Abstract: A semiconductor laser device has at least one semiconductor laser element, a heat sink having a first bearing area, on which the at least one semiconductor laser element bears, a housing upper part and a housing lower part, which, in the interconnected state, can at least partly surround the semiconductor laser element, and also a sealing for the tight connection of housing upper part and housing lower part. The heat sink services as housing lower part.

Abstract: The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect, the effects of the kink region may be compensated for by utilizing a lookup table. A sample of the optical power of an amplified optical signal may be used to select an entry in the lookup table that compensates for non-linearities in the kink region. In yet a further aspect, a lookup table may be used to control a pulse modulator to compensate for non-linearites in the kink region of the L-I curve.

Abstract: A method and apparatus for preventing laser current saturation (18) in high-speed optical drives. Saturation in laser current in high-speed optical drives is prevented before limitations in laser power are observed allowing the system to maintain requests for increases in the laser power. The saturation in laser current problem that is apparent at high temperatures and at high writing powers especially when combined with low supply voltage is avoided by insured operation of the laser near but below saturation. The ability to increase laser power upon request is maintained providing for good writing quality resulting and usable. The potential onset of laser current saturation is detected (34) and avoided (36) by dropping to a lower write speed requiring less laser power and hence preventing laser current saturation.

Abstract: A semiconductor laser light emitting circuit includes a semiconductor laser diode emitting a laser light by modulating a current supplied thereto, a light intensity detection circuit that detects the laser light and generates a voltage, and a voltage-current conversion circuit converting a voltage into a current supplied to the laser diode. A S/H capacitance is provided to store electric charge and output a voltage to the voltage/current conversion circuit. A first operational amplifier is provided to output a first current charging the S/H capacitance. A rapidly charging circuit is provided to charge the S/H capacitance with a second current. The rapidly charging circuit terminates charging when the voltage is equal to or more than a second reference voltage.

Abstract: To provide a laser processing apparatus compatible with increase in the output of the pumping light source without increasing the reflectance of the output mirror.

Abstract: A system and a method of manufacture for a semiconductor laser with a continuous waveguide ridge extending the length of the laser. The continuous waveguide ridge is positioned through the center of the optical components of the semiconductor laser. The optical components including the waveguide ridge may be distributed Bragg reflectors (DBRs), outcoupling gratings, and phase controllers. The illustrated embodiments include lateral-grating grating-stabilized edge-emitting lasers and lateral-grating grating-stabilized surface-emitting (GSE) lasers. Both loss-coupled and non-loss-coupled lateral-grating components are illustrated.

Abstract: The present invention relates to a high-power semiconductor laser having low divergence and low astigmatism, this laser being including, in an active layer, a first part in the form of a narrow monomode stripe with transverse index guiding terminating in a second part flaring out from the first part, also with transverse index guiding.

Abstract: A semiconductor laser diode apparatus capable of suppressing variation in an emission position and an emission direction of a laser beam emitted from a semiconductor laser diode element is obtained. This semiconductor laser diode apparatus includes a semiconductor laser diode element having warping along either a first direction in which a cavity extends or a second direction intersecting with the first direction and a base on which a convex side of the warping of the semiconductor laser diode element is fixed, wherein a distance between a first end of the semiconductor laser diode element in a direction of larger warping among the first and second directions and the base is smaller than a distance between a second end of the semiconductor laser diode element in the direction of the large warping among the first and second directions and the base.

Abstract: A beam delivery system of a projection exposure system comprises a laser generating a beam of laser light from a plurality of longitudinal laser modes in a cavity, wherein light generated by a single longitudinal laser mode has an average line width ?lat, wherein the laser light of the beam has, at each of respective lateral positions of the beam, a second line width ?lat corresponding to lateral laser modes, and wherein the laser light of the beam has, when averaged over a whole cross section thereof, a line width ?b corresponding to plural lateral laser modes, and wherein ?m<?lat<?b, and wherein an optical delay apparatus disposed in the beam provides an optical path difference ?l, wherein 0.8 · ? 0 2 ( 2 · ? ? ? ? l ) < ? ? ? l < 1.8 · ? 0 2 ( 2 · ? ? ? ? l ) , wherein ?0 is an average wavelength of the light of the first beam of laser light, and ??lat represents the second line width.

