WO2015165502A1

WO2015165502A1 - Base station antenna system with orientation sensor

Info

Publication number: WO2015165502A1
Application number: PCT/EP2014/058679
Authority: WO
Inventors: Karel Sotek; Songhai Wang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2014-04-29
Filing date: 2014-04-29
Publication date: 2015-11-05
Also published as: CN106233529B; CN106233529A; EP3138153A1

Abstract

The present invention relates to a base station antenna system (100) and a base station (200). The antenna system comprises at least one antenna element (101) and at least one orientation sensor (102) configured to output orientation data (103). The antenna system (100) comprises a control unit (102) that may be configured to calculate an elevation (104) and an azimuth (105) of the antenna element (101) based on the orientation data (103) and to provide the calculated values via an antenna interface to the base station (200), or is configured to provide raw sensor data to the base station (200) via the antenna interface. The base station (200) has a base band unit (202) configured to receive the calculated elevation (104) and azimuth (105) of one or more base station antenna system (100), or configured to receive the raw sensor data and to calculate the elevation value and azimuth value of the antenna element (101) of the at least one base station antenna system (100).

Description

BASE STATION ANTENNA SYSTEM WITH ORIENTATION SENSOR

TECHNICAL FIELD

The present invention relates to a base station antenna system with an orientation sensor. The present invention relates further to a base station and a communication system, respectively, including the base station antenna system. Finally, the present invention relates to a method for controlling a beam direction of an antenna element of the base station antenna system.

BACKGROUND

On the one hand side, broad acceptance and extensive usage of mobile broadband services puts enormous cost pressure on both setup and operation of base stations in a mobile cellular network. On the other hand side, for achieving homogenous radio network coverage, it is very important during the setup and operation of a base station (for example a BTS (Base Transceiver Station) site), to precisely set and maintain a beam direction of an antenna system. The beam direction is typically expressed by an azimuth and an elevation value, and is a key installation parameter, specifically for sectorized base station antennas in cellular networks.

The elevation (also called downtilt) of an antenna system is typically set to direct the antenna beam towards a cell capacity area. Thereby, also the so called overshoot (i.e. the overlap of neighbouring network cells) can be reduced. A proper elevation value depends on antenna height over ground, a cell radius and/or a terrain profile, and on the level of interfering into neighbouring network cells.

Typically a three-sector antenna setup is used for cellular networks. In this setup a base station comprises three antennas, wherein the azimuth values of the three antennas have an equal difference of 120° to one another. That means, a first antenna usually has an azimuth of 0° (e.g. heading north), a second antenna has an azimuth of 120°, and a third antenna has an azimuth of 240°. In a uniform network design, all neighbouring base stations share precisely the same values of the azimuth for their respective antenna systems.

Conventionally, the azimuth and elevation values of antennas are typically set and adjusted by mechanically positioning the antennas. Thereby, a compass and an angle against the optical horizon, respectively, are usually used. A disadvantage of the mechanical positioning is that any new adjustment of the azimuth and elevation of an antenna system, respectively, requires a new access to the antennas. Another disadvantage is that the mechanical positioning of the azimuth and elevation values is often erroneous. However, any erroneous setting of these values, or any erroneous adjustment of the azimuth and elevation, will inevitably degrade the network performance. Furthermore, if the azimuth and elevation values are mechanically set, a manual input into a system database is required, which is rather cost intensive and prone to errors.

SUMMARY

In view of the above-mentioned disadvantages and problems, the present invention aims to improve the state of the art. In particular, the object of the present invention is to provide a base station antenna system, a base station, and a communication system, respectively, which allow controlling and optimizing azimuth and elevation values of antenna systems. The present invention also intends to enable easy and precise adjustments of the azimuth and elevation values. The present invention also aims for an economical solution.

The above-mentioned object of the present invention is achieved by the solution provided in the enclosed independent claims. Advantageous implementations of the present invention are further defined in the respective dependent claims. In particular, a core idea of the present invention is to provide a base station antenna system with an orientation sensor, and thereby to firstly enable a precise determination of the azimuth and elevation of the antenna elements of the antenna system, and to secondly enable an automatic configuration of the azimuth and elevation value of the antenna system or at least of a beam direction of the antenna system. A first aspect of the present invention provides a base station antenna system comprising an antenna element, and an antenna control unit comprising an orientation sensor, the orientation sensor being configured to determine orientation data indicating a current orientation of the antenna element.

