Mr. Ammar Ahmad has successfully defended his Ph.D. dissertation, “Strategies for Radar-Communication Spectrum Sharing,” on February 15, 2021. Because of the COVID pandemic, the dissertation presentation was delivered virtually through Zoom.

Ammar’s dissertation focuses on spectrum sharing which has become increasingly important since the past decade due to the ongoing congestion of spectral resources. Higher data rates in wireless communications require expansion of existing frequency allocations. Significant research efforts have been made in the direction of cognitive radio to effectively manage the existing frequency usage. Recently, coexistence of multiple platforms within same frequency bands is considered effective to mitigate spectral congestion. The coexistence of radar and communication platforms in the same frequency bands requires both systems to work collaboratively to mitigate their mutual interference. This challenge can be significantly simplified if both systems are controlled by a joint control entity. Joint radar-communication (JRC) system is such an example where radar and communication system objectives are achieved by the same physical platform. In Ammar’s dissertation, three different types of JRC systems are investigated and novel signal processing techniques are developed to optimize their performance. These JRC systems respectively exploit a single transmit antenna, an antenna array for beamforming, and a distributed JRC network.

In addition to his work on spectrum sharing and JRC, Ammar has performed extensive work on over-the-horizon radar and sparse array signal processing that generated many publications. His work was supported in part by the Air Force Research Laboratory. Ammar received the Best Student Paper Award (Third Place) at the 2017 IEEE Radar Conference for his work on “Effective nested array design for fourth-order cumulant-based DOA estimation”. He is a coauthor of paper “DOA estimation exploiting interpolated multi-frequency sparse array” that received the Best Student Paper Award at the 2020 IEEE Sensor Array and Multichannel Signal Processing Workshop.

Ammar’s Ph.D. studies were supported by the Air Force Research Lab.

Please visit Ammar’s personal website for more information.