Abstract: In a symmetrically stable optical resonator, a first reference plane is set at an arbitrary position between the end face (102), opposing a partial reflector (2), and the neutral point (101) of a rod type solid state laser medium (1), and an aperture (5) having a diameter substantially equal to that of the rod type solid state laser medium (1) is arranged at a position optically symmetric to the reference plane with the partial reflector (2) as a neutral point using a relay lens (6) and a coupling lens (7) arranged between the aperture (5) and an optical fiber (8), the first reference plane is transfer-relayed onto the incident end face of the optical fiber (8), and the aperture (5) is transferred onto the coupling lens (7) through the relay lens (6).

Abstract: A monoblock laser cavity includes a plurality of discrete optical components disposed serially on a substrate and sharing a common optical axis. The optical components include a laser rod of gain material, a Q-switch, an OPO crystal, and an output coupler. The output coupler has at least one convex end face to improve the beam quality.

Abstract: The inductor of a melting furnace also comprising a crucible, consists of parallel but oblique conductors and forming a wave around the crucible, with at least one descending portion (9) and one ascending portion (10). The benefit from this arrangement is that the conductors are at an identical average height and all comprise a portion located at each heating height, which guarantees density uniformity of the currents flowing in the conductors even if the load of the crucible has superimposed regions for which the electrical resistivity is different.

Abstract: Embodiments disclosed herein provide a non-intrusive thermal (NIT) monitor for sensing temperatures useful for semiconductor manufacturing applications. In some embodiments, a NIT monitor comprises a thermopile, a fluid housing with a fluid window, and an elongated member positioned between the thermopile and the fluid window for transmitting or reflecting infrared signals corresponding to a temperature of a fluid in the fluid housing. The fluid housing may have a cross-sectional profile to enable the manipulation of the fluid flow under the fluid window, enhancing the speed and accuracy of the temperature sampling. The elongated member, which may be hollow and coated with gold, may an extended piece of the fluid housing or a part of an optics housing. In some embodiments, the NIT monitor is connected to a main conditioning circuit board via a cable for processing the temperature measurements at a remote location.

Abstract: A vacuum processing chamber for measuring the temperature of a surface of an object comprising a cap is provided. The cap has a non-deformable end wall of thermally conducting material and a side wall connected thereto. An outside surface of the end wall is shaped to conform to a shape of the object surface to be measured. A surface on an inside of the end wall of the cap emits electromagnetic radiation having a detectable optical characteristic that is proportional to the temperature of the cap end wall. The vacuum processing chamber further comprises a light wave guide having one end held within the cap a distance from the radiation emitting element and in optical communication therewith.

Abstract: In a transmission method of the present invention, when transmitting an information bit from a transmitter to a receiver, an encoder of the transmitter firstly inputs and encodes the information bit, and a modulator then modulates the encoded information bit to create a modulation symbol. A spreader spreads the obtained modulation symbol using a rotation orthogonal code having a rotation angle that is appropriate to a combination of the modulation method and the coding rate, and transmits it to a transmission path. The receiver performs a reverse operation of the transmitter, and decodes the information bit. In QPSK modulation where the coding rate of an error-correction code is ½, when a rotation angle that obtains a same signal point as OFDM is 0°, spreading is performed using a rotation orthogonal code having a rotation angle of between 17° and 45°, or between ?17° and ?45°, thereby reducing bit error and enabling highly-reliable communication to be achieved.

Abstract: A method for receiving spread spectrum signals and for initial code acquisition from the received signals comprises de-spreading the received signals, based on code phase synchronization, to produce a de-spread signal; and performing a modulation detection based on a change of time-domain characteristic of the de-spread signal.

Abstract: A repeater environment is provided to operatively deploy a feedback cancellation loop that performs closed loop calculations for weights used by a feedback equalizer to improve signal integrity and amplification. In an illustrative implementation, an exemplary repeater environment comprises a transmitter, a receiver, an equalized feedback cancellation loop circuitry operative to perform one or more closed form calculations for equalizer weights. In the illustrative implementation, the feedback cancellation loop can comprise a calculation module operative to perform one or more closed form weight calculations using linear algebraic techniques as part of feedback signal cancel operations for use by the N tap feedback equalizer canceller.

