Method of configuring an antenna, system, computer program and computer-readable medium

Abstract

A method of configuring an antenna configured to transmit a plurality of signals. The method comprises a step of controlling the antenna to operate using a maximum allowable transmission power parameter for the antenna as a transmission power parameter limit of two or more of the plurality of signals. The method further comprises configuring the antenna to transmit each of the plurality of signals using a respective transmission power parameter that does not exceed the transmission power parameter limit.

Description

P264726WOOO P110543-WO (1001009)Method of Configuring an Antenna, System, Computer Program and Computer- Readable MediumFIELD

[0001] The disclosure relates generally to methods and systems for configuring an antenna.BACKGROUND

[0002] Traditional antennas transmit signals according to a static radiation pattern - that is, a radiation pattern that does not change over time and distributes energy in a particular area in the same way for each transmission.

[0003] The introduction of 5G has been accompanied by advanced technologies including time-varying antennas, commonly known as Massive MIMO (multi-input and multi-output) antennas. Masive MIMO antennas are composed of many micro-antenna elements or arrays (for example, 256, 128, 64, 32, or 16 elements, although larger or different numbers may be possible). These micro-antenna elements can operate together in a coordinated manner to be able to create highly directional beams using advanced signal processing techniques. The more antennas are used, the more precise the spatial focus can be.

[0004] In Massive MIMO antennas, the radiation pattern is not fixed. Instead, it can vary rapidly over time to modify the shape of the antenna beam (beam width), the pointing direction, and the gain. This can allow energy to be directed to where it is needed — typically only towards an individual user or a group of them, which may be sparsely located in the service area. This functionality is called beamforming.

[0005] In other words, these time-varying antennas allow the steering of a radio beam towards a user to improve the temporal and spatial resource use of the communication channel, since the radiation pattern can be adjusted dynamically based on demand. These beams are thus far more directive than those of traditional antennas and can be directed only toward the positions of active users. Such solutions are also expected to be widely used in future 6G systems.

[0006] Massive MIMO beamforming can also take into account the surrounding environment. For example, signals may reflect off buildings and other obstacles, resulting in delays, attenuation and specific directions of arrival. In some cases, a direct line of sight between the antenna and a user terminal (typically a user equipment, UE) may not exist. These indirect transmission paths can be exploited by a Massive MIMO antenna to address such cases.

[0007] In order to take advantage of the multiple transmission paths, the spatial channel between the antenna elements and the user terminals should be characterised in some manner. This characterisation is commonly referred to as channel state information (CSI).P264726WOOO P110543-WO (1001009)CSI essentially represents a collection of spatial transfer functions between each antenna and each user terminal. Other techniques can be used to characterise the transmission points. The practical point is that signals transmitted in different directions combine constructively at the location of a user due to the exploitation of the channel characteristics.

[0008] The spatial diversity of Massive MIMO enables the same signal to be sent over multiple paths, which can improve a signal-to-noise ratio and allow for the reuse of the same frequency to carry different information along different paths to spatially separated users.

[0009] Another aspect of Massive MIMO, alongside beamforming and spatial diversity, is the possibility to implement of Single User MIMO (SU-MIMO) or Multi-User MIMO (MU-MIMO). The main difference between SU-MIMO and MU-MIMO lies in the number of users that can be assigned to the same radio resources (spectrum, resource element, and so on) simultaneously.

[0010] In SU-MIMO, only one user is served at a time for a specific band or portion of the band. This is illustrated in Figure 1 (scenario a). In this case, as the number of users increases, performance typically decreases because radio resources must be shared over time among all active users.

[0011] To enable all UEs to experience the same performance (speed, capacity, and so on) that is achievable with only one active user, radio resources are reused simultaneously among all users. In MU-MIMO, however, the transmission power of the Massive MIMO antenna is divided among all active beams, based on the rules implemented in the scheduler of the technology provider. In particular, whilst the radiation pattern in Massive MIMO antennas is not fixed, the maximum transmittable power remains unchanged. For example, assuming that the scheduler proportionally distributes power among spatially separated beams, in the case of 4 users, the power of each beam power will be 6 dB lower (reduced by a quarter) compared to a SU-MIMO scenario. The MU-MIMO scenario is illustrated in scenario b of Figure 1.

[0012] This phenomenon highlights one of the characteristics of MU-MIMO. As the number of connected users increases, the power transmitted to each user decreases, reducing the signal-to-noise ratio (SNR). Therefore, under high traffic conditions, precisely when the network should deliver maximum performance, the SNR is reduced.

[0013] For traditional antennas, the radiation pattern and antenna gain, combined with input power and channel propagation characteristics, determines the distribution of the electromagnetic field (EMF) around the radiating system. However, with Massive MIMO antennas, there is no direct proportionality between the total transmitted power and the Equivalent Isotropic Radiated Power (EIRP) along the direction of the user.

[0014] The complex space-time configuration of the field radiated by Massive MIMO antennas, which can provide unprecedented efficiency in the use of radio resources, hasP264726WOOO P110543-WO (1001009)resulted in updates to the methods for estimating the EMF level generated by a 5G base station. These updates are in consideration of regulatory compliance (for example, to comply with requirements regarding human health) while also enhancing network performance.

[0015] One example of new EMF estimation methodologies for Massive MIMO antennas have been established in International Electrotechnical Commission (IEC) standard 62232 and in Technical Report (TR) IEC TR 62669.

[0016] In the IEC standard 62232, the IEC recommends an “envelope diagram” as a tool for conducting a predictive EMF assessment of the electromagnetic field generated by a Massive MIMO antenna. The envelope diagram is obtained by taking, for each direction, the highest gain value among all possible beams that the antenna can synthesise in that direction. This is illustrated in Figure 2. The envelope diagram is, however, a purely theoretical representation that differs from real-world conditions. Thus, antenna configurations that are implemented based on this EMF estimation may not make effective use of the available resources of the network.

[0017] Therefore, methods and systems that overcome these issues is desirable.SUMMARY

[0018] A transmitter or antenna is able to send two or more signals at a time (or within a certain time period) with a radio wave frequency. A limit for the total power or strength with which the transmitter can send signals instantaneously or within a certain time period is known. That is, according to the limit, the transmitter cannot transmit across the sum of signals more than the limit. The limit may be calculated, determined or otherwise identified based on antenna regulations (including regulations for antenna power or strength based on human health concerns).

