Multicast Systems with Fair Scheduling in Non-identically Distributed Fading Channels

© 1967-2012 IEEE. Multicasting is emerging as an efficient method to deliver the same data to a group of users, thereby saving network resources. The fairness between different multicast groups is an important quality-of-service (QoS) indication, but it has not been given significant attention. In this paper, we propose a normalized signal-To-noise ratio (SNR)-based fair scheduling for multiple multicast groups in multicast systems. The system fairness and capacity are then analyzed and compared for both fair scheduling and greedy scheduling over independent but non-identically distributed (i.n.d.) fading channels. Closed-form expressions in terms of the system spectral efficiency, outage probability, system fairness, and average bit error rate (BER) are derived in an uncoded/coded M-Ary quadrature amplitude modulation based adaptive transmission multicast system over i.n.d. Rayleigh fading channels. Numerical results show that compared with greedy scheduling, fair scheduling achieves considerably high fairness at the cost of slight system capacity loss, regardless of the number of multicast groups. Our focus is on the physical layer without rate loss, but we also briefly discuss applications of the proposed scheduling in a cross-layer design subject to the loss rate QoS constraint

Performance assessment of wireless Two Way Relay Channel systems

The objective of this thesis is theoretical investigations and numerical simulations of Two Way Relay Channel (TWRC) systems, particularly in an impulsive noise environment. Special attention is given to investigation of a TWRC system based on polarized antennas. The first part of the thesis focuses on modelling of impulsive noise and the effect of impulsive noise on TWRC systems. The study was conducted by simulating the wireless TWRC models in the presence of impulsive noise. The bit error probability performance of the channel data was compared and at last their results are shown by graphs. The study has been further extended to multi antenna TWRC systems. Simulation analysis of multi antenna TWRC systems in an impulsive noise environment was conducted by using a MISO Alamouti scheme and a MIMO system. The second part of the thesis dedicated to investigation of TWRC polarization systems. A new TWRC scheme based on polarized antennas has been proposed and simulated. By polarization we are able to achieve higher spectral efficiency through the use of spatial multiplexing, and improve the reliability by spatial diversity. A new network topology based on TWRC polarization systems proposed. It is well suited to mitigate effect of delay in a communication system, particularly for high priority data transmission, or increase reliability of a communication system by redundant transmission

OrthoNoC: a broadcast-oriented dual-plane wireless network-on-chip architecture

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksOn-chip communication remains as a key research issue at the gates of the manycore era. In response to this, novel interconnect technologies have opened the door to new Network-on-Chip (NoC) solutions towards greater scalability and architectural flexibility. Particularly, wireless on-chip communication has garnered considerable attention due to its inherent broadcast capabilities, low latency, and system-level simplicity. This work presents ORTHONOC, a wired-wireless architecture that differs from existing proposals in that both network planes are decoupled and driven by traffic steering policies enforced at the network interfaces. With these and other design decisions, ORTHONOC seeks to emphasize the ordered broadcast advantage offered by the wireless technology. The performance and cost of ORTHONOC are first explored using synthetic traffic, showing substantial improvements with respect to other wired-wireless designs with a similar number of antennas. Then, the applicability of ORTHONOC in the multiprocessor scenario is demonstrated through the evaluation of a simple architecture that implements fast synchronization via ordered broadcast transmissions. Simulations reveal significant execution time speedups and communication energy savings for 64-threaded benchmarks, proving that the value of ORTHONOC goes beyond simply improving the performance of the on-chip interconnect.Peer ReviewedPostprint (author's final draft