- improvement: error calulation only on bit change. Need to adjust loop parameter

git-svn-id: http://moon:8086/svn/matlab/trunk@104 801c6759-fa7c-4059-a304-17956f83a07c

garage_ip.m

@@ -22,13 +22,29 @@
 ## Author: Jens Ahrensfeld <ahrensfeld@w2ess001vm>
 ## Created: 2018-12-06
 
-function [bits, x] = garage_ip (numSamplesPerSym)
+function [bits] = garage_ip (varargin)
 
-k_n = 0.01;	% NOise
+params = struct ('x', [], 'baudrate', 9600, 'numSamplesPerSym', 16, 'with_filter', 0, 'k_noise', 0.00);
+units = struct ('x', '', 'baudrate', 'baud', 'numSamplesPerSym', 'sps', 'with_filter', '', 'k_noise', '');
+
+% Parse parameters
+names = fieldnames(params);
+for k=1:nargin-1,
+	for n=1:length(names),
+		if strcmpi(varargin{k}, names{n})
+			params.(names{n}) = varargin{k+1};
+		end
+	end
+end
+	
+print_parameters(params, units)
+
+k_n = params.k_noise;		% NOise
 k_s = 1.0;		% Sym
 
+numSamplesPerSym = params.numSamplesPerSym;
 baud_init = 2900;
-fs = baud_init * numSamplesPerSym
+fs = baud_init * numSamplesPerSym;
 
 numSyms = 100;
 numBursts = 3;
@@ -41,24 +57,29 @@ bit = 0;
 syms_m = manchester(syms);
 
 % Upconvert
-x = zeros(1, 2*numSymsPauseBetweenBurst*numSamplesPerSym);
-
-for k=1:numBursts
-	for n=1:2*numSyms,
-		for m=1:numSamplesPerSym,
-			x = [x syms_m(n)];
+if isempty(params.x)
+	x = zeros(1, 2*numSymsPauseBetweenBurst*numSamplesPerSym);
+	for k=1:numBursts
+		for n=1:2*numSyms,
+			for m=1:numSamplesPerSym,
+				x = [x syms_m(n)];
+			end
 		end
+		x = [x zeros(1, numSymsPauseBetweenBurst*numSamplesPerSym)];
 	end
-	x = [x zeros(1, numSymsPauseBetweenBurst*numSamplesPerSym)];
-end
-x = [x zeros(1, 20*numSymsPauseBetweenBurst*numSamplesPerSym)];
-
-% Channel
-[b,a] = butter(2, numSamplesPerSym/4*baud_init/fs);
-y = resample (x, 3200, baud_init);
-%y = x;
-y = k_s*filter(b, a, y) + k_n*randn(1, length(y));
+	x = [x zeros(1, 20*numSymsPauseBetweenBurst*numSamplesPerSym)];
 
+	% Channel
+	y = resample (x, 3200, baud_init);
+	%y = x;
+	if params.with_filter
+		[b,a] = butter(2, numSamplesPerSym/4*baud_init/fs);
+		y = k_s*filter(b, a, y) + k_n*randn(1, length(y));
+	end
+else
+  x = params.x;
+  y = x;
+end  
 N = length(y);
 
 baud = baud_init;
@@ -74,11 +95,12 @@ bits = [];
 v_min = 0;					% Threshold max
 v_max = 0;					% Threshold min
 hyst_thr = 0.5;				% Threshold hysteresis
-rho_thr = 1e-4;				% Threshold forgetting factor
+rho_thr = 1e-5;				% Threshold forgetting factor
 alpha_thr = 0.1;			% Min/Max update factor
-alpha_lead = 0.02;			% Symbol syncronizer loop filter lead 
-alpha_lag = 0.000008;		% Symbol syncronizer loop filter lag 
-lag_accu = 1;				% Symbol syncronizer loop filter
+alpha_lead = 0.1;			% Symbol syncronizer loop filter lead 
+alpha_lag = 0.0001;			% Symbol syncronizer loop filter lag 
+lag_accu = 0;				% Symbol syncronizer loop filter
+k_leak = 0;					% Lag forgetting factor
 loopThreshold = 0.1;		% Processing threshold
 ns = 1;						% Start sample source
 n = 1;						% Start sample sink
@@ -114,12 +136,11 @@ while ns < N
 	end
 	
 	% Calc error
-	if (bitChg)
+	err = 0;
+	if (bitChg && (v_thr >=loopThreshold))
 		err = -(count - fix(numSamplesPerSym/2));
 	end
-	if v_thr < loopThreshold
-		err = 0;
-	end
+
 	% Sample bit at baud rate = fs/numSamplesPerSym
 	if count == 0
 		smp = [smp ys];
@@ -133,15 +154,15 @@ while ns < N
 	end
 	vcorr = alpha_lead*err + lag_accu;
 	lag_accu = lag_accu + alpha_lag*err;
-	lag_accu = lag_accu*(1-1e-8);
-	baud = vcorr*fs/numSamplesPerSym;
+	lag_accu = lag_accu * (1-k_leak);
+	baud = (1+vcorr)*fs/numSamplesPerSym;
 	_err(n) = err;
 	_baud(n) = baud;
 	_cnt(n) = vcorr;
 	_v_tr(n) = v_thr;
 	_ys(n) = ys;
 	n = n + 1;
-	ns = ns + vcorr;
+	ns = ns + (1+vcorr);
 end
 bits = bits';
 
@@ -149,7 +170,7 @@ n = 1:length(_ys);
 
 % Plot
 subplot(3, 1, 1)
-plot(n, _ys, n, _v_tr, 'y', smp_n, smp, 'ro'); grid;
+plot(n, _ys, '-o', n, _v_tr, 'y', smp_n, smp, 'ro'); grid;
 subplot(3, 1, 2)
 plot(n, _err); grid;
 subplot(3, 1, 3)