Telefonaktiebolaget Lm Ericsson (publ)

Shaohua Li

Robert Baldemair

Daniel Chen Larsson

Mattias Frenne

Jinhua Liu

Sebastian Faxér

Yu Yang

Xinghua Song

Zhiheng Guo

Gustav Wikström

Imadur Rahman

Jianguo Long

Yongquan Qiang

Shiguang Guo

Sebastian FAXÉR

Kevin Luo

Chaocheng Tu

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

Embodiments of a method performed by a base station for adaptive Channel State Information (CSI) reporting configuration and/or Physical Resource Block (PRB) bundling and corresponding embodiments of a base station are disclosed. In some embodiments, a method performed by a base station comprises obtaining one or more parameters comprising one or more measurements of channel dispersiveness of a wireless channel between the base station and a User Equipment (UE), an uplink (UL) power-limited status of the UE, and/or an allocation bandwidth for the UE. The method further comprises selecting, based on the one or more parameters, a CSI report configuration for the UE and/or a PRB bundling configuration for the UE. The method further comprises transmitting, to the UE, information that indicates the selected CSI report configuration and/or information that indicates the selected PRB bundling configuration.

Adaptive CSI reporting and PRB bundling in AAS

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 some embodiments, a network node configured to communicate with a wireless device is provided. The network node includes processing circuitry configured to: configure a first measurement resource for channel measurements, configure a second measurement resource for interference measurements, cause transmission of a first signal with a first predefined power level in a transmission occasion of the first measurement resource, and cause transmission of a second signal with a second predefined power level in a transmission occasion of the second measurement resource where at least one of the first predefined power level and the second predefined power level is configured to at least in part mitigate channel quality indication, CQI, saturation.

Channel quality indication (CQI) saturation mitigation

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.

Growing community of inventors

Kanata, Canada

Shaohua Li