Telefonaktiebolaget Lm Ericsson (publ)

Guoqiang Lu

Edward Mah

Xixian Chen

Fredrik Huss

Ping Yu

Qingchao Liu

Eric W Parsons

Oskar Mauritz

Lisa Boström

Karl D Mann

Iris Bujold

Henrik Back

Richard Liu

Jamie Beuerman

Damitha Ranaweera

Hong Ren

Shiguang Guo

James Jianfeng Weng

Ying Shao

Hua Xu

Jianguo Long

Patrick Lie Chin Cheong

Ahmed Nouah

Guoqiang Xue

Peter Hazy

Dimple Thomas

Michel Chauvin

Michael Roger

Hong Yu

Weihong Liu

Daryl Smith

Lisa BOSTRÖM

Embodiments of a method for measurement of electromagnetic field strength at a point of interest in a coverage area of a 2-dimensional (2D) active antenna system (AAS). The 2D AAS transmits with a load factor of 100 percent. The 2D AAS sweeps a predefined range of azimuth and elevation angles, and azimuth and elevation directions which yield highest EMF at the point of interest are determined. First beamforming weights are determined based on the azimuth and elevation directions and the 2D AAS caused to apply the first beamforming weights. The 2D AAS sweeps a co-phasing angle from 0 to 360 degrees, and a co-phasing angle which yields highest EMF is determined. Second beamforming weights are determined based on azimuth and elevation directions and the co-phasing angle, and the 2D AAS caused to apply the second beamforming weights. The EMF strength at the point of interest is measured.

Method of measuring AAS EMF

Systems and methods for improved Physical Downlink Control Channel (PDCCH) Link Adaptation (LA) in carrier aggregation are disclosed. A method of operation of a radio access node includes transmitting multiple control messages to the wireless device via PDCCHs associated with corresponding serving cells of the wireless device, informing the wireless device of data transmissions to be transmitted to the wireless device via Physical Downlink Shared Channels of the corresponding serving cells and concurrently operating multiple Physical Uplink Control Channel (PUCCH) receivers on one serving cell during a Transmit Time Interval during which feedback from the wireless device indicative of reception of the data transmissions is expected, where each PUCCH receiver is capable of receiving a different format PUCCH message if necessary. The method also includes updating an outer loop LA parameter for each of the PDCCHs based on the determined PDCCH transmission status.

PDCCH link adaptation in carrier aggregation

Systems and methods for Multiple-Input and Multiple-Output (MIMO) rank reduction to improve downlink throughput are disclosed. A method of operation of a radio access node includes determining that an imbalance between parallel channels of a spatial multiplexing downlink transmission to a wireless device is greater than an imbalance threshold and/or that a Negative Acknowledgement (NACK) rate over time for the parallel channels of a spatial multiplexing downlink transmission reported by the wireless device is greater than a NACK rate threshold. The method also includes, in response to determining that the imbalance between the parallel channels is greater than the imbalance threshold and/or that the NACK rate is greater than the NACK rate threshold, performing a fast rank reduction for a next downlink transmission whereby a rank is reduced from a rank indicator reported by the wireless device to some lower rank. Reducing the rank may improve downlink throughput.

MIMO rank reduction to improve downlink throughput

Systems and methods for Secondary Cell (sCell) selection for wireless devices operating according to a carrier aggregation scheme in a cellular communications network are disclosed. In one embodiment, a network node in the cellular communications network obtains geographic signatures for a number of candidate sCells. The geographic signatures include a geographic signature for each candidate sCell that approximates a coverage area of the candidate sCell. The network node obtains position information for a wireless device and then selects one or more sCells for the wireless device from the candidate sCells based on the geographic signatures for the candidate sCells and the position information for the wireless device. The network node then configures the selected sCell(s) for use by the wireless device according to a carrier aggregation scheme. Using this process, sCell selection is performed, in some examples, without measurement gaps and without disabling an s-Measure parameter.

Secondary cell selection based on geographic signatures

Systems and methods for Secondary Cell (sCell) selection for wireless devices operating according to a carrier aggregation scheme in a cellular communications network are disclosed. In one embodiment, a network node obtains a list of potential sCells for a wireless device. The network node blindly selects an sCell for the wireless device from the list of potential sCells. The network node then configures the wireless device with the selected sCell. Blindly selecting the sCell for the wireless device makes it possible to avoid the use of measurement gaps and reduce throughput loss, according to some embodiments.

Carrier aggregation sCell selection for LTE-A

In one embodiment, a method of operating a radio access node is provided. The method comprises determining whether support from a secondary cell is required for a wireless device to communicate with the radio access node, and, in response to determining that support from the secondary cell is required, calculating a modified channel condition outer-loop value for the secondary cell; and using the modified channel condition outer-loop value in an initial activation decision step for the secondary cell. The initial activation decision step may comprise activating the secondary cell in response to determining that the sum of a device reported channel condition value and the modified channel condition outer-loop value is above an activation threshold. Corresponding devices, computer programs and radio access nodes adapted to carry out the methods provided are also disclosed.

Secondary cell activation/deactivation in carrier aggregation

Systems and methods for subframe-based link adaptation for a radio signal in a cellular communications network are disclosed. In one embodiment, a base station obtains a hybrid automatic repeat request acknowledgement for data transmitted between the base station and a mobile terminal in a radio signal of the base station. The base station then updates a parameter (e.g., SINR offset) used to control a Modulation and Coding Scheme (MCS) for transmission of data between the base station and the mobile terminal in the radio signal for one or more subframes in a frame structure of the radio signal based on the hybrid automatic repeat request acknowledgement. The one or more subframes are a subset of all of the subframes in the frame structure of the radio signal.

Multiple outer loop link adaptation

A method and apparatus for frequency offset estimation exploits the differences in reference symbol timing for different channels to resolve ambiguities in the frequency offset estimation. Based on the initial frequency offset estimates, a hypothesis table is constructed providing hypothesized frequency offsets for each channel for a plurality of possible offset regions. An error metric for each offset region is calculated based on the difference of the hypothesized frequency offsets. The set of hypothesized frequency offsets that minimize the error metric is selected as the final frequency offset estimates.

Estimation of frequency offset between a base station and mobile terminal

A method and base station for adjusting outer-loop adjustment values used for link adaptation in a wireless communication network is provided. A modulation of a user equipment is determined and a success or failure of a Transport Block (TB) based on a TB feedback message is determined. Based on the TB feedback, one of an acknowledgement counter and a non-acknowledgement counter is incremented corresponding to the determined modulation. An upward step size for the determined modulation is updated based on the respective acknowledgement counter and the non-acknowledgement counter to affect link adaption.

Outer-loop adjustment for wireless communication link adaptation

A method and base station for outerloop adjustment for link adaptation of a physical downlink control channel, PDCCH, in a communication network to determine a control channel element, CCE, aggregation level of a downlink assignment downlink control information, DCI, and a CCE aggregation level of an uplink grant DCI is provided. A downlink data packet feedback corresponding to the downlink assignment is received. A status of the downlink data packet feedback is determined. An uplink data packet corresponding to the uplink grant is received and a status thereof is determined. An outerloop downlink adjustment and outerloop uplink adjustment are updated based on at least one of the status of the downlink data packet feedback corresponding to the downlink assignment and status of the uplink data packet corresponding to the uplink grant. An outerloop uplink adjustment is determined as a sum of the outerloop downlink adjustment and an offset adjustment.

Outer-loop control in wireless communication link adaptation

Growing community of inventors

Kanata, Canada

Guoqiang Lu