Repeating or Relaying in Wireless Systems

In this paper, we investigate delay diversity in Ricean fading channels implied by repeaters as a simple form of relay. We will outline the impact in broadcast and in mobile radio systems. Both systems investigate repeater or relaying as a gap filler to increase coverage. Repeaters have the advantage that existing systems will not be affected as there is no additional scheduling for the amply and forward unit needed. Without careful planning these gaps could be emphasized or new gaps could be created. Ray tracing tools take into account the actual SNR, but not the K factor of a Rice channel. Latter is a factor which could effect the coverage as relays are not necessarily beneficial.