1517 results about "Round complexity" patented technology

A scheme for stereo and multi-channel synthesis of inter-channel correlation (ICC) (normalized cross-correlation) cues for parametric stereo and multi-channel coding. The scheme synthesizes ICC cues such that they approximate those of the original. For that purpose, diffuse audio channels are generated and mixed with the transmitted combined (e.g., sum) signal(s). The diffuse audio channels are preferably generated using relatively long filters with exponentially decaying Gaussian impulse responses. Such impulse responses generate diffuse sound similar to late reverberation. An alternative implementation for reduced computational complexity is proposed, where inter-channel level difference (ICLD), inter-channel time difference (ICTD), and ICC synthesis are all carried out in the domain of a single short-time Fourier transform (STFT), including the filtering for diffuse sound generation.

Improved approaches to flexibly implementing graphic equalizers on media players are disclosed. These approaches provide dynamic order reduction of a multi-band graphic equalizer so that equalizer effects can be timely performed with only limited computational resources. In one embodiment, a media player receives a media item and associated equalizer settings for a multi-band graphic equalizer. The media player can then automatically (i.e., without user action) approximate the multi-band graphic equalizer with the equalizer settings for the media item using a fewer number of filters. Fewer filters means order reduction, and thus reduction in computational requirements. After the multi-band graphic equalizer is approximated, the media player can present the media item to its user in accordance with the reduced complexity, approximated equalizer.

The disclosed teachings provide methods and systems for efficient evaluation of XPath queries. In particular, the disclosed evaluation methods require only polynomial time with respect to the total size of an input XPath query and an input XML document. Crucial for the new methods is the notion of “context-value tables”. This idea can be further refined for queries in Core XPath and XSLT Patterns so as to yield even a linear time evaluation method. Moreover, the disclosed methods can be used for improving existing methods and systems for processing XPath expressions so to guarantee polynomial worst-case complexity.

The disclosed technology provides a less resource intensive way to decode a parity check code using a modified min-sum algorithm. For a particular parity check constraint that includes n variable nodes, an LDPC decoder can compute soft information for one of the variable nodes based on combinations of soft information from other variable nodes, wherein each combination includes soft information from at most a number d of other variable nodes. In one embodiment, soft information from one of the other variable nodes is used in a combination only if it corresponds to a non-most-likely value for the other variable node.

The invention discloses a channel-polarization-based encoder for a staggered structure duplication code, and an encoding method and decoding methods thereof. The encoder consists of a duplication bit buffer with a storage capacity of L bits, a bit position mapper with a length N and a channel polarization device with the length N which are connected in sequence. The encoding method based on the encoder comprises the following steps of: embedding duplicated encoding into a channel polarization process, and introducing a duplicated relationship between parts of the bits of code blocks transmitted in sequence during the channel polarization for encoding. In addition, the invention further provides two decoding methods, which comprise the following steps of: decoding by using a simple and rapid successive cancellation (SC) algorithm, and performing iterative decoding by using a Tanner-graph-based belief propagation algorithm with excellent performance. On the basis of the innovative structure encoder, the encoding and decoding methods provided by the invention are stronger in error correction capability under the condition of not increasing the decoding complexity, and the transmission performance is obviously improved. The encoding and decoding methods are particularly applicable to an actual communication engineering system and have a good popularization and application prospect.

Three block concepts are introduced in HEVC: coding unit (CU), prediction unit (PU), and transform unit (TU). The overall coding structure is characterized by the various sizes of CU, PU and TU in a recursive fashion. For transform processing in current HEVC, a hierarchy RQT (Residual Quad Tree) is used and the TU size is related to the CU size, but independent of the PU size. This results in high encoding complexity and also causes increased processing time to process the syntax of residual quad tree. Accordingly a modified transform unit partition with reduced complexity is disclosed. According to an embodiment, the TU size may be restricted to the minimum of PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In another embodiment, the maximum TU size equals to maximum of PU width and height, and the minimum TU size equals to minimum of the PU width and height, except for a 2N×2N coding unit with the 2N×2N partition type. In yet another embodiment, the TU size is selected between 2N×2N and N×N for the 2N×2N, 2N×N, N×2N and N×N partition types. The syntax element, split_transform_flag, is used to indicate the selection of 2N×2N or N×N TU size when needed. Furthermore, a method with reduced complexity of selecting the best merge candidate for the 2N×2N CU merge mode is disclosed. The method relies on R-D cost associated with the motion vector of merge candidate to reduce required computation.

