bluetooth modulation process

to understand Frequency hoping spread spectrum, its is necessary to understand how spread spectrum technology works.
In spread spectrum , all you do is- spread your signal onto a very high frequency carrier wave form at the transmitter and retrieve the same at the receiver. The trick is - not only you, all other users will use the same bandwidth. The only way in which the receiver can know who you are - is by using some kind of pin to detect your signal. Your carrier wave is generated using this code and transmitted.
At the receiver, we multiple the same carrier wave to generate the original signal.

Now coming to FHSS,
the name itself says. it involves something like frequency and hopping. Here, our data signal will use single frequency of the complete carrier band and keep hopping to a different frequency.the way in which your signal hops over the carrier frequency is determined by a code. The code is such that no two users use same frequency to trasmit at any given time. So in a sense you are achieving orthogonality here.