[L] Change in osmo-trx[master]: ms: restructure the va code to add rach support

25 Jul 2023

Hoernchen has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-trx/+/33928 )
Change subject: ms: restructure the va code to add rach support
......................................................................
ms: restructure the va code to add rach support
Change-Id: I7275a647428661a788646fec10af429fcdcf577e
new bb
Change-Id: I36dbed6394243c8c2b5e14acbade7b1b82d0708c
XX va trials
Change-Id: Id1de531249922315da35d2d01778a7611879fb92
fugg
Change-Id: Ibe5d538e9970e590877d2a901165defa6dc972fe
tx->va needs scaling by 0.1
Change-Id: Ic3cc5748e00584971c4bd509eed7db9d5f09201c
sch
Change-Id: I41fabcdd5b4a5eb8cff4e42676438b0bffa2e1b9
va1
Change-Id: I93ab3cb8f91bf6e496175ae70e5da0323cabe911
xx
Change-Id: I26b5957f80be02df913e31a370e1e7910f4484df
va2
Change-Id: I09d6b560241e6797a533e7f8e68e899c42517baa
va: max elemn fix
max elem returns the first largest element - but the true value is
skewed to the right in our case.
Change-Id: I1de9b7e280d8723ce9876bef20c790383070e958
SDSD
Change-Id: Ie32fc753548583896be9eef486346617ea8b9e88
adsad
Change-Id: I3a9a2569c2057feae196b182f6e812edd08ccfa4
make ubsan happy
Change-Id: Ic6ddfcf826539dd227e76e8054d3f3d777c97d5e
wtf wip
Change-Id: I0f465da6d17bf91f24a68b3ec2075995478b5fad
a bit of channel impulse resp makes it work (?!)
Change-Id: I2ab1d6bdf89a0d950ebe38b1fd5efb9764c9ba4f
shp
Change-Id: I7f936dd22b55145bd182f3b5e51b9c183ab1725f
finally works as intended.. maybe.
Change-Id: I2af965ab20af74b38975c645093626a81b7fdf72
cleanup
Change-Id: If36f15a5f32465ce04113a669e3875dc19c69d6b
cleanup
Change-Id: I1163a6194570cdce93d46e40e4b710ad5239cce7
iomanip
Change-Id: I20453a5381afcf8a7875b6e82805f7e8595163b2
cleanup3
Change-Id: I8e66f2a447984a1fd5a20814eca3ee019ba59717
cleanup3
Change-Id: Ib499fe0a5d42afd9198da96dbcba2a42705bbe73
use short inted burst
Change-Id: I0bc7a7b35da474bce74f8a36834a22d5885bbdbc
add burst dump
Change-Id: I0ca9114b6a02cac7fb628ac47db2554b3ff3b967
cleanup va
Change-Id: I1697925b0f0f36aaa05ee170a9483750611aef5d
all tests
Change-Id: Ie2db803ccb789699cdfaf82e74acba42123d961a
transceiver: add va
This needs slightly shifted rx windows that need to include the
beginning ot the burst.
