source: ResearchApps/PHY/WARPLAB/WARPLab7/M_Code_Examples/wl_example_continuous_tx.m

Last change on this file was 4753, checked in by welsh, 8 years ago

Fixing Typo.

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1%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2% wl_example_continuous_tx.m
3%
4%   This example demonstrates continuous transmit feature of WARP nodes.
5%
6% Requirements:
7%     2 WARP nodes (same hardware generation); 1 RF interface each
8%     WARPLab 7.6.0 and higher
9%
10%
11% NOTE:  This example will not work with WARPLab 7.5.x because nodes have the
12%     restriction that Read IQ / Write IQ cannot occur while transmitting or
13%     receiving.
14%
15%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
16
17clear;
18
19%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
20% Top Level Control Variables
21%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
22
23NUM_RECEPTIONS     = 4;                     % Number of times to capture and plot the Tx waveform
24
25TX_LEN             = 400;                   % Transmission length (in samples).
26                                            %     See documentation for 'continuous_tx' in the baseband buffers documentation for
27                                            %     more information on the restrictions on transmission length:
28                                            %         http://warpproject.org/trac/wiki/WARPLab/Reference/Baseband/Buffers#continuous_tx
29
30RX_LEN             = TX_LEN * 4;            % Reception length (in samples). 
31                                            %     Setting this to a default of 4x the transmission length so that it is easy to see the
32                                            %     repetition of the TX waveform when using continuous tx mode.
33                                            %
34                                            %     NOTE:  Be careful to not exceed the maximum number of samples when using larger
35                                            %         transmission lengths.
36
37
38
39%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
40% Set up the WARPLab experiment
41%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
42
43% Create a vector of node objects
44nodes = wl_initNodes(2);
45
46% Set up transmit and receive nodes
47%     Transmit from nodes(1) to nodes(2)
48node_tx = nodes(1);
49node_rx = nodes(2);
50
51
52%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
53% Set up Trigger Manager
54%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
55
56% Create a UDP broadcast trigger and tell each node to be ready for it
57eth_trig = wl_trigger_eth_udp_broadcast;
58wl_triggerManagerCmd(nodes, 'add_ethernet_trigger', [eth_trig]);
59
60% Read Trigger IDs into workspace
61trig_in_ids  = wl_getTriggerInputIDs(nodes(1));
62trig_out_ids = wl_getTriggerOutputIDs(nodes(1));
63
64% For both nodes, we will allow Ethernet to trigger the baseband buffers
65wl_triggerManagerCmd(nodes, 'output_config_input_selection', [trig_out_ids.BASEBAND], [trig_in_ids.ETH_A]);
66
67
68%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
69% Set up the Interface parameters
70%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
71
72% Get IDs for the interfaces on the boards. 
73%
74% NOTE:  This example assumes each board has the same interface capabilities (ie 2 RF
75%   interfaces; RFA and RFB).  Therefore, we only need to get the IDs from one of the boards.
76%
77ifc_ids = wl_getInterfaceIDs(nodes(1));
78
79% Set the Transmit and Receive interfaces
80%     Transmit from RFA of one node to RFA of the other node
81%
82% NOTE:  Variables are used to make it easier to change interfaces.
83%
84rf_tx         = ifc_ids.RF_A;                    % Transmit RF interface
85rf_rx         = ifc_ids.RF_A;                    % Receive RF interface
86rf_rx_name    = 'RFA';                           % RF interface string used for plots
87
88rf_tx_vec     = ifc_ids.RF_A;                    % Vector version of transmit RF interface
89rf_rx_vec     = ifc_ids.RF_A;                    % Vector version of receive RF interface
90
91% Set the RF center frequency on all interfaces
92%     - Frequency Band  :  Must be 2.4 or 5, to select 2.4GHz or 5GHz channels
93%     - Channel         :  Must be an integer in [1,11] for BAND = 2.4; [1,23] for BAND = 5
94%
95wl_interfaceCmd(nodes, ifc_ids.RF_ALL, 'channel', 2.4, 11);
96
97% Set the RX gains on all interfaces
98%     - Rx RF Gain      :  Must be an integer in [1:3]
99%     - Rx Baseband Gain:  Must be an integer in [0:31]
100%
101% NOTE:  The gains may need to be modified depending on your experimental setup
102%
103wl_interfaceCmd(nodes, ifc_ids.RF_ALL, 'rx_gain_mode', 'manual');
104wl_interfaceCmd(nodes, ifc_ids.RF_ALL, 'rx_gains', 1, 15);
105
106% Set the TX gains on all interfaces
107%     - Tx Baseband Gain:  Must be an integer in [0:3] for approx [-5, -3, -1.5, 0]dB baseband gain
108%     - Tx RF Gain      :  Must be an integer in [0:63] for approx [0:31]dB RF gain
109%
110% NOTE:  The gains may need to be modified depending on your experimental setup
