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- added signal detection

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git-svn-id: http://moon:8086/svn/matlab/trunk@110 801c6759-fa7c-4059-a304-17956f83a07c
This commit is contained in:
jens
2019-01-07 10:49:50 +00:00
parent 55539f2ab0
commit 0d51e311a6
1 changed files with 33 additions and 18 deletions
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garage_ip.m
+33 -18
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@@ -95,17 +95,23 @@ 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-3; % Threshold forgetting factor
alpha_thr = 0.1; % Min/Max update factor
k_leadLag = params.loopFilterGain; % Overall loopfilter gain (scales k_lead and k_lag)
k_lead = 0.1; % Symbol syncronizer loop filter lead
k_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
loopThreshold = 0.05; % Processing threshold
ns = 1; % Start sample source
n = 1; % Start sample sink
err = 0; % Error
alpha_sig = 0.5/numSamplesPerSym;
alpha_sig_m = alpha_sig/5;
v_sig = 0;
v_sig_m = 0.5;
while ns < N
% Get next interpolated sample
is = fix(ns);
@@ -122,32 +128,41 @@ while ns < N
v_min = v_min + rho_thr*(v_thr - v_min);
v_max = v_max + rho_thr*(v_thr - v_max);
% Signal detection
y_nodc = ys-v_thr;
v_sig = (1-alpha_sig)*v_sig + alpha_sig*y_nodc*y_nodc;
v_sig_m = (1-alpha_sig_m)*v_sig_m + alpha_sig_m*ys;
isSignal = v_sig >= loopThreshold;
% Detect bit change
bitChg = 0;
if (bit == 1)
if ys < (hyst_thr*v_thr)
bit = 0;
bitChg = 1;
end
else
if ys > (hyst_thr*v_thr)
bit = 1;
bitChg = 1;
if isSignal
if (bit == 1)
if ys < (hyst_thr*v_thr)
bit = 0;
bitChg = 1;
end
else
if ys > (hyst_thr*v_thr)
bit = 1;
bitChg = 1;
end
end
end
isSignal = (v_thr >=loopThreshold);
% Calc error
err = 0;
if (bitChg && isSignal)
if (bitChg)
err = -(count - fix(numSamplesPerSym/2));
end
% Sample bit at baud rate = fs/numSamplesPerSym
if count == 0 && isSignal
smp = [smp ys];
smp_n = [smp_n n];
bits = [bits bit];
if isSignal
smp = [smp ys];
smp_n = [smp_n n];
end
end;
if count > 0
count = count - 1;
@@ -161,7 +176,7 @@ while ns < N
_err(n) = err;
_baud(n) = baud;
_cnt(n) = vcorr;
_v_tr(n) = v_thr;
_v_tr(n) = v_sig;
_ys(n) = ys;
n = n + 1;
ns = ns + (1+vcorr);
@@ -172,7 +187,7 @@ n = 1:length(_ys);
% Plot
subplot(3, 1, 1)
plot(n, _ys, '-o', n, _v_tr, 'y', smp_n, smp, 'ro'); grid;
plot(n, _ys, '-o', n, _v_tr, 'm', smp_n, smp, 'ro'); grid;
subplot(3, 1, 2)
plot(n, _err); grid;
subplot(3, 1, 3)