Patent ID: 8994583
Filing Date: 2015-03-31
Classification: G01S

Abstract:
1. A method for determining at least one of a distance and a relative velocity by means of continuous wave radar measurements, comprising: generating a measurement signal in the form of a continuous wave radar signal; transmitting the measurement signal by means of an antenna; reflecting the measurement signal by means of a reflector, thereby providing a desired reflected measurement signal; receiving the desired reflected measurement signal; and determining at least one of a distance and a relative velocity between the antenna and the reflector by means of the desired reflected measurement signal, wherein said reflecting the measurement signal comprising asymmetrically modulating the measurement signal at the reflector, comprising applying a modulation signal which alternates between a first state and a second state, the first state having a first duration, and the second state having a second duration, the first duration differing from the second duration; said determining at least one of a distance and a relative velocity comprising identifying the desired reflected measurement signal, among several received reflections of the measurement signal, by means of the asymmetric modulation; and said determining at least one of a distance and a relative velocity comprising detecting and sampling the desired reflective measurement signal in a way that generates samples which generally follow two sinusoidal curves, one for each of said first and second states, determining which sinusoidal curve represents which state by means of the first and second durations, choosing one of the sinusoidal curves for the determination of at least one of a distance and a velocity, and using information from several consecutive periods of the sinusoidal curve and knowledge about which state it represents for that determination.