Qualcomm Incorporated

Pinar Sen

Tingfang Ji

Naga Bhushan

Seyong Park

Krishna Kiran Mukkavilli

Renqiu Wang

Hwan Joon Kwon

Peter S Gaal

Muhammad Sayed Khairy Abdelghaffar

Abdelrahman Mohamed Ahmed Mohamed Ibrahim

Jing Jiang

Wei Jennifer Yang

Wei Yang

Joseph Binamira Soriaga

Gabi Sarkis

Thomas J Richardson

Jay Kumar Sundararajan

Danlu Zhang

Yongjun Kwak

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.

Techniques for estimating misalignment between multiple antenna arrays

The present disclosure describes the generation of long sequences from short sequences to support concurrent transmissions of large numbers of machine-type communication devices operating in a wireless communication system. These long sequences may be assigned to devices so that the devices can use the long sequences scramble their transmissions. The use of such long sequences permits many machine-type communication devices to transmit during the same time and frequency resource.

Sequence generation and assignment

Methods, systems, and devices for wireless communications are described. A first wireless device may receive a request for beamforming information associated with line-of-sight (LoS) multiple input multiple output (MIMO) communication from a second wireless device. The first wireless device may generate a channel estimation matrix for a channel between rectangular antenna arrays of the respective wireless devices, the channel estimation matrix including one or more quadratic terms for the LoS MIMO communication. The first wireless device may generate a first sub-matrix and a second sub-matrix based on the channel estimation matrix. The first wireless device may transmit an indication of a set of precoders for the LoS MIMO communication, the set of precoders based on a symmetry associated with the first and second sub-matrices, and may receive the LoS MIMO communication from the second wireless device based on the set of precoders.

Techniques for line-of-sight MIMO communications using rectangular antenna arrays

Methods, systems, and devices for wireless communications are described. A UE may use different modulation schemes, or different modulators, for a single data stream. The set of modulators may be based on a linear combination of a function of encoded bits to be transmitted. In some cases, the UE may use a different permutation or interleaving of the function of bits with the same linear function to generate a different set of modulators. The UE may use a combination of any one or more of the described techniques for generating a set of modulators. Different modulators may be cyclically repeated over time. The UE may apply a device-specific scrambling sequence and transmit the modulated symbols on an uplink channel. The base station may use matched filters and an element-wise estimator (ESE) to compute log-likelihood ratios (LLRs) for each bit of each UE in a received signal.

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San Diego, CA, United States of America

Pinar Sen