Optimizing OFDM Downlink Performance on LMDS System

Local multipoint distribution service (LMDS) is one of the transmission solutions for broadband applications. LMDS operates in millimeter band using and provides high bitrates services up to 40 Mbps. However, LMDS implementation in tropical countries as in Indonesia deals with rain intensity which introduces high transmission loss. In order to improve the performances of LMDS services in rainy environment, an adaptive power allocation (APA) technique is integrated. APA is a cross-layer technique which optimizes power allocation among users with fixed subcarrier division. The simulations show that the technique improves transmission capacity 9.8% in average, data rate 13.79% in average, utility 25.27% in average and fairness 25.3% in average for rain loss 30dB.