%This function generates the base-band signal for the input symbols

%Input Parameters:-
%Symbols : Symbols to be converted to Inphase and Quadrature signals
%RRC_Filter_Coeff: Coefficients of the RRC filter
%Zi_T_RRC_I: Initial Conditions for the Inphase RRC Filter
%Zi_T_RRC_Q: Initial Conditions for the Quadrature RRC Filter

%Output Parameters:-
%Sig_Inphase : Base-Band Inphase Signal for the input Symbols
%Sig_Quad : Base-Band Quadrature Signal for the input Symbols
%Zf_T_RRC_I: Final Conditions for the Inphase RRC Filter
%Zf_T_RRC_Q: Final Conditions for the Quadrature RRC Filter

function [Sig_Inphase, Sig_Quad, Zf_T_RRC_I, Zf_T_RRC_Q] = Symbols2BaseBand(Symbols, RRC_Filter_Coeff, Zi_T_RRC_I, Zi_T_RRC_Q)
%Paramters Initialization
Parameter;

Sig_Inphase = [];
Sig_Quad = [];

for iSymb = 1 : length(Symbols)
    %Generating impulses for InPhase
    Sig_Inphase_CurSymbol(1:SamplesPerSymbol) = 0;
    Sig_Inphase_CurSymbol(1) = real(Symbols(iSymb));    
    %Generating impulses for Quadrature
    Sig_Quad_CurSymbol(1:SamplesPerSymbol) = 0;
    Sig_Quad_CurSymbol(1) = imag(Symbols(iSymb));
    %Appending the signal
    Sig_Inphase = [Sig_Inphase, Sig_Inphase_CurSymbol];
    Sig_Quad = [Sig_Quad , Sig_Quad_CurSymbol];
end

%Passing the impulses through the RRC Filter
[Sig_Inphase, Zf_T_RRC_I] = filter(RRC_Filter_Coeff, 1, Sig_Inphase, Zi_T_RRC_I);
[Sig_Quad, Zf_T_RRC_Q] = filter(RRC_Filter_Coeff, 1, Sig_Quad, Zi_T_RRC_Q);