Robust transmit waveform and receive filter design in the presence of eclipsing loss and signal-dependent interference

Abstract

Eclipsing is the designation for the attendant loss that occurs for return echoes that arrive when the receiver is turned off during the transmission of a long pulse. Assuming unknown knowledge about the target echo delay (TED), this paper presents a robust design approach to jointly optimize the transmit sequence and receive filter for the detection of radar targets in the presence of return echo eclipsing loss and signal-dependent interference.The worst-case signal-to-interference-plus-noise-ratio (SINR) at the output of the filter is considered as the performance measure of the system. The robust design problem is formulated as a non-convex max-min optimization problem to robustify the system SINR with respect to the unknown target eclipsing loss condition. In addition to an energy constraint, an upper bound to the peak-to-average-power ratio (PAR) is imposed on the transmit sequence. The original non-convex optimization problem is solved using relaxation methods and an iterative optimization process alternating between two sequential semi-definite programming (SDP) problems. Then, the randomization methods are utilized to synthesize the transmit sequence and the corresponding filter sharing the robust response. Finally, the effectiveness of the proposed procedure is demonstrated through experimental results, underlining the performance enhancement offered by a robust joint design.