The orientation sensor may be embedded into or may be integrated with the antenna system. The orientation sensor may determine the orientation data, for example, current XYZ coordinates of the antenna element. Based on the orientation data, the azimuth and elevation of the antenna system can be easily calculated, and thus can be precisely determined. Further, the determined values can be automatically controlled and adjusted. Thus, mechanical positioning of the antenna system can be avoided.

In a first implementation form of the base station antenna system according to the first aspect, the antenna control unit and the antenna element are arranged in an antenna radome (i.e. in on and the same antenna radome).

Thereby, the antenna element and the orientation sensor are integrated with another, and are both well protected. The orientation sensor is preferably calibrated or positioned such in the radome, that the azimuth and elevation of the antenna element can be determined precisely.

In a second implementation form of the base station antenna system according to the first aspect as such or according to the first implementation form of the first aspect, the orientation sensor is configured to measure a deviation of its orientation from the magnetic north pole in a horizontal plane and a deviation from the gravity center in a vertical plane, and to determine the orientation data based on the measured deviations.

That means, the orientation sensor preferably senses the magnetic and gravitation fields, in order to generate and output the orientation data. Thereby, the orientation sensor can provide precise orientation data, which can be used to calculate azimuth and elevation. Magnetic orientation sensors are furthermore low-cost and very compact solutions. In a third implementation form of the base station antenna system according to the first aspect as such or according to any implementation forms of the first aspect, the antenna control unit is configured to calculate an elevation and an azimuth of the antenna element based on the orientation data and to provide the calculated azimuth and elevation via an antenna interface.

Thus, the antenna system itself is able to determine its azimuth and elevation. This may take load off the base station. The antenna control unit (e.g. an antenna controller of the antenna control unit) may, for instance, read the XYZ values provided by the orientation sensor, and may calculate from the XYZ values both the azimuth and elevation value. The calculated azimuth and elevation values can be output from the antenna system to a base station and/or may be used for antenna element adjustment, operation and maintenance purposes and for optimization. Also it is possible that the orientation sensor itself already provides elevation and azimuth values.

In a fourth implementation form of the base station antenna system according to the first aspect as such or according to any implementation forms of the first aspect, the orientation sensor is configured to provide raw sensor data as the orientation data, and the antenna control unit is configured to provide the raw sensor data via an antenna interface. Of course in a further implementation form, it also possible, that the antenna system outputs both raw sensor data and calculated elevation and azimuth.

In this case the calculation of the azimuth and elevation may be carried out outside the antenna system using the raw sensor data, for instance, in a control module of a base station that includes the antenna system. The antenna system needs in this case only the orientation sensor providing the raw sensor data, but not necessarily the ability to process the orientation data. Thus, the antenna system can be constructed simpler and cheaper. In a fifth implementation form of the base station antenna system according to the first aspect as such or according to any implementation forms of the first aspect, the antenna control unit comprises a memory, in which an offset information is stored, the offset information indicating a deviation between a sensing direction of the orientation sensor and a beam orientation (or beam direction) of the antenna element, wherein the antenna control unit is configured to output the stored offset information via an antenna interface or to calculate an elevation and an azimuth of the antenna element based on the orientation data and the stored offset information and to output the calculated elevation and azimuth via the antenna interface.

The offset information may be used to compensate tolerances that occur during antenna manufacturing. Thus, the azimuth and elevation values can be calculated more precisely. It is also possible to use the offset information for intentionally offsetting the beam direction of the antenna element. For example, a fixed downtilt value can be set on purpose. Thus, the antenna system can be used more flexibly.

A second aspect of the present invention provides a base station comprising a base station antenna system according to the first aspect as such or any implementation forms of the first aspect, and a base band unit configured to receive a calculated elevation and azimuth of the antenna element of the base station antenna system or configured to receive the orientation data and to calculate the elevation value and azimuth value of the antenna element of the base station antenna system based on the received orientation data. A third aspect of the present invention provides a base station comprising a plurality of base station antenna systems according to the first aspect as such or any implementation forms of the first aspect, and a base band unit configured to receive a calculated elevation and azimuth of the antenna element of each base station antenna system or configured to receive the orientation data and to calculate the elevation value and azimuth value of the antenna element of each base station antenna system based on the received orientation data.

