This specification describes, in part, a technique for dynamic assignment of multiple antennas to different radio subsystems in a wireless device. The technique may include using an adaptive algorithm to allocate antennas to different radio subsystems as a function of, for example, application requirements, power requirements, and/or channel/network conditions. The specification also describes, in part, a technique for adaptively optimizing the use of the assigned antennas and other transmission parameters for each radio subsystem.