24小时热门版块排行榜    

查看: 1553  |  回复: 6
当前只显示满足指定条件的回帖,点击这里查看本话题的所有回帖

aaron7

铁虫 (初入文坛)

[求助] 一个log-det-sum-exp-matrix函数的凸性研究问题

请问附件里这个f(X1,X2...XN)函数是凸的吗?Xi是厄米特正定矩阵
回复此楼

» 猜你喜欢

» 本主题相关价值贴推荐,对您同样有帮助:

已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

aaron7

铁虫 (初入文坛)

引用回帖:
6楼: Originally posted by acmuser at 2012-05-20 00:52:54:
还有,可以告诉我这个问题的背景吗?

高信噪比下,MIMO信道容量公式可以表示为下图,对Xi怎么进行变换能使这个函数变成concave的呢?比如在SISO情况下Xi和Xj都是标量,可以进行yi=e^xi变形,那么公式就是concave的了,但是矩阵情况下能不能满足呢?谢谢


7楼2012-05-20 14:17:08
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
查看全部 7 个回答

acmuser

银虫 (小有名气)

interesting question, I will think about it when I have time.
2楼2012-05-17 18:51:28
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

aaron7

铁虫 (初入文坛)

引用回帖:
2楼: Originally posted by acmuser at 2012-05-17 18:51:28:
interesting question, I will think about it when I have time.

呵呵 谢谢关注
3楼2012-05-18 09:03:16
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

aaron7

铁虫 (初入文坛)

引用回帖:
2楼: Originally posted by acmuser at 2012-05-17 18:51:28:
interesting question, I will think about it when I have time.

A1=rand(2,2)+i*rand(2,2)
A2=rand(2,2)+i*rand(2,2)
A1=A1*A1'
A2=A2*A2'
B1=rand(2,2)+i*rand(2,2)
B2=rand(2,2)+i*rand(2,2)
B1=B1*B1'
B2=B2*B2'
t=0.3
a1=t*A1+(1-t)*B1
a2=t*A2+(1-t)*B2
ans1=log2(det(expm(a1)+expm(a2)))
ans2=t*log2(det(expm(A1)+expm(A2)))+(1-t)*log2(det(expm(B1)+expm(B2)))
这是仿真代码
4楼2012-05-18 09:38:56
已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[考研] 26考研报考西工大材料308分求调剂 +3 weizhong123 2026-03-01 3/150 2026-03-01 21:42 by 公瑾逍遥
[考研] 一志愿郑大材料学硕298分,求调剂 +3 wsl111 2026-03-01 3/150 2026-03-01 21:38 by ms629
[考研] 0856求调剂285 +10 吕仔龙 2026-02-28 10/500 2026-03-01 21:37 by 公瑾逍遥
[考研] 274求调剂 +3 cgyzqwn 2026-03-01 6/300 2026-03-01 21:24 by cgyzqwn
[考研] 299求调剂 +3 Y墨明棋妙Y 2026-02-28 5/250 2026-03-01 21:01 by tangxiaotian
[考研] 272求调剂 +6 材紫有化 2026-02-28 6/300 2026-03-01 18:58 by 18137688336
[考研] 材料学调剂 +9 提神豆沙包 2026-02-28 11/550 2026-03-01 18:15 by ms629
[考研] 328求调剂 +3 aaadim 2026-03-01 5/250 2026-03-01 17:29 by njzyff
[考研] 285求调剂 +8 满头大汗的学生 2026-02-28 8/400 2026-03-01 16:47 by caszguilin
[考研] 311求调剂 +6 亭亭亭01 2026-03-01 6/300 2026-03-01 15:41 by 324616
[考研] 求调剂 +6 repeatt?t 2026-02-28 6/300 2026-03-01 14:37 by Sakura绘
[考研] 295复试调剂 +3 简木ChuFront 2026-03-01 3/150 2026-03-01 14:27 by zzxw520th
[考研] 284求调剂 +6 天下熯 2026-02-28 6/300 2026-03-01 14:19 by Ducount.Y
[考研] 调剂 +3 简木ChuFront 2026-02-28 3/150 2026-03-01 11:46 by 王伟要上岸啊
[考博] 博士自荐 +4 kkluvs 2026-02-28 4/200 2026-03-01 10:19 by 馥安馥安
[论文投稿] Optics letters投稿被拒求助 30+3 luckyry 2026-02-26 4/200 2026-03-01 09:06 by babero
[考研] 307求调剂 +4 73372112 2026-02-28 6/300 2026-03-01 00:04 by ll247
[考研] 304求调剂 +3 52hz~~ 2026-02-28 5/250 2026-03-01 00:00 by 52hz~~
[考研] 276求调剂 +3 路lyh123 2026-02-28 4/200 2026-02-28 19:45 by 路lyh123
[硕博家园] 【博士招生】太原理工大学2026化工博士 +4 N1ce_try 2026-02-24 8/400 2026-02-26 08:40 by N1ce_try
信息提示
请填处理意见