In some implementations, the radar systems described herein utilize continuous-wave radar. In some implementations, the radar systems utilize un-modulated continuous wave radar to detect moving objects based on Doppler effects. In some implementations, the radar systems utilize frequency-modulated continuous wave radar (FMCW), such as sawtooth or sinusoidal frequency modulation, to determine object distances and motion. For example, in accordance with some implementations, the frequency is modulated across a frequency band, such as 3-10 GHz, 24-24.5 GHz, 57-64 GHz, and/or 77-81 GHz. In some implementations, the radar system utilizes FMCW and determines the velocity of various objects based on a phase shift, or a rate of phase shift, in radar signals reflected off the objects. In some implementations, the radar system utilizes a phase shifting modulation continuous wave radar (PMCW). In some implementations, the radar system utilizes PMCW to detect object locations and motion by generating pseudo-random phase-shifting sequences.