There are wifi antennas that come with soft ware but they may not work on all makes & models. Hard wiring is always best. If you can't run a wire you can use a wireless bridge or home link adopters that use the existing house wiring to move signal around. You need two to start - one at the router, one by the receiver. If you have a second receiver you only need one more for that.
Here is one usb wifi antenna - see if it will work for you