An ultrasound imaging system includes an array of ultrasound transducer elements chat send ultrasound energy into an object when energized for respective transmission time periods and provide responses to ultrasound energy emitted from the object for respective reception time periods, a reception modulation circuit modulating the responses with irregular sequences of modulation coefficients, a combiner circuit combining the modulated responses, and an image reconstruction processor configured to computer-process the combined modulated responses into one or more images of the object.