------------------------% |
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58 | % USER CODE HERE |
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59 | |
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60 | % - Set the sensing channel of node 1 by using the 'warplab_setRadioParameter' |
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61 | % function and the 'Node1_SensingChannel' variable just defined |
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62 | |
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63 | % The 'warplab_setRadioParameter' function has three arguments which are specified below: |
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64 | %(The arguments in the 'warplab_setRadioParameter' function do not use the quotes '') |
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65 | |
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66 | % 1. The first argument of the 'warplab_setRadioParameter' function identifies the |
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67 | % node where the radio parameter will be set. The id or handle to node 1 is |
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68 | % 'udp_node1'. |
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69 | |
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70 | % 2. The second argument of the 'warplab_setRadioParameter' function identifies the |
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71 | % radio parameter that will be set. The sensing channel is the receiver center |
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72 | % frequency or carrier channel. To set the sensing channel, the radio |
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73 | % parameter that needs to be set is the parameter identified as |
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74 | % 'CARRIER_CHANNEL'. |
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75 | |
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76 | % 3. The third argument of the 'warplab_setRadioParameter' function is the channel |
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77 | % number to be set. Use as third argument the variable 'Node1_SensingChannel' |
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78 | % that you have previously defined |
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79 | |
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80 | warplab_setRadioParameter(udp_node1,CARRIER_CHANNEL,Node1_SensingChannel); |
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81 | %-------------------------------------------------------------------------% |
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82 | |
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83 | %-------------------------------------------------------------------------% |
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84 | % USER CODE HERE |
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85 | |
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86 | % - Create a variable named 'Node1_Radio2_RxGain_BB' and assign a value to |
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87 | % this variable . |
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88 | % - Node1_Radio2_RxGain_BB can be any integer value in [0:31] range. |
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89 | % - Node1_Radio2_RxGain_BB is the baseband gain applied by the receiver. |
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90 | % - Each unit step increase in the value of Node1_Radio2_RxGain_BB |
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91 | % corresponds to a 2 dB increase of gain applied to the received signal. |
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92 | |
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93 | Node1_Radio2_RxGain_BB = 13; |
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94 | %-------------------------------------------------------------------------% |
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95 | |
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96 | |
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97 | %-------------------------------------------------------------------------% |
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98 | % USER CODE HERE |
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99 | |
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100 | % - Create a variable named 'Node1_Radio2_RxGain_RF' and assign a value to |
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101 | % this variable . |
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102 | % - Node1_Radio2_RxGain_RF can be any integer value in [1:3] range. |
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103 | % - Node1_Radio2_RxGain_RF is the RF gain applied by the receiver. |
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104 | % - Each unit step increase in the value of Node1_Radio2_RxGain_RF |
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105 | % corresponds to a 15 dB increase of gain applied to the received signal. |
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106 | |
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107 | Node1_Radio2_RxGain_RF = 3; |
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108 | %-------------------------------------------------------------------------% |
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109 | |
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110 | % Set the baseband and RF receiver gains of the radio by using the 'warplab_setRadioParameter' |
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111 | % function and the 'Node1_Radio2_RxGain_BB' and 'Node1_Radio2_RxGain_RF' variables just defined |
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112 | warplab_setRadioParameter(udp_node1,RADIO2_RXGAINS,(Node1_Radio2_RxGain_BB + Node1_Radio2_RxGain_RF*2^16)); |
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113 | |
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114 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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115 | % 1. Prepare the WARP node for reception (sensing the medium) and send trigger to |
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116 | % start reception (trigger is the SYNC packet) |
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117 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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118 | |
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119 | %-------------------------------------------------------------------------% |
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120 | % USER CODE HERE |
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121 | |
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122 | % Enable radio 2 in node 1 as receiver by sending the 'RADIO2_RXEN' command |
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123 | % to node 1 using the 'warplab_sendCmd' function. |
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124 | |
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125 | % The 'warplab_sendCmd' function has three arguments which are specified below: |
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126 | %(The arguments in the 'warplab_setRadioParameter' function do not use the quotes '') |
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127 | |
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128 | % 1. The first argument of the 'warplab_sendCmd' function identifies the |
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129 | % node to which the command will be sent to. The id or handle to node 1 is |
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130 | % 'udp_node1'. |
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131 | |
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132 | % 2. The second argument of the 'warplab_sendCmd' function identifies the |
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133 | % command that will be sent. |
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134 | |
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135 | % 3. The third argument of the 'warplab_sendCmd' command is a field that is |
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136 | % not used at the moment, it may be used in future versions of WARPLab to |
