This paper introduces a hybrid receiver architecture for user equipment positioning by using UMTS and GNSS signals. After a review of the UMTS and Galileo/GPS signal structures and the state-of-the-art in receiver RF and base-band architectures, a configurable GNSS/UMTS architecture is proposed. The investigated concept is based on a reconfigurable receive chain to prevent duplication of hardware, which will result in considerably lower costs. The biggest challenge in the design of Galileo receivers are the extremely tight noise figure (NF) requirements. Another key issue of integrated GNSS/UMTS receivers is the maximum tolerable UMTS transmit leakage injected into the Galileo receiver.