Abstract: There is provided a node position measurement apparatus and method including sequentially transmitting measurement impulses corresponding to a plurality of base stations, respectively, to at least one node; receiving time offset information that is a difference in time of receiving the measurement impulses, from the node receiving the measurement impulses; and measuring a position of the node based on the time offset information.

Abstract: An azimuth measurement apparatus including: a positioning signal receiver receiving a first impulse positioning signal and a second impulse positioning signal from a first fixed position and a second fixed position, respectively; a phase difference detector detecting a phase difference between the first impulse positioning signal and the second impulse positioning signal; and an azimuth calculator measuring an azimuth of an object of positioning, based on the detected phase difference of the two positioning signals.

Abstract: A position recognition method and system include transmitting a first transmit signal and a second transmit signal via a first transmit antenna and a second transmit antenna of a transmitter at intervals; receiving the first transmit signal and the second transmit signal via an receive antenna of a receiver; and calculating a position of the receiver using transmission times of the first transmit signal and the second transmit signal. Accordingly, the mobile object can recognize its position efficiently.

Abstract: A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.

Abstract: An apparatus and method for generating an intermediate frequency (IF) to be transferred to a single sideband (SSB) generator which generates carriers using one local oscillator (LO) signal and at least two IF signals that are received. A group signal is generated which includes a non-phase-shifted signal and a phase-shifted signal to a predetermined value with respect to each IF. One of the group signals is selected and transferred to the SSB generator. Accordingly, the SSB generator performs the phase shift on the LO signal alone.

Abstract: An ultra wideband network transmitter and receiver, and a method capable of switching to a high-speed mode or a low-speed mode are provided. The transmitter includes a multi-band orthogonal frequency division multiplexing (MB-OFDM) modem; a direct sequence code division multiple access (DS-CDMA) modem; a mode switch which switches to the MB-OFDM modem or the DS-CDMA modem according to a mode control signal; a phase lock loop (PLL) which locks a frequency used for MB-OFDM type modulation or the DS-CDMA type modulation; and a central processing unit (CPU) controls the PLL and mode switch. The receiver includes an MB-OFDM modem; an DS-CDMA modem; an automatic gain controller; an analog-to-digital converter; an PLL; a mode switch; and an CPU. The method includes receiving a command to transmit data; and switching to an MB-OFDM modem to select to a high-speed operation mode.

Abstract: A DC offset correction apparatus and method of a receiver in a multiband-hopping communication system is provided. The DC offset correction apparatus of the receiver in the communication system which hops to a plurality of bands, includes a controller for generating and outputting a plurality of DC offset correction signals different from each other for the respective bands; a plurality of digital-to-analog converters (DACs) for receiving, digital-to-analog converting and outputting the plurality of the DC offset correction signals from the controller; an analog multiplexer (MUX) for switching to output one of the plurality of the DC offset correction signals output from the plurality of the DACs, respectively; and an adder for adding and outputting an input signal with the output signal of the analog MUX. Accordingly, the DC offset correction apparatus can be implemented by low-speed DACs and the fast analog MUX that are relatively small-sized and low-cost elements.

Abstract: A frequency generation apparatus and a method are provided. The frequency generation apparatus for generating a plurality of center frequencies for use in multi-band hopping communication, includes: an oscillator generating an oscillation frequency; a reference frequency generator multiplying the oscillation frequency by a first multiplication rate to generate a reference frequency; a compensation frequency generator multiplying the oscillation frequency by a second multiplication rate to generate a compensation frequency for compensating for the influence of a frequency offset of the oscillation frequency; and a center frequency generator generating the plurality of center frequencies using the reference frequency and the compensation frequency. Therefore, by compensating for the influence of a frequency offset of an oscillation frequency on the generation of center frequencies, it is possible to generate stable center frequencies.

