ms: add demod test tool and data

It just uses the viterbi equalizer and the sigproclib to generate and
demodulate bursts and prints the bits, only useful for
development.

Change-Id: I852e34d9667d1f12f235f8b3da1fcc0d738b2db9

8 files changed, 553 insertions, 0 deletions

diff --git a/.checkpatch.conf b/.checkpatch.conf
index 1e4b479..1699801 100644
--- a/.checkpatch.conf
+++ b/.checkpatch.conf
@@ -1,4 +1,5 @@
 --exclude osmocom-bb/.*
 --exclude .*h
 --exclude Transceiver52M/grgsm_vitac/.*
+--exclude utils/va-test/.*
 --ignore FUNCTION_WITHOUT_ARGS
\ No newline at end of file
diff --git a/.gitignore b/.gitignore
index 0b33e0f..581b08f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -83,6 +83,7 @@ contrib/osmo-trx.spec
 !contrib/osmo-trx.spec.in
 
 utils/osmo-prbs-tool
+utils/va-test/osmo-burst-gen
 /.qtc_clangd/*
 /.cache/*
 /.vscode/*
diff --git a/configure.ac b/configure.ac
index 69055fd..8aecb27 100644
--- a/configure.ac
+++ b/configure.ac
@@ -374,6 +374,7 @@ AC_CONFIG_FILES([\
     tests/CommonLibs/Makefile \
     tests/Transceiver52M/Makefile \
     utils/Makefile \
+    utils/va-test/Makefile \
     doc/Makefile \
     doc/examples/Makefile \
     contrib/Makefile \
diff --git a/utils/Makefile.am b/utils/Makefile.am
index bac9a7f..1818093 100644
--- a/utils/Makefile.am
+++ b/utils/Makefile.am
@@ -1,6 +1,8 @@
 AM_CPPFLAGS = $(LIBOSMOCODING_CFLAGS)
 AM_CFLAGS = -Wall
 
+DIST_SUBDIRS = va-test
+
 EXTRA_DIST = clockdump.sh matlab
 
 noinst_PROGRAMS = osmo-prbs-tool
diff --git a/utils/va-test/Makefile.am b/utils/va-test/Makefile.am
new file mode 100644
index 0000000..d5a72e5
--- /dev/null
+++ b/utils/va-test/Makefile.am
@@ -0,0 +1,17 @@
+include $(top_srcdir)/Makefile.common
+
+noinst_PROGRAMS = osmo-burst-gen
+
+osmo_burst_gen_SOURCES = burst-gen.cpp \
+	${top_srcdir}/Transceiver52M/grgsm_vitac/grgsm_vitac.cpp \
+	${top_srcdir}/Transceiver52M/grgsm_vitac/viterbi_detector.cc
+osmo_burst_gen_LDADD = \
+	${top_srcdir}/Transceiver52M/libtransceiver_common.la \
+	$(ARCH_LA) \
+	$(GSM_LA) \
+	$(COMMON_LA)
+osmo_burst_gen_CPPFLAGS = -Wall $(STD_DEFINES_AND_INCLUDES) \
+	-I${top_srcdir}/Transceiver52M/arch/common \
+	-I${top_srcdir}/Transceiver52M/device/common \
+	-I${top_srcdir}/Transceiver52M
+
diff --git a/utils/va-test/burst-gen.cpp b/utils/va-test/burst-gen.cpp
new file mode 100644
index 0000000..bdd0c4b
--- /dev/null
+++ b/utils/va-test/burst-gen.cpp
@@ -0,0 +1,531 @@
+/*
+ * (C) 2023 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Eric Wild <ewild@sysmocom.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+// this allows messing with the demod to check the detecton offset impact,
+// not intended for actual automated tests.