111%
112wl_interfaceCmd(nodes, ifc_ids.RF_ALL, 'tx_gains', 3, 30);
113
114
115%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
116% Set up the Baseband parameters
117%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
118
119% Get the sample frequency from the board
120ts      = 1 / (wl_basebandCmd(nodes(1), 'tx_buff_clk_freq'));
121
122% Read the maximum I/Q buffer length. 
123%
124% NOTE:  This example assumes that each board has the same baseband capabilities (ie both nodes are
125%   the same WARP hardware version, for example WARP v3).  This example also assumes that each RF
126%   interface has the same baseband capabilities (ie the max number of TX samples is the same as the
127%   max number of RF samples). Therefore, we only need to read the max I/Q buffer length of node_tx RFA.
128%
129maximum_buffer_len = wl_basebandCmd(node_tx, rf_tx, 'tx_buff_max_num_samples');
130
131% Set the transmission / receptions lengths (in samples)
132%     See WARPLab user guide for maximum length supported by WARP hardware
133%     versions and different WARPLab versions.
134tx_length = TX_LEN;
135rx_length = RX_LEN;
136
137% Check the transmission length
138if (tx_length > maximum_buffer_len) 
139    error('Node supports max transmission length of %d samples.  Requested %d samples.', maximum_buffer_len, tx_length); 
140end
141
142% Check the reception length
143if (rx_length > maximum_buffer_len) 
144    error('Node supports max transmission length of %d samples.  Requested %d samples.', maximum_buffer_len, rx_length); 
145end
146
147% Set the length for the transmit and receive buffers based on the transmission length
148wl_basebandCmd(nodes, 'tx_length', tx_length);
149wl_basebandCmd(nodes, 'rx_length', rx_length);
150
151
152%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
153% Signal processing to generate transmit signal
154%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
155
156% Create the payload
157t = [0:ts:((tx_length - 1) * ts)].';                                      % Create time vector(Sample Frequency is ts (Hz))
158
159envelope      = (((tx_length - 1) * ts) - t) ./ ((tx_length - 1) * ts);   % Create a linear envelope from 1 to 0 over the sample length
160
161payload       = envelope .* exp(j*2*pi * 5e6 * t);                        % Waveform:  1 MHz sinusoid multiplied by the envelope
162
163txData        = [payload];                                                % Create the transmit data
164
165
166
167%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
168% Transmit and receive signal using WARPLab
169%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
170
171% Set continuous transmit mode
172%     NOTE:  Change this condition to 'false' to see the same example without continuous transmit mode
173%
174if (true)
175    wl_basebandCmd(node_tx, 'continuous_tx', true);
176else
177    wl_basebandCmd(node_tx, 'continuous_tx', false);
178end
179
180% Transmit IQ data to the TX node
181wl_basebandCmd(node_tx, rf_tx_vec, 'write_IQ', txData);
182
183% Enabled the RF interfaces for TX / RX
184wl_interfaceCmd(node_tx, rf_tx, 'tx_en');
185wl_interfaceCmd(node_rx, rf_rx, 'rx_en');
186
187% Enable the buffers for TX / RX
188wl_basebandCmd(node_tx, rf_tx, 'tx_buff_en');
189wl_basebandCmd(node_rx, rf_rx, 'rx_buff_en');
190
191% Send the Ethernet trigger to start the TX / RX
192eth_trig.send();
193
194% Get the waveform NUM_RECEPTIONS times
195for ii = 1:NUM_RECEPTIONS
196    % Read the IQ data from the RX node
197    rx_iq(:, ii) = wl_basebandCmd(node_rx, rf_rx_vec, 'read_IQ', 0, rx_length);
198   
199    % Send the Ethernet trigger to re-start the RX
200    eth_trig.send();
201   
202    % Pause for a moment to let the node continue to transmit
203    pause(0.11);
204end
205
206% Disable the buffers and RF interfaces for TX / RX
207wl_basebandCmd(nodes, ifc_ids.RF_ALL, 'tx_rx_buff_dis');
208wl_interfaceCmd(nodes, ifc_ids.RF_ALL, 'tx_rx_dis');
209
210
211
212%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
213% Visualize results
214%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
215
216% Plotting variables
217iq_range           = 1;                     % Plots IQ values in the range:  [-iq_range, iq_range]
218
219
220figure(1);clf;
221
222for ii = 1:NUM_RECEPTIONS
223    sprintf('Run %d', ii);
224
225    % Plot IQ Data
226    %
227    ax(2 * ii - 1) = subplot(NUM_RECEPTIONS, 2, (2 * ii - 1));
228    plot(0:(length(rx_iq) - 1), real(rx_iq(:, ii)))
229    xlabel('Sample Index')
230    title(sprintf('Run %d - %s: Received I', ii, rf_rx_name))
231    axis([1 rx_length -iq_range iq_range])
232    grid on
233
234    ax(2 * ii) = subplot(NUM_RECEPTIONS, 2, (2 * ii));
235    plot(0:(length(rx_iq) - 1), imag(rx_iq(:, ii)))
236    xlabel('Sample Index')
237    title(sprintf('Run %d - %s: Received Q', ii, rf_rx_name))
238    axis([1 rx_length -iq_range iq_range])
239    grid on
240end
241
242
243
244%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
245% END
246%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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