Abstract: An apparatus and a method for removing RX DC in a wireless communication system are provided. A receiver apparatus includes a local oscillator, a mixer for converting a received signal to a baseband signal using a frequency provided from the local oscillator, and a DC compensator, comprising an operational amplifier and a low pass filter, for compensating DC in an output signal of a frequency converter by adjusting a pass band size of the low pass filter.

Abstract: An apparatus and method for amplifying a Transmit (Tx) signal according to an Envelope Tacking (ET) scheme in a wireless communication system are provided. A transmitting end apparatus includes an envelope gain controller for controlling a gain of a digital baseband Tx signal in accordance with power control, a detector for detecting an envelope signal from the digital baseband Tx signal whose gain is controlled, and for shaping on the envelope signal, a first Digital to Analog Converter (DAC) for converting the shaped envelope signal into an analog signal, and an envelope modulator for generating a drain bias of a power amplifier that amplifies a Radio Frequency (RF) Tx signal by using the analog envelope signal. Accordingly, a digital-based ET scheme is implemented, and by using a plurality of shaping tables, efficiency of the ET scheme can be maximized in a transmitting end that uses power control.

Abstract: An apparatus and method for amplifying a Transmit (Tx) signal according to an Envelope Tacking (ET) scheme in a wireless communication system are provided. A transmitting end apparatus includes an envelope gain controller for controlling a gain of a digital baseband Tx signal in accordance with power control, a detector for detecting an envelope signal from the digital baseband Tx signal whose gain is controlled, and for shaping on the envelope signal, a first Digital to Analog Converter (DAC) for converting the shaped envelope signal into an analog signal, and an envelope modulator for generating a drain bias of a power amplifier that amplifies a Radio Frequency (RF) Tx signal by using the analog envelope signal. Accordingly, a digital-based ET scheme is implemented, and by using a plurality of shaping tables, efficiency of the ET scheme can be maximized in a transmitting end that uses power control.

Abstract: Disclosed is a multi-mode/multi-band wireless transceiver. The multi-mode/multi-band wireless transceiver includes a tunable duplexer including transmission and reception channel filters of which transmission and reception channel filtering frequencies respectively are controlled by an external element; and a control portion for controlling the transmission and reception channel filtering frequencies to correspond to transmission and reception channels of a current service band. Thus, a use of a RF SAW filter is unnecessary, while it is possible to support the multi-mode/multi-band using a tunable duplexer. Therefore, the number of parts and volume of the transceiver can be reduced, and it is possible to weaken a specification of an RF system.

Abstract: An apparatus and method for compensating for nonlinearity of a portable communication terminal are provided. The apparatus includes a modem for modulating Transmission (Tx) data, a Digital Pre-Distortion (DPD) mode controller for obtaining power level information and for determining a power on/off state of a DPD unit by using the obtained information in the Tx mode, and the DPD unit for outputting the modulated data input from the modem without performing a DPD operation when power is off, and for outputting the modulated data input from the modem by performing the DPD operation when power is on.

Abstract: A transmitter of a mobile communication terminal including a transmission signal processor for receiving a data signal to be transmitted, modulating the data signal into a radio signal, and outputting the radio signal. A local oscillator device provides the transmission signal processor with a local oscillator signal and a modem for outputs a control signal to power on the transmission signal processor and the local oscillator device when a voice signal is input through a microphone. A delay device for delays the control signal from the modem and provides the transmission signal processor with the delayed control signal.

Abstract: A method and apparatus are provided for removing cross modulation (CM) noise in a wireless transceiver. A determination is made as to whether a transmission signal to be supplied to a transmitter of the wireless transceiver is present. If the transmission signal is present, a level of the transmission signal is determined. When a value of the transmission signal level is equal to or greater than a predetermined value, a first number of filtering operations are performed on a received signal to be input into a receiver of the wireless transceiver. However, when no transmission signal is present or the value of the transmission signal level is less than the predetermined value, a second number of filtering operations are performed on the received signal to be input into the receiver of the wireless transceiver. The first number of filtering operations being greater than the second number of filtering operations.

Abstract: A multimode/multiband mobile station and a method for operating the same are provided. A transmission module transmits multimode/multiband signals through transmitters. A reception module receives radio signals for different services of the same frequency band among multimode/multiband signals through receivers for the same frequency band, and receives radio signals of different frequency bands among the multimode/multiband signals through receivers for the different frequency bands. As compared with the conventional mobile station, the multimode/multiband mobile station can reduce the number of receivers by making use of one receiver to receive radio signals for different services of the same frequency band. The multimode/multiband mobile station can use a duplexer of the conventional frequency division duplex (FDD) technique (e.g., wideband code division multiple access (WCDMA)) in a time division duplex (TDD) technique (e.g.

Abstract: Disclosed is a multi-mode/multi-band wireless transceiver. The multi-mode/multi-band wireless transceiver includes a tunable duplexer including transmission and reception channel filters of which transmission and reception channel filtering frequencies respectively are controlled by an external element; and a control portion for controlling the transmission and reception channel filtering frequencies to correspond to transmission and reception channels of a current service band. Thus, a use of a RF SAW filter is unnecessary, while it is possible to support the multi-mode/multi-band using a tunable duplexer. Therefore, the number of parts and volume of the transceiver can be reduced, and it is possible to weaken a specification of an RF system.

