286 results about "Channel decoder" patented technology

An enhanced 8-VSB reception system and E8-VSB data demultiplexing method, by which an E8-VSB signal can be stably received as well as a previous ATSC 8VSB signal, is disclosed. Herein, the enhanced data are coded at ½ code rate and ¼ code rate in the new E8-VSB transmission system compatible with the conventional ATSC 8VSB system, respectively. The ½ and ¼ enhanced data are multiplexed by 164-byte packet unit according to the previously determined multiplexing format and further pre-processed to output as the format of the MPEG transport packet. And, the pre-processed enhanced data and the main data are multiplexed again by 188-byte packet unit according to the previously determined multiplexing format. The E8-VSB map information, which was inserted in the field sync section in the E8-VSB transmission system to be transmitted, is extracted to generate the information indicating the attributes of the respective E8-VSB data. The normal data, ½ enhanced data, and ½ enhanced data are separated from each other to be decoded in the channel decoder.

The present invention relates to improved multiple access communications. In one form, the invention relates to an improved signal processing method and apparatus for an iterative method of determining the reception of a signal in a multi user packet based wireless OFDM (Orthogonal Frequency Division Multiplexing) communication system. In other forms the present invention provides recursive filtering for joint iterative decoding in a variety of systems and functions such as linear multiple access channel decoders, iterative equalisation, iterative joint channel estimation and detection/decoding, iterative space-time processing, iterative multi user interference cancellation and iterative demodulation. In one particular form the present invention provides an iterative decoding circuit for a wireless multiuser communications receiver comprising a first signal processing means for receiving at least one received signal, said first signal processing means comprising at least two linear iterative filters such that the first linear iterative filter provides an estimate of a selected received signal to an estimated signal output and a second linear iterative filter provides estimates of at least one other received signal, delayed by one iteration cycle, to an input of said first linear iterative filter, a second signal processing means for receiving the estimated signal output of the first linear iterative filter and providing a further received signal estimate to the input of the first signal processing means in a succeeding iteration cycle of the decoding circuit.

A data transmission system is provided for transmitting user data to and receiving data from a communication channel, including a parity check matrix having M tiers, wherein M≦2, Dmin=2*M for M=1 . . . 3 or 2*M≦Dmin≦6 for M>3, wherein Dmin is the minimum Hamming distance, tc=M, wherein tc is the column weight, and cycle−4=0. A linear block encoder encodes the user data in response to the parity check matrix, and a transmitter transmits an output of the linear block encoder to the communication channel. A soft channel decoder decodes data, and a soft linear block code decoder to decode data decoded by the soft channel decoder in response to the parity check matrix.

In a multi-channel encoder generating several different parameter sets for reconstructing a multi-channel output signal using at least one transmission channel, the data stream is written such that the two parameter sets are decodable independently of each other. Thus, a multi-channel decoder is enabled to skip a parameter set which is marked as optional and/or has a higher version number when reading the data stream and still to perform a valid multi-channel reconstruction using a data set marked as mandatory or a data set having a sufficiently low version number. This achieves a flexible encoder/decoder concept suitable for future updates characterized by backward compatibility and reliability.

An apparatus and method are provided for normalizing input soft metric to a channel decoder in a wireless communication system. A demapper generates soft metric using an in-phase component (X_k) and a quadrature component (Y_k) of a received modulated symbol (R_k), a channel fading coefficient (g_k) and a constant value (c) defined by a modulation order of the received modulated symbol. A normalizer receives the soft metric, computes a normalized log likelihood ratio (LLR) by multiplying the soft metric by a ratio of the constant value to a noise variance value, transforms the normalized LLR into a desired range and a desired number of bits, and outputs an input LLR of the channel decoder.

A transmitter is provided for transmitting data to a communication channel and a receiver receives the data from the communication channel. The transmitter comprises an encoder to encode data and a linear block encoder to encode data encoded by the encoder. The receiver comprises a soft channel decoder to decode the data, and a soft linear block code decoder to decode data decoded by the soft channel decoder. In the first iteration, the soft channel decoder decodes data received by the receiver. In succeeding iterations, the soft channel decoder decodes the data received by the receiver and utilizes information from the soft linear block decoder from an immediate preceding iteration. A decision circuit selects an output of the soft linear block decoder if an evaluated criterion is less than a threshold, or an output of the soft channel decoder if the evaluated criterion is greater than the threshold. A decoder decodes an output of the threshold check circuit.

An embodiment of the present invention provides a wireless telephone including a receiver module, a channel decoder, a speech decoder, and a speaker. The receiver module receives a plurality of versions of a voice signal, wherein each version of the voice signal comprises a plurality of speech frames. The channel decoder is configured to decode a speech parameter associated with a first speech frame from a first version of the voice signal, wherein decoding the speech parameter includes selecting an optimal bit sequence from a plurality of candidate bit sequences and wherein the selection of the optimal bit sequence is based in part on a second speech frame from a second version of the voice signal. The speech decoder decodes at least one of the first or second versions of the voice signal based on the speech parameter to generate an output signal. The speaker receives the output signal and produces a sound pressure wave corresponding thereto.

Systems and methods for decoding neural and/or electromyographic signals are provided. A system can include at least one single channel decoder. Optionally, the system can include a demixer in operable communication with the single channel decoders. Each single channel decoder can include a filter to attenuate noise and sharpen spikes in the neural and/or electromyographic signals, a detection function to identify spikes, and a demodulator to get a real-time estimate of motor intent.

