Abstract: In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, first data and second data that correspond to a unit of audio, video, and/or image information is received. The first data and the second data are encoded and modulated so that a resulting data rate of the first data is less than a resulting data rate of the second data. The first data and the second data are parsed to a plurality of spatial streams, and a single PHY data unit that includes the plurality of spatial streams is generated.

Abstract: Disclosed are a method and a apparatus for encoding a video, and a method and apparatus for decoding a video, in which neighboring pixels used to perform intra prediction on a current block to be encoded are filtered and intra prediction is performed by using the filtered neighboring pixels.

Abstract: Disclosed herein is a method for decoding a video signal having at least one frame with a plurality of blocks including a current block, including generating, for at least a selected pixel in the current block, a predicted value for at least one pixel located in a row i and a column j of the current block using a processor and according to the following equation: Xij=Li+Aj?C; wherein Xij is the predicted value, Li is the value of a pixel to the left of the current block, Aj is the value of a pixel in a row above the current block and C is the value of a pixel in the row above and the column to the left of the current block and decoding the current block using the predicted value.

Abstract: Embodiments of an apparatus and method for decoding an encoded bitstream to generate a video signal are taught. A decoder receives the bitstream and decodes a portion thereof to obtain at least a portion of a predictive reference frame. The reference frame is generated by, for example, selecting a filter set including a target frame with a block having a plurality of pixels and at least one adjacent frame, determining a coding mode associated with the block, determining a block-specific factor derived from the coding mode, determining weighted averages of pixels in the filter set and using the weighted averages to generate the predictive reference frame. The decoder also generates a residual from another portion of the encoded bitstream that represents a portion of a frame of the plurality of frames and reconstructs the portion of the frame by adding the residual to the predictive reference frame.

Abstract: The transmitting end of a content distribution system selectively employs a redundancy mechanism to encoded video data based on the frame type of each frame being transmitted. In the event that a particular frame contains information upon which the decoding of multiple frames may depend, the transmitting end can apply a redundancy mechanism to redundantly distribute the data of the frame throughout a set of data segments, each of which is separately transmitted via the network to the receiving end. Otherwise, in the event that a particular frame to be transmitted does not contain substantial information upon which the decoding of multiple frames may depend, the loss of some or all of the data of the frame may not appreciably affect the presentation of the video content at the receiving end and thus the transmitting end can forgo application of the redundancy mechanism to such frames so as to avoid unnecessarily processing and reduce the overall network bandwidth used to transmit the encoded video data.

Abstract: Methods and systems for processing B pictures with missing or invalid forward reference pictures are disclosed. Aspects of one method may include decoding of a contiguous sequence of B pictures that immediately follow a first I picture after a sequence header. The decoding of the B pictures may handle video edit codes in the AVS1-P2 format and/or random access points. Some embodiments of the invention may discard B pictures that refer to invalid or missing forward reference pictures, while other embodiments of the invention may interpolate B pictures. For an invalid forward reference picture, the interpolation algorithm for generating pictures may use the invalid forward reference picture and the backward reference picture. For a missing decoded forward reference picture, as in a random access, the interpolation algorithm for generating pictures may use the backward reference picture.

Abstract: The present invention relates to a method of storing pictures in a memory, a picture being divided into data blocks, said method comprising the step of: computing a transform of an input data block for producing a transformed data block comprising a set of n transformed elements, where n is an integer, entropy coding m first transformed elements of the transformed data block for producing an encoded data block, where m is an integer lower than n, computing a cost function on the basis of a weighted sum of a distortion value between the input data block and the encoded data block and a power consumption required for reading or writing the encoded data block in the memory, iterating the entropy coding and cost function computing steps for different values of m, and storing in the memory the encoded data block corresponding to the value of m that minimizes the cost function.

Abstract: When a prediction is made between fields with different parity, the predicative efficiency of a chrominance vector is improved by adaptively switching the generation of a chrominance motion vector depending on a encoding/decoding field parity (top/bottom) and a reference field parity (top/bottom), and the coding efficiency is improved accordingly.