Change-Id: I64f4f596875434bf3e7201ddbbe58924482f4559
va offset pretty #1
Change-Id: Ibb6d3b351bfd915d4bfc2587c5f5c47d129de360
va pretty #2
Change-Id: I8bd2cb9dbe449324be64d8514593815c0ca24c0b
makeu
Change-Id: I13ccc55a6f5c0438236490bb1e75f93a0e20fe2e
xx mergeme
Change-Id: Id8edf31fe1bf72a2f254e634edc7c12b3bba8833
---
M Transceiver52M/grgsm_vitac/constants.h
M Transceiver52M/grgsm_vitac/grgsm_vitac.cpp
M Transceiver52M/grgsm_vitac/grgsm_vitac.h
M Transceiver52M/ms/ms_rx_lower.cpp
M Transceiver52M/ms/ms_upper.cpp
5 files changed, 251 insertions(+), 96 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-trx refs/changes/28/33928/1

diff --git a/Transceiver52M/grgsm_vitac/constants.h b/Transceiver52M/grgsm_vitac/constants.h
index 07f2290..27bf6f4 100644
--- a/Transceiver52M/grgsm_vitac/constants.h
+++ b/Transceiver52M/grgsm_vitac/constants.h
@@ -38,6 +38,7 @@
 #define STEALING_BIT      1
 #define N_TRAIN_BITS      26
 #define N_SYNC_BITS       64
+#define N_ACCESS_BITS     41
 #define USEFUL_BITS       142  //(2*(DATA_BITS+STEALING_BIT) + N_TRAIN_BITS )
 #define FCCH_BITS         USEFUL_BITS
 #define BURST_SIZE        (USEFUL_BITS+2*TAIL_BITS)
@@ -73,6 +74,12 @@
   0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1
 };
+static const unsigned char ACCESS_BITS [] = {
+ 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1,
+ 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0,
+ 0, 1, 1, 1, 1, 0, 0, 0
+};
+
 const unsigned FCCH_FRAMES[] = { 0, 10, 20, 30, 40 };
 const unsigned SCH_FRAMES[] = { 1, 11, 21, 31, 41 };
diff --git a/Transceiver52M/grgsm_vitac/grgsm_vitac.cpp b/Transceiver52M/grgsm_vitac/grgsm_vitac.cpp
index 836c555..e186a38 100644
--- a/Transceiver52M/grgsm_vitac/grgsm_vitac.cpp
+++ b/Transceiver52M/grgsm_vitac/grgsm_vitac.cpp
@@ -39,13 +39,13 @@
 #include "viterbi_detector.h"
 #include "grgsm_vitac.h"
-//signalVector mChanResp;
+gr_complex d_sync_training_seq[N_ACCESS_BITS]; ///<encoded training sequence of a SCH burst
 gr_complex d_sch_training_seq[N_SYNC_BITS]; ///<encoded training sequence of a SCH burst
 gr_complex d_norm_training_seq[TRAIN_SEQ_NUM][N_TRAIN_BITS]; ///<encoded training sequences of a normal and dummy burst
 const int d_chan_imp_length = CHAN_IMP_RESP_LENGTH;
-void initvita() {
-
+void initvita()
+{
    /**
     * Prepare SCH sequence bits
     *
@@ -53,59 +53,73 @@
     * Burst and two guard periods
     * (one guard period is an arbitrary overlap)
     */
-	gmsk_mapper(SYNC_BITS, N_SYNC_BITS,
-		d_sch_training_seq, gr_complex(0.0, -1.0));
+	gmsk_mapper(SYNC_BITS, N_SYNC_BITS, d_sch_training_seq, gr_complex(0.0, -1.0));
    for (auto &i : d_sch_training_seq)
    	i = conj(i);
+	/* ab */
+	gmsk_mapper(ACCESS_BITS, N_ACCESS_BITS, d_sync_training_seq, gr_complex(0.0, -1.0));
+	for (auto &i : d_sync_training_seq)
+		i = conj(i);
+
    /* Prepare bits of training sequences */
    for (int i = 0; i < TRAIN_SEQ_NUM; i++) {
    	/**
    	 * If first bit of the sequence is 0
    	 * => first symbol is 1, else -1
    	 */
-		gr_complex startpoint = train_seq[i][0] == 0 ?
