This paper presents the development and evaluation of WiThRay, a new wireless three-dimensional ray-tracing (RT) simulator. RT-based simulators are widely used for generating realistic channel data by combining RT methodology to get signal trajectories and electromagnetic (EM) equations, resulting in generalized channel impulse responses (CIRs). This paper first provides a comprehensive comparison on methodologies of existing RT-based simulators. We then introduce WiThRay, which can evaluate the performance of various wireless communication techniques such as channel estimation/tracking, beamforming, and localization in realistic EM wave propagation. WiThRay implements its own RT methodology, the bypassing on edge (BE) algorithm, that follows the Fermat's principle and has low computational complexity. The scattering ray calibration in WiThRay also provides a precise solution in the analysis of EM propagation. Different from most of the previous RT-based simulators, WiThRay incorporates reconfigurable intelligent surfaces (RIS), which will be a key component of future wireless communications. We thoroughly show that the channel data from WiThRay match sufficiently well with the fundamental theory of wireless channels. The virtue of WiThRay lies in its feature of not making any assumption about the channel, like being slow/fast fading or frequency selective. A realistic wireless environment, which can be conveniently simulated via WiThRay, naturally defines the physical properties of the wireless channels. WiThRay is open to the public, and anyone can exploit this versatile simulator to develop and test their communications and signal processing techniques.

翻译：本文介绍了WiThRay——一种新型无线三维射线追踪（RT）仿真器的开发与评估。基于RT的仿真器通过结合射线追踪方法获取信号轨迹与电磁（EM）方程，生成通用信道脉冲响应（CIRs），被广泛用于生成逼真的信道数据。本文首先对现有基于RT的仿真器方法进行了全面比较，随后介绍了WiThRay。该仿真器能够在真实电磁波传播场景中评估多种无线通信技术的性能，如信道估计/跟踪、波束赋形与定位。WiThRay实现了其专有的射线追踪方法——边缘绕行（BE）算法，该算法遵循费马原理且计算复杂度低。此外，WiThRay中的散射射线校准为电磁传播分析提供了精确解决方案。与大多数现有基于RT的仿真器不同，WiThRay集成了可重构智能表面（RIS），这将是未来无线通信的关键组成部分。我们充分证明，WiThRay生成的信道数据与无线信道基本理论高度吻合。WiThRay的优势在于不预设任何信道假设（如慢/快衰落或频率选择性），通过便捷模拟真实无线环境，自然定义无线信道的物理特性。WiThRay已向公众开放，用户可利用这一多功能仿真器开发与测试其通信及信号处理技术。