Abstract: A demodulator and a demodulating method for a WPAN are provided. In the demodulator for estimating a demodulation value of a received signal by correlating a PN code sequence of PN code having a periodic relationship for each code with a sample of the received signal, an IF processor unit separates the received signal to select only an imaginary part of the received signal, and digitalizes the selected imaginary part of the received signal. A differentiator unit delays the received signal outputted from the IF processor unit by preset delay time, and multiplies the delayed received signal by a current received signal to output a plurality of differentiated received signals. A conjugate unit sequentially stores samples of the imaginary parts of the differentiated received signals, and calculates correlation values by correcting the stored samples with PN coded sequences. A timing estimator unit receives the differentiated received signals and controls an operating timing of the conjugate unit.

Abstract: The present invention relates to a method for detecting interference and an interference detecting device for a wireless communication capable of improving detection accuracy of an interference signal in a wireless communication device without influencing network operation while the interference signal is detected; and, more particularly, to a method for detecting interference and an interference detecting device for a wireless communication to determine an interference signal by increasing an interference packet count according to an RSSI value, its own packet detection, gain reduction, deterioration of signal quality, the number of the same symbols, and so on and comparing an increased interference packet count value with a threshold value by using each ZigBee device as a main constituent of interference detection unlike a conventional method for detecting interference in which a ZigBee coordinator or a ZigBee router is a main constituent of interference detection.

Abstract: Provided is a low-power ZigBee device provided with a sleeping mode and an active mode including a power supplying unit for supplying a power; a Medium Access Control (MAC) processing unit for receiving a wake-up packet and for controlling a modem unit and an Radio Frequency (RF) unit; and a Central Processing Unit (CPU) for receiving and processing a data packet, wherein the MAC processing unit makes the power supplying unit apply a power to the CPU based on a result of checking an identification (ID) of the wake-up packet.

Abstract: The present invention relates to a multiple differential demodulator using a weighting value. The multiple differential demodulator according to the present invention includes a weighting value generator for integrating a real part and an imaginary part of a value acquired by multiplying one of a plurality of differentiated reception signals by a conjugated value of a differentiated PN code signal corresponding to a preset symbol, and determining the greater of the integrated real and integrated imaginary parts to apply a predetermined weighting value to the greater value, where the PN code signal is differentiated in the same fashion as the differentiated reception signals.

Abstract: The present invention relates to a method of estimating symbol synchronization for an Offset Quadrature Phase Shift Keying (OQPSK) demodulator applicable to a Zigbee receiver. More particularly, the invention relates to a method of recovering symbol synchronization of an OQPSK demodulator in which a reference correlation value is reset using a correlation value of a reception signal when detecting symbol synchronization in the OQPSK demodulator, preventing errors in detecting symbol synchronization due to noise, thereby increasing the accuracy in symbol synchronization.

Abstract: The invention relates to a symbol detector for detecting symbols received in a receive modem of short-range wireless personal area network of a ZigBee system (IEEE 802.15.4). An OQPSK short-range wireless communication system according to the invention acquires frequency offset in a received signal using a symbol contained in a preamble of a packet of the signal, multi-delay-differentiates the signal by a plurality of predetermined delay times, and complex-conjugates the acquired frequency offset to eliminate the frequency offset. Then, the OQPSK short-range wireless communication system according to the invention correlates the received signal with a PN sequence delay-differentiated through the same process to detect the symbols corresponding to the received signal.

Abstract: There is provided a receiver with a sigma-delta structure, the receiver including: a low noise amplifier amplifying a received signal according to a detection signal; a mixer converting an RF signal of the low noise amplifier into an IF signal; a sigma-delta A/D converter converting the IF signal from the mixer 200 into a digital signal; a 1 bit detector determining whether a voltage of the output signal of the mixer is greater than that of a predetermined reference voltage and outputting the detection signal including a result of the determination; and a demodulator obtaining an FFT result with respect to the signal from the sigma-delta A/D converter and adding or subtracting a predetermined gain value to or from the FFT result to calculate received signal strength indication (RSSI).

