diff options
Diffstat (limited to 'main.cpp')
| -rw-r--r-- | main.cpp | 111 |
1 files changed, 74 insertions, 37 deletions
@@ -62,26 +62,33 @@ struct CorrelationResult { CorrelationResult(size_t len) : correlation(len), rx_power(0), - tx_power(0) {} + tx_power(0), + rx_timestamp(0), + tx_timestamp(0) {} std::vector<complexf> correlation; double rx_power; double tx_power; + + double rx_timestamp; + double tx_timestamp; }; class AlignSample { public: AlignSample() { - m_rx_sample_time = 0; - m_tx_sample_time = 0; + m_first_rx_sample_time = 0; + m_first_tx_sample_time = 0; + m_num_rx_samples_dropped = 0; + m_num_tx_samples_dropped = 0; } void push_tx_samples(complexf* samps, size_t len, double first_sample_time) { std::lock_guard<std::mutex> lock(m_mutex); std::copy(samps, samps + len, std::back_inserter(m_txsamples)); - if (m_tx_sample_time == 0) { - m_tx_sample_time = first_sample_time; + if (m_first_tx_sample_time == 0) { + m_first_tx_sample_time = first_sample_time; } } @@ -89,41 +96,53 @@ class AlignSample { std::lock_guard<std::mutex> lock(m_mutex); std::copy(samps, samps + len, std::back_inserter(m_rxsamples)); - if (m_rx_sample_time == 0) { - m_rx_sample_time = first_sample_time; + if (m_first_rx_sample_time == 0) { + m_first_rx_sample_time = first_sample_time; } } - bool ready() { + bool ready(size_t min_samples) { std::lock_guard<std::mutex> lock(m_mutex); - return aligned() and m_rxsamples.size() > 8000 and m_txsamples.size() > 8000; + return align() and m_rxsamples.size() > min_samples and m_txsamples.size() > min_samples; } void debug() { + std::lock_guard<std::mutex> lock(m_mutex); MDEBUG("Aligner\n"); - MDEBUG(" RX: %f %zu\n", m_rx_sample_time, m_rxsamples.size()); - MDEBUG(" TX: %f %zu\n", m_tx_sample_time, m_txsamples.size()); + MDEBUG(" RX: %f %zu\n", m_rx_sample_time(), m_rxsamples.size()); + MDEBUG(" TX: %f %zu\n", m_tx_sample_time(), m_txsamples.size()); } CorrelationResult crosscorrelate(size_t max_offset, size_t len) { std::vector<complexf> rxsamps; std::vector<complexf> txsamps; + double rx_ts = 0; + double tx_ts = 0; // Do a quick copy, so as to free the mutex { std::lock_guard<std::mutex> lock(m_mutex); - if (m_rxsamples.size() < len or - m_txsamples.size() < len + max_offset) { + if (!align() or + m_rxsamples.size() < len or + m_txsamples.size() < len + max_offset) { CorrelationResult result(0); return result; } std::copy(m_rxsamples.begin(), m_rxsamples.begin() + len, std::back_inserter(rxsamps)); std::copy(m_txsamples.begin(), m_txsamples.begin() + len + max_offset, std::back_inserter(txsamps)); + + m_rxsamples.erase(m_rxsamples.begin(), m_rxsamples.begin() + len); + m_txsamples.erase(m_txsamples.begin(), m_txsamples.begin() + len + max_offset); + + rx_ts = m_rx_sample_time(); + tx_ts = m_tx_sample_time(); } CorrelationResult result(max_offset); + result.rx_timestamp = rx_ts; + result.tx_timestamp = tx_ts; auto& xcorrs = result.correlation; @@ -154,50 +173,60 @@ class AlignSample { void consume(size_t samples) { std::lock_guard<std::mutex> lock(m_mutex); - if (aligned() and m_rxsamples.size() > samples and m_txsamples.size() > samples) { + if (align() and m_rxsamples.size() > samples and m_txsamples.size() > samples) { m_rxsamples.erase(m_rxsamples.begin(), m_rxsamples.begin() + samples); - m_rx_sample_time += (double)samples / samplerate; + m_num_rx_samples_dropped += samples; m_txsamples.erase(m_txsamples.begin(), m_txsamples.begin() + samples); - m_tx_sample_time += (double)samples / samplerate; + m_num_tx_samples_dropped += samples; } } private: - bool aligned() { - if (std::abs(m_rx_sample_time - m_tx_sample_time) < 1e-6) { + bool align() { + if (std::abs(m_rx_sample_time() - m_tx_sample_time()) < 