Abstract: A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.

Abstract: Embodiments of a system for calibrating the image rejection of a receiver include an image-rejection correction circuit that modifies the gain and phase of a first channel of a baseband image signal. The image-rejection correction circuit may include a summing circuit and first and second variable-gain elements. In one implementation, a filter receives a corrected first channel from the image-rejection correction circuit and an unmodified second channel of the image signal, while a controller analyzes power measured at the output of the filter, and adjusts the variable-gain elements to reduce the power of the image signal.

Abstract: A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.

Abstract: An apparatus and method for controlling Transmit (Tx) power when a portable terminal performs human body communication with a counterpart portable device are provided. The apparatus includes a voltage manager for determining whether the Tx power needs to be changed based on an output voltage that is based on a current that varies according to a distance between an electrode of a portable terminal and an electrode of a counterpart portable terminal, and changes the Tx power according to a result of the determination.

Abstract: An identification information reader includes an antenna commonly used for transmission of a radio wave to a radio frequency identification tag and reception of a radio wave that has been modulated with at least identification information and transmitted from a radio frequency identification tag, a transmitter which outputs a radio wave to be transmitted from the antenna, a receiver which demodulates a radio wave received by the antenna to acquire at least the identification information, a directional coupler which is connected between the transmitter and the receiver, guides the radio wave output from the transmitter to the antenna and guides the radio wave received by the antenna to the receiver, and an attenuator which is connected between the antenna and the directional coupler and attenuates the radio wave guided to the receiver to reduce saturation of the receiver due to an increase in voltage standing wave ratio of the antenna.

Abstract: A system and method for protecting a wireless device including co-located network transceivers from uplink starvation are disclosed herein. A wireless device includes a first wireless transceiver and a second wireless transceiver respectively configured for communication via a first wireless network and a second wireless network. The wireless device further includes logic that determines which of the first and second transceivers is enabled to transmit at a given time. The logic determines a duration of a pending transmission via the first transceiver, and determines a predicted start time of a predicted transmission via the second transceiver. Based on the duration and the predicted start time, the logic transmits a notification signal indicating that a receiving device should refrain from transmitting on the first network for a reserved time ending after the pending transmission starts. The pending transmission starts following completion of the predicted transmission.

Abstract: A data transmission system for minimizing the number of errors during Tx/Rx times of mobile service data under mobile environments, and a data processing method for the same are disclosed. The system additionally codes the mobile service data, and transmits the resultant coded mobile service data. As a result, the mobile service data has a strong resistance to noise and channel variation, and can quickly cope with the rapid channel variation.

Abstract: A system (100) and method (300) of feedback transmitter power control can include a transmitter temperature detector such as a thermistor based temperature detector (118), a detector for detecting forward and reflected transmitter power (113 and 115), and a voltage controlled attenuator (120) placed in a radio frequency power control feedback path for modifying transmitter power based on a detected transmitter temperature and a detected forward and reflected transmitter power. The system can further include a logarithmic amplifier controller (122) in the feedback path coupled to the voltage controlled attenuator as well as a power amplifier (112) coupled to the voltage controlled attenuator. The system can operate in both analog and time division multiple access modes. The system can be active in real time throughout a push-to-talk session.

Abstract: Provided is a mobile transmitter and a transmitting method thereof. The mobile transmitter includes a transmission circuit and a control circuit. The transmission circuit selectively operates as a polar transmitter or a direct-conversion transmitter. The control circuit controls an operation of the transmission circuit based on the level of an output signal. The mobile transmitter operates as a direct-conversion transmitter using a linear power amplifier with a high dynamic range when it transmits a low-power signal. Also, the mobile transmitter operates as a polar transmitter using a switching power amplifier with a high power efficiency when it transmits a medium-power or high-power signal. Thus, the mobile transmitter according to the present invention can provide both the high power efficiency (i.e., the advantage of the switching power amplifier) and the high dynamic range (i.e., the advantage of the linear power amplifier).

Abstract: Embodiments of the present invention provide DC biasing circuits. Embodiments employ an open loop scheme, instead of a closed loop scheme as used in conventional circuits. In addition, embodiments generate a DC bias voltage that is independent of temperature, process, and power supply variations. Further, embodiments require low amounts of power and silicon.