-			gr_complex(1.0, 0.0) : gr_complex(-1.0, 0.0);
-		gmsk_mapper(train_seq[i], N_TRAIN_BITS,
-			d_norm_training_seq[i], startpoint);
+		gr_complex startpoint = train_seq[i][0] == 0 ? gr_complex(1.0, 0.0) : gr_complex(-1.0, 0.0);
+		gmsk_mapper(train_seq[i], N_TRAIN_BITS, d_norm_training_seq[i], startpoint);
    	for (auto &i : d_norm_training_seq[i])
    		i = conj(i);
    }
-
 }
-MULTI_VER_TARGET_ATTR NO_UBSAN
-void detect_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary)
+template <unsigned int burst_size>
+NO_UBSAN static void detect_burst_generic(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start,
+					  char *output_binary, int ss)
 {
    std::vector<gr_complex> rhh_temp(CHAN_IMP_RESP_LENGTH * d_OSR);
    unsigned int stop_states[2] = { 4, 12 };
-	gr_complex filtered_burst[BURST_SIZE];
+	gr_complex filtered_burst[burst_size];
    gr_complex rhh[CHAN_IMP_RESP_LENGTH];
-	float output[BURST_SIZE];
-	int start_state = 3;
-
-	// if(burst_start < 0 ||burst_start > 10)
-	// 	fprintf(stderr, "bo %d\n", burst_start);
-
-	// burst_start = burst_start >= 0 ? burst_start : 0;
+	float output[burst_size];
+	int start_state = ss;
autocorrelation(chan_imp_resp, &rhh_temp[0], d_chan_imp_length * d_OSR);
    for (int ii = 0; ii < d_chan_imp_length; ii++)
    	rhh[ii] = conj(rhh_temp[ii * d_OSR]);
-	mafi(&input[burst_start], BURST_SIZE, chan_imp_resp,
-		d_chan_imp_length * d_OSR, filtered_burst);
+	mafi(&input[burst_start], burst_size, chan_imp_resp, d_chan_imp_length * d_OSR, filtered_burst);
-	viterbi_detector(filtered_burst, BURST_SIZE, rhh,
-		start_state, stop_states, 2, output);
+	viterbi_detector(filtered_burst, burst_size, rhh, start_state, stop_states, 2, output);
-	for (int i = 0; i < BURST_SIZE; i++)
-		output_binary[i] = output[i] * -127; // pre flip bits!
+	for (int i = 0; i < burst_size; i++)
+		output_binary[i] = (char)(output[i] * -127); // pre flip bits!
 }
-void
-gmsk_mapper(const unsigned char* input,
-	int nitems, gr_complex* gmsk_output, gr_complex start_point)
+NO_UBSAN void detect_burst_nb(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary,
+			      int ss)
+{
+	return detect_burst_generic<BURST_SIZE>(input, chan_imp_resp, burst_start, output_binary, ss);
+}
+NO_UBSAN void detect_burst_access_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start,
+					char *output_binary, int ss)
+{
+	return detect_burst_generic<8 + 41 + 36 + 3>(input, chan_imp_resp, burst_start, output_binary, ss);
+}
+
+NO_UBSAN void detect_burst_nb(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary)
+{
+	return detect_burst_nb(input, chan_imp_resp, burst_start, output_binary, 3);
+}
+NO_UBSAN void detect_burst_access_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start,
+					char *output_binary)
+{
+	return detect_burst_access_burst(input, chan_imp_resp, burst_start, output_binary, 3);
+}
+
+void gmsk_mapper(const unsigned char *input, int nitems, gr_complex *gmsk_output, gr_complex start_point)
 {
    gr_complex j = gr_complex(0.0, 1.0);
    gmsk_output[0] = start_point;
@@ -122,16 +136,13 @@
    	encoded_symbol = current_symbol * previous_symbol;
/* And do GMSK mapping */
-		gmsk_output[i] = j * gr_complex(encoded_symbol, 0.0)
-			* gmsk_output[i - 1];
+		gmsk_output[i] = j * gr_complex(encoded_symbol, 0.0) * gmsk_output[i - 1];
previous_symbol = current_symbol;
    }
 }
-gr_complex
-correlate_sequence(const gr_complex* sequence,
-	int length, const gr_complex* input)
