write a m file to simulate OAM-OFDM in Matlab

As an AI language model, I am not capable of writing codes in Matlab. However, here is a sample code for OAM-OFDM simulation in Matlab:

%OAM-OFDM Simulation

clc;
clear all;
close all;

%% Initialization
N = 64; % Number of subcarriers
M = 4; % Number of OAM modes
L = N*M; % Total number of subcarriers
P = 16; % Cyclic prefix length
M1 = 2; % Number of bits per symbol
M2 = 2; % Number of bits per OAM mode
SNR = 10; % Signal-to-Noise Ratio
nframes = 100; % Number of OFDM frames

%% Generate OFDM Symbols
for i = 1:nframes
% Generate random data
data = randi([0 1], M1*N, 1);
% Generate OAM mode
oam = randi([0 M-1], M2, 1);
% Modulate data and OAM mode
tx_data = qammod(data, 2^M1);
tx_oam = exp(1j*2*pi*(0:M2-1)*oam/M);
% Combine data and OAM mode
tx_data_oam = kron(tx_data, tx_oam);
% Perform IFFT
tx_ifft = ifft(tx_data_oam);
% Add cyclic prefix
tx = [tx_ifft(N-P+1:N); tx_ifft];
% Save transmitted symbols
tx_symbols(:,i) = tx;
end

%% Add AWGN Noise
% Calculate noise power
noise_power = 10^(-SNR/10);
% Generate noise
noise = sqrt(noise_power/2)*(randn(L+P, nframes)+1j*randn(L+P, nframes));
% Add noise to transmitted symbols
rx_symbols = tx_symbols + noise;

%% Perform OFDM Demodulation
for i = 1:nframes
% Remove cyclic prefix
rx = rx_symbols(P+1:end, i);
% Perform FFT
rx_fft = fft(rx);
% Extract OAM mode
oam_fft = rx_fft(1:M2:end);
oam = angle(oam_fft)*M/(2*pi);
% Demodulate data
data_fft = rx_fft(M2+1:M2:end);
data = qamdemod(data_fft, 2^M1);
% Combine data and OAM mode
rx_data_oam = [data; oam];
% Save received data and OAM mode
rx_data_oam_all(:,i) = rx_data_oam;
end

%% Calculate Bit Error Rate
% Calculate error rate for each frame
for i = 1:nframes
% Extract received data and OAM mode
rx_data_oam = rx_data_oam_all(:,i);
rx_data = rx_data_oam(1:M1*N);
rx_oam = rx_data_oam(M1*N+1:end);
% Demodulate data and OAM mode
rx_data_qam = qammod(rx_data, 2^M1);
rx_oam_exp = exp(1j*2*pi*(0:M2-1)*rx_oam/M);
% Calculate bit error rate
[~, ber(i)] = biterr(rx_data_qam, tx_data);
[~, ber_oam(i)] = biterr(rx_oam_exp, tx_oam);
end
% Calculate average bit error rate
avg_ber = mean(ber);
avg_ber_oam = mean(ber_oam);

%% Display Results
disp(['Average Bit Error Rate: ' num2str(avg_ber)]);
disp(['Average OAM Bit Error Rate: ' num2str(avg_ber_oam)]);