Transmitter Adaptation in Cognitive Radio Systems and Applications to Cognitive Radar

Abstract

The paper presents transmitter adaptation through interference avoidance (IA) for enabling more efficient use of the frequency spectrum in emerging cognitive radio (CR) systems. IA is introduced in a general signal space framework as a procedure that mitigates interference and improves the signal-to-interference+noise ratio (SINR) at the intended receiver by distributing the transmitted signal energy over signal dimensions with minimum interference. Application of IA for transmitter adaptation is illustrated in the context of spectral shaping for OFDM-based CR systems as well as SINR-based waveform design for cognitive radar for estimating the characteristics of multiple mutually interfering targets.