There are devices/standards that can fix this, but the PS4 doesn't support them directly.
If you're unable to connect directly to your router, the best thing to do would be to get a Wireless AC router and a second Wireless AC access point, running on the 5 GHZ band. Plug your PS4 into the second access point via Ethernet, and assuming you're not super far away, you will get throughput equivalent to wired.
Example:
https://www.amazon.com/RT-AC88U-Wireless-AC3100-AiProtection-Complete-Security/dp/B00MPI5N7U/ref=sr_1_1?s=pc&ie=UTF8&qid=1496722092&sr=1-1&keywords=asus+rt-ac88u&th=1
This is pricer equipment, but it's the only way to do this and get proper results.
The new AC standards support simultaneous upload and download, multiple antennas, and a ridiculous amount of optimization that eliminates many of the pitfalls of wireless g/etc. when used correctly. Anyone saying they can tell whether you're on AC or wired when used correctly is 100% lying.
Eventually consoles will support this stuff, but for now this is the best workaround if you're in a pinch.