[0019] The transmitter power or strength limit is applied to the signals that the transmitter will send. That is, the limit is not used as a limit for the transmitter itself but rather a signal that the transmitter will transmit or is transmitting. This allows the transmitter to send signals with a higher power or strength than would otherwise be allowed, but transmitters capable of sending two or more signals at a time are typically not transmitting the signals in the same direction. The limit can thus still be obeyed in practice.

[0020] The transmitter is then arranged to transmit the two or more signals with a power or strength up to the signal limit. The transmitter may not send all or any signals with the maximum possible power or strength, but the transmission strength or power may still be more than would be possible when using the limit as a transmitter (as opposed to a signal) limit.

[0021] In accordance with a first aspect, there is provided a method of configuring an antenna configured to transmit a plurality of signals, the method comprising steps of:P264726WOOO P110543-WO (1001009)controlling the antenna to operate using a maximum allowable transmission power parameter for the antenna as a transmission power parameter limit of two or more of the plurality of signals; andconfiguring the antenna to transmit each of the plurality of signals using a respective transmission power parameter that does not exceed the transmission power parameter limit.

[0022] This can allow an antenna to transmit signals having an increased signal-to-noise ratio, even under high traffic conditions, improve network coverage and performance of the antenna, whilst also conforming to regulations regarding human health.

[0023] In some examples, the two or more of the plurality of signals may comprise each of the plurality of signals. In other words, the maximum allowable transmission power may be a limit for each of the signals to be transmitted.

[0024] In further examples, a sum of the transmission power parameters may be greater than the maximum allowable transmission power parameter for the antenna. Thus, the signal-to-noise ratio of the signals can be improved, and the antenna can provide greater coverage within a telecommunications network.

[0025] Whilst the sum of transmission power parameter limits for the two or more of the plurality of signals will exceed the maximum allowable transmission power parameter for the antenna (by virtue of applying the limit to at least two signals), the power parameter for transmitting the plurality of signals need not exceed the maximum allowable transmission power parameter for the antenna. For instance, the maximum allowable transmission power parameter for the antenna may be 50W, but for two signals, the two signals may be transmitted with a power parameter of less than or equal to 25W (although the antenna is still authorised to transmit the two signals with a greater power parameter).

[0026] In some implementations, at least one of the transmission power parameters may be equal to the transmission power parameter limit. It may not be possible to transmit all signals at the transmission power parameter limit due to physical limitations of the antenna, but this may allow at least one signal to be transmitted with an improved or optimised signal-to-noise ratio. Even in cases where only one signal can be transmitted at the transmission power parameter limit, this may still represent an overall improvement or optimisation of the signal-to-noise ratio, coverage of the network and / or network resource use. For example, a user may be sufficiently close to the antenna that a higher power parameter need not be used for one or more signals.

[0027] In some examples, each of the transmission power parameters may be equal to the transmission power parameter limit. This may allow an improvement for the signal-to-noise ratio of all transmitted signals.P264726WOOO P110543-WO (1001009)

[0028] In further implementations, configuring the antenna may comprise determining a transmission power parameter for one or more of (optionally, each of) the plurality of signals. For example, it may not be possible due to the physical limitations of the antenna to transmit all signals at the transmission power parameter limit, or a lower transmission power parameter may be more appropriate for other reasons (for example, a user is sufficiently close to the antenna). Thus, determining a transmission power parameter limit for one or more of the plurality can improve network resource use.

[0029] In yet further examples, when a sum of the transmission power parameter limits for the two or more of (optionally, each of) the plurality of signals exceeds a usable transmission power parameter of the antenna, the determining may comprise determining a transmission power parameter for the one or more of (optionally, each of) the plurality of signals such that the sum of the determined transmission power parameters does not exceed the usable transmission power parameter of the antenna. This may allow further improvement or optimisation of network resource use.

[0030] In some implementations, the transmission power parameter may correspond to a power or equivalent isotropic radiated power, EIRP, radiation intensity, signal intensity, RF field strength or power density.

[0031] Optionally, the plurality of signals may comprise a plurality of antenna beams, layers or patterns in which an antenna radiates (or receives) electromagnetic energy. Such signals may typically be constrained in a particular direction (rather than being radiated in all directions) or time-varying and so may be particularly useful for implementing within the method.

[0032] In some examples, the method may further comprise, prior to the configuring, identifying whether a portion of a first antenna beam, layer or pattern is expected to intersect with a portion of a second antenna beam, layer or pattern. Whilst it can generally be assumed that a plurality of signals will be transmitted in different directions, there may be cases where this should be confirmed (for example, to confirm compliance with EMF regulations).

[0033] The identifying may comprise whether any portion of the plurality of antenna signal overlaps or is expected to overlap with any other portion of the plurality of antenna signals (for example, where there are more than two signals or beams).

[0034] Optionally, the identifying may comprise determining whether a main lobe of the first antenna beam, layer or pattern is expected to intersect a secondary lobe of the second beam, layer or pattern. A secondary lobe may be a signal transmitted with a lower power parameter compared to a main lobe but may nevertheless cause an intersecting main lobe of another antenna beam to exceed the transmission power parameter limit if not accounted for.P264726WOOO P110543-WO (1001009)

[0035] In some examples, the method may further comprise, in response to identifying that the portion of the first antenna beam, layer or pattern is expected to intersect with the portion of a second antenna beam, layer or pattern, determining a first transmission power parameter for the first antenna beam, layer or pattern and a second transmission power parameter for the second antenna beam, layer or pattern such that the resulting transmission power parameter in the region of intersection does not exceed the transmission power parameter limit. This can ensure that EMF regulations are conformed to whilst still allowing the signal-to-noise ratio of the signals and network coverage to be improved.

[0036] In some examples, multiple intersections (for example, between different beams or different portions of the same beams) may be identified. In this case, transmission power parameters may be determined to take into account the multiple intersections.

[0037] Preferably, the antenna may comprise a multi-input and multi-output, MIMO, antenna (including a Massive MIMO antenna), a beamforming antenna or phase array antenna. MIMO technology is a technology used with traditional antennas that can allow multiple data signals to be sent and received simultaneously over the same radio channel. Massive MIMO is a further development of this technology according to which an antenna can steer a signal or beam to focus a signal in a specific direction.

