Sample Approximation-Based Deflation Approaches for Chance SINR Constrained Joint Power and Admission Control

Consider the joint power and admission control (JPAC) problem for a multi-user single-input single-output (SISO) interference channel. Most existing works on JPAC assume the perfect instantaneous channel state information (CSI). In this paper, we consider the JPAC problem with the imperfect CSI, that is, we assume that only the channel distribution information (CDI) is available. We formulate the JPAC problem into a chance (probabilistic) constrained program, where each link's SINR outage probability is enforced to be less than or equal to a specified tolerance. To circumvent the computational difficulty of the chance SINR constraints, we propose to use the sample (scenario) approximation scheme to convert them into finitely many simple linear constraints. Furthermore, we reformulate the sample approximation of the chance SINR constrained JPAC problem as a composite group sparse minimization problem and then approximate it by a second-order cone program (SOCP). The solution of the SOCP approximation can be used to check the simultaneous supportability of all links in the network and to guide an iterative link removal procedure (the deflation approach). We exploit the special structure of the SOCP approximation and custom-design an efficient algorithm for solving it. Finally, we illustrate the effectiveness and efficiency of the proposed sample approximation-based deflation approaches by simulations.Comment: The paper has been accepted for publication in IEEE Transactions on Wireless Communication

Cross-layer design of multi-hop wireless networks

MULTI -hop wireless networks are usually defined as a collection of nodes equipped with radio transmitters, which not only have the capability to communicate each other in a multi-hop fashion, but also to route each others’ data packets. The distributed nature of such networks makes them suitable for a variety of applications where there are no assumed reliable central entities, or controllers, and may significantly improve the scalability issues of conventional single-hop wireless networks. This Ph.D. dissertation mainly investigates two aspects of the research issues related to the efficient multi-hop wireless networks design, namely: (a) network protocols and (b) network management, both in cross-layer design paradigms to ensure the notion of service quality, such as quality of service (QoS) in wireless mesh networks (WMNs) for backhaul applications and quality of information (QoI) in wireless sensor networks (WSNs) for sensing tasks. Throughout the presentation of this Ph.D. dissertation, different network settings are used as illustrative examples, however the proposed algorithms, methodologies, protocols, and models are not restricted in the considered networks, but rather have wide applicability. First, this dissertation proposes a cross-layer design framework integrating a distributed proportional-fair scheduler and a QoS routing algorithm, while using WMNs as an illustrative example. The proposed approach has significant performance gain compared with other network protocols. Second, this dissertation proposes a generic admission control methodology for any packet network, wired and wireless, by modeling the network as a black box, and using a generic mathematical 0. Abstract 3 function and Taylor expansion to capture the admission impact. Third, this dissertation further enhances the previous designs by proposing a negotiation process, to bridge the applications’ service quality demands and the resource management, while using WSNs as an illustrative example. This approach allows the negotiation among different service classes and WSN resource allocations to reach the optimal operational status. Finally, the guarantees of the service quality are extended to the environment of multiple, disconnected, mobile subnetworks, where the question of how to maintain communications using dynamically controlled, unmanned data ferries is investigated

Joint admission and association in vehicular networks

Abstract. To support vehicle to everything (V2X) communication which is an integral part of intelligent transportation systems (ITS), fifth generation (5G) communication systems will need to employ diverse range of technologies, which will ultimately lead to automated driving, improved traffic safety, improved traffic efficiency and infotainment.~V2X is considered as one of the most challenging applications of 5G, because it requires ultra reliable and low latency communication (URLLC) for safety critical applications and high data rates in many scenarios under mobility. Vehicles which can communicate with a base station or road side unit (RSU) are primary vehicles, which can act as relays to secondary vehicles which are out of coverage from the network. Therefore vehicle to infrastructure (V2I) and vehicle to vehicle (V2V) communication are employed to provide coverage for out of coverage vehicles. In this study joint problem of admission control for primary vehicles and user association for secondary vehicles in a singe cell downlink vehicular network is considered. The objective is to maximize the number of admitted primary vehicles, while associating all secondary vehicles. We consider the underlying communication system is based on millimeter wave communication at 60 GHz and we cast the optimization problem as an ℓ₀ minimization problem. This problem is known to be combinatorial and NP-hard. Hence, we propose a sub optimal, two stage algorithm to solve it. We compare the performance of proposed algorithm against the exhaustive search algorithm. From simulation results it can be observed, although the proposed algorithm is a sub optimal algorithm it gives optimal performance with improved efficiency. Hence, the proposed algorithm is able to determine the optimal association for vehicles which are out of coverage and optimal admission for vehicles which are in coverage