A Software-defined Radio Approach for Direction Finding

The increasing demand for wide bandwidth wireless communication in the context of a finite available frequency spectrum has led to an acute need for spectrum-efficient technologies. One solution is the Cognitive Radio approach, a device aware of the environment and able to modify its own parameters accordingly in order to optimize the performance. An important capability that leads to a higher spectrum-efficiency is the ability to accurately localize the target transceiver in order to “steer” its antenna directivity towards it. This paper proposes a practical implementation of a passive Software-Defined Radio localization system, suitable for integration in a Cognitive Radio device.