A scalable, minimum node complexity, energy efficient, and error-resilient routing method for wireless sensor networks is described. The network is partitioned into regions by power controlled base station scans using a directional antenna. Routing is performed using only local location information and instructions received from the base station at each sensor node with minimum processing and control overhead, thus allowing simple, low-cost sensor designs. Sensors in the network provide to a base station reports of the condition of the sensors themselves, and these reports are analyzed by the base station to determine improved routing instructions, which are then provided to the sensor nodes in control messages. Each data packet is relayed in an interleaved, loop-free mesh of sectors toward the base station, making data delivery robust to sensor failures and transmission errors. The disclosure also contains descriptions for simple edge-based tasking, query, code distribution, and network programming for sensor nodes. The method is suitable for large-scale, dense sensor networks for detection, alarming, and monitoring applications.

An algorithmic soft-decision decoding method for Reed-Solomon codes proceeds as follows. Given the reliability matrix Pi showing the probability that a code symbol of a particular value was transmitted at each position, computing a multiplicity matrix M which determines the interpolation points and their multiplicities. Given this multiplicity matrix M, soft interpolation is performed to find the non-trivial polynomial Q<HIL><PDAT>M</SB><PDAT>(X,Y) of the lowest (weighted) degree whose zeros and their multiplicities are as specified by the matrix M. Given this non-trivial polynomial Q<HIL><PDAT>M</SB><PDAT>(X,Y), all factors of Q<HIL><PDAT>M</SB><PDAT>(X,Y) of type Y-f(X) are found, where f(X) is a polynomial in X whose degree is less than the dimension k of the Reed-Solomon code. Given these polynomials f(X), a codeword is reconstructed from each of them, and the most likely of these codewords selected as the output of the algorithm. The algorithmic method is algebraic, operates in polynomial time, and significantly outperforms conventional hard-decision decoding, generalized minimum distance decoding, and Guruswami-Sudan decoding of Reed-Solomon codes. By varying the total number of interpolation points recorded in the multiplicity matrix M, the complexity of decoding can be adjusted in real time to any feasible level of performance. The algorithmic method extends to algebraic soft-decision decoding of Bose-Chaudhuri-Hocquenghem codes and algebraic-geometry codes.</PTEXT>

The invention provides a blind detection method. The method comprises the following steps of: determining a PDCCH DCI format candidate set for blind detection by using the transmission mode and historical dispatching information which are configured by a network for UE, and preliminarily determining the number of CCE resources for bearing a PDCCH by using signal-to-noise ratio measurement results of channels and channel changes of adjacent two-time scheduling so as to effectively reduce trying times of UE PDCCH blind detection. Therefore, the blind detection method can reduce calculated amount and processing complexity of the UE, reduces the power consumption of the UE and improves system performance.

A method and apparatus are provided for implementing an impulse ultra-wideband communications system which combines the technique of transmitted reference (TR) with a code-sifted reference scheme that separates the reference and the data pulses with a sequence of codes such as a subset of Walsh codes. The combination of the two techniques in ultra-wideband (UWB) radio systems removes the wideband delay elements required by conventional TR UWB systems. The invention provides a system with no analog carriers and lower complexities than other UWB systems, and which has better performances, higher tolerance to nonlinearity, and larger capacities

The present invention relates to systems and methods for motion estimation and mode decision for low-complexity H.264 standard decoders. The present invention includes a method for optimizing the selection of motion vectors and motion compensation block modules in a video encoder in order to decrease the complexity of the video upon decoding. The novel method of the present invention may include novel steps for selecting motion vectors, block modes, and for applying a complexity-control algorithm to encode the received input video data sequence in accordance with the identified target complexity level. The present invention may be implemented in accordance with current and future video decoding standards to optimize decoding by reducing decoding complexity and thereby reducing required resources and power consumption.

A MIMO receiver is provided with a preprocessor for performing QR decomposition of a channel matrix H wherein the factored reduced matrix R is used in place of H and Q*y is used in place of the received vector y in a maximum likelihood detector (“MLD”). The maximum likelihood detector might be a hard-decision MLD or a soft-decision MLD. A savings of computational complexity can be used to provide comparable results more quickly, using less circuitry, and/or requiring less consumed energy, or performance can be improved for a fixed amount of time, circuitry and/or energy. Where the MLD uses approximations, such as finite resolution calculations (fixed point or the like) or L1 Norm approximations, the reduced number of operations resulting from using the reduced matrix results in improved approximations as a result of the finite resolution operations. Other methods of reducing the channel matrix might be used for suitable and/or cumulative advantages.