Abstract: A repeater environment is provided operative to deploy a feedback cancellation loop that is adaptively coupled with an antenna array such that a selected metric can be derived by deploying a selected filter bank operative to process the signal on a bin by bin basis and the derived metric can be applied to the antenna array and feedback cancellation loop combination to improve signal integrity and amplification. In an illustrative implementation, an exemplary repeater environment comprises, a transmitter, a receiver, an equalized feedback cancellation loop circuitry comprising a filter bank, the cancellation loop being operatively coupled to an antenna array. In the illustrative implementation, the feedback cancellation loop can receive signals as input from a cooperating antenna array and provide output signals such as a feedback leakage signal to a cooperating antenna array.

Abstract: A repeater environment is provided to deploy a feedback cancellation loop that is adaptively coupled with an antenna array such that a selected metric can be derived by deploying a one or more of selected metrics (e.g., composite metrics) comprising a selected filter bank operative to process the signal on a bin by bin basis and the derived metric can be applied to the antenna array and feedback cancellation loop combination to improve signal integrity and amplification, beam forming operations, and pilot control and overhead channel control operations. In an illustrative implementation, an exemplary repeater environment comprises, a transmitter, a receiver, an equalized feedback cancellation loop circuitry comprising a filter bank, the cancellation loop being operatively coupled to an antenna array.

Abstract: A data transmission device for sending back data on a reflected wave of an unmodulated carrier, the data transmission device includes: an antenna adapted to receive an unmodulated carrier Fo from a data reader with which data is to be exchanged and send a reflected wave of the unmodulated carrier Fo to the data reader; subcarrier oscillation means for generating a subcarrier frequency Fs; subcarrier modulation means for digitally modulating sending data on the subcarrier Fs; D/A conversion means for generating the analog modulated subcarrier wave Fs by converting a digital modulated signal, generated by the subcarrier modulation means, into analog form; and frequency mixing means for mixing the unmodulated carrier Fo and modulated subcarrier wave Fs to generate new modulated waves Fo+Fs and Fo?Fs.

Abstract: Automatic rate negotiation logic for a high speed serial interface in a programmable logic device determines whether multiple occurrences of a single-bit transition (i.e., a data transition from “0” to “1” to “0” or from “1” to “0” to “1”) occur within a predetermined time interval on a data channel of a high-speed serial interface. The interval preferably is selected such that multiple occurrences of a single-bit transition mean that the data channel is operating in full-rate mode. The rate negotiation logic may share a phase detector with clock data recovery circuitry in the interface. The phase detector may be a bang-bang phase detector specially adapted to detect single-bit transitions.

Abstract: The present invention concerns a method for determining a corrected estimated variance representative of the condition of reception of signals representative of symbols transferred by an emitter to a receiver through a communication channel, wherein the method comprises the step, executed by the receiver, of producing an estimation of the variance by a Wiener channel estimator comprising a linear filter of which coefficients are determined at least from a given average signal to interference plus noise ratio value, the method being characterised in that it comprises farther step, executed by the receiver, of: multiplying the estimation of the variance by a correction factor, the value of the correcting factor being dependent at least on the number of coefficients of the linear filter of the Wiener channel estimator.

Abstract: A method and architecture for pulse shaping are provided. The architecture includes a pulse shaping filter having a plurality of memory elements and a plurality of taps connected to the plurality of memory elements wherein a total number of the plurality of taps is independent of a sampling rate. The pulse shaping filter further includes a selector configured to select outputs from the plurality of taps to define a pulse shaped output.

Abstract: Systems and methods for a wireless communication system are provided. The method includes estimating a time-variation of a channel through which the wireless communication system transmits. This also includes decreasing the estimated time-variation of the channel from a signal transmitted by the wireless communications system.

Abstract: Herein described are at least a method and a system for implementing a high speed Tomlinson-Harashima Precoder. The method comprises using an L-tap transpose configuration of a Tomlinson-Harashima Precoder and processing a first discrete time sampled sequence using said L coefficients and L state variables by clocking the L-tap Tomlinson-Harashima Precoder using a clock signal wherein the clock signal has a clock rate equal to one half the symbol rate of the discrete time sampled sequence. In a representative embodiment, an L-tap Tomlinson-Harashima Precoder comprises a single integrated circuit chip, wherein the integrated circuit chip comprises at least one circuitry for processing a discrete time sampled sequence using L coefficients and L state variables by way of clocking the discrete time sampled sequence using a clock signal having a clock rate that is one half the symbol rate of the discrete time sampled sequence.

Abstract: A digital controller for dc-dc switching converters can operate under light load conditions. The controller can be suitable for the use in switch-mode power supplies providing regulated output voltage for handheld devices and other low-power electronics. To create long time intervals, compared to the propagation time of digital logic a DPFM/DPAM can use a ring oscillator with two sets of delay cells and two signals racing around the ring.

