本文讨论了QPSK在Rayleigh信道中的误码率性能，包括理论Rayleigh模型和AWGN（Additive White Gaussian Noise）下的误码率，并与仿真结果进行了比较。模拟信号通过瑞利信道进行调制并添加AWGN。然后对Rayleigh信道进行分频解调，并对误差进行统计，得到QPSK的误码率性能
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001027s ]
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:0.108790s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.015193s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001162s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001041s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003214s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000899s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003557s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014657s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001151s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 24820 [ RunTime:0.024875s ]
