# US 2013/0156010 A1 · Beam Information Exchange between Base Stations

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- Number: US 2013/0156010 A1
- Document ID: US20130156010A1
- Status: Published application
- Kind: A1
- Application number: 13/716,132
- Filed: 2012-12-15
- Published: 2013-06-20
- Earliest claimed: 2011-12-19
- Assignees: Ofinno Technologies, LLC
- Inventors: Esmael Hejazi Dinan
- Web page: https://patentgrep.com/patent/US20130156010A1

## CPC

- H04W 36/0058: {Transmission of hand-off measurement information, e.g. measurement reports}
- H04B 7/0417: Feedback systems
- H04B 7/043: {using best eigenmode, e.g. beam forming or beam steering}
- H04B 7/0456: Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
- H04B 7/046: {taking physical layer constraints into account}
- H04B 7/0473: {taking constraints in layer or codeword to antenna mapping into account}
- H04B 7/0478: {Special codebook structures directed to feedback optimisation}
- H04B 7/0481: {using subset selection of codebooks}
- H04B 7/0617: {for beam forming}
- H04B 7/0626: {Channel coefficients, e.g. channel state information [CSI]}
- H04B 7/063: {Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection}
- H04B 7/0634: {Antenna weights or vector/matrix coefficients}
- H04B 7/0639: {Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection}
- H04J 11/0056: {Inter-base station aspects}
- H04L 5/0023: {Time-frequency-space}
- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 5/0073: {Allocation arrangements that take into account other cell interferences}
- H04L 25/03955: {in combination with downlink estimations, e.g. downlink path losses}
- H04L 27/2646: {using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length}
- H04W 24/02: Arrangements for optimising operational condition
- H04W 28/0236: {radio quality, e.g. interference, losses or delay}
- H04W 36/0064: {of control information between different access points}
- H04W 36/0072: {of resource information of target access point}
- H04W 36/0094: {Definition of hand-off measurement parameters}
- H04W 36/085: {involving beams of access points}
- H04W 36/30: by measured or perceived connection quality data
- H04W 72/044: based on the type of the allocated resource
- H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA
- H04W 72/046: {the resource being in the space domain, e.g. beams}
- H04W 72/20: Control channels or signalling for resource management
- H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal
- H04W 72/27: between access points
- H04W 72/541: using the level of interference
- H04W 74/002: {Transmission of channel access control information}
- H04W 88/08: Access point devices
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04B: TRANSMISSION
- H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A first base station receives an application protocol message from a second base station. The application protocol message comprises an identifier of the second base station and a beamforming codebook. The beamforming codebook comprises a plurality of beamforming codewords. Each of the plurality of beamforming codewords is identifiable by an index. The first base station transmits signals to wireless devices using a subset of the plurality of beamforming codewords.

## Claims

### Claim 1

A method comprising:
a) transmitting, by a first base station, a first message to initiate an association between said first base station and a second base station, said first message comprising a first initiation tag;
b) receiving, by said first base station, a second message from said second base station, said second message comprising:
i) a second verification tag, said second verification tag equal to said first initiation tag;
ii) a second initiation tag; and
iii) a first state parameter comprising:
(1) at least one parameter related to operational information of said association; and
(2) a message authentication code generated as a function of a private key;
c) transmitting, by said first base station, at least one third message to said second base station, said at least one third message comprising:
i) a first verification tag, said first verification tag equal to said second initiation tag; and
ii) a parameter comprising said first state parameter; and
d) receiving, by said first base station, at least one fourth message from said second base station, said at least one fourth message comprising:
i) an acknowledgement for the receipt of said parameter; and
ii) a first application protocol message, comprising:
(1) an identifier of said second base station;
(2) at least one mobility management entity group identifier; and
(3) a second beamforming codebook comprising a second plurality of beamforming codewords, each of said second plurality of beamforming codewords being identifiable by an index, said index presented by a number of bits, said number of bits being:
(a) greater than or equal to log2(N), N being the number of said second plurality of beamforming codewords; and
(b) less than the number of bits in a corresponding beamforming codeword;
e) receiving, by said first base station from said second base station, at least one second application protocol message comprising at least one index in said plurality of indexes, said at least one index identifying a subset of said second plurality of beamforming codewords; and
f) transmitting, by said first base station, signals to a plurality of wireless devices employing a first plurality of beamforming codewords from a first beamforming codebook, said first plurality of codewords being selected, at least in part, employing said subset of said second plurality of beamforming codewords.

### Claim 2 (depends on 1)

The method of claim 1, wherein said first initiation tag value is selected in said first base station employing a pseudo-random process.

