Device and method for determining information about a radiated power of a transmission signal

Abstract

Apparatus (100, 200, 300) for determining information about a radiated power of a transmission signal, the apparatus comprising: a first radio frequency generation module (110) configured to generate a first radio frequency transmission signal (112) from a first baseband signal (102); a first coupler module (120) configured to provide a first radio frequency forward feedback signal (122) based on the first radio frequency transmit signal (112) to be transmitted by a first antenna (104) and a first radio frequency reverse feedback signal (124) based on a reflected portion of the first radio frequency transmit signal (112) received by the first antenna (104); a radiated power determination module (140) configured to determine first forward power information based on the first baseband signal (102) and the first radio-frequency forward feedback signal (122) and first reverse power information based on the first baseband signal (102) and the first radio-frequency reverse feedback signal (124), wherein the radiated power determination module (140) is configured to generate a first radiated power information signal (142) comprising information indicative of a radiated power of the first radio-frequency transmit signal (112) based on the first forward power information and the first reverse power information; and a first power amplifier module (360) and a first power control module (350), wherein the first power amplifier module (360) is configured to amplify the first radio frequency transmission signal (112) before the first radio frequency transmission signal (112) is supplied to the first coupler module (120), wherein the first power control module (350) is configured to control a gain of the first power amplifier module (360) based on the first radiated power information signal (142).

Description

Technical FieldThe present disclosure relates to the transmission of signals in wireless communication systems, and more particularly to an apparatus and method for determining information about a radiant power of a transmit signal.BackgroundTransceivers for wireless standards such as wireless local area networks (WLAN) control the transmit power, i.e., the power delivered at the output stage of the radio frequency (RF) transmit path.From a practical point of view, control of the radiation power, i.e. the power delivered to the environment by the transmitter (e.g. a mobile telephone set), is of greater importance, since the radiation power (i.e. not the transmission power) determines, for example, the quality of the wireless connection. Moreover, the national regulatory authorities define the upper limit of the radiation power at a certain distance from the transmitting antenna. It is therefore desirable to estimate the radiation power of a transmitter.US 2013 / 0107914 A1 describes antenna tuning using a ratio between forward and reflected signals. For this purpose, a cross-correlation between a baseband signal and a feed-forward signal or a feed-back signal is calculated and this is used to determine a complex feed-back gain and a complex feed-forward gain. This information is used to drive an antenna tuning module in order to reduce impedance mismatch

[0046] .US 2013 / 0165056 A1 describes a wireless communication device having an adjustable impedance matching network. Here, based on a feedback signal and a baseband transmit signal, the impedance of the impedance matching network is changed to reduce impedance mismatch.The document US 2011 / 0237291 A1 describes a power detection circuit. In this case, an alarm signal is generated on the basis of feedback signals if a predefined limit value is undershot

[0069] .Document WO 2010 / 112364 A1 describes a radio system and a method for forwarding packet-based radio signals.US 2010 / 0093282 A1 describes a multi-transceiver architecture for sophisticated antennas.The document US 2007 / 0026838 A1 describes a power amplifier with VSWR detection and correction function.SummaryThere is a need to provide a concept for determining information on radiation power of a transmission signal.This need may be met by an apparatus according to claim 1, 2, 18 or 20, a transmitter or transceiver according to claim 21, a method according to claim 22 or a computer program according to claim 23.Brief Description of the DrawingsSome examples of devices and / or methods are described below, merely for illustrative purposes, with reference to the accompanying figures, wherein FIG. 1 illustrates a block diagram of an apparatus for determining information about a radiation power of a transmission signal; FIG. 2 illustrates a block diagram of a further apparatus for determining information about a radiation power of a transmission signal; FIG. 3 illustrates a block diagram of a further apparatus for determining information about a radiation power of a transmission signal; FIG. 4 ashows a block diagram of a further device for determining information about a radiation power of a transmission signal; FIG. 4 b illustrates a block diagram of a further apparatus for determining information about a radiation power of a transmission signal; FIG. 5 illustrates a block diagram of a mobile device; FIG. 6 illustrates a flow diagram of a method for determining information about a radiation power of a transmission signal; and FIG. 7 illustrates a flow diagram of a method for determining information about a radiation power of a transmission signal.DETAILED DESCRIPTIONReferring now to the accompanying drawings, in which some illustrative examples are illustrated, various illustrative examples will be described in more detail. In the figures, the thicknesses of lines, layers, and / or regions may be exaggerated for clarity.Accordingly, while the examples are capable of various modifications and alternative forms, the illustrative examples are in the figures and are described in detail herein. It is to be understood, however, that there is no intention to limit the examples to the particular forms disclosed, but on the contrary, the examples are intended to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like reference numerals refer to like or similar elements throughout the description of the figures.It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element or intervening elements may be present. In contrast, there are no intervening elements when an element is referred to as being "directly connected" or "directly coupled" to another element. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "immediately between," "adjacent" versus "immediately adjacent," etc.).The terminology used herein is for describing particular examples only and is not intended to be limiting of the examples. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly suggests otherwise. It will be further understood that the terms "comprises," "comprising," "has," and / or "having," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one / r or more other features, integers, steps, operations, elements, components, and / or groups thereof.Unless otherwise defined, all (technical and scientific) terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these examples belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be construed as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.FIG. 1 illustrates a block diagram of an apparatus 100 for determining information about a radiation power of a transmission signal according to an example. The apparatus 100 may be a mobile communication device such as a mobile phone, tablet, notebook, etc., or a device implemented within a mobile communication device. The apparatus 100 comprises a first radio frequency generation module 110, a first coupler module 120 and a radiation power determination module 140. The first high-frequency generation module 110 generates a first high-frequency transmission signal 112 from a first baseband signal 102. The first coupler module 120 provides a first radio frequency feed-forward signal 122 based on the first radio frequency transmit signal 112 to be transmitted by a first antenna 104 and a first radio frequency feed-back signal 124 based on a reflected portion of the first radio frequency transmit signal 112 received by the first antenna 104. Further, the radiation power determination module 140 determines first forward power information based on the first baseband signal 102 and the first high frequency feed-forward signal 122, and first reverse power information based on the first baseband signal 102 and the first high frequency feed-back signal 124. In addition, the radiation power determination module 140 generates a first radiation power information signal 142 including information indicating radiation power of the first high-frequency transmission signal 112 based on the first forward power information and the first reverse power information.By correlating the baseband signal 102 and a signal proportional to the radio frequency transmit signal to be transmitted, information or magnitude of the power of the radio frequency transmit signal 112 provided to the coupler module 120 may be determined. Accordingly, by correlating the baseband signal 102 with a signal proportional to a reverse wave signal received at the output port of the coupler module 120, information or a magnitude of power of reflected signal portions of the radio frequency transmit signal 112 to be transmitted may be determined. Based on the information about the power of the radio frequency transmit signal supplied to the coupler module 120 and the power of the reflected signal portions, information about the radiation power of the transmitted radio frequency transmit signal 112 may be determined. In this way, information or a magnitude of the power of the transmit signal at a predefined distance from the antenna may be determined more accurately or achieved more accurately, for example. Further, stability of a wireless connection to an external receiver can be improved.For example, the apparatus 100 may include the (first) radio frequency generation module 110, the (first) coupler module 120, a (first) baseband frequency generation module 130, and the radiation power determination module 140. The (first) radio frequency generation module 110 may generate a first radio frequency transmit signal 112 at least by up-mixing the (first) baseband signal 102. The (first) coupler module 120 may include at least one input port 106 coupled to the (first) radio frequency generation module 110, an output port 107 to be coupled to at least the (first) antenna 104, a feed-forward port 108, and a feed-back port 109. Further, the (first) coupler module 120 may provide a (first) radio frequency feed-forward signal 122 at the feed-forward port 108 of the (first) coupler module 120, and may provide a (first) radio frequency feed-back signal 124 at the feed-back port 109 of the (first) coupler module 120.The (first) baseband frequency generation signal 130 may generate a (first) baseband feed-forward signal 132 at least by down-mixing the (first) radio frequency feed-forward signal 122, and may generate a (first) baseband receive feed-forward signal 134 at least by down-mixing the (first) radio frequency feed-back signal 124. The radiation power determination module 140 may determine at least one or a plurality of (first) forward correlation values representing the first forward power information based on the (first) baseband signal 102 and the (first) baseband forward feedback signal 132, and may determine at least one or a plurality of (first) reverse correlation values representing the first reverse power information based on the first baseband signal 102 and the (first) baseband reverse feedback signal 134. Further, the radiation power determination module 140 may generate the (first) radiation power information signal 142 including information indicating radiation power of the (first) radio frequency transmission signal 112 based on the at least one or the plurality of (first) forward correlation values and the at least one or the plurality of (first) reverse correlation values.The first baseband (transmit) signal 102 may include information to be transmitted to an external receiver. The first baseband signal 102 may comprise a frequency bandwidth that is in the baseband range of the apparatus 100 (e.g. below 100 MHz or below 500 MHz).The first radio frequency generation module 110 may perform at least up-mixing (e.g., and optionally amplifying and filtering) the first baseband signal 102 from the baseband domain to a radio frequency domain of the apparatus 100 (e.g., by mixing the baseband signal with an oscillator signal) to generate the first radio frequency transmit signal 112 (e.g., to be transmitted to an external receiver).The first radio frequency transmit signal 112 may include signal portions having one or more frequency bands (e.g., between 500 MHz and 10 GHz). The first radio frequency transmit signal 112 is provided to an input port 106 of the first coupler module 120 and from the output port 107 of the coupler module 120 at least substantially to the first antenna 104 (e.g., a minor portion of the first radio frequency transmit signal is provided to the feed forward port 108 due to the coupling of the feed forward port 108 and the input port 106 of the first coupler module). Thereafter, the first radio frequency transmit signal 112 is substantially transmitted (e.g., over 50% of the power) by the first antenna 104, although a portion of the first radio frequency transmit signal 112 may be reflected, for example, by an antenna mismatch (e.g., varying load of the antenna) and / or one or more reflections of signal portions from objects proximate to the device 100 (echoes).The first coupler module 120 (e.g., implemented by a 4-port directional coupler or two 3-port directional couplers) may include an input port 106, an output port 107, a feed-forward port 108, and a feed-back port 109. The input terminal 106 is coupled to the first radio frequency generation module 110, for example, by an electrical connection or by one or more other electrical elements (e.g., power amplifiers and / or filters). Further, the output port 107 is configured to be coupled to the first antenna 104 (e.g., the antenna may be an internal element or an external element connected to the device), for example, by an electrical connection