[12] | 1 | // |
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| 2 | // Cognitive radio simulator |
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| 3 | // |
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| 4 | |
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| 5 | #include <stdio.h> |
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| 6 | #include <stdlib.h> |
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| 7 | #include <math.h> |
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| 8 | #include <sigprocc/sigprocc.h> |
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[26] | 9 | #include "cbr.h" |
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[12] | 10 | #include "cognitive_radio_test.h" |
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| 11 | |
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| 12 | // options |
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| 13 | #define PACKET_SIZE 1024 // packet size (number of bits) |
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| 14 | #define NUM_TRIALS 250 // number of epochs |
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| 15 | #define REPORT_TRIALS 10 // print report every so often |
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| 16 | |
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| 17 | int main() { |
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| 18 | // bookkeeping variables and buffers |
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| 19 | unsigned int num_bits=PACKET_SIZE; |
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| 20 | char msg_in[num_bits], msg_out[num_bits]; |
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| 21 | float I[num_bits], Q[num_bits]; |
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| 22 | unsigned int num_symbols, num_bits_out; |
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| 23 | |
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| 24 | float noise_psd = -100.0f; // noise power spectral density |
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| 25 | float noise_power, noise_std; |
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| 26 | |
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| 27 | // quality of service metrics |
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| 28 | unsigned int num_bit_errors; |
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| 29 | float throughput_bps; |
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| 30 | |
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| 31 | // metadata defaults |
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| 32 | struct metadata_t mdt; |
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| 33 | metadata md = &mdt; |
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| 34 | |
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| 35 | md->mod_scheme = MOD_QAM; // MOD_PSK, MOD_QAM, MOD_PAM, MOD_DPSK |
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| 36 | md->mod_bps = 4; // modulation scheme [bits/s] |
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| 37 | md->tx_power_dBW = -3.0f; // transmit power [dBW] |
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| 38 | md->symbol_rate = 250e3f; // symbol rate [symbols/s] |
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| 39 | |
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[26] | 40 | // case-based reasoner |
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| 41 | unsigned int num_cols = 7; |
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| 42 | char * cols[] = { |
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| 43 | "BER", "throughput", |
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| 44 | "mod_scheme", "tx_power", |
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| 45 | "noise_power", "path_loss", |
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| 46 | "utility" |
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| 47 | }; |
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| 48 | float vals[num_cols]; |
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| 49 | vals[0] = 1e-3f; // BER |
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| 50 | vals[1] = 10e3f; // throughput |
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| 51 | vals[2] = 1; // mod_scheme |
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| 52 | vals[3] = -3.0f; // tx_power |
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| 53 | vals[4] = -50.0f; // noise_power |
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| 54 | vals[5] = 125.0f; // path_loss |
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| 55 | vals[6] = 0.762; // utility |
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| 56 | int rc; |
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| 57 | |
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| 58 | // create cbr database/table |
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| 59 | cbr mycbr = cbr_create("ex1", "data", cols, num_cols); |
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| 60 | |
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| 61 | // add row here |
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| 62 | //rc = cbr_add_row(mycbr, cols, vals, num_cols); |
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| 63 | |
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| 64 | // print |
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| 65 | cbr_print(mycbr); |
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| 66 | |
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| 67 | // cbr search setup |
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| 68 | char * search_names[] = {"BER"}; |
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| 69 | int search_ops[] = {LT}; |
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| 70 | float search_vals[] = {30.0f/(float)PACKET_SIZE}; |
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| 71 | float retvals[num_cols]; |
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| 72 | |
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| 73 | |
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[12] | 74 | unsigned int i; |
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| 75 | // generate random message |
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| 76 | for (i=0; i<num_bits; i++) |
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| 77 | msg_in[i] = (char) (rand() % 2); |
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| 78 | |
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| 79 | printf("epoch\tutility\n"); |
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| 80 | printf("-----\t-------\n"); |
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| 81 | for (i=0; i<NUM_TRIALS; i++) { |
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| 82 | // compute internals |
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| 83 | noise_power = noise_psd + 20*log10f(md->symbol_rate); |
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| 84 | noise_std = powf(10.0f, (noise_power - md->tx_power_dBW) / 10.0f) / 2.0f; |
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| 85 | |
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| 86 | // execute transmitter |
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| 87 | execute_tx(md, msg_in, num_bits, I, Q, &num_symbols); |
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| 88 | |
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| 89 | // execute channel |
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| 90 | execute_channel(md, noise_std, I, Q, num_symbols); |
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| 91 | |
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| 92 | // execute receiver |
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| 93 | execute_rx(md, I, Q, num_symbols, msg_out, &num_bits_out); |
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| 94 | |
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| 95 | // |
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| 96 | // *** compute quality of service metrics *** |
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| 97 | // |
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| 98 | |
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| 99 | // count errors, etc. |
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| 100 | num_bit_errors = count_errors(msg_in, msg_out, num_bits); |
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| 101 | throughput_bps = ((float)(md->mod_bps)) * md->symbol_rate; |
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| 102 | |
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| 103 | if ( ((i+1)%REPORT_TRIALS)==0 || (i+1)==NUM_TRIALS) { |
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| 104 | // print results |
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| 105 | printf("%u\t%.2f\terrors:\t%u\t/ %u, power: %.1f dBW, Fs: %.3f kHz\n", |
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| 106 | i+1, 0.0f, num_bit_errors, num_bits, md->tx_power_dBW, md->symbol_rate/1e3 ); |
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| 107 | } |
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| 108 | |
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| 109 | // |
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| 110 | // *** execute cognition here *** |
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| 111 | // |
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| 112 | |
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[26] | 113 | // store result |
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| 114 | vals[0] = (float) num_bit_errors / PACKET_SIZE; // BER |
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| 115 | vals[1] = throughput_bps; |
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| 116 | //vals[2] = // mod_scheme |
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| 117 | vals[3] = md->tx_power_dBW; // tx_power |
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| 118 | vals[6] = md->tx_power_dBW;// utility |
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| 119 | |
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| 120 | rc = cbr_add_row(mycbr, cols, vals, num_cols); |
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| 121 | |
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| 122 | // execute cbr search |
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| 123 | rc = cbr_search(mycbr, search_names, search_ops, search_vals, 1, retvals); |
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| 124 | |
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| 125 | if (rc==0) { |
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| 126 | // no solution found |
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| 127 | md->tx_power_dBW += 0.2f; |
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| 128 | //printf("no solution found\n"); |
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[12] | 129 | } else { |
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[26] | 130 | // set values |
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| 131 | md->tx_power_dBW = retvals[3]; |
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[12] | 132 | } |
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| 133 | |
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| 134 | } |
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| 135 | |
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[26] | 136 | cbr_free(mycbr); |
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| 137 | |
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[12] | 138 | printf("done.\n"); |
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| 139 | return 0; |
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| 140 | } |
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