Abstract: Provided are an apparatus and method for efficiently computing a log likelihood ratio (LLR) using the maximum a posteriori (MAP) algorithm known as block combining. The method includes the steps of: calculating alpha values, beta values and gamma values of at least two time sections; calculating transition probabilities of respective states in the at least two time sections; performing a comparison operation for some of the transition probabilities to determine the highest value, selecting one of the other transition probabilities according to the determined high value, comparing the determined value with the selected value to select the higher value, and thereby obtaining the highest of the transition probabilities; and determining an operation to apply according to the highest transition probability and calculating an LLR.

Abstract: An optical pickup apparatus includes a light generating unit to generate a light to record or reproduce information, an objective lens to focus the light generated from the light generating unit onto a disk, and a multi-sectional polarizer disposed on a light path between the light generating unit and the objective lens and divided into a plurality of sectors having their individual optical axes.

Abstract: An optical pickup apparatus is provided for use in a recording/reproducing apparatus to record/reproduce information on/from recording media having different formats. Such an optical pickup apparatus comprises a dual wavelength laser diode; a hologram module arranged to split a light which is incident to a recording medium into a plurality of beams; and a photo-detector arranged to receive a light beam reflected from the recording medium and detect an information signal and a signal for servo control. Each of the split beams is focused on a predetermined position corresponding to a format of the recording medium. The light beams reflected from the recording medium are detected by the photo-detector to generate a focus error signal and a tracking error signal. Thus, the optical pickup apparatus records and reproduces information on and from recording media having different formats by using a hologram of a simple pattern.

Abstract: Provided is a turbo decoder with a variable scaling factor. The decoding convergence degree of the turbo decoder is evaluated using a sign difference ratio (SDR) value, the iterative-decoding number is limited, a variable scaling factor is calculated and applied in each decoding convergence area based on the SDR value, and the average number of decoding iterations is reduced.

Abstract: Provided are a low-voltage image sensor and a method of driving a transfer transistor thereof, which are obtained by changing the structure and driving method of a typical transfer transistor of a 4-transistor CMOS transistor, and can eliminate the influence of a voltage or physical structure of a diffusion node on a reset or transfer operation of a photodiode. The image sensor includes a light receiving device for detecting light and a signal conversion unit for reading photocharge generated by the light receiving device to an external circuit. The signal conversion unit includes a transfer transistor including at least two gate electrodes. When the photocharge is transferred to a channel of a transfer gate electrode disposed closest to a photodiode, a transfer gate electrode disposed adjacent to a diffusion node remains turned off.

Abstract: Provided is a driving voltage control module capable of minimizing current consumption and time taken to return from a standby state to a normal state by controlling driving voltages for electronic circuits and systems for communication when a mobile communication transceiving circuit or a communication system is in a standby state in which there is no busy signal. The driving voltage control module includes a regulator for converting an input power voltage into a predetermined level of DC voltage, and supplying the converted DC voltage to an external circuit module as a driving voltage; and a voltage controller for controlling an output voltage level of the regulator, wherein, under control of the voltage controller, a level of the driving voltage is adjusted to be a standby voltage level lower than a turn-on voltage level of a switching device constituting the external circuit module.

Abstract: An object lens for an optical disk may include an aspherical lens surface, and an aspherical equation, which may be applied to form the aspherical lens surface may include two 2nd order function terms. Accordingly, a lens, which has a high numerical aperture (NA) and also has a small flexure on a lens surface or aberration, is provided.

Abstract: A terminal supporting peer-to-peer (P2P) communication, wherein a transceiver of the terminal is implemented to support P2P communication with an adjacent terminal in the same cell. Thus, when short-range communication is possible, the terminal performs P2P communication directly with the adjacent terminal, not via a base station. Consequently, when terminals use different mobile telecommunication service providers or there is no base station network, the terminals can be used for short-range communication. More particularly, when a receiving channel state becomes satisfactory while communication with an adjacent terminal is being performed via a base station, the terminal directly switches to a P2P communication mode and performs communication with the adjacent terminal.

Abstract: A terminal supporting peer-to-peer (P2P) communication, wherein a transceiver of the terminal is implemented to support P2P communication with an adjacent terminal in the same cell. Thus, when short-range communication is possible, the terminal performs P2P communication directly with the adjacent terminal, not via a base station. Consequently, when terminals use different mobile telecommunication service providers or there is no base station network, the terminals can be used for short-range communication. More particularly, when a receiving channel state becomes satisfactory while communication with an adjacent terminal is being performed via a base station, the terminal directly switches to a P2P communication mode and performs communication with the adjacent terminal.

Abstract: An optical pickup apparatus and method for recording and/or reproducing information onto and/or from optical discs having diverse specifications. Particularly, a diffraction grating for use in the optical pickup apparatus includes a substrate for refracting an output beam from a laser diode at a predetermined refractive index, a liquid crystal for refracting the beam, which is transmitted through the substrate, at a different refractive index and direction according to a track pitch of the optical disc, an electrode material for supplying power to the liquid crystal, and a switch for controlling power supply to the electrode material. Electrode materials are aligned with various spacing in order to change the refractive index of the liquid crystal according to the wavelength of a laser and the specification of an optical disc used. Also, power supply to the electrode materials is controlled depending on the optical disc specification.

Abstract: A diffraction element for an optical pick-up apparatus is capable of precisely controlling the tracking of the pick-up apparatus. The diffraction element includes a diffraction grating divided into a first, a second, and a third region. The second region is located between the first and third regions. Any one of the first region and the third region is inclined at a predetermined angle ? with respect to the second region.

