%?HuaWei?5G非正交多址方案SCMA仿真
clear;
rng（3）;

frame_num?=?1000;
iter_num?=?10;???%?3~15
M?=?2;??????????%?2/3/4

S?=?[
????1?1?1?0?0?0
????2?0?0?1?1?0
????0?2?0?2?0?1
????0?0?2?0?2?2];??????????????????%?SCMA簽名矩陣

%?調制圖案
switch?M
????case?2
????????mod_map?=?[1?1;?1?-1;?-1?1;?-1?-1]/sqrt（2）;
????case?3
????????mod_map?=?[1?0;?0?1;?0?-1;?-1?0];
????case?4
????????mod_map?=?[1+1i?1+1i;?1-1i?1-1i;?-1+1i?-1+1i;?-1-1i?-1-1i]/2;
end

N?=?4;?????????????????????????????%?校驗節點數量
K?=?6;?????????????????????????????%?信息節點數量
sigma2?=?1;
search_space?=?fullfact（[4?4?4]）;??%?全搜索空間
search_depth?=?4*4*4;??????????????%?搜索空間大小

err_tb_cnt?=?0;
for?frame_id?=?1:frame_num
????
????frame_id
????
????user_num?=?6;
????snr?=?randi（[4?20]?user_num?1）;
????h?=?sqrt（db2pow（snr））.*exp（1i*2*pi*rand（user_num1））;??%?隨機生成信道
????
????tx_data?=?0;
????for?ueid?=?1:user_num
????????index（ueid）?=?randi（[1?4]）;
????????data?=?mod_map（index（ueid）:）;
????????tmp?=?zeros（41）;
????????tmp（S（:ueid）==1）?=?data（1）;
????????tmp（S（:ueid）==2）?=?data（2）;
????????tx_data?=?tx_data?+?h（ueid）*tmp;
????end
????
????y?=?awgn（tx_data?0）;??????%?AWGN信道
????
????Q?=?1/4*ones（NK4）;???????%?初始化信息節點到校驗節點的傳遞信息
????R?=?1/4*ones（NK4）;???????%?初始化校驗節點到信息節點的傳遞信息
????
????for?iter?=?1:iter_num
????????for?n?=?1:N
????????????k?=?find（S（n:）~=0）;
????????????tone_idx?=?S（nk）;
????????????tmp_h?=?h（k）;
????????????p?=?zeros（search_depth?1）;
????????????for?m?=?1:search_depth
????????????????x?=?diag（mod_map（search_space（m:）?tone_idx））.‘*tmp_h;
????????????????p（m）?=?Q（nk（1）search_space（m1））?...
????????????????????*?Q（nk（2）search_space（m2））?...
????????????????????*?Q（nk（3）search_space（m3））?...
????????????????????*?1/（pi*sigma2）*exp（-abs（y（n）-x）^2/sigma2）;
????????????end
????????????p?=?p/sum（p）;
????????????
????????????for?ii?=?1:3
????????????????for?m?=?1:4
????????????????????idx1?=?search_space（:ii）==m;
????????????????????R（nk（ii）m）?=?sum（p（idx1））;
????????????????end
????????????end
????????end
????????
????????for?k?=?1:K
????????????for?n?=?1:N
????????????????flag?=?S（:k）~=0;
????????????????flag（n）?=?0;???????%?去掉本校驗節點
????????????????p?=?zeros（41）;
????????????????p（1）?=?prod（R（flagk1））;
????????????????p（2）?=?prod（R（flagk2））;
????????????????p（3）?=?prod（R（flagk3））;
????????????????p（4）?=?prod（R（flagk4））;
????????????????p?=?p/sum（p）;
????????????????Q（nk:）?=?p;
????????????end
????????end
????end
????
????tmp?=?prod（R）;
????[~result]?=?max（tmp?[]?3）;
????
????err_tb_cnt?=?err_tb_cnt?+?~all（index==result）;
end

err_tb_cnt

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-12-23?12:25??SCMA\
?????文件????????2747??2018-12-23?12:25??SCMA\main.m
?????文件????????1179??2018-12-23?12:25??SCMA\SCMA.zip