In this paper, we present a 2x-site test solution for GSM transceivers using only baseband signals for analysis. We perform all operations on standard-compliant GSM packets, thereby putting the device under the normal operating conditions. The transmitter on one device under test (DUT) is coupled with a receiver on another DUT to form a complete Tx-Rx path. Parameters of the two devices are decoupled from one another by carefully modeling the system into a known format and using signal processing techniques. Simulation as well as measurement results confirm the high accuracy of the proposed technique.