diff --git a/impl/src/layer1/rx.c b/impl/src/layer1/rx.c
index 852dd26..d0fae51 100644
--- a/impl/src/layer1/rx.c
+++ b/impl/src/layer1/rx.c
@@ -260,6 +260,8 @@ result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t
 	DEBUG_LOG("\nagc: %f\n", agc_crcf_get_gain(rx->agc));
 
 	for(unsigned int i = 0; i < sample_count; i++) {
+		rx->sample_index++;
+
 		rx_state_t last_state = rx->state;
 
 		// Apply the AGC.
@@ -560,6 +562,8 @@ result_t layer1_rx_init(layer1_rx_t *rx, rx_callback_t callback)
 	var_array_cf_init(&rx->packet_debug_info.header_symbols);
 	var_array_cf_init(&rx->packet_debug_info.data_symbols);
 
+	rx->sample_index = 0;
+
 	reset_packet_debug_info(rx);
 
 	return OK;
diff --git a/impl/src/layer1/rx.h b/impl/src/layer1/rx.h
index 7ddac52..6564592 100644
--- a/impl/src/layer1/rx.h
+++ b/impl/src/layer1/rx.h
@@ -73,6 +73,9 @@ typedef struct layer1_rx_s
 	uint16_t payload_len_enc_bytes;
 	modcod_t modcod;
 
+	// sample counter (for debug messages)
+	size_t sample_index;
+
 	// packet debugging information
 	rx_packet_dbg_t packet_debug_info;
 } layer1_rx_t;