Qualcomm Incorporated

Pinar Sen

Tingfang Ji

Naga Bhushan

Seyong Park

Krishna Kiran Mukkavilli

Renqiu Wang

Muhammad Sayed Khairy Abdelghaffar

Hwan Joon Kwon

Peter S Gaal

Abdelrahman Mohamed Ahmed Mohamed Ibrahim

Jing Jiang

Yu Zhang

Danlu Zhang

Wei Yang

Alexandros Manolakos

Wei Jennifer Yang

Yongjun Kwak

Runxin Wang

Joseph Binamira Soriaga

Gabi Sarkis

Juergen Cezanne

Mahmoud Taherzadeh Boroujeni

Thomas J Richardson

Jay Kumar Sundararajan

Amira Alloum

Certain aspects relate to techniques for estimating and compensating for antenna array rotation of a wireless node. For example, the antenna array of the wireless node may rotate about one or more of an x-axis, a y-axis, and a z-axis, which may misalign the antenna array relative to another antenna array of another wireless node, causing degradation of communications between the two nodes. In some examples, the wireless node may obtain, from a first antenna array of the other wireless node via a second antenna array of the first wireless node, a first pilot signal and a second pilot signal via a first beam. In some examples, the first wireless node may perform a first alignment compensation based on a phase difference between the first pilot signal and the second pilot signal.

Estimating and compensating antenna array misalignment

Methods, systems, and devices for wireless communications are described. A transmitted may use a closed loop precoder for line-of-sight (LOS) multiple-input multiple-output (MIMO) communications that uses information such as distance feedback or LOS MIMO channel state feedback. A closed loop precoder may be associated with less overhead than a precoder based on full channel knowledge, such as an SVD precoder. A receiver may estimate a channel based on channel state information reference signals transmitted by the transmitter and calculate a spectral efficiency for one or more precoders of a set of precoders associated with the channel for a LOS MIMO mode. The receiver may send feedback to the transmitter that indicates a selected precoder of the set of LOS MIMO precoders based on the calculated spectral efficiencies. The transmitter may precode messages using the reported closed loop precoder.

Method and apparatus for codebook design for closed loop operation

Methods, systems, and devices for wireless communications are described. A user equipment (UE) generates multiple systematic bits for a message, where the systematic bits are nonuniformly distributed over a time period such that a first bit value has a first probability of occurrence during the time period and a second bit value has a second probability that is greater than the first probability of the occurrence. The UE modulates the systematic bits according to an asymmetric modulation rule such that the first bit value corresponds to a first constellation point on a constellation graph and the second bit value corresponds to a second constellation point that is relatively closer to a center of the constellation graph than the first constellation point based on the second probability being greater than the first probability. The UE transmits the message including systematic bits modulated according to the asymmetric modulation rule.

Communicating nonuniform sources using systematic codes

Aspects for time bundling an SRS resource over a plurality of instances are disclosed. The apparatus may include a user equipment (UE). The user equipment may receive a configuration from a base station for time-bundling at least one sounding reference signal (SRS) resource. The time-bundling may be performed by the UE transmitting a plurality of SRS signals at different times using an identical center frequency and at least two different frequency resource allocations. The UE may transmit the plurality of SRS signals based on the configuration.

Sounding reference signal (SRS) time bundling for partial frequency sounding

Aspects of the disclosure relate to the use of enhanced downlink control information to communicate partial frequency sounding configuration to user equipment (UE). A UE may receive a partial frequency sounding configuration generated for the UE the downlink control information, transmit a sounding reference signal (SRS) in one or more resources configured for SRS transmission in a bandwidth used by the UE, the one or more resources being identified by the partial frequency sounding configuration, and refrain from transmitting in a portion of a set of resources configured for SRS transmission in the bandwidth used by the UE. A format for the enhanced downlink control information may be based on standards defined the downlink control information formats.

Group common downlink control information enhancements for partial frequency sounding of multiple UEs

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive control signaling indicating a demodulation reference signal (DMRS) configuration for an uplink message that may indicate for the UE to refrain from including DMRS in at least a first portion of the uplink message based on the DMRS configuration. The UE may encode the uplink message without the DMRS in at least the first portion of the uplink message in accordance with the DMRS configuration. The UE may transmit the uplink message based on encoding the uplink message, and a network entity may receive and decode the uplink message. In some examples, the network entity may receive signaling that includes a set of uplink messages from different UEs. As such, the network entity may decode each, using a respective Reed-Muller (RM) code in accordance with a multi-user decoding algorithm.

