1665 results about "Channel encoding" patented technology

A method and apparatus for improving the speed and quality of end-to-end data or real-time media transmissions over an internet is disclosed. A media stream being transmitted to the internet is channel coded at the edge of the internet in order to free upstream bit rate for use in source coding the media. The channel coded media stream may then be decoded at a remote edge of the internet to recover lost packets.

The invention discloses a coder based on repeated coding and channel polarization and a coding/decoding method thereof. The coder comprises two coding modules with the same structure; each coding module is provided with a repeated coder group, a bit position mapper with the length of N and a channel polarization device with the length of N, wherein the repeated coder group has m*L output ports and is composed of L sequentially-arranged repeated coders with the repeating times of m; and the two coding modules are connected together through a coding mode selector between the repeated coder and the bit position mapper. The invention provides a concrete method of embedding repeated codes in the channel polarization process to perform channel coding and decoding based on the coder; and compared with the polarization code of the limited length in the prior art, the coding/decoding method disclosed by the invention has stronger error correction capability and obviously improves the transmission performance on the premise of rarely increasing the decoding complexity, is particularly suitable for the practical engineering systems of mobile communication, satellite communication, underwatercommunication and the like, and has good popularization and application prospects.

A method of transmitting data using a plurality of subcarriers in a multi-antenna wireless communication system is disclosed. More specifically, the method includes receiving feedback information from a mobile station (MS), performing channel encoding and modulation independently on user data to be transmitted by each antenna using the received feedback information, determining a phase shift-based precoding matrix for increasing a phase angle of the user data by a fixed amount, and performing precoding using the determined phase shift-based precoding matrix on the user data.

In addition to dedicated channel signal formation units 101-1 to 101-N, control information channel signal formation unit 110 is provided and this control information channel signal formation unit 110 forms control information for carrying out uplink packet transmission. The control information channel signal formation unit 110 multiplexes control information (RG information, ACK/NACK, etc.) directed to a plurality of communication terminals through a channel encoding section 111 according to a multiplexing rule preset between the base station apparatus and each communication terminal and spreads the control information using a spreading code common to the communication terminals through a spreading section 113 and thereby forms a control information channel signal for uplink packet transmission.

A method of supporting a hybrid automatic retransmission request (HARQ) in an orthogonal frequency division multiplexing access (OFDMA) radio access system is disclosed. Preferably, the method comprises receiving a downlink data frame comprising a data map information element and a data burst comprising a plurality of layers, wherein each layer is encoded with a corresponding channel encoder, and wherein the data map information element is configured to support multiple antennas to achieve space time transmit diversity by providing control information associated with each one of the plurality of layers, wherein the control information comprises allocation of acknowledgement status channels corresponding to the plurality of layers, and transmitting in an uplink data frame a plurality of acknowledgement status, each acknowledgement status being associated with whether a corresponding layer of the plurality of layers is properly decoded.

A communication device for simultaneously transmitting information on multiple sub-channels encodes information for each of the multiple sub-channels with a coding scheme to produce channel encoded information. A mask vector derived from a redundancy in the coding scheme, encodes the channel encoded information to transform the channel encoded information into codewords having pairwise Euclidean distance properties identical to those of the channel encoded information, Modulation of the sub-channels in accordance with the codewords in a modulator then produces a composite signal envelope having a peak-to-mean error power ratio (PMEPR) reduced relative to a PMEPR for correspondingly modulated channel encoded information.

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.

The invention relates to a region-of-interest video encoding and transmitting method which realize multi-channel combination, and belongs to the technical field of the video encoding and transmission. The method adopts the following steps: step one, space down sampling is performed to the panoramic video with high resolution collected by a panoramic camera, and then encoding is performed after video with low resolution is obtained; step two, region-of-interest detection is performed to video with high definition collected by a visible-light camera, and self-adaptive switching is performed to the two channels of video, namely, downsized video and down-sampled video, according to the area and the position of the region-of-interest detection; step three, an an infrared thermal imager is used for performing detection and tracking to interest targets, encoding infrared region-of-interest video with primary low resolution, and adjusting quantization parameter to realize code rate control; step four, the priority of the three channels of video is set, protecting channel encoding for non-uniform channel is performed according to the priority, and the code is multiplexed into one channel of code stream to be sent to the channel for transmission, and code rate distribution of the channel bandwidth is performed according to the priority. The method guarantees precise detection and high quality encoding to the region of interest when ensuring global detection on the complete scene.

