A radar sensing system for a vehicle, the radar sensing system comprising: at least one transmitter configured for installation and use on a vehicle, and further configured to transmit a radio signal at one of a plurality of carrier frequencies; at least one receiver configured for installation and use on the vehicle, and further configured to receive a radio signal, wherein the received radio signal includes a reflected radio signal that is the transmitted radio signal reflected from an object; a processor configured to control the transmitter to selectively transmit radio signals on a selected one of the plurality of carrier frequencies, wherein the selected one of the plurality of carrier frequencies is selected from a subset of at least two or more carrier frequencies of the plurality of carrier frequencies; wherein the receiver is further operable to receive an interfering radio signal transmitted by a transmitter of another radar sensing system, and wherein the interfering radio signal interferes with the reflected radio signal; and wherein the processor is further configured to select at least one step of (i) select a carrier frequency with reduced interference and (ii) mitigate interference from the other radar sensing system; wherein, to mitigate interference, the transmitter is further configured to phase modulate the radio signal for transmission according to an aperiodic spreading code, and wherein the receiver is further configured to measure a noise floor of the received radio signal, and wherein, to further mitigate interference, the processor is further configured to switch the transmitter to a periodic spreading code when the noise floor increases above a threshold, and wherein the processor is further configured to select a period that is the same period selected by the another radar sensing system. at least one transmitter configured for installation and use on a vehicle, and further configured to transmit a radio signal at one of a plurality of carrier frequencies; at least one receiver configured for installation and use on the vehicle, and further configured to receive a radio signal, wherein the received radio signal includes a reflected radio signal that is the transmitted radio signal reflected from an object; a processor configured to control the transmitter to selectively transmit radio signals on a selected one of the plurality of carrier frequencies, wherein the selected one of the plurality of carrier frequencies is selected from a subset of at least two or more carrier frequencies of the plurality of carrier frequencies; wherein the receiver is further operable to receive an interfering radio signal transmitted by a transmitter of another radar sensing system, and wherein the interfering radio signal interferes with the reflected radio signal; and wherein the processor is further configured to select at least one step of (i) select a carrier frequency with reduced interference and (ii) mitigate interference from the other radar sensing system; wherein, to mitigate interference, the transmitter is further configured to phase modulate the radio signal for transmission according to an aperiodic spreading code, and wherein the receiver is further configured to measure a noise floor of the received radio signal, and wherein, to further mitigate interference, the processor is further configured to switch the transmitter to a periodic spreading code when the noise floor increases above a threshold, and wherein the processor is further configured to select a period that is the same period selected by the another radar sensing system.