[0038] The MIMO antenna may be configured to operate as a single user MIMO antenna or and / or a multi-user MIMO antenna.

[0039] In some examples, the maximum allowable transmission power parameter for the antenna may be defined based on an electromagnetic field level estimation and / or an electromagnetic exposure limit for a human. The estimation or exposure limit may be as defined in IEC standard 62232 and / or TR IEC TR 62669, but other derivations are possible (for example, based on national legislation).

[0040] In some examples, the method may further comprise transmitting the plurality of signals with according to the configured transmission power parameters.

[0041] In accordance with a second aspect, there is provided a system configured to implement any method previously discussed. The system may comprise a beamforming system or another system for generating radiation patterns or layers.

[0042] The system may comprise an antenna. The antenna may comprise a MIMO antenna (including a Massive MIMO antenna), a beamforming antenna or phase array antenna. The MIMO antenna may comprise a SU-MIMO antenna, a MU-MIMO antenna or both.

[0043] The system may comprise a module configured to dynamically allocate resources to the systems. The module may be in communication with and may control the antenna.

[0044] The methods described above may be implemented as a computer program comprising instructions to operate a computer or computer system. The computer program may be stored on a computer-readable medium, which may be non-transitory.P264726WOOO P110543-WO (1001009)

[0045] The computer system may include a processor, such as a central processing unit (CPU). The processor may execute logic in the form of a software program. The computer system may include a memory including volatile and non-volatile storage medium. The different parts of the system may be connected using a network (e.g. wireless networks and wired networks). The computer system may include one or more interfaces. The computer system may contain a suitable operating system such as UNIX (RTM) (including Linux (RTM)), Windows (RTM), for example.

[0046] It should be noted that any feature described herein may be used with any particular aspect or embodiment of the invention. Moreover, the combination of any specific apparatus, structural or method features is also provided, even if that combination is not explicitly disclosed.

[0047] The invention will now be described with reference to the attached drawings depicting different embodiments thereof, the drawings being provided purely by way of example and not limitation.BRIEF DESCRIPTION OF DRAWINGS

[0048] The invention may be put into practice in a number of ways, and preferred embodiments will now be described by way of example only and with reference to the accompanying drawings, in which:

[0049] Figure 1 shows a schematic diagram of a system implementing a single user multiinput and multi-output method and a multiple user multi-input and multi-output method;

[0050] Figure 2 illustrates an electromagnetic field estimation method using an envelope diagram;

[0051] Figure 3 shows a flowchart of a method of configuring an antenna configured to transmit a plurality of signals according to embodiments of the disclosure;

[0052] Figures 4A to 4C illustrate exemplary regions of intersection of a plurality of signals transmitted by an antenna that may be accounted for according to embodiments of the disclosure;

[0053] Figure 5 illustrates an antenna configured to transmit a signal according to a static (unchanging) radiation pattern;

[0054] Figure 6 shows a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for single user multi-input and multi-output;

[0055] Figure 7 illustrates a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for single user multi-input and multioutput according to an embodiment of the disclosure;

[0056] Figure 8 shows a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for single user multi-input and multi-output;P264726WOOO P110543-WO (1001009)

[0057] Figure 9 illustrates a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for single user multi-input and multioutput according to an embodiment of the disclosure;

[0058] Figure 10 shows a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for multiple user multi-input and multi-output;

[0059] Figure 11 illustrates a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for multiple user multi-input and multi-output according to an embodiment of the disclosure;

[0060] Figure 12 shows a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for multiple user multi-input and multi-output;

[0061] Figure 13 illustrates a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for multiple user multi-input and multi-output according to an embodiment of the disclosure;

[0062] Figure 14 shows a schematic diagram of a system comprising an antenna configured to transmit and receive a plurality of signals for constructive interference for multiple user multi-input and multi-output according to an embodiment of the disclosure; and

[0063] Figure 15 shows a schematic diagram of a system according to an embodiment of the disclosure.

[0064] It should be noted that the Figures are illustrated in schematic form for simplicity and are not necessarily drawn to scale. Like features are provided with the same (or similar) reference numerals.DESCRIPTION OF PREFERRED EMBODIMENTS

[0065] In some cases, a maximum configurable or allowable transmission power parameter of an antenna (for example, an EMF power), and therefore the usable power, is lower than the maximum power that the antenna can actually transmit (a maximum transmittable power). This is typically to comply with EMF limits or other regulatory limits, which may be in place to limit human exposure to radio frequency signals. This is because exposure to increased field strengths can cause biological tissues to heat up and the frequencies used may also have other negative biological consequences, such as tissue damage, for example. However, but other motivations or reasons for using a reduced power parameter are possible and the methods and systems discussed herein may be used to increase the transmitted power parameter in view of such motivations or reasons as well.

[0066] The maximum transmittable power represents a physical value defined by the product and may be the maximum power that an amplifier of the antenna can transmit. Different products may thus have different maximum transmittable power values.P264726WOOO P110543-WO (1001009)

[0067] According to current methods of antenna configuration, a single parameter for antenna transmission is defined, generally referred to as maximum configurable power (Pmax), which represents the total maximum power that a particular antenna is allowed to transmit. Other names may be used by different vendors, but the purpose of the parameter is the same - to limit how much power the antenna can transmit, regardless of whether the antenna is actually capable of transmitting more (or less) power.

[0068] This Pmax parameter may be suitable for traditional antennas, where the radiation pattern remains static and so the power is radiated in all directions to all users within the area that the antenna covers. However, in the case of Massive MIMO, and particularly SU-MIMO or MU-MIMO antennas, the Pmax power is divided among all the beams or signals generated by the antenna, as discussed above, meaning that each user receives a weaker transmission signal compared to a traditional antenna. This results in a reduction in the signal-to-noise ratio (SNR) and poorer coverage (since the signal cannot travel as far). Thus, whilst Massive MIMO antennas, as well as other types of variable pattern antennas including (for example) a beamforming antenna or phase array antenna, can offer advantages, current assumptions and implementations limit the ability to make use of these advantages.