The universal forward error-correction coding system provides adjustable code rates and coding gains to greatly benefit the design of many modern digital communications (data storage) systems. The channel encoding and decoding methods are universal such that a single encoder and a single decoder can be used to implement all the forward error-correction codes of different code rates. This universal forward error-correction coding system also includes a novel systematic code generation procedure that has the capability of generating many classes of codes that provide the best balance between coding gain performance and implementation complexity.

Soft symbol decoder algorithms for multiple input, multiple output (MIMO) receivers reduce the search complexity by searching over fewer than all possible combinations of transmitted symbols to compute log metrics for each transmitted bit from each transmit antenna. In one algorithm, a sub-optimal set of transmitted symbols is computed and the transmitted symbols are restricted to neighboring constellation points of the sub-optimal set. In another algorithm, all constellation points are searched for every antenna except one. In yet another algorithm, constellation points are searched excluding more than one antenna. The non-searched antenna(s) can be handled by either a bit stuffing or a soft slicing technique.

The invention discloses a method for detecting code similarity based on semantic analysis of a program source code, which relates to computer program analyzing technology and a method for detecting complex codes of computer software. The method solves the prior problems of low similarity detection accuracy and high computing complexity on the codes of different syntactic representations and similar semantemes, and also solves the problem of incapability of realizing large-scale program code similarity detection. The method comprises the following steps: resolving two segments of source codes to be detected into two control dependence trees of a system dependence graph respectively and executing basic code standardization respectively; utilizing a measure method to extract candidate similar code control dependence trees of the control dependence trees which are subjected to the basic code standardization; executing an advanced code standardization operation on extracted candidate similar codes; and computing semantic similarity to obtain a similarity result so as to finish the code similarity detection. The method is applied to source code piracy detection, software component library query, software defect detection, program comprehension and the like.

Repeaters, event those having digital processing, exist. The significant drawback of these digital repeaters is that the computational complexity or the processing speed has to be very high in order to guarantee, particularly when compensating for echo, that the necessary delay does not excessively impair the performance. The aim of the invention is to provide a structure of the repeater in which the computational complexity is reduced without this reduction having a negative effect on the performance during signal filtering and/or suppression of natural oscillation. To this end, the invention provides that in order to carry out bandpass filtering, adaptive pre-equalization and suppression of the natural oscillation, the components of the repeater in the uplink branch and downlink branch are arranged in a designated sequence, whereby duplex filters are used for coupling both repeater branches to the antennes. In addition, only one reconfiguration in the modules at the user is necessary in order to adapt to user-specific requirements. The invention is used in the field of digital repeaters for data systems technology and telecommunications technology.

A methodology is described to reduce the complexity of filters for face recognition by reducing the memory requirement to, for example, 2 bits/pixel in the frequency domain. Reduced-complexity correlations are achieved by having quantized MACE, UMACE, OTSDF, UOTSDF, MACH, and other filters, in conjunction with a quantized Fourier transform of the input image. This reduces complexity in comparison to the advanced correlation filters using full-phase correlation. However, the verification performance of the reduced complexity filters is comparable to that of full-complexity filters. A special case of using 4-phases to represent both the filter and training/test images in the Fourier domain leads to further reductions in the computational formulations. This also enables the storage and synthesis of filters in limited-memory and limited-computational power platforms such as PDAs, cell phones, etc. An online training algorithm implemented on a face verification system is described for synthesizing correlation filters to handle pose/scale variations. A way to perform efficient face localization is also discussed. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

A rate control system is disclosed for video coding applications. The rate controller assigns a quantization parameter for video data in a picture in response to complexity indicators indicative of spatial complexity, motion complexity and/or bits per pel of the picture. A virtual buffer based quantizer parameter is proposed based on a virtual buffer fullness analysis and a target rate estimate, which is derived from the complexity indicators. A second quantizer parameter is proposed from a linear regression analysis of quantizer parameters used to code previously coded pictures of similar type (e.g., I pictures, P pictures or B pictures). A coding policy decision unit defines a final quantizer parameter from a comparison of the two proposed quantizer parameters.

The invention relates to a synchronization and channel response estimation method which is applicable to an OFDM system, the technical proposal is as follows: a maximum likelihood criterion ML-based cost function for the symbol timing synchronization, the carrier frequency synchronization and the channel parameter joint estimation is proposed by using an OFDM system model under a frequency selective fading channel and against the requirements on the accuracy of the transmission of high-quality information of the next generation of wireless communication system and the existing OFDM wireless communication system. A system architecture and a strategy of joint estimation symbols of timing offset Theta, carrier frequency offset Epsilon and channel impulse response h are derived from the cost function. The method comprises the following steps of carrying out the coarse synchronization and the channel response estimation and carrying out the fine synchronization and the calculation of a channel estimated value. The method can realize the balance between the calculation precision and the calculation complexity, increase or reduce the times of the iteration of the fine synchronization according to an actual system, reduce the interference during the wireless transmission, further improve the reliability of the system and improve the availability of the system.

