上面程序显示没有定于cmi_encode

非常抱歉，看来我的回答中缺少了 `cmi_encode` 函数的定义，下面是完整程序，包括 `cmi_encode` 和 `cmi_decode` 两个函数的定义：

% CMI编码和译码的仿真
clc; clear; close all;

% 定义输入序列
input_seq = [0 1 0 1 1 0 1 0 1 0];

% 定义CMI编码的参数
pulse_width = 1; % 脉冲宽度
pulse_spacing = 1; % 脉冲间距

% CMI编码
encoded_seq = cmi_encode(input_seq, pulse_width, pulse_spacing);

% CMI译码
decoded_seq = cmi_decode(encoded_seq);

% 绘制基带信号、编码和译码的波形
t = 0:0.01:length(input_seq); % 时间轴
baseband_signal = kron(input_seq, ones(1, 100)); % 基带信号
encoded_signal = kron(encoded_seq, ones(1, 100)); % 编码波形
decoded_signal = kron(decoded_seq, ones(1, 100)); % 译码波形

subplot(3, 1, 1);
plot(t, baseband_signal, 'LineWidth', 2);
title('Baseband Signal');

subplot(3, 1, 2);
plot(t, encoded_signal, 'LineWidth', 2);
title('Encoded Signal');

subplot(3, 1, 3);
plot(t, decoded_signal, 'LineWidth', 2);
title('Decoded Signal');

% CMI编码函数
function encoded_seq = cmi_encode(input_seq, pulse_width, pulse_spacing)
    encoded_seq = [];
    for i = 1:length(input_seq)
        if input_seq(i) == 0
            encoded_seq = [encoded_seq zeros(1, pulse_width)];
        else
            encoded_seq = [encoded_seq ones(1, pulse_width)];
        end
        encoded_seq = [encoded_seq zeros(1, pulse_spacing)];
    end
end

% CMI译码函数
function decoded_seq = cmi_decode(encoded_seq)
    decoded_seq = [];
    for i = 1:length(encoded_seq)
        if encoded_seq(i) == 0
            decoded_seq = [decoded_seq 0];
        else
            decoded_seq = [decoded_seq 1];
            if i < length(encoded_seq) && encoded_seq(i+1) == 0
                decoded_seq(end) = 0;
            end
        end
    end
end

希望这次回答能够帮助你！