diff --git a/impl/src/layer1/rx.c b/impl/src/layer1/rx.c
index 1a4e30a..43e09db 100644
--- a/impl/src/layer1/rx.c
+++ b/impl/src/layer1/rx.c
@@ -84,15 +84,16 @@ static bool acquire_preamble(layer1_rx_t *rx, const float complex sample, bool d
 
 	if(abs_corr_out > 0.5f * preamble_get_symbol_count()) {
 		// Preamble found!
-		DEBUG_LOG("Preamble found: %.3f > %.3f\n", abs_corr_out, 0.5f * preamble_get_symbol_count());
+		DEBUG_LOG("@%zu: Preamble found: %.3f > %.3f\n", rx->sample_index,
+				abs_corr_out, 0.5f * preamble_get_symbol_count());
 
 		rx->packet_debug_info.preamble_correlation_peak = abs_corr_out;
 
 		float phase_offset;
 		float mean_frequency_error = correlator_get_mean_frequency_deviation(&rx->preamble_correlator, FREQ_EST_L, &phase_offset);
 
-		DEBUG_LOG("Phase offset:                 %.6f rad\n", phase_offset);
-		DEBUG_LOG("Preamble frequency deviation: %.6f rad/symbol\n", mean_frequency_error);
+		DEBUG_LOG("@%zu: Phase offset:                 %.6f rad\n", rx->sample_index, phase_offset);
+		DEBUG_LOG("@%zu: Preamble frequency deviation: %.6f rad/symbol\n", rx->sample_index, mean_frequency_error);
 
 		// Set the fine carrier correction NCO to the values estimated from the preamble
 		nco_crcf_set_frequency(rx->carrier_fine_nco, mean_frequency_error);
@@ -100,7 +101,8 @@ static bool acquire_preamble(layer1_rx_t *rx, const float complex sample, bool d
 
 		float fcoarse = nco_crcf_get_frequency(rx->carrier_coarse_nco);
 		float ffine = nco_crcf_get_frequency(rx->carrier_fine_nco);
-		DEBUG_LOG("New estimated carrier frequency: %.6f + %.6f/4 = %.6f rad/sample\n", fcoarse, ffine, fcoarse+ffine/4);
+		DEBUG_LOG("@%zu: New estimated carrier frequency: %.6f + %.6f/4 = %.6f rad/sample\n",
+				rx->sample_index, fcoarse, ffine, fcoarse+ffine/4);
 
 		// store debug info
 		rx->packet_debug_info.carrier_tracked_freq = fcoarse * 4 * SYMBOL_RATE / (2.0f * (float)M_PI);
@@ -119,7 +121,8 @@ static bool acquire_preamble(layer1_rx_t *rx, const float complex sample, bool d
 		return true; // preamble found!
 	} else if(do_coarse_freq_est) {
 		// preamble not found.
-		//DEBUG_LOG("Preamble not found: %.3f < %.3f\n", cabsf(corr_out), 0.5f * preamble_get_symbol_count());
+		//DEBUG_LOG("@%zu: Preamble not found: %.3f < %.3f\n",
+		//          rx->sample_index, cabsf(corr_out), 0.5f * preamble_get_symbol_count());
 
 		// Run the frequency estimator for every incoming sample overy the last
 		// FREQ_EST_L samples. This is an implementation that works with unknown
@@ -153,8 +156,9 @@ static bool acquire_preamble(layer1_rx_t *rx, const float complex sample, bool d
 
 				//freq_est_history_write_idx = 0;
 
-				DEBUG_LOG("Freq. est (x%d): %0.6f - Adj (x1): %.6f - carrier frequency (x1): %.6f\n",
-						RRC_SPS, freq_est, freq_adjustment, nco_crcf_get_frequency(rx->carrier_coarse_nco));
+				DEBUG_LOG("@%zu: Freq. est (x%d): %0.6f - Adj (x1): %.6f - carrier frequency (x1): %.6f\n",
+						rx->sample_index, RRC_SPS, freq_est, freq_adjustment,
+						nco_crcf_get_frequency(rx->carrier_coarse_nco));
 
 				freq_est_holdoff_samples = preamble_get_symbol_count() * 2;
 			}
@@ -257,7 +261,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 	float complex filtered_samples[sample_count];
 	firfilt_crcf_execute_block(rx->channel_filter, (float complex *)samples, sample_count, filtered_samples);
 
-	DEBUG_LOG("\nagc: %f\n", agc_crcf_get_gain(rx->agc));
+	//DEBUG_LOG("@%zu: agc: %f\n", rx->sample_index, agc_crcf_get_gain(rx->agc));
 
 	for(unsigned int i = 0; i < sample_count; i++) {
 		rx->sample_index++;
@@ -340,7 +344,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 						modem_demodulate(rx->hdr_demod, mixed_sample, &sym_demod);
 
 						float phase_error = modem_get_demodulator_phase_error(rx->hdr_demod);
-						DEBUG_LOG("Sym: %d; Phase error: %f %s\n", sym_demod, phase_error,
+						DEBUG_LOG("@%zu: Sym: %d; Phase error: %f %s\n", rx->sample_index, sym_demod, phase_error,
 								(fabs(phase_error) > 0.3) ? "!!!" : "");
 
