Interference Avoidance in Wireless Systems

Motivated by the emergence of programmable radios, we seek to understand a class of communication system where pairs of transmitters and receivers can adapt their modulation/demodulation method in the presence of interference to achieve better performance. Using signal to interference ratio as a metric, we present a class of iterative distributed algorithms for synchronous systems which results in an ensemble of optimal waveforms for multiple users connected to a common receiver (or co-located independent receivers). That is, the waveform ensemble meets the Welch Bound with equality and therefore achieves minimum average interference over the ensemble of signature waveforms. We provide convergence proofs for a number of scenarios and propose further research to help develop a theory and practice of interference avoidance for future licensed and unlicensed band systems. i Rose, Ulukus and Yates: Interference Avoidance in Wireless Systems ii Contents 1 Introduction 1 2 Background 2 3 ..