The invention discloses a mapreduce-based multi-GPU (Graphic Processing Unit) cooperative computing method, which belongs to the application field of computer software. Corresponding to single-layer parallel architecture of common high-performance GPU computing and MapReduce parallel computing, a programming model adopts a double-layer GPU and MapReduce parallel architecture to help a developer simplify the program model and multiplex the existing concurrent codes through a MapReduce program model with cloud computing concurrent computation by combining the structure characteristic of a GPU plus CPU (Central Processing Unit) heterogeneous system, thus reducing the programming complexity, having certain system disaster tolerance capacity and reducing the dependency of equipment. According to the computing method provided by the invention, the GPU plus MapReduce double concurrent mode can be used in a cloud computing platform or a common distributive computing system so as to realize concurrent processing of MapReduce tasks on a plurality of GPU cards.

Estimates of spectral magnitude and phase are obtained by an estimation process using spectral information from analysis filter banks such as the Modified Discrete Cosine Transform. The estimation process may be implemented by convolution-like operations with impulse responses. Portions of the impulse responses may be selected for use in the convolution-like operations to trade off between computational complexity and estimation accuracy. Mathematical derivations of analytical expressions for filter structures and impulse responses are disclosed.

The invention provides a shared convolutional neural network-based insulator detection method and apparatus. The method comprises the steps of shooting a power transmission line image of a substation by utilizing a patrol robot; and obtaining an optimal position of an insulator in the power transmission line image by utilizing a shared convolutional neural network obtained by training an RPN and a Fast R-CNN. According to the method and the apparatus, the insulator in the power transmission line image is detected by utilizing the shared convolutional neural network obtained by training the RPN and the Fast R-CNN of a shared partial convolutional layer and a pooling layer; and compared with the prior art, the calculation complexity can be lowered, real-time detection of the insulator under a complex background is achieved, and accurate identification and locating of the insulator in a robot patrol image are realized.

The invention provides a generation method of a vector quantization code book. In the method, a global optimization method based on a random relaxation technology is introduced; and while iteratively updating the code book every time, random disturbance is generated and added to a corresponding code word, thus local convergence is effectively avoided during the process of updating the code book. The method can further rationally optimize a code book structure and bit positions of the code word according to the inherent characteristic of channel statistical distribution of a wireless communication system and the requirement on orthogonality of user scheduling in a base station in an MIMO system on the selected users. In addition, a method for expanding the code book is also introduced in order to improve the robustness of the code book in a multi-channel statistical distribution environment, and the size of the code book can be flexibly adjusted according to specific conditions. As the antenna number of the base station and downlink user equipment is greatly increased based on the demand of the development of the future communication system, the method can generate reserved interfaces for the future code book, and can achieve higher quantization and system performance with lower complexity even though the method is used in high-dimensional vector quantization.

A reduced complexity Turbo multi-user detector (MUD) processing system in multiple access communications channels that decreases the likelihood of improper decoding of the final values of interest and decreases the computation complexity for each iteration, thereby allowing for a reduction in the number of iterations performed and lowers the overall complexity without negatively impacting performance. In one form the present invention comprises a multi-user detector coupled to two or more decoder sections, two ore more recoders, and a compare and adjust section in such a manner that data flows iteratively to correct for errors in a computationally efficient manner.

Optimal Decision Feedback Equalizer (DFE) coefficients are determined from a channel estimate by casting the DFE coefficient problem as a standard recursive least squares (RLS) problem and solving the RLS problem. In one embodiment, a fast recursive method, e.g., fast transversal filter (FTF) technique, is used to compute the Kalman gain of the RLS problem, which is then directly used to compute MIMO Feed Forward Equalizer (FFE) coefficients. The FBE coefficients are computed by convolving the FFE coefficients with the channel impulse response. Complexity of a conventional FTF algorithm may be reduced to one third of its original complexity by selecting a DFE delay to force the FTF algorithm to use a lower triangular matrix. The length of the DFE may be selected to minimize the tap energy in the FBE coefficients or to ensure that the tap energy in the FBE coefficients meets a threshold.