Abstract: A DC offset correction apparatus and method of a receiver in a multiband-hopping communication system is provided. The DC offset correction apparatus of the receiver in the communication system which hops to a plurality of bands, includes a controller for generating and outputting a plurality of DC offset correction signals different from each other for the respective bands; a plurality of digital-to-analog converters (DACs) for receiving, digital-to-analog converting and outputting the plurality of the DC offset correction signals from the controller; an analog multiplexer (MUX) for switching to output one of the plurality of the DC offset correction signals output from the plurality of the DACs, respectively; and an adder for adding and outputting an input signal with the output signal of the analog MUX. Accordingly, the DC offset correction apparatus can be implemented by low-speed DACs and the fast analog MUX that are relatively small-sized and low-cost elements.

Abstract: A reference frequency generation method and apparatus for communication systems that transmit and receive data by use of an ultra wide band of at least two frequency groups having at least two reference frequencies. The method and apparatus generate the reference frequencies by generating generation frequencies by use of a frequency generated from the local oscillator, and generating adjustment frequencies for adjusting the generation frequency. One generation frequency and one adjustment frequency are selected from the generation frequencies and adjustment frequencies, and the reference frequencies are generated by use of the selected generation frequency and adjustment frequency.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.

Abstract: A signal reception apparatus and method for communication systems. The signal reception apparatus for communication systems according to the present invention is applicable to communication environments in which a plurality of sub-bands having different frequency bands are sequentially used for communications. An embodiment of the invention has a multi-band index generation unit, a multi-band frequency generation unit, a multiplication unit, a correlation signal reception unit, and a buffer unit. The multi-band index generation unit generates a multi-band index corresponding to a sub-band to which a received signal is transmitted in correspondence with the multi-band index. The multiplication unit outputs a signal obtained by multiplying the received signal by the multi-band frequency. The correlation signal reception unit integrates and outputs the signal of the multiplication unit based on an integral time set in correspondence with the multi-band index.

Abstract: An apparatus and method for generating an intermediate frequency (IF) to be transferred to a single sideband (SSB) generator which generates carriers using one local oscillator (LO) signal and at least two IF signals that are received. A group signal is generated which includes a non-phase-shifted signal and a phase-shifted signal to a predetermined value with respect to each IF. One of the group signals is selected and transferred to the SSB generator. Accordingly, the SSB generator performs the phase shift on the LO signal alone.

Abstract: A method for reference signal generating in an ultra wideband (UWB) communication system which sends out and receives data by using at least two reference signals of predetermined frequencies. A first signal group, which comprises a local oscillation (LO) signal and a signal at a predetermined phase difference with respect to the LO signal, is generated. One among at least two intermediate frequency (IF) signals is selected for the adjustment of the frequency of the LO signals, and a second signal group, which comprises the selected IF signal and a signal at a predetermined phase difference with respect to the selected IF signal, is generated. Two mixed signals are generated from the first and the second signal groups, the mixed signals being mixed without overlap, and a reference signal is generated by adding the two generated signals.

Abstract: An ultra wideband (UWB) wireless transmitter includes a first pulse generator for modulating data to be transmitted and outputting a first linear modulated signal, a second pulse generator for modulating the data to be transmitted and outputting a second linear modulated signal, an adder for adding the first and the second linear modulated signals, a pulse shaper for shaping the signal output from the adder, a carrier generator for outputting a carrier, a mixer for mixing the signal output from the pulse shaper with the carrier, a transmission unit for transmitting the signal output from the mixer, and a controller for controlling the modulation of the signal to be transmitted by controlling the operation of the first and the second pulse generators and the carrier generator. As a result, a data transmission rate can be greatly increased without having any inter-pulse interference even when the pulse intervals are reduced.

Abstract: Disclosed is a noncoherent pulse position and phase shift keying (PPPSK) transmission/reception system and a transmission/reception signal processing method therefor. Transmission system has an information generation unit for generating information data; a modulation unit for deciding a phase and a timing position corresponding to generated information data; and a wavelet generation unit for generating a wavelet based on the decided phase and timing position, and the reception system has an offset unit for mixing the reception signal with a high-frequency component corresponding to a center frequency of a transmission frequency band and offsetting a high frequency of the reception signal; a demodulation unit for generating at least one reference signal based on a previous signal precedingly received with respect to the reception signal and mixing the reference signals and the reception signal; and a decision unit for deciding information data corresponding to the reception signal based on mixing results.