Embodiments of the present invention relate to the field of communications, and provide a decoding method and a decoder, which are used to reduce decoding complexity. The method includes: receiving a to-be-decoded signal; performing region decision on the to-be-decoded signal according to a region decision rule formed by S region decision formulas, to acquire a region decision result; acquiring N constellation points according to the decision result, where the N constellation points are separately constellation points that are in the N subsets and that are closest to the to-be-decoded signal; acquiring N non-encoded bits corresponding to the N constellation points, and branch metrics between the to-be-decoded signal and the N constellation points; and performing Viterbi decoding based on the branch metrics and the N non-encoded bits, and outputting a decoding result corresponding to the to-be-decoded signal. The present invention is applicable to a signal decoding scenario.

Method and receiver jointly detect and decode a part of an encoded, spread and modulated signal received on a channel in a wireless communication network and corrupted by channel multipath. Differences between the received signal and noiseless theoretical signals corresponding to each of the possible values of the part are calculated using hypothetical transmission matrices. The smallest difference corresponds to the actual value of the part.

A carrier-phase recovery method includes: (i) applying a first carrier-phase recovery algorithm to complex-valued symbols of a signal received by a product detector, yielding coarse phase-estimates, the signal being modulated per an M-QAM scheme; (ii) modelling the coarse phase-estimates as a weighted sum of M probability-density functions of an M-component mixture model; (iii) optimizing the M probability-density functions with an expectation-maximization algorithm to yield M optimized probability-density functions; (iv) mapping, based on the M optimized probability-density functions, the coarse phase-estimates to one of M symbols corresponding to the QAM scheme, each coarse phase-estimate mapped to a same symbol belonging to a same one of M clusters; (v) applying a second carrier-phase recovery algorithm to each of the M clusters to generate refined phase-estimates each corresponding to a respective coarse phase-estimate; and (vi) mapping, based on the M optimized probability-density functions, each refined phase-estimate to one of the M symbols.

A method of receiving a signal by a receiver in a mobile communication system is provided. The method includes: receiving a reference signal from a transmitter; determining first channel information based on the received reference signal; receiving a data signal based on the first channel information; and determining second channel information based on the received data signal and the first channel information. Iterative channel estimation is performed to reduce channel estimation errors by determining errors of signals received from a turbo decoding unit and using symbol information as pilots even in subcarriers where the pilot signals are not transmitted, and to increase the accuracy of LLR calculation through an iteration process such as a detection and decoding process in comparison with the conventional technology, thereby increasing the reception performance of the turbo decoding unit and improving communication efficiency.

Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.

A sequence of symbols is received on a first channel. A noise contribution of a given synchronization symbol is estimated; a reference noise contribution of at least one further symbol is estimated. Based on the noise contribution and further based on the reference noise contribution the given synchronization symbol is selectively considered when determining a coupling coefficient of crosstalk between the first channel and a second channel.

In a receiver of Quadrature Amplitude Modulation (QAM) signal, the received QAM signal is divided into multiple Quadrature Phase Shift Keying (QPSK) symbol streams. A Maximum Likelihood Symbol Estimation (MLSE) is performed on each QPSK symbol stream to recover information bits in the received QAM signal. In one advantageous aspect, complexity of implementation can be reduced by performing MLSE on QPSK signals instead of QAM signals.

A method for detecting a sent sequence, a receiver, and a receiving device in order to simplify an algorithm for detecting a sent sequence and improve detection efficiency. The method for detecting a sent sequence includes determining a maximum possible candidate value of each element in N elements of a received element sequence to obtain N maximum possible candidate values, where N is a positive integer, determining state sequences corresponding to the N maximum possible candidate values as reserved sequences to obtain N groups of reserved sequences, performing likelihood computation on the N groups of reserved sequences, and setting a reserved sequence that is in the N groups of reserved sequences and is most consistent with the element sequence as a detected sent sequence.

Embodiments of this application provide an information processing method and a coding apparatus. An information bit sequence includes a K-bit information block. The information bit sequence is to be processed into an encoded bit sequence with a target code length M. For a given code rate R, when the length K of the information block is greater than a preset threshold, the information bit sequence is segmented into two or more segments. Each segment is polar encoded into an encoded subsequence. The encoded subsequence has a length that equals to a mother code length Ni, and i=1, 2, . . . , p. Each of the p encoded subsequences is rate matched to obtain a rate-matched encoded subsequence. A rate-matched encoded subsequence i of the p rate-matched encoded subsequences has a code length Mi. The p rate-matched encoded subsequences are concatenated into an encoded bit sequence which has a code length M.

An apparatus and method is disclosed with embodiments of a: 1. digital to analog and reference time converter; 2. analog and reference time to digital converter; 3. Sheahan non-linear time-varying, analog and digital control system; and 4. Sheahan Communication Channel are described in detail herein. Some embodiments use time stamp having 72 bits of time data sufficient to identify each clock pulse of a 9.192631770 GHz clock signal plus an additional 8 bits representing 2.sup.8=256 interpolated clock phases in order reach a resolution of approximately 0.425 picoseconds per clock phase. Thus an 80 bit time stamp is generated and used as described herein.