1 files changed, 0 insertions, 78 deletions
diff --git a/octave/hf_sim.m b/octave/hf_sim.m
deleted file mode 100644
index c9105c0..0000000
--- a/octave/hf_sim.m
+++ /dev/null
@@ -1,78 +0,0 @@
-% hf_sim.m
-% David Rowe March 2014
-%
-% Two path CCIR poor HF channel simulation, with apaologies to PathSim
-
-% Init HF channel model from stored sample files of spreading signal ----------------------------------
-
-global spread;
-global spread_2ms;
-global hf_gain;
-
-% convert "spreading" samples from 1kHz carrier at Fs to complex
-% baseband, generated by passing a 1kHz sine wave through PathSim with
-% the ccir-poor model, enabling one path at a time.  Because I'm too
-% lazy to generate my own spreading signals
-    
-Fc = 1000; Fs=8000;
-fspread = fopen("../raw/sine1k_2Hz_spread.raw","rb");
-spread1k = fread(fspread, "int16")/10000;
-fclose(fspread);
-fspread = fopen("../raw/sine1k_2ms_delay_2Hz_spread.raw","rb");
-spread1k_2ms = fread(fspread, "int16")/10000;
-fclose(fspread);
-
-% down convert to complex baseband
-
-spreadbb = spread1k.*exp(-j*(2*pi*Fc/Fs)*(1:length(spread1k))');
-spreadbb_2ms = spread1k_2ms.*exp(-j*(2*pi*Fc/Fs)*(1:length(spread1k_2ms))');
-
-% remove -2000 Hz image
-
-b = fir1(50, 5/Fs);
-spread = filter(b,1,spreadbb);
-spread_2ms = filter(b,1,spreadbb_2ms);
-
-% discard first 1000 samples as these were near 0, probably as
-% PathSim states were ramping up
-
-spread     = spread(1000:length(spread));
-spread_2ms = spread_2ms(1000:length(spread_2ms));
-
-hf_gain = 1.0/sqrt(var(spread)+var(spread_2ms));
-
-% This function simulates the HF channel at 8kHz for real signals.  A
-% good use case is passing a vector of speech samples through it to
-% simulate SSB over HF.  There's a really good reason for the 300 -
-% 3000 Hz filter that escapes me right now :-)
-
-function [sim_out snr3kHz_measured ] = hf_sim_real(sim_in, snr3kHz)
-
-    % 300 - 3000 Hz filter
-
-    b = fir1(100,[300/4000, 3000/4000], 'pass');
-    
-    % det power of unit variance noise passed through this filter
-    
-    filter_var = var(filter(b,1,randn(1000,1)));
-    
-    % Start simulation
-
-    s = hilbert(filter(b,1,sim_in));
-    n1 = length(s); n2 = length(spread);
-    n = min(n1,n2);
-    path1 = s(1:n) .* spread(1:n);
-    path2 = s(1:n) .* spread_2ms(1:n);
-    delay = floor(0.002*Fs);
-
-    combined = path1(delay+1:n) + path2(1:n-delay);
-
-    snr = 10 .^ (snr3kHz/10);
-    variance = (combined'*combined)/(snr*n);
-    noise = sqrt(variance*0.5/filter_var)*(randn(n-delay,1) + j*randn(n-delay,1));
-    filtered_noise = filter(b,1,noise);
- 
-    sim_out = real(combined+filtered_noise);
-    snr3kHz_measured = 10*log10(var(real(combined))/var(real(filtered_noise)));
-endfunction
-