Abrégé

The present invention relates to an apparatus and method for controlling a wake-up point of a wireless terminal device, the apparatus designed to reduce timing errors when the device wakes up, by compensating a frequency change of an RTC due to a change in temperature during a sleep period. The apparatus and method for controlling a wake-up point of a wireless communication device according to the present invention: have the effect of synchronizing with a network by performing a simple re-synchronization procedure by reducing errors in the system time and frame boundary after waking up, by compensating a frequency change of an RTC due to a change in temperature during a sleep period; and have the advantage of reducing the component unit cost for manufacturing the product, since the apparatus does not require an expensive temperature compensated crystal oscillator (TCXO).

Classes IPC  ?

• H04W 56/00 - Dispositions de synchronisation
• H04W 52/02 - Dispositions d'économie de puissance

Abrégé

The present invention relates to an earth leakage circuit breaker usable as an arc-fault circuit interrupter, and is to: install an arc detection module for detecting an arc and generating a digital signal, at one side of the earth leakage circuit breaker; provide the digital signal to a zero-phase current transformer of the earth leakage circuit breaker when a harmful arc is detected by the arc detection module; and operate the earth leakage circuit breaker by arc/leakage current detection by the arc detection module. To this end, the present invention provides an earth leakage circuit breaker usable as an arc-fault circuit interrupter, the breaker integrally comprising: an earth leakage circuit breaking module including a leakage current detection unit for detecting a leakage current flowing on a circuit; and an arc detection module installed at one side of the earth leakage circuit breaking module, detecting a harmful arc flowing on the circuit to generate an arc blocking signal, and operating the leakage current detection unit of the earth leakage circuit breaking module by the arc blocking signal. Accordingly, the present invention enables an earth leakage circuit breaker to be simply operated by detection of arc/ leakage current by an arc detection module without affecting a function of the earth leakage circuit breaker at all.

Classes IPC  ?

• H01H 33/18 - Moyens pour éteindre ou empêcher des arcs entre organes traversés par le courant utilisant des aimants de soufflage
• H01H 9/44 - Moyens pour éteindre ou empêcher des arcs entre pièces traversées par le courant utilisant des aimants de soufflage
• H01H 83/02 - Interrupteurs de protection, p. ex. disjoncteur ou relais de protection actionné par des conditions électriques anormales autres que seulement les courants excessifs actionnés par courant de défaut à la terre

Abrégé

The present invention relates to a communication method applied to an intelligent advanced metering infrastructure (AMI) system so as to enable metering data collected from an electronic power meter to be wirelessly transmitted to a coordinator via routers, and relates to a technique enabling communication via channels having excellent communication qualities. Such present invention comprises the steps in which: routers check channel quality data for a currently used channel and idle channels, and transmits the results of the checking and GPS data of the routers themselves to a coordinator; the coordinator checks, on the basis of the channel quality data, whether or not handoff requirements are met; and if, as a result of the checking, the coordinator determines that handoff requirements are met, the coordinator issues, to the routers, a channel change command ordering for the currently used channel to be changed to the idle channel having the most excellent communication quality.

Classes IPC  ?

• H04W 36/30 - La resélection étant déclenchée par des paramètres spécifiques par des données de mesure ou d’estimation de la qualité des liaisons
• H04W 36/34 - Contrôle de resélection
• H04W 84/10 - Réseaux à petite échelleRéseaux faiblement hiérarchisés

Abrégé

The present invention relates to a weight processing technique suitable for multi-channel transmission in a wireless LAN (WLAN) system. To this end, a multi-channel transmitter includes a weight processor receiving an output signal, on which subcarrier rearrangement has been performed in a fast Fourier transformer, so as to simultaneously perform a power gain control function required for constantly maintaining an average power level, per subcarrier, which can be changed by channel bonding, and an antenna weight processing function for obtaining a diversity gain, thereby having simple implementation and an effect of improving transmission performance while being suitable for the standard of supporting multi-channel transmission.

Classes IPC  ?

• H04L 5/02 - Canaux caractérisés par le type de signal
• H04L 27/01 - Égaliseurs

Abrégé

The purpose of the present invention is to enable the center frequency of a primary upper frequency channel to be more accurately corrected by, when the center frequency is estimated and compensated in a wireless LAN, estimating the center frequency of a primary frequency channel and correcting an error and thereafter compensating the center frequency on the basis of the correction result. To this end, the present invention comprises: a center frequency estimator for estimating a center frequency error in a signal of the primary frequency channel outputted from a second low-pass filter; a center frequency corrector for correcting a correction value depending on the center frequency position in the center frequency error estimated by the center frequency estimator, calculating a correction value for each position of a primary lower frequency channel, and correcting, on the basis of the correction value, an offset resulting from a sampling frequency error; and a center frequency compensator for compensating a center frequency error for a signal of the primary upper frequency channel outputted from a first low-pass filter, using the center frequency error in the center frequency corrector.

Classes IPC  ?

