diff options
| -rw-r--r-- | include/osmocom/gmr1/sdr/fcch.h | 26 | ||||
| -rw-r--r-- | src/gmr1_rx.c | 16 | ||||
| -rw-r--r-- | src/sdr/fcch.c | 152 |
3 files changed, 130 insertions, 64 deletions
diff --git a/include/osmocom/gmr1/sdr/fcch.h b/include/osmocom/gmr1/sdr/fcch.h index 4181569..bc617e5 100644 --- a/include/osmocom/gmr1/sdr/fcch.h +++ b/include/osmocom/gmr1/sdr/fcch.h @@ -1,5 +1,5 @@ -/* GMR-1 SDR - FCCH burst */ -/* See GMR-1 05.004 (ETSI TS 101 376-5-4 V1.2.1) - Section 8.1 */ +/* GMR-1 SDR - FCCH bursts */ +/* See GMR-1 05.004 (ETSI TS 101 376-5-4 V3.1.1) - Section 8 */ /* (C) 2011-2016 by Sylvain Munaut <tnt@246tNt.com> * All Rights Reserved @@ -33,19 +33,31 @@ #include <osmocom/dsp/cxvec.h> -#define GMR1_FCCH_SYMS (39*3) /*!< \brief FCCH burst duration in symbols */ +struct gmr1_fcch_burst +{ + float freq; /*!< \brief Frequency sweep range */ + int len; /*!< \brief Burst duration in symbols */ +}; +extern const struct gmr1_fcch_burst gmr1_fcch_burst; +extern const struct gmr1_fcch_burst gmr1_fcch3_lband_burst; +extern const struct gmr1_fcch_burst gmr1_fcch3_sband_burst; -int gmr1_fcch_rough(struct osmo_cxvec *search_win_in, int sps, float freq_shift, + +int gmr1_fcch_rough(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *search_win_in, int sps, float freq_shift, int *toa); -int gmr1_fcch_rough_multi(struct osmo_cxvec *search_win_in, int sps, float freq_shift, +int gmr1_fcch_rough_multi(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *search_win_in, int sps, float freq_shift, int *toa, int N); -int gmr1_fcch_fine(struct osmo_cxvec *burst_in, int sps, float freq_shift, +int gmr1_fcch_fine(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *burst_in, int sps, float freq_shift, int *toa, float *freq_error); -int gmr1_fcch_snr(struct osmo_cxvec *burst_in, int sps, float freq_shift, +int gmr1_fcch_snr(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *burst_in, int sps, float freq_shift, float *snr); diff --git a/src/gmr1_rx.c b/src/gmr1_rx.c index e6e6dba..c0817d6 100644 --- a/src/gmr1_rx.c +++ b/src/gmr1_rx.c @@ -54,6 +54,8 @@ static struct gsmtap_inst *g_gti; +static const struct gmr1_fcch_burst *fcch_type = &gmr1_fcch_burst; + struct tch3_state { /* Status */ @@ -606,7 +608,7 @@ fcch_single_init(struct chan_desc *cd) return rv; } - rv = gmr1_fcch_rough(win, cd->sps, 0.0f, &toa); + rv = gmr1_fcch_rough(fcch_type, win, cd->sps, 0.0f, &toa); if (rv) { fprintf(stderr, "[!] Error during FCCH rough acquisition (%d)\n", rv); return rv; @@ -615,9 +617,9 @@ fcch_single_init(struct chan_desc *cd) cd->align += toa; /* Fine FCCH detection*/ - win_map(win, cd->bcch, cd->align, GMR1_FCCH_SYMS * cd->sps); + win_map(win, cd->bcch, cd->align, fcch_type->len * cd->sps); - rv = gmr1_fcch_fine(win, cd->sps, 0.0f, &toa, &cd->freq_err); + rv = gmr1_fcch_fine(fcch_type, win, cd->sps, 0.0f, &toa, &cd->freq_err); if (rv) { fprintf(stderr, "[!] Error during FCCH fine acquisition (%d)\n", rv); return rv; @@ -642,7 +644,7 @@ fcch_multi_process(struct chan_desc *cd, fcch_multi_cb_t cb) fprintf(stderr, "[+] FCCH multi acquisition\n"); /* Multi FCCH detection (need 650 ms of signals) */ - base_align = cd->align - GMR1_FCCH_SYMS * cd->sps; + base_align = cd->align - fcch_type->len * cd->sps; if (base_align < 0) base_align = 0; @@ -652,7 +654,7 @@ fcch_multi_process(struct chan_desc *cd, fcch_multi_cb_t cb) return rv; } - rv = gmr1_fcch_rough_multi(win, cd->sps, -cd->freq_err, mtoa, 16); + rv = gmr1_fcch_rough_multi(fcch_type, win, cd->sps, -cd->freq_err, mtoa, 16); if (rv < 0) { fprintf(stderr, "[!] Error during FCCH rough mutli-acquisition (%d)\n", rv); return rv; @@ -668,9 +670,9 @@ fcch_multi_process(struct chan_desc *cd, fcch_multi_cb_t cb) int toa; /* Perform fine acquisition */ - win_map(win, cd->bcch, base_align + mtoa[i], GMR1_FCCH_SYMS * cd->sps); + win_map(win, cd->bcch, base_align + mtoa[i], fcch_type->len * cd->sps); - rv = gmr1_fcch_fine(win, cd->sps, -cd->freq_err, &toa, &freq_err); + rv = gmr1_fcch_fine(fcch_type, win, cd->sps, -cd->freq_err, &toa, &freq_err); if (rv) { fprintf(stderr, "[!] Error during FCCH fine acquisition (%d)\n", rv); return rv; diff --git a/src/sdr/fcch.c b/src/sdr/fcch.c index 9cdff94..af87515 100644 --- a/src/sdr/fcch.c +++ b/src/sdr/fcch.c @@ -1,5 +1,5 @@ /* GMR-1 SDR - FCCH bursts */ -/* See GMR-1 05.004 (ETSI TS 101 376-5-4 V1.2.1) - Section 8.1 */ +/* See GMR-1 05.004 (ETSI TS 101 376-5-4 V3.1.1) - Section 8 */ /* (C) 2011-2016 by Sylvain Munaut <tnt@246tNt.com> * All Rights Reserved @@ -41,30 +41,63 @@ /* ------------------------------------------------------------------------ */ +/* Burst format data */ +/* ------------------------------------------------------------------------ */ + +/*! \brief FCCH burst (GMR-1 version) + * See GMR-1 05.004 (ETSI TS 101 376-5-2 V3.1.1) - Section 8.1 + */ +const struct gmr1_fcch_burst gmr1_fcch_burst = { + .freq = 0.32f, + .len = 3 * 39, +}; + + +/*! \brief FCCH3 L-band burst (GMR-1 3G version for L-band) + * See GMR-1 05.004 (ETSI TS 101 376-5-2 V3.1.1) - Section 8.2.1 + */ +const struct gmr1_fcch_burst gmr1_fcch3_lband_burst = { + .freq = 0.32f, + .len = 12 * 39, +}; + +/*! \brief FCCH3 S-band burst (GMR-1 3G version for S-band) + * See GMR-1 05.004 (ETSI TS 101 376-5-2 V3.1.1) - Section 8.2.2 + */ +const struct gmr1_fcch_burst gmr1_fcch3_sband_burst = { + .freq = 0.16f, + .len = 12 * 39, +}; + + +/* ------------------------------------------------------------------------ */ /* Reference waveform generation */ /* ------------------------------------------------------------------------ */ /*! \brief Generate FCCH reference up or down chirp at a given oversampling + * \param[in] burst_type FCCH burst format description * \param[in] sps Oversampling rate * \param[in] up_down Selects chirp direction (0=down 1=up) * \returns A newly allocated complex vector containing the chirp * * Up-Chirp: \f$\frac{\sqrt{2}}{2}\cdot e^{j\left( - * 0.64\pi\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ + * 2\pi f\cdot\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ * * Down-Chirp: \f$\frac{\sqrt{2}}{2}\cdot e^{-j\left( - * 0.64\pi\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ + * 2\pi f\cdot\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ * - * The length will be 117 * sps + * The resulting length will either be 117 * sps or 468 * sps depending on the + * type of FCCH burst */ static struct osmo_cxvec * -gmr1_sdr_fcch_gen_up_down_chirp(int sps, int up_down) +gmr1_sdr_fcch_gen_up_down_chirp(const struct gmr1_fcch_burst *burst_type, + int sps, int up_down) { struct osmo_cxvec *cv; int i, l; float sq2d2, phase_base, pos, halfpos; - l = GMR1_FCCH_SYMS * sps; + l = burst_type->len * sps; cv = osmo_cxvec_alloc(l); if (!cv) @@ -73,8 +106,8 @@ gmr1_sdr_fcch_gen_up_down_chirp(int sps, int up_down) cv->len = l; sq2d2 = sqrtf(2.0f) / 2.0f; - phase_base = 0.64f * M_PIf / (float)(GMR1_FCCH_SYMS); - halfpos = ((float)(GMR1_FCCH_SYMS)) / 2.0f; + phase_base = burst_type->freq * 2.0f * M_PIf / (float)(burst_type->len); + halfpos = ((float)(burst_type->len)) / 2.0f; if (up_down) phase_base *= -1.0f; @@ -88,51 +121,57 @@ gmr1_sdr_fcch_gen_up_down_chirp(int sps, int up_down) } /*! \brief Generate FCCH reference up chirp at a given oversampling + * \param[in] burst_type FCCH burst format description * \param[in] sps Oversampling rate * \returns A newly allocated complex vector containing the chirp * * \f$\frac{\sqrt{2}}{2}\cdot e^{j\left( - * 0.64\pi\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ + * 2\pi f\cdot\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ * - * The length will be 117 * sps + * The resulting length will either be 117 * sps or 468 * sps depending on the + * type of FCCH burst */ static struct osmo_cxvec * -gmr1_sdr_fcch_gen_up_chirp(int sps) +gmr1_sdr_fcch_gen_up_chirp(const struct gmr1_fcch_burst *burst_type, int sps) { - return gmr1_sdr_fcch_gen_up_down_chirp(sps, 0); + return gmr1_sdr_fcch_gen_up_down_chirp(burst_type, sps, 0); } /*! \brief Generate FCCH reference down chirp at a given oversampling + * \param[in] burst_type FCCH burst format description * \param[in] sps Oversampling rate * \returns A newly allocated complex vector containing the chirp * * \f$\frac{\sqrt{2}}{2}\cdot e^{-j\left( - * 0.64\pi\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ + * 2\pi f\cdot\left(t-\frac{T}{2}\right)^2/T^2\right)}\f$ * - * The length will be 117 * sps + * The resulting length will either be 117 * sps or 468 * sps depending on the + * type of FCCH burst */ static struct osmo_cxvec * -gmr1_sdr_fcch_gen_down_chirp(int sps) +gmr1_sdr_fcch_gen_down_chirp(const struct gmr1_fcch_burst *burst_type, int sps) { - return gmr1_sdr_fcch_gen_up_down_chirp(sps, 1); + return gmr1_sdr_fcch_gen_up_down_chirp(burst_type, sps, 1); } /*! \brief Generate FCCH reference dual chirp at a given oversampling + * \param[in] burst_type FCCH burst format description * \param[in] sps Oversampling rate * \returns A newly allocated complex vector containing the dual chirp * - * \f$\sqrt{2}\cdot\cos\left(0.64\pi\left(t-\frac{T}{2}\right)^2/\;T^2\right)\f$ + * \f$\sqrt{2}\cdot\cos\left(2\pi f\cdot\left(t-\frac{T}{2}\right)^2/\;T^2\right)\f$ * - * The length will be 117 * sps. The vector is also 'real only'. + * The resulting length will either be 117 * sps or 468 * sps depending on the + * type of