dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2008 Free Software Foundation, Inc. |
| 3 | * |
| 4 | * This software is distributed under multiple licenses; see the COPYING file in the main directory for licensing information for this specific distribuion. |
| 5 | * |
| 6 | * This use of this software may be subject to additional restrictions. |
| 7 | * See the LEGAL file in the main directory for details. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 12 | |
| 13 | */ |
| 14 | |
kurtis.heimerl | 8aea56e | 2011-11-26 03:18:30 +0000 | [diff] [blame] | 15 | #ifndef SIGPROCLIB_H |
| 16 | #define SIGPROCLIB_H |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 17 | |
| 18 | #include "Vector.h" |
| 19 | #include "Complex.h" |
Alexander Chemeris | d734e2d | 2013-06-16 14:30:58 +0400 | [diff] [blame] | 20 | #include "BitVector.h" |
Thomas Tsou | 20eb6d6 | 2013-11-09 14:30:41 -0500 | [diff] [blame] | 21 | #include "signalVector.h" |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 22 | |
Tom Tsou | b0aefcb | 2016-03-06 03:44:34 -0800 | [diff] [blame] | 23 | /* Burst lengths */ |
Alexander Chemeris | 0229d22 | 2017-03-17 16:03:17 -0700 | [diff] [blame] | 24 | #define NORMAL_BURST_NBITS 148 |
| 25 | #define EDGE_BURST_NBITS 444 |
| 26 | #define EDGE_BURST_NSYMS (EDGE_BURST_NBITS / 3) |
Tom Tsou | b0aefcb | 2016-03-06 03:44:34 -0800 | [diff] [blame] | 27 | |
Alexander Chemeris | f9e78be | 2017-03-17 15:00:34 -0700 | [diff] [blame] | 28 | /** Codes for burst types of received bursts*/ |
| 29 | enum CorrType{ |
| 30 | OFF, ///< timeslot is off |
| 31 | TSC, ///< timeslot should contain a normal burst |
| 32 | RACH, ///< timeslot should contain an access burst |
| 33 | EDGE, ///< timeslot should contain an EDGE burst |
| 34 | IDLE ///< timeslot is an idle (or dummy) burst |
| 35 | }; |
| 36 | |
Alexander Chemeris | 4aa548f | 2017-03-17 15:23:06 -0700 | [diff] [blame] | 37 | enum SignalError { |
Tom Tsou | 577cd02 | 2015-05-18 13:57:54 -0700 | [diff] [blame] | 38 | SIGERR_NONE, |
| 39 | SIGERR_BOUNDS, |
| 40 | SIGERR_CLIP, |
| 41 | SIGERR_UNSUPPORTED, |
| 42 | SIGERR_INTERNAL, |
| 43 | }; |
| 44 | |
Alexander Chemeris | b34e60c | 2017-03-17 15:29:09 -0700 | [diff] [blame] | 45 | /* |
| 46 | * Burst detection threshold |
| 47 | * |
| 48 | * Decision threshold value for burst gating on peak-to-average value of |
| 49 | * correlated synchronization sequences. Lower values pass more bursts up |
| 50 | * to upper layers but will increase the false detection rate. |
| 51 | */ |
| 52 | #define BURST_THRESH 4.0 |
| 53 | |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 54 | /** Setup the signal processing library */ |
Tom Tsou | 2079a3c | 2016-03-06 00:58:56 -0800 | [diff] [blame] | 55 | bool sigProcLibSetup(); |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 56 | |
| 57 | /** Destroy the signal processing library */ |
| 58 | void sigProcLibDestroy(void); |
| 59 | |
Alexander Chemeris | 132fb24 | 2017-03-17 17:22:33 -0700 | [diff] [blame] | 60 | /** Operate soft slicer on a soft-bit vector */ |
| 61 | bool vectorSlicer(SoftVector *x); |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 62 | |
| 63 | /** GMSK modulate a GSM burst of bits */ |
| 64 | signalVector *modulateBurst(const BitVector &wBurst, |
Alexander Chemeris | 0229d22 | 2017-03-17 16:03:17 -0700 | [diff] [blame] | 65 | int guardPeriodLength, |
| 66 | int sps, bool emptyPulse = false); |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 67 | |
Tom Tsou | d325343 | 2016-03-06 03:08:01 -0800 | [diff] [blame] | 68 | /** 8-PSK modulate a burst of bits */ |
| 69 | signalVector *modulateEdgeBurst(const BitVector &bits, |
| 70 | int sps, bool emptyPulse = false); |
| 71 | |
| 72 | /** Generate a EDGE burst with random payload - 4 SPS (625 samples) only */ |
| 73 | signalVector *generateEdgeBurst(int tsc); |
| 74 | |
