Wifi Problems on iPhone 4

My iPhone is realtively new, but over the last month I have lost all internet/wifi connection. I am not sure if it is the iOS, the network (EE) or just the phone. I have checked my settings and all is as it should be, but I can't seem to get a connection wherever I go, or even when I'm at home. I've seen that a lot of others seem to be having this problem so if anyone knows the cause or a solution that would be a great help.🙂 Thanks.