Exploiting Base Station for Remote Sensing: Modeling, Joint Transceiver Design, and Experiment

In this article, we investigate the orthogonal frequency-division multiplexing (OFDM) waveform design problem when utilizing the base station (BS) for sensing applications. The high autocorrelation sidelobe level (SLL) of the OFDM waveform and the hardware limitations at the BS that further exacerbate the SLL pose significant challenges in the detection of weak targets. To address this high SLL problem, two metrics are proposed as optimization criteria: the first metric is the peak sidelobe level (PSL) and the second is the modified merit factor (MMF), which refers to the ratio of the mainlobe to the weighted sum of sidelobes. Then, we formulate two optimization problems, namely minimizing the PSL and maximizing the MMF, while jointly designing the OFDM sequence and receive filter subject to practical hardware limitations of the BS in terms of spectra and peak-to-average power ratio. To tackle the resultant two nonconvex problems, two algorithms are proposed, which combine alternating optimization and split alternating direction method of multipliers judiciously. Numerical simulations verify that both methods outperform the state-of-the-art approaches and illustrate that our proposed design can achieve significantly low SLLs at around −50 dB. Furthermore, experimental results verify the effectiveness of the proposed methods.