or by one or more other electrical elements (e.g., antenna switches and / or filters). A signal obtained at the feed-forward terminal 108 is substantially (e.g., greater than 70%, greater than 90%, or greater than 99%) caused by a signal supplied to the input terminal 106, and a signal obtained by the feed-back terminal 109 is substantially (e.g., greater than 70%, greater than 90%, or greater than 99%) caused by a signal received at the feed-back terminal 109. In other words, the first radio frequency feed-forward signal 122 provided at the feed-forward terminal 108 is substantially caused by the first radio frequency transmit signal 112 received at the input terminal 106, and the first radio frequency feed-back signal 124 is substantially caused by a reverse wave signal (e.g., caused by antenna mismatch or reflection at an object near the device) received at the output terminal 107.The first radio frequency feed-forward signal 122 is derived from the first radio frequency transmit signal 112. For example, the first radio frequency feed-forward signal 122 may be a portion of the first radio frequency transmit signal 112 itself, or the first radio frequency transmit signal 112 may cause the first radio frequency feed-forward signal 122 by capacitive or inductive coupling of the transmit path to a coupling element (e.g., directional coupler or transformer disposed proximate the transmit path) of the first coupler module 120. For example, the apparatus 100 may include a directional coupler constituting the first coupler module 120 and disposed in the transmission path (e.g., after amplification of the first radio frequency transmission signal). A directional coupler may derive the first radio frequency feed-forward signal 122 (at the feed-forward terminal) from the first radio frequency signal 112 (applied to the input terminal).The percentages of signal parts may vary over a wide range. For example, the transmit signal P_TX (e.g., power of the radio frequency transmit signal) at the TX output (e.g., transmit path output) P_TX may be between 0.1 and 2 watts (P_TX may define the 100%). A power portion of the forward signal at the first coupler output port may be, for example, P_FC_ 1 between 1% (e.g., under normal conditions) and 20%. A power portion of the reverse signal at the first coupler output terminal may be P_RC_ 1 between 0.01 % (e.g., under normal conditions) and 20 % (e.g., in the case of a partial antenna break, antenna shorted to metal surface, etc.). Further, a power portion of the reverse signal at the second coupler output port may be, for example, P_RC_ 2 between 1% (e.g., in the case of good antenna isolation) and 25% (e.g., in the case of poor antenna isolation).Similarly, the first high frequency feedback signal 124 may be derived from the first high frequency transmit signal 112. The first radio frequency feedback signal 124 is generated based on a reflected portion of the first radio frequency transmit signal 112 received by the first antenna 104. In other words, the first radio frequency feedback signal 124 may be substantially caused by a reverse wave signal (e.g., caused by antenna mismatch or by reflection at an object near the device) received at a port connected to the first antenna 104. The first antenna 104 may be an external device connected to the device 100, or may be a part of the device. For example, the first high frequency feedback signal 124 may be a portion of the reverse wave received at an output port 107 of the first coupler module 120 itself, or the reverse wave signal received at the output port 107 may cause the first high frequency feedback signal 124 by capacitive or inductive coupling of the reverse transmission path to a coupling element of the first coupler module 120 (e.g., directional coupler or transformer located proximate to the transmission path).The first high frequency feed-forward signal 122 and the first high frequency feed-back signal 124 are in the high frequency range of the device 100. The first radio frequency feed-forward signal 122 and the first radio frequency feed-back signal 124 may be down mixed (e.g., mixed down to baseband) by the first baseband frequency generation module 130 to generate (substantially mixed down to baseband) a first baseband feed-forward signal 132 and a first baseband feed-back signal 134. The first baseband feed-forward signal 132 and the first baseband feed-back signal 134 may comprise a frequency bandwidth that is in the baseband range of the apparatus 100.The first baseband frequency generation module 130 may generate the first radio frequency feed-forward signal 122 and the first radio frequency feed-back signal 124 simultaneously or during successive time intervals (e.g., comprising a predefined length between 50 and 5000 symbol intervals). In other words, the first baseband frequency generation module 130 may include a feedback receiver module that generates the first baseband feedforward signal 132 during a first time interval and the first baseband feedback signal 134 during a second, subsequent time interval. For example, the first baseband frequency generation module 130 may optionally include a multiplexer or a plurality of switching elements that supply the first radio frequency feed-forward signal 122 to an input of the feedback receiver module (e.g., FIG. 3 ) during the first time interval and the first radio frequency feed-back signal 124 to the input of the feedback receiver module during the second time interval. Alternatively, for example, the first baseband frequency generation module 130 may include a first feedback receiver module (e.g., FIG. 3 ) that generates the first baseband feedforward signal 132 and a second feedback receiver module that simultaneously generates the first baseband feedback signal 134.The first radiation power information signal 142 includes information indicative of radiation power (or energy) of the first radio frequency transmit signal 112. Such information can be presented in various ways. For example, a magnitude or magnitude of reflected signal portions may be included in the first radio frequency transmit signal 112 such that the radiant power of the first radio frequency transmit signal 112 may be inferable or may be determined by comparing this information to a magnitude or magnitude of the power of the first radio frequency transmit signal 112 supplied to the first coupler module 120. Alternatively, the information may indicate a magnitude or magnitude of the radiant power of the first radio frequency transmit signal 112 itself. The radiation power determination module 140 may include information indicating the radiation power of the first radio frequency transmit signal 112 repeatedly (e.g., at random or constant time intervals). For example, the information about the radiation power of the first radio frequency transmit signal 112 may be repeatedly determined after a time between one second and ten seconds, e.g. each second, every five seconds or every ten seconds (e.g. for WLAN), for example. The radiation power (or energy) may be a power (or energy) of a portion of the transmit signal that is not reflected within the transmit path or not received (e.g., due to reflections) by the antenna (e.g., by one of the antennas) of the device 100.The first radiant power information signal 142 may be determined based on correlation values. The radiation power determination module 140 may determine at least one or a plurality of correlation values. The correlation values determined by the radiant power determination module 140 may be determined in various ways.A correlation value may indicate, for example, a correlation magnitude or correlation strength of at least two signals for a predefined time delay between the at least two signals. The time delay may be changed for determining the at least one or the plurality of correlation values.For example, the at least one or a plurality of first forward correlation values may represent cross-correlation coefficients of a cross-correlation of the first baseband signal 102 and the first baseband forward feedback signal 132. The cross-correlation may be a measure of the similarity of the two signals as a function of a time shift applied to one of them, such that the cross-correlation may be proportional to the power of the first radio frequency transmit signal 112.Accordingly, the at least one or the plurality of first backward correlation values may be cross-correlation coefficients of a cross-correlation of the first baseband signal 102 and a first high frequency backward feedback signal 134, such that the cross-correlation may be proportional to a power of backward wave signals received at the output terminal of the first coupler module 120.In other words, the radiation power determination module 140 may determine the at least one or the plurality of first forward correlation values based on a cross-correlation function of the first baseband signal 102 and the first baseband forward feedback signal 132 and the at least one or the plurality of first backward correlation values based on a cross-correlation function of the first baseband signal 102 and the first baseband backward feedback signal 134.For example, the radiant power determination module 140 may determine the at least one or the plurality of first forward correlation values at least by determining at least one or a plurality of expected values based on the first baseband signal 102 and the first baseband forward feedback signal 132 and the at least one or the plurality of first reverse correlation values at least by determining at least one or a plurality of expected values based on the first baseband signal 102 and the first baseband reverse feedback signal 134. In other words, a correlation value may be determined by calculating an expected value of a first signal and a delayed second signal with a predefined time delay.For example, an expected value may be calculated by: where E[m] is the expected value for a predefined time delay m, s 1[ i] is a signal amplitude of the first signal at time i, and s 2[ i+m] is an amplitude of the second signal at time i plus the time delay m.The product of the amplitude values of the two signals may be summed over 50 to 5000 symbol intervals (or 100 to 1000), for example. Both signals can be digital signals, so that discrete amplitude values can already be present. A symbol interval may be an arbitrary number of discrete amplitude values of the signal (e.g., depending on a length of the symbol interval and / or an operating frequency of the radiant power determination module). The symbol interval may be, for example, a time interval reserved for the transmission of a complex symbol (symbol constellation) representing a sequence of binary information.The plurality of first forward correlation values may be determined, for example, by: where h FCV[ m] indicates the plurality of first forward correlation values determined for a plurality of defined time delays m, s 102[ i] indicates amplitude values of the first baseband signal at time i, and s 132[ i+m] indicates amplitude values of the first baseband feedforward signal at time i plus the time delay m.The predefined time delays m may be selected, for example, between a time delay caused by a delay time through the upmix module 110, the coupler module 120 and the downmix module 130 and the maximum time delay taken into account for the occurrence of reflected signal portions.The plurality of first backward correlation values may be determined, for example, by: where h RCV[ m] indicates the plurality of first backward correlation values determined for a plurality of defined time delays m, si 102[ i] indicates amplitude values of the first baseband signal at time i, and s 134[ i+m] indicates amplitude values of the first baseband backward feedback signal at time i plus the time delay m. The backward correlation values can also be called echo coefficients, for example.Correlation values associated with a predefined time delay corresponding to a reflected signal portion (e.g., at the antenna due to an antenna mismatch or an echo reflected by an object near the device) include values other than zero or not negligible. In contrast, correlation values with predefined time delays without correlation to a reflected signal portion are zero or comprise negligible values, for example.A larger index value m corresponds to an echo reflected by an object with a larger distance from the device. A smaller index value m corresponds to an echo reflected by an object with a smaller distance from the device.Based on the first forward correlation values, an indication of the power of the first radio frequency transmit signal 112 supplied to the input port of the first coupler module 120 may be determined. For example, the correlation value corresponding to the predefined time delay caused by the delay difference of the first baseband signal 102 and the first baseband feed-forward signal 132 to the radiation power determination module 140 is proportional to a power of the first radio frequency transmit signal 112.For example, the information about the power of the first high-frequency transmission signal 112 and a power of reflected signal portions of the first high-frequency transmission signal 112 may be determined by using an accumulation function. For example, an accumulation value may be determined by an accumulation function as: or wherein A V indicates an accumulation value, h[m] indicates correlation values at predefined time delays m, 1 indicates a predefined minimum time delay, and k indicates a predefined maximum time delay.In other words, the radiation power determination module 140 may generate the first radiation power information signal 142 based on, for example, a first forward correlation accumulation value A FCV, which is determined based on an accumulation function of the at least one or the plurality of first forward correlation values, and a first backward correlation accumulation value A RCV which is determined based on an accumulation function of the at least one or the plurality of first backward correlation values.Optionally, the radiant power determination module 140 may generate the first radiant power information signal 142 based on a subtraction of the first backward correlation accumulation value from the first forward correlation accumulation value. In other words, the value indicating power of reflected