Channel Modeling for Phase-Based Ranging

This paper presents a Python-based simulation framework for the physical layer of Bluetooth Channel Sounding in accordance with Bluetooth Core Specification v6.2. The simulator implements Mode 3 phase-based ranging across 72 active tones in the 2.4 GHz ISM band and supports multiple propagation conditions, including free-space, static multipath, and IEEE 802.15.4a stochastic multipath channels. In addition, it models relevant hardware and interference effects such as phase noise, phase ramp, carrier frequency offset, IQ imbalance, ADC quantization, and narrowband interference from co-located Wi-Fi systems, with parameters derived from commercial SoC datasheets and field measurements. The framework enables controlled and repeatable analysis of physical layer effects that are difficult to isolate in over-the-air experiments and are not sufficiently represented in existing higher-level simulation tools. This work focuses exclusively on physical layer signal generation, channel modeling, and impairment injection, providing a foundation for future studies on Bluetooth Channel Sounding ranging and localization algorithms.