Abstract: A video coding system is capable of encoding and/or decoding a video frame based on at least two different types of motion vector predictions. In one type, the motion vector predictor of a current block in the video frame is calculated using only the motion vector of a neighboring block which is directly above the current block. In another type, the motion vector predictor is calculated using the motion vector of a neighboring block which is located on the left side of the current block. In the former type, adjacent blocks located in the same row can be decoded independently of each other. In the latter type, adjacent blocks located in the same column can be decoded independently. The system may also be capable of conventional coding. An indication is used for indicating to the decoder side which type of motion vector predictor is used in the encoding.

Abstract: A method for estimating a motion vector is provided. The method is for estimating a motion vector for a current block with reference to a number of candidate blocks in a reference frame. The method includes the steps of: firstly, determine an error between the current block and each candidate blocks according to an error function. The error function combining a DC difference and a couple of AC differences between the current block and each candidate blocks. Then, determine the candidate block having the lowest error as a matching block of the current block. Next, determine the motion vector for the current block based on a displacement between the current block and the matching block.

Abstract: A video decoding device includes: a decoder that decodes an encoded video bit stream to generate a prediction error signal; a motion compensator that performs a motion compensation prediction using a motion vector that refers at least one picture to generate a motion compensation prediction signal; a weighted predictor that generates a weighted prediction signal from a linear sum of (1) a product of the motion compensation prediction signal and a first weighting coefficient and (2) a second weighting coefficient; a selector that selects one of the motion compensation prediction signal and the weighted prediction signal; and an adder that adds (1) selected one of the weighted prediction signal and the motion compensation prediction signal and (2) the prediction error signal.

Abstract: Provided are an image encoding/decoding method and apparatus, which assign a virtual motion vector to a block that is encoded in an intra prediction mode and generate a new prediction block that is a combination of a prediction block generated by motion compensation using the virtual motion vector and another prediction block generated by intra prediction.

Abstract: Provided are a video encoding and decoding method and apparatus, in which a current block is divided into partitions based on an edge in the current block, and motion estimation is performed on the divided partitions. Video encoding efficiency can be improved by encoding partitions that are obtained by dividing the current block along a predetermined line passing through pixels belonging to an edge around the current block from among neighboring pixels around the current block.

Abstract: Provided are a method of efficiently transmitting motion model parameters using temporal correlation between video frames and a video encoding and decoding method and apparatus, in which motion estimation and motion compensation are performed by generating a plurality of reference pictures that are motion-compensated using motion model parameters. Motion model parameters are encoded based on temporal correlation between motion vectors of representative points expressing the motion model parameters, global motion compensation is performed on a previous reference video frame using motion model parameters in order to generate a plurality of transformation reference pictures, and a current video frame is encoded using the plurality of transformation reference pictures.

Abstract: A method and apparatus for encoding a skip macroblock by dividing the skip macroblock into smaller skip sub blocks and using predictive motion vectors predicted from motion vectors of blocks adjacent to the skip sub blocks, and a method and apparatus for decoding the skip macroblock is provided. Accordingly, by adding predetermined binary information indicating whether the skip macroblock is divided to the skip macroblock that generally transmits only prediction mode information, division of the skip macroblock can be adaptively applied, or all skip macroblocks can be divided into sub-blocks to be processed, so that pixel values in the skip macroblock can be predicted by using motion vectors of spatially adjacent blocks. Therefore, prediction efficiency increases.

Abstract: A video compressor has a real-time compression with a constant frame rate. The complexity in the compression of each frame is controlled to be smaller than a maximum value according to power management or compression time requirement. Delay jitter is eliminated. The present invention can be applied to MPEG-like video coding systems, such as H.264, MPEG4 and H.263.

Abstract: Quality settings established by an encoder are adjusted based on information associated with regions of interest (“ROIs”). For example, quantization step sizes can be reduced (to improve quality) or increased (to reduce bit rate). ROIs can be identified and quality settings can be adjusted based on input received from a user interface. An overlap setting can be determined for a portion of a picture that corresponds to an ROI overlap area. For example, an overlap setting is chosen from step sizes corresponding to a first overlapping ROI and a second overlapping ROI, or from relative reductions in step size corresponding to the first ROI and the second ROI. ROIs can be parameterized by information (e.g., using data structures) that indicates spatial dimensions of the ROIs and quality adjustment information (e.g., dead zone information, step size information, and quantization mode information).

