MATLAB Implementation of Alamouti Scheme for MIMO Systems

For implementing the Alamouti scheme in MIMO (Multiple-Input Multiple-Output) systems, the following MATLAB program can be used to demonstrate the complete transmission and reception chain:

```matlab

% System parameter configuration

Nt = 2; % Number of transmit antennas

Nr = 2; % Number of receive antennas

% Generate transmit signals using random binary data generation

s1 = randi([0, 1], Nt, 1); % Signal for first transmit antenna

s2 = randi([0, 1], Nt, 1); % Signal for second transmit antenna

S = [s1, s2]; % Transmit signal matrix formation

% Alamouti encoding implementation - space-time block coding technique

X = [S, -conj(S(:, 2)), conj(S(:, 1))]; % Alamouti encoded matrix with conjugate operations

% Simulate Rayleigh fading channel using complex Gaussian distribution

H = (randn(Nr, Nt) + 1i*randn(Nr, Nt))/sqrt(2); % Channel matrix with normalized variance

% Simulate signal transmission through wireless channel

Y = H*X; % Received signal matrix after channel propagation

% Maximum ratio combining (MRC) reception implementation

h1 = H(:, 1); % Channel vector for first receive antenna

h2 = H(:, 2); % Channel vector for second receive antenna

Y1 = h1.*Y(:, 1) + conj(h2).*Y(:, 2); % MRC output for first antenna combining channel conjugate

Y2 = h1.*Y(:, 2) - conj(h2).*Y(:, 1); % MRC output for second antenna with interference cancellation

Y_max_ratio_comb = [Y1, Y2]; % Combined received signal after MRC processing

% Signal decoding using simple sign detection for binary signals

Y_max_ratio_comb_decoded = sign(real(Y_max_ratio_comb)); % Demodulation by extracting real component

% Display decoded results for verification

disp(Y_max_ratio_comb_decoded);

```

This MATLAB implementation provides a complete demonstration of the Alamouti scheme for MIMO systems, including signal encoding, channel simulation, maximum ratio combining reception, and signal decoding processes.