Enhanced chaotic modulations for WPAN applications

Abstract

Chaotic signal has several advantages: aperiodic, difficult to predict, reconstructive, white wideband power spectra, and easy to generate. Due to above benefits, chaotic signal can be used in communication system. Slightly different starting condition can make infinite number of signal sets with very low correlation feature. Also, autocorrelation function can be made into an impulse-like signal that makes it hard to detect, it is robust in multipath fading, and anti-jamming. WPAN(Wireless Personal Area Networks) is a network that is made up with wireless connection between devices. IEEE 802.15 WPAN is a working group for a short distance wireless network. It can be divided into 4 Task Group(TG). TG4 is for sensor network which requires several months or years battery life, low complexity, and low data rate transmission properties. IEEE 802.15.4 technology is highlighted because of ubiquitous sensor networking. IEEE 802.15.4a is an alternative physical layer of IEEE 802.15.4. With properties of IEEE 802.15.4, IEEE 802.15.4a provides precise localization, ultra low power consumption, longer service area, low cost, and scalability of data rate. To satisfy those properties, IEEE 802.15.4a uses UWB(Ultra Wide Band) technology which is employed in IEEE 802.15.3a. IR(Impulse Radio), MB-OFDM(Multiband - Orthogonal Frequency Division Multiplex), Chirp signal, and Chaotic signal have UWB properties. Chaotic modulations, which are proposed in IEEE 802.15.4a standard, is divided into three different receiver types:coherent receiver, differential coherent receiver, and non-coherent receiver. CSK(Chaos Shift Keying)modulation requires coherent receiver. Implementation of CSK receiver is not easy since basis function cannot be regenerated at the receiver unless the receiver has the initial condition of the transmitter chaotic signal generator. Whereas, DCSK(Differential Chaos Shift Keying) is easier to embody basis function in that, it is restorable from the reference sig...