OPTIMAL PHASE KERNELS FOR TIME-FREQUENCY ANALYSIS Richard G. Baraniuk Department of Electrical and Computer Engineering Rice University Houston, TX 77005, USA L. Fridtjof Wisur-Olsen Nederlandse Aardolie Maatschappij B.V. Royal Dutch Shell Schoonebeek, The Netherlands Abstract: We consider the design of kernels for time-frequency distributions through the phase, rather than amplitude, response. While phase kernels do not attenuate troublesome cross-components, they can translate them in the time-frequency plane. In contrast to previous work on phase kernels that concentrated on placing the cross- components on top of the auto-components, we set up a ``don't care'' region and place the cross-components there. The close connections between optimal allpass kernels and optimal lowpass kernels provide new insight into signal-dependent time-frequency analysis.