Abstract: When a prediction is made between fields with different parity, the predicative efficiency of a chrominance vector is improved by adaptively switching the generation of a chrominance motion vector depending on a encoding/decoding field parity (top/bottom) and a reference field parity (top/bottom), and the coding efficiency is improved accordingly.

Abstract: A video encoding method and apparatus are provided. The video encoding method includes determining whether a current block includes an affine-transformation object having an affine transformation; if the current block includes an affine-transformation object, generating a prediction block by performing affine transformation-based motion compensation on the current block in consideration of an affine transformation of the affine-transformation object; and if the current block does not include any affine-transformation object, generating a prediction block by performing motion vector-based motion compensation on the current block using a motion vector of the current block. Therefore, it is possible to achieve high video encoding/decoding efficiency even when a block to be encoded or decoded includes an affine transformation.

Abstract: A video block syntax element indicates whether all of the partitions of a video block are predicted based on a same reference list and no greater than quarter-pixel accuracy is used. If the video block syntax element is set, partition-level signaling of the reference lists is avoided. If the video block syntax element is not set, partition-level signaling of the reference lists occurs. If the video block syntax element is set, partition-level syntax elements may be used for each of the partitions of the video block, wherein the partition-level syntax elements each identify one of the reference lists and motion vector accuracy for a given one of the partitions.

Abstract: A video codec having a modular structure for encoding/decoding a digitized sequence of video frames in a multi-core system is described. The video codec comprises a memory unit; a multithreading engine. and a plurality of control and task modules organized in a tree structure, each module corresponding to a coding operation. The modules communicate with each other by control messages and shared memory. The control modules control all coding logic and workflow, and lower level task modules perform tasks and provide calculations upon receiving messages from the control task modules. The multithreading engine maintains context of each task and assigns at least one core to each task for execution. The method of coding/decoding comprises an error resilient algorithm.

Abstract: A coding apparatus includes a motion vector coding unit that codes an inputted motion vector. A motion vector for each current block is coded based on a difference between the motion vector and a predicted vector obtained from motion vectors of coded neighboring blocks. The predicted vector is generated by one of the following methods: motion vectors referring to the same picture are selected from among the motion vectors for the neighboring blocks; motion vectors of respective neighboring blocks are ordered in a, predetermined order, and the motion vectors of the same order rank are selected from the ordered motion vectors; and the predicted vector of a second motion vector of the current block is the first motion vector, and if the second motion vector and the first motion vector refer to different pictures, the first motion vector is scaled according to the temporal distance between the pictures.

Abstract: A method of operating a digital television decoder is disclosed. The decoder includes a memory, the memory storing onboard software, and the decoder is operable in a run mode to execute the onboard software. The method comprises: activating a power saving mode on the decoder; and upon activating the power saving mode: maintaining power to the memory; suspending execution of the onboard software; acquiring an execution context of the onboard software; updating the execution context of the onboard software to form an updated execution context; and saving the updated execution context in the memory.

Abstract: A communication terminal, includes: a communicator, configured to transmit and receive data to and from a server storing video contents; an accumulator, configured to accumulate a plurality of partial streams extracted from different time positions within the video contents received through the communicator as asynchronous streams; a decoder, configured to decode at least one of the asynchronous streams and synchronous streams that are not extracted as the asynchronous streams from the video contents, the synchronous streams being streaming-distributed from the server; and a controller, configured to acquire streams having time position information before and after a reproduction time position of the at least one of the asynchronous streams and the synchronous streams decoded by the decoder while the at least one of the asynchronous streams and the synchronous streams are reproduced on the display, and control the display to display the acquired streams after the reproduction.

Abstract: This disclosure describes video encoding and decoding techniques in which a first order prediction process and a second order prediction process are used in combination to generate predictive video blocks for video coding. First order prediction may be similar to conventional motion estimation and motion compensation that generates residual video blocks. The second order prediction may involve a process similar to conventional intra-prediction, but is performed on the residual video blocks. The techniques of this disclosure may pre-define the second order prediction to a specific mode, such as a mode similar to the intra-DC mode used in intra coding. In addition, the techniques of this disclosure may combine aspects of the first order and second order prediction into a single process so that the effects of second order prediction on the residuals are taken into account during the first order prediction process, which may improve compression.

