kopia lustrzana https://github.com/rpp0/gr-lora
Autocorr preamble detection
Pieter Robyns
rodzic
7b2bbb5efe
commit
c45f156267
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@ -1,13 +1,13 @@
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-------- Test Results on 2017-08-23 17:39:53 ---------
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-------- Test Results on 2017-08-23 17:51:40 ---------
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Test serie 0: [u'01 23 45 67 89 ab cd ef'] * 10
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Test 1 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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Test 2 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 9 out of 10 ( 90.00%)
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Test 2 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 8 out of 10 ( 80.00%)
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Test 3 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 4 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 5 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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Test 5 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 9 out of 10 ( 90.00%)
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Test 6 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 7 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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=> Total passed: 39 out of 70 (55.71%)
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Test 7 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 8 out of 10 ( 80.00%)
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=> Total passed: 35 out of 70 (50.00%)
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Test serie 1: [u'11 11 11'] * 1
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Test 8 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 1 out of 1 (100.00%)
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@ -23,21 +23,21 @@ Test serie 2: [u'11 11 11'] * 5
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Test 15 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 16 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 17 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 1 out of 5 ( 20.00%)
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Test 18 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 3 out of 5 ( 60.00%)
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Test 18 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 4 out of 5 ( 80.00%)
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Test 19 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 20 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 1 out of 5 ( 20.00%)
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Test 20 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 2 out of 5 ( 40.00%)
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Test 21 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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=> Total passed: 25 out of 35 (71.43%)
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=> Total passed: 27 out of 35 (77.14%)
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Test serie 3: [u'aa aa aa aa'] * 3
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Test 22 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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Test 23 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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Test 24 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 0 out of 3 ( 0.00%)
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Test 25 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 2 out of 3 ( 66.67%)
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Test 25 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 1 out of 3 ( 33.33%)
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Test 26 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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Test 27 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 0 out of 3 ( 0.00%)
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Test 28 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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=> Total passed: 14 out of 21 (66.67%)
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=> Total passed: 13 out of 21 (61.90%)
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Test serie 4: [u'ff ff ff ff'] * 1
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Test 29 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 1 out of 1 (100.00%)
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@ -64,10 +64,10 @@ Test serie 6: [u'55 55 55 55'] * 3
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Test 44 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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Test 45 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 0 out of 3 ( 0.00%)
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Test 46 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 0 out of 3 ( 0.00%)
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Test 47 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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Test 47 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 2 out of 3 ( 66.67%)
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Test 48 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 0 out of 3 ( 0.00%)
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Test 49 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 3 out of 3 (100.00%)
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=> Total passed: 12 out of 21 (57.14%)
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=> Total passed: 11 out of 21 (52.38%)
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Test serie 7: [u'55 55 55 55'] * 10
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Test 50 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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@ -90,25 +90,25 @@ Test serie 8: [u'88 88 88 88'] * 1
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=> Total passed: 4 out of 7 (57.14%)
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Test serie 9: [u'88 88 88 88'] * 5
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Test 64 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 65 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 64 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 4 out of 5 ( 80.00%)
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Test 65 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 4 out of 5 ( 80.00%)
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Test 66 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 0 out of 5 ( 0.00%)
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Test 67 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 0 out of 5 ( 0.00%)
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Test 67 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 2 out of 5 ( 40.00%)
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Test 68 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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Test 69 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 0 out of 5 ( 0.00%)
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Test 69 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 1 out of 5 ( 20.00%)
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Test 70 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 5 out of 5 (100.00%)
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=> Total passed: 20 out of 35 (57.14%)
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=> Total passed: 21 out of 35 (60.00%)
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Test serie 10: [u'88 88 88 88'] * 10
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Test 71 :: cr4-5 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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Test 72 :: cr4-5 bw125 sf8 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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Test 73 :: cr4-5 bw125 sf12 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 74 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 75 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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Test 74 :: cr4-7 bw125 sf6 crc1 pwr1 :: passed 5 out of 10 ( 50.00%)
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Test 75 :: cr4-7 bw125 sf7 crc1 pwr1 :: passed 9 out of 10 ( 90.00%)