+
+#include "sigProcLib.h"
+
+extern "C" {
+#include "convert.h"
+#include <convolve.h>
+}
+
+#define _CRT_SECURE_NO_WARNINGS
+#include <algorithm>
+#include <string.h>
+#include <iomanip>
+#include <numeric>
+#include <memory>
+#include <iostream>
+#include <fstream>
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <grgsm_vitac/grgsm_vitac.h>
+
+#define DO_RACH
+
+const int SAMPLE_SCALE_FACTOR = 1;
+
+template <typename DST_T, typename SRC_T, typename ST>
+void convert_and_scale(void *dst, void *src, unsigned int src_len, ST scale)
+{
+	for (unsigned int i = 0; i < src_len; i++)
+		reinterpret_cast<DST_T *>(dst)[i] = static_cast<DST_T>((reinterpret_cast<SRC_T *>(src)[i]) * scale);
+}
+template <typename DST_T, typename SRC_T>
+void convert_and_scale_default(void *dst, void *src, unsigned int src_len)
+{
+	return convert_and_scale<DST_T, SRC_T>(dst, src, src_len, SAMPLE_SCALE_FACTOR);
+}
+
+static const unsigned int txFullScale = (float)(1 << 14) - 1;
+// static const unsigned int rxFullScale = (float)(1 << 14) - 1;
+
+static const BitVector
+	gRACHBurstx("0011101001001011011111111001100110101010001111000110111101111110000111001001010110011000");
+
+static const BitVector gTrainingSequencex[] = {
+	BitVector("00100101110000100010010111"), BitVector("00101101110111100010110111"),
+	BitVector("01000011101110100100001110"), BitVector("01000111101101000100011110"),
+	BitVector("00011010111001000001101011"), BitVector("01001110101100000100111010"),
+	BitVector("10100111110110001010011111"), BitVector("11101111000100101110111100"),
+};
+
+struct mrv {
+	std::vector<char> bits;
+	signalVector *rvbuf;
+	std::unique_ptr<std::vector<std::complex<float>>> convolved;
+	// mrv(): bits(), demod_bits() {}
+	CorrType ct;
+};
+
+static mrv genRandNormalBurstx(int tsc, int sps, int tn)
+{
+	mrv retstruct;
+	int i = 0;
+	BitVector bits(148);
+
+	/* Tail bits */
+	for (; i < 3; i++)
+		bits[i] = 0;
+
+	/* Random bits */
+	for (int j = 0; i < 60; i++, j++)
+		bits[i] = rand() % 2;
+
+	/* Stealing bit */
+	bits[i++] = 0;
+
+	/* Training sequence */
+	for (int n = 0; i < 87; i++, n++)
+		bits[i] = gTrainingSequencex[tsc][n];
+
+	/* Stealing bit */
+	bits[i++] = 0;
+
+	/* Random bits */
+	for (; i < 145; i++)
+		bits[i] = rand() % 2;
+
+	/* Tail bits */
+	for (; i < 148; i++)
+		bits[i] = 0;
+
+	int guard = 8 + !(tn % 4);
+	auto r = modulateBurst(bits, guard, sps);
+
+	retstruct.rvbuf = r;
+	for (size_t i = 0; i < bits.size(); i++)
+		retstruct.bits.push_back(bits.bit(i) ? 1 : 0);
+	return retstruct;
+}
+
+static mrv genRandAccessBurstx(int delay, int sps, int tn)
+{
+	mrv retstruct;
+	int i = 0;
+	BitVector bits(88 + delay);
+
+	/* delay */
+	for (; i < delay; i++)
+		bits[i] = 0;
+
+	/* head and synch bits */
+	for (int n = 0; i < 49 + delay; i++, n++)
+		bits[i] = gRACHBurstx[n];
+
+	/* Random bits */
+	for (int j = 0; i < 85 + delay; i++, j++)
+		bits[i] = rand() % 2;
+
+	for (; i < 88 + delay; i++)
+		bits[i] = 0;
+
+	int guard = 68 - delay + !(tn % 4);
