Some communal systems can be o very high quality and give you no problems.While others are your worst nightmare.
No1 council communal systems tend to be some of the worst going,done on a budget in the first place,by the lowest bidder
Another threat to council is the yobs living on these estates who smash open the distribution boxes and either break something or nick something.
On the other hand if you live in a privately owned flat complex with say sky,dab/fm radio and of course TV then you can approach the landlord to give the problem a good airing,and get it sorted out.
The other possibility is to simply put your own dish or aerial up but this isn't always possible.