For USB 3 devices on the end of a cable
How NOT to place your USB 3 device. Do NOT place it or it's cables near to your Bluetooth devices.
If your USB 3 device needs a cable to sit between the laptop and the device (many do, for example external hard drives) make sure that the cable is fully extended with the device as far away from the laptop as possible.
Also position the USB 3 device/s as far away from your Bluetooth devices as possible. For example; if you have a hard drive, don't have it sitting next to your Bluetooth mouse or keyboard but instead in the opposite direction ideally behind the laptop. If there is a USB 3 hub between the end device and laptop also ensure that this and any cables attached to it are also as far away as possible from your Bluetooth devices.
Recommended: Extend the cable of any USB 3 device as far as possible away from your Bluetooth device/s and use as long a cable as possible to increase distance.
If the device was supplied with a particularly short USB 3 compatible cable then you may want to replace it with a longer one. USB 3 cables can be found up to 3 meters in length so this should give you plenty of distance to better separate the device. Make sure that you buy a quality shielded USB 3 compatible cable.
If you still have problems make sure your USB 3 device is as far away from the computer and any Bluetooth devices as possible. In this shot you can see the USB 3 hard disk is extended on the oposite side of the computer from the Bluetooth mouse
Making use of other USB ports on your laptop
If you still experience problems double check all the USB ports on your Laptop.
Whilst some ports may not be USB 3 you may find that you have other USB 3 ports on the other side or back of the laptop. Try plugging the device into different available USB 3 ports on your laptop. It's possible that the circuitry inside your laptop that contains the Bluetooth receiver is located in one corner of the laptop and that switching the USB port used by your problem USB 3 device from one side of the laptop to the other will resolve the problem.