It's almost impossible to set up a home-based radio station, using music content, in the UK.
Whether you do it by broadcast radio or online, you've got the problem of having to pay for broadcasting copyright songs. I don't know what the BBC currently pays but, for their national stations, it's probably hundreds of pounds per track. (Channel 4 currently pay �680 to include a 4 minute track as background music in one of their programmes). Even local radio stations pay quite large fees for every track they play.
The only way you can set up as a home-based broadcaster in this country, is to do it online and avoid using copyright music. That means either playing your own original music (i.e. stuff that you've written yourself and play yourself) or sticking to speech radio.
Actual radio broadcasting (rather than online broadcasting) requires a licence which is extremely difficult to obtain and costs tens (or hundreds) of thousands of pounds. Even if you could get such a licence, it wouldn't exempt you from having to pay to broadcast copyright music.
Chris