Initial Commit

2018-02-08 21:28:33 -05:00
commit 678c1d3966
14352 changed files with 3176737 additions and 0 deletions
@@ -0,0 +1,21 @@
+subroutine degrade_snr(d2,npts,db,bw)
+
+! Degrade S/N by specified number of dB.
+
+  integer*2 d2(npts)
+  
+  p0=0.
+  do i=1,npts
+     x=d2(i)
+     p0=p0 + x*x
+  enddo
+  p0=p0/npts
+  if(bw.gt.0.0) p0=p0*6000.0/bw
+  s=sqrt(p0*(10.0**(0.1*db) - 1.0))
+  fac=sqrt(p0/(p0+s*s))
+  do i=1,npts
+     d2(i)=nint(fac*(d2(i) + s*gran()))
+  enddo
+
+  return
+end subroutine degrade_snr