diff --git a/src/freedv_700.c b/src/freedv_700.c
index 40aa2c08..72e05632 100644
--- a/src/freedv_700.c
+++ b/src/freedv_700.c
@@ -198,6 +198,7 @@ void freedv_ofdm_data_open(struct freedv *f, struct freedv_advanced *adv) {
   if (f->mode == FREEDV_MODE_DATAC4) strcpy(mode, "datac4");
   if (f->mode == FREEDV_MODE_DATAC13) strcpy(mode, "datac13");
   if (f->mode == FREEDV_MODE_DATAC14) strcpy(mode, "datac14");
+  if (f->mode == FREEDV_MODE_QAM16C2) strcpy(mode, "qam16c2");
   if (f->mode == FREEDV_MODE_DATA_CUSTOM) {
     assert(adv != NULL);
     assert(adv->config != NULL);
@@ -506,8 +507,6 @@ int freedv_comp_short_rx_ofdm(struct freedv *f, void *demod_in_8kHz,
       symbols_to_llrs(llr, payload_syms_de, payload_amps_de, EsNo,
                       ofdm->mean_amp, ofdm->bps, Npayloadsymsperpacket);
       ldpc_decode_frame(ldpc, &parityCheckCount, &iter, decoded_codeword, llr);
-      // iter = run_ldpc_decoder(ldpc, decoded_codeword, llr,
-      // &parityCheckCount);
       memcpy(f->rx_payload_bits, decoded_codeword, Ndatabitsperpacket);
 
       if (strlen(ofdm->data_mode)) {
diff --git a/src/freedv_api.c b/src/freedv_api.c
index d04dd7c8..cb9e7064 100644
--- a/src/freedv_api.c
+++ b/src/freedv_api.c
@@ -131,7 +131,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode) ||
-       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode)) == false)
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode) ||
+       FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, mode)) == false)
     return NULL;
 
   /* set everything to zero just in case */
@@ -165,6 +166,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
     freedv_ofdm_data_open(f, NULL);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, mode))
     freedv_ofdm_data_open(f, adv);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, mode))
+    freedv_ofdm_data_open(f, NULL);
 
   varicode_decode_init(&f->varicode_dec_states, 1);
 
@@ -248,6 +251,7 @@ void freedv_close(struct freedv *freedv) {
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, freedv->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, freedv->mode)) {
     FREE(freedv->rx_syms);
     FREE(freedv->rx_amps);
@@ -281,6 +285,7 @@ static int is_ofdm_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode);
 }
 
@@ -291,6 +296,7 @@ static int is_ofdm_data_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode);
 }
 
@@ -483,6 +489,7 @@ void freedv_rawdatacomptx(struct freedv *f, COMP mod_out[],
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode))
     freedv_comptx_ofdm(f, mod_out);
 
@@ -1084,6 +1091,7 @@ int freedv_rawdatacomprx(struct freedv *f, unsigned char *packed_payload_bits,
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_QAM16C2, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATA_CUSTOM, f->mode))
     rx_status = freedv_comp_short_rx_ofdm(f, (void *)demod_in, 0, 1.0f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_FSK_LDPC, f->mode)) {
diff --git a/src/freedv_api.h b/src/freedv_api.h
index 9f72c8f9..4acf40ca 100644
--- a/src/freedv_api.h
+++ b/src/freedv_api.h
@@ -63,6 +63,7 @@ extern "C" {
 #define FREEDV_MODE_DATAC13 19
 #define FREEDV_MODE_DATAC14 20
 #define FREEDV_MODE_DATA_CUSTOM 21
+#define FREEDV_MODE_QAM16C2 22
 
 // Sample rates used
 #define FREEDV_FS_8000 8000
@@ -148,6 +149,9 @@ extern "C" {
 #if !defined(FREEDV_MODE_DATA_CUSTOM_EN)
 #define FREEDV_MODE_DATA_CUSTOM_EN FREEDV_MODE_EN_DEFAULT
 #endif
+#if !defined(FREEDV_MODE_QAM16C2_EN)
+#define FREEDV_MODE_QAM16C2_EN FREEDV_MODE_EN_DEFAULT
+#endif
 
 #define FDV_MODE_ACTIVE(mode_name, var) \
   ((mode_name##_EN) == 0 ? 0 : (var) == mode_name)
diff --git a/src/freedv_data_raw_rx.c b/src/freedv_data_raw_rx.c
index 435648d7..50fcb32f 100644
--- a/src/freedv_data_raw_rx.c
+++ b/src/freedv_data_raw_rx.c
@@ -217,6 +217,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC13;
   if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
     mode = FREEDV_MODE_DATAC14;
+  if (!strcmp(argv[dx], "QAM16C2") || !strcmp(argv[dx], "qam16c2"))
+    mode = FREEDV_MODE_QAM16C2;
   if (!strcmp(argv[dx], "CUSTOM") || !strcmp(argv[dx], "custom"))
     mode = FREEDV_MODE_DATA_CUSTOM;
   if (mode == -1) {
diff --git a/src/freedv_data_raw_tx.c b/src/freedv_data_raw_tx.c
index ce5da562..70fefe74 100644
--- a/src/freedv_data_raw_tx.c
+++ b/src/freedv_data_raw_tx.c
@@ -238,6 +238,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC13;
   if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
     mode = FREEDV_MODE_DATAC14;
+  if (!strcmp(argv[dx], "QAM16C2") || !strcmp(argv[dx], "qam16c2"))
+    mode = FREEDV_MODE_QAM16C2;
   if (!strcmp(argv[dx], "CUSTOM") || !strcmp(argv[dx], "custom"))
     mode = FREEDV_MODE_DATA_CUSTOM;
   if (mode == -1) {