Abstract: The present invention discloses a multifunctional video encoding circuit system capable of performing six types of operations: addition, subtraction, multiplication, multiply-accumulation, interpolation, and absolute difference summation. A partial product generation part, a partial product reduction part and an accumulation part of the circuit system are equipped with a virtual power suppression unit each for reducing the power consumption of the partial product generation part, the partial product reduction part and the accumulation part, so as to reduce the power consumption of the multifunctional video encoding circuit system.

Abstract: A digital video apparatus and method thereof are disclosed. The digital video apparatus includes: a first decoder, for receiving an input video signal and decoding the input video signal to generate a transformed video signal; a processor, for processing the transformed video signal, and accessing the transformed video signal in a storage device; and a first encoder, for receiving the transformed video signal, encoding the transformed video signal and outputting an encoded transformed video signal.

Abstract: Moving-picture-with-audio data suitable for reproduction at a terminal device is generated rapidly. Image data, which represents a moving picture from which audio has been removed, and audio data are extracted from moving-picture-with-audio data by an image extracting unit and audio extracting unit. The items of extracted image data and audio data are respectively converted by an image converting unit and audio converting unit to image data and audio data having formats of a plurality of types suitable for reproduction and output by every model of terminal device. The items of image data and audio data obtained by the conversions are stored in an image database and audio data base, respectively. When the moving-picture-with-audio data is to be transmitted, items of image data and audio data suited to a terminal device to which the transmission is to be made are read out and the moving-picture-with-audio data is generated.

Abstract: A contents reproducing apparatus includes a receiving unit configured to receive a first packet having an ES in which encoded video or audio data is stored, and a second packet having the ES and a PCR, a counter configured to count a STC and output the counted STC as a STC value, a buffer configured to store the first and second packets in an order of reception in a time shift reproduction mode and a time shift storage mode, a correcting unit configured to correct the PCR included in the second packet received by the receiving unit by using the STC value and output the corrected PCR, in the time shift reproduction mode, and a control unit configured to control the STC in accordance with the corrected PCR and the STC value, in the time shift reproduction mode.

Abstract: An encode control strategy is provided for variable bit rate encoding of a sequence of video frames in a single pass. The control strategy includes determining whether a video frame has a complexity level statistically outside a defined range from a complexity level of at least one preceding frame of the sequence of video frames, and if so, determining a new average bit rate target for the video frame. The new average bit rate for the video frame is determined employing at least one of spatial complexity and temporal complexity of the video frame. The new average bit rate target for the video frame is used to set frame level bit rate control parameter(s), and the video frame is encoded using the set frame level bit rate control parameter(s).

Abstract: A technique of encoding video frames allocates an available number of bits to different portions of the video frame. A processing unit identifies a region of interest (ROI) in a video frame, and computes a first and second complexity parameter respectively representing the change in video information in the ROI portions and non-ROI portions in the video frame relative to a reference frame. Bits are allocated to the ROI portion proportional (positive correlation) to the first complexity parameter and a ratio of the area of the ROI to the area of the frame. The remaining available bits are allocated to the non-ROI. In an embodiment, the bits are encoded according to H.264 standard.

Abstract: A constant-quality rate control system and algorithm for multiple encoders with a single video source are disclosed. The system comprises a base encoder, a region of interest (ROI) detector, and at least one ROI encoder. The base encoder encodes a base video sequence which is a down-sampled version of a video sequence and sends the base video sequence to a multiplexer. The ROI detector extracts an ROI video sequence from the original video sequence. The ROI encoder encodes the ROI video sequence and sends it to the multiplexer. The ROI encoder uses information obtained during encoding of the base video sequence to improve the encoding of the ROI video sequence.

Abstract: A decoder (10) conceals errors in a coded image comprised of a stream of macroblocks by examining each macroblock for pixel errors. If such errors exist, then each of at least two macroblocks pictures from each of two different pictures are weighted to yield a weighted prediction (WP) for estimating missing/corrupt values to conceal the macroblock found to have pixel errors.

