clear;

%Routine to calculate the number of operations per baseband sample

numFilterTaps = 32;
decimation = 64;    %IF to baseband decimation


for  numChannels = 1:decimation
    
%Wideband DDC Calculation    
%At IF, 2 multiplies, 2 pointer increments, 2 DDS table look ups, 64 filter multiplies, 64 filter adds, 64 shifts
%Note that decimation of 64 is not realistic here, but is done to maintain the integrity of the comparison
WB_DDCOps(numChannels) = numChannels *(2 + 2 + 2 + 64 + 64 + 64) * decimation;


%Narrowband DDC Calculation (3 stage CIC filter)
%At IF, 2 multiplies, 2 pointer increments, 2 DDS table look ups, 2 shifts, 
%18 CIC ops, 1 pointer increment, 1 compare (for decimate counter)

%At baseband: 18 CIC ops, 64 filter multiplies, 64 filter adds, 64 shifts

NB_DDCOps(numChannels) = numChannels *(((2 + 2 + 2 + 2 + 2 + 18 + 1 + 1) * decimation) + 18 + 64 + 64 + 64);


%FDF Calculation
FFTSize = 4096;
overlap = .5;

%baseFFTCalcs = FFTSize * log2(FFTSize) * (1 + overlap);

%baseFFTCalcs = FFTSize * log4(FFTSize) * (1 + overlap);
baseFFTCalcs = FFTSize * 6 * (1 + overlap);

iFFTSize = FFTSize/decimation;

sampsPerBlock = iFFTSize * overlap;

%Number of ops = base number of ops for FFT, plus number of channels times 
%the size of the filter (32 taps plus zeros to reach iFFT size) plus the inverse
%FFT all deviced by the number of samples per block (frequency and phase corrections 
%can be integrated in with the carrier recovery algorithm
FFTOps(numChannels) = baseFFTCalcs + (numChannels * ( iFFTSize + (iFFTSize * log2(iFFTSize))/ sampsPerBlock));

%ZIF Calculation

end

%Polyphase FFT calculation

%assume 32 pole filter for each phase in polyphase filter 
FFTSize = numChannels;
PolyOps(1:numChannels) = numChannels * (32 + 32 + 32) + FFTSize * log2(FFTSize);

WB_DDCOps(1)
NB_DDCOps(1)
FFTOps(1)
PolyOps(1)

plot((1:numChannels), WB_DDCOps, '-', (1:numChannels), NB_DDCOps, ':', (1:numChannels), FFTOps, '-.', (1:numChannels), PolyOps, '--');
axis([1 64 1 200000]);

ylabel('Operations per Baseband Sample')
xlabel('Number of Channels')
Legend('Wideband DDC', 'Narrowband DDC', 'Frequency Domain Filtering', 'Polyphase Filter Bank');