A vehicle radar system, such as a multiple input multiple output (MIMO) radar system, for estimating a Doppler frequency shift and a method of using the same. In one example, a modulated signal is mixed with an orthogonal code sequence and is transmitted by a transmit antenna array with a plurality of transmitting antennas. The signals reflect off of a target object and are received by a receive antenna array with a plurality of receiving antennas. Each of the received signals, which likely includes a Doppler frequency shift, is processed and mixed with a number of frequency shift hypotheses that are intended to offset the Doppler frequency shift and result in a series of correlation values. The frequency shift hypothesis with the highest correlation value is selected and used to correct for the Doppler frequency shift so that more accurate target object parameters, such as velocity, can be obtained.