How bad is interference in IEEE 802.16e systems?

This paper presents a performance model for dynamic resource allocation in cellular deployments of IEEE 802.16e-like systems. More specifically, we derive a framework which allows to quantify the number of VoIP calls that can be supported in downlink of such systems purely based on the average SINR per terminal. The major difficulty to overcome is to predict the impact of dynamic resource allocations on the system performance in the presence of interference. We show that dynamic resource allocations perform a transformation of subcarrier SINR PDFs and derive an approximate, closed-form representation of these SINR PDFs. Based on these derivations, we derive rate PMFs which predicts system performance up to a gap of about 25% compared to optimal system performance. Furthermore, the model allows for detailed investigation of dynamic resource allocation in interference-limited scenarios. We show that the average SINR is not a valid metric to predict system performance from, but instead the received power of the signal of interest is much more important (together with the received interference power). To the best of our knowledge, such performance models are novel while the presented insights have significant consequences for network design and network self-optimization.