Energy-Efficient Resource Scheduling Within DRX Cycles for LTE-A Networks With Carrier Aggregation

For the future-generation wireless communications, the carrier aggregation (CA) of third generation partnership project (3GPP) long-term evolution-advanced (LTE-A) is one of the most promising technologies, which can support significant high data rates over wide frequency bandwidths for various real-time services/applications. To reduce the energy consumption, the LTE-A standard defines the discontinuous reception (DRX) mechanism that allows user equipments (UEs) to turn off radio interfaces when no data is expected to be received. However, how to allocate resource optimally within the DRX cycle for UEs with the CA technology is still an open issue. In this paper, we address the resource scheduling with CA within the DRX cycle, with an objective that maximizes the spectrum utilization while minimizes UE wake-up time. We formulate this problem and propose an energy-efficient iterative heuristic. Our scheme consists of two phases; the first phase determines the scheduling order of component carriers (CCs) to improve the resource efficiency, whereas the second phase minimizes UEs' unnecessary wake-up periods by optimizing their resource intervals from different CCs. Extensive simulation results show that our scheduling achieves better performance than the existing schemes.