Qualcomm Incorporated

Other

Farrokh Abrishamkar

Divaydeep Sikri

Yingqun Yu

Wenjun Li

Bahadir Canpolat

Raghu Narayan Challa

Shimman Arvind Patel

Michael Lee McCloud

Gilbert Christopher Sih

Serguei A Glazko

Insung Kang

Mark Roh

Ori Shental

Nico De Laurentiis

Ni-Chun Wang

Kenneth Kreutz-Delgado

John Edward Smee

Inyup Kang

Christopher Patrick

Way-Shing Lee

Byonghyo Shim

Ian J Fevrier

Ming Yan

Gil Sih

Sharad Deepak Sambhwani

Luca Blessent

Reza Shahidi

Brian Clarke Banister

Parvathanathan Subrahmanya

Brian K Butler

Roland Reinhard Rick

Keith William Saints

Yu-Chuan G Lin

Parisa Cheraghi

Thomas Wilborn

Prashant Udupa Sripathi

Matthias Brehler

Kartik B Ariyur

Thunyachate Ekvetchavit

Aditya Dua

James E Beckman

Mariam Motamed

Manish Jain

Joseph C Chan

Michael Leviant

Chao Jin

Erdogan Dede

Sheng-Yuan Tu

Jiangxin Chen

Surendra Boppana

Andrew K Kan

Seguei A Glazko

Ken Delgado

Manini Shah

Philip J C Children

Michael L Mccloud

A process of wireless communication for obtaining channel quality information alignment includes predicting a channel state of a future downlink subframe of a signal. The process also includes providing a base station with a set of parameters based on the predicted channel state. For example, a user equipment (UE) can obtain a recommended transport block size (RTBS) from the predictor process, and return the RTBS to the base station as one of the set of parameters.

Predicting channel state

The various embodiments include methods and apparatuses for canceling nonlinear interference during concurrent communication of multi-technology wireless communication devices. Nonlinear interference may be estimated using a multilayer perceptron neural network with Hammerstein structure by dividing an aggressor signal into real and imaginary components, augmenting the components by weight factors, executing a linear combination of the augmented components, and executing a nonlinear sigmoid function for the combined components at a hidden layer of multilayer perceptron neural network to produce a hidden layer output signal. At an output layer, hidden layer output signals may be augmented by weight factors, and the augmented hidden layer output signals may be linearly combined to produce real and imaginary components of an estimated jammer signal. A linear filter function may be executed for the components of the jammer signal, and to produce a nonlinear interference estimate used to cancel the nonlinear interference of a victim signal.

Methods and systems for multi-layer perceptron based non-linear interference management in multi-technology communication devices

Systems and methods of receiving data in a communication system are disclosed. The methods include equalizing a plurality of samples to suppress intersymbol interference and provide a first set of detected bits based on a first set of reference bits comprising a training sequence on a first iteration. The methods further include suppressing co-channel interference in the plurality of input samples and provide a set of suppressed samples based on a second set of reference bits comprising the first set of detected bits on a second iteration. The methods further include equalizing the set of suppressed samples to suppress intersymbol interference and provide a second set of detected bits based on the second set of reference bits on the second iteration.

Hybrid SAIC receiver

An apparatus and method for a two-stage linear/nonlinear interference cancellation comprising processing a receive signal to produce a first descrambled signal; and processing the first descrambled signal to produce a detected signal. In one aspect, a first interference canceller module is used for processing the received signal and a second interference canceller module is used for processing the first descrambled signal. In one aspect, the first interference canceller is a linear interference canceller (IC) and the second interference canceller is a linear/nonlinear interference canceller (IC).

Apparatus and method for two-stage linear/nonlinear interference cancellation

A novel symbol estimation method produces intersymbol interference free symbols by detecting interfering symbols in an interfering channel. A channel estimate is refined for additional improvements. The method can lends itself as a serial or parallel algorithm implementation. The symbol estimation method includes using an initial estimate of received symbols and calculating a refined estimate of the received symbols using a channel estimate. The refined estimate is calculated by performing parameterization of intersymbol interference by symbols other than the symbol being refined and selecting a refined value for the symbol being refined by evaluating an optimization function. Symbol estimates are refined in multiple iterations, until a predetermined iteration termination criterion is met. Parameterization of ISI contribution of other symbols results in reduced computation by reducing total number of unknown variables in the refinement operation.

Symbol estimation methods and apparatuses

Techniques for recovering a desired transmission in the presence of interfering transmissions are described. For successive equalization and cancellation (SEC), equalization is performed on a received signal to obtain an equalized signal for a first set of code channels. The first set may include all code channels for one sector, a subset of all code channels for one sector, multiple code channels for multiple sectors, etc. Data detection is then performed on the equalized signal to obtain a detected signal for the first set of code channels. A signal for the first set of code channels is reconstructed based on the detected signal. The reconstructed signal for the first set of code channels is then canceled from the received signal. Equalization, data detection, reconstruction, and cancellation are performed for at least one additional set of code channels in similar manner.

Successive equalization and cancellation and successive mini multi-user detection for wireless communication

A two stage interference cancellation (IC) process includes a linear IC stage that suppresses co-channel interference (CCI) and adjacent channel interference (ACI). The linear IC stage disambiguates otherwise super-trellis data for non-linear cancellation. Soft linear IC processing is driven by a-posteriori probability (Apop) information. A second stage performs expectation maximization/Baum Welch (EM-BW) processing that reduces residual ISI left over from the first stage and also generates the Apop which drives the soft linear IC in an iterative manner.

