Google Incorporated is getting ready to bid on a wireless spectrum in a Federal Communications Commission auction in January and is prepared to do so without any partners, according to people familiar with the situation. Google is working out a plan to finance its bid (which could run to $4.6 billion or higher) that would rely on its own cash and possibly some borrowed money. The search giant is currently running a test version of an advanced wireless network at its Mountain View, California headquarters, gaining operating experience that could come in handy if it wins the spectrum and decides to run a full-scale national mobile carrier. If the company goes through with the purchase, it would be more expensive than any acquisition that Google has previously paid for.