signal portions received at the output terminal of the first coupler module 120 may be subtracted from the value indicating the power of the first high frequency transmission signal 112 supplied to the input terminal of the coupler module 120, for example.Optionally, the value of the index k of the first backward accumulation function determines the distance between the device and the reference point for which the radiation power estimation is performed.For example, correlation values may optionally, additionally or alternatively be determined based on a least mean square (LMS) algorithm.Optionally, a relationship between the accumulation function Av and the absolute value of the transmitted or reflected power may be determined by measurement.The apparatus 100 may include, for example, one or more optional additional signal processing elements (e.g., filter elements, amplifier elements, switching elements, duplex and / or multiplex elements).The first radio frequency generation module 110, a first coupler module 120, a first baseband frequency generation module 130, and a radiation power determination module 140 may be independent hardware units or part of a processor, a microcontroller, or a digital signal processor, or the functionality may be implemented, for example, by a computer program or software product for execution on a processor, a microcontroller, or a digital signal processor. Further, the first radio frequency generation module 110, a first coupler module 120, a first baseband frequency generation module 130, and a radiation power determination module 140 may be implemented independently of each other or at least partially together (e.g., on a common semiconductor chip and / or sharing one or more common electrical elements).In some examples, the device 100 includes more than one transmit path and more than one antenna. In this case, a portion of a signal transmitted by an antenna may be absorbed by or reflected to the at least one further antenna, thereby reducing power radiated to external receivers. The power of the signal absorbed by or reflected to other antennas of the device may be taken into account for the determination of the information about the radiation power.FIG. 2 illustrates a block diagram of an apparatus 200 for determining information about a radiation power of a transmission signal according to an example. The implementation of the device 200 is similar to the device illustrated in FIG. 1. However, the apparatus 200 includes a second transmission path including at least a second radio frequency generation module 260, a second coupler module 270, a second antenna 254, and a second feedback receiver module 282. The second radio frequency generation module 260 generates a second radio frequency transmit signal 262 at least by up-mixing a second baseband signal 252, and the at least second antenna 254 transmits at least a portion (e.g., reduced by reflections due to antenna mismatch) of the second radio frequency transmit signal 262. The radiation power determination module 240 determines at least one or a plurality of first antenna coupling correlation values representing the first antenna coupling power information based on the second baseband signal 252 and the first baseband feedback signal 134. Further, the radiation power determination module 240 generates a second radiation power information signal comprising information indicative of a radiation power of the second radio frequency transmit signal 252 based on the at least one or the plurality of first antenna coupling correlation values. In other words, a correlation of the second baseband signal 252 and the first baseband reverse feedback signal 134 may be determined by indicating signal portions received by the first antenna 104 due to, for example, direct transmission from the second antenna 254 or reflections at objects proximate the device 200.By using the feedback path of the first transmission path, information on reflected signal parts caused by signals transmitted through the second transmission path can be obtained. Based on this information, information about the magnitude or magnitude of the transmission power of the signals transmitted through the second transmission path may be determined. In this way, the accuracy of the determination of the radiation power through a transmission path can be significantly improved.The functionality and / or implementation of the second radio frequency generation module 260 may be similar to the functionality and / or implementation of the first radio frequency generation module 110 described above, the characteristics of the second radio frequency transmit signal 262 may be similar to the characteristics of the first radio frequency transmit signal 112, and the characteristics of the second baseband (transmit) signal 252 may be similar to the first baseband signal 102 described above. Further, the at least one or the plurality of first antenna coupling correlation values may be determined similar to or corresponding to the first forward correlation values and the first backward correlation values, as described above. In other words, several details and aspects regarding the various modules and signals are described above (e.g., in connection with FIG. 1 ) accordingly.Optionally, the apparatus 200 includes a second coupler module and a second baseband frequency generation module (e.g., represented by a second feedback receiver module, a first switching element, and a second switching element), as shown in FIG. 2. The second coupler module 270 (implemented by a 4-port directional coupler) includes a first input port 1 coupled or connected to the second radio frequency generation module 260, an output port 2 to be coupled or connected to the second antenna 254, a feed-forward port 3, and a feed-back port 4. the second coupler module 270 provides a second radio frequency feed-back signal 272 at the feed-forward port 3 of the second coupler module 270 and provides a second radio frequency feed-back signal 274 at the feed-back port 4 of the second coupler module 270. The second high frequency feed-forward signal 272 is substantially caused by the second high frequency transmit signal 262 received at the input terminal 1 of the second coupler module 270, and the second high frequency feed-back signal 274 is substantially caused by a reverse wave signal received at the output terminal 4 of the second coupler module 270.The second baseband frequency generation signal generates a second baseband feed-forward signal 232 at least by down-mixing the second radio frequency feed-forward signal 272 and a second baseband feed-back signal 234 at least by down-mixing the second radio frequency feed-back signal 274.The functionality and / or implementation of the second coupler module 270 is similar to the first coupler module as described above, and the functionality and / or implementation of the second baseband frequency generation module is similar to the functionality and / or implementation of the first baseband frequency generation module described above. Further, the characteristics of the second radio frequency feed-forward signal 272, the second radio frequency feed-back signal 274, the second baseband feed-forward signal 232, and the second baseband feed-back signal 234 are similar to the characteristics of the first radio frequency feed-forward signal, the first radio frequency feed-back signal, the first baseband feed-forward signal, and the first baseband feed-back signal described above. Accordingly, several details and aspects are described above (e.g., in connection with FIG. 1 ).The radiation power determination module 140 may determine at least one or a plurality of second forward correlation values representing second forward power information based on the second baseband signal 252 and the second baseband feedforward signal 232, and determines at least one or a plurality of second backward correlation values representing second backward power information based on the second baseband signal 252 and the second baseband feedback signal 234. Further, the radiation power determination module 140 may generate the second radiation power information signal comprising information indicating radiation power of the second radio frequency transmission signal based on the at least one or the plurality of second forward correlation values, the at least one or the plurality of second backward correlation values, and the at least one or the plurality of first antenna coupling correlation values.The radiation power determination module 140 may determine the at least one or the plurality of second forward correlation values and the at least one or the plurality of second backward correlation values according to any of the examples described above (e.g. using a cross correlation function and / or expected values).Alternatively, a second transmission path for improving the accuracy of determination of radiation power information of the first high-frequency transmission signal 112 may not be necessary. A second feedback path may be sufficient. The second coupler module could omit the feedforward port. In other words, the apparatus 100 may further comprise a second baseband generation module to be coupled to a second antenna (the antenna may be, e.g., an internal element or an external element connected to the apparatus) and configured to generate a second baseband feedback signal at least by down-mixing a second radio frequency feedback signal.Further, optionally, the radiation power determination module 140 determines (in both cases, with or without a second transmission path) at least one or a plurality of first antenna coupling correlation values representing second antenna coupling power information based on the first baseband signal 102 and the second baseband feedback signal 234. Further, the radiation power determination module 140 may generate the first radiation power information signal 142 including information indicating radiation power of the first radio frequency transmission signal 112 based on the at least one or the plurality of first forward correlation values, the at least one or the plurality of first backward correlation values, and the at least one or the plurality of second antenna coupling correlation values. In other words, similar to taking into account the part of the signal transmitted by the second transmission path that is reflected to the first transmission path, the part of the signal transmitted by the first transmission path that is reflected to the second transmission path can be taken into account for the determination of the information about the radiation power of the first radio-frequency transmission signal 112.In the example illustrated in FIG. 2, the first coupler module 220 and the second coupler module 270 are each implemented by a 4-port directional coupler. Further, the first baseband frequency generation module is implemented by a first feedback receiver module 232 (e.g., that downconverts signals from the radio frequency range to the baseband range), a first switching element a 234 that switches the first radio frequency feed-forward signal 122 to an input of the first feedback receiver module 232 during a first time interval, and a second switching element b 236 that switches the first radio frequency feed-back signal 124 to an input of the first feedback receiver module 232 during a second time interval. Thus, the first feedback receiver module 232 provides the first baseband feed-forward signal 132 to the radiation power determination module 240 during the first time interval, and provides the first baseband feed-back signal 134 to the radiation power determination module 240 during the second time interval.Similarly, the second baseband frequency generation module includes a second feedback receiver module 282, a first switching element a 284 and a second switching element b 286. Thus, the second feedback receiver module 282 provides the second baseband feed-forward signal 232 to the radiation power determination module 240 during the first time interval, and provides the second baseband feed-back signal 234 to the radiation power determination module 240 during the second time interval.Further, the radiant power determination module 140 includes a first correlator module 242 and a second correlator module 244. The first correlator module 242 receives the first baseband signal 102 that can be switched by a first switching element a 203 of the radiation power determination module 240, the second baseband signal 252 that can be switched by a second switching element b 205 of the radiation power determination module 240, the first baseband feed-forward signal 132, and the first baseband feed-back signal 134, and provides the at least one or the plurality of first feed-forward correlation values, the at least one or the plurality of first feed-back correlation values, and the at least one or the plurality of first antenna feed-back correlation values. Similarly, the second correlator module 244 receives the first baseband signal 102 that can be switched by a third switch a 207 of the radiation power determination module, the second baseband signal 252 that can be switched by a fourth switching element b 209 of the radiation power determination module 140, the second baseband feed-forward signal 232 and the second baseband feed-back signal 234, and provides the at least one or the plurality of second feed-forward correlation values, the at least one or the plurality of second feed-back correlation values and the at least one or the plurality of second antenna feed-back correlation values.Further, the radiant power determination module 140 includes a radiant power calculation module (not shown in FIG. 2 ) that generates the first radiant power information signal and the second radiant power information signal based on the correlation values provided by the first correlator module 242 and the second correlator module 244, as previously described (e.g., in connection with FIG. 1 ).The signal 292 transmitted through the first transmission path may be at least partially reflected by an object 290 and may be received by the second antenna 254, and signals 294 transmitted through the second transmission path may also be at least partially reflected by the object 290 and may be received by the first antenna 104, as shown in FIG. 2.The proposed concept can also be used for more