Method and apparatus for antenna calibration control
A method is disclosed which is for controlling antenna calibration of an antenna system residing in a wireless communication network. The antenna calibration is for compensation of impairments associated with operation of the antenna system. The method comprises performing over-the-air measurements of the antenna calibration during unused symbols defined by a predetermined pattern of unused symbols, wherein the predetermined pattern of unused symbols comprises unused symbols directly preceding synchronization symbols and/or unused symbols directly following synchronization symbols. In some embodiments, the predetermined pattern comprises sequences of consecutive unused symbols. Each sequence of consecutive unused symbols which has a length exceeding a measurement length threshold may comprise one or more measurement opportunities, and each measurement may be performed during a respective measurement opportunity. According to some embodiments, the synchronization symbols are time aligned for two or more network nodes operating within the network. Such embodiments may reduce interference during the measurements.
1 . A method for controlling antenna calibration of an antenna system residing in a wireless communication network, wherein the antenna calibration is for compensation of impairments associated with operation of the antenna system, the method comprising:
performing over-the-air measurements of the antenna calibration during unused symbols defined by a predetermined pattern of unused symbols, wherein the predetermined pattern of unused symbols comprises unused symbols directly preceding synchronization symbols and/or unused symbols directly following synchronization symbols.
2 . The method of claim 1 , wherein the predetermined pattern comprises sequences of consecutive unused symbols, wherein each sequence of consecutive unused symbols comprises one or more measurement opportunities, and wherein each measurement is performed during a respective measurement opportunity.
3 . The method of claim 1 , wherein the unused symbols are symbols that are unassigned and/or undedicated and/or unallocated.
4 . The method of claim 1 , wherein the synchronization symbols are time aligned for two or more network nodes operating within the network.
5 . The method of claim 4 , wherein the unused symbols are symbols of slots comprising the one or more SSBs, and wherein each SSB consists of four symbols, and/or each of the slots comprises up to two SSBs, and/or each of the slots consists of fourteen symbols, and/or a predetermined pattern is configured to comprise between twelve and sixty-four SSBs, and/or each of the slots comprises three, four, five, or six unused symbols.
6 . The method of claim 1 , further comprising, for each of the measurements:
prior to performing the measurement and during an unused symbol, switching one or more antenna elements from transmission mode to reception mode or from reception mode to transmission mode; and/or
after performing the measurement and during an unused symbol, switching one or more antenna elements from reception mode to transmission mode or from transmission mode to reception mode.
7 . The method of claim 1 , wherein the measurements are performed using over-the-air signaling with at least one antenna element of the antenna system configured for transmission and at least one other antenna element of the antenna system configured for reception.
8 . The method of claim 7 , wherein performing the measurements comprises performing the set of measurements responsive to one or more of:
elapse of a predetermined time since performance of a previous set of measurements;
detection of a temperature change in relation to the antenna system; and
detection of deteriorating communication performance in relation to the antenna system.
9 . The method of claim 1 , further comprising, for at least one of the measurements:
determining whether the performed measurement is unreliable; and
when the performed measurement is unreliable, discarding a result of the performed measurement and repeating the measurement.
10 . The method of claim 1 , wherein the synchronization symbols are symbols of one or more synchronization signal blocks, SSBs.
11 . The method of claim 1 , further comprising dynamically controlling relative phrase and gain relations between antennas of the antenna system.
12 . An apparatus for controlling antenna calibration of an antenna system residing in a wireless communication network, wherein the antenna calibration is for compensation of impairments associated with operation of the antenna system, the apparatus comprising controlling circuitry configured to cause the apparatus to:
perform over-the-air measurements of the antenna calibration during unused symbols directly preceding synchronization symbols and/or unused symbols directly following synchronization symbols.
13 . A network node comprising:
an antenna system; and
an apparatus for controlling antenna calibration of the antenna system in a wireless communication network, wherein the antenna calibration is for compensation of impairments associated with operation of the antenna system, the apparatus comprising controlling circuitry configured to cause the apparatus to perform over-the-air measurements of the antenna calibration during unused symbols directly preceding synchronization symbols and/or unused symbols directly following synchronization symbols.
14 . The network node of claim 13 , wherein the network node is one or more of: a radio access node, a base station, an access point, a radio unit, an open radio access network radio unit.
15 . The network node of claim 13 , wherein the antenna system is an active antenna system, AAS.