与上一个上传源码属同一问题的不同方面，均为用matlab来实现am调制与解调，以及仿真实现。
-From the previous source is the same issue on different aspects, all using matlab to achieve am modulation and demodulation, as well as simulation.
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001189s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.097652s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001173s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001878s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001262s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003636s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001058s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003215s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.021471s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001502s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 76759 [ RunTime:0.001638s ]
