Deleted

03 P1765 Baseline EVM Algorithms/Single_Carrier/F_calculateOptimal.m

-function [tau0, XOutopt] = F_calculateOptimal(XIn, XOut, Ts)
-
-    % Version: 8.27.2020
-    %
-    % 
-    % Function to calculate baseline EVM receiver optimal time delay and
-    % complex normalization based on all time samples (carried out in frequency domain).
-    % See Section 5.1.2.2 Optimal Time Alignment of Waveform 2 to Waveform 1 
-    % and Removal of Constant Phase Offset, and Annex B of IEEE P1765 document.
-    %
-    % Inputs:
-    %   XIn:            Discrete uniform spectra of input waveform with frequency spacing 1/Ts
-    % 	XOut:           Same but for output waveform
-    %   Ts:             Time duration (ns) of input/output time-domain waveforms corresponding to XIn and XOut
-    % 	
-    % Outputs:
-    % 	tau0:           Optimal time delay to be applied in the phase of XOut before same sampling/calculation
-    %   XOutopt:        XOut after optimal time-shifting/normalization
-    % 
-    % Extra outputs:
-    % 	G_0:            Optimal complex gain to be applied to XOut before symbol sampling/EVM calculation
-    %   G_0amp:         abs(G_0)
-    %   G_0phase:       angle(G_0)*180/pi
-    %	optTolerance:   Absolute tolerance determined for iterative delay calculation convergence 
-    %	iterindx:       Number of iterations for optimal delay loop convergence (= 10000 if convergence fails)
-
-    global structGlobal
-   
-    K = length(XIn); 
-    % K is the number of sampling intervals in XIn (which must equal that in XOut)
-    % and also equal to number of time sampling points in Xin and Xout minus one
-    % (last end-sample identified with first one due to periodicity)
-
-    P0 = conj(XIn).*XOut;
-    P1 = P0.*(0:K - 1);
-    P2 = P1.*(0:K - 1);
-    domega = 2*pi/Ts;                                       % Angular frequency spacing of XIn and XOut
-    dt = Ts/K;                                              % Time sampling interval
-   
-    % First coarse alignment based on cross-correlation
-    % See Section 5.1.2.2(1) of IEEE P1765 document: Coarse time alignment
-    R = abs(ifft(P0));
-    [Rmax, Icoarse] = max(R);
-    T0init = (Icoarse - 1)*dt;                              % Coarse delay (within one time sampling interval dt)
-
-    % Fine time alignment
-    % See Section 5.1.2.2(2) of IEEE P1765 document: Fine time alignment 
-    % Parabolic fit refinement
-    if Icoarse ==1 
-        Rleft = R(K); Rright = R(2);
-    elseif Icoarse == K
-        Rleft = R(K - 1); Rright = R(1);
-    else
-        Rleft = R(Icoarse - 1); Rright = R(Icoarse + 1);
-    end
-    T = T0init + (dt/2)*(Rleft - Rright)/(Rleft + Rright - 2*Rmax); % Parabolic fit refined delay estimate
-
-    % Iterative optimal refinement
-    structGlobal.optTolerance = 10*eps(T);                  % MATLAB eps function giving distance from T to nearest double floating 
-                                                            % point number (margin factor of 10 added to reach usable tolerance)
-    domegaT = domega*T;
-    domegadT = 1;
-    domegadTtol = domega*structGlobal.optTolerance;         % Iterative tolerance for domegaT
-    index = 1;
-    while (abs(domegadT) > domegadTtol) && (index < 10001)	% Failsafe loop exit criteria
-       Mc = exp(-1i*(0:K - 1)*domegaT);
-       C0 = dot(Mc,P0);
-       C1 = dot(Mc,P1);
-       C2 = dot(Mc,P2);
-       num = imag(C1*conj(C0));
-       den = real(abs(C1)^2 - C2*conj(C0));
-       domegadT = num/den;
-       domegaT = domegaT + domegadT;
-       index = index + 1;
-    end
-    G_0 = dot(XOut,(XIn.*Mc))/dot(XOut,XOut);  % Optimal complex gain, this variable is not used further per Section 5.1.2.2
-    tau0 = domegaT/domega;                     % Optimal time delay
-    XOutopt = G_0*(XOut.*conj(Mc));            % Optimal time delayed/normalized version of XOut
-    errvecopt = XIn - XOutopt;                 % Error vector of optimal alignment/normalization 
-    errmin = dot(errvecopt,errvecopt);         % Minimum error power between XIn and XOut
-    structGlobal.iterindx = index - 1;         % Number of domegaT loop iterations (= 10000 if convergence fails)
-    
-    structGlobal.G_0amp = abs(G_0);
-    structGlobal.G_0phase = angle(G_0)*180/pi;
-    
-end
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