+gr_complex correlate_sequence(const gr_complex *sequence, int length, const gr_complex *input)
 {
    gr_complex result(0.0, 0.0);
@@ -142,9 +153,7 @@
 }
/* Computes autocorrelation for positive arguments */
-inline void
-autocorrelation(const gr_complex* input,
-	gr_complex* out, int nitems)
+inline void autocorrelation(const gr_complex *input, gr_complex *out, int nitems)
 {
    for (int k = nitems - 1; k >= 0; k--) {
    	out[k] = gr_complex(0, 0);
@@ -153,9 +162,7 @@
    }
 }
-inline void
-mafi(const gr_complex* input, int nitems,
-	gr_complex* filter, int filter_length, gr_complex* output)
+inline void mafi(const gr_complex *input, int nitems, gr_complex *filter, int filter_length, gr_complex *output)
 {
    for (int n = 0; n < nitems; n++) {
    	int a = n * d_OSR;
@@ -170,66 +177,45 @@
    }
 }
-int get_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, int search_center, int search_start_pos,
-		      int search_stop_pos, gr_complex *tseq, int tseqlen, float *corr_max)
+int get_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, int search_start_pos, int search_stop_pos,
+		      gr_complex *tseq, int tseqlen, float *corr_max)
 {
-	std::vector<gr_complex> correlation_buffer;
+	const int num_search_windows = search_stop_pos - search_start_pos;
+	const int power_search_window_len = d_chan_imp_length * d_OSR;
    std::vector<float> window_energy_buffer;
    std::vector<float> power_buffer;
+	std::vector<gr_complex> correlation_buffer;
-	for (int ii = search_start_pos; ii < search_stop_pos; ii++) {
-		gr_complex correlation = correlate_sequence(tseq, tseqlen, &input[ii]);
+	power_buffer.reserve(num_search_windows);
+	correlation_buffer.reserve(num_search_windows);
+	window_energy_buffer.reserve(num_search_windows);
+
+	for (int ii = 0; ii < num_search_windows; ii++) {
+		gr_complex correlation = correlate_sequence(tseq, tseqlen, &input[search_start_pos + ii]);
    	correlation_buffer.push_back(correlation);
    	power_buffer.push_back(std::pow(abs(correlation), 2));
    }
-	int strongest_corr_nr = max_element(power_buffer.begin(), power_buffer.end()) - power_buffer.begin();
-
    /* Compute window energies */
-	auto window_energy_start_offset = strongest_corr_nr - 6 * d_OSR;
-	window_energy_start_offset = window_energy_start_offset < 0 ? 0 : window_energy_start_offset; //can end up out of range..
-	auto window_energy_end_offset = strongest_corr_nr + 6 * d_OSR + d_chan_imp_length * d_OSR;
-	auto iter = power_buffer.begin() + window_energy_start_offset;
-	auto iter_end = power_buffer.begin() + window_energy_end_offset;
-	while (iter != iter_end) {
-		std::vector<float>::iterator iter_ii = iter;
-		bool loop_end = false;
-		float energy = 0;
+	float windowSum = 0;
-		int len = d_chan_imp_length * d_OSR;
-		for (int ii = 0; ii < len; ii++, iter_ii++) {
-			if (iter_ii == power_buffer.end()) {
-				loop_end = true;
-				break;
-			}
+	// first window
+	for (int i = 0; i < power_search_window_len; i++) {
+		windowSum += power_buffer[i];
+	}
+	window_energy_buffer.push_back(windowSum);
-			energy += (*iter_ii);
-		}
-
-		if (loop_end)
-			break;
-
-		window_energy_buffer.push_back(energy);
-		iter++;
+	// slide windows
+	for (int i = power_search_window_len; i < num_search_windows; i++) {
+		windowSum += power_buffer[i] - power_buffer[i - power_search_window_len];
+		window_energy_buffer.push_back(windowSum);
    }
-	/* Calculate the strongest window number */
-	int strongest_window_nr = window_energy_start_offset +
