In vedanta, the consciousness alone in the waking state becomes the waker. The one consciousness which experience is the waking, dreaming and deep sleep. Vedanta says if this is not really you, the real u is hidden behind the wAKER. It's like a person who opens the door of a shop and transacts business before going to bed.
Swami Sarvapriyananda teaches one of the shortest and most profound upanishads accompanied by Gaudapada's Karika. This lecture covers Mantra 1.