Abstract: A direct sequence spread spectrum (DSSS) transceiver including a DSSS transmitter and a DSSS receiver, wherein the DSSS transmitter includes: an integral code mapping unit mapping source bit data in one of 2N (N is a natural number) of predetermined symbols by N bits and mapping the symbol in one of integral code words that are obtained by previously integrating each of 2N of bi-orthogonal code words; and a radio frequency (RF) transmitting unit transmitting the integral code words mapped by the integral code mapping unit over an RF carrier wave, and the DSSS receiver includes: an RF receiving unit removing an RF carrier wave from an RF signal from the RF transmitting unit and converting an analog signal obtained by removing the RF carrier wave from the RF signal into a digital signal; a differential circuit unit differentiating and converting the digital signal from the RF receiving unit into bi-orthogonal code words; and a symbol detection unit detecting a symbol corresponding to a maximum value of correlat

Abstract: The invention relates to a receiver having a digital timing recovery function. The receiver of the invention detects frequency offset of a received signal by using symbol correlation between the received signal and a reference signal, and increases/decreases the number of data samples according to the detected frequency offset, thereby recovering symbol timing of the received signal.

Abstract: There is provided a dual mode WPAN transceiver including a dual mode WPAN transmitter and a dual mode WPAN receiver.

Abstract: Provided is an ultra low-power wake-up receiver capable of reducing an operating time of an analog receiver by controlling operation on/off of the analog receiver according to a clock signal from a digital receiver in an amplitude-shift keying (ASK) or on-off keying (OOK) radio receiver.

Abstract: Provided is a synchronization device for wireless communication packets, the synchronization device including an A/D (analog/digital) converter that converts an analog input signal applied from outside into a digital signal; a correlation calculating section that is connected to the A/D converter and correlates the converted input signal with a preset reference code so as to calculate a correlation value; a threshold setting section that is connected to the correlation calculating section and sets a threshold value of the correlation value; a maximum correlation detecting section that is connected to the correlation calculating section and the threshold setting section, compares the correlation value with the threshold value, detects the position of the maximum correlation value within each symbol of the input signal when the correlation value is larger than the threshold value, and judges whether a difference in position between the maximum correlation values of consecutive symbols is equal to the period of

Abstract: A timing estimator of an OQPSK demodulator is provided. In the timing estimator, an A/D converter converts an analog reception signal into a digital reception signal. A differential circuit section delays the digital reception signal from the A/D converter by a preset time and obtains a phase difference between a conjugate complex number signal of the delayed digital reception signal and the digital reception signal to offset a frequency error contained in the digital reception signal. A correlation operation section performs a correlation operation between a reference symbol differentiated in the same way as a differentiation of the differential circuit section and the reception signal to obtain each correlation value. A coherent detector detects a coherent point on the basis of the correlation value from the correlation operation section.

Abstract: The present invention relates to a method of estimating symbol synchronization for an Offset Quadrature Phase Shift Keying (OQPSK) demodulator applicable to a Zigbee receiver. More particularly, the invention relates to a method of recovering symbol synchronization of an OQPSK demodulator in which a reference correlation value is reset using a correlation value of a reception signal when detecting symbol synchronization in the OQPSK demodulator, preventing errors in detecting symbol synchronization due to noise, thereby increasing the accuracy in symbol synchronization.

Abstract: The invention relates to a symbol detector for detecting symbols received in a receive modem of short-range wireless personal area network of a ZigBee system (IEEE 802.15.4). An OQPSK short-range wireless communication system according to the invention acquires frequency offset in a received signal using a symbol contained in a preamble of a packet of the signal, multi-delay-differentiates the signal by a plurality of predetermined delay times, and complex-conjugates the acquired frequency offset to eliminate the frequency offset. Then, the OQPSK short-range wireless communication system according to the invention correlates the received signal with a PN sequence delay-differentiated through the same process to detect the symbols corresponding to the received signal.