[0069] In particular, as illustrated by the envelope diagram in Figure 2, the horizontal compliance distance depends on the maximum gain of a single beam, and the vertical and transverse compliance distances depend on the maximum angles at which the antenna can direct the beams. This makes the envelope diagram a purely theoretical representation that differs from real-world conditions, as it does not consider the distribution of power among active beams at any given moment, nor the spatial diversity, beamforming, and MU-MIMO functionalities typical of Massive MIMO, which can concentrate the signal in specific direction and / or sub-regions of the coverage area. Thus, antenna configurations that are implemented based on this EMF estimation may not make effective use of the available resources of the network.

[0070] The present disclosure relates to the definition and use of a new parameter that represents a maximum transmission power parameter for each signal transmitted by an antenna. This parameter can allow service quality to be improved whilst still complying with regulatory limits on electromagnetic fields. This new parameter may be referred to herein as a maximum beam power parameter or maximum signal power parameter, since it defines a transmission power parameter limit on a per beam or per signal basis. Other names may be used without altering the implementation of this parameter. It will also be appreciated that where the term maximum beam power parameter is used, the signal transmitted from an antenna may nevertheless be a signal (rather than a beam per se) and likewise that where the term maximum signal power parameter is used, the signal may specifically be a beam.P264726WOOO P110543-WO (1001009)

[0071] In short, an antenna (for example, a Massive MIMO antenna) is configured to transmit, for two or more (preferably each) beam, signal, layer or pattern in which an antenna radiates electromagnetic energy, up to a maximum allowable transmission power parameter of the antenna. If the sum of usable powers for each beam exceeds the maximum transmittable power parameter of the antenna, the transmission power parameter can be distributed among the active beams or signals. This may ensure that the configured power parameter per signal does not exceed the limit set by maximum signal power parameter (MSPP). It may also be checked that such beams or signals are steered in different directions to further confirm compliance or implement any adaptions to conform with the limit.

[0072] The MSPP may be defined based on a power value or power-related value. For example, the MSPP may correspond to a power (amount of energy), an equivalent isotropic radiated power (EIRP), radiation intensity, signal intensity, RF field strength or power density.

[0073] The EIRP takes into account antenna gain, as well as the power. In particular, EIRP is a measure of the power radiated by an antenna in a particular direction, taking into account an output power of the transmitted and an antenna gain in that direction. Although embodiments discussed herein may be discussed primarily with respect to a per signal power limit (MSPP), it will be appreciated that a maximum beam or signal EIRP can be used without affecting the validity or implementation of the embodiments discussed herein. The term maximum transmission power parameter encompasses both measurements of power, as well as other possible power measurements.

[0074] RF field strength may already be used for assessing a communication link between a transmitter (antenna) and a receiver, so may be a useful measurement on which to base antenna limits. Radiation intensity and signal intensity may similarly be implemented.

[0075] The maximum transmission power parameter approach discussed herein can allow for improving or optimising the SNR of a signal and improving coverage of the network, while complying with the regulatory limits on electromagnetic fields. This can provide benefits both at the cell edges and in indoor environments.

[0076] Figure 3 illustrates a flowchart of a method of configuring an antenna that is configured to transmit a plurality of signals. The antenna may be a multi-input and multioutput, MIMO, antenna (including a Massive MIMO antenna), a beamforming antenna or phase array antenna. The MIMO antenna may be configured to operate as a SU-MIMO antenna, a MU-MIMO antenna or both.

[0077] The antenna may form part of a telecommunications system within a telecommunications network. The system may be 3G, 4G, 5G, 6G system, and so on. For example, the antenna may be comprised within a base station and the base station may beP264726WOOO P110543-WO (1001009)a 3G, 4G, 5G or 6G base station, or beyond. The base station may be a NodeB, eNodeB or gNodeB, for instance. It will be appreciated that the methods discussed herein may be implemented with types of base station.

[0078] At step 301 , the antenna is controlled (for example, configured, instructed or otherwise adapted) to operate using a maximum allowable transmission power parameter for the antenna as a transmission power parameter limit of each of the plurality of signals. The maximum allowable transmission power parameter may be a limit based on an electromagnetic field level estimation and / or an electromagnetic exposure limit for humans. The maximum allowable transmission power parameter may otherwise be predefined.

[0079] In other words, at step 301 , the antenna is controlled to allow the antenna to transmit a signal with a transmission power parameter up to the transmission power parameter limit, rather than using the maximum allowable transmission power parameter for the antenna as a total transmission power parameter limit for the totality of signals to be transmitted (instantaneously or within a time period). Although this means that the antenna can, at least in theory, transmit more than the maximum allowable transmission power parameter when transmitting a plurality of signals, exposure limits or other regulatory limits can still be obeyed. This is because, in antennas capable of transmitting a plurality of signals and / or a time varying radiation pattern, beam or layer, it can be assumed that the signals are being transmitted in different directions (users are unlikely to be sufficiently close to cause overexposure by transmitting multiple signals at the maximum allowable transmission power parameter value).

[0080] At step 302, the method may further comprise identifying whether a portion of a first signal is expected to intersect with a portion of a second signal. Whilst it can generally be assumed that a plurality of signals will be transmitted in different directions, there may be cases where this should be confirmed. For example, when multiple beams are generated, such as in beamforming systems or Massive MIMO antenna arrays, the transmitted power parameter in each direction may need to account not only for a main lobe of the beam or signal pointing in that direction, but also for side lobes (or secondary lobes) of other beams or signals that overlap or interest in that direction. This may be necessary to ensure compliance with EMF limits and avoid exceeding the maximum allowed power parameter. The main lobe is a primary beam that carries the most energy and is directed toward the desired target or direction. The side lobes (also known as secondary lobes) are unintended or undesired radiation patterns that occur in directions other than the main lobe, at lower power levels.

[0081] Accordingly, step 302 may comprise determining whether a main lobe of a first antenna beam is expected to intersect a secondary lobe of a second beam. OtherP264726WOOO P110543-WO (1001009)intersections (for example, a main lobe of a first beam with a main lobe of a second beam) may also or instead be determined.

