First you must connect your device via USB
Then connect your device to WIFI and get the IP address.
While still connect via usb type this in command line or via Android Studio Terminal
adb tcpip 5555
adb connect :5555
You will see these messages:
restarting in TCP mode port: 5555
connected to 172.11.0.16:5555
Now remove the USB cable and you will still see your logcat as normal
Done. Enjoy