Dynamic Spectrum Access Decisions

Preface

The coupling of spectrum sensing and dynamic spectrum access (DSA) solely with cognitive radios can do a disservice to the wireless communications community. Long before the concept of cognitive radios was coined, the defense community had elaborate spectrum sensing techniques. Since World War II, the defense community have had signal intelligence (SigInt) capabilities that are decades ahead of the commercial world's sensing capabilities. In today's commercial wireless system, we have the concept of finding the geolocation of a spectrum emitter through using multiple receivers (sensors) that can estimate the geolocation of the emitter and the direction of the emitter's beam. The defense community had this concept implemented in SigInt decades before the commercial world understood it and without having preknowledge of the emitted signal characteristics. SigInt capabilities used spectrum sensors extensively as part of the cat‐and‐mouse game of detecting the enemy's spectrum emission and overcoming the enemy's jammers.

As dynamic spectrum access capabilities are quickly evolving in the commercial wireless arena, one can see now how spectrum sensing leading to dynamic spectrum access ought to be decoupled from building the cognitive capabilities. As this book shows, we can have wireless communications systems that are not necessarily defined as cognitive systems, yet these systems can perform spectrum sensing, can analyze the sensed information and can use a form of dynamic ...