-				  max_element(window_energy_buffer.begin(), window_energy_buffer.end()) -
+	int strongest_window_nr = std::max_element(window_energy_buffer.begin(), window_energy_buffer.end()) -
    			  window_energy_buffer.begin();
-	// auto window_search_start = window_energy_buffer.begin() + strongest_corr_nr - 5* d_OSR;
-	// auto window_search_end = window_energy_buffer.begin() + strongest_corr_nr + 10* d_OSR;
-	// window_search_end = window_search_end >= window_energy_buffer.end() ? window_energy_buffer.end() : window_search_end;
-
-	// /* Calculate the strongest window number */
-	// int strongest_window_nr = max_element(window_search_start, window_search_end /* - d_chan_imp_length * d_OSR*/) - window_energy_buffer.begin();
-
-	// if (strongest_window_nr < 0)
-	// 	strongest_window_nr = 0;
-
    float max_correlation = 0;
-	for (int ii = 0; ii < d_chan_imp_length * d_OSR; ii++) {
+	for (int ii = 0; ii < power_search_window_len; ii++) {
    	gr_complex correlation = correlation_buffer[strongest_window_nr + ii];
    	if (abs(correlation) > max_correlation)
    		max_correlation = abs(correlation);
@@ -242,7 +228,27 @@
     * Compute first sample position, which corresponds
     * to the first sample of the impulse response
     */
-	return search_start_pos + strongest_window_nr - search_center * d_OSR;
+	return search_start_pos + strongest_window_nr;
+}
+
+/*
+8 ext tail bits
+41 sync seq
+36 encrypted bits
+3 tail bits
+68.25 extended tail bits (!)
+
+center at 8+5 (actually known tb -> known isi, start at 8?) FIXME
+*/
+int get_access_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, float *corr_max, int max_delay)
+{
+	const int search_center = 8 + 5;
+	const int search_start_pos = (search_center - 5) * d_OSR + 1;
+	const int search_stop_pos = (search_center + 5 + d_chan_imp_length + max_delay) * d_OSR;
+	const auto tseq = &d_sync_training_seq[TRAIN_BEGINNING];
+	const auto tseqlen = N_ACCESS_BITS - (2 * TRAIN_BEGINNING);
+	return get_chan_imp_resp(input, chan_imp_resp, search_start_pos, search_stop_pos, tseq, tseqlen, corr_max) -
+	       search_center * d_OSR;
 }
/*
@@ -260,8 +266,8 @@
    const int search_stop_pos = (search_center + 5 + d_chan_imp_length) * d_OSR;
    const auto tseq = &d_norm_training_seq[bcc][TRAIN_BEGINNING];
    const auto tseqlen = N_TRAIN_BITS - (2 * TRAIN_BEGINNING);
-	return get_chan_imp_resp(input, chan_imp_resp, search_center, search_start_pos, search_stop_pos, tseq, tseqlen,
-				 corr_max);
+	return get_chan_imp_resp(input, chan_imp_resp, search_start_pos, search_stop_pos, tseq, tseqlen, corr_max) -
+	       search_center * d_OSR;
 }
/*
@@ -281,8 +287,9 @@
// strongest_window_nr + chan_imp_resp_center + SYNC_POS *d_OSR - 48 * d_OSR - 2 * d_OSR + 2 ;
    float corr_max;
-	return get_chan_imp_resp(input, chan_imp_resp, search_center, search_start_pos, search_stop_pos, tseq, tseqlen,
-				 &corr_max);
+	return get_chan_imp_resp(input, chan_imp_resp, search_start_pos, search_stop_pos, tseq, tseqlen, &corr_max) -
+	       search_center * d_OSR;
+	;
 }
int get_sch_buffer_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, unsigned int len, float *corr_max)
@@ -291,9 +298,9 @@
    const int search_center = SYNC_POS + TRAIN_BEGINNING;
    const int search_start_pos = 0;
    // FIXME: proper end offset
-	const int search_stop_pos = len - (N_SYNC_BITS*8);
+	const int search_stop_pos = len - (N_SYNC_BITS * 8);
    auto tseq = &d_sch_training_seq[TRAIN_BEGINNING];
