ds_walsh_modulation_demodulation.m

构建CDMA通信系统

<matlab> Walsh序列扩频调制解调的实现
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%                                                                                              %
%  函数通过输入信号序列和函数序号，以及调制解调选择参数来           %
%  完成扩频调制解调。original_seq是原始输入序列，可能是未             %
%  调制序列，也可能是调制序列，walsh_num是walsh函数的序号         %
%  select选择对输入的序列进行调制还是解调。                                 %
%                                                                                              %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [sequence] = DS_walsh_modulation_demodulation(original_seq,walsh_num,select)
if nargin < 2                                       
    error('输入参数不足!');
end
if length(original_seq) < 1
    error('原序列输入错误，无法进行扩频调制！');
end
walsh_sequence = walsh_sequence_generator(64);
walsh_seq = walsh_sequence(walsh_num+1,:);
or_len = length(original_seq);
len = length(walsh_seq);
if select == 1                                      % 进行扩频调制
    mo_seq = walsh_seq.'*original_seq;
    sequence = reshape(mo_seq,1,len*or_len);
else                                                   % 进行扩频序列的解调操作
    de_seq = reshape(original_seq,len,or_len/len);
    sequence = walsh_seq*de_seq/len;
end