A DSM-PPM-Based Integrated Sensing and Communication Architecture for LEO Satellite Networks

This study proposes a DSM-PPM-based ISAC architecture for 6G LEO satellite networks, addressing waveform design challenges in high-mobility scenarios. By integrating Delta-Sigma modulation with pulse position modulation, the system converts QAM signals to low-PAPR OOK waveforms with 100 MHz bandwidth, achieving 32 dB in-band SNR improvement through noise shaping. Simulations under 3GPP NTN standards demonstrate dual functionality: 1 Gbit/s communication throughput (BER <1×10⁻<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup>) and 15 cm sensing resolution via pulse compression, with >95% target detection accuracy under Sea State 3. The design resolves noise-complexity trade-offs in quantization, enables dynamic spectrum optimization, and establishes a standardized evaluation framework for space-air-ground ISAC systems, advancing LEO constellations toward integrated 6G services.