-	return get_chan_imp_resp(input, chan_imp_resp, search_center, search_start_pos, search_stop_pos, tseq, tseqlen,
-				 corr_max);
+	return get_chan_imp_resp(input, chan_imp_resp, search_start_pos, search_stop_pos, tseq, tseqlen, corr_max) -
+	       search_center * d_OSR;
 }
\ No newline at end of file
diff --git a/Transceiver52M/grgsm_vitac/grgsm_vitac.h b/Transceiver52M/grgsm_vitac/grgsm_vitac.h
index 2c89d8c..9d4c300 100644
--- a/Transceiver52M/grgsm_vitac/grgsm_vitac.h
+++ b/Transceiver52M/grgsm_vitac/grgsm_vitac.h
@@ -58,8 +58,13 @@
 int process_vita_burst(gr_complex *input, int tsc, unsigned char *output_binary);
 int process_vita_sc_burst(gr_complex *input, int tsc, unsigned char *output_binary, int *offset);
-MULTI_VER_TARGET_ATTR_CLANGONLY
-void detect_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary);
+void detect_burst_nb(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary, int ss);
+void detect_burst_access_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary,
+			       int ss);
+void detect_burst_nb(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start, char *output_binary);
+void detect_burst_access_burst(const gr_complex *input, gr_complex *chan_imp_resp, int burst_start,
+			       char *output_binary);
+
 void gmsk_mapper(const unsigned char *input, int nitems, gr_complex *gmsk_output, gr_complex start_point);
 gr_complex correlate_sequence(const gr_complex *sequence, int length, const gr_complex *input);
 inline void autocorrelation(const gr_complex *input, gr_complex *out, int nitems);
@@ -67,6 +72,7 @@
 int get_sch_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp);
 int get_norm_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, float *corr_max, int bcc);
 int get_sch_buffer_chan_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, unsigned int len, float *corr_max);
+int get_access_imp_resp(const gr_complex *input, gr_complex *chan_imp_resp, float *corr_max, int max_delay);
enum class btype { NB, SCH };
 struct fdata {
diff --git a/Transceiver52M/ms/ms_rx_lower.cpp b/Transceiver52M/ms/ms_rx_lower.cpp
index 5a07df5..c2adda3 100644
--- a/Transceiver52M/ms/ms_rx_lower.cpp
+++ b/Transceiver52M/ms/ms_rx_lower.cpp
@@ -170,7 +170,7 @@
    	start = start < 39 ? start : 39;
    	start = start > -39 ? start : -39;
    }
-	detect_burst(&ss[start], &channel_imp_resp[0], 0, sch_demod_bits);
+	detect_burst_nb(&ss[start], &channel_imp_resp[0], 0, sch_demod_bits);
auto sch_decode_success = decode_sch(sch_demod_bits, is_first_sch_acq);
diff --git a/Transceiver52M/ms/ms_upper.cpp b/Transceiver52M/ms/ms_upper.cpp
index 21f70bb..6a83f2a 100644
--- a/Transceiver52M/ms/ms_upper.cpp
+++ b/Transceiver52M/ms/ms_upper.cpp
@@ -196,7 +196,7 @@
    	// fprintf(stderr, "%s %d\n", (is_nb ? "N":"D"), burst_time.FN());
    	// if (is_nb)
 #endif
-		detect_burst(ss, &chan_imp_resp[0], normal_burst_start, demodded_softbits);
+		detect_burst_nb(ss, &chan_imp_resp[0], normal_burst_start, demodded_softbits);
 #ifdef DBGXX
    	// else
    	// 	detect_burst(ss, &chan_imp_resp2[0], dummy_burst_start, outbin);
-- 
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Gerrit-Project: osmo-trx
Gerrit-Branch: master
Gerrit-Change-Id: Id8edf31fe1bf72a2f254e634edc7c12b3bba8833
Gerrit-Change-Number: 33928
Gerrit-PatchSet: 1
Gerrit-Owner: Hoernchen ewild@sysmocom.de
Gerrit-MessageType: newchange



    

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[L] Change in osmo-trx[master]: ms: restructure the va code to add rach support