In other words, in the second and third aspect, respectively, either the base station antenna system itself calculates both the azimuth and elevation value, or the calculation of the azimuth and elevation values happens outside the base station antenna system, namely in the base station. The calculation in the base station can, for example, be carried out based on raw sensor data provided as orientation data from the antenna system. At the base station, the azimuth and elevation values may be used for adjustments and optimizations of the antenna system during installation or operation. For instance, instead of manually estimating the azimuth and elevation of an antenna system, the calculated values can be used by service personal, for example, during setup of the antenna system. It is also possible to automatically identify multiple antenna systems at one base station by the calculated values. This allows for quicker antenna installations, for instance, because the need to check a cabling assignment to each antenna system is no longer necessary.

In a first implementation form of the second or third aspect, the base station comprises a local maintenance terminal connected to the base band unit. The local maintenance terminal is configured to display the calculated elevation and azimuth of the antenna element.

Thereby, the azimuth and elevation values of antenna elements do not need to be manually estimated or measured anymore. Instead, the received and/or calculated values can be automatically displayed to service personal at the base station, which is particularly helpful during installation or maintenance work.

In a second implementation form of the base station according to the second or third aspect as such or according to the first implementation form of the second or third aspect, the base band unit is configured to associate a network cell to the antenna element of the base station antenna system based on the calculated elevation and azimuth of the antenna element.

Thus, there is no need to check the cable assignment at the base band unit interfaces, or to otherwise manually detect, which antenna system serves which cell of a cellular network.

In a third implementation form of the base station according to the third aspect as such or according to any implementation forms of the third aspect, the base station comprises a control unit connected to the base band unit and configured to change a beam direction of the antenna element, wherein the control unit is configured to automatically compensate a deviation between the calculated elevation or azimuth of the antenna element and a predetermined elevation or azimuth by changing the beam or direction of the antenna element. Thus, the base station antenna system can be provided with a self-healing or self- compensation function of said deviations in view of planned parameters or in view of parameter changes during operation. This may particularly be of advantage if, for example, different antenna systems need to be set up pointing into different directions and/or if strong winds have moved an antenna system into other directions than desired or planned. The base station may read the current azimuth and elevation of an antenna system, and may automatically correct any deviation by controlling the antenna beam pattern or direction. A cumbersome manual recalibration of an antenna system can thus be avoided.

It is noted that if the orientation sensor outputs the orientation data to the base station, for example as raw sensor data, the orientation data may in addition to the base band unit be also processed in the control unit.

It is further noted that in the present application the term "or" is to be understood as mathematical "or" (i.e. in the meaning of and/or, and not as an exclusive or).

In a fourth implementation form of the base station according to the third implementation form of the third aspect, the antenna element has electronic beam controlling capability, and the base station control unit is configured to automatically compensate the deviation by changing the beam direction of the antenna element using electronic beam control of the antenna element. In a fifth implementation form of the base station according to the third or fourth implementation forms of the third aspect, the antenna system comprises a positioning unit configured to move or rotate the antenna element regarding a fixture of the antenna element, and the control unit is configured to automatically compensate the deviation by changing the beam direction of the antenna element by controlling the positioning unit.

Thus, by the fourth and fifth implementation forms, generally a beam direction steering capability of the antenna system is provided in the base station. This is of great advantage, because it may only be possible to roughly align the antenna system combined with the orientation sensor on an antenna tower, but then to fine adjust, or re-adjusted, the alignment by means of the beam direction steering capability. The beam direction steering can be carried out, for example, via an operation and service system connected to the base station.

Moreover, unintentional changes of the azimuth and elevation values, for example, cause by heavy wind storms, can be detected and may be automatically compensated. The orientation sensor inside the antenna system delivers the necessary orientation data, which are converted to azimuth and elevation values in the antenna system or in the base station, respectively, and may be compensated based on stored default or desired values of azimuth and elevation.

A fourth aspect of the present invention provides a communication system, comprising a base station according to the second or third aspect as such or according to any implementations forms of the second or third aspect, and an operation and service system configured to receive from the base station the calculated elevation and azimuth of said antenna element and to provide control signals to the base station for controlling a beam direction of the antenna element based on the calculated elevation and azimuth.

