Qualcomm Incorporated

Xcom Labs, Inc.

Mediatek Singapore Pte. Ltd.

Virewirx, Inc.

Jinghu Chen

Wanlun Zhao

Peter J Black

Tamer Adel Kadous

Michael Mingxi Fan

Joseph Binamira Soriaga

John Edward Smee

Jilei Hou

Fuyun Ling

Mingxi Fan

Naga Bhushan

Krishna Kiran Mukkavilli

Jing Jiang

Jia Tang

Wei-De Wu

Chia-Wei Tai

Jiye Liang

Navid Hassanpour Ghady

Peter John Black

Weihong Jing

Hsiang Sheng Hu

Aspects of this disclosure relate to a time-division duplex (TDD) multiple-input multiple-output (MIMO) system that includes a plurality of nodes. The plurality of nodes collectively includes antennas divided into groups. Reference signals can be transmitted from each group of antennas to one or more other groups of antennas during respective time slots. Channel estimates can be generated based on the received reference signals. The channel estimates can be jointly processed to generate calibration coefficients. Each calibration coefficient can represent a ratio associated with a transmit coefficient and a receive coefficient. Example algorithms for the joint processing are disclosed.

Time-division duplex multiple-input multiple-output calibration

Aspects of this disclosure relate to reference signal channel estimation. A wireless communication channel between two nodes can be estimated based on a received reference signal, such as a Sounding Reference Signal. Techniques are disclosed to improve performance of reference signal channel estimation and make channel estimates more robust in the presence of one or more of a variety of impairments. Frequency domain processing and/or time domain processing can be performed to reduce distortion in channel estimates.

Reference signal channel estimation

Time-division duplex multiple input multiple output calibration

Aspects of the disclosure relate to a selection scheme implemented by a scheduler in a multiple-input multiple-output (MIMO) network to identify which users to schedule simultaneously during the same time slot. For downlink communications and a particular frequency wholeband or sub-band, the scheduler can determine downlink channel information using uplink channel information for channels between base stations and UEs. The scheduler can then determine a strength of the channels using the downlink channel information, order the UEs using a fairness metric based on the channel strengths, and compute one or more QR decompositions to identify whether a spatial dimension of a UE is roughly or approximately orthogonal to spatial dimension(s) of other UEs selected to be served during a time slot being scheduled. If the spatial dimensions are roughly or approximately orthogonal, the scheduler selects the UE to be served at the same time as other UEs already selected.

Downlink user equipment selection

Aspects of the disclosure relate to a selection scheme implemented by a scheduler in a multiple-input multiple-output (MIMO) network to identify which users to schedule simultaneously during the same time slot. For uplink communications and a particular frequency wholeband or sub-band, the scheduler can obtain uplink channel information for channels between base stations and UEs. The scheduler can then determine a strength of the channels using the uplink channel information, order the UEs using a fairness metric based on the channel strengths, and compute one or more QR decompositions to identify whether a spatial dimension of a UE is roughly or approximately orthogonal to spatial dimension(s) of other UEs selected to be served during a time slot being scheduled. If the spatial dimensions are roughly or approximately orthogonal, the scheduler selects the UE to be served at the same time as other UEs already selected.

Uplink user equipment selection

A signal processing device for communication is provided and includes a de-rate matching module, a decoder, a signal-quality generation module, and a first control module. The de-rate matching module performs a de-rate matching operation on the control signal to obtain a de-rate matching signal. The decoder performs a decoding operation on the de-rate matching signal to obtain a decoding signal. The signal-quality generation module generates at least one signal-quality indicator according to the control signal and the de-rate matching signal. The at least one signal-quality indicator includes a similarity indictor which is obtained by the signal-quality generation module performing a similarity calculation operation on the control signal and the de-rate matching signal. The first control module determines and controls whether to stop the decoding operation for the de-rate matching signal of the current control signal according to the at least one signal-quality indicator.

