Hello Sameh,
According to the documentation the Aironet 3700 will have full autonomous support with the next autonomous release 8.0 which will be target for July, 2014 approximately. Be aware that this date may change.
Today the 7.6 autonomous image supports site survey on the 3700.
Hopefully this information helps you.
Best Regards,
Cristina Alvarado
Global Virtual Engineering - Partner Help.