The azimuth and elevation values may be used in the operation and service system. A possible use includes, but is not limited to, an equipment configuration database, checking installed parameters against planned parameters, detection and compensating a drifting of the installed antenna parameters during operation, as for example caused by heavy winds that move the antenna system on a tower pole.

A fifth aspect of the present invention provides a method for controlling a beam direction of an antenna element of a base station antenna system, the method comprising: Determining azimuth and elevation of the base station antenna element, determining a difference between the determined azimuth and elevation and a predetermined azimuth and elevation for the base station antenna element, and providing, based on the determined difference a control signal to the antenna element for controlling beam direction of the antenna element. The method of the fifth aspect enables compensation of, for example, manufacturing tolerances of the base station antenna systems or compensation of offsets between a true beam direction of antenna elements and a sensing direction of the orientation sensors.

In a first implementation form of the fifth aspect, the method is for controlling a beam direction of an antenna element of a base station antenna system according to the first aspect as such or according to any implementation forms of the first aspect. It has to be noted that all devices, elements, units and means described in the present application could be implemented in the software or hardware elements or any kind of combination thereof. All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities. Even if, in the following description of specific embodiments, a specific functionality or step to be full formed by eternal entities not reflected in the description of a specific detailed element of that entity which performs that specific step or functionality, it should be clear for a skilled person that these methods and functionalities can be implemented in respective software or hardware elements, or any kind of combination thereof.

BRIEF DESCRIPTION OF DRAWINGS

The above aspects and implementation forms of the present invention will be explained in the following description of specific embodiments in relation to the enclosed drawings, in which

Fig. 1 shows an antenna system according to an embodiment of the present invention; Fig. 2 shows a bases station according to an embodiment of the present invention;

Fig. 3 shows a communication system according to an embodiment of the present invention; Fig. 4 shows a setup of base stations in a cellular network, wherein each base station includes antenna systems according to an embodiment of the present invention;

Fig. 5 shows base stations according to an embodiment of the present invention communicating in a network; and

Fig. 6 shows a flow diagram of a method according to an embodiment of the present invention. DETAILED DESCRIPTION OF EMBODIMENTS

Figure 1 shows a base station antenna system 100 for a base station according to an embodiment of the present invention. The base station antenna system 100 comprises at least one antenna element 101, which is for instance an antenna panel, and may include one or more antenna dipoles. The base station antenna system 100 also comprises at least one antenna control unit 102, which may be realized by or may include a controller or microprocessor. The antenna element 101 and the control unit 102 are preferably attached to another or integrated. For example, the antenna element 101 and the control unit 102 may be together provided in an (one and the same) antenna radome or any other kind of antenna housing.

The antenna control unit 102 comprises at least one orientation sensor, and is thus able to determine orientation data 103 indicating a current orientation of the antenna element 101. That is, the orientation data 103 may indicate a current beam direction of the antenna element 101 in the horizontal and/or vertical plane. In order to determine the orientation data 103, the control unit 102 is, for example, configured to measure with the orientation sensor a deviation of its orientation from the magnetic north pole in a horizontal plane and/or a deviation from the gravity center in a vertical plane. The orientation data may, for instance, be output as XYZ coordinates, wherein the origin of the coordinate system may be situated in the magnetic north pole. The orientation sensor may, for instance, be realized by a commercially available orientation sensor.

Figure 1 shows further examples for an azimuth 105 and elevation 104 of the antenna element 101, which are important parameters for installation and operation of the antenna system 100. Elevation 104 is defined in the vertical plane, and may be changed for an antenna element 101, for example, between -20° and +20°. Azimuth 105 is defined in the horizontal plane, and may be changed for an antenna element 101, for example, between 0° and 360°. Azimuth 105 and elevation 104 of the antenna element 101 can be precisely calculated from the orientation data 103. For example, the antenna control unit 102 may itself be configured to calculate the elevation 104 and azimuth 105 of the antenna element 101 based on the orientation data 103. In this case, the antenna control unit 102 may output the calculated azimuth 105 and elevation 104 via an antenna interface. Alternatively, the orientation sensor of the antenna control unit 102 may provide raw sensor data as the orientation data 103. In this case, the antenna control unit 102 may output the raw sensor data via an antenna interface, for example, to a base station. The antenna control 102 may also be configured to output both, the raw sensor data and the calculated azimuth 105 and elevation 104. Figure 2 shows a base station 200 according to an embodiment of the present invention, as for example used in a wireless cellular network. The exemplary base station 200 comprises three base station antenna systems 100, each constructed preferably according to the above description. The base station antenna systems 100 are each connected to a base band unit (BBU) 202 of the base station 200. The three antennas system 100 may form together with the BBU a BTS.