Abstract: The disclosure relates to a method of coding at least one still or animated image, in which said image is associated with (i) a basic mesh formed by a set of faces that are defined by a set of vertices and edges and (ii) coefficients in a base of wavelets corresponding to local modifications to the basic mesh, known as wavelet coefficients, wherein the coded data rate is controlled. The method includes the following steps: controlling a first rate of data representative of a basic mesh that meets a first rate criterion; controlling a second rate of data representative of wavelet coefficients according to a second rate criterion; and finally optimizing the coded data rate by controlling the quantification characteristics of the selected wavelet coefficients.

Abstract: A method of simplifying deblock filtering of video blocks of an enhanced layer of scalable video information is disclosed which includes selecting an adjacent pair of video blocks, determining whether boundary strength of the video blocks is a first value, evaluating first conditions using component values of a first component line if the boundary strength is not the first value, and bypassing deblock filtering between the video blocks if the boundary strength is the first value or if any of the first conditions is false. The method may include bypassing evaluating conditions and deblock filtering associated with the maximum boundary strength. The method may include bypassing evaluating second conditions and bypassing corresponding deblock filtering if the intermediate edge is a horizontal edge. The method may include bypassing less efficient memory reads associated with component values used for evaluating the second conditions.

Abstract: A system for processing sub-blocks of a macroblock of a video frame. In an example embodiment, the system includes a first module that is adapted to process each sub-block of the macroblock, wherein each sub-block is associated with a predetermined position in a first sequence. The processing of certain sub-blocks in the first sequence requires results of processing of one or more previously processed sub-blocks in the first sequence. A controller selectively enables the first module to process each sub-block of a second sequence that is altered from the first sequence so that the first module implements parallel or pipelined processing of certain sub-blocks of the macroblock. In a more specific embodiment each sub-block in the first sequence of sub-blocks is consecutively numbered 0-15 according to H.264 standards.

Abstract: A video processing system. In a specific embodiment, the system implements a system for processing macroblocks that includes a first module for processing a macroblock. A controller provides a first macroblock to the first module and provides a second macroblock to the first module, without waiting for the first module to complete processing of the first macroblock, when information is available to the first module to process the second macroblock. The first module may implement a pipelined processor that is adapted to process macroblocks simultaneously. Alternatively, the first module includes a first engine and a second engine, which may run in parallel as parallel engines. In a more specific embodiment, an entire image frame is treated as a single slice and processed by the system via a pipelined engines or parallel engines.

Abstract: A moving picture communication device and a gateway capable of suppressing or limiting image quality deterioration as well as a moving picture communication system including them are provided. Control information 141 is transmitted from a moving picture reception/decoding device 2 to a moving picture encoding/transmission device 3 at a predetermined time interval. The moving picture encoding/transmission device 3 performs encoding in the intra-frame encoding mode according to the control information 141, thereby suppressing the propagation of image deterioration caused by a transmission error to a subsequent frame and performs image refresh operations at a predetermined interval. The moving picture encoding/transmission device 3 performs the image refresh operation at a predetermined interval so as to recover from image deterioration when the control information 141 is received even if erroneous recognition has occurred, i.e.

Abstract: Provided is a method and apparatus for displaying video data without a display delay. In the method, a code indicating an end of stream is appended so that the code is appended behind a last video stream included in a stream to be displayed when only a part of an input stream including one or more video streams is displayed. In addition, the last video stream is displayed which is appended with the code indicating an end of stream.

Abstract: Techniques and tools are described for using quantization bias that accounts for relations between transform bins and quantization bins. The techniques and tools can be used to compensate for mismatch between transform bin boundaries and quantization bin boundaries during quantization. For example, in some embodiments, when a video encoder quantizes the DC coefficients of DC-only blocks, the encoder compensates for mismatches between transform bin boundaries and quantization bin boundaries. In some implementations, the mismatch compensation uses an offset table that accounts for the mismatches. In other embodiments, the encoder uses adjustable thresholds to control quantization bias.

