H04L25/03286

Method and apparatus for data-aided iterative channel estimation

An apparatus and a method. The apparatus includes a channel estimation (CE) module, including a first input for receiving pilot resource element (RE) observations, a second input for receiving data RE observations, a third input for receiving log-likelihood ratios (LLRs), and an output; a detector, including a first input connected to the output of the CE module, a second input for receiving data RE observations, and an output connected to the third input of the CE module; and a decoder, including an input connected to the third input of the CE module, and an output.

Method and apparatus for soft bit computation in MIMO decoders
10110346 · 2018-10-23 · ·

Forward Error Correction (FEC) is an essential component of most digital communication systems. The decoders for the FEC perform better when working in soft-decision mode using the Log Likelihood Ratios (LLRs) as the input. Spatial Multiplexing (SM) with Multiple Input Multiple Output (MIMO) is used in many systems for providing high data rate. When SM-MIMO is used in conjunction with FEC, it is important for SM-MIMO decoders to provide soft channel bits to the FEC decoder. The complexity of the SM-MIMO decoders is generally very high, especially when LLRs need to be generated for each bit of the decoded symbol. Conventional methods for LLR generation in SM-MIMO decoders require the storage and sorting of partial and cumulative distance. A method and apparatus are disclosed that compute the LLRs on the fly without requiring extensive storage or sorting of partial and cumulative distance metrics.

Error detection constants of symbol transition clocking transcoding
10089173 · 2018-10-02 · ·

Apparatus, systems and methods for error detection in transmissions on a multi-wire interface are disclosed. A method for transmitting data on the multi-wire interface includes transmitting data on a multi-wire interface includes obtaining a plurality of bits to be transmitted over a plurality of connectors, converting the plurality of bits into a sequence of symbols, and transmitting the sequence of symbols on the plurality of connectors. A predetermined number of least significant bits in the plurality of bits may be used for error detection. The predetermined number of least significant bits may have a constant value that is different from each of a plurality of error values. A symbol error affecting one or two symbols in the sequence of symbols may cause a decoded version of the predetermined number of least significant bits to have value that is one of a plurality of error values.

SIGNAL PROCESSING SYSTEM AND METHOD, AND APPARATUS
20180278448 · 2018-09-27 ·

A signal processing system and method, and an apparatus are provided. A phase recovery apparatus may be used to: receive a feedback signal fed back by an information iteration apparatus, perform, based on the feedback signal, phase recovery on a signal output by an equalizer, and output a phase-recovered signal to a post filtering apparatus, so that the post filtering apparatus performs noise filtering on the phase-recovered signal, and outputs a noise-filtered signal to the information iteration apparatus. To be specific, the phase recovery may be performed, based on the signal fed back by the information iteration apparatus, on the signal output by the equalizer. Because output of the information iteration apparatus is more accurate in determining the signal, precision of the phase recovery can be improved, cycle skipping is reduced, and input signal quality of the post filtering apparatus is improved.

Iterative recovery from baseline or timing disturbances

In certain embodiments, a method may include receiving one or more equalized samples of an input signal. The method may further include mitigating one or more excursions in the one or more equalized samples based on one or more current decisions of an iterative decoding process to generate compensated equalized samples. In addition, the method may include performing iterative decoding operations based on the compensated equalized samples, updating the current decisions of the iterative decoding process and outputting the current decisions as a converged result when the iterative decoding operations have converged for the compensated equalized samples.

COMMUNICATION DEVICE AND METHOD FOR EFFICIENTLY RECEIVING MIMO SIGNALS
20180234205 · 2018-08-16 ·

Communication device adapted for receiving a MIMO signal is provided. The device comprises a first detector adapted to perform a first symbol detection on the MIMO signal using a first detection method, a detection error determination unit adapted to determine a first detection error of the first symbol detection, a detection error judging unit adapted to determine if the first detection error is above or below a detection threshold, and a second detector, adapted to perform a second symbol detection on the MIMO signal using a second detection method, if the detection error judging unit has determined that the first detection error is above the detection threshold. The communication device is adapted to use results of the symbol detection as final symbol detection results, if the detection error judging unit has determined that the first detection error is below the detection threshold.

PARALLEL PROCESSING OF SPHERE DECODERS AND OTHER VECTOR FINDING APPROACHES USING TREE SEARCH
20180176049 · 2018-06-21 ·

Apparatus and methods for finding a vector solution to a tree search problem are disclosed. In some embodiments, the apparatus and methods can be used for sphere decoding. The tree search is performed by: obtaining a tree graph; identifying a plurality of nodes in the tree graph that are likely to be part of the solution to the tree graph; partitioning the tree graph into a plurality of sub-trees, each sub-tree including one or more of the identified nodes; processing the plurality of sub-trees in parallel by allocating one or more of the processing elements to each of the sub-trees; and determining the solution based on results of the sub-tree processing.

MULTI-STAGE SAMPLER WITH INCREASED GAIN
20180115442 · 2018-04-26 ·

Generating first and second discharge control signals in response to a clock signal and an input voltage signal, the first and second discharge control signals decreasing at different rates to a threshold level during a first time period, wherein a difference in rates is determined by the input voltage signal, generating a differential voltage on a pair of nodes during the first time period by selectively controlling a respective amount of discharge of an initial charge on each node of the pair of nodes by applying the first and second discharge control signals to respective transistors in a differential transistor pair connected to the pair of nodes, and maintaining the differential voltage on the pair of nodes during a subsequent time period, and generating an amplified differential voltage during at least a portion of the subsequent time period by amplifying the differential voltage.

Efficient methods and recursive/scalable circuit architectures for QAM symbol mean and variance estimations
09917723 · 2018-03-13 · ·

Circuits for producing signals representative of mean and variance estimations for quadrature amplitude modulation (QAM) are provided where the circuits comprise: sequentially repeated first circuit modules and sequentially repeated second circuit modules configured for producing updates in the corresponding estimation iterations. In one embodiment, a closest negative integer power of 2 is used as a substitute multiplicand when multiplying together two or more outputs of hyperbolic function generating units where the substituted for output is less than one. Size and complexity of the corresponding multiplier can then be reduced.

METHOD AND AUXILIARY METHOD, APPARATUS, BASE STATION AND USER EQUIPMENT FOR INTERFERENCE CANCELLATION
20180019905 · 2018-01-18 · ·

The present disclosure provides a method for interference cancellation which includes: calculating a mean value and a variance value of a received signal to obtain statistics information of the received signal; calculating an estimating log-likelihood ratio using the statistics information of the received signal; calculating a decoding log-likelihood ratios of the received signal using the estimating log-likelihood ratio of the received signal, and performing calculations to update the statistics information of the received signal; repeating the above steps for a pre-determined number of times, performing hard decisions on the decoding log-likelihood ratios of the received signal, and outputting data bits obtained from the hard decision. The present disclosure also provides an apparatus, an auxiliary method, a base station and a terminal device for interference cancellation. The mechanism of the present disclosure can reduce the impact of inherent interference in the FBMC/OQAM system on system performances, and increase spectral efficiency and design flexibility of the FBMC/OQAM system.