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Test 76 :: cr4-6 bw125 sf6 crc1 pwr1 :: passed 0 out of 10 ( 0.00%)
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Test 77 :: cr4-6 bw125 sf7 crc1 pwr1 :: passed 10 out of 10 (100.00%)
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=> Total passed: 40 out of 70 (57.14%)
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=> Total passed: 44 out of 70 (62.86%)
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====== Total passed: 239 out of 413 (57.87%) ======
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====== Total passed: 240 out of 413 (58.11%) ======
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@ -362,6 +362,27 @@ namespace gr {
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d_fine_sync = -lag;
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}
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float decoder_impl::detect_preamble_autocorr(const gr_complex *samples, const uint32_t window) {
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const gr_complex* chirp1 = samples;
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const gr_complex* chirp2 = samples + d_samples_per_symbol;
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float magsq_chirp1[window];
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float magsq_chirp2[window];
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float energy_chirp1 = 0;
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float energy_chirp2 = 0;
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float autocorr = 0;
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gr_complex dot_product;
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volk_32fc_x2_conjugate_dot_prod_32fc(&dot_product, chirp1, chirp2, window);
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volk_32fc_magnitude_squared_32f(magsq_chirp1, chirp1, window);
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volk_32fc_magnitude_squared_32f(magsq_chirp2, chirp2, window);
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volk_32f_accumulator_s32f(&energy_chirp1, magsq_chirp1, window);
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volk_32f_accumulator_s32f(&energy_chirp2, magsq_chirp2, window);
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autocorr = abs(dot_product / gr_complex(sqrt(energy_chirp1 * energy_chirp2), 0));
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return autocorr;
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}
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float decoder_impl::detect_downchirp(const gr_complex *samples, const uint32_t window) {
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float samples_ifreq[window];
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this->instantaneous_frequency(samples, samples_ifreq, window);
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@ -369,55 +390,24 @@ namespace gr {
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return this->cross_correlate_ifreq(samples_ifreq, this->d_downchirp_ifreq, window - 1u);
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}
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/**
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* 1. Skip through the window and look for a falling edge
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* 2. Get the upper and lower bound of the upchrip edge, or the local maximum and minimum
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* 3. Look for the highest cross correlation index between these points and return
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*/
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float decoder_impl::sliding_norm_cross_correlate_upchirp(const float *samples_ifreq, const uint32_t window, int32_t *index) {
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bool found_change = false;
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uint32_t local_max_idx = 0u, local_min_idx;
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float decoder_impl::sliding_norm_cross_correlate_upchirp(const float *samples_ifreq, const uint32_t window, int32_t *index) {
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float max_correlation = 0;
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const uint32_t coeff = (this->d_sf + this->d_sf + this->d_sf / 2u);
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const uint32_t len = this->d_samples_per_symbol - 1u;
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// Cross correlate
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for (uint32_t i = 0; i < window; i++) {
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const float max_corr = this->cross_correlate_ifreq_fast(samples_ifreq + i, &this->d_upchirp_ifreq[0], window - 1u);
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float max_correlation = 0.0f;
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if (max_corr > max_correlation) {
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*index = i;
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max_correlation = max_corr;
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}
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}
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// Approximate local maximum
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for (uint32_t i = 0u; i < window - coeff - 1u; i += coeff / 2u) {
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if (samples_ifreq[i] - samples_ifreq[i + coeff] > 0.2f) { // Goes down
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local_max_idx = i;
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found_change = true;
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break;
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}
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}
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// Signal from local_max_idx vs shifted with *index
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//DBGR_WRITE_SIGNAL(this->d_upchirp_ifreq, (samples_ifreq + local_max_idx), len, (*index - local_max_idx), 0u, window, false, true, Printed graphs in sliding_norm_cross_correlate_upchirp);
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if (!found_change) {
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//printf("No falling edge?\n");
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return 0.0f;
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}
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// Find top and bottom of falling edge after first upchirp in window
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local_max_idx = std::max_element(samples_ifreq + gr::lora::clamp((int)(local_max_idx - 2u * coeff), 0, (int)window),
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samples_ifreq + gr::lora::clamp(local_max_idx + coeff, 0u, window)) - samples_ifreq;
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local_min_idx = std::min_element(samples_ifreq + gr::lora::clamp(local_max_idx + 1u, 0u, window),
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samples_ifreq + gr::lora::clamp(local_max_idx + 3u * coeff, 0u, window)) - samples_ifreq;
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// Cross correlate between start and end of falling edge instead of entire window
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for (uint32_t i = local_max_idx; i < local_min_idx && (i + len) < window; i++) {
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const float max_corr = this->cross_correlate_ifreq(samples_ifreq + i, this->d_upchirp_ifreq, len);
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if (max_corr > max_correlation) {
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*index = i;
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max_correlation = max_corr;
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}
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}
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// Signal from local_max_idx vs shifted with *index
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//DBGR_WRITE_SIGNAL(this->d_upchirp_ifreq, (samples_ifreq + local_max_idx), len, (*index - local_max_idx), 0u, window, false, true, Printed graphs in sliding_norm_cross_correlate_upchirp);
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return max_correlation;
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}
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return max_correlation;
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}
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/**
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* Slide the given chirp perfectly on top of the ideal upchirp (phase shift).