[0082] It will also be appreciated that the plurality of signals may include three or more antenna beams, layers or patterns in which the antenna radiates or receives electromagnetic energy. Accordingly, step 302 may comprise identifying whether any portion of the plurality of antenna signal overlaps or is expected to overlap with any other portion of the plurality of antenna signals. For instance, step 302 may comprise identifying that one signal is expected to intersect or overlap with another signal or more than one signal, or that multiple signals are expected to overlap with one or more other signal.

[0083] Optionally, at step 303, the method may further comprise, in response to identifying at step 302 that a portion of a signal or beam is expected to intersect with a portion of another signal, determining a first transmission power parameter for the signal and a second transmission power parameter for the another signal, such that the resulting transmission power parameter in the region of expected intersection or overlap does not exceed the transmission power parameter limit. Where step 302 involves identifying multiple intersections, a plurality of transmission power parameters may be determined, such that the resulting transmission power parameter in the regions of expected intersection does not exceed the power parameter limit. The transmission power parameters for the signals may be determined algorithmically (including by machine learning algorithms).

[0084] At step 304, the method further comprises configuring the antenna to transmit the plurality of signals using a transmission power parameter that does not exceed the transmission power parameter limit. In other words, each transmitted signal may be transmitted with a transmission power parameter up to and including the transmission power parameter limit. However, the signals need not and may not be transmitted at the transmission power parameter limit value.

[0085] For example, whilst the sum of transmission power parameters for the plurality of signals may be greater than the maximum allowable transmission power parameter for the antenna, the transmission power parameter of one or more of the plurality of signals may nevertheless be less than the limit. One example in which this is the case will be discussed with reference to Figure 9.

[0086] In some examples, at least one of the transmission power parameters may be equal to the transmission power parameter limit. In further examples, each of the transmission power parameters is equal to the transmission power parameter limit.

[0087] Step 304 may comprise determining a transmission power parameter for one or more (preferably each) of the plurality of signals. This may occur where step 302 (and therefore step 303) does not take place, or where no intersection was identified in step 302 (and therefore step 303 again does not take place). In other examples, only some of the pluralityP264726WOOO P110543-WO (1001009)of signals may be expected to intersect, so transmission power parameters for one or more non-intersecting signals may still be determined.

[0088] In some examples (which will be discussed in further detail with reference to Figures 9 and 13), a sum of the transmission power parameter limits for the plurality of signals may exceed a usable transmission power parameter of the antenna. This may be a hardware limit of the antenna for example. Accordingly, different antennas and different types of antenna may have different values of useable transmission power parameter. In this case, the determining in step 304 may comprise determining a transmission power parameter for each of the plurality of signals such that the sum of the determined transmission power parameters does not exceed the usable transmission power parameter of the antenna.Again, this may be determined algorithmically (including by machine learning algorithms).

[0089] Figures 4A, 4B and 4C illustrate exemplary regions of overlap or intersection that may be identified at step 302 and for which transmission power parameters may be determined at step 303. It will be appreciated that other forms of overlap are possible and that other beam or signal shapes may be used.

[0090] Figure 4A shows a system comprising an antenna 402 that is configured to transmit a first signal 404 and a second signal 406. The directions of transmission of the first and second signals 404, 406 result in a region of overlap (or expected region of overlap) 403 and this may be identified at step 302. The first and second signals 404, 406 may comprise secondary lobes (not shown for clarity).

[0091] At step 303, a transmission power parameter for the first signal 404 is determined and a transmission power parameter for the second signal 406 is determined, such that the transmission power parameter in the region of overlap 403 does not exceed the transmission power parameter limit. The transmission power parameters for the signals 404, 406 may be determined algorithmically (including by machine learning algorithms).

[0092] Figure 4B shows another system comprising an antenna 402 that is configured to transmit a plurality of signals 404, 406, 408. The signals 404 and 406 are as described above with reference to Figure 4A, resulting in a region of overlap 403. However, the signal 408 has a wider spread than the signals 404 and 406 and encompasses both of the signals 404 and 406. This results in a region of overlap 409, which comprises the signals 404 and 406 (including their overlap 403). The configured transmission power parameters for the signals 404, 406, 408 may therefore be lower than the transmission power parameters for the signals 404 and 406 illustrated in Figure 4A.

[0093] Figure 4C shows a further system comprising an antenna 402 configured to transmit first and second signals 404 and 406 in an example where a secondary lobe 406a is expected to intersect with the signal 404. The signal 404 may also have secondary lobes (not shown for clarity). Since in this case, only the secondary lobe 406a may intersect withP264726WOOO P110543-WO (1001009)the signal 404, the transmission power parameter of the signal 404 may not need to be adjusted as much as in the examples illustrated in Figures 4A and 4B.

[0094] The distinction between the traditional scenario and methods discussed herein in which a transmission power parameter limit for each beam or signal is utilised will now be illustrated with reference to Figures 5 to 14, based on exemplary scenarios.

[0095] Figure 5 illustrates a traditional antenna 502 that transmits a static (unchanging) signal 504. In this example, the maximum transmittable or usable power parameter of the antenna 502 (that is, the power parameter that it is physically capable of transmitting) is 200W. However, due to EMF regulations, Pmax (that is, the power that the antenna 502 is authorised or configured to transmit) is set to 100W. In this case, Pmax is derived from the EMF assessment defined by IEC 62232, but other derivations are possible.

[0096] Traditionally, this condition results in configuring the antenna 502 to operate according to a transmission power limit to ensure that the EMF limit is respected. In this example, based on the values noted, this would result in a transmission power limit of 100W (but it will be understood that other limit values may result in other scenarios). In other words, the configured maximum transmission power of the antenna is set to be equal to the maximum allowable transmission power parameter. Since the antenna 502 transmits a static beam over a defined area, this configuration may be appropriate.

[0097] Figure 6 illustrates an antenna 602 that is a capable of producing a plurality of signals for transmission for SU-MIMO. As with the antenna 502 described with reference to Figure 5, the maximum transmittable power parameter of the antenna 602 is 200W and again, according to EMF regulations, the maximum allowable transmission power parameter (MATPP) is 100W (although, again, different values may be used based on, for example, the antenna being of a different type or a different Pmax derivation). As with antenna 502, the antenna 602 has been configured to utilise the MATPP as a maximum transmission power parameter of the antenna (that is, the antenna is configured such that it cannot transmit more than 100W).

