- refactored

common/fft/pfftcnv3.m

@@ -0,0 +1,86 @@
+% pfftcnv2(x,b)
+function y = pfftcnv2(x,h,P,S,L)
+
+N = length(h);
+Lx = length(x);
+C = 2^ceil(log(L+S*L-1)/log(2));
+Np = S*L;
+K = Lx/L;
+
+y = zeros(1,Lx);
+hp = zeros(P,C);
+Hp = zeros(P,C);
+xk = zeros(1,C);
+Xk = zeros(1,C);
+Xkps = zeros(S*P,C);
+yk = zeros(1,C);
+Y  = zeros(1,C);
+xzp = zeros(1,Lx+C-L);
+pidTbl = [2:P*S];
+pidTbl(P*S) = 1;
+pStbl = [0:P*S-1];
+pStbl(1) = 10;
+
+pid = 1;
+
+% h(k) => hp(k)
+for p=1:P,
+  SLp = (p-1)*Np;
+  hp(p,1:Np) = h(SLp+1:SLp+Np);
+end;
+
+% hp(k) => Hp(k)
+for p=1:P,
+  Hp(p,1:C) = fft(hp(p,1:C),C);
+end;
+
+xzp(C-L+1:Lx+C-L) = x;
+
+tic;
+
+for k=1:K,
+  
+  kL = (k-1)*L;
+  xk(1:C) = xzp(kL+1:kL+C);
+  
+  Xkps(pid,1:C) = fft(xk,C);
+    
+  pS = pid;
+  Y = Hp(1,1:C).*Xkps(pid,1:C);
+  for p=2:P,
+    for i = 1:S
+      pS = pStbl(pS);
+    end;
+    Y   = Y + Hp(p,1:C).*Xkps(pS,1:C);
+  end;
+
+  yk = ifft(Y,C);
+ 
+  y(kL+1:kL+L) = yk(C-L+1:C);
+ 
+  pid = pidTbl(pid);
+
+end;
+toc;
+
+SUBPLOT(2,1,1),
+  plot(1:N,h);
+  n = [1:N];
+  XT = [Np*n];
+  set(gca,'XTick',XT);
+  grid;
+  PlotTitle = sprintf('Filterkoeffizienten h(n), N=%d, P=%d, S=%d, NP=%d',N,P,S,Np);
+  title(PlotTitle);
+  xlabel('n');
+  ylabel('h');
+
+SUBPLOT(2,1,2), 
+  plot(1:K*L,real(y(1:K*L)));
+  n = [1:N];
+  XT = [L*n];
+  set(gca,'XTick',XT);
+  grid;
+  PlotTitle = sprintf('Filterausgang y(n), K=%d, L=%d, C=%d',K,L,C);
+  title(PlotTitle);
+  xlabel('n');
+  ylabel('y');