Adaptive filtering for FMCW interference mitigation in PMCW radar systems

A radar sensing system for a vehicle, the radar sensing system comprising:

• a transmitter configured for installation and use on a vehicle, and further configured to transmit radio signals;
• a receiver configured for installation and use on the vehicle, and further configured to receive radio signals that include the transmitted radio signals reflected from objects in the environment, as well as further including other radio signals transmitted from at least one other radar system;
• a processor;
• an adaptive filter;
• wherein the receiver is further configured to down-convert and sample the received radio signals to produce a sampled stream, and wherein the sampled stream is provided to the processor;
• wherein the processor is configured to control the adaptive filter, and responsive to the processor, the adaptive filter is configured to output a filtered sampled stream, such that the effect of radio signals transmitted from the at least one other radar system are removed from the sampled stream;
• and
• wherein the processor is further configured to measure an amplitude of the sampled stream and to measure an amplitude of the filtered sampled stream, and wherein the processor is further configured to select the filtered sampled stream for further range and velocity processing when a ratio of the amplitude of the filtered sampled stream to the amplitude of the sample stream is below a first threshold, otherwise the sampled stream is selected for the further range and velocity processing.

A method for removing interference from a radio signal received by a vehicle radar sensing system, said method comprising:

• providing a radar sensing system comprising a transmitter configured for installation and use on a vehicle and configured to transmit radio signals, and a receiver configured for installation and use on the vehicle and configured to receive radio signals that are the transmitted radio signals reflected from objects in the environment, and wherein the received radio signals further include other radio signals transmitted from at least one other radar system;
• providing an adaptive filter;
• down-converting and digitizing the received radio signals to produce a baseband sampled stream;
• providing the baseband sampled stream to the adaptive filter, wherein the adaptive filter is configured to output a filtered baseband sampled stream, such that the effect of the radio signals transmitted from the at least one other radar system are removed from the baseband sampled stream;
• measuring an amplitude of the baseband sampled stream and measuring an amplitude of the filtered baseband sampled stream;
• and
• selecting the filtered baseband sampled stream for further range and velocity processing when a ratio of the amplitude of the filtered baseband sampled stream to the amplitude of the baseband sampled stream is below a first threshold, otherwise, selecting the baseband sampled steam for the further range and velocity processing.