使用csma/ca生成一个基于优先级的在不同节点数量下的能耗MATLAB代码

以下是一个基于优先级的CSMA/CA协议的MATLAB代码示例，它可以在不同节点数量下计算能耗。这个示例中，我们使用了基于二进制指数退避算法的CSMA/CA协议，节点的发送和接收能耗都被考虑在内。

% CSMA/CA with priority-based transmission
% Energy consumption simulation in different node numbers

clear all;

% Set simulation parameters
num_nodes = [10 20 30 40 50]; % number of nodes
packet_size = 100; % packet size in bits
channel_capacity = 1000000; % channel capacity in bits/sec
pkt_interval = 0.01; % packet generation interval in sec
tx_power = 50; % transmit power in mW
rx_power = 10; % receive power in mW
idle_power = 1; % idle power in mW
collision_power = 100; % power dissipated in a collision in mW
T = 10; % simulation time in sec
SIFS = 0.002; % Short Inter-Frame Spacing in sec
DIFS = 0.01; % Distributed Inter-Frame Spacing in sec

% Initialize variables
total_energy = zeros(1,length(num_nodes));
throughput = zeros(1,length(num_nodes));

% Simulation loop for different number of nodes
for n = 1:length(num_nodes)
    % Initialize node parameters
    num_collision = 0;
    num_success = 0;
    energy_consumption = 0;
    num_nodes_curr = num_nodes(n);
    backoff_counter = zeros(1,num_nodes_curr);
    cw_min = 16;
    cw_max = 1024;
    cw = cw_min;
    priority = randi([1 5],1,num_nodes_curr);
    curr_time = 0;
    pkt_gen_time = zeros(1,num_nodes_curr);
    pkt_sent_time = zeros(1,num_nodes_curr);
    pkt_recv_time = zeros(1,num_nodes_curr);

    % Simulation loop for T seconds
    while(curr_time < T)
        % Generate packets at random nodes
        nodes_to_send = find(pkt_gen_time == curr_time);
        for i = 1:length(nodes_to_send)
            node = nodes_to_send(i);
            if(backoff_counter(node) == 0)
                % Check if channel is idle
                if(max(pkt_recv_time) + SIFS + packet_size/channel_capacity + SIFS <= curr_time)
                    % Transmit packet
                    pkt_sent_time(node) = curr_time;
                    energy_consumption = energy_consumption + tx_power*(packet_size/channel_capacity);
                    % Update backoff counter
                    backoff_counter(node) = randi([0 cw-1]);
                    % Update priority
                    priority(node) = priority(node) + 1;
                end
            end
        end

        % Update backoff counter for nodes with non-zero counter
        nodes_with_counter = find(backoff_counter > 0);
        for i = 1:length(nodes_with_counter)
            node = nodes_with_counter(i);
            backoff_counter(node) = backoff_counter(node) - 1;
            if(backoff_counter(node) == 0)
                % Check if channel is idle
                if(max(pkt_recv_time) + SIFS + packet_size/channel_capacity + SIFS <= curr_time)
                    % Transmit packet
                    pkt_sent_time(node) = curr_time;
                    energy_consumption = energy_consumption + tx_power*(packet_size/channel_capacity);
                    % Update backoff counter
                    if(priority(node) == 1)
                        backoff_counter(node) = randi([0 cw_min-1]);
                    else
                        backoff_counter(node) = randi([0 cw-1]);
                    end
                    % Update priority
                    priority(node) = priority(node) - 1;
                else
                    % Channel is busy, increment collisions
                    num_collision = num_collision + 1;
                    energy_consumption = energy_consumption + collision_power;
                    % Update backoff counter
                    if(priority(node) == 1)
                        backoff_counter(node) = randi([0 cw_min-1]);
                    else
                        cw = min(2*cw, cw_max);
                        backoff_counter(node) = randi([0 cw-1]);
                    end
                    % Update priority
                    priority(node) = priority(node) + 1;
                end
            end
        end

        % Receive packets
        nodes_to_recv = find(pkt_sent_time > 0 & pkt_recv_time == 0);
        for i = 1:length(nodes_to_recv)
            node = nodes_to_recv(i);
            if(pkt_sent_time(node) + SIFS + packet_size/channel_capacity <= curr_time)
                % Receive packet
                pkt_recv_time(node) = curr_time;
                energy_consumption = energy_consumption + rx_power*(packet_size/channel_capacity);
                % Update success counter
                num_success = num_success + 1;
                % Update backoff counter
                cw = cw_min;
                backoff_counter(node) = randi([0 cw-1]);
                % Update priority
                priority(node) = priority(node) + 1;
            end
        end

        % Generate new packets
        pkt_gen_time = pkt_gen_time + pkt_interval;

        % Increment time
        curr_time = curr_time + pkt_interval;
    end

    % Calculate total energy consumption and throughput
    total_energy(n) = energy_consumption + idle_power*num_nodes_curr*(T/0.01 - length(pkt_gen_time));
    throughput(n) = num_success*packet_size/(T*num_nodes_curr);
end

% Plot results
figure;
plot(num_nodes, total_energy, '-o');
xlabel('Number of nodes');
ylabel('Total energy consumption (mJ)');
title('CSMA/CA with priority-based transmission');

figure;
plot(num_nodes, throughput, '-o');
xlabel('Number of nodes');
ylabel('Throughput (Mbps)');
title('CSMA/CA with priority-based transmission');

这个代码示例使用了基于指数退避算法的CSMA/CA协议，并实现了基于优先级的传输。在每个节点上，一个随机的优先级被分配，并且在每次发送之前，节点会检查通道是否空闲，并等待一段时间后再发送。如果通道被占用，则会发生碰撞，节点会增加退避计数器并等待更长的时间，以减少碰撞的可能性。

在不同的节点数量下，我们计算了总能耗和吞吐量，并进行了绘图。这个代码示例可以帮助您更好地理解基于优先级的CSMA/CA协议，并计算不同网络规模下的能耗。