+	auto r = modulateBurst(bits, guard, sps);
+
+	retstruct.rvbuf = r;
+	for (size_t i = 0; i < bits.size(); i++)
+		retstruct.bits.push_back(bits.bit(i) ? 1 : 0);
+	return retstruct;
+}
+
+extern gr_complex d_acc_training_seq[N_ACCESS_BITS]; ///<encoded training sequence of a SCH burst
+extern gr_complex d_sch_training_seq[N_SYNC_BITS]; ///<encoded training sequence of a SCH burst
+extern gr_complex d_norm_training_seq[TRAIN_SEQ_NUM]
+				     [N_TRAIN_BITS]; ///<encoded training sequences of a normal and dummy burst
+
+void sv_write_helper(signalVector *burst, std::string fname)
+{
+	auto start = burst->begin();
+	auto n = burst->bytes();
+	char *data = reinterpret_cast<char *>(start);
+
+	const int len_in_real = burst->size() * 2;
+	auto cvrtbuf_tx_a = new int16_t[len_in_real];
+	convert_float_short(cvrtbuf_tx_a, (float *)burst->begin(), float(txFullScale), len_in_real);
+
+	std::ofstream fout;
+	fout.open(fname + ".cfile", std::ios::binary | std::ios::out);
+	fout.write(data, n);
+	fout.close();
+
+	fout.open(fname + ".cs16", std::ios::binary | std::ios::out);
+	fout.write((char *)cvrtbuf_tx_a, len_in_real * sizeof(uint16_t));
+	fout.close();
+	delete[] cvrtbuf_tx_a;
+}
+
+// borrowed from a real world burst..
+static std::vector<std::complex<float>> chan_im_resp = {
+	{ 4.1588e-05 + -0.000361925 },	{ 0.000112728 + -0.000289796 }, { 0.000162952 + -0.000169028 },
+	{ 0.000174185 + -2.54575e-05 }, { 0.000142947 + 0.000105992 },	{ 8.65919e-05 + 0.000187041 },
+	{ 4.15799e-05 + 0.000184346 },	{ 5.30207e-05 + 7.84921e-05 },	{ 0.000158877 + -0.000128058 },
+	{ 0.000373956 + -0.000407954 }, { 0.000680606 + -0.000712065 }, { 0.00102929 + -0.000979604 },
+	{ 0.00135049 + -0.00115333 },	{ 0.00157434 + -0.0011948 },	{ 0.00165098 + -0.00109534 },
+	{ 0.00156519 + -0.000878794 },	{ 0.0013399 + -0.000594285 },	{ 0.00102788 + -0.00030189 },
+	{ 0.000694684 + -5.58912e-05 }, { 0.000399328 + 0.000109463 }
+};
+
+// as above, downsampled to 1sps + just magnitude
+static std::vector<float> chan_im_resp_trunc = { 1., 0.20513351, 0.10020305, 0.11490235 };
+
+template <typename A, typename B>
+auto conv(const std::vector<A> &a, const std::vector<B> &b) -> std::unique_ptr<std::vector<A>>
+{
+	int data_len = a.size();
+	int conv_len = b.size();
+	int conv_size = conv_len + data_len - 1;
+	auto retv = std::make_unique<std::vector<A>>(conv_size);
+
+	for (int i = 0; i < data_len; ++i) {
+		for (int j = 0; j < conv_len; ++j) {
+			(*retv)[i + j] += a[i] * b[j];
+		}
+	}
+	return retv;
+}
+
+template <typename A>
+static auto conv(const A *a, int len, std::vector<float> &b)
+{
+	std::vector<A> aa(len);
+	std::copy_n(a, len, aa.begin());
+	std::reverse(b.begin(), b.end());
+	return conv(aa, b);
+}
+template <typename A>
+static auto conv(const A *a, int len, std::vector<A> &b)
+{
+	std::vector<A> aa(len);
+	std::copy_n(a, len, aa.begin());
+	std::reverse(b.begin(), b.end());
+	return conv(aa, b);
+}
+
+// signalvector is owning despite claiming not to, but we can pretend, too..