Soft linear and non-linear interference cancellation

The present disclosure presents methods and apparatuses for enhanced received signal processing using signal-based channel impulse response (CIR) estimation. For example, according to an example method presented herein, a user equipment (UE) or a component therein may receive a signal corresponding to a transmitted signal sent by a network entity, wherein the transmitted signal comprises at least a data channel, estimate chip contents of the transmitted signal, based on the received signal including the data channel, to obtain estimated chip contents, and compute an estimated channel impulse response (CIR) based on at least the estimated chip contents. Based on this estimated CIR, the UE may thereafter reprogram a received signal reconstruction filter, perform interference cancellation procedures, and/or adjust one or more equalizer taps. By performing such functions, the UE may exhibit improved communication characteristics and enable a more robust user experience.

Methods and apparatuses for enhanced received signal processing based on a data-signal-aided channel impulse response estimation

An interference cancellation receiver for a pre-coded orthogonal frequency division multiplexed (OFDM) based system combines temporal interference cancellation within the OFDM framework. Multi-path equalization and inter-symbol interference (ISI) cancellation are performed on a time domain channel estimate of a received signal. An output from the multi-path equalization is transformed to the frequency domain. Inter-channel interference (ICI) is performed in the frequency domain on an equalized signal from the multi-path equalization after transforming the equalized signal from the time domain to the frequency domain.

Advanced interference cancellation for precoded GSM edge radio access network (GERAN)

A method for timing and frequency synchronization in a wireless system is provided. The method comprises the steps of receiving a burst of symbols, selecting a subset of the burst of symbols, iteratively adjusting the subset of the burst of symbols by a plurality of timing offsets and calculating, for each timing offset, a first performance metric corresponding to the adjusted subset. The method further comprises the steps of determining one of the plurality of timing offsets to be a preferred timing offset based upon the first performance metric thereof, iteratively rotating the subset of the burst of symbols by a plurality of frequency offsets and calculating, for each frequency offset, a second performance metric corresponding to the rotated subset, and determining one of the plurality of frequency offsets to be a preferred frequency offset based upon the second performance metric thereof.

Interference cancellation under non-stationary conditions

An apparatus and method for channel estimation comprising obtaining a response matrix G(l) using Q quantity pilots; constructing a sensing matrix Wbased on K quantity tones, L quantity symbols and P quantity multipaths; and using compressive sensing channel estimation to determine an equivalent channel matrix G(i) based on the response matrix G(l) and the sensing matrix W.

Apparatus and method for channel estimation using compressive sensing

An apparatus and method for compressive sensing tap identification for channel estimation comprising identifying a set of significant taps in the time domain; representing a time-flat channel response using a Taylor series expansion with the set of significant taps; converting the time-flat channel response to a vectorized channel response; transforming the vectorized channel response to a compressive sensing (CS) polynomial frequency response; aggregating the CS polynomial frequency response into a stacked frequency response; converting the stacked frequency response into a measured pilot frequency response; estimating a channel parameter vector based on the measured pilot frequency response; and generating a reconstructed channel response from the channel parameter vector.

Apparatus and method for compressive sensing tap identification for channel estimation

Techniques for deriving a channel estimate using a scattered pilot and a continual pilot are described. The scattered pilot is sent on different sets of carriers in different symbol periods. The continual pilot is sent in each symbol period on irregularly spaced carriers. The scattered pilot is used to identify the indices of channel taps of interest, e.g., L strongest channel taps. The continual pilot is used to determine the complex gains of these L channel taps. A receiver derives a channel impulse response estimate based on received pilot symbols for the scattered pilot, identifies the L strongest channel taps, and determines the indices of these L strongest channel taps. The receiver forms a Fourier sub-matrix based on the L tap indices and determines the gains of the L channel taps based on received pilot symbols for the continual pilot and the Fourier sub-matrix.

Channel estimation for multi-carrier communication

A multi-stage interference suppression receiver includes a short equalizer section configured to operate on a first portion of a received signal received over a channel to produce a first equalized signal and a first estimate of the channel, a channel estimator section configured to operate on the first equalized signal to produce a second equalized signal, the channel estimator section comprising a linear estimator and a non-linear estimator, a long equalizer section configured to operate on a second portion of the received signal to produce a first estimate of symbols in the received signal and a second estimate of the channel and an interference canceller section configured to operate on the first estimate of symbols in the received signal to generate a second estimate of symbols in the received signal based on, at least in part, the second estimate of the channel.

Multi-stage interference suppression

Systems and methods for multi-user detection are provided. In one aspect of the disclosure, an apparatus is provided. The apparatus comprises a processing unit configured to process a plurality of received chips into a plurality of received symbols for a plurality of users. The apparatus further comprises a computation unit configured to compute a multi-user matrix relating a plurality of user symbols for the plurality of users to the plurality of received symbols and a detection unit configured to detect the plurality of user symbols for the plurality of users using the computed multi-user matrix and the plurality of received symbols.

Method and system for multi-user detection using two-stage processing

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San Diego, CA, United States of America

Farrokh Abrishamkar