Signal processing devices and methods

A method of wireless communication includes receiving a wireless signal at a linear receiver, and iteratively computing an inverted covariance matrix in frequency domain, one channel code at a time. The method also includes computing receiver demodulation coefficients based on the inverted covariance matrix and the frequency domain channel estimate or time domain channel estimate. The method further includes deriving a transmitter symbol based on a received signal vector and the coefficients.

Iterative covariance inversion based on linear receiver designs

The present disclosure describes methods and apparatuses for improved transport block decoding in devices capable of wireless communication, which may include user equipment and network entities. For example, the present disclosure presents methods and apparatuses for decoding a code block from a plurality of code blocks corresponding to a transport block, obtaining a reliability indicator that identifies a reliability of the decoding of the code block, comparing the reliability indicator to a reliability threshold, and determining whether to decode a subsequent code block from the plurality of code blocks based on the comparing. Furthermore, these methods and apparatuses may include determining not to decode at least one subsequent code block of the transport block where the comparing indicates that the reliability indicator is less than the reliability threshold. As such, device power is not unnecessarily consumed by decoding likely superfluous code blocks.

Methods and apparatuses for saving power during transport block decoding in UMTS systems

Certain embodiments provide methods that may allow for improvements in performance and power consumption by terminating the turbo decoding process early when one of at least two test criterion is satisfied in communications systems, including UMTS, WCDMA, and TD-DCMA.

Early termination schemes for turbo decoding in a wireless communication system

Methods and systems for adjusting a forward link (FL) signal to interference and noise ratio (SINR) are provided. In an example, a FL SINR is estimated for each user in a plurality of users, on at least one of each user's respective data rate control (DRC) message or each user's respective prior FL SINR value. The respective estimated FL SINR for a user in the plurality of users is increased, if, based on a reverse link acknowledge message, the user has decoded a packet before all symbols in the packet have been transmitted. Remaining control channel power is determined. The estimated FL SINR for all users in the plurality of users is increased if remaining control channel power is less than a low threshold. The estimated FL SINR for all users in the plurality of users is increased if the remaining control channel power is greater than a high threshold.

Methods and apparatus for adjusting forward link signal to interference and noise ratio estimates

A method of wireless communication is disclosed that includes receiving detected channel information from a plurality of access terminals; selecting a set of access terminals from the plurality of access terminals based on the received channel information; creating a beamforming vector for each access terminal in the set of selected access terminals; and transmitting a signal using at least one of the created beamforming vectors. An apparatus for performing the method is also disclosed herein.

Method and apparatus for facilitating multi-user joint transmit-receive beamforming

A system and method for Interference Cancellation (IC). One aspect relates to iterative interference cancellation with iterative finger delay adaptation. The interference cancellation method comprises receiving multi-paths of a signal; and performing iterative interference cancellation to remove multi-path interference, wherein the performing iterative IC comprises estimating a Signal-to-Interference-plus-Noise Ratio (SINR) at each of a plurality of pre-determined rake receiver finger delays, and performing successive Channel Estimation (CE) and IC on rake receiver fingers according to their estimated SINRs, and wherein the CE of a next finger does not start until interference of a previous finger is removed from a sample buffer. The method may further comprise improving estimated rake receiver finger delay, and each iteration decreases the amount of interference observed by each finger.

Iterative interference cancellation system and method

A method and system for reconstructing a user's received signal based on knowledge of the user's transmitted signal to yield efficient interference cancellation when there is spatial and/or temporal correlation in the received signal. The invention may be applied to the cancellation of pilot, decoded data and overhead signals. The method may involve a linear combination of the received samples across time, e.g., at a per-chip or sub-chip resolution, and across antennas, and build upon previous work in that the tap weights need not be the sole functions of the de-spreader outputs in the RAKE receiver.

Growing community of inventors

San Diego, CA, United States of America

Jinghu Chen