  In this paper, we investigate optical wireless repeaters as relay terminals
between a transmitter and a user in an Infrared Optical Wireless Communication
(IROWC) system. A delay adaptation method is introduced to solve the problem of
irregular signal arrival time from different relay terminals. Three different
relay terminal deployment scenarios were investigated in a typical two-phase
relay IROWC system with the proposed delay adaptation method. The simulation
results indicate that the proposed system has better impulse response compared
to the conventional system and that the root-mean-square delay spread of the
relay system with the delay adaptation method is on average 30% less than the
conventional system.