than two transmission paths or antennas. In this case, each antenna may receive reflected signal portions, or it may directly receive signal portions from each of the other antennas. The signal portions from the different antennas may be automatically separated, for example, due to the use of a cross-correlation with the corresponding transmit signal.For example, the example shown in FIG. 2 illustrates a wireless system having two transceivers, two 4-port couplers, and two antennas. To determine information about a radiation power, first switches a may be closed (and switches b are opened) so that the correlator output of the first correlator module and the second correlator module gives information about transmitted output power from ports 1 / 2 (i.e., the first transmission path and the second transmission path) during a first time interval. Then, the switches b of the downmix modules are closed and the switches a of the radiation power determination module are closed so that the correlator outputs of the first correlator module and the second correlator module give information about a reflected signal part of the own antenna (the antenna used for transmitting the baseband signal provided to the switches a of the correlator modules) during a second time interval. In other words, for example, the information about the reflection of the own antenna can also be taken into account for the determination of the radiated signal energy. Thereafter, all switches b are closed (switches a are opened) so that the correlator outputs of the first correlator module and the second correlator module provide information about reflected signal energy from ports 2 / 1 (i.e., the other transmission path) during a third time interval. Then, the term transmitted signal energy from port 1 / 2 - reflected signal energy from port 1 / 2 can be determined. This term is, for example, a measure of the signal radiation energy of terminal 1 / 2.In other words, FIG. 2 illustrates a block diagram of a wireless system that includes, for example, two RF transceivers (only the transmit path and the feedback path of each transceiver are shown), two 4-port couplers, and two antennas.The feedback path may be connected to either the forward or the reverse port of the 4-port coupler.The transmit power may be measured when the input of the feedback path is connected to the forward port of the 4-port coupler, and the output of the feedback path may be correlated with the transmit signal of its own RF transceiver. In this context, the reflected power may include, for example, both the power reflected from external objects and the power received via direct antenna coupling.As already mentioned, the correlation values can be determined in various ways. In addition to the correlation values already mentioned above, the radiation power determination module 240 may generate the first radiation power information signal 142 based on the first forward correlation accumulation value based on the accumulation function of the at least one or the plurality of first forward correlation values, the first backward correlation accumulation value based on the accumulation function of the at least one or the plurality of backward correlation values, and a second antenna coupling correlation accumulation value determined based on an accumulation function (e.g., as mentioned above) of the at least one or the plurality of second antenna coupling correlation values.Further, the radiation power determination module 130 may generate the first radiation power information signal 142 based on a subtraction of the first backward correlation accumulation value A RCV and the first antenna coupling correlation accumulation value A ACCV from the first forward correlation accumulation value A FCV. In other words, the information about the radiation power P r can be determined by:The first radiant power information signal 142 (as well as a second radiant power information signal) may be used in various ways. For example, the first radiation power information signal 142 may be used to control a power gain of the first radio frequency transmit signal 112.FIG. 3 illustrates a block diagram of an apparatus 300 for determining information about a radiation power of a transmit signal according to an example. The implementation of the device 300 is similar to the device illustrated in FIGS. 1 and 2. However, the device 300 includes a power amplifier module 360 and a power control module 350. The power amplifier module 360 is disposed within the transmit path between the upmix module 110 and the coupler module 120. Further, the power control module 350 receives the radiation power information signal 142 from the radiation power determination module 140 and controls the gain of the power amplifier module 360 by a power control signal 352 generated based on the radiation power information signal 142.In other words, the first power amplifier module 360 amplifies the first radio frequency transmit signal 112 before the first radio frequency transmit signal 112 is supplied to the transmit terminal of the first coupler module 120. Further, the first power control module 350 controls the gain of the first power amplifier module 360 based on the first radiation power information signal 142. For example, the power control module 350 may increase the gain of the first power amplifier module 360 when the information about the radiated power of the first radio frequency transmit signal 112 indicates, for example, a decrease in radiated power or an increase in reflected power, and vice versa. Similarly, the power control module may control a power gain of the second high frequency transmission signal in the example illustrated in FIG. 2.By controlling the power of the transmit signal according to a particular radiation power, the power of a signal provided to an external receiver may be more accurately controlled (e.g., kept constant or nearly constant under varying reflection scenarios) at the position of the external receiver. Further, if the radiation power can be controlled by the transmitter or transceiver itself, the overhead at an external receiver can be avoided or reduced by providing information about the radiation power (e.g., at the base station of a wireless communication system). In addition, for example, the adjustment of the radiation power can be performed more quickly than by feedback from an external device.Further details and aspects are described above in connection with FIGS. 1 and 2.Optionally, in addition to or as an alternative to one or more of the aforementioned aspects, the downmix module 130 may also be used for downmixing signals received from an external transmitter and containing data to be used by a device using the apparatus for determining information about the radiant power of the transmit signal. In other words, the first baseband frequency generation module 130 may further generate a baseband reception signal based on down-conversion of a radio frequency reception signal received from an external transmitter.In this way, only one downmix module or receiver module may be necessary for determining the information about the radiation power and for receiving data from external transmitters (e.g. in time division multiple access or TDD systems).Further, optionally, additionally or alternatively to one or more of the aforementioned aspects, the first radio frequency generation module 110, the first coupler module 120, and the first baseband frequency generation module 130 may be implemented on the same semiconductor chip. In this way, a device for determining information about a radiation power of a transmission signal can be provided with little effort.Some embodiments relate to an apparatus for determining information about a radiation power of a transmit signal, comprising first upconversion means configured to generate a first radio frequency transmit signal at least by upconversion of a first baseband signal, and first coupling means comprising at least one input terminal coupled to the upconversion means, an output terminal to be coupled to at least one first antenna, a feed-forward terminal, and a feed-back terminal. The first means for coupling is configured to provide a first high frequency feed-forward signal at the feed-forward terminal and a first high frequency feed-back signal at the feed-back terminal. Further, the apparatus comprises first downmix means configured to generate a first baseband feedforward signal at least by downmix of the first radio frequency feedforward signal and a first baseband feedback signal at least by downmix of the first radio frequency feedback signal. The apparatus also comprises means for determining radiant power information configured to determine at least one or a plurality of first forward correlation values based on the first baseband signal and the first baseband forward feedback signal and at least one or a plurality of first backward correlation values based on the first baseband signal and the first baseband backward feedback signal. Further, the means for determining radiant power information is configured to generate a first radiant power information signal comprising information indicative of a radiant power of the first radio frequency transmit signal based on the at least one or the plurality of first forward correlation values and the at least one or the plurality of first backward correlation values.Further, the apparatus may comprise one or more optional additional features corresponding to one or more aspects mentioned in connection with the described concept or one or more of the examples described above (e.g. FIGS. 1 to 3 ).FIG. 4 ashows a block diagram of an apparatus 490 for determining information about a radiation power of a transmission signal according to an example. The apparatus 490 comprises a first radio frequency generation module 410 (a first signal path), a second baseband frequency generation module 492 (a second signal path) and a radiation power determination module 440. The first radio frequency generation module 410 is configured to generate a first radio frequency transmit signal 412 to be transmitted by a first (internal or external) antenna 404 from a first baseband signal 402. Further, the second baseband frequency generation module 492 may be coupled to a second (internal or external) antenna and configured to generate a second baseband feedback signal 496 from a second radio frequency feedback signal 494 caused by the first radio frequency transmit signal 412. The radiant power determination module 440 is configured to generate a first radiant power information signal 444 comprising information indicative of a radiant power of the first radio frequency transmit signal 412 based on the first baseband signal 402 and the second baseband feedback signal 496.By correlating a signal transmitted through a transmission path and an antenna with a signal received through another antenna of the device 490, information about the magnitude or magnitude of the reflected power (power that is not radiated or can be supplied to an external receiver) can be obtained with high accuracy. Further, if the radiation power can be controlled by the transmitter or transceiver itself, the overhead at an external receiver can be avoided or reduced by providing information about the radiation power (e.g., at the base station of a wireless communication system). In addition, for example, the adjustment of the radiation power can be performed more quickly than by feedback from an external device.Further details regarding the functionality and / or implementation of a radio frequency generation module, a baseband frequency generation module or a radiation power determination module and the signals provided or received by these modules have been explained in connection with the described concept or one or more of the examples described above (e.g. FIGS. 1 to 3 ).FIG. 4 b illustrates a block diagram of an apparatus 400 for determining information about a radiation power of a transmission signal according to an example. The apparatus 400 comprises a first radio frequency generation module 410, a second radio frequency generation module 460, a first coupler module 420, a first antenna 404, a second antenna 454, a first baseband frequency generation module 430, and a radiation power determination module 440. The first radio frequency generation module 410 generates a first radio frequency transmit signal 412 from a first baseband signal 402, and the second radio frequency generation module 460 generates a second radio frequency transmit signal 462 from a second baseband signal 452. Further, the first coupler module 420 includes at least one input terminal coupled to the first radio frequency generation module 410, an output terminal to be coupled to the first antenna 404, and a feedback terminal. The first coupler module 420 provides a first radio frequency feedback signal 424 at the feedback port of the first coupler module 420. In addition, the at least second antenna 454 transmits at least a portion of the second radio frequency transmit signal 462. Further, the first baseband frequency generation module 430 generates a first baseband feedback signal 434 from the first radio frequency feedback signal 424. Further, the radiant power determination module 440 generates a second radiant power information signal 444 (of the second transmission path) comprising information indicative of a radiant power of the second radio frequency transmission signal 462 based on the second baseband signal 402 and the second baseband feedback signal 434.By correlating a signal transmitted through a transmission path and an antenna with a signal received through another antenna of the device 400, information about the magnitude or magnitude of the reflected power (power that is not radiated to or can be supplied to an external receiver) can be obtained with high accuracy. Further, if the radiation power can be controlled by the transmitter or transceiver itself, the overhead at an external receiver can be avoided or reduced by providing information about the radiation power (e.g., at the base station of a wireless communication system). In addition, for example, the adjustment of the radiation power can be performed more quickly than by feedback from an external device.Further details regarding the functionality and / or implementation of a radio frequency generation