Abstract: A quantizer and dequantizer for use in a video coding system that applies non linear, piece-wise linear scaling functions to video information signals based on a value of a variable quantization parameter. The quantizer and dequantizer apply different non linear, piece-wise linear scaling functions to a DC luminance signal, a DC chrominance signal and an AC chrominance signal. A code for reporting updates of the value of the quantization parameter is interpreted to require larger changes when the quantization parameter initially is large and smaller changes when the quantization parameter initially is small.

Abstract: The present invention realizes a video coding apparatus that is simple in configuration and can avoid video display quality deterioration due to an overrun of video coding processing.

Abstract: A method and a system for bit reorganization and packetization of uncompressed video for transmission over wireless communication channels. The bit stream of the uncompressed video is reorganized according to importance levels of video bits. Then, various unequal protection methods such as encoding are applied to bits at different video importance levels. The reorganized and encoded information is then transmitted from a transmitter to a receiver over a wireless channel. The receiver performs the reverse steps of the transmitter, along with error detection/correction as needed, to recover the uncompressed video information.

Abstract: Disclosed are various embodiments of three-dimensional (3D) video coding using scalable video coding (SVC) spatial scalability. In one embodiment, 3D video is encoded to generate a SVC base layer that includes a left first-resolution view and a right first-resolution view packed in a first frame. 3D video is encoded to generate a SVC enhancement layer that includes a left second-resolution view and a right second-resolution view packed in a second frame. The left second-resolution view and the right second-resolution view may have a higher spatial resolution than the left first-resolution view and the right first-resolution view.

Abstract: A system and method are used to generate pseudo MPEG information from digital video information. An artificial time stamp module and a data transport device can be used to generate the pseudo MPEG information, including associating an artificial time stamp with the digital video information. This pseudo MPEG information can be decoded as MPEG information.

Abstract: Method and arrangement for use in a receiving node, for determining whether received data is encoded with a certain channel code candidate. The method involves obtaining baseband data encoded with an unknown channel code and calculating the respective posterior probabilities that a set of syndrome checks are satisfied, given the obtained data, which syndrome checks are associated with the channel code candidate. The method further involves combining the posterior probabilities and determining whether the channel code candidate was used for encoding the obtained data, based on the combined posterior probabilities.

Abstract: An apparatus and method for channel estimation comprising obtaining a response matrix G(l) using Q quantity pilots; constructing a sensing matrix Wsensing based on K quantity tones, L quantity symbols and P quantity multipaths; and using compressive sensing channel estimation to determine an equivalent channel matrix Gp(i) based on the response matrix G(l) and the sensing matrix Wsensing.

Abstract: A method and apparatus for transmitting Channel State Information Reference Symbol (CSI-RS) and data with partial muting of the CSI-RS are proposed. The method includes determining a CSI-RS pattern to be used among CSI-RS pattern candidates, determining a muting pattern for muting some resource elements constituting CSI-RS pattern candidates except for the determined CSI-RS pattern, mapping data symbols and CSI-RS to resource elements in a resource grid with rate patching in consideration of the CSI-RS pattern and muting pattern, and transmitting the data symbols and CSI-RS to a terminal.

Abstract: A technique for removing a band-limited distributed pilot signal from an orthogonal frequency division multiplexed (OFDM) signal involves converting a received OFDM signal, which includes a distributed pilot signal and an OFDM data signal, into a frequency domain signal having populated frequency bins containing respective subcarrier signals, each including a constituent data signal of the OFDM data signal and component pilot signal of the distributed pilot signal. An average magnitude of the populated frequency bins is determined based on the absolute values of the complex components of the populated frequency bins of the frequency domain signal, and the average magnitude of the populated frequency bins is used to estimate a pilot signal magnitude. The distributed pilot signal is removed from the frequency domain signal using a stored replica of the pilot signal scaled in conjunction with the pilot signal magnitude to yield the OFDM data signal.

