baseline rate Rs BPSK AWGN simulation, about to add HF

git-svn-id: https://svn.code.sf.net/p/freetel/code@3082 01035d8c-6547-0410-b346-abe4f91aad63

diff --git a/codec2-dev/octave/bpsk_hf.m b/codec2-dev/octave/bpsk_hf.m
new file mode 100644 (file)
index 0000000..a117c1a
--- /dev/null
+++ b/codec2-dev/octave/bpsk_hf.m
@@ -0,0 +1,78 @@
+% bpsk_hf.m
+% David Rowe Mar 2017
+%
+% Rate Rs BPSk simulation to explore phase over multiple carriers in HF channel
+
+1;
+
+function sim_out = run_sim(sim_in)
+  Rs = 50;
+
+  Nbits = sim_in.Nbits;
+  EbNodB = sim_in.EbNodB;
+  verbose = sim_in.verbose;
+
+  for nn=1:length(EbNodB)
+    EbNo = 10 .^ (EbNodB(nn)/10);
+    variance = 1/(EbNo/2);
+    noise = sqrt(variance)*(0.5*randn(1,Nbits) + j*0.5*randn(1,Nbits));
+
+    tx = zeros(1,Nbits);
+    rx = zeros(1,Nbits);
+    tx_bits = rand(1,Nbits) > 0.5;
+    tx = 1 - 2*tx_bits;
+    rx = tx + noise;
+
+    rx_bits = real(rx) < 0;
+    errors = xor(tx_bits, rx_bits);
+    Nerrs = sum(errors);                                         
+    printf("EbNodB: %3.2f BER: %4.3f Nbits: %d Nerrs: %d\n", EbNodB(nn), Nerrs/Nbits, Nbits, Nerrs);
+
+    if verbose
+      figure(1); clf; 
+      plot(rx,'+');
+      axis([-2 2 -2 2]);
+    end
+
+    sim_out.ber(nn) = Nerrs/Nbits;
+  end
+endfunction
+
+
+function run_curves
+  sim_in.verbose = 0;
+  sim_in.Nbits = 10000;
+  sim_in.EbNodB = 0:6;
+
+  bpsk_out = run_sim(sim_in);
+
+  figure(3); clf;
+  semilogy(sim_in.EbNodB, bpsk_out.ber,'b+-;BPSK;');
+  xlabel('Eb/No (dB)');
+  ylabel('BER');
+  grid;
+  legend('boxoff');
+  title('Coherent BPSK');
+
+end
+
+
+function run_single
+  sim_in.Nbits = 1000;
+  sim_in.EbNodB = 4;
+  sim_in.verbose = 1;
+
+  run_sim(sim_in);
+end
+
+
+format;
+more off;
+rand('seed',1);
+randn('seed',1);
+
+run_single
+%run_curves
+
+
+