Coded Modulation Simulation Framework for Time-of-Flight Cameras

Abstract

In recent years, application fields such as secure face recognition or autonomous driving increased the demand on efficient depth sensing systems. Time-of-Flight (ToF) sensors are well suited for these applications. The measurement principle is based on measuring the phase and consequently the delay of emitted and reflected light. For this delay measurement a continuous wave signal is emitted. Coded modulation replaces this continuous wave signal with code sequences. This enables new possibilities as the measurement range of the camera is adjustable with coded modulation. A well suited way for the characterization of this modulation method is a simulation framework. In this paper, we present a simulation framework for coded modulation ToF imagers. We present a detailed description of our PMD technology. From this theoretical description, we adapt an existing simulation model for coded modulation ToF cameras. The model of the camera considers various different noise sources. Furthermore depth calculation principles of coded modulation are introduced. As our evaluation shows, our framework is able to simulate real life behavior of coded modulation. Furthermore we are able to model the correlation form, and consequently the depth and intensity measurement behavior. In the end we evaluate our simulation results with real live measurement data. With this framework easy to use evaluation of coded modulation will enable new applications for this technique.