Radar Waveform Optimization for Joint Radar Communications Performance

We develop and present a radar waveform design method that optimizes the spectral shape of the radar waveform so that joint performance of a cooperative radar-communications system is maximized. The continuous water-filling (WF) spectralmask shaping method presented in this paper is based the previously derived spectral-mask shaping technique. However, the method presented in this paper … Read more

Novel Radar Waveform Optimization for a Cooperative Radar-Communications System

We develop and present the novel minimum estimation error variance waveform design method, that optimizes the spectral shape of a unimodular radar waveform such that the performance of a joint radar-communications system that shares spectrum is maximized. We also perform a numerical study to compare the performance of the new technique with the previously derived … Read more

Combinatorial Optimization Problems in Engineering Applications

This paper deals with several combinatorial optimization problems. The most challenging such problem is the quadratic assignment problem. It is considered in both two dimensions (QAP) and in three dimensions (Q3AP) and in the context of communication engineering. Semidefinite relaxations are used to derive lower bounds for the optimum while heuristics are applied to either … Read more

Generation techniques for linear and integer programming instances with controllable properties

This paper addresses the problem of generating synthetic test cases for experimentation in linear programming. We propose a method which maps instance generation and instance space search to an alternative encoded space. This allows us to develop a generator for feasible bounded linear programming instances with controllable properties. We show that this method is capable … Read more

Polynomial-Time Methods to Solve Unimodular Quadratic Programs With Performance Guarantees

We develop polynomial-time heuristic methods to solve unimodular quadratic programs (UQPs) approximately, which are known to be NP-hard. In the UQP framework, we maximize a quadratic function of a vector of complex variables with unit modulus. Several problems in active sensing and wireless communication applications boil down to UQP. With this motivation, we present three … Read more

QPLIB: A Library of Quadratic Programming Instances

This paper describes a new instance library for Quadratic Programming (QP), i.e., the family of continuous and (mixed)-integer optimization problems where the objective function, the constrains, or both are quadratic. QP is a very “varied” class of problems, comprising sub-classes of problems ranging from trivial to undecidable. Solution methods for QP are very diverse, ranging … Read more

Mixed-Integer Nonlinear Programming Formulation of a UAV Path Optimization Problem

We present a mixed-integer nonlinear programming (MINLP) formulation of a UAV path optimization problem in an attempt to find the globally optimum solution. As objective functions in UAV path optimization problems typically tend to be non-convex, traditional optimization solvers (typically local solvers) are prone to local optima, which lead to severely sub-optimal controls. For the … Read more

HEURISTIC ALGORITHMS FOR DESIGNING UNIMODULAR CODE SEQUENCES WITH PERFORMANCE GUARANTEES

In this study, we develop heuristic methods to solve unimodular quadratic programming (UQP) approximately, which is known to be NP-hard. UQP-type problems appear naturally in radar waveform design and active sensing applications. In the UQP framework, we optimize a sequence of complex variables with unit modulus by maximizing a quadratic function. To solve the UQP … Read more

Achievable Rates for a LAN-Limited Distributed Receiver in Gaussian Interference

A base node seeks to receive a broadcast with its own observation in addition to side-information provided via a local area network (LAN) from several ‘helper nodes,’potentially occluded by an external interferer. Ideally, helpers would convey their precise observations to the base but the LAN has limited capacity, so helpers must compress and forward. Bounds … Read more

Modulation Design for MIMO-CoMP HARQ

Modulation diversity (MoDiv) is a simple and practical transmission enhancement technique that utilizes different modulation mappings to reduce packet loss rate and achieve higher link throughput. MoDiv is particularly meaningful and effective in hybrid-ARQ (HARQ) systems. We study the deployment and optimization of MoDiv for HARQ in a MIMOcoordinated multi-point (MIMO-CoMP) scenario under Rician fading … Read more