An adaptive pilot density based data rate enhancement of mobile WiMAX

Abstract

Today’s era demands a high data rate internet facility. Mobile WiMAX system, provides a high speed internet service. It incorporates the pilot signal at transmitter sides to get link information at receiver.  Present  WiMAX system is based on fixed pilot density approach. Transmission of pilot signals reduces the data rate and bandwidth efficacy of the system. This paper addresses the issue of fixed pilot density approach and  suggests incorporation of variable number of pilot subcarriers based on selected baseband modulation scheme. Implemented system is assessed for bit error rate performance. Simulation results depicts that an adaptive pilot density approach gives BER performance comparable to fixed pilot density method. The system achieves a 7.81 % and 6.25 % improvement in data transmission rate when the QPSK and 16QAM,64QAM baseband modulation schemes are chosen respectively.