Telefonaktiebolaget Lm Ericsson (Publ)

Apple Inc.

Jianguo Long

Yongquan Qiang

Hong Ren

Shaohua Li

Xixian Chen

Girum Fantaye

Chandra Sekhar Bontu

Hua Xu

Bo Göransson

Shiguang Guo

Mats Åhlander

Ping Yu

Ahmed Nouah

James Jianfeng Weng

Mercy George

Sebastian Faxér

Karl D Mann

Patrick Lie Chin Cheong

Akram Bin Sediq

Guoqiang Lu

Israfil Bahceci

Alireza Mirzaee

Ali Afana

Wei Wang

Roger Mah

Ying Shao

Michel Chauvin

Michael Roger

Donald Brinkhurst

Chaocheng Tu

James Jinfeng Weng

Girum Alebachew Fantaye

A method, network node and wireless device (WD) for dual codebook configuration and channel state information (CSI) combining for large scale active antenna systems (AAS) are disclosed. According to one aspect, a method in a network node includes triggering the WD to transmit in succession or simultaneously, a horizontal CSI report reporting a horizontal CSI set for a horizontal direction of the array and a vertical CSI report reporting a vertical CSI set for a vertical direction of the array, the horizontal CSI set being mapped to a row of the array and the vertical CSI set being mapped to a column of the array. The method also includes receiving the horizontal and vertical CSI reports from the WD, and combining the horizontal and vertical CSI sets into a combined CSI set for at least one of scheduling and beamforming.

Dual codebook configuration and CSI combining for large scale active antenna systems

Embodiments of the present disclosure provide methods, apparatuses, and computer products for base station antenna calibration. A method is implemented in a base station for a cellular communications system. The method includes selecting, from a plurality of User Equipments, UEs, assistant UEs to assist the base station with antenna calibration, wherein selecting the assistant UEs is based upon criteria that includes UE channel state information, CSI, from the UEs; one or more uplink channel characteristics of an uplink channel from the UEs to the base station; a UE capability of the UEs, UE traffic information related to the UEs; and any combination thereof. A further step is obtaining antenna calibration assistance information from the assistant UEs, the antenna calibration assistance information being information that is used by the base station for antenna calibration.

UE selection for UE aided antenna calibration

A method and network node for timing error estimation and compensation for Fifth Generation (5G) New Radio (NR) downlink (DL) systems with uncalibrated antennas are provided. According to one aspect, a method in a network node includes transmitting a first Channel State Information Reference Signal (CSI-RS) having a first timing compensation and transmitting a second CSI-RS having a second timing compensation, receiving a CSI-RS resource indicator (CRI) in a CSI report from a wireless device (WD), and determining from the CRI which of the first and second timing compensation results in a greater spectrum efficiency.

Timing error estimation/compensation for 5G NR downlink systems with uncalibrated antennas

Methods and apparatuses for time-domain beam-sweeping are disclosed. In one embodiment, a method implemented in a wireless device (WD) includes receiving a CSI report configuration, the CSI-RS resource configuration and the CSI report configuration mapping each of a plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource to a corresponding CSI report; receiving at least one of the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource; and transmitting at least one CSI report according to the mapping. In another embodiment, a method in a network node includes determining a CSI-RS resource configuration for one CSI-RS resource; determining a CSI report configuration; and transmitting the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource according to the mapping.

Methods and apparatuses for time-domain beam-sweeping

Methods and systems for mitigating channel quality indication (CQI) saturation in a channel state information (CSI) report received from a wireless device (WD) are disclosed. In one or more embodiments, a WD is provided. The WD includes processing circuitry configured to mitigate channel quality indication (CQI) saturation in a CSI report to a network node by at least in part receiving configuration information comprising any one or more of: a power offset value, a number of channel state information reference signal, CSI-RS, ports, and a rank restriction. The WD then generates the CSI report such that the CSI report comprises a CQI value based at least in part on the received configuration information and optionally causes transmission of the CSI report.

CQI saturation mitigation in downlink massive MU-MIMO systems

Embodiments of the present disclosure provide methods and apparatuses for base station antenna calibration. A method is implemented in a base station for a cellular communications system. The method includes configuring a user equipment, UE, for a plurality of channel state information, CSI, reports associated to respective CSI reporting bands, the respective CSI reporting bands being either: (a) different subsets of sub-bands within a downlink bandwidth of the base station or (b) different downlink bandwidth parts served by the base station; receiving the CSI reports from the UE; estimating phase and delay errors for a plurality of transmit antenna branches of the base station; compensating for the estimated phase and delay errors for the transmit antenna branches based on the CSI reports received from the UE; and transmitting a downlink signal while compensating for the estimated phase and delay errors for the transmit antenna branches of the base station.

UE aided antenna calibration

According to one aspect, a network node configured to communicate with a wireless device is provided. The network node includes processing circuitry configured to: transmit a plurality of beamformed reference signals, each of the plurality of beamformed reference signals being associated with a respective sector of a cell; receive at least one uplink signal from the wireless device; select one of the plurality of beamformed reference signals for the wireless device to monitor based at least in part on the received at least one uplink signal; and transmit an indication configured to cause the wireless device to monitor the selected one of the plurality of beamformed reference signals.

