QoS-Aware Resource Allocation with Pilot-Aided Channel Estimation for Heterogeneous Wireless Networks.

The deployment of heterogeneous networks (HetNets) is a way to increase the network capacity and release part of the traffic generated by users inside a cell to small-scale wireless networks for service. In this context, the main problem is managing the interference due to the coexistence of small cells and macro cells. In this paper, a QoS-aware Resource Allocation (RA) algorithm jointly working with admission control (AC) over a two-tier HetNet scenario is investigated in the presence of both the pilot-symbols for channel estimation and the channel estimation error. The RA algorithm allows two users, the macro cell user (CU) and small cell user (SU), to simultaneously share the same resource block. Moreover, system performance and fairness are improved by including adaptive power allocation to users over resource blocks. In the framework of RA with proportional rate constraints, a novel algorithm is designed by including the effects of pilot-aided channel estimation. The algorithm is able to distribute the same proportional rate to all CUs and SUs, even in the presence of channel estimation error. Relevant numerical results for the downlink of a two-tier HetNet with pilot-aided channel estimation show that the rate dispersion is driven to zero while the sum-rate is maximized, and the average user rate penalty with respect to a perfect-CSI scenario may rise to 20%.

Design of reconfigurable on-chip wireless interconnections through Optical Phased Arrays.

In this paper we report the design of a device allowing on-chip optical wireless interconnections, based on transmitting and receiving Optical Phased Arrays (OPA). The proposed device aims at realizing high-bandwidth and power-efficient reconfigurable connections between multiple nodes, e.g. chiplets stacked onto a common silicon interposer in 2.5D manycore systems. The communication through an optical wireless switch is a completely novel approach to overcome the bottleneck of wired communication and to provide flexibility in the network topology configuration. We report the OPA design criteria as well as the results of three-dimensional Finite Difference Time Domain (FDTD) simulations. We exploit the in-plane radiation of simple taper antennas to implement 1×N and N × N switching matrices. The effect of the multipath propagation in the on-chip multi-layered medium is also taken into account.