This paper compares the system level performance of Decode-and Forward (DF) relay and a RF repeater in a cellular system. The results show that for small cell sizes, the repeater system can bring higher cell spectrum efficiency gain than the relay system since repeaters in contrast to the relays are assumed to be able to receive and transmit at the same time. However, for larger cell sizes, the relay system can bring higher cell spectrum efficiency gain than the repeater system thanks to the possibility of simultaneous transmission by both the access point and relay node through employment of channel reuse. Irrespectively of cell size, simultaneous transmission by access point and relay node also implies that relays can provide higher system and user throughput than RF repeaters.
