# US 11,122,571 B2 · Approaches for beam selection

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- Number: US 11,122,571 B2
- Document ID: US11122571B2
- Status: Granted
- Kind: B2
- Application number: 16/314,515
- Filed: 2018-11-30
- Published: 2021-07-29
- Granted: 2021-09-14
- Earliest claimed: 2018-11-30
- Assignees: Telefonaktiebolaget LM Ericsson (publ)
- Applicants: Telefonaktiebolaget LM Ericsson (publ)
- Inventors: Joao Vieira; Dzevdan Kapetanovic
- Web page: https://patentgrep.com/patent/US11122571B2

## CPC

- H04W 72/046: {the resource being in the space domain, e.g. beams}
- H04B 7/0408: using two or more beams, i.e. beam diversity
- H04B 7/0617: {for beam forming}
- H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection}
- H04B 7/06952: {Selecting one or more beams from a plurality of beams, e.g. beam training, management or sweeping}
- H04B 7/088: {using beam selection}
- H04B 17/382: for resource allocation, admission control or handover
- H04B 17/3912: {Simulation models, e.g. distribution of spectral power density or received signal strength indicator [RSSI] for a given geographic region}
- H04W 16/28: using beam steering
- H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports}
- H04W 84/02: Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W 88/02: Terminal devices
- H04W 88/08: Access point devices
- H04W 92/10: between terminal device and access point, i.e. wireless air interface
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION

## Abstract

A method is disclosed for a system comprising a transmitter apparatus and a receiver apparatus. The transmitter apparatus is configured to transmit signals to the receiver apparatus using an available transmission beam. The receiver apparatus is configured to receive the signals using an available reception beam. The method comprises the transmitter apparatus determining a collection of linear combinations of transmission beams and a collection of linear combinations of reception beams, providing an indication of the collection of linear combinations of reception beams to the receiver apparatus and transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams. The method also comprises the receiver apparatus acquiring the indication of the collection of linear combinations of reception beams from the transmitter apparatus, receiving each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams using each of the linear combinations of reception beams of the collection of linear combinations of reception beams, and performing beam selection measurements on the received linear combinations of transmission beams for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams. Methods for each of the transmitter apparatus and the receiver apparatus are also disclosed, as well as corresponding apparatuses, network node, wireless communication device, system and computer program product.

## Claims

### Claim 1

A method for a transmitter apparatus configured to transmit signals to a receiver apparatus using a transmission beam selected from a plurality of available transmission beams, wherein the receiver apparatus is configured to receive the signals using a reception beam selected from a plurality of available reception beams, and wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, the method comprising:
determining a collection of linear combinations of transmission beams of the set of the available transmission beams;
determining a collection of linear combinations of reception beams of the set of available reception beams;
providing an indication of the collection of linear combinations of reception beams to the receiver apparatus; and
transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams for beam selection measurements by the receiver apparatus.

### Claim 2 (depends on 1)

The method of claim 1, wherein the collection of linear combinations of transmission beams and the collection of linear combinations of reception beams are determined jointly.

### Claim 3 (depends on 1)

The method of claim 1, wherein:
a cardinality of the collection of linear combinations of transmission beams is lower than a cardinality of the set of the available transmission beams; and/or
a cardinality of the collection of linear combinations of reception beams is lower than a cardinality of the set of the available reception beams.

### Claim 4 (depends on 3)

The method of claim 3, wherein the determination of the collection of linear combinations of transmission beams and the collection of linear combinations of reception beam comprises determining the cardinality of the collection of linear combinations of transmission beams and/or the cardinality of the collection of linear combinations of reception beam based on one or more of:
a sparsity of a channel between the transmitter apparatus and the receiver apparatus; and
properties of a compression matrix representing the collection of linear combinations of transmission beams and the collection of linear combinations of reception beams.

### Claim 5 (depends on 1)

The method of claim 1, further comprising:
receiving a transmission beam selection measurement report from the receiver apparatus; and
selecting the transmission beam from the plurality of available transmission beams in accordance with the received transmission beam selection measurement report.

### Claim 6 (depends on 1)

The method of claim 1, wherein at least one of the linear combinations of transmission beams of the collection of linear combinations of transmission beams is a linear combination of at least two of the transmission beams of the set of the available transmission beams, and/or wherein at least one of the linear combinations of reception beams of the collection of the collection of linear combinations of reception beams is a linear combination of at least two of the reception beams of the set of the available reception beams.

### Claim 7 (depends on 1)

The method of claim 1, wherein each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams is a unique linear combination of all of the transmission beams of the set of the available transmission beams, and/or wherein each of the linear combinations of reception beams of the collection of the collection of linear combinations of reception beams is a unique linear combination of all of the reception beams of the set of the available reception beams.

### Claim 8 (depends on 1)

The method of claim 1, wherein the collection of linear combinations of transmission beams is defined by a Grassmannian coding matrix, and/or wherein the collection of linear combinations of reception beams is defined by a Grassmannian coding matrix.