Each antenna system 100 includes the control unit 102 including the orientation sensor 201. The antenna control unit 102 may further comprise a controller 206 and a memory 205. In the memory 205, for example, offset information is stored. The offset information may indicate a deviation between a sensing direction of the orientation sensor 201 and a beam orientation of the antenna element 101 of the same antenna system 100. The antenna control unit 102 is preferably configured to output the stored offset information via the antenna interface, for example, together with the raw sensor data as the orientation data 103. Alternatively, the control unit 102 may calculate the elevation 104 and azimuth 105 of the antenna element 101 based on the orientation data 103 and additionally based on the stored offset information. That means, the control unit 102 is configured to take into account the offset information when calculating the azimuth 105 and elevation 104 of its antenna element 101. The control unit 102 is then further configured to output these calculated values via the antenna interface.

The offset information may be used in the calculation of azimuth 105 and elevation 104 to compensate for antenna manufacturing tolerances and/or to apply intentional beam direction offsets. An example for an intentional beam direction offset is a fixed pre-tilt value for the antenna element 101 of the antenna system 100. The fixed pre-tilt value is preferably a downtilt in the range of about 0° to 10°, more preferably about 5°. The stored offset information may particularly be used to alter (e.g. to be added or subtracted from) the orientation sensor 201 reading values, i.e. the raw sensor data. The offset information is preferably already stored in the memory 205 during antenna manufacturing and/or during a calibration process. However, it may also be possible to write the offset information into the memory 205 during operation, for example, by the base station 200.

The control unit 102 of each antenna system 100 is connected via an antenna interface to the BBU 202. Any suitable antenna interface can be used for this purpose. Interface examples include, but are not limited to, Common Public Radio Interface (CPRI), Open Base Station Architecture Initiative (OBSAI), Open Base Station Radio Interface (OBRI), and Antenna Interface Standards Group (AISG).

For each antenna system 100 of the base station 200, the azimuth 105 and elevation 104 values can be calculated based on the respectively provided orientation data 103. The calculation can either be done in the antenna systems 100 or in the base station 200, for instance in the BBU 202. The calculated antenna azimuth 105 and elevation 104 values are preferably made available for multiple applications in the base station 200.

A first example of an application is setting-up the antenna elevation 104 and azimuth 105 values during or after antenna installation. As shown in figure 2, the base station 200 may comprise a local maintenance terminal (LMT) 204 connected locally to the BBU 201. The LMT 204 can preferably be used to display the calculated elevation 104 and azimuth 105 values of one or more antenna systems 100. During the time of display, the function of radio transceivers of the base station 200 is preferably disabled, in order to prevent service persons from being exposed to RF radiation directly in front of the antennas systems 100.

A second example of an application is automatically recognizing the antenna systems 100, and preferably their assignments to respective input ports of the BBU 202. In this case, the need to check which cable is connected to which BBU 202 port is eliminated, because the azimuth 105 value of each antenna system 100 provides automatically the correct assignment of the antenna system 100 to a BBU 202 port or to a network serving cell. Preferably the BBU 202 is configured to associate a network cell with the antenna element 101 of each base station antenna system 100 based on the calculated azimuth 105 of the antenna element 101.

A third example of an application is self-healing and self-optimization of the antenna azimuth 105 and elevation 104 values. The third application example can, for example, be used with a base station antenna system 100 that has some sort of beam controlling capability. Such an antenna system 100, for instance, allows beam direction control in a vertical and/or horizontal direction. The beam direction control can be performed, for example, by adjusting passive antenna components or active antenna processing parameters. For realizing the third application example, the base station 200 comprises preferably a control unit 203 connected locally to the BBU 202. The control unit 203 may include or be a controller or microprocessor. Preferably, the control unit 203 is configured to change a beam direction of each antenna element 101. As an example for adjusting an active processing parameter, the beam direction of the antenna element 101 may be changed by using an electronic beam control of the antenna element 101. In this case the antenna element 101 has an electronic beam controlling capability. As an example for adjusting passive antenna components, the beam direction of the antenna element 101 may be changed by controlling a positioning unit configured to move or rotate the antenna element 101 in respect to, for example, a fixture of the antenna element 101. By changing the beam direction of the antenna element 101, the control unit 203 is preferably configured to automatically compensate a deviation between the calculated elevation 104 or azimuth 105 of the antenna element 101 and a predetermined elevation or azimuth, respectively, by changing the beam direction of the antenna element. The predetermined elevation or azimuth may be stored for each antenna system 100 in the control unit 203, or may be readable from the antenna system 100, for example, from the memory 205 via the antenna interface.

