Telefonaktiebolaget Lm Ericsson (publ)

Umut Ugurlu

Icaro L J Da Silva

Rui Fan

Claes Tidestav

Pradeepa Ramachandra

Edgar Ramos

Qingyu Miao

Hai Feng Wang

Reza Moosavi

An access node transmits, in a downlink signal having a series of subframes, a beam-formed reference signal in subframes, where the beam-formed reference signals are transmitted in fewer than all of the subframes of the downlink signal. A first subset includes beam-formed reference signals corresponding to a first frequency or first localized range of frequencies, and a second subset includes beam-formed reference signals corresponding to a second frequency or second localized range of frequencies. The second frequency or second localized range of frequencies is spaced apart from and differing from the first frequency or first localized range of frequencies. A user equipment, UE, receives, in the downlink signal, the beam-formed reference signal in each of a plurality of subframes. The UE performs mobility management measurements using at least the first subset of the received beam-formed reference signals and performs RLM using the second subset of the received beam-formed reference signals.

Enhancements to mobility reference signals for radio link monitoring in a beam-based system

A user equipment, UE, performs measurements based on a plurality of RLM sources received in beam-formed downlink signals, where the measurements indicate a quality of a given cell or beam. The plurality of sources comprises two or more of: first reference signals (RSs), second RSs of a different type than the first RSs, and one or more physical channel quality indicators obtained from non-reference-signal data in the beam-formed downlink signals. For each of the plurality of sources used to perform measurements, the UE determines whether a measurement for the respective source indicates an out-of-sync event in response to the measurement being below a first threshold. The UE then performs an RLM action based on determined occurrences of out-of-sync events.

RLM and beam failure detection based on a mix of different reference signals

According to some embodiments, a method for use in a network node of transmitting reference signals in a wireless network using a plurality of beams comprises obtaining a node identifier for the network node. The node identifier is unique for neighboring network nodes within a particular coverage area of the wireless network. The method further comprises obtaining a group of reference signal sequences. The group comprises a subset of a pool of possible reference signal sequences for use in the wireless network. Each reference signal sequence is associated with a beam reference identifier. The method further comprises selecting a reference signal sequence from the obtained group: scrambling a reference signal transmission pattern using the obtained node identifier and the selected reference signal sequence with associated beam reference identifier; and transmitting the scrambled reference signal transmission pattern to a user equipment on one of the beams among the plurality of beams.

Minimizing network planning using reference signal grouping

An access node configures a user equipment, UE, to perform mobility management measurements using at least a first subset of beam-formed reference signals and to perform radio link monitoring, RLM, using at least some of the first subset of beam-formed reference signals used for the mobility management measurements. The access node transmits, in a first downlink signal having a series of subframes, a beam-formed reference signal in each of a plurality of subframes, where the beam-formed reference signals are transmitted in fewer than all of the subframes of the downlink signal. The UE receives, in the beam-formed downlink signal, the beam-formed reference signal in each of the plurality of subframes. The UE performs mobility management measurements using at least a first subset of the received beam-formed reference signals and performs RLM using at least some of the first subset of beam-formed reference signals used for the mobility management measurements.

Reuse of mobility reference signals to perform radio link monitoring in a beam-based system

There is provided a method for selectively enabling periodic transmission of reference signals in a wireless communication network. The method comprises obtaining (S) information of user activity in one or more beams, cells or sector, and performing (S) at least one of activating and deactivating, for at least one beam, cell or sector, periodic transmission of reference signals based on the obtained information.

Growing community of inventors

Cambridge, United Kingdom

Umut Ugurlu