Phased-array ultrasound imaging employing multiple receive beamforming with coded excitation is investigated. The approach is based on simultaneous excitation of transducer array elements with coded signals, and multiple receive beamforming. It involves only a single transmit-receive step for reconstruction of each image frame. The excitation signals are chosen as decorrelated binary pseudo-noise sequences. Performance of the coded excitation imaging is tested through simulations for code sequences with various lengths and different decoding filters. The simulation results show that the ultrasound scanner with the coded excitation can produce up to -15 dB side lobe level at the transmit beam profile with sufficiently long codes, whereas very short codes result in about -7 dB side lobe level. The coded excitation imaging improves the signal-to-noise ratio and minimizes the signal firings, and hence provides increased penetration depth and frame rates. (C) 1997 Elsevier Science B.V.