Abstract: A system and method of generating an output signal includes a receiving system generating a plurality of signals having a first format, an encoder 162 encoding the plurality of signals into a plurality of transport streams and a multiplexer 210. The system also includes a local area network 130 routing the plurality of transport streams to the multiplexer 210 to form a combined signal, a modulator 214 modulating the combined signal to form a modulated signal and a system 202 forming the output signal from the modulated signal. In one aspect, the output signals may be satellite uplink signals.

Abstract: An analog/digital gain control device avoid some of the requirements associated with the nature of a closed-loop AGC circuits and which meets the remaining requirements without much difficulty uses an analog to digital conversion method that increases the number of effective ADC bits by compressing the baseband input analog signal using a logarithmic circuit. After the compressed analog signal is converted into a digital signal, a digital anti-log process or look-up table (LUT) is used to expand the digital signal back to the original linear scale. The word size of the output of the anti-log process is larger than the input word size due to the nature of the anti-log function. To reduce the word size of the digital signal an open loop normalization technique can be applied.

Abstract: A method and system for predicting channel fading, particularly in a mobile wireless environment, that is accurate for long-range predictions. The method comprises estimating a model parameters based on a current channel estimate, and recursively adapting the model parameters to predict future channel fading coefficients until a predetermined re-acquisition condition is satisfied. Once the re-acquisition condition has been satisfied, the model parameters are again estimated based on a current channel estimate. The acquired model parameters are adaptively updated and used in a Kalman filter.

Abstract: The present invention is directed to a system and method for channel estimation for a communication channel such as, for example, that found in a wireless communication network. One or more channel estimates or channel observables can be combined to compute a refined channel estimate, for example, when the channel estimates or channel observables are from the same channel.

Abstract: Systems and methods which introduce a variable shift with respect to pilot symbols in providing a data subcarrier channel estimation are shown. Use of pilot symbol shifts may be useful, for example, when path delay is long and/or when non-consecutive, non-uniformly distributed pilot subcarriers are used. The foregoing shift may be introduced in the time or frequency domains according to embodiments of the invention. For example, a shift of a particular number of samples may be introduced with respect to the symbols of the pilot subcarriers in the measured pilot subcarrier channel response for use in data subcarrier channel estimation.

Abstract: Systems and methods which are adapted determine timing with respect to an orthogonal frequency division (OFD) channel, such as may be used with respect to an OFDM or OFDMA systems through reliably identifying timing of a first arriving signal path. Embodiments use deconvolution to construct the channel impulse response associated with a received signal. The first arriving path for the received signal may readily and reliably be determined using the channel impulse response information.

Abstract: A system and method of transmitting and processing pilot signals includes decorrelating a pilot tone that conveys a pilot signal, performing a channel estimation based on the decorrelated pilot tone to calculate estimated channel values and positioning the estimated channel values consistent with their order in subsequent transmission units. In one embodiment, the decorrelation comprises an interleaving operation. In another embodiment, the decorrelation occurs during a channel estimation stage. The decorrelation can be performed during a channel estimation stage by interleaving and deinterleaving pilot signals in the receiver.

Abstract: A method for an operating system including a channel estimation for OFDM systems in a receiver is disclosed. One embodiment provides information indicative of multiple transmitter signals reception characteristics of signals received from multiple transmitters. Then, channel estimation is performed dependent on the information.

Abstract: In one embodiment of the present disclosure, a method for improving communication between a transmitter and a receiver is disclosed. The method can include receiving a first signal having a first power level over a first path, receiving a second signal having a second power level over a second path wherein the first path is different than the second path. The method can compare the first power level with the second power and determine a difference between the first power level and the second power level. The method can also adjusting a parameter in the system to reduce the difference in power levels between the first and second signals compensating for interference cause by many sources.

Abstract: A multiuser scheme allowing for a number of users, sets of user, or carriers to share one or more channels is provided. In the invention, the available channel bandwidth is subdivided into a number of equal-bandwidth subchannels according to standard OFDM practice. A transmitter transmits data on a set of OFDM subchannels that need not be contiguous in the spectrum or belong to the same OFDM channel. A receiver receives and decodes the data and detects errors on subchannels. The receiver then broadcasts the identity of those subchannels on which the error rate exceeds a specific threshold, and the transmitter may select different subchannels for transmission based on this information.

