Crosslayer Optimization of User Scheduling and Resource Allocation in Power-Line Communication Systems

This paper considers the cross-layer optimization for orthogonal frequency-division multiple access-based power-line communication systems. The user scheduling in the data-link control layer selects the serving users and ascertains their optimal cross-layer parameters according to each user's quality-of-service (QoS) requirements, QoS satisfaction degree, packet traffic model, channel and queue status information, and rate of transmitted data. The resource allocation in the physical layer assigns subcarrier and power for the scheduling users according to their QoS requirements, correlative cross-layer parameters, and channel status information. Since the multiuser's subcarrier-power allocation is a layered multiobjective mixed-integer nonlinear problem with many practical restrictions, it is first transformed into the multiple simple single-objective problems by using the resource factor. After obtaining each Pareto solution of the used resources based on the resource factor for satisfying the minimal rate of each user, the remaining resources are assigned to the users with a maximal rate without considering the resource factor by using the bit-loading lookup table algorithm. Finally, the optimal solution is selected from the results of resource allocation according to the order of the partial information. Based on the typical power-line channel scenarios, the simulation results illustrate that the proposed algorithm outperforms the existing multiuser algorithms in terms of the multiple aims of resource allocation.