module, a coupler module, a baseband frequency generation module, or a radiation power determination module and the signals provided or received by these modules have been discussed in connection with the described concept or one or more of the examples described above (e.g. FIGS. 1 to 3 ).For example, the radiation power determination module 440 may determine at least one or a plurality of first antenna coupling correlation values based on the second baseband signal 452 and the first baseband feedback signal 434. Further, the radiation power determination module 440 may generate the second radiation power information signal 444 comprising information indicative of a radiation power of the second radio frequency transmit signal 462 based on the at least one or the plurality of first antenna coupling correlation values.Further, the apparatus 400 may include one or more optional additional features corresponding to one or more aspects mentioned in connection with the described concept or one or more of the examples described above (e.g. FIGS. 1 to 3 ).For example, the apparatus 400 may further include a second coupler module and a second baseband frequency generation module. The second coupler module may include at least one input port coupled to the second radio frequency generation module 460, an output port to be coupled to the second antenna 454, a feed-forward port, and a feed-back port. Further, the second coupler module may provide a second radio frequency feed-forward signal at the feed-forward port of the second coupler module and may provide a second radio frequency feed-back signal at the feed-back port of the second coupler module. The second baseband frequency generation module may generate a second baseband feed-forward signal by at least a down-conversion of the second radio frequency feed-forward signal, and may generate a second baseband feed-back signal by at least a down-conversion of the second radio frequency feed-back signal.The radiation power determination module may determine at least one or a plurality of second forward correlation values based on the second baseband signal and the second baseband feedforward signal, and determines at least one or a plurality of second backward correlation values based on the second baseband signal and the second baseband feedback signal. Further, the radiation power determination module may generate the second radiation power information signal comprising information indicative of a radiation power of the second radio frequency transmission signal based on the at least one or the plurality of second forward correlation values, the at least one or the plurality of second backward correlation values, and the at least one or the plurality of first antenna coupling correlation values.Optionally, a first radiant power information signal comprising information indicative of a radiant power of the first radio frequency transmit signal 412 may be similarly determined.Some examples relate to radiation power estimation in a wireless system with multiple antennas. The proposed concept may be provided, for example, by future cellular transceivers for WIMAX (worldwide interoperability for microwave access for engl. Worldwide interoperability for microwave access) or with WIFI MIMO (multiple input / multiple output for engl. Multiple-input multiple-output) can be used. The described concept provides an approach to estimating the radiant power of a multiple antenna wireless system. This may be of interest for wireless MIMO systems such as LTE, WIMAX, and WIFI.Further, future wireless standards may include measurement and control of radiant power so that the proposed concept may be implemented for future wireless standards, for example.Knowing the transmitted power and reflected power may allow estimation of the radiant power.For example, in the event of a partial antenna break, the radiation power decreases, but this may be indicated by an increase in reflected power measured at the reverse / forward port of its own transmit path. For example, the radiant power decreases in the event of strong external reflections, but this may be indicated by an increase in reflected power measured at the back / forth port of the other transmit or receive path.Knowing the radiation power allows control of the radiation power, i.e. the RF transceiver can adjust the transmit power to obtain the desired radio power. The radiation power can be controlled, for example, without interaction with the base station.Other solutions control only the transmitted output power, for example. Indeed, the quality of the wireless connection can be determined by the radiation power, not by the quality of the transmission power. The radiation power can be controlled locally, i.e. without interaction with the base station. For example, the radiation power can be controlled quite quickly, again without interaction with the base station.An apparatus according to the described concept or one or more of the aforementioned examples may be capable of keeping the radiation power constant or almost constant for different reflection scenarios. In other words, the transmission power may be changed for different reflection scenarios, for example.In a multi-antenna system, each antenna may be used to transmit on its own transmit path and, for example, measure received power from the other transmit path similarly or simultaneously. Knowledge of the own transmitted power and the received / reflected power from the other transceivers may be used to estimate either the radiation power of the own transmission path or the entire system. For example, internal signal processing techniques (as described above) may be used to measure / estimate its own transmitted and received / reflected power.For example, the combination of hardware, software, signal processing and control loop techniques may allow for control and estimation of radiant power. The radiation power may determine the quality of the wireless connection.The proposed concept may be implemented by cellular telephone transceivers and / or platforms. The proposed concept can improve the connection quality of a mobile telephone system. In implementing the proposed concept, user experience may be improved.Some examples relate to a transmitter or a transceiver comprising an apparatus for determining information about a radiation power of a transmission signal according to the proposed concept or one or more of the examples described above.Further examples relate to a mobile device (e.g. a cellular phone, a tablet or a laptop) comprising a transmitter or a transceiver as described above. The mobile device or mobile terminal may be used to communicate with a mobile communication system.FIG. 5 shows a schematic illustration of a mobile device 150. The mobile device comprises a device 100, 200, 300, 400 (e.g. FIGS. 1 to 4 ) for determining information about a power change of a transmission signal. For example, the apparatus comprises at least a (first) radio frequency generation module 110, a (first) coupler module 120, a (first) baseband frequency generation module 130, and a radiation power determination module 140, as described in connection with FIG. 1. Further, the mobile device comprises a baseband processor module 170 that generates at least the (first) baseband (transmit) signal used to generate the (first) radio frequency transmit signal. In addition, the mobile device includes a power supply unit 180 that supplies power to at least the device 100, 200, 300, 400 and the baseband processor module 170.For example, the mobile device 150 may provide information on a power change of a transmission signal to be transmitted with high accuracy.In some examples, a cellular telephone may comprise a transmitter or a transceiver comprising an apparatus for determining information about a power change of a transmit signal according to the proposed concept or one or more of the examples described above.Further, some examples relate to a base station or a relay station of a mobile communication system comprising a transmitter or a transceiver with an apparatus for determining information about a power change of a transmission signal according to the described concept or one or more of the previously described examples.A mobile communication system may correspond to one of the mobile communication systems standardized by the 3rdgeneration 3GPP (3rdgeneration partnership project) partnership project, e.g. GSM (global system for mobile communications for engl. Global System for Mobile Communications), EDGE (Increased Data Rate for GSM Evolution for Engl. Enhanced Data rates for GSM Evolution), GERAN (GSM EDGE radio access network. GSM EDGE Radio Access Network), HSPA (high-rate packet access for engl. High Speed Packet Access), UTRAN (Universal Terrestrial Radio Access Network. Universal Terrestrial Radio Access Network) or Evolved UTRAN (E-UTRAN), Long Term Evolution (LTE) or LTE-Advanced (LTE-A), or mobile communication systems with various standards, e.g. WIMAX (worldwide interoperability for microwave access for engl. Worldwide interoperability for microwave access) IEEE 802.16 or WLAN (wireless local area network. Wireless Local Area Network) IEEE 802.11, generally any system based on TDMA (Time Division Multiple Access). Time Division Multiple Access), FDMA (Frequency Division Multiple Access. Frequency Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access). Orthogonal Frequency Division Multiple Access), CDMA (Code Division Multiple Access). Code Division Multiple Access), etc. are based. The terms mobile communication system and mobile communication network can be used interchangeably.The mobile communication system may comprise a plurality of transmission points or base station transceivers operable to communicate radio signals with a mobile transceiver. In these examples, the mobile communication system may include mobile transceivers, relay station transceivers, and base station transceivers. The relay station transceivers and the base station transceivers may consist of one or more central units and one or more remote units.A mobile transceiver or mobile device may correspond to a smartphone, a cellular telephone, a user equipment (UE), a laptop, a notebook, a personal computer, a personal digital assistant (PDA), a universal serial bus (USB) stick, a tablet computer, a car, etc. A mobile transceiver or mobile terminal may also be referred to as a UE or user in accordance with 3GPP terminology. A base station transceiver may be located in the stationary or stationary part of the network or system. A base station transceiver may correspond to a remote radio head, a transmission point, an access point, a macrocell, a small cell, a microcell, a picocell, a femtocell, a metrocell, etc. The term "small cell" may refer to any cell that is smaller than a macrocell, i.e., a microcell, a picocell, a femtocell, or a metrocell. In addition, a femtocell is considered to be smaller than a picocell that is considered to be smaller than a microcell. A base station transceiver may be a wired network wireless interface that enables transmission and reception of radio signals to a UE, a mobile transceiver, or a relay transceiver.Such a radio signal may correspond to radio signals standardized by, for example, the 3GPP or generally consistent with one or more of the systems listed above. Thus, a base station transceiver may correspond to a NodeB, an eNodeB, a BTS, an access point, etc. A relay transceiver may correspond to an inter-network node in the communication path between a base station transceiver and a mobile station transceiver. A relay transceiver can transmit a signal received from a mobile transceiver to a base station transceiver or signals received from the base station transceiver to the mobile station transceiver.The mobile communication system may be cellular. The term "cell" refers to the coverage area of radio services provided by a transmission point, remote unit, remote head, remote radio head, base station transceiver, relay transceiver or NodeB, eNodeB. The terms "cell" and "base station transceiver" can be used interchangeably. In some examples, a cell may correspond to a sector. For example, sectors may be achieved using sector antennas that provide a characteristic for powering an angle section around a base station transceiver or remote unit. In some examples, a base station transceiver or remote unit may operate, for example, three or six cells serving sectors of 120° (in the case of three cells) and 60° (in the case of six cells), respectively. Likewise, a relay transceiver may define one or more cells in its coverage area. A mobile transceiver may be registered with or associated with at least one cell, i.e. it may be associated with a cell such that data may be exchanged between the network and the mobile in the coverage area of the associated cell using a dedicated channel, a dedicated transmission link or a dedicated connection. A mobile transceiver may therefore be directly or indirectly registered with or directly or indirectly associated with a relay station or base station transceiver, wherein indirect registration or association may be by one or more relay transceivers.FIG. 6 illustrates a flow diagram of a method 600 for determining information about a radiation power of a transmission signal. The method 600 comprises generating 610 a first radio frequency transmit signal from a first baseband signal and providing 620 a first radio frequency feed-forward signal at the feed-forward terminal of a first coupler module. Further, the method 600 comprises providing 630 a first radio frequency feedback signal at the feedback terminal of the first coupler module and generating 640 a first baseband feedforward signal from the first radio frequency feedforward signal. In addition, the method 600 comprises generating 650 a first baseband feedback signal from the first radio frequency feedback signal and determining 660 first forward power information based on the first baseband signal and the first baseband feedback signal. In addition, the method 600 comprises determining 670 first reverse power information based on the first baseband signal and the first baseband reverse feedback signal and generating 680 a first radiation power information signal comprising information indicative of a radiation power of the first radio frequency transmit signal based on the first forward power