I think he is barking because he is ready to start his day....................not that you are at that time of the morning. You will find that many dogs that sleep outside are up with the birds (also dogs that are fed in the morning). They are up, so should everyone else.
Personally, my two sleep inside and are fed of a night, so they are last out of bed in our house. They go out during the day when I go to work.
It's a tough one....goodluck sorting it out.