Qualcomm Incorporated

Xcom Labs, Inc.

Apple Inc.

Virewirx, Inc.

Wanlun Zhao

Peter J Black

Jinghu Chen

Tamer Adel Kadous

Michael Mingxi Fan

Fuyun Ling

Qiang Wu

Parag Arun Agashe

Ayman Fawzy Naguib

Roberto Padovani

Yeliz Tokgoz

Pranav Dayal

Je Woo Kim

Stephen William Edge

Mingxi Fan

Naga Bhushan

Krishna Kiran Mukkavilli

Jing Jiang

Jia Tang

Parvathanathan Subrahmanya

Peter John Black

Weihong Jing

This disclosure relates to techniques for reducing blind decoding of downlink control channels in a wireless communication system. The techniques may include determining whether a control channel pilot signal, such as a demodulation reference signal (DMRS) is present within a set of control carrier entities, and accordingly determining whether the downlink control channel is present within the set of control channel elements. In this manner, a number of candidates for blind decoding may be reduced.

NR control channel element detections to reduce blind demodulation and decoding

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

Briefly, in accordance with one embodiment, a method of transmitting signals is provided. Signal waveforms are transmitted from at least two respective sectors. The at least two respective sectors are from at least two different sets of a superset of sectors. The transmitted signal waveforms include signal waveforms at least nearly mutually orthogonal at least along a particular signal dimension. An advantage of such an embodiment, for example, is reduced signal interference.

Positioning using enhanced pilot signal

Enhanced pilot signal

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

An improved receiver apparatus and algorithm for equalizing signals in a receiver device may equalize a block of data generated from N data symbols in a single carrier communication system. A first algorithm may be applied to a plurality of signal samples to generate a frequency domain representation of the samples. A channel estimate may be generated and a frequency response of a zero-forcing or a minimum-mean-square equalizer is applied. A conjugate of the computed frequency response is multiplied with a frequency domain representation for each sample to generate a product value. N-aliased frequency domain values from the generated product value may be determined for each of the samples. A second algorithm is applied to the generated N-aliased frequency domain values to generate estimates of the transmitted time domain data symbols.

Methods and systems for optimal zero-forcing and MMSE frequency domain equalizers for complex and VSB signals

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

Briefly, in accordance with one embodiment, a method of adjusting for digital automatic gain control (DAGC) quantization error in a mobile station is as follows. A first DAGC value is stored before reception of one or more enhanced pilot signals. A second DAGC value is computed during reception of the one or more enhanced pilot signal. The first DAGC value is restored after reception of the one or more enhanced pilot signals is over. An advantage associated with this particular embodiment may include reduction in quantization error for digital automatic gain control.

Growing community of inventors

San Diego, CA, United States of America

Wanlun Zhao