The invention provides a method and a device for sending physical uplink control signals in a time-division duplex system, the method comprises following steps: encoding the uplink control signals with a communication channel to obtain coded bits, modulating the coded bits with QPSK to obtain modulation symbols, transforming the modulation symbols with DFT to obtain symbols on a frequency domain,expanding the symbols on the frequency domain with time-domain through adopting a CAZAC root sequence to respectively obtain a first signal and a second signal which are sent on two time slots, mapping the first signal and the second signal on an information symbol which is corresponded with a PUCCH reference signal structure 2, and combining the information symbol and the reference signal into asignal which will be sent by a sub-frame. The invention can well satisfy the performance requirement and the covering requirement that a plurality of ACK/NACK can be sent on an uplink sub frame.

A method for hard-decision channel decoding of tail-biting convolutional codes includes the step of receiving from a channel an input bit stream encoded by a tail-biting convolutional channel encoder. The encoder includes a number of memory elements and a rate. The input bit stream includes a series of symbols; each symbol includes a number of bits; the number of bits is related to the rate of the encoder. The method further includes the step of assuming a probability for each possible initial state of the encoder. The method further includes the step of decoding each symbol of the input bit stream using majority logic, with reference to a trellis structure corresponding to the encoder. The trellis structure represents: a number of states related to the number of memory elements of the encoder; a plurality of transitional branches; and a number of stages related to the number of symbols in the input bit stream.

Disclosed is an adaptive transmit and receive method and device in a multiple-antenna wireless communication system. A transmit mode comprises different main transmit modes each of which includes one or both of a sub-transmit mode based on STBC and a sub-transmit mode based on SM. A receiver calculates an STBC performance parameter and a SM performance parameter, and a transmitter uses the parameters to determine a main transmit mode with maximum data rates and select a sub-transmit mode for minimizing power consumption. The transmitter channel-encodes, modulates and antenna-maps input data according to the selected transmit mode, and outputs results to the receiver. The receiver antenna/symbol-demodulates and channel-decodes the received data.

The invention relates to a low-density parity check code method which supports any code rate/length, and a relative device. Wherein, said device comprises an expand factor z calculator, to calculate out expand factor and output z value to shorten coder; a shorten coder for obtaining the shortened data and outputting it to delete code bit device; a delete code bit device for inputting shorten code, selecting and deleting the bit at certain position with confirmed property of delete code, and outputting the code after deletion. The invention can produce a coder with different code ratios and different code lengths of LDPC code, while they have unique base matrix. The invention can save hardware cost, improve code flexibility and improve its application.

The present invention relates to a transmitter in an OFDM system for improving the PAPR, and a method thereof. According to the exemplary embodiment of the present invention, channel encoding is performed in order to correct a data transmission error of a radio channel, a predetermined bit of the channel encoded data is bit-inverted by using a mask bit or a mask bit sequence, and a PAPR of the signal is reduced. Accordingly, reduction of transmission efficiency which has been generated in block coding and DSI methods is not generated when the signal is transmitted because an additional bit is not required.

A video encoding/decoding system based on 3D wavelet decomposition and the human perceptual model is implemented. JND is applied in quantizer design to improve the subjective quality of compressed video. The 3D wavelet decomposition helps to remove spatial and temporal redundancy and provides scalability of video quality. In order to conceal the errors that may, occur under bad wireless channel conditions, a slicing method and a joint source channel coding scenario, that combines RCPC with CRC and utilizes the distortion information to allocate convolutional coding rates are proposed. A new subjective quality index based on JND is presented and used to evaluate the overall system performance at different signal to noise rations (SNR) and at different compression ratios. Due to the wide use of arithmetic coding (AC) in data compression, it is considered as a readily available unit in the video codec system for broadcasting. A new scheme for conditional access (CA) sub-system is designed based on the compression graphic property of arithmetic coding. Its performance is analyzed along with its application in a multi-resolution video compression system. This scheme simplifies the conditional access sub-system and provides satisfactory system reliability.

A MIMO multiple transmission device, comprising a packet data block generator (111) for generating a packet data block as a resent unit for hybrid ARQ; a CRC adder (112) for adding an error detection code; a channel encoder (113) for performing channel encoding, the packet data block generator, the CRC adder and the channel encoder being coupled in series in one or more data streams; a parallel-to-serial converter (114) for converting output of the channel encoder to serial form; an interleaver between transmission streams (115) for performing interleaving between transmission streams on outputs from the parallel-to-serial converter; a serial-to-parallel converter (116) for converting outputs from the interleaver between transmission streams to parallel form; a coding rate changer (117) for changing a coding rate; and a data modulator (119) for modulating data, the coding rate changer and the data modulator being connected in series in plural data streams divided by the serial-to-parallel converter.

A method, apparatus, and system for generating and transmitting a physical broadcast channel (PBCH) are provided. A base station may perform a first scrambling process on PBCHs in a time period before a channel coding, and perform a second scrambling process after the channel coding. PHCH payloads and PBCH DMRS may provide information bits to be used in the scrambling processes.