The tutorial “Introducing Information Metrics for Statistical Signal Processing,” [A1] provided the inspiration for our cover in this issue. In their “Lecture Notes” column, Steve Kay and Kaushallya Adhikari invite us to “a leisurely stroll through the garden of the beautiful information-theoretic flowers that have blossomed over the years.” This ends up being not only a pleasant stroll, but also an enriching one with useful insights into these measures and their interrelationships recounted with precision.

As wireless technology begins to utilize physically larger arrays and/or higher frequencies, the transmitter and receiver will reside in each other’s radiative near field. This fact gives rise to unusual propagation phenomena, such as spherical wavefronts and beam focusing, creating the impression that new spatial dimensions—called degrees of freedom (DOF)—can be exploited in the near field.

Multichannel signal processing technologies are moving toward the deployment of small and densely packed sensors yielding extremely large aperture arrays (ELAAs) in order to provide higher angular resolution and beamforming gain. In particular, technologies are moving beyond the fifth-generation (5G) networks, wherein the adoption of ELAAs or surfaces and the exploitation of higher-frequency bands, e.g., terahertz 

As we enter the new year, I would like to take a moment to reflect on our achievements from the past year and celebrate our successes. I am naming this “President’s Message” column the “State of the Society,” which will serve as a platform to share updates about our Society, including our activities, successes, and challenges.