An apparatus for receiving data through channels in a communication system including a first channel for transmitting control information related to a second channel and the second channel for transmitting packet data, the apparatus comprising: a first channel decoder for decoding the first channel and outputting control information; an active Walsh mask storing section for storing a Walsh mask acquired from the control information; a second channel decoder for decoding the second channel using the Walsh mask stored in the active Walsh mask storing section and outputting a decoding result; and a control unit for changing the Walsh mask to a previous Walsh mask if a Walsh mask error is determined according the decoding result.

A disk drive using a read/write channel including an iteration decoder for performing iterative decoding processing is disclosed. The iteration decoder has an RLL error detector for detecting a burst error portion from an LLR group output from the channel decoder, and an LLR adjuster. The LLR adjuster makes adjustment by reducing the value of the LLR group corresponding to the detected burst error portion.

The invention provides a code modulation method and system adopting a Raptor-like Irregular QC-LDPC code. The code modulation method includes the steps that the code modulation system receives input information bits; LDPC channel coding is conducted on the information bits according to a check matrix of the Raptor-like Irregular QC-LDPC code to generate coding bits; bit mapping is conducted on the coding bits to obtain mapping bits; constellation mapping is conducted on the mapping bits to obtain constellation mapping symbols, and the constellation mapping symbols pass through an equivalent transmission channel to obtain receiving symbols; bit soft de-interleaving is conducted on extrinsic information of the mapping bits to generate prior information of the coding bits; the prior information of the coding bits is decoded to obtain the extrinsic information of the coding bits; bit soft interleaving is conducted on the extrinsic information of the coding bits to generate the prior information of the mapping bits, and LDPC decoding results are output after multiple iterations. The code modulation method improves the flexibility of a communication system, simplifies a realization method of a channel decoder applied to a variety of services and facilitates improvement of the handling capacity and the expansibility of a code modulation system.

A communication relay apparatus for providing a network-encoded information unit sequence comprises a first channel decoder which is configured to supervise a first wireless channel, to receive a first channel-encoded sequence of information units from a first data source via the first wireless channel and to decode the first channel-encoded sequence of information units to obtain a first decoded sequence of information units. Furthermore, the communication relay apparatus comprises a second channel decoder which is configured to supervise a second wireless channel, to receive a second channel-encoded sequence of information units from a second data source via the second wireless channel and to decode the second channel-encoded sequence of information units to obtain a second decoded sequence of information units, the first and second wireless channels being different from each other. Finally, the communication relay apparatus comprises a network-encoder which is configured to encode information of the first and second decoded sequences of information units into the network-encoded information unit sequence and wherein the network-encoder is further configured to wirelessly transmit the network-encoded information unit sequence to a data sink.

A lossless encoder and decoder are provided for transmitting a multichannel signal on a medium such as DVD-Audio. The encoder accepts additionally a downmix specification and splits the encoded stream into two substreams, such that a two-channel decoder of meagre computational power can implement the downmix specification by decoding one substream, while a multichannel decoder can decode the original multichannel signal losslessly using both substreams. Further features provide for efficient implementation on 24-bit processors, for confirmation of lossless reproduction to the user, and for benign behaviour in the case of downmix specifications that result in overload. The principle is also extended to mixed-rate signals, where for example some input channels are sampled at 48 kHz and some are sampled at 96 kHz

The invention discloses a system and a method for realizing iterative timing synchronization of a continuous phase modulation (CMP) signal; the system is provided with a sender, and is composed of a maximum likelihood detector, a de-interleaver, a channel decoder and an information destination which are connected in order, and an interleaver which is used for interleaving an output signal of the channel decoder and feeding back the interleaved output signal to the maximum likelihood detector; a built-up circuit of the maximum likelihood detector comprises a match filter set, a demodulator, and a timing synchronization loop circuit arranged between the match filter set and the demodulator; a detecting method based on a maximum likelihood criterion is used for demodulating the received CPM signal, detecting and computing a timing error value and adjusting the time delay, and outputting a bit likelihood ratio of each symbol. Based on a timing error detecting method of the maximum likelihood criterion, a soft information assistance fed back by the channel decoder is used for realizing the timing synchronization to obtain an accurate timing deviation estimation; meanwhile, an iterativeprocess is used between the demodulation and the decoding to maximally improve an error bit ratio of the system; and the system and method for realizing iterative timing synchronization of the CMP signal can be applied in long-distance communication with the requirement of high performance.

The invention relates to a compressed sensing PIE system based on space-frequency coding. In a transmitter, a channel encoder, a modulator, an orthogonal converter, a symbol interleaver, a serial-to-parallel converter and a space-frequency encoder are successively connected in series, the space-frequency encoder is connected with two subcarrier mapping devices of the same structure, and each subcarrier mapping device is successively connected with an up sampler, a reverse discrete Fourier transformer, a cyclic prefix adder, a parallel-to-serial converter, a D/A conversion and RF emitter and an emission antenna. A receiver comprises a reception antenna, an RF front-end converter, an A/D converter, a Doppler frequency offset estimator, a Doppler frequency offset compensator, a cyclic prefix remover, a discrete Fourier transformer, a compressed sensing interference eliminator, a frequency-domain down sampler, a channel estimator, a space-frequency decoder, a symbolic solution interleaver, a reverse orthogonal converter and a channel decoder successively in serial connection. The compressed sensing algorithm can be directly utilized to reconstruct pulse signals of a range finder and converts the pulse signals to the frequency domain for elimination, and thus, the pulse signals of the range finder are effectively inhibited.