### Claim 9 (depends on 1)

The method of claim 1, wherein the collection of linear combinations of transmission beams, representable by a matrix BTX, and the collection of linear combinations of reception beams, representable by a matrix BRX, are determined such that AHA is a substantially block diagonal matrix, wherein A=BTX⊗BRX where ⊗ represents a Kronecker product.

### Claim 10 (depends on 1)

The method of claim 1, wherein the set of the available transmission beams consists of a minimum number of transmission beams spanning the plurality of available transmission beams, and/or wherein the set of the available reception beams consists of a minimum number of reception beams spanning the plurality of available reception beams.

### Claim 11 (depends on 1)

The method of claim 1, wherein the set of the available transmission beams and/or the set of the available reception beams comprises discrete Fourier transform, DFT, beams, wherein a beam direction of any DFT beam corresponds to a harmonic frequency.

### Claim 12 (depends on 1)

The method of claim 1, wherein transmitting comprises one or more of:
transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams in a respective transmission time resource, at least some of the respective time resources being different; and
transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams in a respective transmission frequency resource, at least some of the respective frequency resources being different.

### Claim 13 (depends on 1)

The method of claim 1, wherein the method is applied during a training phase for beam selection.

### Claim 14

A method for a receiver apparatus configured to receive signals from a transmitter apparatus via a transmission beam selected from a plurality of available transmission beams and using a reception beam selected from a plurality of available reception beams, wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, the method comprising:
acquiring, from the transmitter apparatus, an indication of a collection of linear combinations of reception beams of the set of the available reception beams;
receiving, using each of the linear combinations of reception beams of the collection of linear combinations of reception beams, a number of measurement signals for beam selection measurements from the transmitter apparatus, wherein the number of measurement signals correspond to a collection of linear combinations of transmission beams of the set of available transmission beams; and
performing beam selection measurements on the number of measurement signals for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams.

### Claim 15 (depends on 14)

The method of claim 14, further comprising:
transmitting a transmission beam selection measurement report to the transmitter apparatus for selection of the transmission beam from the plurality of available transmission beams.

### Claim 16 (depends on 14)

The method of claim 14, wherein performing beam selection measurements comprises determining a quality metric for each combination of a transmission beam of the set of available transmission beams and a reception beam of the set of available reception beams based on the beam selection measurements.

### Claim 17 (depends on 14)

The method of claim 14, wherein performing beam selection measurements comprises subjecting the number of received measurement signals to matched filtering based on the collection of linear combinations of transmission beams and the collection of linear combinations of reception beam.

### Claim 18

A method for a system comprising a transmitter apparatus and a receiver apparatus, wherein the transmitter apparatus is configured to transmit signals to the receiver apparatus using a transmission beam selected from a plurality of available transmission beams, wherein the receiver apparatus is configured to receive the signals using a reception beam selected from a plurality of available reception beams, and wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, the method comprising:
determining, by the transmitter apparatus, a collection of linear combinations of transmission beams of the set of the available transmission beams;
determining, by the transmitter apparatus, a collection of linear combinations of reception beams of the set of available reception beams;
providing, by the transmitter apparatus to the receiver apparatus, an indication of the collection of linear combinations of reception beams;
acquiring, by the receiver apparatus from the transmitter apparatus, the indication of the collection of linear combinations of reception beams;
transmitting, by the transmitter apparatus, each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams;
receiving, by the receiver apparatus, each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams using each of the linear combinations of reception beams of the collection of linear combinations of reception beams; and
performing, by the receiver apparatus, beam selection measurements on the received linear combinations of transmission beams for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams.

### Claim 19

A computer program product comprising a non-transitory computer readable medium, having thereon a computer program comprising program instructions, the computer program being loadable into a data processing unit and configured to cause execution of a method when the computer program is run by the data processing unit, wherein the method is for a transmitter apparatus configured to transmit signals to a receiver apparatus using a transmission beam selected from a plurality of available transmission beams, wherein the receiver apparatus is configured to receive the signals using a reception beam selected from a plurality of available reception beams, and wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, and wherein the method comprises:
determining a collection of linear combinations of transmission beams of the set of the available transmission beams;
determining a collection of linear combinations of reception beams of the set of available reception beams;
providing an indication of the collection of linear combinations of reception beams to the receiver apparatus; and
transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams for beam selection measurements by the receiver apparatus.

### Claim 20

A transmitter apparatus configured to transmit signals to a receiver apparatus using a transmission beam selected from a plurality of available transmission beams, wherein the receiver apparatus is configured to receive the signals using a reception beam selected from a plurality of available reception beams, and wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, the apparatus comprising controlling circuitry configured to cause:
determination of a collection of linear combinations of transmission beams of the set of the available transmission beams;
determination of a collection of linear combinations of reception beams of the set of available reception beams;
provision of an indication of the collection of linear combinations of reception beams to the receiver apparatus; and
transmission of each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams for beam selection measurements by the receiver apparatus.

