@@ -101,8 +101,8 @@ #define AGC_BITS (6) //!< AGC to this bit depth //#define OVERFLOW_LOW (256) //!< Overflow low //#define OVERFLOW_HIGH (1024) //!< Overflow high -#define OVERFLOW_LOW (64) //!< Overflow low -#define OVERFLOW_HIGH (256) //!< Overflow high +#define OVERFLOW_LOW (64) //!< Overflow low +#define OVERFLOW_HIGH (512) //!< Overflow high /*----------------------------------------------------------------------------------------------*/ includes/config.h @@ -110,7 +110,7 @@ void Parse_Arguments(int32 argc, char* argv[]) gopt.mode = 0; //!< Single board L1 mode by default gopt.decimate = 16; //!< Default to work with both 65.536 and 64 MHz clocks gopt.gr = 30; //!< 40 dB of RF gain - gopt.gi = 10; //!< 10 dB of IF gain + gopt.gi = 0; //!< 10 dB of IF gain gopt.f_lo_a = L1 - IF_FREQUENCY; //!< Board A L1 by default gopt.f_ddc_a = 0; //!< no DDC correction gopt.f_lo_b = L2 - IF_FREQUENCY; //!< Board B L2 by default main/init.cpp @@ -50,10 +50,10 @@ plot(A(:,7)) plot(A(:,9)) plot(A(:,8)*0.5) -bl = A(:,end-19:end); - -figure -mesh(bl) -shading interp; +% bl = A(:,end-19:end); +% +% figure +% mesh(bl) +% shading interp; matlab/plot_chan.m @@ -201,18 +201,18 @@ void Channel::Accum(Correlation_S *corr, NCO_Command_S *_feedback) I_sum20 += corr->I[1] - I_buff[_1ms_epoch]; Q_sum20 += corr->Q[1] - Q_buff[_1ms_epoch]; -// if((I_buff[_1ms_epoch] > 0) != (corr->I[1] > 0)) -// { -// P_buff[_1ms_epoch]++; -// } - /* Buffer storing past 20 1ms accumulations */ I_buff[_1ms_epoch] = corr->I[1]; Q_buff[_1ms_epoch] = corr->Q[1]; + if((I_buff[_1ms_epoch] > 0) != (I_buff[(_1ms_epoch + 19) % 20] > 0)) + { + P_buff[_1ms_epoch]++; + } + /* Lowpass filter */ //P_buff[_1ms_epoch] = (63 * P_buff[_1ms_epoch] + (I_sum20 >> 6) * (I_sum20 >> 6) + (Q_sum20 >> 6)*(Q_sum20 >> 6) + 32) >> 6; - P_buff[_1ms_epoch] = (63 * P_buff[_1ms_epoch] + (I_sum20 >> 6) * (I_sum20 >> 6) + 32) >> 6; + //P_buff[_1ms_epoch] = (63 * P_buff[_1ms_epoch] + (I_sum20 >> 6) * (I_sum20 >> 6) + 32) >> 6; /* Dump accumulation and do tracking according to integration length */ if((_1ms_epoch % len) == 0) @@ -462,11 +462,11 @@ void Channel::PLL() df = dp = 0; - //if(len == 20 || (_1ms_epoch & 0x1)) +// if(bit_lock) // { // /* FLL discriminator */ // dot = I_prev*I[1] + Q_prev*Q[1]; -// cross = -I_prev*Q[1] + Q_prev*I[1]; +// cross = I_prev*Q[1] - Q_prev*I[1]; // // /* No FLL for now */ // if((dot != 0.0) && (cross != 0.0)) @@ -475,7 +475,7 @@ void Channel::PLL() // df /= (TWO_PI * aPLL.t); // } // } -// + // df = 0; /* PLL discriminator */ @@ -526,74 +526,78 @@ void Channel::Epoch() void Channel::BitLock() { int32 power_buff[20]; - int32 new_epoch; - int32 lcv; - int32 thresh; - uint32 best_sum; + int32 lcv, new_epoch; + int32 thresh_high, thresh_low, bit_lock_err; /* Set bitlock threshold */ - thresh = 1000; + thresh_high = 100; + thresh_low = 25; - if(_1ms_epoch == 19 && (bit_lock_ticks >= thresh)) + if(_1ms_epoch == 19) { if(bit_lock == false) { /* Find the maximum of the power buffer */ - best_sum = 0; new_epoch = 0; + bit_lock_err = 0; new_epoch = 0; for(lcv = 0; lcv < 20; lcv++) { - if(P_buff[lcv] > best_sum) + if(P_buff[lcv] > thresh_high) { - best_sum = P_buff[lcv]; + bit_lock = true; new_epoch = lcv; } - } - /* If the epoch has changed */ - if(new_epoch != best_epoch) - { - bit_lock_ticks = 0; - best_epoch = new_epoch; + if(P_buff[lcv] > thresh_low) + { + bit_lock_err++; + } } - /* If the epoch has NOT changed in X ms */ - if(bit_lock_ticks > thresh) + /* Bin counter exceeded threshold */ + if(bit_lock == true) { - bit_lock = true; - - _1ms_epoch = (38 - best_epoch) % 20; - + best_epoch = 19; bit_lock_pend = 1; - bit_lock_ticks = 0; + _1ms_epoch = (38 - new_epoch) % 20; /* Copy over the power buffer to put the max in element 19 */ for(lcv = 0 ; lcv < 20; lcv++) power_buff[lcv] = P_buff[lcv]; for(lcv = 0 ; lcv < 20; lcv++) - P_buff[lcv] = power_buff[(lcv + best_epoch + 1) % 20]; + P_buff[lcv] = power_buff[(lcv + new_epoch + 1) % 20]; + } + + /* Bit lock failure, reset! */ + if(bit_lock_err > 1) + { + best_epoch = 0; + bit_lock_ticks = 0; + bit_lock = false; + frame_lock = false; + for(lcv = 0 ; lcv < 20; lcv++) + P_buff[lcv] = 0; } + } else if(bit_lock_ticks < 60000) /* Bitlock obtained, keep monitoring it up to 1 minute */ { - /* Find the maximum of the power buffer */ - best_sum = 0; new_epoch = 0; + bit_lock_err = 0; new_epoch = 0; for(lcv = 0; lcv < 20; lcv++) { - if(P_buff[lcv] > best_sum) + if(P_buff[lcv] > bit_lock_err) { - best_sum = P_buff[lcv]; + bit_lock_err = P_buff[lcv]; new_epoch = lcv; } } - best_epoch = new_epoch; - /* Best epoch not in the correct place! */ - if(best_epoch != 19) + if(new_epoch != 19) { + best_epoch = 0; bit_lock_ticks = 0; bit_lock = false; frame_lock = false; @@ -603,8 +607,8 @@ void Channel::BitLock() } } - /* Always do this */ bit_lock_ticks++; + } /*----------------------------------------------------------------------------------------------*/ objects/channel.cpp 72a7faba1770aae88aa7d690d3cc99bef8df18f1 gpssim gpssim@gpsdevc.(none) http://github.com/gps-sdr/gps-sdr/commit/1bee82b19151a808ad75fa0774e8bc56bfba3056 1bee82b19151a808ad75fa0774e8bc56bfba3056 2009-08-05T07:05:52-07:00 2009-08-05T07:05:52-07:00 Changed bitlock algorithm. GN3S and USRP now produce the same noise power. d3cb6453d0cbf7836791bf770d3c3ec8753efd71 gpssim gpssim@gpsdevc.(none)