• H04L 25/17 - Dispositifs d'interpolation

Abrégé

The present invention introduces a MIMO transmission system comprising an envelope detector that obtains distortion information of a power amplifier with an envelope detector, which is simply implementable, thereby minimizing the cost of implementing a feedback pathway, and a method of designing a predistorter constituting a MIMO transmission system that designs the predistorter included in the MIMO transmission system. The MIMO system comprises: a first transmitter; a second transmitter; a feedback pathway unit; and an adaptation algorithm implementation unit. The method for designing a predistorter constituting the MIMO transmission system is used for compensating the distortion of a transmission signal outputted from the MIMO transmission system described in claim 4, and the method comprises the steps of: inputting a training signal; generating an error signal; detecting an envelope signal; generating a digital error signal; and generating a control signal.

Classes IPC  ?

• H04B 7/04 - Systèmes de diversitéSystèmes à plusieurs antennes, c.-à-d. émission ou réception utilisant plusieurs antennes utilisant plusieurs antennes indépendantes espacées
• H03F 1/32 - Modifications des amplificateurs pour réduire la distorsion non linéaire

Abrégé

Disclosed is a wideband signal transmission apparatus including an equivalent power amplifier model for linearizing the nonlinear behavior of a power amplifier included in the transmission apparatus by using baseband predistortion. The wideband signal transmission apparatus comprises a predistorter, a digital-to-analog converter, a modulator, a power amplifier, a demodulator, an analog-to-digital converter, a virtual power amplifier unit, and an adaptive algorithm implementation unit.

Classes IPC  ?

• H04L 25/02 - Systèmes à bande de base Détails
• H04L 27/00 - Systèmes à porteuse modulée

Abrégé

A frequency up and down converter, in which, when down converting a high frequency signal into an intermediate frequency signal or up converting an intermediate frequency signal into a high frequency signal by controlling switching elements using a local oscillator signal, a signal with a frequency to be converted is controlled a number of times during one cycle of the local oscillator signal, whereby the local oscillator signal with a frequency lower than an original frequency may be used. Transistors are added in parallel to switching transistors disposed in a frequency down conversion unit or a frequency up conversion unit, and local oscillator signals with predetermined phases and pulse widths are provided to the gates of the transistors such that a high frequency signal or an intermediate frequency signal is transferred to an output terminal at least two times during one cycle of a local oscillator signal.

Classes IPC  ?

• H04B 1/28 - Circuits pour récepteurs superhétérodynes le récepteur comportant au moins un dispositif à semi-conducteurs ayant trois électrodes ou plus
• H03D 7/14 - Montages équilibrés
• H03D 7/16 - Changement de fréquence multiple

Abrégé

A soft decision decoding method in a multiple-input multiple-output system which respectively receives two simultaneously transmitted data streams, a first transmitting symbol and a second transmitting symbol, in a first receiving signal and a second receiving signal is provided. The soft decision decoding method includes calculating common metrics corresponding to distances between first candidate symbols, which correspond to combinations of all bits that the first transmitting symbol can have, and the first receiving signal using a channel matrix corresponding to a communication channel through which the first and second transmitting symbols are transmitted and determining intermediate nodes between the second receiving signal and the first candidate symbols and nodes between the second receiving signal and second candidate symbols corresponding to combinations of all bits that the second transmitting symbol can have; selecting first nearest candidate symbols that are at a shortest distance from the intermediate nodes on a signal constellation from among the second candidate symbols and determining a soft decision metric for each bit value of the first transmitting symbol based on the first nearest candidate symbols and the common metrics; and determining second nearest candidate symbols based on a logic value of a predetermined bit of each of the second candidate symbols and the positions of the intermediate nodes on the signal constellation and determining a soft decision metric for each bit value of the second transmitting symbol using the second nearest candidate symbols and the common metrics.

Classes IPC  ?

• H04L 1/02 - Dispositions pour détecter ou empêcher les erreurs dans l'information reçue par réception à diversité
• H04L 27/06 - Circuits de démodulationCircuits récepteurs

Abrégé

In a method for estimating a signal-to-noise ratio (SNR) of an orthogonal frequency division multiplexing (OFDM) wireless mobile communication system, noise is estimated from adjacent received signals of at least two adjacent subcarriers and received signals of subcarriers, noise power is calculated by calculating a mean square value of the estimated noise by summing squares of the estimated noise, a mean square value of the received signals is calculated by summing squares of the received signals, signal power is calculated by subtracting the noise power from the mean square value of the received signals, and the SNR is calculated using the signal power and the noise power. Thus, the method of the present invention having low complexity can estimate an SNR efficiently regardless of channel changes on a frequency axis when one OFDM symbol includes preamble data.

Classes IPC  ?

• H04B 3/46 - SurveillanceTests

Abrégé

A method of determining a variable quantization step size is disclosed. In the method of determining a variable quantization step size, a channel characteristic parameter is obtained in order to calculate a quantization step size (Δ) used in channel decoding. The quantization step size (Δ) is variably determined based on the channel characteristic parameter. Therefore, the method of determining a variable quantization step size may improve channel decoding.

Classes IPC  ?

• H04B 7/02 - Systèmes de diversitéSystèmes à plusieurs antennes, c.-à-d. émission ou réception utilisant plusieurs antennes
• H04L 1/02 - Dispositions pour détecter ou empêcher les erreurs dans l'information reçue par réception à diversité
• H04L 5/12 - Canaux caractérisés par le type de signal les signaux étant représentés par différentes modulations de phase d'une seule porteuse
• H04L 23/02 - Appareils ou circuits locaux pour systèmes télégraphiques autres que ceux couverts par les groupes adaptés pour la signalisation orthogonale