In Heterogeneous networks (HetNet), low-power Small Cells (SCs) can serve a good portion of the mobile users. These users are likely to have good Signal-to-Interference-plusNoise-Ratio (SINR) values, which can be exploited to satisfy the expected demand of huge data rates. In this paper, we investigate the effect of introducing higher order modulation, mainly 256QAM, from a link-level perspective as a possible solution to this data explosion. 256 QAM in ideal channel conditions and high SINR range, achieves higher spectral efficiency compared to 64 QAM. However, due to transmitter and receiver impairments the gain of 256 QAM is questionable. we developed a physicallayer abstraction for the link-level performance of the 256QAM modulation order. Then, we evaluated the performance of 256 QAM in realistic environment including the impairments at the transmitter and receiver. These impairments can diminish the gains of 256 QAM depending on their magnitude.

No abstract

Introducing low-power Small Cells (SCs) in Heterogeneous Networks (HetNets) deployment can help in satisfying the increasing demands of mobile data rates. On/Off switching of SCs is one of the techniques introduced in LTEAdvanced to improve user throughput in HetNets via reducing interference. In this paper, we propose a novel traffic-aware user association technique which increases the throughput achieved by dynamic SC on/off switching by (12.7% to 24.7%) and reduces the energy consumed per bit by (41.1% to 60.7%) at different traffic loads. The proposed algorithm takes into consideration multiple factors including traffic load and dynamic on/off switching delays of SCs. The new technique also outperforms existing static on/off techniques at most traffic loads.

No abstract