information and the first reverse power information.Further, the method 600 may include one or more additional operations corresponding to one or more aspects mentioned in connection with the described concept or one or more of the examples described above (e.g., FIGS. 1-3 ).FIG. 7 illustrates a flow diagram of a method 700 for determining information about a radiation power of a transmit signal. The method 700 comprises generating 710 a first radio frequency transmission signal from a first baseband signal and transmitting 720 at least a part of the first radio frequency transmission signal through a first antenna. Further, the method 700 comprises generating 730 a second baseband feedback signal from a second radio frequency feedback signal received by a second antenna and induced by the first radio frequency transmit signal, and generating 740 a first radiation power information signal comprising information indicative of a radiation power of the first radio frequency transmit signal based on the first baseband signal and the second baseband feedback signal.Further, the method 700 may include one or more additional operations corresponding to one or more aspects mentioned in connection with the described concept or one or more of the examples described above (e.g., FIGS. 1-3 ).The following examples are further given. Example 1 is an apparatus for determining information about a radiation power of a transmission signal. The apparatus comprises a first radio frequency generation module configured to generate a first radio frequency transmission signal from a first baseband signal, a first coupler module configured to provide a first radio frequency feed-forward signal based on the first radio frequency transmission signal to be transmitted by a first antenna and a first radio frequency feedback signal based on a reflected portion of the first radio frequency transmission signal received by the first antenna, and a radiation power determination module configured to determine first feed-forward power information based on the first baseband signal and the first radio frequency feed-forward signal and first reverse power information based on the first baseband signal and the first radio frequency feedback signal, wherein the radiation power determination module is configured to determine a first radiation power information signal comprising information, generating radiation power of the first high frequency transmission signal based on the first forward power information and the first reverse power information.Optionally, the apparatus may comprise a first baseband frequency generation module configured to generate a first baseband feedforward signal at least by down-mixing the first radio frequency feedforward signal and a first baseband feedback signal at least by down-mixing the first radio frequency feedback signal.Further, the radiation power determination module is optionally configured to determine at least one first forward correlation value representing the first forward power information based on the first baseband signal and the first baseband forward feedback signal and at least one first backward correlation value representing the first backward power information based on the first baseband signal and the first baseband backward feedback signal, wherein the radiation power determination module is configured to generate the first radiation power information signal comprising information indicative of radiation power of the first radio frequency transmission signal based on the at least one first forward correlation value and the at least one first backward correlation value.Optionally, the first coupler module comprises at least one input port coupled to the first radio frequency generation module, an output port to be coupled to at least the first antenna, a feed-forward port, and a feed-back port, wherein the first coupler module is configured to provide the first radio frequency feed-back signal at the feed-forward port and the first radio frequency feed-back signal at the feed-back port.In Example 2, the subject matter of Example 1 can optionally include a second radio frequency generation module configured to generate a second radio frequency transmit signal by at least up-mixing a second baseband signal, and at least one second antenna configured to transmit at least a portion of the second radio frequency transmit signal.In Example 3, the subject matter of Example 2 can optionally include the radiation power determination module configured to determine at least one first antenna coupling correlation value based on the second baseband signal and the first baseband feedback signal, wherein the radiation power determination module is configured to generate a second radiation power information signal comprising information indicative of a radiation power of the second radio frequency transmit signal based on the at least one first antenna coupling correlation value.In Example 4, the subject matter of Example 2 or 3 can optionally include a second coupler module comprising at least one input port coupled to the second radio frequency generation module, an output port to be coupled to the second antenna, a feed-forward port, and a feed-back port, wherein the second coupler module is configured to provide a second radio frequency feed-back signal at the feed-forward port and a second radio frequency feed-back signal at the feed-back port, and a second baseband generation module configured to generate a second baseband feed-back signal at least by a down-conversion of the second radio frequency feed-back signal and a second baseband feed-back signal at least by a down-conversion of the second radio frequency feed-back signal.In Example 5, the subject matter of Example 4 can optionally include the radiant power determination module configured to determine at least one second forward correlation value based on the second baseband signal and the second baseband forward feedback signal and at least one second backward correlation value based on the second baseband signal and the second baseband backward feedback signal, wherein the radiant power determination module is configured to generate the second radiant power information signal comprising information indicative of a radiant power of the second radio frequency transmit signal based on the at least one second forward correlation value, the at least one second backward correlation value, and the at least one first antenna coupling correlation value.In Example 6, the subject matter of Example 5 can optionally include a second baseband frequency generation module to couple to a second antenna and configured to generate a second baseband feed-forward signal at least by down-mixing a second radio frequency feed-back signal.In Example 7, the subject matter of Example 5 or 6 can optionally include the radiation power determination module configured to determine at least one second antenna coupling correlation value based on the first baseband signal and the second baseband feedback signal, wherein the radiation power determination module is configured to generate the first radiation power information signal comprising information indicative of a radiation power of the first radio frequency transmit signal based on the at least one first forward correlation value, the at least one first reverse correlation value, and the at least one second antenna coupling correlation value.In Example 8, the subject matter of any one of Examples 1 to 7 can optionally include the first radio frequency feed-forward signal substantially caused by the first radio frequency transmit signal received at the input port of the first coupler module, wherein the first radio frequency feed-back signal is substantially caused by a reverse wave signal received at the output port of the first coupler module.In Example 9, the subject matter of any one of Examples 1 to 8 can optionally include the first baseband frequency generation module comprising a feedback receiver module configured to generate the first baseband feedforward signal at least by down-mixing the first radio frequency feedforward signal during a first time interval and generate the first baseband feedback signal at least by down-mixing the first radio frequency feedback signal during a second time interval.In Example 10, the subject matter of any one of Examples 1 to 9 can optionally include the first baseband frequency generation module comprising a first feedback receiver module configured to generate the first baseband feedforward signal at least by down-mixing the first radio frequency feedforward signal, and a second feedback receiver module generating the first baseband feedback signal at least by down-mixing the first radio frequency feedback signal during a second time interval.In Example 11, the subject matter of any one of Examples 1 to 10 can optionally include a first power amplifier module and a first power control module, wherein the first power amplifier module is configured to amplify the first radio frequency transmit signal before the first radio frequency transmit signal is provided to the transmit port of the first coupler module, wherein the first power control module is configured to control a gain of the first power amplifier module based on the first radiation power information signal.In Example 12, the subject matter of any one of Examples 1 to 11 can optionally include the first coupler module comprising a first directional coupler comprising at least the input port coupled to the first radio frequency generation module, the output port to be coupled to at least the first antenna, the feed-forward port, and the feed-back port.In Example 13, the subject matter of any one of Examples 1 to 12 can optionally include the radiation power determination module configured to determine the at least one first forward correlation values based on a cross correlation function of the first baseband signal and the first baseband feed-forward signal and the at least one first reverse correlation values based on a cross correlation function of the first baseband signal and the first baseband feed-back signal.In Example 14, the subject matter of any one of Examples 1 to 13 can optionally include the radiant power determination module configured to determine the at least one first forward correlation value at least by determining at least one expected value based on the first baseband signal and the first baseband feed-forward signal and the at least one first reverse correlation value at least by determining at least one expected value based on the first baseband signal and the first baseband feed-back signal.In Example 15, the subject matter of Example 14 can optionally include the radiant power determination module configured to determine an expected value over a number of symbol intervals between 50 and 5000.In Example 16, the subject matter of any one of Examples 1 to 15 can optionally include the radiant power determination module configured to generate the first radiant power information signal based on a first forward correlation accumulation value determined based on an accumulation function of the at least one first forward correlation value and a first backward correlation accumulation value determined based on an accumulation function of the at least one first backward correlation value.In Example 17, the subject matter of Example 16 can optionally include the radiant power determination module configured to generate the first radiant power information signal based on a subtraction of the first backward correlation accumulation value from the first forward correlation accumulation value.In Example 18, the subject matter of any one of Examples 16 to 17 can optionally include the radiant power determination module configured to generate the first radiant power information signal based on the first forward correlation accumulation value determined based on the accumulation function of the at least one first forward correlation value, the first backward correlation accumulation value determined based on the accumulation function of the at least one first backward correlation value, and a second antenna coupling correlation accumulation value determined based on an accumulation function of the at least one second antenna coupling correlation value.In Example 19, the subject matter of Example 18 can optionally include the radiant power determination module configured to generate the first radiant power information signal based on a subtraction of the first backward correlation accumulation value and the second antenna coupling correlation accumulation value from the first forward correlation accumulation value.In Example 20, the subject matter of any one of Examples 1 to 19 can optionally include the first baseband frequency generation module further configured to generate a baseband receive signal based on down-conversion of a radio frequency receive signal received from an external transmitter.In Example 21, the subject matter of any one of Examples 1 to 20 can optionally include the first radio frequency generation module, the first coupler module, and the first baseband frequency generation module implemented on the same semiconductor chip.Example 22 is an apparatus for determining information about a radiation power of a transmission signal. The apparatus comprises first upconversion means configured to generate a first radio frequency transmit signal by at least upconversion of a first baseband signal, and first coupling means comprising at least one input terminal coupled to the first radio frequency generation module, an output terminal to be coupled to at least one first antenna, a feed-forward terminal, and a feed-back terminal, wherein the first coupling means are configured to provide a first radio frequency feed-back signal at the feed-forward terminal and a first radio frequency feed-back signal at the feed-back terminal. Further, the apparatus comprises first downmix means configured to generate a first baseband feedforward signal at least by downmix of the first radio frequency feedforward signal and a first baseband feedback signal at least by downmix of the first radio frequency feedback signal, and means for determining radiation power information configured to determine at least a first feedforward correlation value based on the first baseband signal and the first baseband feedforward signal and at least a backward correlation