Add layer 1 software loopback test

impl/test/CMakeLists.txt

@@ -12,3 +12,35 @@ target_link_libraries(
 	m
 	liquid
 )
+
+#------------------------------------
+
+add_executable(
+	test_layer1_loopback
+	../src/layer1/correlator.c
+	../src/layer1/correlator.h
+	../src/layer1/freq_est.c
+	../src/layer1/freq_est.h
+	../src/layer1/packet_mod.c
+	../src/layer1/packet_mod.h
+	../src/layer1/preamble.c
+	../src/layer1/preamble.h
+	../src/layer1/transmission.c
+	../src/layer1/transmission.h
+	../src/layer1/tx.c
+	../src/layer1/tx.h
+	../src/layer1/rx.c
+	../src/layer1/rx.h
+	../src/layer1/whitening.c
+	../src/layer1/whitening.h
+	../src/layer1/modcod.c
+	../src/layer1/modcod.h
+	../src/utils.c
+	layer1/test_loopback.c
+)
+
+target_link_libraries(
+	test_layer1_loopback
+	m
+	liquid
+)

impl/test/layer1/test_loopback.c

@@ -0,0 +1,161 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <ctype.h>
+
+#include <liquid/liquid.h>
+
+#include "layer1/tx.h"
+#include "layer1/rx.h"
+
+#include "utils.h"
+
+#include "sdr/sdr.h"
+
+#include "config.h"
+
+#define RESULT_CHECK(stmt) { \
+	result_t res = stmt; \
+	if(res != OK) { \
+		fprintf(stderr, "Error %d in %s:%d!\n", res, __FILE__, __LINE__); \
+		exit(1); \
+	} \
+}
+
+
+void print_complex_array(const char *varname, float complex const *array, size_t len)
+{
+	fprintf(stderr, "%s=np.array([%f%+fj", varname, crealf(array[0]), cimagf(array[0]));
+	for(size_t k = 1; k < len; k++) {
+		fprintf(stderr, ", %f%+fj", crealf(array[k]), cimagf(array[k]));
+	}
+	fprintf(stderr, "])\n");
+}
+
+
+void hexdump(const uint8_t *data, size_t len)
+{
+	static const char lut[16] = "0123456789ABCDEF";
+	static const size_t BYTES_PER_LINE = 16;
+
+	size_t pos = 0;
+
+	while(pos < len) {
+		size_t bytes_in_line = len - pos;
+		if(bytes_in_line > BYTES_PER_LINE) {
+			bytes_in_line = BYTES_PER_LINE;
+		}
+
+		for(size_t i = 0; i < BYTES_PER_LINE; i++) {
+			if(i >= bytes_in_line) {
+				fputs("   ", stderr);
+			} else {
+				uint8_t byte = data[pos+i];
+
+				fprintf(stderr, "%c%c ", lut[byte >> 4], lut[byte & 0x0F]);
+			}
+		}
+
+		fputs("  ", stderr);
+
+		for(size_t i = 0; i < bytes_in_line; i++) {
+			uint8_t byte = data[pos+i];
+
+			if(isprint(byte)) {
+				putc(byte, stderr);
+			} else {
+				putc('.', stderr);
+			}
+		}
+
+		putc('\n', stderr);
+		pos += bytes_in_line;
+	}
+}
+
+
+void cb_rx(rx_evt_t evt, uint8_t *packet_data, size_t packet_len)
+{
+	switch(evt)
+	{
+		case RX_EVT_CHECKSUM_ERROR:
+			fprintf(stderr, "Received a message of %zu bytes, but decoding failed.\n", packet_len);
+			fprintf(stderr, "=== FAILED PAYLOAD ===\n");
+			hexdump(packet_data, packet_len);
+			fprintf(stderr, "=======================\n");
+			break;
+
+		case RX_EVT_PACKET_RECEIVED:
+			fprintf(stderr, "A message of %zu bytes was decoded successfully.\n", packet_len);
+			fprintf(stderr, "=== DECODED PAYLOAD (%4zu bytes) ===\n", packet_len);
+			hexdump(packet_data, packet_len < 64 ? packet_len : 64);
+			fprintf(stderr, "====================================\n");
+			break;
+
+		case RX_EVT_PREAMBLE_FOUND:
+			fprintf(stderr, "Found preamble!\n");
+			break;
+	}
+}
+
+
+int main(void)
+{
+	layer1_tx_t tx;
+	layer1_rx_t rx;
+
+	// ** Initialize **
+
+	RESULT_CHECK(layer1_tx_init(&tx));
+	RESULT_CHECK(layer1_rx_init(&rx, cb_rx));
+
+
+
+	// ** Generate packets **
+
+	RESULT_CHECK(layer1_tx_reset(&tx));
+
+	uint8_t packetbuf1[] = "Hello World! 1234567890";
+	size_t l = sizeof(packetbuf1);
+
+	fprintf(stderr, "Transmitting packet with %zd bytes.\n", l);
+
+	RESULT_CHECK(layer1_tx_add_packet_to_burst(&tx, packetbuf1, l));
+
+	uint8_t packetbuf2[] = "This is just a test message. Just writing some stuff here to create a longer packet.";
+	l = sizeof(packetbuf2);
+
+	fprintf(stderr, "Transmitting packet with %zd bytes.\n", l);
+
+	RESULT_CHECK(layer1_tx_add_packet_to_burst(&tx, packetbuf2, l));
+
+	RESULT_CHECK(layer1_tx_finalize_burst(&tx));
+
+	size_t burst_len = layer1_tx_get_sample_count(&tx);
+	const float complex *whole_burst = layer1_tx_get_sample_data(&tx);
+
+	dump_array_cf(whole_burst, burst_len, 10e-6f, "/tmp/tx.cpx");
+
+	// ** Simulate channel effects **
+	channel_cccf ch = channel_cccf_create();
+	//channel_cccf_add_awgn(ch, -30, 15);
+	channel_cccf_add_carrier_offset(ch, 0.01f, 1.23f);
+
+	float complex whole_burst_ch[burst_len];
+	channel_cccf_execute_block(ch, (float complex*)whole_burst, burst_len, whole_burst_ch);
+
+	dump_array_cf(whole_burst_ch, burst_len, 10e-6f, "/tmp/rx.cpx");
+
+
+	// ** Receive signal **
+
+	RESULT_CHECK(layer1_rx_process(&rx, whole_burst_ch, burst_len));
+
+	// ** Cleanup **
+
+	layer1_tx_shutdown(&tx);
+	layer1_rx_shutdown(&rx);
+
+	fprintf(stderr, "Done.\n");
+}