[0098] As discussed above, in the case of SU-MIMO, the maximum transmission power parameter of 100W will be distributed among the active beams according to rules of an antenna scheduler. Figure 6 illustrates two possible distribution scenarios for the antenna 602, which is configured to transmit two distinct beams 604, 606 that reflect off environmental clutter 620 to combine constructively at a location of a user 610. The environmental clutter 620 is illustrated in Figure 6 by buildings but it will be appreciated that other objects or features of a landscape may cause reflections.

[0099] There is no direct line of sight between the antenna 602 and the user device 610 in Figure 6, but it will be appreciated that there may be in other examples (for instance, as illustrated in Figures 8 and 9).P264726WOOO P110543-WO (1001009)

[0100] In the first scenario, the available 100W is equally distributed between the beams 604, 606. In the second scenario, 70W is allocated to the beam 606 and 30W is allocated to the beam 604. Other distributions are possible, but the sum of the transmission power parameters of each beam will not exceed 100W, due to the antenna configuration.

[0101] In other words, the EMF legislation is respected by assuming that, for each beam or signal, the power parameter is being transmitted across the whole of a defined, unchanging area (as discussed with reference to the envelope diagram in Figure 2) and configuring the Pmax accordingly to ensure that the antenna 602 does not reach the MATPP in any direction. However, this scenario impacts performance of the antenna 602 and the network, as the SNR is lowered.

[0102] In contrast, as shown in Figure 7, by setting the MSPP parameter, which defines a transmission power parameter limit of each of a plurality of signals, to 100W for each beam 704, 706, the SNR, coverage and performance of the antenna 702 and the network can be improved with respect to the conventional scenario without breaching electromagnetic field regulations. This is because, in contrast to the traditional antenna scenario described with reference to Figure 5, signals from a Massive MIMO antenna (or another type of antenna that can have a dynamic radiation pattern) can be assumed to be transmitted in different directions. Thus, even when the transmission power parameter of each signal is increased, the regulations can be respected.

[0103] In the case described with reference to Figure 7, the MSPP can be set to 100W for each beam because the sum of the transmission power parameters of the signals is equal to or less than the maximum transmittable power parameter of the antenna 702 (100W for each beam totals 200W for the antenna 702). Figures 8 and 9, on the other hand, illustrate an example scenario in which the sum of the transmission power parameters would exceed the maximum transmittable power of an antenna 802, 902 (according to traditional methods and according to the methods discussed herein, respectively).

[0104] In particular, the maximum transmittable power of the antenna 802, 902 is 200W in the example shown in Figures 8 and 9. The MATPP may be 90W due to EMF regulations, the value of which may be derived from an EMF assessment defined by international or national law. The antenna 802, 902 is configured to transmit three signals or beams 804-806, 904-906 that will combine constructively at a user location 610.

[0105] According to conventional methods, these conditions would lead to Pmax being set to 90W and being distributed amongst the three beams 804, 805, 806 according to antenna scheduler rules. Two possible distribution scenarios are shown in Figure 8: one in which the transmission power parameter is divided equally amongst the three beams 804, 805, 806; and one in which one beam 805 is configured to transmit 40W and the beams 804 and 806 are operated with a maximum transmission power or 20W. In the latter scenario, the fullP264726WOOO P110543-WO (1001009)available 90W power is not utilised by the antenna 802. Other scenarios are possible based on the scheduler (which may be a NodeB scheduler), but the total available power will always be limited to 90W in this example according to conventional methods.

[0106] Referring now to Figure 9, by utilising the MATPP as a transmission power parameter limit per beam or signal, the antenna 902 can, at least in theory, dedicate up to 90W to each active signal or beam 904, 905, 906. However, since the sum of the transmission power parameter limit for three beams would exceed the maximum transmittable power of the antenna 902 (since 90W for three beams totals 270W and the antenna 902 is physically capable of transmitting a maximum of 200W in this example), it is not possible to transmit each beam or signal with a power parameter of 90W. Instead, the available transmission power parameter is distributed across the three beams 904, 905, 906 according to the transmission power parameter limit. In the scenario illustrated in Figure 9, the available transmission power parameter is distributed equally amongst the beams to provide a transmission power parameter of 66.66W per beam. This results in a 3dB improvement in signal coverage compared to the system illustrated in Figure 8. It will be appreciated that other distribution schemes may be implemented by the scheduler (which may be a NodeB scheduler). For example, at least one of the transmission power parameters may be equal to the transmission power parameter limit (for instance, the first signal 704 may be transmitted at 100W and the second and third signals 905, 906 may be transmitted at 50W each). However, in all cases, the total available power will be limited to 200W in this example based on the physical limits of the antenna 902.

[0107] Figure 10 shows a system comprising an antenna 1002 configured to operate as a MU-MIMO antenna and having two active beams 1004, 1006. As with the previous examples, the maximum transmittable power of the antenna 1002 in this example is 200W. The MATPP may be 100W due to EMF regulations or other health-related regulations. This value may be derived from an EMF assessment defined by international or national law.

[0108] Since the antenna 1002 is configured to operate using the MATPP as a limit for the antenna 802, the transmission power parameter value is split across the two beams 1004, 1006. Two exemplary distributions are shown in Figure 10: an equal split between the beams 1004, 1006; and assigning up to 70Wto the first beam 1004 and up to 30W to the second beam 1006. Thus, up to 200W that the antenna 1002 is capable of transmitting is not being used. As the number of connected users increases, the power that can be transmitted to each user 1010 decreases, further reducing the SNR.

[0109] It will be appreciated that, although the user 1010 is indicated as being in an indoor environment, the user 1010 may be outside and, as illustrated in Figures 6 to 9, some signals may be reflected to combine constructively at the location of the user 1010.P264726WOOO P110543-WO (1001009)

[0110] Figure 11 illustrates a system comprising an antenna 1102 configured to operate as a MU-MIMO antenna and having two active beams 1104, 1106, in which the methods discussed herein are used. In particular, the maximum allowable transmission power parameter is used as a MSPP parameter, such that up to 100W can be allocated to both the first beam 1104 and the second beam 1106. The SNR and performance of the network can therefore be increased, whilst also conforming to EMF regulations.