 
@@ -365,7 +369,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 									header_enc, 8, sizeof(header_enc), &nsyms));
 
 						if(fec_decode(rx->hdr_fec, sizeof(header), header_enc, header) != LIQUID_OK) {
-							DEBUG_LOG("Header decoding failed!\n");
+							DEBUG_LOG("@%zu: Header decoding failed!\n", rx->sample_index);
 							rx->state = RX_STATE_ACQUISITION;
 							rx->callback(RX_EVT_HEADER_ERROR, rx, NULL, 0);
 							break;
@@ -374,8 +378,8 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 						// CRC check
 						if(crc_check_key(LIQUID_CRC_8, header, HEADER_SIZE_BYTES) != LIQUID_OK) {
 							uint8_t expected_crc = crc_generate_key(LIQUID_CRC_8, header, 4);
-							DEBUG_LOG("Header CRC check failed! Expected: 0x%02x, received: 0x%02x\n",
-									expected_crc, header[4]);
+							DEBUG_LOG("@%zu: Header CRC check failed! Expected: 0x%02x, received: 0x%02x\n",
+									rx->sample_index, expected_crc, header[4]);
 							rx->state = RX_STATE_ACQUISITION;
 							rx->callback(RX_EVT_HEADER_ERROR, rx, NULL, 0);
 							break;
@@ -387,7 +391,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 
 						// check the received information
 						if(!MODCOD_IS_VALID(rx->modcod)) {
-							DEBUG_LOG("Decoded MODCOD %d is invalid!\n", rx->modcod);
+							DEBUG_LOG("@%zu: Decoded MODCOD %d is invalid!\n", rx->sample_index, rx->modcod);
 							rx->state = RX_STATE_ACQUISITION;
 							rx->callback(RX_EVT_HEADER_ERROR, rx, NULL, 0);
 							break;
@@ -395,7 +399,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 
 						// check the payload length
 						if(rx->payload_len_bytes == 0) {
-							DEBUG_LOG("Packet length %u is not supported.\n", rx->payload_len_bytes);
+							DEBUG_LOG("@%zu: Packet length %u is not supported.\n", rx->sample_index, rx->payload_len_bytes);
 							rx->state = RX_STATE_ACQUISITION;
 							rx->callback(RX_EVT_HEADER_ERROR, rx, NULL, 0);
 							break;
@@ -408,7 +412,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 						rx->payload_len_symbols = (rx->payload_len_enc_bytes * 8 + payload_bps - 1) / payload_bps;
 
 						if(rx->payload_len_symbols > SYMBOL_BUFFER_SIZE) {
-							DEBUG_LOG("Symbol count %u is too lange for buffer. Ignoring packet.\n", rx->payload_len_symbols);
+							DEBUG_LOG("@%zu: Symbol count %u is too lange for buffer. Ignoring packet.\n", rx->sample_index, rx->payload_len_symbols);
 							rx->state = RX_STATE_ACQUISITION;
 							rx->callback(RX_EVT_HEADER_ERROR, rx, NULL, 0);
 							break;
@@ -416,7 +420,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 
 						assert(rx->payload_len_symbols < sizeof(symbols_int)/sizeof(symbols_int[0]));
 
-						DEBUG_LOG("=== DECODED HEADER ===\n");
+						DEBUG_LOG("=== DECODED HEADER @%zu ===\n", rx->sample_index);
 						DEBUG_LOG("Payload length: %u symbols, %u bytes encoded, %u bytes decoded\n", rx->payload_len_symbols, rx->payload_len_enc_bytes, rx->payload_len_bytes);
 						DEBUG_LOG("CRC16: 0x%04x\n", rx->payload_crc);
 						DEBUG_LOG("======================\n");
@@ -440,7 +444,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 						modem_demodulate(rx->payload_demod, mixed_sample, &sym_demod);
 
 						float phase_error = modem_get_demodulator_phase_error(rx->payload_demod);
-						//DEBUG_LOG("Sym: %d; Phase error: %f\n", sym_demod, phase_error);
+						//DEBUG_LOG("@%zu: Sym: %d; Phase error: %f\n", rx->sample_index, sym_demod, phase_error);
 
 						update_nco_pll(rx->carrier_fine_nco, phase_error, PLL_BW_DATA);
 
@@ -487,6 +491,7 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 		}
 
 		if(rx->state != last_state) {
+			DEBUG_LOG("@%zu: RX state changed: %d -> %d\n", rx->sample_index, last_state, rx->state);
 			if(rx->state == RX_STATE_ACQUISITION) {
 				// ensure the AGC is in acquisition mode again when
 				// RX_STATE_ACQUISITION is entered.