diff --git a/ofdm/ofdm_rx.m b/ofdm/ofdm_rx.m
index 7231180..7c9f21f 100644
--- a/ofdm/ofdm_rx.m
+++ b/ofdm/ofdm_rx.m
@@ -1,8 +1,9 @@
-function [sym_out, H, W] = ofdm_rx(filename, foff, SNR, with_cir)
+function [sym_out, H, W] = ofdm_rx(filename, foff, SNR, with_cir, show_H)
 %
-% Example: ofdm_rx('drm-15435-if.wav', -174.65, 400, 0)
-% Example: ofdm_rx('xv.wav', 0, 400, 0)
-%       or ofdm_rx('yv.wav', 0, 400, 0)
+% [sym_out, H, W] = ofdm_rx(filename, foff, SNR, with_cir, show_H)
+% Example: ofdm_rx('drm-15435-if.wav', -174.65, 400, 0, 1)
+% Example: ofdm_rx('xv.wav', 0, 400, 0, 1)
+%       or ofdm_rx('yv.wav', 0, 400, 0, 1)
 
 close all;
 
@@ -263,7 +264,7 @@ for k=start:length(Z_)
 		ZZ = Z_(carrier_indexes, k-symbols_to_delay).';
     	sym_eq = ZZ ./ H;
 		sym_out(:, kk) = sym_eq;
-        if 0
+        if show_H
 			H_raw(1:2:N) = H_raw(2:2:N);
 			subplot(3, 1, 1)
 			plot(carriers, abs(H_raw(carrier_indexes)), 'b-', carriers, abs(H), 'r-'); grid; title('abs(H)'); axis([ofdm_spec_occ.kmin ofdm_spec_occ.kmax 0 15+0*max(abs(H))]); title(str);
@@ -285,10 +286,10 @@ for k=start:length(Z_)
             if (~isempty(fac_c))
 				fac_i = fac_c - ofdm_spec_occ.kmin + 1;
 				hold on;
-		        plot(sym_eq(fac_i), '.', 'MarkerSize', 4);
+		        plot(sym_eq(fac_i), '+', 'MarkerSize', 4);
 			    pause(0.01);
+				grid; title('FAC'); axis([-1 1 -1 1]);
 				hold off;
-				grid; title('FAC'); axis([-1.5 1.5 -1.5 1.5]);
 			end
         end
     end
diff --git a/ofdm/ofdm_tx.m b/ofdm/ofdm_tx.m
index 175b026..5685fcb 100644
--- a/ofdm/ofdm_tx.m
+++ b/ofdm/ofdm_tx.m
@@ -1,7 +1,7 @@
-function [yv xv] = ofdm_tx(mode, bandwidth, N_frames, withData, plot_speed)
+function [yv xv] = ofdm_tx(mode, bandwidth, N_frames, withData, M_QAM, plot_speed)
 %
-% function [yv xv] = ofdm_tx(mode, bandwidth, N_frames, withData, plot_speed)
-% Example : ofdm_tx('B', '10k', 500, 1, 0);
+% function [yv xv] = ofdm_tx(mode, bandwidth, N_frames, withData, M_QAM, plot_speed)
+% Example : ofdm_tx('B', '10k', 500, 1, 64, 0);
 %
 
 close all;
@@ -14,7 +14,6 @@ WITH_GAIN_REF = 1;
 WITH_DATA = withData;
 DELAY = 100;
 
-M_QAM = 64;
 RCWIN_ROLLOFF = 0.125;
 
 % Params