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137 | % keep track of packets. Use 'packetNum' as the third argument of the |
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138 | % 'warplab_sendCmd' function. |
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139 | |
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140 | warplab_sendCmd(udp_node1, RADIO2_RXEN, packetNum); |
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141 | %-------------------------------------------------------------------------% |
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142 | |
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143 | %-------------------------------------------------------------------------% |
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144 | % USER CODE HERE |
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145 | |
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146 | % Enable storage of samples in the receive buffer that is connected to |
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147 | % radio 2 in node 1 by sending the RADIO2RXBUFF_RXEN command to |
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148 | % node 1 using the 'warplab_sendCmd' function. |
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149 | |
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150 | % The 'warplab_sendCmd' function has been described above |
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151 | |
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152 | warplab_sendCmd(udp_node1, RADIO2RXBUFF_RXEN, packetNum); |
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153 | %-------------------------------------------------------------------------% |
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154 | |
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155 | % Prime receiver state machine in node 1. Node 1 will be waiting |
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156 | % for the SYNC packet. Capture at node 1 will be triggered when node 1 |
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157 | % receives the SYNC packet. |
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158 | warplab_sendCmd(udp_node1, RX_START, packetNum); |
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159 | |
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160 | % Send the SYNC packet |
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161 | warplab_sendSync(udp_Sync); |
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162 | |
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163 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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164 | % 2. Read the received samples from the WARP node |
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165 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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166 | BufferSize = 2^14; |
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167 | |
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168 | %-------------------------------------------------------------------------% |
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169 | % USER CODE HERE |
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170 | |
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171 | % Read the received samples from the WARP node using the |
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172 | % 'warplab_readSMRO' function. Store the samples output by the warplab_readSMRO |
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173 | % function samples in a variable named 'Node1_Radio2_RawRxData'. |
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174 | |
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175 | % The arguments of the 'warplab_readSMRO' function are the following: |
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176 | %(The arguments in the 'warplab_setRadioParameter' function do not use the quotes '') |
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177 | |
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178 | % 1. The first argument of the 'warplab_readSMRO' function identifies the |
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179 | % node from which samples will be read. In this exercise there is only one |
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180 | % node and the id or handle to node 1 is 'udp_node1'. |
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181 | |
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182 | % 2. The second argument of the 'warplab_readSMRO' function identifies the |
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183 | % receive buffer from which samples will be read. For this exercise samples |
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184 | % were captured in node 1 radio 2, hence, samples must be read from radio 2 |
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185 | % Rx buffer, the id for this buffer is 'RADIO2_RXDATA'. |
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186 | |
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187 | % 3. The third argument of the 'warplab_readSMRO' function is the number of |
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188 | % samples to read; reading of samples always starts from address zero in |
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189 | % the receive buffer. For this exercise set the third argument of the 'warplab_readSMRO' |
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190 | % function equal to 'BufferSize' which has been defined in the code to be |
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191 | % equal to 2^14 which is the maximum number of samples that can be stored |
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192 | % in the receive buffer, hence you will read the entire receive buffer |
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193 | |
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194 | [Node1_Radio2_RawRxData] = warplab_readSMRO(udp_node1, RADIO2_RXDATA, BufferSize); |
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195 | %-------------------------------------------------------------------------% |
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196 | |
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197 | % Process the received samples to obtain meaningful data |
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198 | [Node1_Radio2_RxData,Node1_Radio2_RxOTR] = warplab_processRawRxData(Node1_Radio2_RawRxData); |
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199 | |
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200 | % Read stored RSSI data |
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201 | [Node1_Radio2_RawRSSIData] = warplab_readSMRO(udp_node1, RADIO2_RSSIDATA, ceil(BufferSize/8)); |
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202 | |
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203 | % Process Raw RSSI data to obtain meningful RSSI values |
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204 | [Node1_Radio2_RSSIData] = warplab_processRawRSSIData(Node1_Radio2_RawRSSIData); |
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205 | |
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206 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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207 | % 3. Reset and disable the WARP node |
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208 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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209 | %-------------------------------------------------------------------------% |
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210 | % USER CODE HERE |
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211 | |
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212 | % Set radio 2 in node 1 back to Rx disabled mode by sending the |
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213 | % 'RADIO2_RXDIS' command to node 1 using the 'warplab_sendCmd' function. |
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214 | |
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215 | % The 'warplab_sendCmd' function has been described above |
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216 | |
