Low PAPR OFDM Using SLM with Modified Riemann Matrix in JARC Systems

Orthogonal Frequency Division Multiplexing (OFDM) is a promising technology for joint automotive radar and communication (JARC) systems operating in the 77–81 GHz band. While the Selective Mapping (SLM) technique effectively reduces the Peak-to-Average Power Ratio (PAPR) through phase sequence selection, this process traditionally requires significant computational resources, which can decrease data transmission rates. This paper introduces a novel approach that leverages a modified Riemann matrix to reduce PAPR with minimal increase in computational complexity within an OFDM radar framework. We analyze range-velocity profiles under various SNR conditions in an AWGN (Additive White Gaussian Noise) channel. The proposed method not only achieves a substantial 92.1% reduction in PAPR compared to conventional OFDM but also simplifies the computational process to mere elementwise multiplication, ensuring high fidelity in radar range-velocity estimation.