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@ -453,8 +443,8 @@ namespace gr {
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}
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float decoder_impl::detect_upchirp(const gr_complex *samples, const uint32_t window, int32_t *index) {
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float samples_ifreq[window];
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this->instantaneous_frequency(samples, samples_ifreq, window);
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float samples_ifreq[window*2];
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this->instantaneous_frequency(samples, samples_ifreq, window*2);
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return this->sliding_norm_cross_correlate_upchirp(samples_ifreq, window, index);
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}
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@ -826,39 +816,34 @@ namespace gr {
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switch (this->d_state) {
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case gr::lora::DecoderState::DETECT: {
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const int i = this->find_preamble_start_fast(input);
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//int i = this->find_preamble_start(&input[0]);
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//int i = this->calc_energy_threshold(&input[0], 2u * this->d_samples_per_symbol, this->d_energy_threshold);
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float correlation = detect_preamble_autocorr(input, d_samples_per_symbol);
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if (i != -1) {
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int32_t index_correction = 0;
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const float c = this->detect_upchirp(&input[i],
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this->d_samples_per_symbol * 2u,
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&index_correction);
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if (c > 0.9f) {
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#ifndef NDEBUG
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this->d_debug << "Cu: " << c << std::endl;
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#endif
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this->samples_to_file("/tmp/detectb", &input[i], this->d_samples_per_symbol, sizeof(gr_complex));
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this->samples_to_file("/tmp/detect", &input[i + index_correction], this->d_samples_per_symbol, sizeof(gr_complex));
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this->d_corr_fails = 0u;
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this->d_state = gr::lora::DecoderState::SYNC;
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this->consume_each(i + index_correction);
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break;
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}
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// Consume just 1 symbol after preamble to have more chances to sync later
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this->consume_each(i + this->d_samples_per_symbol);
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} else {
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// Consume 2 symbols (usual) to skip noise faster before preamble has been found
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this->consume_each(2u * this->d_samples_per_symbol);
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if (correlation >= 0.95f) {
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this->samples_to_file("/tmp/detect", &input[0], this->d_samples_per_symbol, sizeof(gr_complex));
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this->d_corr_fails = 0u;
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this->d_state = gr::lora::DecoderState::SYNC;
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break;
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}
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this->consume_each(this->d_samples_per_symbol);
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break;
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}
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case gr::lora::DecoderState::SYNC: {
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int i = 0;
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float correlation = detect_upchirp(input, d_samples_per_symbol, &i);
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#ifndef NDEBUG
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this->d_debug << "Cu: " << correlation << std::endl;
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#endif
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this->consume_each(i);
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this->d_state = gr::lora::DecoderState::FIND_SFD;
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break;
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}
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case gr::lora::DecoderState::FIND_SFD: {
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const float c = this->detect_downchirp(input, this->d_samples_per_symbol);
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#ifndef NDEBUG
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@ -40,6 +40,7 @@ namespace gr {
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enum class DecoderState {
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DETECT,
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SYNC,
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FIND_SFD,
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PAUSE,
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DECODE_HEADER,
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DECODE_PAYLOAD,
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@ -120,6 +121,7 @@ namespace gr {
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float cross_correlate_ifreq_fast(const float *samples_ifreq, const float *ideal_chirp, const uint32_t window);
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void fine_sync(const gr_complex* in_samples, uint32_t bin_idx);
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int32_t d_fine_sync;
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float detect_preamble_autocorr(const gr_complex *samples, uint32_t window);
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/**
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* \brief Calculates the average energy from the given samples and returns whether its higher than the given threshold.
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