Abstract: Disclosed is a data transmission/reception method and system for minimizing intercarrier interference (ICI) in a communication system using a multicarrier. The data transmission method by a transmitter includes grouping transmission signals in units of a predetermined number of transmission signals when the transmitter has received the transmission signals, multiplying each group of the transmission signals by a transmission coding matrix, and transmitting the transmission signals multiplied by the transmission coding matrix to a receiver.

Abstract: An approach is provided for performing control signaling. Data and control information are received. The control information is orthogonalized using block-level spreading. The data and the orthogonalized control information are multiplexed at a symbol-level.

Abstract: The present invention relates to a method of generating a signal for transmission over a channel subject to transmission conditions. A corresponding signal and a method of receiving a signal over a channel subject to transmission conditions are also disclosed. The invention further relates to a transmitter and a receiver.

Abstract: The method is for managing the operation of a wireless communication device including several different communication modules respectively adapted to operate according to several given communication protocols including a UWB module operating according to a UWB protocol based on an OFDM modulation scheme. The method includes controlling the UWB module for scanning a chosen frequency band, and managing a communication to be performed by the device on the basis of the scanning result.

Abstract: Embodiments achieve favorable performance-complexity trade-offs in MIMO detection for three or more channel inputs. Some embodiments describe systems and methods comprising a leaf node predictor for receiving a processed communications stream, determining at least one channel metric corresponding to the communications stream for a given channel realization, and generating at least three instructions to output, which at least one instruction corresponds to at least one predicted best leaf node candidate for the given channel realization. Further embodiments alternatively describe systems and methods which enumerate N1 best values of a first symbol, enumerate N2 (i) best values of a second symbol for an i-th best value of the first symbol, enumerate N3 (i, j) best values of a third symbol for an i-th best value of the first symbol and j-th best value of the second symbol, combine enumerated best values of each symbol into a leaf-node value, and compute the cost of each leaf-node value enumerated.

Abstract: A radio transmitting apparatus includes an attacher to attach an error-detecting bit to a bit sequence, a coder to perform systematic coding on a bit sequence to which the error-detecting bit is attached to generate an information bit sequence and a parity bit sequence, a first modulator to modulate the information bit sequence to generate a first modulation symbol, a second modulator to modulate the parity bit sequence to generate a second modulation symbol, an allocator to allocate the first modulation symbols to first subcarriers by dispersing the first modulation symbols in the frequency/time direction, and allocate the second modulation symbols to second subcarriers different from the first subcarriers, an modulator to perform OFDM modulation on the first and second modulation symbols by using the first and the second subcarriers to generate an OFDM signal, and a transmitting unit to transmit the OFDM signal.

Abstract: A transmission apparatus in a Multiple Input Multiple Output (MIMO)-based wireless communication system. The transmission apparatus includes at least two antenna groups each having at least two antennas, wherein the antenna groups are spaced apart by a first distance and transmit antennas in each antenna group are spaced apart by a second distance which is shorter than the first distance. A channel coding and modulation unit channel-codes and modulates a desired transmission data stream. A precoding unit precodes the channel-coded and modulated signal separately for each antenna group and each antenna in the same antenna group. Thereafter, a transmission processing unit transmission-processes the output signal from the precoding unit.

Abstract: Techniques for bandwidth allocation in communication systems such as OFDM, OFDMA, or SC-FDMA systems to improve spectral efficiency and increase flexibility and adaptability with scalable single or multiple-carrier bandwidth allocation characteristics.

Abstract: The present invention relates to a multi-input multi-output (MIMO) system for enhancing transmission performance. The MIMO system uses space-time encoding and transmit antenna selection methods, and includes a transmitter (100) and a receiver (200). The transmitter (100) includes N transmit antennas (130-1, 130-4) that are more than M tansrni antennas (130-1, 130-3) used for transmitting a signal to space channel, selects the M transmit antennas (130-1, 130-3) among the N transmit antennas (130-3 130-4), and transmits symbol by space-time encoding the symbol. The receiver (200) includes M receive antenna (120-1, 210-2) for receiving a signal from the space channel, detects an information symbol by using the signal received through the receive antenna (210-1, 210-2), generates transmit antenna selection information for selecting M transmit antennas (130-1, 130-3) among transmit antennas (i30-1, . . . 7130-4) with reference to a channel estimate, and returns the information to the transmitter.

