  In this paper, we focus on the design of the transmit waveforms of a
frequency diverse array (FDA) in order to improve the output
signal-to-interference-plus-noise ratio (SINR) in the presence of
signal-dependent mainlobe interference. Since the classical multi-carrier
matched filtering-based FDA receiver cannot effectively utilize the waveform
diversity of FDA, a novel FDA receiver framework based on multi-channel mixing
and low-pass filtering is developed to keep the separation of the transmit
waveform at the receiver side, while preserving the FDA range-controllable
degrees of freedom. Furthermore, a range-angle minimum variance distortionless
response beamforming technique is introduced to synthesize receiver filter
weights with the ability to suppress a possible signal-dependent mainlobe
interference. The resulting FDA transmit waveform design problem is initially
formulated as an optimization problem consisting of a non-convex objective
function and multiple non-convex constraints. To efficiently slove this, we
introduce two algorithms, one based on a signal relaxation technique, and the
other based on the majorization minimization technique. The preferable
performance of the proposed multi-channel low-pass filtering receiver and the
optimized transmit waveforms is illustrated using numerical simulations,
indicating that the resulting FDA system is not only able to effectively
suppress mainlobe interference, but also to yield estimates with a higher SINR
than the FDA system without waveform optimization.
