classdef PAMmapper
    %PAMMAPPER Summary of this class goes here
    %   Detailed explanation goes here

    properties
        M
        unipolar
        thresholds
    end

    methods
        function obj = PAMmapper(M, unipolar)
            %PAMMAPPER Construct an instance of this class
            %   Detailed explanation goes here
            obj.M = M;
            obj.unipolar = unipolar;

            obj.thresholds = obj.get_demodulation_thresholds();

        end

        function signalclass_out = map(obj,signalclass_in)
            signalclass_in.signal = obj.map_(signalclass_in.signal); 
            signalclass_in  = signalclass_in.logbookentry();
            signalclass_out = signalclass_in;
        end

        function signalclass_out = demap(obj,signalclass_in)
            signalclass_in.signal = obj.demap_(signalclass_in.signal); 
            signalclass_in  = signalclass_in.logbookentry();
            signalclass_out = signalclass_in;
        end

        function pam_sig = map_(obj,bitpattern)

            switch log2(obj.M)
                case 1
                    % 2-ASK: BPSK / OOK
                    pam_sig=bitpattern(:,1);

                    if obj.unipolar==0
                        pam_sig=2*pam_sig-1;
                    end

                case 2
                    % 4-ASK:
                    pam_sig=2*bitpattern(:,1)+(bitpattern(:,1)==bitpattern(:,2));

                    if obj.unipolar==0
                        pam_sig=2*pam_sig-3;
                    end


                case 3
                    % 8-ASK:
                    x1 = bitpattern(:,1);
                    x2 = (bitpattern(:,1)==bitpattern(:,3));
                    x3 = x2~=bitpattern(:,2);

                    pam_sig = 4*x1 + 2*x2 + x3;

                    if obj.unipolar==0
                        pam_sig=2*pam_sig-7;
                    end


                case 4
                    % 16-ASK:
                    x1 = bitpattern(:,1);
                    x2 = (bitpattern(:,1)==bitpattern(:,4));
                    x3 = x2~=bitpattern(:,3);
                    x4 = x3~=bitpattern(:,2);

                    pam_sig = 8*x1 + 4*x2 + 2*x3 + x4;

                    if obj.unipolar==0
                        pam_sig=2*pam_sig-15;
                    end

            end
        end

        function thres =  get_demodulation_thresholds(obj)
            %simply get the obj.thresholdseshold values for PAM

            %28.03.2023 - Silas Oett. - Extracted from digi_demod.m
            %

            obj.thresholds = 0;

            switch log2(obj.M)

                case 1
                    % 2-ASK

                    if obj.unipolar
                        thres=0.5;
                    else %bi polar
                        thres=0;
                    end

                case 2
                    % 4-ASK
                    if obj.unipolar==0
                        thres=[-2,0,2];
                    elseif obj.unipolar==1
                        thres=[0.5,1.5,2.5];
                    end


                case 3
                    % 8-ASK
                    if obj.unipolar==0
                        thres=-6:2:6;
                    elseif obj.unipolar==1
                        thres=0.5:6.5;
                    end

                case 4
                    % 16-ASK
                    if obj.unipolar==0 && scale_mode==1
                        thres=-14:2:14;
                    elseif obj.unipolar==1 && scale_mode==1
                        thres=0.5:14.5;
                    end

            end

        end

        function [data_out] = demap_(obj,data_in)

            data_in= data_in';
            % create output
            if ~isempty(obj.thresholds)
                a = squeeze(repmat(real(data_in),[1 1 length(obj.thresholds)])); %Eingangssignal in 3 spalten
                b = squeeze(repmat(reshape(obj.thresholds(:).',[1 1 length(obj.thresholds)]),[1 length(data_in) 1])); %Threshold in 3 Spalten
                comp_real = a > b; %check for each symbol/ sampling if it exeeds the obj.thresholdseshold 1, 2 or 3

                comp_real=repmat(real(data_in),[1 1 length(obj.thresholds)]) > repmat(reshape(obj.thresholds(:).',[1 1 length(obj.thresholds)]),[1 length(data_in) 1]);

            else
                comp_real=[];
            end

            s1=size(comp_real,1);
            s2=size(comp_real,2);


            switch log2(obj.M)

                case 1
                    % 2-ASK

                    data_out=comp_real(:,:,1);

                case 2
                    % 4-ASK

                    data_out=[comp_real(:,:,2); ones(s1,s2)-comp_real(:,:,1)+comp_real(:,:,3)];


                case 3
                    % 8-ASK
                    data_out=[comp_real(:,:,4);
                        comp_real(:,:,1)-comp_real(:,:,3)+comp_real(:,:,5)-comp_real(:,:,7);
                        1-comp_real(:,:,2)+comp_real(:,:,6)];

                case 4
                    % 16-ASK
                    data_out=[comp_real(:,:,8);
                        comp_real(:,:,1)-comp_real(:,:,3)+comp_real(:,:,5)-comp_real(:,:,7)+comp_real(:,:,9)-comp_real(:,:,11)+comp_real(:,:,13)-comp_real(:,:,15);
                        comp_real(:,:,2)-comp_real(:,:,6)+comp_real(:,:,10)-comp_real(:,:,14);
                        1-comp_real(:,:,4)+comp_real(:,:,12)];
            end


        end

    end

end