Abstract: In a method for detecting a clock rate of a data unit, the data unit is received via a communication channel. The data unit includes i) a first preamble portion and ii) an orthogonal frequency division multiplexing (OFDM) portion following the first preamble portion. The OFDM portion includes a second preamble portion including one or more long training fields. Based on the first preamble portion, whether a clock rate of the OFDM portion is a first clock rate or a second clock rate lower than the first clock rate is determined based on the first preamble portion.

Abstract: Disclosed is a method for receiving data in a Multi Input Multi Output (MIMO) system, the method comprising: decoding data transmitted from a transmitter by using one beam-forming vector included in a codebook that beam-forming vectors are formed in a hierarchical structure according to at least one of change directions of radio channels, the number of channel change directions, and a change rate; determining whether to update the beam-forming vector based on the radio channel changes; selecting other beam-forming vector included in the codebook having a hierarchical structure when it is determined that update for the beam-forming vector is required; feed-backing information about an index indicating where the selected beam-forming vector is located in the hierarchical structure of the codebook to the transmitter; and decoding data received from the transmitter by using the selected beam-forming vector.

Abstract: An Orthogonal Frequency Division Multiplexing (OFDM) receiver system for improved pilotless detection of symbol boundary of a received OFDM symbols using M-ary Phase Shift Keying (M-PSK) modulated carriers as a cost function. The OFDM receiver includes a symbol boundary detection block that detects a symbol boundary of the received OFDM symbols. The symbol boundary detection block detects the symbol boundary by computing a cost function of a second order moment of the M-PSK modulated carriers. The receiver system detects the symbol boundary for unknown information on the received OFDM symbols.

Abstract: A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation.

Abstract: A wireless communication apparatus prevents deterioration of communication characteristics because of a transmission weight of a highest common factor and enhances the communication characteristics of feedback MIMO.

Abstract: A CSI vector quantizer (VQ) system is provided for time-correlated channels. The VQ system operates a receiver forwarding quantized channel state information in the form of indices and a transmitter predicting channel state change. The VQ system is aimed at feedback channels, in which bit errors, erasures and delays can occur. The VQ system uses transmitter-side channel prediction algorithms that work with the quantized CSI information and allow the system to recover from feedback channel transmission errors, erasures and delays. Moreover, the techniques can be used to lower the required feedback rate, while keeping the system's throughput at the required level.

Abstract: The present invention provides an antenna diversity apparatus and an antenna diversity method. The antenna diversity apparatus comprises: a plurality groups of antennas, a switching unit, a demodulating unit, an antenna switch selecting unit, and a control unit, wherein each group of the plurality groups of antennas comprises at least an antenna, and the control unit can comprises: a receiving signal quality detecting unit, a packet detecting unit, and an antenna decision unit. The antenna decision unit can be realized by hardware, firmware, or software, and the antenna switch selecting unit can be realized by hardware. The antenna diversity apparatus and the antenna diversity method provided by the present invention can switch antennas fast to avoid the defect of occurring burst error to reduce transmitting data rate, and switch to proper antennas fast when variation of the data transmission channels occurs.

Abstract: Briefly, in accordance with one or more embodiments, in response to receiving a wireless communication signal, a non-uniform codebook is generated based at least in part on one or more characteristics of the received wireless communication signal for quantization and communication back to a source of the received signal. The non-uniform codebook may be generated by selecting a suitable uniform codebook based at least in part on the one or more characteristics of the received wireless communication signal, and supplementing the uniform codebook with additional codewords to generate the non-uniform codebook.

Abstract: A wireless communication system uses a multiple-input multiple-output (MIMO) antenna in the transceiver mode. The system includes the technical features of a stage in which m bits of a first set of information is transmitted for a first pre-coding matrix (where m is an integer greater than 1), and a stage in which n bits of a second set of information is transmitted for a second pre-coding matrix (where n is an integer greater than 1 but less than n).

Abstract: An apparatus for cooperative multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) is provided. The apparatus uses a new carrier assignment scheme (CAS) called generalized interleaved CAS, along with non-data-aided timing synchronization. With the generalized interleaved CAS, random OFDM signals are formed into patterns similar to unequal period synchronization patterns (UPSPs), and a corresponding non-data-aided timing synchronization scheme is set. With the help of majority vote refinement (MVR), the present invention achieves better timing synchronization and enhances the quality of signal demodulation.