1e-6) { return true; } - else if (m_rx_sample_time < m_tx_sample_time) { - size_t rx_samples_to_skip = (m_tx_sample_time - m_rx_sample_time) * samplerate; + else if (m_rx_sample_time() < m_tx_sample_time()) { + size_t rx_samples_to_skip = (m_tx_sample_time() - m_rx_sample_time()) * samplerate; if (rx_samples_to_skip > m_rxsamples.size()) { return false; } m_rxsamples.erase(m_rxsamples.begin(), m_rxsamples.begin() + rx_samples_to_skip); - m_rx_sample_time += (double)rx_samples_to_skip / samplerate; + m_num_rx_samples_dropped += rx_samples_to_skip; return true; } - else if (m_rx_sample_time > m_tx_sample_time) { - size_t tx_samples_to_skip = (m_rx_sample_time - m_tx_sample_time) * samplerate; + else if (m_rx_sample_time() > m_tx_sample_time()) { + size_t tx_samples_to_skip = (m_rx_sample_time() - m_tx_sample_time()) * samplerate; if (tx_samples_to_skip > m_txsamples.size()) { return false; } m_txsamples.erase(m_txsamples.begin(), m_txsamples.begin() + tx_samples_to_skip); - m_tx_sample_time += (double)tx_samples_to_skip / samplerate; + m_num_tx_samples_dropped += tx_samples_to_skip; return true; } return false; } + double m_rx_sample_time() { + return m_first_rx_sample_time + (double)m_num_rx_samples_dropped / samplerate; + } + + double m_tx_sample_time() { + return m_first_tx_sample_time + (double)m_num_tx_samples_dropped / samplerate; + } + std::mutex m_mutex; - double m_rx_sample_time; + double m_first_rx_sample_time; + size_t m_num_rx_samples_dropped; std::deque<complexf> m_rxsamples; - double m_tx_sample_time; + double m_first_tx_sample_time; + size_t m_num_tx_samples_dropped; std::deque<complexf> m_txsamples; }; @@ -229,10 +258,12 @@ size_t do_receive(OutputUHD* output_uhd) void find_peak_correlation() { + FILE* fd = fopen("correlation.debug", "w"); + while (running) { - if (aligner.ready()) { - const size_t max_offset = 100000; // 48ms at 2048000 - const size_t correlation_length = 100; + const size_t max_offset = 10000; // 4.8ms at 2048000 + if (aligner.ready(max_offset)) { + const size_t correlation_length = 1000; std::vector<complexf> correlations(max_offset); double max_norm = 0.0; size_t pos_max = 0; @@ -240,28 +271,37 @@ void find_peak_correlation() auto result = aligner.crosscorrelate(max_offset, correlation_length); auto& xcs = result.correlation; + fprintf(fd, "Max correlation is %f at %fms, with RX %fdB and TX %fdB, RXtime %f, TXtime %f\n", + std::sqrt(max_norm), + (double)pos_max / (double)samplerate * 1000.0, + 10*std::log(result.rx_power), + 10*std::log(result.tx_power), + result.rx_timestamp, + result.tx_timestamp); // Find correlation peak for (size_t offset = 0; offset < xcs.size(); offset++) { complexf xc = xcs[offset]; + fprintf(fd, "%f ", std::norm(xc)); if (std::norm(xc) >= max_norm) { max_norm = std::norm(xc); pos_max = offset; } } - MDEBUG("Max correlation is %f at %zu, with RX %fdB and TX %fdB\n", + fprintf(fd, "\n"); + MDEBUG("Max correlation is %f at %fms, with RX %fdB and TX %fdB, RXtime %f, TXtime %f\n", std::sqrt(max_norm), - pos_max, + (double)pos_max / (double)samplerate * 1000.0, 10*std::log(result.rx_power), - 10*std::log(result.tx_power)); + 10*std::log(result.tx_power), + result.rx_timestamp, + result.tx_timestamp); std::this_thread::sleep_for(std::chrono::microseconds(1)); // Eat much more than we correlate, because correlation is slow aligner.consume(2048000); - aligner.debug(); } else { MDEBUG("Waiting for correlation\n"); - aligner.debug(); std::this_thread::sleep_for(std::chrono::seconds(1)); } } @@ -289,9 +329,6 @@ int main(int argc, char **argv) } } - MDEBUG("TX Gain is %f\n", txgain); - MDEBUG("RX Gain is %f\n", rxgain); - if (argc < 2) { MDEBUG("Require input file or url\n"); return -1; |