Abstract: Disclosed is a portable terminal that includes a main housing; a first sliding housing slidably installed on the main housing in such a manner that the first sliding housing slides in a first direction; second sliding housings slidably installed on the main housing in such a manner that the second sliding housings slide in a second direction; and a sliding module for providing driving force allowing the first and second sliding housings to move, the sliding module being installed on the main housing, wherein the first sliding housing and second sliding housings simultaneously move from each position where they overlap the main housing to each position where they extend from on the main housing.

Abstract: An efficiency controlling module of a power amplifier for wireless communication device includes an attenuator, a filter, and a DC/DC convertor electronically connected in series. The attenuator obtains and attenuates efficiency controlling signals. The filter reduces noise in the efficiency controlling signals. The DC/DC convertor dynamically adjusts an output voltage according to the efficiency controlling signals.

Abstract: A system and method for transmitting a baseband real signal with a non-constant envelope using a polar transmitter involves decomposing a baseband real signal into a non-constant envelope signal of the baseband real signal and a sign signal of the baseband real signal, where the sign signal restores zero crossing regions of the non-constant envelope signal, modulating a carrier signal with the sign signal of the baseband real signal to generate a modulated signal, converting the non-constant envelope signal of the baseband real signal into a voltage signal using a voltage controlled supply regulator, amplifying the modulated signal into an amplified signal based on the voltage signal, and transmitting the amplified signal to an external wireless device.

Abstract: A mobile wireless communications device includes a housing and circuit board in the housing and having radio frequency (RF) circuitry and a power amplifier and microphone mounted thereon. An antenna is carried within the housing and operative with the RF circuitry. An RF shield surrounds and isolates the microphone from the RF circuitry, power amplifier and antenna and shields the microphone from radiated energy generated from the RF circuitry, antenna or power amplifier.

Abstract: There is provided a receiving apparatus including a plurality of antennas, a phase difference detection unit to detect a phase difference of each of a plurality of received signals received by the plurality of antennas, a phase adjustment unit to align phase of the plurality of received signals based on the phase difference detected by the phase difference detection unit, an adding unit to add the plurality of received signals with the phase aligned by the phase adjustment unit together, and a synchronous detection unit to perform synchronous detection using a signal obtained by addition in the adding unit.

Abstract: Implementations and examples of power amplifier devices, systems and techniques for amplifying RF signals, including power amplifier systems based on Composite Right and Left Handed (CRLH) metamaterial (MTM) structures.

Abstract: In a wireless communication apparatus for communicating by using a plurality of antennas, a degree of coupling between antennas is detected before communication is initiated, a combination of antennas is selected based on the degree of coupling and communication is executed using the selected antennas.

Abstract: Circuits, systems, and methods are disclosed for controlling multiple antenna receive paths in a wireless communication device. In some embodiments, the circuit may include a pair of receiving antennas, a first receive path including a VCO coupled to receive a PLL signal and a first mixer coupled to receive a first signal from the VCO and a signal from one of the antennas, and a second receive path integrated separately from the first receive path including a second mixer coupled to receive a second signal from the VCO and a signal from the other antenna. By utilizing the output of the VCO to tune the first and second mixers in the first and second receive paths to the same phase and frequency, control of the multiple antenna receive paths may be optimized.

Abstract: A receiving apparatus comprising: a first mixing unit to output first and second mixed signals each having a first frequency that is a frequency difference between a received signal and a first local oscillator signal, the first and second mixed signals having phases substantially orthogonal to each other; a phase control unit to output second and third local oscillator signals each having a second frequency, the second and third local oscillator signals having a phase difference from each other corresponding to a phase difference between the first and second mixed signals; and a second mixing unit to add a signal obtained by mixing the first mixed signal and the second local oscillator signal, and a signal obtained by mixing the second mixed signal and the third local oscillator signal, to output an intermediate frequency signal having an intermediate frequency that is a difference between the first and second frequencies.

Abstract: Provided are an apparatus and method for transmitting data and an apparatus and method for receiving data, in which beam forming is performed in consideration of the communication capabilities of antennas of stations that perform directional communication in a high-frequency band.