ASK,FSK, and PSK coding for matlab?

MATLAB CODE:

%matlab code for digital modulation(ask, fsk and psk)

f=5;

f2=10;

x=[1 1 0 0 1 0 1 0] % input signal ;

nx=size(x,2);

i=1;

while i<nx+1

     t = i:0.001:i+1;

    if x(i)==1

       ask=sin(2*pi*f*t);

       fsk=sin(2*pi*f*t);

       psk=sin(2*pi*f*t);

    else

        ask=0;

        fsk=sin(2*pi*f2*t);

        psk=sin(2*pi*f*t+pi);

    end

    subplot(3,1,1);

    plot(t,ask);

    hold on;

    grid on;

    axis([1 10 -1 1]);

    title('Amplitude Shift Key')

    subplot(3,1,2);

    plot(t,fsk);

    hold on;

    grid on;

    axis([1 10 -1 1]);

    title('Frequency Shift Key')

    subplot(3,1,3);

    plot(t,psk);

    hold on;

    grid on;

    axis([1 10 -1 1]);

    title('Phase Shift Key')

    i=i+1;

end

 OUTPUT:

FOR MORE DETAILS CLICK HERE

what is OFDM index modulation?

OFDM:

    multi carrier transmission has become an  attractive technique in many wireless standards to meet the increasing demand for high data rate communication systems. One of the most popular multicarrier techniques, orthogonal frequency division multiplexing (OFDM), has developed into a widely-used scheme for wide band digital communication. The major advantage of OFDM over single-carrier schemes is its ability to cope with frequency-selective fading channel with only one-tap equalizer. modulation index of a signal will vary as the modulating signal intensity varies. However some static values enable the various levels to visualised more easily.

                                                    Fig: OFDM with index modulation


an OFDM with generalized index modulation (OFDM-GIM). The generalization is proposed in two aspects. First, a more flexible selection of active sub carriers is proposed to further improve the spectral efficiency.We also demonstrate that the two generalization schemes are compatible with each other and their combined scheme greatly outperforms existing works in spectral efficiency and BER performance, at the cost of a little higher complexity.


FOR MORE DETAILS:

GENERALIZATION OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING WITH INDEX