Wireless Communication

About

Wireless communication remains an important communication method, in spite of having worse performance than wired channels due to interference, noise and distortion from damping, limited bandwidth, arriving time delays, and signal frequency variation (Doppler frequency shift). One of the main challenges is multipath propagation, caused by a series of unavoidable factors, including atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial objects such as mountains and buildings. The rising of chaotic signals in wireless communication in recent times responds to the expectation it can solve the performance issues and help provide better communication thanks to the intrinsic properties of chaos, such as sensitivity to initial conditions, broadband and orthogonality, and the fact that chaotic signals can be generated by low power, low cost, small area electronic circuits. Researchers from the University of Aberdeen and Xi’an Technology University have developed a wireless chaotic communication method that can send and receive information with broadband chaotic signals and avoid or reduce the transmission problems identified above.  The new communication protocol uses the perturbation on the initial condition of a chaotic mapping to encode the transmitted signal. The frequency of the encoded signal can be adjusted in a simple way so that the base band processing steps of traditional wireless communication (source and channel encoding and modulation) are replaced by a controlled perturbation in a much slower time scale than the transmission bit rate, thus saving energy and reducing cost. This protocol brings the advantages of robustness against filtering, noise, multipath and damping typical of wireless communication, together with a very simple and energy inexpensive pre-processing and decoding procedure.  The protocol is flexible and can be used in different environments. Subsea environments—where multipath is particularly critical—and satellite communication stand out as potential fields of application. IP Status UK priority patent and PCT application have been filed.