A fourth example of an application is using the calculated azimuth 105 and elevation 104 values in an operation and maintenance system (OSS) of a communication system 300. Such a communication system 300 is shown in figure 3 and includes at least one base station 200 as described above, and the OSS 301. The OSS 301 is configured to receive from the base station 200 the calculated elevation 104 and azimuth 105, preferably of the antenna elements 101 of all of its antenna systems 100. The OSS 301 may also be able to provide control signals to the base station 200, preferably for controlling a beam direction of the antenna elements 101 based on the calculated elevation 104 and azimuth 105 values. The OSS 301 may, for instance, carry out self- optimizing network functions (SON). The azimuth 105 and elevation 104 values delivered by the antenna systems 100 can also be used for configuration and inventory database. Also a long-term stability and deviation of these values can be monitored by the OSS 301. Serious deviations, caused, for example, by strong winds, can be easily detected by the OSS 301 through a periodic update of these values.

The orientation data 103 provided by the orientation sensors 201 may be used for an automatic correction of elevation and/or azimuth of the respective antenna elements 101. The correction may be performed during network operation via the OSS 301 or via the LMT 204. Thereby, antenna elements 101 can be repositioned according to desired beam directions remotely from the OSS 301. Alternatively, the values of azimuth 105 and elevation 104 can be changed in case of a new radio network planning.

Figure 4 shows three base stations 200 with three antenna systems 100 each. For each base station 200 the three antenna systems serve a different cell in a mobile network. Each antenna system 100 may thus be regarded as a sector antenna. In the three-sector setup shown in fig. 4, the three antenna systems 100 of each base station 200 have different azimuth 105 values. Preferably, one antenna system 100 has an azimuth of 0°, one antenna system 100 has an azimuth of 120° and one antenna system has an azimuth of 240°. However, other azimuth values could be selected if needed. Each antenna system 100 also has a well defined elevation value. The elevation values of the antenna systems 100 of one base station 200 may be identical or may differ for each served network cell.

Figure 5 shows two base stations 200 with at least one antenna system 100 each. The antenna systems 100 are preferably provided on poles or towers 500. Preferably, the antenna systems 100 of different base stations 200 serving the same network cell have the same relative elevation 104 in respect to the terrain the tower 500 stands on. Figure 5 shows, how the antenna beams are preferably focused downwards (i.e. have a downtilt) towards the cell capacity area. Preferably, the downtilt of the antenna systems 100 is between about 0° and 10°. In figure 5 the downtilt is 5° for each antenna system 100. The downtilt of each antenna system 100 is preferably selected based on at least one of: the height of the antenna system 100 over ground, the radius of the network cell it serves, the terrain profile and the level of its interference into a neighboring cell.

Fig. 6 shows a flow diagram of a method 600 for controlling a beam direction of an antenna element of a base station antenna system according to an embodiment of the present invention.

The method 600 comprises a step of 601 of determining azimuth and elevation of the base station antenna element. Furthermore the method 600 comprises a step 603 of determining a difference between the determined azimuth and elevation and a predetermined azimuth and elevation for the base station antenna element.

Furthermore the method 600 comprises a step 605 of providing, based on the determined difference a control signal to the antenna element for controlling the beam direction of the antenna element.

The method 600 may be performed using, for example, the base station 200. The present invention has been described in conjunction with various embodiments as examples as well as implementations. However, other variations can be understood and effected by those persons skilled in the art and practicing the claimed invention, from the studies of the drawings, this disclosure and the independent claims. In the claims as well as in the description the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

1. Base station antenna system (100) comprising

an antenna element (101), and

an antenna control unit (102) comprising an orientation sensor (201), the orientation sensor (201) being configured to determine orientation data (103) indicating a current orientation of the antenna element (101).

