Abstract: Methods and apparatuses for chaotic communication in a wireless personal area network, A chaotic information carrier is generated for a first predetermined frequency range using a ring-structure oscillator. The ring structure oscillator includes a non-linear element. Chaotic pulses are generated by modulating the chaotic information carrier for the first predetermined frequency range with a data signal. A shape of a spectral density envelope of the chaotic information carrier for the first predetermined frequency range is determined based on a set of parameters which include a first set of values.

Abstract: Spread spectrum transmission of information is performed using chaotic signals. Direct chaotic communication systems in which information is input to chaotic signal generated directly in information transmission frequency band, are achieved by forming broadband information carrier necessary for transmission and using a chaotic dynamic system whose structure is synthesized in advance in accordance with predetermined characteristics of broadband information carrier to cause chaotic dynamic system to provide operation of forming the broadband information carrier in form of a chaotic information carrier having prescribed spectral characteristics.

Abstract: A signal generator, a signal generation method, and a communication system using the same are provided. The signal generator includes a plurality of nonlinear elements which are connected in a ring; and a signal distributor which is arranged in the ring to form a closed loop, feeds part of a signal to one of the plurality of the nonlinear elements, and outputs signal generated by one of the plurality of nonlinear elements. The method includes arranging a plurality of nonlinear elements connected in a ring; inputting a signal to one of the nonlinear elements; amplifying the signal; receiving the amplified signal and generating a harmonic component of a frequency; clipping the signal; and feeding part of the signal back to one of the nonlinear elements and outputting a remainder of the signal. The system includes a chaotic signal generator; a signal distributor; a modulator; and a transmission circuit.

Abstract: Spread spectrum transmission of information is performed using chaotic signals. Direct chaotic communication systems in which information is input to chaotic signal generated directly in information transmission frequency band, are achieved by forming broadband information carrier necessary for transmission and using a chaotic dynamic system whose structure is synthesized in advance in accordance with predetermined characteristics of broadband information carrier to cause chaotic dynamic system to provide operation of forming the broadband information carrier in form of a chaotic information carrier having prescribed spectral characteristics.

Abstract: Provided is an apparatus and a method of measuring a distance between devices using a low clock frequency signal. The apparatus includes clock frequency generators, counters, a controller and a calculator for determining the distance based on clock signal overlap. Radio waves are transmitted and a number of clocks of a clock signal having a clock frequency b are counted, and if the transmitted radio waves are received again, a number of clocks of a clock signal having a clock frequency a are counted. If the clock signals having the clock frequencies a and b overlap with each other, counting of the numbers of the clocks of the clock signals having the frequencies b and a stops, and the distance is measured using the count values of the clock signals having the clock frequencies a and b. As a result, number of clocks of clock signals having low clock frequencies with a uniform difference can be counted to precisely measure a distance.

Abstract: A preamble generating method which includes computing (N) chaotic samples; transforming the (N) chaotic samples into (N) binary values of certain bits, respectively, and computing a chaotic sequence bit successively using the (N) binary values; and generating a preamble based on the chaotic sequence bit. By using the sequence bit from the chaotic samples, a plurality of preambles with optimum auto-correlation and cross-correlation properties is generated.

Abstract: A communication apparatus and a method for generating a signal thereof are provided. The communication apparatus adjusts a bandwidth or central frequency of an oscillating signal which is generated from a chaotic signal to be used in the modulation, or adjusts both the bandwidth and the central frequency. Accordingly, it is possible to transform the oscillating signal generated from the chaotic signal more diversely and thus to modulate an information signal more diversely and more adaptively.

Abstract: A radio frequency (RF) communication system having a chaotic signal generator and a method of generating a chaotic signal. The RF communication system includes a chaotic signal generator which generates a chaotic signal having a plurality of frequency components at a predetermined frequency band, a modulator which generates a chaotic carrier by combining the chaotic signal with a data signal which indicates information, and a transmission circuit which includes an antenna to transmit the chaotic carrier made at the modulator. The frequency signal generator comprises an oscillator which converts a DC bias power into a high frequency power, and a resonating unit which generates a wideband signal having a plurality of frequency components by passing a predetermined frequency band of the high frequency power signal.