Abstract: A hybrid signal processing architecture characterized by all transmit and any receive is proposed firstly for distributed aperture coherent radar when receivers are co-located with partial transmitters. Then the closed-form Cramer-Rao Bounds (CRB) of coherence parameters estimation are derived under the condition that multiple pulses are transmitted, and the relationship among estimation performance and the number of antennas and pulses is studied. It is concluded that the CRB of parameters estimation for co-located antennas is slower than that for bistatic antennas, and the CRB reduces with the increase of the number of antennas and pulses. Finally, the numerical examples demonstrate the validity of the theoretical results.