[0111] Although Figures 10 and 11 illustrate a single signal or beam being transmitted to a single user for simplicity, it will be appreciated that there may be multiple transmission signals for one or more users (for example, as shown in Figures 6 to 9). This will be discussed in more detail with reference to Figure 14.

[0112] Figure 12 illustrates a system similar to that of Figure 11 that comprises an antenna 1202 configured to operate as a MU-MIMO antenna. The antenna 1002 is configured to transmit four signals or beams 1204-1207. As with the previous examples, the maximum transmittable power of the antenna 1202 in this example is 200W. The MATPP in this example may be 100W due to EMF regulations (which again, may be derived from an EMF assessment defined by international or national law). As a result, each beam can transmit with a transmission power of up to 25W, since the Pmax parameter (which is set as the MATPP) is divided across each active beam 1204-1207. It will be understood that other distributions of the Pmax parameter may be defined or configured by the antenna scheduler, but the sum of the power parameters for the beam will be limited to the MATPP.

[0113] Figure 13 illustrates the same system shown in Figure 12, with the exception that the antenna 1302 is configured to use the MATPP as a transmission power parameter limit on a per signal or beam basis. Since the maximum transmittable power of the antenna is 200W though, the antenna 1302 cannot transmit each beam 1304-1307 with a power of 100W (indicated by the solid line). In the example shown in Figure 13, the transmittable power is divided equally across the four active beams 1304-1307 such that each beam 1304-1307 is transmitted with a transmission power parameter of 50W (indicated by the dashed line). In this case, this results in a 3dB improvement in signal coverage with respect to the system illustrated in Figure 12. Other scenarios in which the transmittable power is not divided equally may also be implemented.

[0114] Figure 14 illustrates a system comprising an antenna 1402 configured to operate in a MU-MIMO mode. In MU-MIMO, the transmission channel for a user can be calculated, which can enable the use of multiple transmission beams or signals for a user. In the system illustrated in Figure 14, there is a plurality of users 1410, 1412. A first user 1410 is assigned a first plurality of active beams 1404-1406 (in Figure 14, three active beams, although it will be appreciated that more or fewer beams could be used). A second user is assigned aP264726WOOO P110543-WO (1001009)second plurality of active beams 1414-1416 (again, in Figure 14, three active beams, but a different number of active beams could be used).

[0115] Some of the active beams 1404, 1406, 1414, 1416 are reflected off environmental clutter 1420 to reach the users 1410, 1412. The environmental clutter 1420 is illustrated in Figure 14 as buildings but it will be appreciated that other objects or features of a landscape may cause reflections (for example, walls of a valley). The remaining active beams 1405, 1415 have a line-of-sight to the users 1410, 1412. The first plurality of active beams 1404-1406 combine constructively at the first user 1410 and the second plurality of active beams 1414-1416 combine constructively at the second user 1412.

[0116] The maximum transmittable power of the antenna 1402 in this example is 200W and the MATPP is 90W, based on a regulation standard. In a traditional case in which the antenna 1402 is configured to operate with an antenna transmission power parameter limit of the MATPP (that is, Pmax being set to 90W), the 90W would be distributed amongst the six active beams 1404-1406, 1414-1416.

[0117] In contrast, with the approaches proposed herein, up to 90W can be assigned to each active beam 1404-1406, 1414-1416. Since the sum of the transmission power parameter in this case would exceed the maximum transmittable power of the antenna 1402 in this case though (90W for 6 beams totals 540W), the maximum transmittable power of the antenna 1402 is distributed across the active beams 1404-1206, 1414-1416 according to the limit. This approach allows for improved or optimised coverage, SNR and performance, whilst also complying with the regulatory limits on electromagnetic fields.

[0118] Figure 15 illustrates a schematic diagram of a system 1500 that may implement the methods discussed herein. The system comprises an antenna array 1540 comprising a plurality of antenna elements 1542. More or fewer antenna elements 1542 than are illustrated may be present.

[0119] The antenna array 1540 is in communication with a module 1550 configured to dynamically allocate resources (including time, frequency and a transmission power parameter) for the antenna array 1540. The module 1550 may be a scheduler.

[0120] The antenna array 1540 may be comprised within a base station 1530. The base station 1530 may be a 3G, 4G, 5G, 6G base station or beyond. The base station 1530 may specifically be a NodeB, eNodeB or gNodeB, for instance

[0121] It will be appreciated that the transmission power parameter values and limits discussed herein are exemplary and that other transmission power parameter values and limits may be used.

[0122] As used herein, transmitting the signals within a time period may mean that the signals are transmitted simultaneously or effectively simultaneously. It will be understood that transmitting simultaneously need not mean that the signals are sent in the exact sameP264726WOOO P110543-WO (1001009)moment but may instead be sent within a time period sufficiently small that they can be considered simultaneous for telecommunications purposes - for example, in MIMO or Massive MIMO use.

[0123] The methods described herein may be implemented with computer system configurations including hand-held devices, microprocessor systems, microprocessor- based or programmable consumer electronics, minicomputers, mainframe computers and the like. The embodiments can also be practiced in distributed computing environments, where tasks are performed by remote processing devices that are linked through a network.

[0124] Certain embodiments can also be embodied as computer-readable code on a non-transitory computer-readable medium. The computer readable medium is any data storage device than can store data, which can thereafter be read by a computer system. Examples of the computer readable medium include hard drives, network attached storage (NAS), read-only memory, random-access memory, CD-ROMs, CD-Rs, CD-RWs, magnetic tapes, and other optical and non-optical data storage devices. The computer readable medium can also be distributed over a network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. Although embodiments according to the disclosure have been described with reference to particular types of devices and applications (particularly telecommunications and network devices) and the embodiments have particular advantages in such case, as discussed herein, approaches according to the disclosure may be applied to other types of device and / or application. Each feature disclosed in this specification, unless stated otherwise, may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0125] All of the aspects and / or features disclosed in this specification may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. In particular, the preferred features of the disclosure are applicable to all aspects and embodiments of the disclosure and may be used in any combination.Likewise, features described in non-essential combinations may be used separately (not in combination).

[0126] It will be appreciated that there is an implied “about” prior to power values and so on discussed in the present teachings, such that slight and insubstantial deviations are within the scope of the present teachings. Furthermore, values referred to as being “equal” may in fact differ by less than a threshold amount. The threshold amount may be 5%, for example. The threshold may also be greater than 5% (e.g., 10%, 20% or 50%) or less than 5% (for example, 2% or 1 %).