### Claim 21 (depends on 20)

The transmitter apparatus of claim 20, wherein the controlling circuitry is configured to cause joint determination of the collection of linear combinations of transmission beams and the collection of linear combinations of reception beams.

### Claim 22 (depends on 20)

The transmitter apparatus of claim 20, wherein:
a cardinality of the collection of linear combinations of transmission beams is lower than a cardinality of the set of the available transmission beams; and/or
a cardinality of the collection of linear combinations of reception beams is lower than a cardinality of the set of the available reception beams.

### Claim 23 (depends on 22)

The transmitter apparatus of claim 22, wherein the controlling circuitry is configured to cause the determination of the collection of linear combinations of transmission beams and the collection of linear combinations of reception beam by causing determination of the cardinality of the collection of linear combinations of transmission beams and/or the cardinality of the collection of linear combinations of reception beam based on one or more of:
a sparsity of a channel between the transmitter apparatus and the receiver apparatus; and
properties of a compression matrix representing the collection of linear combinations of transmission beams and the collection of linear combinations of reception beams.

### Claim 24 (depends on 20)

The transmitter apparatus of claim 20, wherein the controlling circuitry is further configured to cause:
reception of a transmission beam selection measurement report from the receiver apparatus; and
selection of the transmission beam from the plurality of available transmission beams in accordance with the received transmission beam selection measurement report.

### Claim 25 (depends on 20)

The transmitter apparatus of claim 20, wherein the controlling circuitry is configured to cause the transmission by causing one or more of:
transmission of each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams in a respective transmission time resource, at least some of the respective time resources being different; and
transmission of each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams in a respective transmission frequency resource, at least some of the respective frequency resources being different.

### Claim 26 (depends on 20)

The transmitter apparatus of claim 20, wherein the controlling circuitry is configured to enable the determination of the collections, the provision of the indication, and the transmission of the linear combinations of transmission beams for application during a training phase for beam selection.

### Claim 27

A receiver apparatus configured to receive signals from a transmitter apparatus via a transmission beam selected from a plurality of available transmission beams and using a reception beam selected from a plurality of available reception beams, wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, the apparatus comprising controlling circuitry configured to cause:
acquisition, from the transmitter apparatus, of an indication of a collection of linear combinations of reception beams of the set of the available reception beams;
reception, using each of the linear combinations of reception beams of the collection of linear combinations of reception beams, of a number of measurement signals for beam selection measurements from the transmitter apparatus, wherein the number of measurement signals correspond to a collection of linear combinations of transmission beams of the set of available transmission beams; and
performance of beam selection measurements on the number of measurement signals for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams.

### Claim 28 (depends on 27)

The receiver apparatus of claim 27, wherein the controlling circuitry is further configured to cause:
transmission of a transmission beam selection measurement report to the transmitter apparatus for selection of the transmission beam from the plurality of available transmission beams.

### Claim 29 (depends on 27)

The receiver apparatus of claim 27, wherein the controlling circuitry is configured to cause performance of beam selection measurements by causing determination of a quality metric for each combination of a transmission beam of the set of available transmission beams and a reception beam of the set of available reception beams based on the beam selection measurements.

### Claim 30 (depends on 27)

The receiver apparatus of claim 27, wherein the controlling circuitry is configured to cause performance of beam selection measurements by causing subjection of the number of received measurement signals to matched filtering based on the collection of linear combinations of transmission beams and the collection of linear combinations of reception beam.

### Claim 31 (depends on 20)

A network node comprising the transmitter apparatus of claim 20.

### Claim 32 (depends on 20)

A wireless communication device comprising the transmitter apparatus of claim 20.

### Claim 33

A system comprising a transmitter apparatus and a receiver apparatus, wherein the transmitter apparatus is configured to transmit signals to the receiver apparatus using a transmission beam selected from a plurality of available transmission beams, wherein the receiver apparatus is configured to receive the signals using a reception beam selected from a plurality of available reception beams, and wherein a set of the available transmission beams and a set of the available reception beams are for beam selection measurements by the receiver apparatus, wherein:
the transmitter apparatus is configured to:
determine a collection of linear combinations of transmission beams of the set of the available transmission beams;
determine a collection of linear combinations of reception beams of the set of available reception beams;
provide, to the receiver apparatus, an indication of the collection of linear combinations of reception beams; and
transmit each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams; and
the receiver apparatus is configured to:
acquire, from the transmitter apparatus, the indication of the collection of linear combinations of reception beams;
receive each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams using each of the linear combinations of reception beams of the collection of linear combinations of reception beams; and
perform beam selection measurements on the received linear combinations of transmission beams for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams.

### Claim 34 (depends on 27)

A network node comprising the receiver apparatus of claim 27.

### Claim 35 (depends on 27)

A wireless communication device comprising the receiver apparatus of claim 27.