I want to know about wireless wifi signal booster / repeater?

I am using TP Link 150Mbps Wireless N ADSL2+ Modem Router ( TD-W8151N ). But it gives just 1 wifi signal in my room. I have been replaced antenna, now it has 8dbi antenna but still same signals. I heard about wifi signal booster / repeater / access point / bridge system. Now i want to go for that but that 2nd device for signals i want to attach with my ADSL2+ Modem Router via wifi, i dont want to attach that via wire. Can any one tell me is that possible if yes then which device i should get and is that supported my TP Link 150Mbps Wireless N ADSL2+ Modem Router ( TD-W8151N )? Thanks in advance.