Abstract: A method and a system for reducing computational complexity in a maximum-likelihood MIMO decoder, while maintaining its high performance. A factorization operation is applied on the channel Matrix H. The decomposition creates two matrixes: an upper triangular with only real-numbers on the diagonal and a unitary matrix. The decomposition simplifies the representation of the distance calculation needed for constellation points search. An exhaustive search for all the points in the constellation for two spatial streams t(1), t(2) is performed, searching all possible transmit points of (t2), wherein each point generates a SISO slicing problem in terms of transmit points of (t1); Then, decomposing x,y components of t(1), thus turning a two-dimensional problem into two one-dimensional problems. Finally searching the remaining points of t(1) and using Gray coding in the constellation points arrangement and the symmetry deriving from it to further reduce the number of constellation points that have to be searched.

Abstract: Joint decoding of ISI (Inter-Symbol Interference) channel and modulation codes. A means is presented by which a single, combined ISI and modulation decoding module is operable to process a signal received from an ISI communication channel and directly to generate a soft estimate of information encoded therein. A single module, that employs a decoding transfer function that is substantially matched to the communication channel that introduces the ISI and the modulation encoding performed on the information before being launched into the ISI communication channel. This means is adaptable to a variety of modulation coding systems that are tailored to deal with communication systems that introduce ISI. Moreover, this means is extendable to communication systems employing an error correction code (ECC) such as Reed-Solomon (RS) coding as well as ECCs of an iterative nature such as LDPC (Low Density Parity Check) coding, turbo coding, and/or turbo trellis code modulation (TTCM) coding.

Abstract: The invention concerns a method and device for operating MIMO air interfaces in mobile communications systems, according to which a radio signal is transmitted by a transmitting device via an MIMO channel comprising a number of m subchannels and is received by a receiving device having n antennas. The invention is based on the fact that different polarizations are assigned to the signals to be transmitted on the subchannels, and the signals are supplied to a common antenna.

Abstract: A method and system to switch among a plurality of antennae used for wireless communications. A first embodiment is a method for using at least one quality metric and at least one time variation indicator of at least one quality metric to selectively switch among a plurality of antennae to maintain wireless communications. A second embodiment is a method using at least one quality metric and at least one time derivative slope of at least one quality metric to selectively switch among a plurality of antennae to maintain wireless communications. These embodiments can be applied in several wireless communication applications using multiple antennae including, but not limited to, WiMAX applications.

Abstract: A method for a wireless communication system is provided. The method includes analyzing a set of signal sources that are operably associated with a set of time domain windows. Often, the method periodically switches the association between the set of time domain windows and the set of signal sources in order to facilitate a determination of one or more signal paths generated by the signal sources.

Abstract: An apparatus (100) and method (200) for detecting the presence of abrupt noise is provided. The method can include estimating (210) a subband energy of the signal, calculating (220) a peak-to-peak energy difference (345), and calculating (230) a spectrum deviation (426). A request to update a noise channel estimate can be declared if a) a total estimated channel energy is greater than a predetermined noise floor (442), and b) the spectrum deviation is less than a predetermined variance threshold (444), and c) the peak-to-peak energy difference is less than a predetermined peak-to-peak threshold (446), or d) if a voice metric is less than a voice level threshold (448).

Abstract: The present embodiments provide methods, systems and apparatuses that facilitate communication between two or more devices. Some of these methods identify a first communication to be transmitted and generate a first plurality of frames such that bit data of each of the frames of the first plurality of frames is different than the bit data of each of the other frames of the first plurality of frames, and that a first frame of the first plurality of frames include at least a first portion of the first communication. The first plurality of frames can then be transmitted.

Abstract: The present invention is directed to a system and method which allows for power amplification of an input signal using power amplification combined by changing the center frequency with an up-converter to shift a baseband signal to a signal at a carrier frequency in the same process. This then provides a digital implementation that is power efficient and has little or no linearity issue-technology suitable for a silicon chip and broadband operation. In one embodiment, each input sample is replaced with a number of sub-samples within the same sample interval, the total weight of the sub-samples being equal to the replaced sample. This sample to sub-samples process alters the frequency response of the sampled signal and reduces the amplitude dynamic range of the load driver, thereby simplifying the filter requirements for digital to analog conversion while reducing linearity requirement of the load driver. This process can be implemented by digital circuits which results in broadband operation.

