If you are referring to being in Settings>WiFi and seeing "SEARCHING" displayed about every 10 seconds, then there is nothing you can do about it...that's the way this phone works. My guess is that all phones (at least all on 5.x) work this way, but most probably don't display the message. I can tell you that it doesn't appear to effect the phone's battery, as mine (and most others here) get a solid days usage out of the device.
If I've misunderstood you, and your problem is not as I described, I guess you need to reword what the problem is.