Qualcomm Incorporated

Hendrik Schoeneich

Tao Luo

Taesang Yoo

Myriam Rajih

Lu Zhao

Juan Montojo

Yongbin Wei

Durga Prasad Malladi

Stefan Brueck

Shay Landis

Assaf Touboul

Siddhartha Mallik

Ran Berliner

Christoph A Joetten

Marc W Werner

Andreas Maximilian Schenk

Armin Dekorsy

Muhammad Awais Amin

Krishna S Pandit

Stephan Schlupkothen

Michael Paul Cyran

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE configured to receive a plurality of beams through a plurality of different receive beam directions, each of the beams including broadcast information on a PBCH. The apparatus may be further configured to determine, for each of a subset of the received beams, a log likelihood ratio (LLR) for coded bits of the broadcast information. The apparatus may be further configured to decode the broadcast information associated with each of the subset of the received beams, and determine a refined receive beam direction based on the determined LLRs and based on whether the broadcast information associated with each of the subset of the received beams fails to decode or is successfully decoded.

Methods and apparatus related to beam refinement

In order to cancel any interference due to the second signal (e.g., from a non-serving cell) from a signal received at a UE, without receiving additional control information, the UE blindly estimates parameters associated with decoding the second signal. This may include determining a metric based on sets of symbols associated with the signals in order to determine parameters for the second signal, e.g., the transmission mode, modulation format, and/or spatial scheme of the second signal. The parameters for the signal may be determined based on a comparison of the metric with a threshold. When a spatial scheme and a modulation format is unknown, the blind estimation may include determining a plurality of constellations of possible transmitted modulated symbols associated with a potential spatial scheme and modulation format combination. Interference cancellation can be performed using the constellations and a corresponding probability weight.

Method and apparatus for interference cancellation by a user equipment using blind detection

Communications by base stations in wireless communication networks may be coordinated in a manner to improve performance by mobile devices experiencing interference from non-serving base stations. In particular, base station communications may be coordinated to improve the performance of interference cancellation by mobile devices. If a user equipment (UE) experiencing interference is capable of interference cancellation, then the base stations may coordinate to increase interference to that user equipment so as to improve that UE's ability to perform interference cancellation. Base stations may also coordinate to reduce interference for a UE, regardless of the UE's ability to perform interference cancellation. Mobile device performance improvements may also be achieved by coordinating scheduling of resources by the non-serving base stations, by using communication formats compatible with interference cancellation, by spatial coordination.

Network coordination for improved interference cancellation

A method of performing channel estimation includes receiving a frame that includes, for each subcarrier of a subset of subcarriers in the frame, a pair of pilot symbols in the subcarrier. The subcarriers of the subset are regularly spaced apart from one another in the frequency domain. Time-averaged channel estimates for each subcarrier of the subset are generated based on the pairs of pilot symbols. Frequency-averaged channel estimates for respective subcarriers are generated based on the time-averaged channel estimates. Interpolation is performed between respective frequency-averaged channel estimates to generate interpolated channel estimates for subcarriers between the respective subcarriers.

Channel estimation using averaging and interpolation

A receiver circuit, including a multi-stage QAM de-mapper, for receiving a QAM data signal is disclosed. A first de-mapper circuit recovers a set of encoded data bits from the QAM data signal by calculating a plurality of distances between a received QAM symbol and each of a plurality of possible constellation points. A second de-mapper circuit then generates a set of unencoded data bits for the received QAM symbol based, at least in part, on the plurality of distances calculated by the first de-mapper circuit. The receiver circuit may further include a decoder circuit to decode the set of encoded data bits recovered by the first de-mapper circuit. The second de-mapper circuit may identify a subset of the plurality of possible constellation points based on a result of the decoding and select a constellation point that is associated with the shortest distance of the plurality of distances.

Enhanced decoding and demapping method and apparatus for QAM data signals

Certain aspects of the present disclosure relate to a hybrid approach for Physical Downlink Shared Channel (PDSCH) Interference Cancellation (IC). In certain aspects, if the PDSCH information is known for a serving cell but not be known for interfering cell(s), a hybrid approach that involves using Codeword-level IC (CWIC) for the serving cell and using Symbol-level IC (SLIC) for the interfering cells may be used for better IC performance. The hybrid IC approach may start with a UE attempting to decode the serving cell PDSCH. If the decode is unsuccessful, the UE may perform CWIC for the serving cell followed by SLIC using the results of the CWIC stage. After the SLIC stage, the UE may attempt to decode the serving cell PDSCH again. The UE may perform multiple operations of this method until the serving cell PDSCH is successfully decoded or a maximum number of iterations is reached.

Hybrid approach for physical downlink shared channel (PDSCH) interference cancellation

A system for wireless communication reduces implementation complexity for symbol level interference cancellation as applied to physical control and data channels, such as the physical downlink shared channel (PDSCH) and physical downlink control channel (PDCCH). A user equipment (UE) categorizes tones of a signal into tone groups. A different noise whitening matrix is applied to each tone group for demodulation and decoding of the signal.

Reducing complexity for implementing interference cancellation applied to physical channels of a wireless network

A method for determining an optimal access network by an apparatus is described. The method may include communicating with a first base station as part of a first access network using a first radio access technology (RAT). Information about access networks available to the apparatus may be received from a mobile broker. An optimal access network and the corresponding optimal RAT may be selected based on the received information. The method may also include switching to communications with a second base station using a second RAT.

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Heroldsberg, Germany

Hendrik Schoeneich