Impact of spectrum aggregation technology and frequency on cellular networks performance

Spectrum Aggregation (SA) technology has been introduced in cellular standards: Long Term Evolution (LTE)-Advanced is expected to aggregate multiple Component Carriers (CC) to fulfill the high data rate requirement. In this paper, we use simulation to compare the performance of a cellular system using spectrum aggregation to systems that operates carriers independently, and to systems with contiguous spectrum. We vary a large number of assumptions to generate a comprehensive picture of spectrum aggregation´s impact on cellular network performance. Under spectrum aggregation, users are assigned resource blocks from across all carriers. For Independent Carrier (IC) systems we model a simple carrier selection technique, which assigns a single carrier to each user. To fully understand the impact of SA, spectrum allocation is varied from contiguous to fragmented carriers across bands ranging from UHF to 2.6 GHz. This creates multiple network scenarios including intra-band and inter-band spectrum aggregation systems. Results show that LTE systems that use spectrum aggregation over fragmented blocks of spectrum can have better performance compared to independent carrier systems. Moreover, at low inter-site distances, the performance of inter-band SA is equivalent to that of contiguous low band spectrum, and superior to contiguous high band spectrum.