Asymptotic buffer overflow probabilities in multiclass multiplexers : part II : the GLQF policy

Cover title.Includes bibliographical references (p. 33-35).Supported by a Presidential Young Investigator Award. DDM-9158118 Matching funds from Draper Laboratory. Supported by ARO. DAAL-03-92-G-0115Dimitris Bertsimas, Ioannis Ch. Paschalidis, John N. Tsitsiklis

Asymptotic buffer overflow probabilities in multiclass multiplexers : part I : the GPS policy

Cover title.Includes bibliographical references (p. 34-37).Supported by a Presidential Young Investigators award. DDM-9158118 Matching funds from Draper Laboratory. Supported by ARO. DAAL-03-92-G-0115Dimitris Bertsimas, Ioannis Ch. Paschalidis, John N. Tsitsiklis

Opportunistic packet scheduling in cellular networks with base station antenna arrays

We study the issue of designing a downlink scheduling policy for a cellular network with base station antenna arrays. We derive an optimal scheduling policy that achieves the throughput region, which is a set of feasible arrival rate vectors that can be stabilized by some scheduling policy. Then, based on the structure of the derived optimal policy whose complexity increases exponentially with the number of users in the system, we propose two heuristic scheduling algorithms with much lower complexity. We demonstrate that our proposed algorithms perform much better than other heuristic algorithms that do not take into consideration the physical layer constraints and/or queue lengths in the sense that they have a larger throughput region than other heuristic algorithms

CROSS-LAYER RESOURCE ALLOCATION ALGORITHMS IN WIRELESS NETWORKS WITH ANTENNA ARRAYS

The application of antenna array is a promising approach to improving the capacity of a wireless network. In this dissertation, we study the application of antenna arrays at the base stations (BSs) in a wireless cellular network. We focus on the downlink transmission. This application requires the BSs be aware of the locations and channel conditions of the mobile users. Towards this end, we propose a family of MAC layer protocols that enable a base station to learn the locations and channel conditions of a number of intended users. Our simulation results demonstrate that the inter-cell interference significantly degrades the system performance of the previously proposed beamforming algorithms in terms of packet loss probability (PLP) in a multi-cell environment. To cope with inter-cell interference, we propose beamforming algorithms that achieve target PLP in the presence of random inter-cell interference. The application of antenna array on the physical layer has great impact on the protocols of higher layers. Novel MAC algorithms and protocols need to be designed to take advantage of the capacity enhancement provided by antenna array on the physical layer. In this dissertation, the issue of designing a downlink scheduling policy with base station antenna arrays is studied. We derive an optimal scheduling policy that achieves the throughput region. Then, based on the structure of the derived optimal policy, we propose two heuristic scheduling algorithms. The interference experienced by each node in an ad-hoc network exhibits stochastic nature similar to the inter-cell interference in a cellular network. We propose a power control algorithm in a distributed scheme to achieve target PLP. Furthermore, the proposed power control algorithm is shown to minimize the aggregate transmission power given the PLP constraint. In the above problems, we mainly consider the non-real-time traffic where throughput is the QoS parameter of concern. On the other hand, delay is an important QoS parameter for real time traffic. In this dissertation, we also consider the scheduling of real time packets by a BS with awareness of physical layer channel conditions of different users

Large deviations in high speed communication networks

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 215-221).by Ioannis Ch. Paschalidis.Ph.D