Hi,
Here's what worked for my Acer Aspire V5-552P-X637 (also listed as V5-552P-X440) / Windows 8.1 with the same network adapter. First I uninstalled the driver because I was going to use one of the driver downloads posted here. Instead of using a driver download, in the Device Manager I right clicked on "Network Adapters" and selected "Scan for Hardware..." from popup menu. Network adapter reappeared as device, right clicked it and selected "Update driver software" > "Browse my computer for driver software" > "Let me pick from a list of Drivers on my computer" > there are two drivers listed by default, I selected the second driver and clicked next to install. My laptop hasn't disconnected since!
Before my the driver properties were:
Driver Provider: Microsoft
Driver Date: 5/3/2013
Driver Version: 3.0.1.155
Digital Signer: Microsoft
Now it is updated to below and has not disconnected once:
Driver Provider: Qualcomm Atheros Communications Inc.
Driver Date: 3/11/2013
Driver Version: 10.0.0.234
Digital Signer: Microsoft Windows Hardware Compatibility Publisher
Below are additional steps I took and didn't help prior to changing the driver. I'm not sure if they are necessary but I made sure these steps were still in effect after the driver was changed:
Disable/uncheck the "Allow this computer to turn off this device to save power" option under the Power Management tab of device properties.
AND change the settings here: Control Panel\All Control Panel Items\Power Options\Edit Plan Settings
Click "Change advanced power settings" > select Balance in drop-down menu > click "Wireless Adapter Settings" > "Power Saving Mode" > click "On Battery" > select "Maximum Performance" then click Apply button.
Also repeat these steps for Power Saver option in the drop-down menu.
Hope this is helpful!