2. Base station antenna system (100) according to claim 1, wherein

the antenna control unit (102) and the antenna element (101) are arranged in an antenna radome.

3. Base station antenna system (100) according to claim 1 or 2, wherein

the orientation sensor (201) is configured to measure a deviation of its orientation from the magnetic north pole in a horizontal plane and a deviation from the gravity center in a vertical plane, and to determine the orientation data (103) based on the measured deviations.

4. Base station antenna system (100) according to one of claim 1 to 3, wherein the antenna control unit (102) is configured to calculate an elevation (104) and an azimuth (105) of the antenna element (101) based on the orientation data (103) and to provide the calculated azimuth (105) and elevation (104) via an antenna interface.

5. Base station antenna system (100) according to one of claim 1 to 4, wherein the orientation sensor (201) is configured to provide raw sensor data as the orientation data (103); and

the antenna control unit (102) is configured to provide the raw sensor data via an antenna interface.

6. Base station antenna system (100) according to one of claim 1 to 5, wherein the antenna control unit (102) comprises a memory (205), in which an offset information is stored, the offset information indicating a deviation between a sensing direction of the orientation sensor (201) and a beam orientation of the antenna element (101), wherein the antenna control unit (102) is configured to output the stored offset information via an antenna interface or to calculate an elevation (104) and an azimuth (105) of the antenna element (101) based on the orientation data (103) and the stored offset information and to output the calculated elevation (104) and azimuth (105) via the antenna interface.

7. Base station (200), comprising

a base station antenna system (100) according to one of the claims 1 to 6, and a base band unit (202) configured to receive a calculated elevation (104) and azimuth (105) of the antenna element (101) of the base station antenna system (100) or configured to receive the orientation data (103) and to calculate the elevation value and azimuth value of the antenna element (101) of the base station antenna system

(100) based on the received orientation data (103).

8. Base station (200) comprising

a plurality of base station antenna systems (100) according to one of the claims 1 to 6, and

a base band unit (202) configured to receive a calculated elevation (104) and azimuth (105) of the antenna element (101) of each base station antenna system (100) or configured to receive the orientation data (103) and to calculate the elevation value and azimuth value of the antenna element (101) of each base station antenna system (100) based on the received orientation data (103).

9. Base station (200) according to one of claims 7 to 8, wherein

the base band unit (202) is configured to associate a network cell to the antenna element (101) of the base station antenna system (100) based on the calculated elevation (104) and azimuth (105) of the antenna element (101).

10. Base station (200) according to one of the claims 8 to 9, comprising

a control unit (203) connected to the base band unit (202) and configured to change a beam direction of the antenna element (101),

wherein the control unit (203) is configured to automatically compensate a deviation between the calculated elevation (104) or azimuth (105) of the antenna element (101) and a predetermined elevation or azimuth by changing the beam direction of the antenna element (101).

11. Base station (200) according to claim 10, wherein

the antenna element (101) has electronic beam controlling capability, and the base station control unit (203) is configured to automatically compensate the deviation by changing the beam direction of the antenna element (101) using electronic beam control of the antenna element (101).

12. Base station (200) according to claim 10 or 11, wherein

the antenna system (100) comprises a positioning unit configured to move or rotate the antenna element (101) regarding a fixture of the antenna element (101); and the control unit (203) is configured to automatically compensate the deviation by changing the beam direction of the antenna element (101) by controlling the positioning unit.

13. Communication system (300), comprising

a base station (200) according to one of the claims 7 to 12, and

an operation and service system (301) configured to receive from the base station (200) the calculated elevation (104) and azimuth (105) of said antenna element

(101) and to provide control signals to the base station (200) for controlling a beam direction of the antenna element based on the calculated elevation (104) and azimuth

(105).

14. A method (600) for controlling a beam direction of an antenna element (101) of a base station antenna system (100), the method comprising:

Determining (601) azimuth (105) and elevation (104) of the base station antenna element (101);

Determining (603) a difference between the determined azimuth (105) and elevation (104) and a predetermined azimuth and elevation for the base station antenna element (101); and

Providing (605), based on the determined difference a control signal to the antenna element (101) for controlling the beam direction of the antenna element (101).

15. A computer program comprising a program code for performing, when running on a computer, the method according to claim 14.