Abstract: Disclosed is an apparatus for controlling the input 3rd order Intercept Point (IIP3) in a multi-mode multi-band wireless transceiver. The apparatus includes: a mixer for down-converting an incoming wireless signal which is received through each frequency band and is then low noise-amplified; a baseband chip for providing mixer IIP3 control information according to a current mode and transmission power level of the wireless transceiver; and a mixer IIP3 controller for controlling the IIP3 of the mixer based on the IIP3 control information. In a wireless transceiver without a band pass filter between a low noise amplifier and a mixer, the apparatus does not always increase the IIP3 of the mixer, but increases the IIP3 of the mixer in a wireless transceiver only when it is necessary to increase the IIP3. Therefore, the apparatus can reduce wasteful power consumption.

Abstract: A method of canceling noise of a reception module in a wireless transceiver including the steps of determining a filtering band using channel information; generating a switching control signal, selecting a filter to perform filtering according to the determined filtering band; and switching a receive signal received through an antenna of the reception module to the selected filter to perform the filtering using the switches controlled by the switching control signal; and filtering the receive signal using the selected filter. Accordingly, cross modulation (CM) noise of the reception module is canceled.

Abstract: A method and apparatus are provided for removing cross modulation (CM) noise in a wireless transceiver. A determination is made as to whether a transmission signal to be supplied to a transmitter of the wireless transceiver is present. If the transmission signal is present, a level of the transmission signal is determined. When a value of the transmission signal level is equal to or greater than a predetermined value, a first number of filtering operations are performed on a received signal to be input into a receiver of the wireless transceiver. However, when no transmission signal is present or the value of the transmission signal level is less than the predetermined value, a second number of filtering operations are performed on the received signal to be input into the receiver of the wireless transceiver. The first number of filtering operations being greater than the second number of filtering operations.

Abstract: A GPS signal receiving method in a mobile terminal having a first reception path and a second reception path is provided. Upon request for GPS signal reception while receiving a CDMA signal in the first reception path, the received strength of a GPS signal is measured. If the GPS signal strength is equal to or greater than a predetermined threshold, the GPS signal is received in the first reception path. If the GPS signal strength is less than the predetermined threshold, the GPS signal is received in the second reception path.

Abstract: A mobile communication terminal including a Global Positioning System (GPS) reception unit for receiving a GPS signal. A camera unit takes a picture in response to input of a picture-taking request signal. A memory unit stores the taken picture and picture-taking location information. A control unit generates the picture-taking location information using the GPS signal, and controls an operation for storing the taken picture and the generated picture-taking location information together. The mobile communication terminal stores a picture of a predetermined place and picture-taking location information, such that a user can clearly identify the predetermined place or location, and can easily locate and go to the place or location.

Abstract: A temperature compensation device for an automatic gain control loop in a receiver of a mobile communication terminal is disclosed. The temperature compensation device comprises a thermistor having a resistance varying with temperature to vary its output voltage, an analog/digital converter for converting the output voltage from the thermistor into a digital signal, and a temperature compensator for outputting a temperature compensation value in response to a digital signal based on a specific temperature variation from the analog/digital converter.

Abstract: A transmitter of a mobile communication terminal including a transmission signal processor for receiving a data signal to be transmitted, modulating the data signal into a radio signal, and outputting the radio signal. A local oscillator device provides the transmission signal processor with a local oscillator signal and a modem for outputs a control signal to power on the transmission signal processor and the local oscillator device when a voice signal is input through a microphone. A delay device for delays the control signal from the modem and provides the transmission signal processor with the delayed control signal.

Abstract: An apparatus and method for receiving a quick paging message in a mobile station wherein a controller for synchronizing with a second clock in a predetermined time slot and transmitting a command for obtaining a synchronization at a frequency of receiving the quick paging message where the MS selects a clock having a first period as an operation clock under the second mode and under the first mode, selects a clock having a second period earlier than the first period; a dual phase-locked loop operating in response to the clock selected by the controller, for synchronizing with frequency in response to the command from the controller; a oscillator for oscillating at the synchronized frequency with the dual phase-locked loop; and a radio frequency part for receiving the quick paging message over a forward quick paging channel synchronously with the oscillating frequencies.

Abstract: A GPS signal receiving method in a mobile terminal having a first reception path and a second reception path is provided. Upon request for GPS signal reception while receiving a CDMA signal in the first reception path, the received strength of a GPS signal is measured. If the GPS signal strength is equal to or greater than a predetermined threshold, the GPS signal is received in the first reception path. If the GPS signal strength is less than the predetermined threshold, the GPS signal is received in the second reception path.

Abstract: A temperature compensation device for an automatic gain control loop in a receiver of a mobile communication terminal is disclosed. The temperature compensation device comprises a thermistor having a resistance varying with temperature to vary its output voltage, an analog/digital converter for converting the output voltage from the thermistor into a digital signal, and a temperature compensator for outputting a temperature compensation value in response to a digital signal based on a specific temperature variation from the analog/digital converter.

Abstract: An apparatus and method for receiving a quick paging message in a mobile station wherein a controller for synchronizing with a second clock in a predetermined time slot and transmitting a command for obtaining a synchronization at a frequency of receiving the quick paging message where the MS selects a clock having a first period as an operation clock under the second mode and under the first mode, selects a clock having a second period earlier than the first period; a dual phase-locked loop operating in response to the clock selected by the controller, for synchronizing with frequency in response to the command from the controller; a oscillator for oscillating at the synchronized frequency with the dual phase-locked loop; and a radio frequency part for receiving the quick paging message over a forward quick paging channel synchronously with the oscillating frequencies.