value based on the first baseband signal and the first baseband feedback signal, wherein the means for determining radiation power information is configured to determine a first radiation power information signal comprising information indicative of radiation power of the first radio frequency transmit signal, generating based on the at least one first forward correlation value and the at least one first backward correlation value.In Example 23, the subject matter of Example 22 can optionally include second upconversion means configured to generate a second radio frequency transmit signal by at least upconversion of a second baseband signal and at least one second antenna configured to transmit at least a portion of the second radio frequency transmit signal, wherein the means for determining radiant power information is configured to determine at least one first antenna coupling correlation value based on the second baseband signal and the first baseband reverse feedback signal, wherein the means for determining radiant power information is configured to generate a second radiant power information signal comprising information indicative of a radiant power of the second radio frequency transmit signal based on the at least one first antenna coupling correlation value.Example 24 is an apparatus for determining information about a radiation power of a transmission signal. The apparatus includes a first radio frequency generation signal configured to generate a first radio frequency transmission signal to be transmitted by a first antenna from a first baseband signal, a second baseband frequency generation module configured to couple to a second antenna and configured to generate a second baseband feedback signal from a second radio frequency feedback signal caused by the first radio frequency transmission signal, and a radiation power determination module configured to generate a first radiation power information signal including information indicating radiation power of the first radio frequency transmission signal based on the first baseband signal and the second baseband feedback signal.In Example 25, the subject matter of Example 24 can optionally include a second radio frequency signal generation module configured to generate a second radio frequency transmit signal by at least up-mixing a second baseband signal, and a first coupler module comprising at least one input port coupled to the first radio frequency generation module, an output port to be coupled to a first antenna, and a feedback port, wherein the first coupler module is configured to provide a first radio frequency feedback signal at the feedback port.Example 26 is an apparatus for determining information about a radiation power of a transmission signal. The apparatus comprises a first radio frequency generation module configured to generate a first radio frequency transmit signal from a first baseband signal and a second radio frequency generation module configured to generate a second radio frequency transmit signal at least by up-mixing a second baseband signal. Further, the apparatus comprises a first coupler module comprising at least one input port coupled to the first radio frequency generation module, an output port to be coupled to a first antenna, and a feedback port, wherein the first coupler module is configured to provide a first radio frequency feedback signal at the feedback port, and at least one second antenna configured to transmit at least a portion of the second radio frequency transmit signal. In addition, the apparatus includes a first baseband frequency generation module configured to generate a first baseband feedback signal from the first radio frequency feedback signal, and a radiation power determination module configured to generate a second radiation power information signal including information indicating radiation power of the second radio frequency transmission signal based on the second baseband signal and the first baseband feedback signal.In Example 27, the subject matter of Example 26 can optionally include a second coupler module comprising at least one input port coupled to the second radio frequency generation module, an output port to be coupled to the second antenna, a feed-forward port, and a feed-back port, wherein the second coupler module is configured to provide a second radio frequency feed-back signal at the feed-back port of the second coupler module, wherein the second coupler module is configured to provide a second radio frequency feed-back signal at the feed-back port of the second coupler module, and a second baseband frequency generation module configured to:, generating a second baseband feed-forward signal by at least a down-conversion of the second radio frequency feed-forward signal and a second baseband feed-back signal by at least a down-conversion of the second radio frequency feed-back signal, wherein the radiation power determination module is configured to determine at least a second feed-forward correlation value based on the second baseband signal and the second baseband feed-forward signal, at least a second feed-back correlation value based on the second baseband signal and the second baseband feed-back signal, and at least a first antenna coupling correlation value based on the second baseband signal and the first baseband feed-back signal, wherein the radiation power determination module is configured to determine the second radiation power information signal comprising information indicative of a radiation power of the second radio frequency transmit signal based on the at least a second feed-forward correlation value, generating the at least one second backward correlation value and the at least one first antenna coupling correlation value.Example 28 is a transmitter or a transceiver comprising an apparatus according to any one of examples 1 to 27.Example 29 is a mobile device comprising a transmitter or transceiver according to example 28.Example 30 is a cellular telephone comprising a transmitter or transceiver according to example 28.Example 31 is a method for determining information about a radiation power of a transmission signal. The method includes generating a first radio frequency transmit signal from a first baseband signal, providing a first radio frequency feed-forward signal at a feed-forward port of a first coupler module, providing a first radio frequency feed-back signal at a feed-back port of the first coupler module, generating a first baseband feed-forward signal from the first radio frequency feed-forward signal, generating a first baseband feed-back signal from the first radio frequency feed-back signal, determining first feed-forward power information based on the first baseband signal and the first baseband feed-forward signal, determining first feed-back power information based on the first baseband signal and the first baseband feed-back signal, and generating a first radiant power information signal comprising information indicative of a radiant power of the first radio frequency transmit signal, based on the first forward power information and the first reverse power information.In Example 32, the subject matter of Example 31 can optionally include generating a second radio frequency transmit signal by at least up-mixing a second baseband signal, transmitting at least a portion of the second radio frequency transmit signal, determining at least a first antenna coupling correlation value based on the second baseband signal and the first baseband feedback signal, and generating a second radiant power information signal comprising information indicative of a radiant power of the second radio frequency transmit signal based on the at least a first antenna coupling correlation value.Example 33 is a method for determining information about a radiation power of a transmission signal. The method includes generating a first radio frequency transmit signal from a first baseband signal, transmitting at least a portion of the first radio frequency transmit signal through a first antenna, generating a second baseband feedback signal from a second radio frequency feedback signal received through a second antenna and induced by the first radio frequency transmit signal, and generating a second radiant power information signal including information indicative of a radiant power of the first radio frequency transmit signal based on the first baseband signal and the second baseband feedback signal.In Example 34, the subject matter of Example 33 can optionally include generating a second radio frequency transmit signal at least by up-mixing a second baseband signal and providing a first radio frequency feedback signal at the feedback port of a first coupler module.Example 35 is a machine readable storage medium including program code that, when executed, causes a machine to perform the method of any of Examples 31 or 33.Example 36 is a machine readable memory comprising machine readable instructions that, when executed, implement a method or implement an apparatus as implemented by any of Examples 1 to 34.Example 37 is a computer program having a program code for performing the method of example 31 or 33 when the computer program is executed on a computer or processor.Examples may further provide a computer program having a program code for performing one of the methods described above when the computer program is executed on a computer or processor. It will be readily appreciated by those skilled in the art that the steps of the various methods described above may be performed by programmed computers. It is intended that some examples herein also include program storage devices, e.g., digital storage media, that are machine- or computer-readable and encode machine- or computer-executable programs of instructions, the instructions performing some or all of the operations of the methods described above. The program storage devices can be, for example, digital memories, magnetic storage media, such as magnetic disks and magnetic tapes, hard disks or optically readable digital data storage media. It is also intended that the examples include computers programmed to perform the operations of the methods described above, or (field) programmable logic arrays ((F)PLAs) or (field) programmable gate arrays ((F)PGAs) programmed to perform the operations of the methods described above.The specification and drawings merely illustrate the principles of the disclosure. It is therefore to be understood that various arrangements may be devised by those skilled in the art which, although not expressly described or illustrated herein, embody the principles of the disclosure and fall within its spirit and scope. Moreover, all examples mentioned herein are for paedagogical purposes only to facilitate the reader's understanding of the invention and the concepts that the inventor / s contribute to promoting the art, and are therefore to be construed as not limiting such specific examples and conditions mentioned. Moreover, all statements herein which may invoke principles, aspects, and examples of the disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof.Function blocks referred to as "means for... " (performing a certain function) are to be understood as function blocks including circuit arrangement each configured to perform a certain function. As a result, a "means for something" is also to be understood as a "means configured to or suitable for something". A means configured to perform a particular function therefore does not necessarily assume that such a means performs the function (at a particular time).Functions of various elements illustrated in the figures, including all the function blocks referred to as "means", "means for providing a sensor signal", "means for generating a transmission signal", etc., may be provided through the use of dedicated hardware such as "a signal providing device", "a signal processing unit", "a processor", "a controller", etc., as well as hardware capable of executing software in conjunction with appropriate software. Moreover, any functional unit described herein as "means" may correspond to or be implemented as "one or more modules", "one or more devices", "one or more units", etc. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Additionally, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, but may implicitly include, but is not limited to, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), and nonvolatile memory. Other, conventional and / or customized hardware may also be included.It should be appreciated by those skilled in the art that all block diagrams herein represent conceptual views of illustrated circuitry embodying the principles of the disclosure. Similarly, it will be understood that all flow charts, flowcharts, state transition diagrams, pseudo code, and the like represent various processes that are substantially embodied in a computer readable medium and thus may be executed by a computer or processor, whether or not such a computer or processor is explicitly illustrated.Moreover, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate example. Although each claim may stand on its own as a separate example, it should be noted that - although a dependent claim in the claims may refer to a specific combination with one or more other claims - other examples may also comprise a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are proposed herein unless it is indicated that a specific combination is not intended. It is also intended to include features of a claim in any other independent claim, although that claim is not made directly dependent on the independent claim.It is further to be noted that the methods disclosed in the specification or claims may be implemented by an apparatus having means for performing each of the respective operations of these methods.Further, it is to be understood that the disclosure of multiple acts or functions disclosed in the specification or claims should not be construed as being in the specific order. Therefore, the disclosure of multiple acts or functions does not limit them to a particular order unless such acts or functions are not interchangeable for technical reasons. Additionally, in some examples, a single operation may include or be divided into multiple sub-operations. Such sub-operations may be part of the disclosure of or be included in this single operation, unless expressly excluded.