Abstract: The present disclosure relates to channel state feedback in a communication system. The method includes obtaining a reference signal from an access point; deriving a rank indication, a codebook subset selection indication and a precoding matrix index based on the obtained reference signal; sending a first feedback message conveying the rank indication and the codebook subset selection indication, and sending a second feedback message conveying the precoding matrix index, to the access point; and receiving, from the access point, data precoded by a matrix derived based on the rank indication, the codebook subset selection indication and the precoding matrix index.

Abstract: A low level secondary communication signal is summed with an existing primary communication signal in a manner that prevents interference to the existing primary communication signal while providing secondary communication signal benefits such as increased data rate, range, or interference immunity. Examples are presented in which a M-QAM secondary signal is summed with either an ATC Mode S PPM reply or DPSK interrogation primary signal. Legacy Mode S transponders, TCAS, and ADS-B equipment continue to demodulate and decode the primary signal information in accordance with preexisting formats while new enhanced equipment obtains the benefits of the secondary signal.

Abstract: A method of operation of a communication system includes: calculating a shift distance of a received signal having a distortion; calculating an approximate likelihood of the received signal matching a transmitted signal from the shift distance; determining a bias factor from the distortion; and selecting a determined modulation maximizing a combination of the approximate likelihood and the bias factor for communicating with a device.

Abstract: The present invention relates to space-time or space-frequency coding in cellular systems. The same data is transmitted from different antennas with different coverage areas, corresponding to different cells. The different data streams have different parts of the space-time block codes applied. A mobile terminal can combine the different parts of the space-time block codes in different received signals. This provides better performance than the known techniques for single frequency networks. The invention can also be applied to antennas with different coverage areas from the same site, and different beams formed with antenna arrays.

Abstract: The present invention provides a device and method for realizing prefix code construction. The device includes a sort indexer, a generator and a sequence regulator. The sort indexer is used to sort a group of received code lengths to obtain a group of sorted code lengths, and record the position correspondence relationship. The generator receives the sorted code lengths and orderly generates the prefix codes. Except that the first prefix code is preconfigured, the generator generates a current prefix code by adding one to the adjacently previous prefix code and then shifting left by a certain number of bits. The sequence regulator is used to receive the prefix codes corresponding to the sorted code lengths, and regulates the sequence of the prefix codes corresponding to the sorted code lengths according to the position correspondence relationship recorded by the sort indexer to obtain the prefix codes corresponding to the code lengths.

Abstract: Disclosed are a phase shifter, a wireless communication apparatus, and a phase control method in which power consumption is reduced. A phase shifter includes a 90° step phase shifter (17) and a 45° phase shifter (18) and adds phase information to two baseband signals to be output to an orthogonal modulator. The 90° step phase shifter (17) contributes to adding any one of phases 0°, 90°, 180°, and 270° to the baseband signals according to a first control signal. The 45° phase shifter (18) contributes to adding one of phases 0° and 45° to the baseband signals according to a second control signal. A phase shifter (8) performs replacement of component signals of one of the baseband signals with component signals of the other of the baseband signals and inversion of polarities of the component signals.

Abstract: Method and apparatus for uplink transmission using multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) performs space time transmit diversity (STTD) encoding on an input stream of a physical channel configured for STTD. Each physical channel may be mapped to either an in-phase (I) branch or a quadrature-phase (Q) branch. The WTRU may perform the STTD encoding either in a binary domain or in a complex domain. Additionally, the WTRU may perform pre-coding on at least one physical channel including the E-DPDCH with the pre-coding weights, and transmitting the pre-coded output streams via a plurality of antennas. The pre-coding may be performed either after or before spreading operation.