Abstract: The present invention provides an efficient data transmission method in BLUETOOTH broadcasting. The method of BLUETOOTH broadcasting generates a first broadcast packet and determines whether a slot is included in an access window. In a case where the slot is not included in the access window, a service interface (SI) information value is set to the assignment information of the slot. The first broadcast packet is then transmitted. A second broadcast packet is then generated and it is determined whether a slot is included in the access window. If the slot is not included in the access window, the SI information value is set to zero. The second broadcast packet is then transmitted. A slave receives the broadcast packets and obtains the SI information values. It is then determined whether the slave transmits data at the next odd numbered slot.

Abstract: Provided is a method and apparatus for transmitting data based on OFDM (Orthogonal Frequency Division Multiplexing). The method includes: forming a plurality of packets suitable for a selected transmission mode from data input to a transmitter; determining a transfer rate of the data; when the data transfer rate is determined to be low and synchronous connection oriented link should be maintained, dividing each of the plurality of packets into a plurality of sub-packets; and transmitting the divided sub-packets, wherein when the divided sub-packets are transmitted, a power supply duration of the transmitter is reduced by using a DPM (dynamic power management) or fine state control unit.

Abstract: Provided is a direct-conversion frequency mixer for down converting a radio frequency (RF) signal into a baseband signal, in which a single phase RF signal and a quadrature location oscillation (quadrature LO) signal are used to generate the baseband signal, the frequency mixer comprising a first frequency mixing unit that uses quadrature LO signals having respective phases of 0 degrees and 180 degrees to directly down-convert the single phase RF signal into the in-phase baseband signal, and a second frequency mixing unit that uses quadrature LO signals having respective phases of 90 degrees and 270 degrees to directly down-convert the single phase RF signal into the quadrature-phase baseband signal, whereby drains and sources of the transistor for receiving the quadrature LO signal and the transistor for receiving the RF signal are connected in common, thus enabling low power source voltage driving.

Abstract: Provided is a wideband active balun circuit based on a differential amplifier. The active balun circuit is configured to compensate for unbalance between two differential signals and can be applied to wideband systems, such as software defined radio (SDR) systems or ultra wideband (UWB) systems. Also, when signal unbalance is caused by changes in process conditions, such as temperature, errors in amplitude and phase between the two differential signals can be finely tuned by adjusting a voltage tuning terminal outside a chip, so that the active balun circuit can simply solve the unbalance between the two differential signals. Furthermore, input transistors that constitute a pair of differential amplifiers are provided in a cascode structure to prevent the occurrence of signal leakage and self-mixture.

Abstract: Provided is a wireless packet communication method, and more particularly, a method and apparatus for enabling low-power communication by providing separate driving clocks optimized for a lower part for performing the function of a physical layer part and an upper part for performing the function of an upper layer above the physical layer in a wireless packet communication system. The method includes a first clock providing step of measuring actual data transmission and reception rates at a predetermined period, setting up a frequency (F1) of a first clock based on the measured rates, and providing the first clock to the upper part and a second clock providing step of determining a transfer mode of the wireless packet communication system, detecting a frequency (F2) of a second clock selected according to the determined transfer mode, and providing the second clock to the lower part.

Abstract: Provided are a pulse signal generator for UWB radio transception and a radio transceiver having the same. The pulse signal generator includes: an envelope generator generating a plurality of envelope signals; a local oscillator array composed of a plurality of high frequency oscillators, each outputting two oscillation signals having a phase difference from each other; a multiplier array receiving the envelope signals and the oscillation signals and outputting signals obtained by respectively multiplying the envelope signals by the oscillation signals; and an I channel adder and a Q channel adder outputting an I channel pulse signal and a Q channel pulse signal by adding output signals having the same phase components among the signals output from the multiplier array, respectively.

Abstract: An optical pickup to improve countermeasure capability of a disc by allowing polarized light of a spot on the disc to become elliptically polarized light includes a light source to emit semiconductor laser light, an objective lens to condense the light emitted from the light source and form an optical spot on a disc, and a wave plate which is rotated such that the spot formed on the disc becomes elliptically polarized light.

Abstract: Provided is a linearization apparatus of a triode region type operational transconductance amplifier that can provide a wide linear input range even when a differential pair input transistor having a short channel length is used at a low power supply voltage. The linearization apparatus of the triode region type operational transconductance amplifier includes: a first transconductor unit for receiving differential pair input voltages through differential pair input transistors and generating a basic transconductance; and a second transconductor unit for receiving the same differential pair input voltages, generating distortion transconductances, and overlapping the basic transconductace with the distortion transconductance for extending a linear range of a final transconductance.

Abstract: Provided is a power amplifier of a low-power consumption system that has linearity at a peak output power while increasing efficiency in a most frequently used range, and thereby enables a battery to last longer. The power amplifier includes an input impedance matcher for impedance-matching a signal input from the outside; a high-power amplifier and a low-power amplifier for amplifying the signal having passed through the input impedance matcher; an amplification controller controlling the high-power amplifier and low-power amplifier according to the power level of the input signal; an output impedance matcher for impedance-matching the signal amplified by the high-power amplifier and low-power amplifier; and a dynamic voltage supplier for supplying the low-power amplifier with a variable driving voltage. With the constitution set forth above, linearity at peak output power is maintained, and efficiency increases in the most frequently used range, thereby enabling the battery of a handheld to last longer.