+static void dummy_free(void *wData){};
+static void *dummy_alloc(size_t newSize)
+{
+	return 0;
+};
+
+template <typename T>
+size_t read_from_file(std::string path, std::vector<T> &outvec)
+{
+	std::ifstream infile;
+	infile.open(path, std::ios::in | std::ios::binary);
+	if (infile.fail()) {
+		std::cout << " not found: " << path << std::endl;
+		exit(0);
+	}
+	infile.seekg(0, std::ios_base::end);
+	size_t fsize = infile.tellg();
+	auto fsize_in_T = fsize / sizeof(T);
+	infile.seekg(0, std::ios_base::beg);
+
+	outvec.resize(fsize_in_T);
+	infile.read(reinterpret_cast<char *>(&outvec[0]), fsize);
+	infile.close();
+	std::cout << "Read " << fsize << " from " << path << std::endl;
+	return fsize;
+}
+void demod_real_burst(int num = 0)
+{
+	auto path = "./nb_chunk_tsc7.cfile";
+	auto bitfile = "./demodbits_tsc7.s8";
+
+	std::vector<std::complex<float>> burstdata;
+	std::vector<char> bitdata;
+	read_from_file(path, burstdata);
+	read_from_file(bitfile, bitdata);
+
+	// print "known good" burst bits
+	std::cerr << "known bits:" << std::endl;
+	std::cerr << std::setw(5) << 0 << " - ";
+	for (auto i : bitdata)
+		std::cout << (i > 0 ? "1" : "0");
+	std::cerr << std::endl;
+	std::cerr << "demod tests sigproclib:" << std::endl;
+
+	auto ct = CorrType::TSC;
+	auto delay = 0;
+	auto tsc = 7;
+	int offset = 0;
+	auto cplx = reinterpret_cast<complex *>(&burstdata[offset]);
+	auto stdcplx = reinterpret_cast<std::complex<float> *>(&burstdata[offset]);
+	signalVector sv(&cplx[0], 0, burstdata.size() - offset, dummy_alloc, dummy_free);
+
+	struct estim_burst_params ebp;
+	auto rc = detectAnyBurst(sv, tsc, BURST_THRESH, 4, ct, 40, &ebp);
+
+	auto rxBurst = std::unique_ptr<SoftVector>(demodAnyBurst(sv, (CorrType)rc, 4, &ebp));
+	// print osmotrx sigproclib demod result
+	std::cerr << std::setw(5) << int(ebp.toa) << " o ";
+	for (ssize_t i = 0 + delay; i < 148 + delay; i++)
+		std::cout << (rxBurst->bit(i) ? "1" : "0");
+	std::cerr << std::endl;
+
+	std::cerr << "demod test va:" << std::endl;
+	std::complex<float> chan_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR];
+	float ncmax;
+	char demodded_softbits[444];
+
+	// demod at known offset
+	{
+		auto inp = &stdcplx[29]; // known offset
+		auto normal_burst_startX = get_norm_chan_imp_resp(inp, &chan_imp_resp[0], &ncmax, tsc);
+		detect_burst_nb(inp, &chan_imp_resp[0], normal_burst_startX, demodded_softbits);
+
+		std::cerr << std::setw(5) << normal_burst_startX << " v ";
+		for (size_t i = 0; i < 148; i++)
+			std::cerr << (demodded_softbits[i] < 0 ? "1" : "0");
+		std::cerr << std::endl;
+	}
+	{
+		std::cerr << "-- va start offset loop --" << std::endl;
+		std::cerr << "offset/det offset/#errors/known^demod bits" << std::endl;
+		for (int i = 0; i < 34; i++) {
+			auto inp = &stdcplx[i];
+			auto conved_beg = inp;
+
+			auto me = get_norm_chan_imp_resp(conved_beg, &chan_imp_resp[0], &ncmax, tsc);
