Don't use Wifi.
Seriously, the Console doesn't support the protocols required to make Wifi good. You would need the ability to take advantage of AC and band steering. Technically, so will most of your other devices using Wifi, and your modem/router will as well.
Wifi can only handle so much bandwidth, and most ISP provided equipment doesn't have the overhead to handle a heavy traffic flow on top of that.
It's not technically an issue with the client. Yes the client does use more bandwidth than most other games, but not significantly enough that it's an issue. Well, it's not an issue if you aren't using airwaves.
I used to run into this when I worked the service desk all the time. Think of it this way.
10Mbps = Your base internet speed.
5Mbps = Your internet speed on Wifi.
(Because of limitations in how the wireless traffic is managed.)
3Mbps = Your internet speed on Wifi after the data is being encrypted and encapsulated.
(Common when using VPN or playing online games.)
So basically because you're using Wifi instead of a cable, you just killed your internet bandwidth by about 70%. Now you've got someone else streaming media on that same bandwidth, and it's going to get cut even further. Not to mention that most modems are designed to give that streaming media bandwidth priority.
TL;DR... It's not an issue with the game. It's an issue with using Wifi.
Here's an article on some things you can do to improve the Wifi signal.
http://www.cheatsheet.com/gear-style/7-ways-to-improve-the-wi-fi-signal-in-your-home.html/?a=viewall
Just be well aware going in that you can't make a Pinto run as well as the Corvette. You can improve the Pinto some, but it's not going to be significant.
(And for those completely thrown off by the car reference, the Pinto is your Wifi, the Corvette is a wired connection.)