Remote Sensing with Constant-Modulus OFDM Signals from Complementary Sequences

Increasing commercial competition, desire for system redundancy, and convergence of technologies motivate the design of dual-function communications-radar (DFCR) systems. These individual systems perform both remote sensing and wireless communications through transmission of a singular waveform. Much of the literature examines use of orthogonal frequency-division multiplexing (OFDM) waveforms for this purpose, which suffer from high peak-to-average-power (PAPR) ratios, reducing the effectiveness of non-linear amplifiers. Herein, a technique for constructing constant-modulus (CM) OFDM signals from complementary sequences is exploited to perform DFCR operations. Advantages of this method of CM OFDM signal generation are discussed as well as trade-offs in attaining this desirable feature. Numerical simulations demonstrate differently constructed CM signals with processing gains within 7 dB of remote sensing using regular OFDM signals.