FCCH burst. The vector is also 'real only'. */ static struct osmo_cxvec * -gmr1_sdr_fcch_gen_dual_chirp(int sps) +gmr1_sdr_fcch_gen_dual_chirp(const struct gmr1_fcch_burst *burst_type, int sps) { struct osmo_cxvec *cv; int i, l; float sq2, phase_base, pos, halfpos; - l = GMR1_FCCH_SYMS * sps; + l = burst_type->len * sps; cv = osmo_cxvec_alloc(l); if (!cv) @@ -142,8 +181,8 @@ gmr1_sdr_fcch_gen_dual_chirp(int sps) cv->flags |= CXVEC_FLG_REAL_ONLY; sq2 = sqrtf(2.0f); - phase_base = 0.64f * M_PIf / (float)(GMR1_FCCH_SYMS); - halfpos = ((float)(GMR1_FCCH_SYMS)) / 2.0f; + phase_base = burst_type->freq * 2.0f * M_PIf / (float)(burst_type->len); + halfpos = ((float)(burst_type->len)) / 2.0f; for (i=0; i<l; i++) { pos = ((float)i / (float)sps) - halfpos; @@ -159,6 +198,7 @@ gmr1_sdr_fcch_gen_dual_chirp(int sps) /* ------------------------------------------------------------------------ */ /*! \brief Rough FCCH timing acquisition + * \param[in] burst_type FCCH burst format description * \param[in] search_win_in Complex signal where to search for FCCH * \param[in] sps Oversampling used in the input complex signal * \param[in] freq_shift Frequency shift to pre-apply to search_win_in (rad/sym) @@ -169,7 +209,8 @@ gmr1_sdr_fcch_gen_dual_chirp(int sps) * (so more than 320 ms of signal, plus the fcch length itself) */ int -gmr1_fcch_rough(struct osmo_cxvec *search_win_in, int sps, float freq_shift, +gmr1_fcch_rough(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *search_win_in, int sps, float freq_shift, int *toa) { struct osmo_cxvec *ref = NULL; @@ -179,7 +220,7 @@ gmr1_fcch_rough(struct osmo_cxvec *search_win_in, int sps, float freq_shift, int rv = 0; /* Generate reference dual chirp */ - ref = gmr1_sdr_fcch_gen_dual_chirp(1); + ref = gmr1_sdr_fcch_gen_dual_chirp(burst_type, 1); if (!ref) { rv = -ENOMEM; goto err; @@ -210,6 +251,7 @@ err: /*! \brief Internal method to record peaks in order or power and remove dupes + * \param[in] burst_type FCCH burst format description * \param[in,out] toa Array of TOA already recorded * \param[in,out] pwr Array of pwr already recorded * \param[in,out] n Number of peaks already recorded @@ -220,17 +262,18 @@ err: * \param[in] peak_pwr New peak power */ static inline void -_peak_record(int *toa, float *pwr, int *n, int N, int Lp, int sps, +_peak_record(const struct gmr1_fcch_burst *burst_type, + int *toa, float *pwr, int *n, int N, int Lp, int sps, int peak_toa, float peak_pwr) { int i,j; int has_dupe = 0; /* Make sure it's not a duplicate at Lp interval */ - /* (with a GMR1_FCCH_SYMS / 2 window) */ + /* (with a window of half burst length) */ for (i=0; i<*n; i++) { /* Compute params */ - int th = (GMR1_FCCH_SYMS * sps) >> 1; /* threshold */ + int th = (burst_type->len * sps) >> 1; /* threshold */ int d = (toa[i] % Lp) - (peak_toa % Lp);/* wrapped toa diff */ /* If not a dupe, continue */ @@ -283,6 +326,7 @@ _peak_record(int *toa, float *pwr, int *n, int N, int Lp, int sps, } /*! \brief Rough FCCH timing acquisition w/ multiple FCCH detection + * \param[in] burst_type FCCH burst format description * \param[in] search_win_in Complex