Abstract: A communications device may include an In-phase (I) circuit having an In-phase modulator and mixer circuit, and an I power amplifier circuit coupled thereto, the I circuit configured to modulate and amplify a digital baseband I signal to generate an amplified I signal, and a Quadrature (Q) circuit having a Q modulator and mixer circuit, and a Q power amplifier circuit coupled thereto, the Q circuit configured to modulate and amplify a digital baseband Q signal to generate an amplified Q signal separate from the amplified I signal. A processor selectively switches the digital baseband I signal and the digital baseband Q signal between the I and Q signal inputs to provide selective phase shifting for the digital baseband I and Q signals.

Abstract: A transmitter may be operable to generate a sequence of symbols which may comprise information symbols and one or more pilot symbols. The transmitter may transmit the information symbols at a first power and transmit the one or more pilot symbols at a second power. In instances when a particular performance indicator is below a determined threshold, the first power may be set to a first value and the second power may be set to zero value. In instances when the particular performance indicator is above the determined threshold, the first power may be set to a second value and the second power may be set to a non-zero value. A value of the first power and a value of the second power may be based on an applicable average power limit determined by a communications standard with which the transmitter is to comply.

Abstract: Methods are disclosed for transmitting a plurality of information bits using resource selection on multiple antennas. In one or more embodiments, the methods include: selecting a first and a second orthogonal resource from an allocation of more than two orthogonal resources according to the state of the plurality of information bits; transmitting a first symbol in a first symbol instant on a first antenna using the first orthogonal resource; and transmitting a second symbol in the first symbol instant on a second antenna using the second orthogonal resource. In some embodiments, the first and second orthogonal resources are different and the first symbol is either a reference symbol or a modulation symbol.

Abstract: The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method for precoding data in a Multiple-Input Multiple-Output (MIMO) system. Embodiments of the invention disclose a secondary precoder 24 in series with a multiple-input multiple-output precoder 22. The secondary precoder 24 has a plurality of inputs 34, 36 and a plurality of outputs 38, 40. The second plurality of inputs being in communication with each plurality of outputs 38, 40 such that one or more signals input to a respective one or more of the second plurality of inputs 34, 36 provides a substantially equal power of signals at the second plurality of outputs 38, 40.

Abstract: There is provided a solution for dual channel transmission in a radio communication device. Both transmission signals to be transmitted on different channels are mixed two times by using oscillator signals having the same frequencies for both transmission signals, and the transmission circuitry is arranged to process the signals so that the transmission signals are nevertheless up-converted to different frequency channels.

Abstract: A configurable decoder within a receiver (for example, within a wireless communication device) includes numerous decoders. In one mode, the multiple decoders are used to decode different sub-packets of a packet. When one decoder completes decoding the last sub-packet assigned to it of the packet, then that decoder generates a packet done indication. A control circuit receives the packet done indications, and when all the decoders have generated packet done indications then the control circuit initiates an action. In one example, the action is the interrupting of a processor. The processor responds by reading status information from the control circuit, thereby resetting the interrupt. End-of-packet markers are usable to generate packet done indications and to generate EOP interrupts. Similarly, end-of-group markers are usable to generate group done indications and to generate EOG interrupts. The decoder block is configurable to process sub-packets of a packet using either one or multiple decoders.

Abstract: A method of demodulating an AIS signal by receiving the signal, sampling the signal, estimating the carrier frequency, estimating the complex conjugate of the carrier frequency contribution to each sample, multiplying each sample by the complex conjugate and calling the results a base-banded sampled signal (BBSS), correlating the BBSS with known preambles, identifying a maximum magnitude of the BBSS/preamble correlation and its location and the associated preamble, computing a complex inner product of the preamble with a segment of the BBSS, estimating the carrier phase as an argument function of the eighth step result, estimating a complex conjugate of the carrier phase contribution to the BBSS, multiplying each fifth step result starting at the location of the maximum magnitude of the BBSS/preamble correlation by the tenth step result, and demodulating the results starting at that location.

Abstract: The invention relates to a detection method using a receiver of a digital communication system for the detection of a symbol from a received signal, which signal is transmitted by a transmitter of the digital communication system, wherein the symbol is a selected symbol out of a predetermined set of symbols and wherein each symbol of the predetermined set comprises a sequence of chips wherein each of the chips is PSK-modulated according to a selected modulation code.