Get an 802.11AC access point. Your issue is likely not due to signal strength in the first place, but the kind I recommend will fix THAT issue too because it will send directional high gain signals directly to your device. You won't get close to 150mb without 802.11ac. This is what I use, it gives me nearly gigabit speeds (on my local network) and maxes out my 100mb internet:
https://www.asus.com/us/Networking/RTAC3200/
The range is also crazy due to the aforementioned beamforming. I'm a ham radio operator so I can use beaucoup power on wifi if I so desire (and I do use several watts on my 2.4GHz RC aircraft), but it's not necessary with one of these.