Demodulation reference signal configuration for uplink messages

Methods, systems, and devices for wireless communications are described. A transmitting device may perform a lifting procedure on a base graph including multiple variable nodes and multiple check nodes to obtain a lifted graph. The lifting procedure may include replacing each edge between multiple variable nodes and multiple check nodes of the base graph with a respective identity matrices with respective circular shift values. The base graph may include a punctured variable node which corresponds to each of one or more check nodes of the plurality of check nodes via multiple edges. The transmitting device may encode multiple information nodes and multiple parity nodes according to the lifted graph. The transmitting device may transmit a signal including multiple information bits and multiple parity bits based on encoding the multiple information nodes and the multiple parity nodes.

Fast converging low-density parity-check techniques

An apparatus for wireless communication is provided. The apparatus may be a network node. The apparatus receives a set of uplink transmissions from a set of user equipments (UEs) via a first resource of a non-orthogonal channel, wherein the apparatus is unable to decode the set of uplink transmissions. The apparatus transmits a retransmission request to a subset of the set of UEs. The apparatus receives a retransmission of a first uplink transmission in the set of uplink transmissions via a second resource of the non-orthogonal channel in response to the retransmission request. The apparatus decodes a second uplink transmission in the set of uplink transmissions based on at least the retransmission of the first uplink transmission.

Selective retransmissions on a non-orthogonal channel

Certain aspects relate to techniques for z-axis rotation estimation for compensating signaling transmitted between two or more nodes over a wireless channel where an antenna array of at least one of the nodes is misaligned about the z-axis relative to another node. For example, a transmitting node may transmit pilot signals defined by phase shifts to provide a receiving node with a basis for estimating the angle of rotation by which the antenna arrays are misaligned. The transmitting node may then take remedial action to address the misalignment based on the estimation.

Signaling for z-rotation estimation

Methods and apparatuses for wireless communication for line-of-sight Multiple-Input-Multiple-Output (LOS MIMO) are described. A first pilot signal is transmitted to a second device. The first pilot signal is at least one of a constant phase pilot or a linear phase ramped pilot for estimating a misalignment of a second antenna array of the second device with respect to a first antenna array of the first device.

Parallel shift estimation for LOS MIMO communication

Methods, systems, and devices for wireless communications are described. A first wireless device may be configured to transmit one or more reference signals to a second wireless device using a first antenna array at the first wireless device and in accordance with a first precoder matrix. The first wireless device may receive, from the second wireless device based on the one or more reference signals, a feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The first wireless device may then transmit a message to the second wireless device in accordance with a second precoder matrix that is modified relative to the first precoder matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

Techniques for estimating misalignment between antenna arrays

Methods, systems, and devices for wireless communications are described. In some examples, a transmitting device may generate a parity check matrix based on performing a lifting operation on a base matrix. Each column of the base matrix may correspond to a different variable node and each row may correspond to a different check node. The transmitting device may then generate a set of coded bits based on the parity check matrix and each coded bit of the set of coded bits may be associated with a respective variable node. Further, the transmitting device may interleave the set of coded bits such that subsets of the set of coded bits associated with a same variable node are mapped to a same channel reliability level and transmit the set of coded bits according to the interleaving.

Techniques for mapping coded bits to different channel reliability levels for low density parity check codes

An antenna offset compensation determination method includes: transmitting, from a first apparatus to a second apparatus, one or more first signals from a first plurality of antenna elements, of a first antenna of the first apparatus, and one or more second signals from a second plurality of antenna elements, of the first antenna; receiving, at the first apparatus from the second apparatus, one or more first indications of a first linear offset of a first signal distinction line relative to a second antenna of the second apparatus, the first signal distinction line corresponding to a first transition between the one or more first signals and the one or more second signals as received by the second antenna; and determining, based on the first linear offset, one or more compensation parameters for compensating for the first linear offset.

Parallel shift estimation

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may generate a Legendre precoder for transmission on a multiple-input multiple-output channel based at least in part on computing Legendre polynomials for a quantity of transmit antennas. The wireless communication device may transmit a communication using the Legendre precoder. Numerous other aspects are provided.

Generation of spatial multiplexing modes for multiple input multiple output channel

Methods, systems, and devices for wireless communications are described. A first wireless device may identify a translational or rotational misalignment between a first antenna array of the first wireless device and a second antenna array of a second wireless device that is in line-of-sight (LoS) wireless communication with the first wireless device via a channel. The first wireless device may update a channel matrix for the channel based on the translational or rotational misalignment, where the first wireless device may update the channel matrix with one or more beam steering metrics of the first antenna array so as to improve a beam alignment between the first antenna array and the second antenna array. The first wireless device may communicate with the second wireless device in accordance with the updated channel matrix.

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San Diego, CA, United States of America

Pinar Sen