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217 | warplab_sendCmd(udp_node1, RADIO2_RXDIS, packetNum); |
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218 | %-------------------------------------------------------------------------% |
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219 | |
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220 | %-------------------------------------------------------------------------% |
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221 | % USER CODE HERE |
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222 | |
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223 | % Set storage of samples in the receive buffer that is connected to |
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224 | % radio 2 in node 1 back to disabled mode by sending the RADIO2RXBUFF_RXDIS |
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225 | % command to node 1 using the 'warplab_sendCmd' function. |
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226 | |
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227 | warplab_sendCmd(udp_node1, RADIO2RXBUFF_RXDIS, packetNum); |
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228 | %-------------------------------------------------------------------------% |
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229 | |
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230 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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231 | % 4. Compute and plot the fft of the received data |
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232 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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233 | % Computation of fft is based on the example in MATLAB's fft |
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234 | % documentation, see help fft for more information on MATLAB's fft function |
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235 | |
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236 | % Compute and plot the fft of the received signal |
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237 | % Compute fft |
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238 | L=length(Node1_Radio2_RxData); % Get length of transmitted vector |
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239 | NFFT = 2^nextpow2(L); % Next power of 2 from length of y |
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240 | Y = fftshift(fft(Node1_Radio2_RxData,NFFT)/L); % Compute fft |
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241 | Fs=40e6; % Sampling frequency is equal to 40e6 |
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242 | f = Fs/2*linspace(0-1,1,NFFT); |
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243 | |
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244 | % Plot fft |
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245 | figure |
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246 | plot(f/10^6,abs(Y)) |
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247 | title('Spectrum of received signal in current carrier channel') |
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248 | xlabel('Frequency (MHz)') |
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249 | ylabel('Magnitude') |
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250 | xlim([-10 10]) |
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251 | |
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252 | |
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253 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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254 | % Attendees code: |
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255 | % 5. Plot the received waveform |
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256 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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257 | figure |
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258 | subplot(2,2,1); |
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259 | plot(real(Node1_Radio2_RxData)); |
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260 | title('Rx Node 2 Radio 2 I'); |
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261 | xlabel('n (samples)'); ylabel('Amplitude'); |
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262 | axis([0 2^14 -1 1]); % Set axis ranges. |
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263 | subplot(2,2,2); |
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264 | plot(imag(Node1_Radio2_RxData)); |
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265 | title('Rx Node 2 Radio 2 Q'); |
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266 | xlabel('n (samples)'); ylabel('Amplitude'); |
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267 | axis([0 2^14 -1 1]); % Set axis ranges. |
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268 | |
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269 | % Plot amplitude versus time |
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270 | subplot(2,2,3); |
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271 | plot([0:1:length(Node1_Radio2_RxData)-1]/40e6,real(Node1_Radio2_RxData)); |
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272 | title('Rx Node 2 Radio 2 I'); |
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273 | xlabel('time (s)'); ylabel('Amplitude'); |
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274 | axis([0 (length(Node1_Radio2_RxData)-1)/40e6 -1 1]); % Set axis ranges. |
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275 | subplot(2,2,4); |
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276 | plot([0:1:length(Node1_Radio2_RxData)-1]/40e6,imag(Node1_Radio2_RxData)); |
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277 | title('Rx Node 2 Radio 2 Q'); |
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278 | xlabel('time (s)'); ylabel('Amplitude'); |
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279 | axis([0 (length(Node1_Radio2_RxData)-1)/40e6 -1 1]); % Set axis ranges. |
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280 | |
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281 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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282 | % 6. Compute the Received Signal Strength Indicator (RSSI in dBm) of the received signal |
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283 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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284 | % RSSI measurements were stored in 'Node1_Radio2_RSSIData' variable. |
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285 | % Average over all measurements of RSSI |
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286 | RSSI_Avg = mean(Node1_Radio2_RSSIData); |
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287 | |
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288 | % Convert RSSIAvg to dBm. |
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289 | % The conversion is based on the following radio and RSSI vaue specifications: |
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290 | % For high receiver gain (Node1_Radio2_RxGain_RF = 3), RSSI_Avg=0 is -100dBm; RSSI_Avg=1023 is -30dBm. |
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291 | % For medium receiver gain (Node1_Radio2_RxGain_RF = 2), RSSI_Avg=0 is -85dBm; RSSI_Avg=1023 is -15dBm. |
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292 | % For low receiver gain (Node1_Radio2_RxGain_RF = 1), RSSI_Avg=0 is -70dBm; RSSI_Avg=1023 is 0dBm. |
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293 | |
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294 | RSSI_dBm = (70/1023)*RSSI_Avg - 70 - (Node1_Radio2_RxGain_RF-1)*15; |
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295 | fprintf('\nRSSI dBm = %5.2f\n',RSSI_dBm) |
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296 | |
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297 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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298 | % 7. Close sockets |
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299 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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300 | pnet('closeall'); |
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