signal where to search for FCCH * \param[in] sps Oversampling used in the input complex signal * \param[in] freq_shift Frequency shift to pre-apply to search_win_in (rad/sym) @@ -295,7 +339,8 @@ _peak_record(int *toa, float *pwr, int *n, int N, int Lp, int sps, * plus some margin). */ int -gmr1_fcch_rough_multi(struct osmo_cxvec *search_win_in, int sps, float freq_shift, +gmr1_fcch_rough_multi(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *search_win_in, int sps, float freq_shift, int *peaks_toa, int N) { struct osmo_cxvec *ref = NULL; @@ -311,7 +356,7 @@ gmr1_fcch_rough_multi(struct osmo_cxvec *search_win_in, int sps, float freq_shif return -EINVAL; /* Generate reference dual chirp */ - ref = gmr1_sdr_fcch_gen_dual_chirp(1); + ref = gmr1_sdr_fcch_gen_dual_chirp(burst_type, 1); if (!ref) { rv = -ENOMEM; goto err; @@ -333,7 +378,7 @@ gmr1_fcch_rough_multi(struct osmo_cxvec *search_win_in, int sps, float freq_shif } Lw = (320 * GMR1_SYM_RATE) / 1000; /* Len window */ - Lw += GMR1_FCCH_SYMS; + Lw += burst_type->len; Lp = (320 * GMR1_SYM_RATE) / 1000; /* Len period */ @@ -427,7 +472,7 @@ gmr1_fcch_rough_multi(struct osmo_cxvec *search_win_in, int sps, float freq_shif p_pos = (int)round((i + p_fpos) * sps); /* Record the peak */ - _peak_record( + _peak_record(burst_type, peaks_toa, peaks_pwr, &peaks_cnt, N, Lp, sps, p_pos, p_pwr ); @@ -452,6 +497,7 @@ err: /*! \brief Fine FCCH timing & frequency acquisition + * \param[in] burst_type FCCH burst format description * \param[in] burst_in Complex signal of the FCCH burst * \param[in] sps Oversampling used in the input complex signal * \param[in] freq_shift Frequency shift to pre-apply to burst_in (rad/sym) @@ -459,26 +505,28 @@ err: * \param[out] freq_error Pointer to the frequency error return variable (rad/sym) * \returns 0 in case of success. -errno for errors. * - * The input vector must be GMR1_FCCH_SYMS * sps samples long. + * The input vector must be burst_type->len * sps samples long. * The frequency error is doesn't include any correction done with * freq_shift. */ int -gmr1_fcch_fine(struct osmo_cxvec *burst_in, int sps, float freq_shift, +gmr1_fcch_fine(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *burst_in, int sps, float freq_shift, int *toa, float *freq_error) { struct osmo_cxvec *ref_up = NULL, *ref_down = NULL; struct osmo_cxvec *mix_up = NULL, *mix_down = NULL; struct osmo_cxvec *burst = NULL; fftwf_plan fft_plan; - float peak_up, peak_down; - float freq_err_hz, freq_err_rps, toa_ms, toa_samples; + float bin_hz, peak_up, peak_down; + float freq_err_hz, freq_err_rps; + float chirp_rate, toa_ms, toa_samples; int len, mid, i; int rv = 0; /* Generate reference up & down chirp */ - ref_up = gmr1_sdr_fcch_gen_up_chirp(1); - ref_down = gmr1_sdr_fcch_gen_down_chirp(1); + ref_up = gmr1_sdr_fcch_gen_up_chirp(burst_type, 1); + ref_down = gmr1_sdr_fcch_gen_down_chirp(burst_type, 1); if (!ref_up || !ref_down) { rv = -ENOMEM; @@ -493,7 +541,7 @@ gmr1_fcch_fine(struct osmo_cxvec *burst_in, int sps, float freq_shift, } /* Sanity check */ - len = GMR1_FCCH_SYMS; + len = burst_type->len; if ((len != burst->len) || (len != ref_up->len) || @@ -523,7 +571,7 @@ gmr1_fcch_fine(struct osmo_cxvec *burst_in, int sps, float freq_shift, DEBUG_SIGNAL("fcch_mix_down", mix_down); /* Compute the FFT */ - /* Shift the frequency to center the FFT on x[58] */ + /* Shift the frequency to center the FFT on x[len >> 1] */ mid = (float)(len >> 1); for (i=0; i<len; i++) { float complex fs = cexp(I * 2.0f * M_PIf * mid / (float)(len) * i); @@ -545,22 +593,23 @@ gmr1_fcch_fine(struct osmo_cxvec *burst_in, int sps, float freq_shift, DEBUG_SIGNAL("fcch_fft_down", mix_down); /* Find peaks position */ - peak_up = osmo_cxvec_peak_energy_find(mix_up, 5, PEAK_WEIGH_WIN, NULL); + peak_up = osmo_cxvec_peak_energy_find(mix_up, 5, PEAK_WEIGH_WIN, NULL); peak_down = osmo_cxvec_peak_energy_find(mix_down, 5, PEAK_WEIGH_WIN, NULL); /* Convert to frequencies */ - peak_up = (peak_up - mid) * 200.0f; /* 200 Hz bin size */ - peak_down = (peak_down - mid) * 200.0f; + bin_hz = (float)GMR1_SYM_RATE / (float)len; + peak_up = (peak_up - mid) * bin_hz; + peak_down = (peak_down - mid) * bin_hz; /* Frequency error */ - freq_err_hz = (peak_up + peak_down) / 2; - freq_err_rps = (2 * M_PIf * freq_err_hz) / GMR1_SYM_RATE; + freq_err_hz = (peak_up + peak_down) / 2.0f; + freq_err_rps = (2.0f * M_PIf * freq_err_hz) / GMR1_SYM_RATE; *freq_error = freq_err_rps; /* Time of arrival */ - /* 3 kHz / ms chrip ramp rate */ - toa_ms = ((peak_up - peak_down) / 2) / 3000.0f; + chirp_rate = (2.0f * burst_type->freq * GMR1_SYM_RATE * GMR1_SYM_RATE) / (float)(burst_type->len * 1000); + toa_ms = ((peak_up - peak_down) / 2.0f) / chirp_rate; toa_samples = (toa_ms * GMR1_SYM_RATE * sps) / 1000.0f; *toa = (int)round(toa_samples); @@ -580,18 +629,21 @@ err: /*! \brief SNR estimation on a FCCH burst + * \param[in] burst_type FCCH burst format description * \param[in] burst_in Complex signal of the FCCH burst * \param[in] sps Oversampling used in the input complex signal * \param[in] freq_shift Frequency shift to pre-apply to burst_in (rad/sym) * \param[out] snr Pointer to the SNR return variable * \returns 0 in case of success. -errno for errors. * - * The input vector must be GMR1_FCCH_SYMS * sps samples long. + * The input vector must be burst_type->len * sps samples long. * This method estimated the FFT peak energy over the FFT average energy * to estimate SNR. */ int -gmr1_fcch_snr(struct osmo_cxvec *burst_in, int sps, float freq_shift, float *snr) +gmr1_fcch_snr(const struct gmr1_fcch_burst *burst_type, + struct osmo_cxvec *burst_in, int sps, float freq_shift, + float *snr) { struct osmo_cxvec *ref = NULL; struct osmo_cxvec *burst = NULL; @@ -601,7 +653,7 @@ gmr1_fcch_snr(struct osmo_cxvec *burst_in, int sps, float freq_shift, float *snr int rv = 0; /* Generate reference dual chirp */ - ref = gmr1_sdr_fcch_gen_dual_chirp(1); + ref = gmr1_sdr_fcch_gen_dual_chirp(burst_type, 1); if (!ref) { rv = -ENOMEM; goto err; @@ -615,7 +667,7 @@ gmr1_fcch_snr(struct osmo_cxvec *burst_in, int sps, float freq_shift, float *snr } /* Sanity check */ - len = GMR1_FCCH_SYMS; + len = burst_type->len; if ((len != burst->len) || (len != ref->len)) { |