setup 2 htc vive with 2 pc in 2 spot 3m X 3m (one spot near to other one without wall)

[Zakabot]

Hi guys, I'm try to setup 2 htc vive (first gen) with 2 pc in 2 spot 3m X 3m (one spot near to other one without wall). 
My main problem is the controller tracking with the base stations that provide issue.
Is look like the controller was see also from the station from the near spot and is not possible to play at same time because provide a "conflict" and one controller "fly" away.
I got a suggestion to separate the space for block the station signal. 
There are any other way for do this without separate the room?