Abstract: Method for coding a video signal using hybrid coding, comprising: reducing temporal redundancy by block based motion compensated prediction in order to establish a prediction error signal; performing quantization samples of the prediction error signal or on coefficients resulting from a transformation of the prediction error signal into the frequency domain to obtain quantized values, representing quantized samples or quantized coefficients respectively; calculating a quantization efficiency for the quantized values; calculating a zero efficiency for a quantization, when the quantized values are set to zero; selecting the higher efficiency; and maintaining the quantized values or setting quantized values to zero, for further proceeding, depending on the selected efficiency.

Abstract: A so-called inter-macroblock parallelism is proposed for motion estimation. First, pixel data of one of the consecutive candidate blocks in an overlapped region of search windows of current blocks in a reference frame including reference blocks corresponding to the current blocks are read and transferred to a plurality of processing element (PE) arrays in parallel. The plurality of PE arrays are used to determine the match situation of the current blocks and the reference blocks. Then, the above process is repeated for the rest of the candidate blocks in sequence. For example, if there are four current blocks CB1-CB4 and four consecutive candidate blocks, at the beginning the data of the first candidate block are read and transferred to four PE arrays in parallel, and so to the second, third and fourth candidate blocks in sequence, and the four PE arrays calculate SADs for CB1 to CB4, respectively.

Abstract: A video processing system is provided with video encoding apparatus 1 and video decoding apparatus 2. The encoding apparatus 1 outputs a maximum delay time that is incurred by backward prediction, in addition to encoded data D1 resulting from encoding of video data D0. The decoding apparatus 2 effects input of the maximum delay time that is incurred by backward prediction, in addition to encoded data D1 from the encoding apparatus 1. Then the decoding apparatus 2 decodes the encoded data D1 with reference to the input maximum delay time to generate motion video data D2.

Abstract: In one embodiment, a method for parallel processing of blocks in a decoding process is provided. A plurality of blocks for a picture is received. The picture may have the plurality of blocks arranged in a first order. The blocks in the plurality of blocks may be pre-processed to determine data dependency information for blocks. In one embodiment, the blocks in the picture are all pre-processed to determine the data dependency information for every block in the picture if possible. Blocks that do not have data dependencies are then determined and sent for parallel processing in processing units. Also, blocks that still have data dependencies are not processed until the data dependency information becomes available. For example, an inter-coded block may be decoded and information for the decoded block is used to decode the intra-coded block. At this point, these blocks may be sent for processing in the processing units.

Abstract: A video processing device operates in an encoding mode when a mode selection signal has a first value and operates in a decoding mode when the mode selection signal has a second value. The encoding mode utilizes a plurality of function specific hardware engines that each perform a specific coding function and the decoding module utilizes at least one of the plurality of hardware engines.

Abstract: A system and method for providing improved residual prediction for spatial scalability in video coding. In order to prevent visual artifacts in residual prediction in extended spatial scalability (ESS), each enhancement layer macroblock is checked to determine if the macroblock satisfies a number of conditions. If the conditions are met for an enhancement layer macroblock, then it is likely that visual artifacts will be introduced if applying residual prediction on the macroblock. Once such locations are identified, various mechanisms may be used to avoid or remove the visual artifacts.

Abstract: An apparatus and corresponding method are provided for selecting one of several alternate input streams for transmission, the method including determining bandwidth requirements for each of the alternate input streams, measuring bandwidth currently available for transmission, and selecting for transmission one of the alternate input streams that has the highest determined bandwidth requirement less than or equal to the measured bandwidth currently available for transmission.

Abstract: The invention includes: a bitstream updating output unit configured to receive a bitstream and update a syntax element located at a beginning of the bitstream according to a code length thereof and outputs the syntax element; a bitstream decoding unit configured to decode, in response to a decode request, a variable-length code of the syntax element outputted from the bitstream updating output unit; a zerosLeft updating unit configured to update zerosLeft based on a specific syntax element decoded by the bitstream decoding unit; a run_before remaining number updating unit configured to update a run_before remaining number based on a specific syntax element decoded by the bitstream decoding unit; and a syntax selection unit configured to select a syntax element to be decoded by the bitstream decoding unit. Thus, multiple zero run_before syntaxes and one non-zero run_before syntax, or multiple zero run_before syntaxes are decoded all at once.