+			detect_burst_nb(conved_beg, &chan_imp_resp[0], me, demodded_softbits);
+			auto bitdiffarr = std::make_unique<char[]>(148);
+			for (size_t i = 0; i < 148; i++)
+				bitdiffarr.get()[i] = (demodded_softbits[i] < 0 ? 1 : 0) ^ (bitdata[i] > 0 ? 1 : 0);
+			auto ber = std::accumulate(bitdiffarr.get(), bitdiffarr.get() + 148, 0);
+
+			std::cerr << std::setw(3) << i << ": " << std::setw(3) << me << " v " << std::setw(3) << ber
+				  << " ";
+			for (size_t i = 0; i < 148; i++)
+				std::cerr << (bitdiffarr[i] ? "1" : "0");
+			std::cerr << std::endl;
+			// std::cerr << std::setw(4) << i << " (" << std::setw(4) << 29 - i << "):" << std::setw(4) << org
+			// 	  << " " << std::setw(4) << me << " y " << std::endl;
+		}
+	}
+}
+
+auto gen_burst(CorrType t, int delay, int tsc)
+{
+	mrv rs;
+	if (t == CorrType::RACH) {
+		rs = genRandAccessBurstx(delay, 4, tsc);
+
+	} else if (t == CorrType::TSC) {
+		rs = genRandNormalBurstx(tsc, 4, 0);
+	} else {
+		std::cerr << "wtf?" << std::endl;
+		exit(0);
+	}
+	rs.ct = t;
+
+	signalVector *burst = rs.rvbuf;
+	// sv_write_helper(burst, std::to_string(num));
+	// scaleVector(*burst, {1, 0});
+	const int len_in_real = burst->size() * 2;
+	auto cvrtbuf_tx_a = std::make_unique<short[]>(len_in_real);
+	auto cvrtbuf_rx_a = std::make_unique<float[]>(len_in_real);
+	auto rx_cfloat = reinterpret_cast<std::complex<float> *>(&cvrtbuf_rx_a[0]);
+
+	convert_float_short(cvrtbuf_tx_a.get(), (float *)burst->begin(), float(txFullScale), len_in_real);
+	convert_short_float(cvrtbuf_rx_a.get(), cvrtbuf_tx_a.get(), len_in_real);
+	for (int i = 0; i < len_in_real; i++) // scale properly!
+		cvrtbuf_rx_a[i] *= 1. / txFullScale;
+	auto conved = conv(rx_cfloat, burst->size(), chan_im_resp);
+
+	std::cerr << "-- generated " << (t == CorrType::RACH ? "RACH" : "TSC") << " burst --" << std::endl;
+	for (size_t i = 0; i < rs.bits.size(); i++)
+		std::cerr << (rs.bits[i] ? "1" : "0");
+	std::cerr << std::endl;
+	delete burst;
+	rs.convolved = std::move(conved);
+	return rs;
+}
+
+void demod_generated_burst(CorrType t)
+{
+	int tsc = 0;
+	int delay = 0;
+	auto rs = gen_burst(t, delay, tsc);
+	auto conved_beg = &(*rs.convolved)[0];
+
+	if (rs.ct == CorrType::RACH) {
+		std::complex<float> chan_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR];
+		float ncmax;
+		char demodded_softbits[444];
+		int normal_burst_start = 0;
+		normal_burst_start = get_access_imp_resp(conved_beg, &chan_imp_resp[0], &ncmax, 0);
+		normal_burst_start = std::max(normal_burst_start, 0);
+		for (int j = 0; j < 4; j++) {
+			for (int start_val = 0; start_val < 16; start_val++) {
+				auto bitdiffarr = std::make_unique<char[]>(rs.bits.size());
+				detect_burst_ab(conved_beg, &chan_imp_resp[0], normal_burst_start + j,
+						demodded_softbits, start_val);
+
+				for (size_t i = 0; i < rs.bits.size(); i++)
+					bitdiffarr.get()[i] = (demodded_softbits[i] < 0 ? 1 : 0) ^ rs.bits[i];
