  New generation of radar systems will need to coexist with other radio
frequency (RF) systems, anticipating their behavior and reacting appropriately
to avoid interference. In light of this requirement, this paper designs,
implements, and evaluates the performance of phase-only sequences (with
constant power) for intelligent spectrum utilization using the custom built
cognitive Multiple Input Multiple Output (MIMO) radar prototype. The proposed
transmit waveforms avoid the frequency bands occupied by narrowband interferers
or communication links, while simultaneously have a small cross-correlation
among each other to enable their separability at the MIMO radar receiver. The
performance of the optimized set of sequences obtained through solving a
non-convex bi-objective optimization problem, is compared with the
state-of-the-art counterparts, and its applicability is illustrated by the
developed prototype. A realistic Long Term Evolution (LTE) downlink is used for
the communications, and the real-time system implementation is validated and
evaluated through the throughput calculations for communications and the
detection performance measurement for the radar system.