Performance improvement for UE with limited CSI-RS capability via reciprocity based sector selection

According to certain embodiments, a method for use in a network node for constructing an unsounded channel in a wireless network wherein the network node comprises more antennas than a wireless device and the wireless device comprises more than one receive antenna comprises: receiving channel state information (CSI) feedback and a sounded reference signal from the wireless device; estimating a sounded channel from the sounded reference signal; deriving a partial downlink channel based on the sounded reference signal; constructing an unsounded channel as a function of the CSI feedback and the partial downlink channel; concatenating the sounded channel and unsounded channel into a full channel; and transmitting a wireless signal to the wireless device using the full channel for beamforming or link adaptation.

Channel construction for unsounded MIMO channel

According to one or more embodiments, a wireless device configured to report one of a plurality of predefined Channel Quality Indicator (CQI) values is provided. A maximum CQI value of the plurality of predefined CQI values corresponds to any one of a plurality of signal characteristic values greater than or equal to a threshold signal characteristic value. The wireless device includes processing circuitry configured to determine a first signal characteristic value associated with a received signal. The processing circuitry is further configured to if the first signal characteristic value is greater than or equal to the threshold signal characteristic value associated with the maximum CQI value, generate a CQI report indicating: the maximum CQI value, and a power backoff from the first signal characteristic value that results in the threshold signal characteristic value.

Channel quality indicator (CQI) reporting with CQI headroom

Systems and methods are disclosed herein for multi-user pairing and, in some embodiments, Signal to Interference plus Noise Ratio (SINR) calculation in a cellular communications system. In some embodiments, a method performed in a base station of a cellular communications system to perform downlink scheduling for Multi-User Multiple Input Multiple Output (MU-MIMO) comprises, for each User Equipment (UE) of a plurality of UEs considered for MU-MIMO UE pairing, obtaining a relative beam power at the UE for each of the plurality of beams. The relative beam power at the UE for each beam is a value that represents a relative beam power of the beam at the UE relative to a beam power of a strongest of the plurality of beams at the UE. The method further comprises selecting a MU-MIMO UE pairing based on the obtained relative beam powers.

Multi-user pairing and SINR calculation based on relative beam power for codebook-based DL MU-MIMO

Apparatuses and methods are disclosed for Channel State Information Reference Signal (CSI-RS) resource mapping. According to one embodiment, a method in a network node includes allocating at least one resource for CSI Interference Measurement (CSI-IM) within a predetermined IM region of a Resource Block (RB) of the cell, the predetermined IM region encompassing a plurality of resources of the RB of the cell, the allocated at least one resource being selected from among the plurality of resources of the IM region to reduce a likelihood of overlap with at least one resource allocated for CSI-IM in a neighboring cell, the predetermined IM region at least partially overlapping with a respective predetermined IM region of a RB of the neighboring cell, and the predetermined IM region of the cell not overlapping resources allocated for Non-Zero Power Channel State Information Reference Signal (NZP CSI-RS) of the neighboring cell.

Channel state information reference signal resource mapping

A method, network node and wireless device for phase error compensation for Fifth Generation downlink systems with four correlated uncalibrated antennas are provided. A method includes applying N incremented phase rotations to one of the four antennas to produce N channel state information reference signal resources, N being an integer greater than 1. The method also includes transmitting N CSI-RS on 4 CSI-RS ports to a wireless device, WD, each of the N CSI-RS resources being transmitted with a different one of the incremented phase rotations. The method further includes receiving from the WD a CSI-RS resource indication that indicates a particular one of the N CSI-RS resources. The method also includes applying, in subsequent transmissions to the WD, a phase rotation to the one of the four antennas, the phase rotation corresponding to the indicated CSI-RS resource.

Phase error compensation for downlink systems with four correlated and uncalibrated antennas

Embodiments of a method in a base station configured to transmit and receive wireless signals to and from a user equipment, UE. A downlink channel response of a first UE antenna is determined, based on uplink signals received from the UE. First preceding weights are calculated based on the determined channel response of the first UE antenna. Orthogonal or quasi-orthogonal preceding weights are determined based on the first preceding weights. First and second downlink signal layers are transmitted using the first preceding weights and the orthogonal or quasi-orthogonal preceding weights.

Calculation of beamforming weights for reciprocity based beamforming without UE transmit antenna selection

A network node, wireless device and methods for co-phasing for beamforming using co-phasing matrices for wireless communications are provided. In one example, a network node for co-phasing in beamforming for transmissions is provided. The network node includes processing circuitry including a processor and a memory where the memory contains instructions executable by the processor to configure the network node to: obtain co-phasing information associated with a wireless device, generate at least two co-phasing matrices based on the co-phasing information, and apply the at least two co-phasing matrices to at least two resource structures.

Adaptive co-phasing for beamforming using co-phasing matrices for wireless communications

A method and system for performing link adaptation are disclosed. According to one aspect, a method in a wireless communication system for performing link adaptation is provided. The method includes, when a first measure of channel quality is higher than a first predetermined amount, using a first outer loop adjustment process directed to determining link adaptation for a first data transmission transmitted to a wireless device. The method also includes, when the first measure of channel quality is lower than a second predetermined amount, using a second outer loop adjustment process different from the first outer loop adjustment process directed to determining link adaptation for a second data transmission transmitted to the wireless device.

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Kanata, Canada

Jianguo Long