Tom Tsou | 8ee2f38 | 2016-03-06 20:57:34 -0800 | [diff] [blame] | 75 | /** Generate an empty burst - 4 or 1 SPS */ |
| 76 | signalVector *generateEmptyBurst(int sps, int tn); |
| 77 | |
| 78 | /** Generate a normal GSM burst with random payload - 4 or 1 SPS */ |
| 79 | signalVector *genRandNormalBurst(int tsc, int sps, int tn); |
| 80 | |
Alexander Chemeris | 5efe050 | 2016-03-23 17:06:32 +0300 | [diff] [blame] | 81 | /** Generate an access GSM burst with random payload - 4 or 1 SPS */ |
Alexander Chemeris | 37c52c7 | 2016-03-25 18:28:34 +0300 | [diff] [blame] | 82 | signalVector *genRandAccessBurst(int delay, int sps, int tn); |
Alexander Chemeris | 5efe050 | 2016-03-23 17:06:32 +0300 | [diff] [blame] | 83 | |
Tom Tsou | 8ee2f38 | 2016-03-06 20:57:34 -0800 | [diff] [blame] | 84 | /** Generate a dummy GSM burst - 4 or 1 SPS */ |
| 85 | signalVector *generateDummyBurst(int sps, int tn); |
| 86 | |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 87 | /** |
| 88 | Apply a scalar to a vector. |
| 89 | @param x The vector of interest. |
| 90 | @param scale The scalar. |
| 91 | */ |
| 92 | void scaleVector(signalVector &x, |
Alexander Chemeris | 0229d22 | 2017-03-17 16:03:17 -0700 | [diff] [blame] | 93 | complex scale); |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 94 | |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 95 | /** |
Alexander Chemeris | 1dd05cf | 2017-03-15 23:23:36 +0300 | [diff] [blame] | 96 | Rough energy estimator. |
| 97 | @param rxBurst A GSM burst. |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 98 | @param windowLength The number of burst samples used to compute burst energy |
Alexander Chemeris | 1dd05cf | 2017-03-15 23:23:36 +0300 | [diff] [blame] | 99 | @return The average power of the received burst. |
dburgess | b3a0ca4 | 2011-10-12 07:44:40 +0000 | [diff] [blame] | 100 | */ |
Alexander Chemeris | 1470fcd | 2017-03-17 22:35:02 -0700 | [diff] [blame] | 101 | float energyDetect(const signalVector &rxBurst, |
Alexander Chemeris | 1dd05cf | 2017-03-15 23:23:36 +0300 | [diff] [blame] | 102 | unsigned windowLength); |
Tom Tsou | d325343 | 2016-03-06 03:08:01 -0800 | [diff] [blame] | 103 | /** |
Alexander Chemeris | 4e6c938 | 2017-03-17 15:24:18 -0700 | [diff] [blame] | 104 | 8-PSK/GMSK/RACH burst detector |
| 105 | @param burst The received GSM burst of interest |
| 106 | @param tsc Midamble type (0..7) also known as TSC |
| 107 | @param threshold The threshold that the received burst's post-correlator SNR is compared against to determine validity. |
| 108 | @param sps The number of samples per GSM symbol. |
| 109 | @param amplitude The estimated amplitude of received TSC burst. |
| 110 | @param toa The estimate time-of-arrival of received TSC burst (in symbols). |
| 111 | @param max_toa The maximum expected time-of-arrival (in symbols). |
| 112 | @return positive value (CorrType) if threshold value is reached, |
| 113 | negative value (-SignalError) on error, |
| 114 | zero (SIGERR_NONE) if no burst is detected |
| 115 | */ |
Alexander Chemeris | 1470fcd | 2017-03-17 22:35:02 -0700 | [diff] [blame] | 116 | int detectAnyBurst(const signalVector &burst, |
Alexander Chemeris | 4e6c938 | 2017-03-17 15:24:18 -0700 | [diff] [blame] | 117 | unsigned tsc, |
| 118 | float threshold, |
| 119 | int sps, |
| 120 | CorrType type, |
| 121 | complex &, |
| 122 | float &toa, |
| 123 | unsigned max_toa); |
| 124 | |
Alexander Chemeris | 6e1dffd | 2017-03-17 16:13:51 -0700 | [diff] [blame] | 125 | /** Demodulate burst basde on type and output soft bits */ |
Alexander Chemeris | e0c1218 | 2017-03-18 13:27:48 -0700 | [diff] [blame] | 126 | SoftVector *demodAnyBurst(const signalVector &burst, int sps, |
Alexander Chemeris | 6e1dffd | 2017-03-17 16:13:51 -0700 | [diff] [blame] | 127 | complex amp, float toa, CorrType type); |
| 128 | |
kurtis.heimerl | 8aea56e | 2011-11-26 03:18:30 +0000 | [diff] [blame] | 129 | #endif /* SIGPROCLIB_H */ |