[0127] As used herein, including in the claims, unless the context indicates otherwise, singular forms of the terms herein are to be construed as including the plural form and viceP264726WOOO P110543-WO (1001009)versa. For instance, unless the context indicates otherwise, a singular reference herein including in the claims, such as "a" or "an" (such as a communication channel, for instance) means "one or more" (for instance, one or more communication channels). It will also be appreciated that the terms “one or more” and “at least one” are interchangeable.

[0128] Throughout the description and claims of this disclosure, the words "comprise", "including", "having" and "contain" and variations of the words, for example "comprising" and "comprises" or similar, mean "including but not limited to", and are not intended to (and do not) exclude other components. Also, the use of “or” is inclusive, such that the phrase “A or B” is true when “A” is true, “B is true”, or both “A” and “B” are true.

[0129] The use of any and all examples, or exemplary language ("for instance", "such as", "for example" and like language) provided herein, is intended merely to better illustrate the disclosure and does not indicate a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

[0130] The terms “first” and “second” may be reversed without changing the scope of the invention. That is, an element termed a “first” element (for example, a first signal) may instead be termed a “second” element (for example, a second signal) and an element termed a “second” element (for example, a second signal) may instead be considered a “first” element (for example, a first signal). It will also be appreciated that other labelling may be used without changing the scope of the invention (for example, referring to an element by its function or use, such as, for instance, an MU-MIMO signal).

[0131] Any steps described in this specification may be performed in any order or simultaneously unless stated or the context requires otherwise. Moreover, where a step is described as being performed after a step, this does not preclude intervening steps being performed.

[0132] It is also to be understood that, for any given component or embodiment described herein, any of the possible candidates or alternatives listed for that component may generally be used individually or in combination with one another, unless implicitly or explicitly understood or stated otherwise. It will be understood that any list of such candidates or alternatives is merely illustrative, not limiting, unless implicitly or explicitly understood or stated otherwise.

[0133] In this detailed description of the various embodiments, for the purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the embodiments disclosed. One skilled in the art will appreciate, however, that these various embodiments may be practiced with or without these specific details. Furthermore, one skilled in the art can readily appreciate that the specific sequences in which methods areP264726WOOO P110543-WO (1001009)presented and performed are illustrative and it is contemplated that the sequences can be varied and still remain within the scope of the various embodiments disclosed herein.

[0134] All literature and similar materials cited in this application, including but not limited to patents, patent applications, articles, books, treaties and internet web pages are expressly incorporated by reference in their entirety for any purpose. Unless otherwise described, all technical and scientific terms used herein have a meaning as is commonly understood by one of ordinary skill in the art to which the various embodiments described herein belongs.

Claims

P264726WOOO P110543-WO (1001009)CLAIMS:

1. A method of configuring an antenna configured to transmit a plurality of signals, the method comprising steps of:controlling the antenna to operate using a maximum allowable transmission power parameter for the antenna as a transmission power parameter limit of two or more of the plurality of signals; andconfiguring the antenna to transmit each of the plurality of signals using a respective transmission power parameter that does not exceed the transmission power parameter limit.

2. The method according to claim 1 , wherein a sum of the transmission power parameters is greater than the maximum allowable transmission power parameter for the antenna.

3. The method according to claim 1 or claim 2, wherein at least one of the transmission power parameters is equal to the transmission power parameter limit.

4. The method according to claim 3, wherein each of the transmission power parameters is equal to the transmission power parameter limit.

5. The method according to any previous claim, wherein the configuring comprises determining a transmission power parameter for one or more of the plurality of signals.

6. The method according to claim 5, wherein, when a sum of the transmission power parameter limits for the two or more of the plurality of signals exceeds a usable transmission power parameter of the antenna, the determining comprises determining a transmission power parameter for the one or more of the plurality of signals such that the sum of the determined transmission power parameters does not exceed the usable transmission power parameter of the antenna.

7. The method according to any previous claim, wherein the transmission power parameter corresponds to a power equivalent isotropic radiated power, EIRP, radiation intensity, signal intensity, RF field strength or power density.22P264726WOOO P110543-WO (1001009)8. The method according to any previous claim, wherein the plurality of signals comprises a plurality of antenna beams, layers or patterns in which an antenna radiates or receives electromagnetic energy.

9. The method according to any previous claim, further comprising, prior to the configuring, identifying whether a portion of a first signal is expected to intersect with a portion of a second signal.

10. The method according to claim 9, wherein the identifying comprises determining whether a main lobe of the first signal is expected to intersect a secondary lobe of the second .

11. The method according to claim 9 or claim 10, further comprising, in response to identifying that the portion of the first signal is expected to intersect with the portion of a second antenna signal, determining a first transmission power parameter for the first antenna signal and a second transmission power parameter for the second antenna signal such that the resulting transmission power parameter in the region of intersection does not exceed the transmission power parameter limit.

12. The method according to any previous claim, wherein the antenna comprises a multi-input and multi-output, MIMO, antenna, a Massive MIMO antenna, a beamforming antenna or phase array antenna.

13. The method according to claim 12 when the antenna comprises a MIMO antenna, wherein the antenna is configured to operate as a single user MIMO antenna and / or a multi-user MIMO antenna.

14. The method according to any previous claim, wherein the maximum allowable transmission power parameter for the antenna is defined based on an electromagnetic field level estimation and / or an electromagnetic exposure limit for a human.

15. The method according to any previous claim, further comprising transmitting the plurality of signals with according to the configured transmission power parameters.

16. A system configured to implement the method of any previous claim.P264726WOOO P110543-WO (1001009)17. The system of claim 16, wherein the system comprises a beamforming system.

18. The system according to claim 16 or claim 17, wherein the system comprises an antenna.

19. The system according to claim 18, wherein the antenna comprises a multi-input and multi-output, MIMO, antenna, a Massive MIMO antenna, a beamforming antenna or phase array antenna.

20. A computer program comprising instructions that, when executed by a processor, cause the processor to implement the steps of any one of claims 1 to 16.21 . A computer-readable medium comprising the computer program according to claim 20.

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