[Show abstract][Hide abstract] ABSTRACT: Recently, the integration of orthogonal frequency division multiplexing (OFDM) and radio over fiber (RoF) technique emerged the possibility of cost-effective and high data rate wireless network (WiMAX, 4G). However, the nonlinear effects in optical link as well as the multipath fading in wireless transmission can severely degrade the performance of OFDM-ROF system. In this paper, we present a combined adaptive modulation which can combat with both the nonlinear effects and frequency-selected fading. Simulation results show better BER performance compared to conventional modulation schemes.
[Show abstract][Hide abstract] ABSTRACT: The current best-effort Internet is adverse to deliver real media information since it is provided with an uncertain delay property in the traditional routing, flow control and retransmission. The research on the access control mechanism is more significant along with the development of the media applications. In this paper, a multi-path access control scheme on cost in core packet network is proposed to make it highly scalable and robust. In which, the scheduling and routing model in core network is presented, and the link cost of core network is calculated, then the optimized route is selected in term of the minimum cost. Simulation results show that the cost provided by this access control scheme would be nearly accordant with the performance of services in the network.