From: Adrian Iain Lam <adrianiainlam@users.noreply.github.com>
Date: Fri, 26 Oct 2018 13:41:50 +0000 (+0100)
Subject: Fixed passband, should now be correct
X-Git-Url: https://adrianiainlam.tk/git/?p=4yp.git;a=commitdiff_plain;h=a4b0109e3e2d8034cf3ad776ed6c607b668b54ec

Fixed passband, should now be correct
---

diff --git a/passband.m b/passband.m
index 7abd749..5424ea4 100644
--- a/passband.m
+++ b/passband.m
@@ -34,8 +34,6 @@ function passband(rolloff, M, numSymbs)
   t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs)';
 
 
-
-
   EbN0_db = 0:0.2:10;
   EbN0 = 10 .^ (EbN0_db ./ 10);
 
@@ -58,15 +56,18 @@ function passband(rolloff, M, numSymbs)
 
   xBaseband = txFilter([modData; zeros(span, 1)]);
 
+
   %fc = 2.5e6; % Carrier freq (Hz)
   %carrier = sqrt(2) * exp(j * 2 * pi * fc * t);
 
   %xPassbandIdeal = normalizeEnergy...
   %                   (real(xBaseband .* carrier(1:length(xBaseband))), numSymbs, 1);
 
-  txLOFreq = [2.49e6, 2.5e6, 2.51e6];
+  %txLOFreq = [2.49e6, 2.5e6, 2.51e6];
   %%txLOEnergy = [0.05, 0.9, 0.05];
-  txLOEnergy = [0 1 0];
+  %txLOEnergy = [0 1 0];
+  txLOFreq = [1e8];
+  txLOEnergy = [1];
 
   carrier = zeros(length(t), 1);
   for i = 1 : length(txLOFreq)
@@ -75,27 +76,20 @@ function passband(rolloff, M, numSymbs)
   end
 
   xPassband = normalizeEnergy...
-                (real(xBaseband .* carrier(1:length(xBaseband))), numSymbs, 1);
-
-  sum(abs(xPassband) .^ 2) / numSymbs
-  input('pause')
-
+                (xBaseband .* carrier(1:length(xBaseband)), numSymbs, 1);
 
   for i = 1:plotlen
     snr = EbN0_db(i) + 10 * log10(log2(M)) - 10 * log10(sps); % why sps?
     noiseEnergy = 10 ^ (-snr / 10);
 
-
     yPassband = awgn(xPassband, snr, 'measured');
 
-
-    rBaseband = rxFilter([yPassband .* carrier(1:length(yPassband)); zeros(span * sps, 1)]);
+    rBaseband = rxFilter([yPassband .* conj(carrier(1:length(yPassband))); zeros(span * sps, 1)]);
     %% truncate filter transients
     rBaseband = rBaseband(span * sps / 2 + 1 : end);
     %% normalize energy
     rBaseband = normalizeEnergy(rBaseband, numSymbs, 1 + noiseEnergy);
 
-
     rSampled = rBaseband(sps*span/2+1:sps:(numSymbs + span/2) * sps);
 
     demodData = pskdemod(rSampled, M, 0, 'gray');