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This paper proposes a new scheduling algorithm for Long Term Evolution (LTE) downlink systems called Composite Scheduler (CMP) for offering simultaneously Real Time (RT) and Non-Real Time (NRT) applications resources. CMP algorithm dynamically controls channel resources in a manner which reduces packet drop in an overloaded system while still guaranteeing delay bounds and high throughput of real-time services a problem inherent in the Earliest Deadline First (EDF) scheduler. The CMP is obtained by modifying the EDF scheduling algorithm using natural logarithm, number of RT users and LTE Quality of Service (QoS) Class Identity (QCI) priority index which reduces the domino effect experienced by the scheduler during overload. Simulation was done using LTE-Sim with varying number of users ranging from 5 – 60 in a cell radius of 2 km and each user receiving one video, one Voice over Internet Protocol (VoIP), one infinite buffer and one Internet Protocol (IP) Multimedia Subsystem (IMS) flow simultaneously. The proposed algorithm is evaluated against Proportional Fair (PF), EDF and Modified Largest Weighted Delay First (MLWDF) scheduling algorithms for real-time services. The result shows great increase in spectral efficiency by about 10%, 21% decrease in packet loss, an improved fairness of 12%, low delays by 75 ms and 10 times increase in throughput for RT services when compared to normal EDF scheduler.
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