classdef PAMmapper_test < matlab.unittest.TestCase
    
    properties
        Digi_Mod
        Tx_bits
        Rx_bits
        % M = 8; % Modulation order
        fsym = 112e9; % Symbol rate
        
    end

    properties (TestParameter)
        M = {4,6,8};
    end
    
    methods (TestMethodSetup)
        function setupModulation(testCase)
            % Setup PRBS and bit pattern for the test case
            O = 10; % Order of PRBS
            N = 2^(O-1); % Length of PRBS
            useprbs = 1; % Flag to use PRBS
            randkey = 1; % Random key for random stream

            [~, seed] = prbs(O, 1); % Initialize first seed of PRBS
            bitpattern = [];
            if useprbs
                for i = 1:log2(testCase.M)
                    [bitpattern(:, i), seed] = prbs(O, N, seed);
                end
            else
                s = RandStream('twister', 'Seed', randkey);
                for i = 1:log2(testCase.M)
                    bitpattern(:, i) = randi(s, [0 1], N, 1);
                end
            end

            if testCase.M == 6
                bitpattern = reshape(bitpattern, [], 1);
                bitpattern = bitpattern(1:end-mod(length(bitpattern), 5));
            end
            
            testCase.Tx_bits = Informationsignal(bitpattern);
            testCase.Digi_Mod = PAMmapper(testCase.M, 0);
        end
    end
    
    methods (Test)
        function testBackToBackMapping(testCase)
            % Test Bits -> Symbols -> Bits (Back-to-Back Mapping)

            % Map bits to symbols
            Symbols = testCase.Digi_Mod.map(testCase.Tx_bits);
            
            % Demap symbols back to bits
            testCase.Rx_bits = testCase.Digi_Mod.demap(Symbols);
            
            % Validate BER is zero
            [~, error_num, ber, ~] = calc_ber(testCase.Tx_bits.signal, testCase.Rx_bits.signal, ...
                "skip_front", 0, "skip_end", 0, "returnErrorLocation", 1);

            % Assert that BER is zero
            testCase.verifyEqual(ber, 0, 'BER should be zero');
            testCase.verifyEqual(error_num, 0, 'No errors should occur in the mapping process');
        end
    end
    
end