Abstract: A video coding method comprises dividing a coefficient vector into two or more sub-vectors, each sub-vector having a length less than or equal to a length of the coefficient vector, indicating a size of each sub-vector and a position of each sub-vector within the coefficient vector, and forming a block corresponding to each sub-vector

Abstract: A picture decoding device (100) comprises a decoding unit (30), a frame memory (40), a deblocking filter (50), a macro block memory (60), and a control unit (70). The macro block memory (60) stores an unfiltered picture data, for which deblock-filtering is not performed, of the macro blocks adjoining a slice boundary. Decoding and deblock-filtering are performed for the macro blocks of each slice in a manner of pipeline processing, and the decoded picture data for the macro blocks is stored in the frame memory (40). After the pipeline processing for all of the macro blocks is completed, the second deblock-filtering is performed to the slice boundary-adjoining macro blocks, and the pixel values of the slice boundary-adjoining macro blocks already stored in the frame memory (40) are replaced. Thereby, the encoded picture data of arbitrary slice order can be completely decoded.

Abstract: A dynamic AC prediction technique is implemented in a data partition mode which automatically disables AC prediction for encoding the current macroblock in the next packet when packet overflow occurs. Otherwise, when there is no overflow, AC prediction remains enabled to maintain compression efficiency. More particularly, in the preferred embodiment, a determination is first made whether a macroblock causes a packet overflow if it is encoded in the current packet. If so, a new packet is initiated into which the macroblock is encoded without AC prediction as the first macroblock. Otherwise, the macroblock with AC prediction remains in the current packet and a new macroblock is encoded.

Abstract: An apparatus and method for decoding data in a digital broadcasting receiver are disclosed, in which first payload data obtained by RS decoding of input RS packet data is buffered in a first buffer, packet data failed in the RS decoding is buffered in a second buffer, an erasure RS decoding is performed on the first payload data using erasure information indicating whether the first payload data has errors and if the first payload data has errors, indicating the positions of the errors, payload data failed in the erasure RS decoding is overwritten on payloads of the packet data buffered in the second buffer, second payload data obtained by RS decoding of the overwritten packet data is overwritten in the first buffer, an erasure RS decoding is performed on the second payload data buffered in the first buffer, and the RS decoding and erasure RS decoding are repeated until errors of the second payload data are corrected.

Abstract: A real-time MPEG video coding system with information look-ahead for constant bit rate (CBR) applications, such as, for example, Video-on-Demand (VoD) over ADSL. This scheme employs two MPEG encoders. The second encoder has a buffer to delay the input by an amount of time relative to the first encoder to create a look-ahead window. In encoding, the first encoder collects the information of statistics and rate-quality characteristics. An on-line information processor then uses the collected information to derive the best coding strategy for the second encoder to encode the incoming frames in the look-ahead window. The second encoder uses the encoding parameters from the processor as the coding guide to execute the coding strategy and generate the final bitstream.

Abstract: A multi-user MIMO downlink beamforming system (200) is provided to enable transmit beamforming vectors to be efficiently provided to a subset of user equipment devices (201.i), where spatial separation or zero-forcing transmit beamformers (wi) are computed at the base station (210) and used to generate precoded reference signals (216). The precoded reference signals (216) are fed forward to the user equipment devices (201.i) which apply one or more hypothesis tests (207.i, 208.i) to the precoded reference signals to extract the precoding matrix (W), including the specific transmit beamforming vector (wUE) designed for the user equipment, and this extracted information is used to generate receive beamformers (vi).

Abstract: A sampling offset estimation apparatus including a pilot sub-carrier refiner, an information sub-carrier refiner, a data sub-carrier refiner, and a sampling offset estimator. The pilot sub-carrier refiner to refine a pilot sub-carrier extracted from a differential demodulated signal, and to generate a reference pilot sub-carrier. The information sub-carrier refiner to refine an information sub-carrier extracted from the differential demodulated signal, and to generate a reference information sub-carrier. The data sub-carrier refiner to refine a data sub-carrier extracted from the differential demodulated signal, and to generate a reference data sub-carrier. The sampling offset estimator to estimate a sampling offset included in the differential demodulated signal, on a basis of the reference pilot sub-carrier, the reference information sub-carrier, and the reference data sub-carrier.

Abstract: An apparatus for generating a precoding matrix codebook includes a matrix group generator to generate a first group of unitary matrices based on a vector-based codebook for precoding of a multiple input multiple output (MIMO) communication scheme; a matrix group extender to extend the first group of unitary matrices to generate a second group of unitary matrices; and a matrix group selector to select a group of columns corresponding to a communication rank from each of the unitary matrices that are elements of the second group so that the columns are optimized based on a distance between the columns corresponding to the communication rank.