Abstract: A sequence generation method for allowing a reception end to effectively detect a sequence used for a specific channel of an OFDM communication system, and a signal transmission/reception method using the same are disclosed. During the sequence generation, an index is selected from among the index set having the conjugate symmetry property between indexes, and a specific part corresponding to the frequency “0” is omitted from a transmitted signal. In addition, a reception end can calculate a cross-correlation value between a received (Rx) signal and each sequence using only one cross-correlation calculation based on the conjugate symmetry property.

Abstract: The invention discloses a signal transmission system, method and apparatus, and relates to the fields of communications and broadcast television. It is intended to reduce the hardware cost of the signal transmitting system. The system according to the invention is based on a personal computer operating system, and comprises a computer and a transmitting equipment, said computer comprising a signal source processing module for processing a signal source, a channel encoding and modulating module for channel encoding and modulating of the processed signal source, and an interface module for outputting the data encoded and modulated by the channel encoding and modulating module, and said transmitting equipment being arranged to receive data from the interface module, process the received data into a radio frequency RF signal, and then transmit the RF signal. The invention may be applicable to a transmitter of broadcast television.

Abstract: A transmitter capable of suppressing a peak of a transmission signal includes a frequency domain acquisition unit for obtaining a frequency domain signal from the signal for transmission; and a level control unit for controlling a level of the frequency domain signal obtained by the frequency domain acquisition unit to suppress a peak in a time domain transmission signal. Further, the transmitter includes a time domain conversion unit for converting the frequency domain signal into the time domain transmission signal whose level has been controlled by the level control unit; and a transmission unit for transmitting the time domain transmission signal.

Abstract: To provide a signal transmitting/receiving apparatus etc. where a cable length can be measured by using a general-purpose cable, without using an interface. A differential transmission circuit by the present invention includes a signal output circuit sending a high-speed differential signal and a pulse wave; a signal input circuit including a terminating resistor; a bias controller controlling a bias voltage on a transmission path; a terminating resistance controller disconnecting the terminating resistor on sensing a bias voltage and connecting it on sensing no bias voltage, by a bias sensing circuit; a sensing input circuit sensing a pulse wave reflected at the signal input circuit; and an output setting controller setting an electric characteristic of a signal outputted from the signal output circuit by a propagation time from sending the pulse wave by the signal output circuit to receiving the reflected pulse wave by the sensing input circuit.

Abstract: In a digital communication system such as a mobile radio system, fading distortion is compensated with a raised precision. In a transmitter, pilot signals are regularly inserted in the information signals. The amplitude of the pilot signals are set larger than the maximum possible amplitude of the information signals. The modulation scheme of the pilot signals may be different from that of the information signals. In a receiver, the fading distortion of each of the pilot signals is determined. The fading distortions of the information signals are estimated by interpolation using the determined fading distortion of the pilot signal, and then compensated. The frequency band of each information signal is preferably limited with a roll-off filter with a roll-off coefficient ranging from 0.1 to 0.4.

Abstract: Method and device for transmitting outgoing useful signals and an outgoing clock signal. Useful signals and a clock signal are transmitted from a transmitter via a first line pair and a second line pair to a receiver. A first useful signal is transmitted in the form of a modulated difference between the electrical potentials of the first line pair. A second useful signal is transmitted in the form of a modulated difference between the electrical potentials of the second line pair. The clock signal is transmitted in the form of a modulated difference between the average value of the potentials of the first line pair and the average value of the potentials of the second line pair.

Abstract: A pre-emphasis automatic adjusting system is provided which is capable of placing the best suitable emphasis against attenuation occurring in a through hole. A step signal is transmitted from a transmitting circuit via a signal transmission path to a receiving circuit with termination of the receiving circuit being released. A voltage of its reflected signal is compared with a first reference voltage of a first reference voltage source. Based on a comparison result in a capacitive reflection section in which a voltage of the reflected signal is less than the first reference voltage, a section detecting signal is outputted from a reflected wave detecting circuit.