### Claim 3 (depends on 1)

The method of claim 1, wherein said first base station employs said plurality of indexes in communications with said second base station, each of said plurality of indexes referring to a locally unique beamforming codeword.

### Claim 4 (depends on 1)

The method of claim 1, wherein said first application protocol message further comprises a cell ID for each cell in said second base station.

### Claim 5 (depends on 1)

The method of claim 1, wherein said first application protocol message further comprises the frequency of at least one downlink carrier and at least one uplink carrier of said second base station.

### Claim 6

A method comprising:
a) receiving, by a first base station, a first application protocol message from a second base station, said first application protocol message comprising:
i) an identifier of said second base station; and
ii) a second beamforming codebook comprising a second plurality of beamforming codewords, each of said second plurality of beamforming codewords being identifiable by an index, said index presented by a number of bits, said number of bits being:
(1) greater than or equal to log2(N), N being the number of said second plurality of beamforming codewords; and
(2) less than the number of bits in a corresponding beamforming codeword;
b) receiving, by said first base station from said second base station, at least one second application protocol message comprising at least one index in said plurality of indexes, said at least one index identifying a subset of said second plurality of beamforming codewords; and
c) transmitting, by said first base station, signals to a plurality of wireless devices employing a first plurality of beamforming codewords from a first beamforming codebook, said first plurality of codewords being selected, at least in part, employing said subset of said second plurality of beamforming codewords.

### Claim 7 (depends on 6)

The method of claim 6, further comprising configuring said first plurality of beamforming codewords to reduce inter-cell interference generated, at least in part, by said second base station.

### Claim 8 (depends on 7)

The method of claim 7, further comprising said first base station computing inter-cell interference from said second base station employing information received from at least one wireless device.

### Claim 9 (depends on 6)

The method of claim 6, further comprising configuring said first plurality of beamforming codewords to reduce inter-cell interference generated, at least in part, by said first base station.

### Claim 10 (depends on 9)

The method of claim 9, further comprising said first base station computing intercell interference affecting said second base station employing information received from at least one wireless device.

### Claim 11 (depends on 6)

The method of claim 6, further comprising configuring said first beamforming codebook or said second beamforming codebook for a number of transmit antennas, said first beamforming codebook or said second beamforming codebook comprising a set of codewords, each codeword having a number of rows or columns equal to said number of transmit antennas.

### Claim 12 (depends on 11)

The method of claim 11, further comprising constructing codewords for a subset of transmit antennas employing a subset of rows or columns of said codewords.

### Claim 13 (depends on 6)

The method of claim 6, wherein said first beamforming codebook or said second beamforming codebook is defined for a number of layers and comprises a set of original codewords, each original codeword having a number columns equal to said maximum number of layers.

### Claim 14 (depends on 13)

The method of claim 13, further comprising constructing codewords for a subset of layers by employing a subset of columns or rows of said original codewords.

### Claim 15 (depends on 6)

The method of claim 6, further comprising said second base station transmitting said second beamforming codebook to a plurality of base stations.

### Claim 16 (depends on 15)

The method of claim 15, further comprising said plurality of base stations selecting respective first plurality of beamforming codewords based on information received from said second base station in said first application protocol message.

### Claim 17

A first base station comprising:
a) one or more communication interfaces;
b) one or more processors; and
c) memory storing instructions that, when executed, cause said first base station to:
i) receive a first application protocol message from a second base station, said first application protocol message comprising:
(1) an identifier of said second base station; and
(2) a second beamforming codebook comprising a second plurality of beamforming codewords, each of said second plurality of beamforming codewords being identifiable by an index, said index presented by a number of bits, said number of bits being:
(a) greater than or equal to log2(N), N being the number of said second plurality of beamforming codewords; and
(b) less than the number of bits in a corresponding beamforming codeword;
ii) receive from said second base station, at least one second application protocol message comprising at least one index in said plurality of indexes, said at least one index identifying a subset of said second plurality of beamforming codewords; and
iii) transmit signals to a plurality of wireless devices employing a first plurality of beamforming codewords from a first beamforming codebook, said first plurality of codewords being selected, at least in part, employing said subset of said second plurality of beamforming codewords.

### Claim 18 (depends on 17)

The first base station of claim 17, wherein said first plurality of beamforming codewords are configured to reduce inter-cell interference generated from said second base station.

### Claim 19 (depends on 18)

The first base station of claim 18, wherein said instruction, when executed, further cause said first base station to employ information received from at least one wireless device to compute the inter-cell interference from said second base station.

### Claim 20 (depends on 17)

The first base station of claim 17, wherein said first plurality of beamforming codewords are configured to reduce inter-cell interference generated from said first base station.