+				auto ber = std::accumulate(bitdiffarr.get(), bitdiffarr.get() + rs.bits.size(), 0);
+
+				std::cerr << "ber " << std::setw(4) << ber << " bo:" << std::setw(4) << j
+					  << " vas:" << std::setw(4) << start_val << " ";
+				// for (size_t i = 0; i < rs.num_bits; i++)
+				// 	std::cerr << (demodded_softbits[i] < 0 ? "1" : "0");
+				// std::cerr << std::endl;
+				// std::cerr << "d " << std::setw(4) << ber << " ";
+				for (size_t i = 0; i < rs.bits.size(); i++)
+					std::cerr << (bitdiffarr.get()[i] ? "1" : "0");
+				std::cerr << std::endl;
+
+				// std::cerr << "v " << std::setw(4) << j << std::setw(4) << start_val << " ";
+				// for (size_t i = 0; i < rs.num_bits; i++)
+				// 	std::cerr << (demodded_softbits[i] < 0 ? "1" : "0");
+				// std::cerr << std::endl;
+				// std::cerr << "d " << std::setw(4) << ber << " ";
+				// for (size_t i = 0; i < rs.num_bits; i++)
+				// 	std::cerr << (ptr.get()[i] ? "1" : "0");
+				// std::cerr << std::endl;
+			}
+		}
+
+	} else {
+		std::complex<float> chan_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR];
+		float ncmax;
+		char demodded_softbits[444];
+
+		auto normal_burst_start = get_norm_chan_imp_resp(conved_beg, &chan_imp_resp[0], &ncmax, tsc);
+		detect_burst_nb(conved_beg, &chan_imp_resp[0], normal_burst_start + 0, demodded_softbits);
+		std::cerr << "toa " << std::setprecision(2) << normal_burst_start << std::endl;
+
+		std::cerr << "vita ";
+		for (size_t i = 0; i < rs.bits.size(); i++)
+			std::cerr << (demodded_softbits[i] < 0 ? "1" : "0");
+		std::cerr << std::endl;
+		std::cerr << "diff ";
+		for (size_t i = 0; i < rs.bits.size(); i++)
+			std::cerr << ((demodded_softbits[i] < 0 ? 1 : 0) ^ rs.bits[i] ? "1" : "0");
+		std::cerr << std::endl;
+	}
+
+	struct estim_burst_params ebp;
+	char demodded_softbits[444];
+	complex *rx_sigproc_cfloat = reinterpret_cast<complex *>(conved_beg);
+	signalVector sv(rx_sigproc_cfloat, 0, rs.convolved->size(), dummy_alloc, dummy_free);
+
+	auto rc = detectAnyBurst(sv, tsc, BURST_THRESH, 4, rs.ct, 40, &ebp);
+	auto rxBurst = std::unique_ptr<SoftVector>(demodAnyBurst(sv, (CorrType)rc, 4, &ebp));
+
+	std::cerr << "toa " << std::setprecision(2) << ebp.toa << std::endl;
+
+	for (ssize_t i = 0; i < delay; i++) // maybe pad rach op?
+		demodded_softbits[i] = 0;
+	for (size_t i = 0 + delay; i < rs.bits.size() + delay; i++)
+		demodded_softbits[i] = (rxBurst->bit(i) ? 1 : 0);
+
+	std::cerr << "sigp ";
+	for (size_t i = 0; i < rs.bits.size(); i++)
+		std::cerr << (demodded_softbits[i] ? "1" : "0");
+	std::cerr << std::endl;
+
+	std::cerr << "diff ";
+	for (size_t i = 0; i < rs.bits.size(); i++)
+		std::cerr << (demodded_softbits[i] ^ rs.bits[i] ? "1" : "0");
+	std::cerr << std::endl;
+}
+
+void demod_test_offsets()
+{
+	const int tsc = 0;
+	const int delaybuffer_realoffset = 100;
+
+	{
+		auto rs = gen_burst(CorrType::RACH, 0, tsc);
+		typeof(*rs.convolved) delay_buffer(rs.convolved->size() * 2); // plenty of space..
