Interference avoidance system for vehicular radar system

An interference avoidance system for detecting and avoiding interference in a vehicular target detection system including:

• a) transmit means for transmitting at least one signal;
• b) receive means for receiving at least one signal;
• c) comparison means, coupled to the transmit means and the receive means, for comparing the transmitted signal with the received signal and generating a difference signal based upon the comparison;
• d) sampling means, coupled to the comparison means, for sampling and digitizing the difference signal;
• e) data storage means, coupled to the sampling means, for storing the digitized samples of the difference signal;
• counter means, coupled to the sampling means, for determining whether at least 1,024 new samples have been stored in the data storage means;
• g) mapping means, coupled to the data storage means, for mapping the difference signal from the time domain into the frequency domain using the last 1,024 new samples stored in the data storage means;
• h) interference detection means, coupled to the mapping means, for determining from the frequency domain representation of the last 1,024 new samples stored in the data storage means whether the power present in at least one selected frequency band is greater than at least one threshold value;
• i) flushing means, coupled to the mapping means and the interference detection means, for flushing the samples stored in the data storage means upon detection of interference;
• j) frequency control means, coupled to the interference detection means and the transmit means, for changing the frequency of the signal being transmitted;
• k) counter means, coupled to the sampling means, for determining whether at least 2,048 samples have been stored in the data storage means;
• l) mapping means, coupled to the data storage means, for mapping the difference signal from the time domain into the frequency domain using the last 2,048 samples stored in the data storage means;
• m) interference detection means, coupled to the mapping means, for determining from the frequency domain representation of the last 2,048 samples stored in the data storage means whether the power present in at least one selected frequency band is greater than at least one threshold value;
• n) counter means, coupled to the sampling means, for determining whether at least 4,096 samples have been stored in the data storage means;
• o) mapping means, coupled to the data storage means, for mapping the difference signal from the time domain into the frequency domain using the last 4,096 samples stored in the data storage means;
• p) interference detection means, coupled to the mapping means, for determining from the frequency domain representation of the last 4,096 samples stored in the data storage means whether the power present in at least one selected frequency band is greater than at least one threshold value.

An method for detecting and avoiding interference in a vehicular target detection system including the steps of:

• a) transmitting at least one signal;
• b) receiving at least one signal;
• c) comparing the transmitted signals with the received signals and generating a difference signal based upon the comparison;
• d) sampling and digitizing the difference signal;
• e) storing the digitized samples of the difference signal in a data storage device;
• f) determining whether at least 1,024 new samples have been stored in the data storage device;
• g) repeating steps a) through f) until at least 1,024 new samples have been stored in the data storage device;
• h) mapping the difference signal from the time domain into the frequency domain using the last 1,024 new samples stored in the data storage device;
• i) determining from the frequency domain representation of the last 1,024 new samples stored in the data storage device whether the power present in at least one selected frequency band is greater than at least one threshold value, and if so, then flushing the samples stored in the data storage device, changing the frequencies of the signals being transmitted, and returning to step a);
• otherwise
• j) determining whether at least 2,048 samples have been stored in the data storage device;
• k) repeating steps a) through k) until 2,048 samples have been stored in the data storage device;
• l) mapping the difference signal from the time domain into the frequency domain using the last 2,048 samples stored in the data storage device;
• m) determining from the frequency domain representation of the last 2,048 samples stored in the data storage device whether the power present in at least one selected frequency band is greater than at least one threshold value, and if so, then flushing the samples stored in the data storage device, changing the frequencies of the signals being transmitted, and returning to step a);
• otherwise
• n) determining whether at least 4,096 samples have been stored in the data storage device;
• o) repeating steps a) through e), followed by steps l) through o) until 4,096 samples have been stored in the data storage device;
• p) mapping the difference signal from the time domain into the frequency domain using the last 4,096 samples stored in the data storage device;
• q) determining from the frequency domain representation of the last 4,096 samples stored in the data storage device whether the power present in at least one selected frequency band is greater than at least one threshold value, and if so, then flushing the samples stored in the data storage device, changing the frequencies of the signals being transmitted, and returning to step a);
• otherwise
• r) repeating steps a) through e), followed by steps p) through r).

An interference avoidance system for detecting and avoiding interference in a vehicular target detection system including:

• a) a transmitter for transmitting at least one signal;
• b) a receiver for receiving at least one signal;
• c) a comparator, coupled to the transmitter and the receiver, for comparing the transmitted signal with the received signal and generating a difference signal based upon the comparison;
• d) a sampling circuit, coupled to the comparator, for sampling and digitizing the difference signal;
• e) a data storage device, coupled to the sampling circuit, for storing the digitized samples of the difference signal;
• f) a counter, coupled to the sampling circuit, for determining the number of samples stored in the data storage device and representing that number as a count value;
• g) a mapping circuit, coupled to the data storage device, for mapping the difference signal from the time domain into the frequency domain using a selected number of the most recent new samples stored in the data storage device;
• h) an interference detection system, coupled to the mapping circuit, for determining from the frequency domain representation of the selected most recently sampled new samples stored in the data storage means whether the power present in at least one selected frequency band is greater than at least one threshold value;
• i) a flusher, coupled to the mapping circuit and the interference detection system, for flushing the samples stored in the data storage means upon detection of interference and for resetting the counter;
• j) a frequency controller, coupled to the interference detection system and the transmitter, for changing the frequency of the signal being transmitted.