A signature sequence is employed in a wireless transmission over a channel and is detected by a receiving station. The signature sequence is selected from a subset of sequences chosen from a set of sequences formed by delay-Doppler shifts of a base sequence. Use of the subset of sequences simplifies detection of the signature sequence by, e.g., facilitating use of a simpler detector structure. A subset of N² sequences of the specially-constructed delay-Doppler shifted sequence set is selected to facilitate more efficient computation of the detection metric. A simplified detector employs algebraic techniques (such as Discrete Fourier 'Transform (DFT)) that exploit prudent sequence assignment strategy. As an advantageous variation, for a particular class of base sequences that can be represented by segments of equal-length sinusoids, even greater complexity reduction can be achieved by segmenting the delay-Doppler correlation accordingly and reusing past outcome in subsequent overlapping segments.

The invention discloses a multi-band structure self-adaptive filter switching method for AEC (acoustic echo cancellation). Firstly, a far-end voice signal is acquired; a voice endpoint is detected, and a VAD (voice activity detection) flag bit and an improved envelope decision threshold are output; the voice signal is fed into a loudspeaker to serve as a desired signal and also input into a self-adaptive filter; the self-adaptive filter adopts a switchable multi-band structure and a corresponding self-adaptive algorithm, parameters of the filter are adjusted by use of the least mean square criterion according to feedback information, and the optimal solution is obtained. According to the provided switching method, voice characteristics are considered sufficiently under the condition that steady maladjustment is guaranteed, and optimized configuration of the convergence rate and the algorithm complexity is realized while advantages of the algorithm in the convergence rate are utilized. During actual application of echo cancellation, a single algorithm does not easily meet various variable demands. The variable switching algorithm provides more probability for a user and has great significance in application of self-adaptive echo cancellation.

The method for compressive sensing (CS) and reconstruction of ultra-wideband (UWB) channels includes building four practically-based dictionaries related to the antenna angles of transmission and angles of arrival that enhance the sparsity of UWB signals. The dictionaries account for the practical effects of the channel, such as pulse dispersion and the unavoidable effects of the antenna. Utilizing the practically-based dictionaries CS is able to reconstruct the UWB signals more efficiently with reasonable complexity. In addition to waveform reconstruction, the dictionaries are used for channel estimation. The CS method can be used with either a single-shot full profile correlator or a Rake receiver. The Rake receiver employs CS in adjusting its parameters to take advantage of the energy available in the strongest propagation paths.

Loading and ordering techniques are provided for one-sided and two-sided vectored line groups, as well as loading methodologies that also can be used on a single line, in communication systems such as DSL binders. For single-user lines, bits and energy are optimally allocated for a given set of parameters, which may include maximum rate, minimum rate, maximum margin, target margin, minimum margin and PSD mask of any shape. Iterations, bit-swapping during loading or adaptive margin update during loading can be used in single-user loading, which has low complexity and can be used for a variety of loading objectives and/or goals, such as rate-adaptive, margin-adaptive and fixed-margin objectives. For multi-user vectoring systems, ordering as well as loading is provided for a supplied rate-tuple within a rate region, determining acceptable user loadings and orderings so that the rate-tuple can be implemented. For one-sided vectored DSL, some loading and ordering determines acceptable allocations of bits, energy and decoding/precoding ordering(s) for each tone of each user for a specified set of rates on the vectored lines. PSD determination, ordering and bit allocation can be iteratively used in multi-user loading and ordering and can augment and alter the criteria used for bit swapping procedures used in single lines (or in bonded multiple lines for a single user) so that a favorable vector of rates is achieved for all users. Order swapping can adjust a bit vector and/or rate vector within a constant-rate-sum convex subset of a hyperplane towards the desired vector of user rates for each of the lines.

The invention discloses a method for quick inter-frame transcoding from H. 264/AVC standard to HEVC standard. The method comprises the following steps: imbedding an H.264/AVC standard code stream into a decoder for decoding, abstracting various information of subblocks during a decoding process, converting extracted information of the subblocks into CU and PU information for HEVC standard in ways of direct correspondence and small blocks forming large blocks, and finally using CU and PU information in HEVC standard coding directly. Since definite CU and PU information is available, quadtree division of CU, performed according to original encoding mode, is not required, ergodic of all possible PU modes under the depth of each CU is not required, and all that is needed is to calculate a PU mode and an intra-frame predicting mode under the depth of a corresponding CU. Therefore, calculating complexity in quadtree division of CU and ergodic under PU mode during transcoding is avoided. According to the transcoding method in the invention, the coding calculation complexity and coding time can be lowered and reduced considerably under the condition of very small loss of bit rate and video quality.