+
+		for (int delay = -10; delay < 60; delay++) {
+			std::fill(delay_buffer.begin(), delay_buffer.end(), 0);
+			std::copy(rs.convolved->begin(), rs.convolved->end(),
+				  delay_buffer.begin() + delaybuffer_realoffset + delay);
+
+			auto conved_beg = &delay_buffer[delaybuffer_realoffset];
+
+			std::complex<float> chan_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR];
+			float ncmax;
+			auto va_burst_start = get_access_imp_resp(conved_beg, &chan_imp_resp[0], &ncmax, 60);
+
+			complex *rx_sigproc_cfloat = reinterpret_cast<complex *>(conved_beg);
+			struct estim_burst_params ebp;
+			signalVector sv(rx_sigproc_cfloat, 0, rs.convolved->size(), dummy_alloc, dummy_free);
+			detectAnyBurst(sv, tsc, BURST_THRESH, 4, rs.ct, 60, &ebp);
+			std::cerr << "delay:" << std::setw(3) << std::setprecision(2) << delay;
+			std::cerr << " va: " << std::setw(3) << std::setprecision(2) << va_burst_start;
+			std::cerr << " sg: " << std::setw(3) << std::setprecision(2) << ebp.toa;
+			std::cerr << " d: " << std::setw(3) << std::setprecision(2) << (ebp.toa * 4) - va_burst_start;
+			std::cerr << " ! " << float(va_burst_start + 13) / 4 << std::endl;
+		}
+	}
+	{
+		auto rs = gen_burst(CorrType::TSC, 0, tsc);
+		typeof(*rs.convolved) delay_buffer(rs.convolved->size() * 2); // plenty of space..
+
+		for (int delay = -10; delay < 10; delay++) {
+			std::fill(delay_buffer.begin(), delay_buffer.end(), 0);
+			std::copy(rs.convolved->begin(), rs.convolved->end(),
+				  delay_buffer.begin() + delaybuffer_realoffset + delay);
+
+			auto conved_beg = &delay_buffer[delaybuffer_realoffset];
+
+			std::complex<float> chan_imp_resp[CHAN_IMP_RESP_LENGTH * d_OSR];
+			float ncmax;
+			auto va_burst_start = get_norm_chan_imp_resp(conved_beg, &chan_imp_resp[0], &ncmax, tsc);
+
+			complex *rx_sigproc_cfloat = reinterpret_cast<complex *>(conved_beg);
+			struct estim_burst_params ebp;
+			signalVector sv(rx_sigproc_cfloat, 0, rs.convolved->size(), dummy_alloc, dummy_free);
+			detectAnyBurst(sv, tsc, BURST_THRESH, 4, rs.ct, 60, &ebp);
+			std::cerr << "delay:" << std::setw(3) << std::setprecision(2) << delay;
+			std::cerr << " va: " << std::setw(3) << std::setprecision(2) << va_burst_start;
+			std::cerr << " sg: " << std::setw(3) << std::setprecision(2) << ebp.toa;
+			std::cerr << " d: " << std::setw(3) << std::setprecision(2) << (ebp.toa * 4) - va_burst_start;
+			std::cerr << " ! " << float(va_burst_start + 19) / 4 << std::endl;
+		}
+	}
+}
+
+int main()
+{
+	convolve_init();
+	convert_init();
+	sigProcLibSetup();
+	initvita();
+
+	for (int i = 0; i < 1; i++) {
+		demod_real_burst(i);
+		demod_generated_burst(CorrType::RACH);
+		demod_generated_burst(CorrType::TSC);
+		demod_test_offsets();
+	}
+}
diff --git a/utils/va-test/demodbits_tsc7.s8 b/utils/va-test/demodbits_tsc7.s8
new file mode 100644
index 0000000..c91cd6c
--- /dev/null
+++ b/utils/va-test/demodbits_tsc7.s8
diff --git a/utils/va-test/nb_chunk_tsc7.cfile b/utils/va-test/nb_chunk_tsc7.cfile
new file mode 100644
index 0000000..67e577e
--- /dev/null
+++ b/utils/va-test/nb_chunk_tsc7.cfile