I've got primary router that handles the connection out to the internet, acts as a switch and broadcasts a fairly weak wifi signal. This is connected to a decent 200Mbps powerline adapter which comes out in another part of the house. The far end of the powerline adapter connects to a 5-port gigabit switch.
The problem is that the wifi signal is terrible in the room that has the gigabit switch, so I'm looking to get something to improve the signal. Ideally, this something would have the same SSID and setup as the main wifi router, so that wireless devices in my home can just connect to whichever is closest seamlessly.
From the research I've done, it seems I want some kind of repeater, but from what I've read most repeaters just use the weak wireless signal they can pick up and rebroadcast it stronger. I'd guess that I'd get a faster and more reliable connection if I could somehow make use of powerline adapter and switch set-up for this, rather than eventually ultimately routing through the weak wifi signal.
The current switch has a single ethernet port free to connect another device. What device(s) should I connect? I'm happy to either put something in the free ethernet slot purely to improve the wifi signal, or I'm happy to replace the entire switch (I'd still need at least 4 ports).