check_wimax_duc_s3sd_v1.m

基于matlab的Wimax数字中频DUC的仿真

%--------------------------------------------------------------------------
%Copyright (c) 2007 Xilinx, Inc.
%This code is confidential and proprietary of Xilinx, All Rights Reserved.
%--------------------------------------------------------------------------
%Filename: check_wimax_duc_s3sd_v1.m
%Purpose:  This program checks that the output of the wimax_duc_s3sd_v1
%          system generator design matches a bit-true behavioral model.
%--------------------------------------------------------------------------
BitTrue = 1;
DitherOn = 1;
Fs = 89.6;
Nfft = 1024;

%-------------------------------------------------------------------%
%Capture the design inputs and outputs after reset is released
%-------------------------------------------------------------------%
if find(Reset)
  tResetOff = max(find(Reset))+1;
else
  tResetOff = 1;
end
DataInAfterReset = Iin(tResetOff:end) + j*Qin(tResetOff:end);
SyncAfterReset = Sync(tResetOff:end);
DataOutAfterReset = Iout(tResetOff:end) + j*Qout(tResetOff:end);
ValidAfterReset = Valid(tResetOff:end);
x = DataInAfterReset(find(SyncAfterReset));

%-------------------------------------------------------------------%
%Model the interpolation filters
%-------------------------------------------------------------------%
load coefficients
if BitTrue  %Use simple round (matches hardware)
  y1 = floor(upfirdn(x,h1,2,1)*2^15 + 0.5 + 0.5*j)/2^15;
  y2 = floor(upfirdn(y1,h2,2,1)*2^15 + 0.5 + 0.5*j)/2^15;
  y3 = floor(upfirdn(y2,h3,2,1)*2^15 + 0.5 + 0.5*j)/2^15;
  y4 = floor(upfirdn(y3,h4,2,1)*2^15 + 0.5 + 0.5*j)/2^15;
else        %Use symmetric round (ideal)
  y1 = round(upfirdn(x,h1,2,1)*2^15)/2^15;
  y2 = round(upfirdn(y1,h2,2,1)*2^15)/2^15;
  y3 = round(upfirdn(y2,h3,2,1)*2^15)/2^15;
  y4 = round(upfirdn(y3,h4,2,1)*2^15)/2^15;
end

if BwSel(1)
  yfilt = y3;
  D = 10;
else
  yfilt = y4;
  D = 21;
end

%-------------------------------------------------------------------%
%Model the mixer
%-------------------------------------------------------------------%
if BitTrue
  %Make the frequency command a 32-bit unsigned integer
  FreqCmd = Freq(1);

  %Accumulate and wrap modulo 2^32.
  Accum = FreqCmd*[(1+D):1:length(yfilt)+D]';
  Accum = mod(Accum, 2^32);

  %Divide by 2^19 to obtain 13 bits of integer and 19 bits of fraction
  Accum = Accum/(2^19);

  %Add the dither sequence (modulo 2^13 to wrap on overflow)
  if DitherOn
    load dither_sequence
    Sum = Accum + floor(2^6*dither_sequence(2+D:length(Accum)+1+D))/2^7;
    Sum = mod(Sum, 2^13);
  else
    Sum = Accum;
  end

  %Truncate to 13 bits of integer and then shift to be all fractional
  Phase = floor(Sum)/2^13;

  %Compute the sine and cosine
  Delta = (0.5/8192);
  coswt = cos(2*pi*(Phase + Delta));
  sinwt = sin(2*pi*(Phase + Delta));

  %Quantize to 16 bits (signed)
  width = 16;
  maxvalue = 2^(width-1) - 1;
  xnorm = coswt/cos(2*pi*Delta);
  coswt = round(xnorm*maxvalue)/2^(width-1);
  xnorm = sinwt/cos(2*pi*Delta);
  sinwt = round(xnorm*maxvalue)/2^(width-1); 

  %Multiply the I and Q data by the cosine and sine
  yfilti = real(yfilt);
  yfiltq = imag(yfilt);
  ymixeri = floor((yfilti.*coswt - yfiltq.*sinwt)*2^15 + 0.5)/2^15;
  ymixerq = floor((yfiltq.*coswt + yfilti.*sinwt)*2^15 + 0.5)/2^15;
  ymixer = ymixeri + j*ymixerq;

else  %Multiply by a complex sinusoid
  f0 = (Freq(1)/2^32)*Fs;
  ymixer = yfilt.*exp(j*2*pi*(f0/Fs)*([1+D:1:length(yfilt)+D]' + 0.5/8192));
  ymixer = round(ymixer*2^15)/2^15;
end

%-------------------------------------------------------------------%
%Model the gain control
%-------------------------------------------------------------------%
y = round(2^15*Gain(1)*ymixer)/2^15;

%-------------------------------------------------------------------%
%Check that the implementation matches the bit-true model
%-------------------------------------------------------------------%
z = DataOutAfterReset(find(ValidAfterReset));
N = length(z((1+D):end-1));
err = y(1:N) - z((1+D):end-1);
if find(err)
  fprintf('Error: Mismatches found.\n');
  fprintf('Max Abs Error (LSBs): %d\n', max(max(abs([real(err), imag(err)])))*2^15);
  fprintf('Number of Mismatches: %d (out of %d)\n', length(find(err)), length(err));
else
  fprintf('Check Passed!\n');
end

figure
subplot(211)
plot(real(y(1:N)))
hold on; grid on; zoom on;
ylim([-1,1]);
plot(real(z((1+D):end-1)), 'm');
subplot(212)
plot(imag(y(1:N)))
hold on; grid on; zoom on;
ylim([-1,1]);
plot(imag(z((1+D):end-1)), 'm');

plot_psd2(y(1:N), z((1+D):end-1), Fs, Nfft);