Telecommunications

Non-contiguous satellite channel allocation under cumulative interference: A hybrid price-and-branch approach

Categories Applications - OR and Management Sciences, Telecommunications Tags , , , ,

We study a non-contiguous channelisation problem arising in multi-beam geostationary satellite communications. Carriers have heterogeneous sub- channel demands and priorities; carriers within the same beam cannot share a subchannel, while reuse across beams is permitted subject to carrier- specific cumulative-interference budgets. Demand may be partially satis- fied, with a priority-weighted objective favouring higher-priority tra!c when … Read more

Cuts and semidefinite liftings for the complex cut polytope

Categories Polyhedra, Semi-definite Programming, Telecommunications Tags , , , , ,

We consider the complex cut polytope: the convex hull of Hermitian rank 1 matrices \(xx^{\mathrm{H}}\), where the elements of \(x \in \mathbb{C}^n\) are \(m\)th unit roots. These polytopes have applications in \({\text{MAX-3-CUT}}\), digital communication technology, angular synchronization and more generally, complex quadratic programming. For \({m=2}\), the complex cut polytope corresponds to the well-known cut polytope. … Read more

Trajectory Optimization of Unmanned Aerial Vehicles in the Electromagnetic Environment

Categories Control Applications, Nonlinear Optimization, Telecommunications

We consider a type of routing problems common in defence and security, in which we control a fleet of unmanned aerial vehicles (UAVs) that have to reach one or more target locations without being detected by an adversary. Detection can be carried out by a variety of sensors (radio receivers, cameras, personnel, etc) placed by … Read more

Joint MSE Constrained Hybrid Beamforming and Reconfigurable Intelligent Surface

Categories Constrained Nonlinear Optimization, Quadratic Programming, Telecommunications Tags , , ,

In this paper, the symbol detection mean squared error (MSE) constrained hybrid analog and digital beamforming is proposed in millimeter wave (mmWave) system, and the reconfigurable intelligent surface (RIS) is proposed to assist the mmWave system. The inner majorization-minimization (iMM) method is proposed to obtain analog transmitter, RIS and analog receivers, and the alternating direction … Read more

On optimally solving sub-tree scheduling for wireless sensor networks with partial coverage

Categories Branch and Cut Algorithms, Network Optimization, Telecommunications Tags , , , , ,

Energy efficiency and balancing are very important issues from the perspective of increasing the lifetime of a wireless sensor network (WSN). In this study, we concentrate on energy balancing. Given a WSN, we consider the problem to minimize its total power consumption over consecutive time slots with respect to communication activities. Disjoint subsets of nodes … Read more

QCQP with Extra Constant Modulus Constraints: Theory and Applications on QoS Constrained Hybrid Beamforming for mmWave MU-MIMO

Categories Constrained Nonlinear Optimization, Quadratic Programming, Telecommunications Tags , , , , , , , ,

The constant modulus constraint is widely used in analog beamforming, hybrid beamforming, intelligent reflecting surface design, and radar waveform design. The quadratically constrained quadratic programming (QCQP) problem is also widely used in signal processing. However, the QCQP with extra constant modulus constraints was not systematically studied in mathematic programming and signal processing. For example, the … Read more

MIMO Radar Optimization With Constant-Modulus and Any p-Norm Similarity Constraints

Categories Convex Optimization, Second-Order Cone Programming, Telecommunications Tags , , , , ,

MIMO radar plays a key role in autonomous driving, and the similarity waveform constraint is an important constraint for radar waveform design. However, the joint constant-modulus and similarity constraint is a difficult constraint. Only the special case with $\infty$-norm similarity and constant-modulus constraints is tackled by the semidefinite relaxation (SDR) and the successive quadratic refinement … Read more

Stochastic RWA and Lightpath Rerouting in WDM Networks

Categories Stochastic Programming, Telecommunications Tags , , ,

In a telecommunication network, Routing and Wavelength Assignment (RWA) is the problem of finding lightpaths for incoming connection requests. When facing a dynamic traffic, greedy assignment of lightpaths to incoming requests based on predefined deterministic policies leads to a fragmented network that cannot make use of its full capacity due to stranded bandwidth. At this … Read more

Optimal Steiner Trees Under Node and Edge Privacy Conflicts

Categories Branch and Cut Algorithms, Network Optimization, Telecommunications Tags , , , ,

In this work, we suggest concepts and solution methodologies for a series of strategic network design problems that find application in highly data-sensitive industries, such as, for instance, the high-tech, governmental, or military sector. Our focus is on the installation of widely used cost-efficient tree-structured communication infrastructure. As base model we use the well-known Steiner … Read more

Routing and Wavelength Assignment with Protection: A Quadratic Unconstrained Binary Optimization Approach

Categories 0-1 Programming, Quadratic Programming, Telecommunications

The routing and wavelength assignment with protection is an important problem in telecommunications. Given an optical network and incoming connection requests, a commonly studied variant of the problem aims to grant maximum number of requests by assigning lightpaths at minimum network resource usage level, while ensuring the provided services remain functional in case of a … Read more