A performance comparison of LTE downlink scheduling algorithms in time and frequency domains

A number of scheduling algorithms for LTE downlink have been proposed and evaluated leveraging the flexibility of the resource allocation in both the time and the frequency domain. However, the existing literature falls short when it comes to schedulers that provide throughput guarantees. In this paper, we contribute to fill this gap by implementing a scheduling algorithm that provides long-term throughput guarantees to the different users, while opportunistically exploiting the instantaneous channel fluctuations to increase the cell capacity. We perform a thorough performance analysis comparing this algorithm with the other well known algorithms by means of extensive ns-3 simulations, both for saturated UDP and TCP traffic sources. The analysis makes it possible to appreciate the difference among the scheduling algorithms, and to assess the performance gain, both in terms of cell capacity and packet service time, obtained by allowing the schedulers to work in the frequency domain.