Claims

An apparatus (100, 200, 300) for determining information about a radiation power of a transmit signal, the apparatus comprising: a first radio frequency generation module (110) configured to generate a first radio frequency transmit signal (112) from a first baseband signal (102); a first coupler module (120) configured to provide a first radio frequency feed-forward signal (122) based on the first radio frequency transmit signal (112) to be transmitted by a first antenna (104) and a first radio frequency feed-back signal (124) based on a reflected portion of the first radio frequency transmit signal (112) received by the first antenna (104); a radiation power determination module (140) configured to determine first forward power information based on the first baseband signal (102) and the first high frequency forward feedback signal (122), and first reverse power information based on the first baseband signal (102) and the first high frequency reverse feedback signal (124), wherein the radiation power determination module (140) is configured to generate a first radiation power information signal (142) comprising information indicative of a radiation power of the first high frequency transmit signal (112) based on the first forward power information and the first reverse power information; and a first power amplifier module (360) and a first power control module (350), wherein the first power amplifier module (360) is configured to amplify the first radio frequency transmit signal (112) before the first radio frequency transmit signal (112) is provided to the first coupler module (120), wherein the first power control module (350) is configured to control a gain of the first power amplifier module (360) based on the first radiation power information signal (142).An apparatus (100, 200, 300) for determining information about a radiation power of a transmit signal, the apparatus comprising: a first radio frequency generation module (110) configured to generate a first radio frequency transmit signal (112) from a first baseband signal (102); a first coupler module (120) configured to provide a first radio frequency feed-forward signal (122) based on the first radio frequency transmit signal (112) to be transmitted by a first antenna (104) and a first radio frequency feed-back signal (124) based on a reflected portion of the first radio frequency transmit signal (112) received by the first antenna (104); a radiation power determination module (140) configured to:, determining first forward power information based on the first baseband signal (102) and the first high frequency forward feedback signal (122) and first reverse power information based on the first baseband signal (102) and the first high frequency reverse feedback signal (124), wherein the radiation power determining module (140) is configured to generate a first radiation power information signal (142) comprising information indicative of a radiation power of the first high frequency transmit signal (112) based on the first forward power information and the first reverse power information, wherein the radiation power determining module (140) is configured to:, determining the at least one first forward correlation value at least by determining at least one expected value based on the first baseband signal (102) and the first baseband forward feedback signal (132) and the at least one first backward correlation value at least by determining at least one expected value based on the first baseband signal (102) and the first baseband backward feedback signal (134), wherein the radiation power determining module (140) is configured to generate the first radiation power information signal (142) based on a first forward correlation accumulation value determined based on an accumulation function of the at least one first forward correlation value and a first backward correlation accumulation value determined based on an accumulation function of the at least one first backward correlation value.The apparatus of claim 1 or 2, further comprising a first baseband frequency generation module (130) configured to generate a first baseband feedforward signal (132) at least by down-mixing the first radio frequency feedforward signal (122) and a first baseband feedback signal (134) at least by down-mixing the first radio frequency feedback signal (124).The apparatus of claim 3, wherein the radiant power determination module (140) is configured to determine at least one first forward correlation value representing the first forward power information based on the first baseband signal (102) and the first baseband forward feedback signal (132) and at least one first backward correlation value representing the first backward power information based on the first baseband signal (102) and the first baseband backward feedback signal (134), wherein the radiant power determination module (140) is configured to generate the first radiant power information signal (142) comprising information indicative of a radiant power of the first radio frequency transmit signal (112) based on the at least one first forward correlation value and the at least one first backward correlation value.The apparatus of any of claims 1 to 4, wherein the first coupler module (120) comprises at least one input port coupled to the first radio frequency generation module (110), an output port to be coupled to at least the first antenna (104), a feed-forward port, and a feedback port, wherein the first coupler module (120) is configured to provide the first radio frequency feed-forward signal (122) at the feed-forward port and the first radio frequency feed-back signal (124) at the feedback port.The apparatus of any of claims 1 to 5, further comprising: a second radio frequency generation module (260) configured to generate a second radio frequency transmit signal (262) from a second baseband signal (252); and at least one second antenna (254) configured to transmit at least a portion of the second radio frequency transmit signal (262).The apparatus of claim 6, wherein the radiation power determination module (140) is configured to determine first antenna (104) coupling power information based on the second baseband signal (252) and the first radio frequency feedback signal (124), wherein the radiation power determination module (140) is configured to generate a second radiation power information signal (444) comprising information indicative of radiation power of the second radio frequency transmit signal (462) based on the first antennas (104) coupling power information.The apparatus of claim 6 or 7, further comprising: a second coupler module (270) comprising at least one input port coupled to the second radio frequency generation module (260), an output port to be coupled to the second antenna (254), a feed-forward port, and a feed-back port, wherein the second coupler module (270) is configured to provide a second radio frequency feed-back signal (272) at the feed-forward port and a second radio frequency feed-back signal (274) at the feed-back port; and a second baseband frequency generation signal configured to generate a second baseband feedforward signal (232) by at least down-converting the second radio frequency feedforward signal (272) and a second baseband feedback signal (234) by at least down-converting the second radio frequency feedback signal (274).The apparatus of claim 8, wherein the radiation power determination module (140) is configured to determine second forward power information based on the second baseband signal (252) and the second baseband forward feedback signal (232), and second reverse power information based on the second baseband signal (252) and the second baseband reverse feedback signal (234), wherein the radiation power determination module (140) is configured to generate the second radiation power information signal comprising information indicative of radiation power of the second radio frequency transmit signal (262) based on the second forward power information, the second reverse power information, and the first antennas (104) coupling power information.The apparatus of any of claims 1 to 9, comprising a second baseband frequency generation module to be coupled to a second antenna and configured to generate a second baseband feedback signal (234) from a second radio frequency feedback signal (274).The apparatus of claim 10, wherein the radiation power determination module (140) is configured to determine second antenna coupling power information based on the first baseband signal (102) and the second baseband feedback signal (234), wherein the radiation power determination module (140) is configured to generate the first radiation power information signal (142) comprising information indicative of radiation power of the first radio frequency transmit signal (112) based on the first forward power information, the first reverse power information, and the second antenna coupling power information.The apparatus of any of claims 1 to 11, wherein the first radio frequency feed-back signal (122) is substantially caused by the first radio frequency transmit signal (112) received at the input port of the first coupler module (120), wherein the first radio frequency feed-back signal (124) is substantially caused by a reverse wave signal received at the output port of the first coupler module (120).The apparatus of any of claims 1 to 12, wherein the first baseband frequency generation module (130) comprises a feedback receiver module (232) configured to generate the first baseband feedforward signal (132) at least by down-mixing the first radio frequency feedforward signal (122) during a first time interval and the first baseband feedback signal (134) at least by down-mixing the first radio frequency feedback signal (124) during a second time interval.The apparatus of any of claims 1 to 13, wherein the first baseband frequency generation module (130) comprises a first feedback receiver module (232) configured to generate the first baseband feedforward signal (132) at least by down-mixing the first radio frequency feedforward signal (122), and a second feedback receiver module (282) configured to generate the first baseband feedback signal (134) at least by down-mixing the first radio frequency feedback signal (124) during a second time interval.The apparatus of any of claims 1 to 14, wherein the first coupler module (120) comprises a first directional coupler comprising at least the input port coupled to the first radio frequency generation module (110), the output port to be coupled to at least the first antenna (104), the feed-forward port, and the feed-back port.The apparatus of any of claims 1 to 15, wherein the radiation power determination module (140) is configured to determine the at least one first forward correlation value based on a cross correlation function of the first baseband signal (102) and the first baseband forward feedback signal (132) and determine the at least one first backward correlation value based on a cross correlation function of the first baseband signal (102) and the first baseband backward feedback signal (134).The apparatus of claim 2, wherein the radiant power determination module (140) is configured to determine an expected value over a number of symbol intervals between 50 and 5000.An apparatus (490) for determining information about a radiant power of a transmit signal, the apparatus comprising: a first radio frequency generation module (410) configured to generate a first radio frequency transmit signal (412) to be transmitted by a first antenna (404) from a first baseband signal (402); a second baseband frequency generation module (492) to be coupled to a second antenna (454) and configured to generate a second baseband feedback signal (434) from a second radio frequency feedback signal (424) caused by the first radio frequency transmit signal (412); a radiation power determination module (440) configured to generate a first radiation power information signal (444) comprising information indicative of radiation power of the first radio frequency transmit signal (412) based on the first baseband signal (402) and the second baseband feedback signal (434); a power amplifier module and a power control module, the power amplifier module configured to amplify the first radio frequency transmit signal (412), the power control module (410) configured to control a gain of the power amplifier module based on the first radiation power information signal (444).The apparatus (490) of claim 18, further comprising: a second radio frequency generation module (460) configured to generate a second radio frequency transmit signal (462) from a second baseband signal (452); a first coupler module (420) comprising at least one input port coupled to the first radio frequency generation module (410), an output port to be coupled to the first antenna, and a feedback port, wherein the first coupler module (420) is configured to provide a first radio frequency feedback signal (424) at the feedback port.An apparatus (400) for determining information about a radiation power of a transmit signal, the apparatus comprising: a first radio frequency generation module (410) configured to generate a first radio frequency transmit signal (412) from a first baseband signal (402); a second radio frequency generation module (460) configured to generate a second radio frequency transmit signal (462) from a second baseband signal (452); a first coupler module (420) comprising at least one input port coupled to the first radio frequency generation module (410), an output port coupled to a first antenna (404), and a feedback port, wherein the first coupler module (420) is configured to provide a first radio frequency feedback signal (424) at the feedback port; at least one second antenna (454) configured to transmit at least a portion of the second radio frequency transmit signal (462); a first baseband frequency generation module (430) configured to generate a first baseband feedback signal (434) from the first radio frequency feedback signal (424); and a radiation power determination module (440) configured to generate a second radiation power information signal (444) comprising information indicative of a radiation power of the second radio frequency transmit signal (462) based on the second baseband signal (452) and the first baseband feedback signal (434); a power amplifier module and a power control module, the power amplifier module configured to amplify the second radio frequency transmit signal (462), the power control module configured to control a gain of the power amplifier module based on the second radiation power information signal (444).A transmitter or transceiver comprising an apparatus (100; 200; 300; 400; 490) according to any of claims 1 to 20.A method (600) for determining information about a radiation power of a transmit signal, the method comprising: generating (610) a first radio frequency transmit signal from a first baseband signal; providing (620) a first radio frequency feed-forward signal at a feed-forward port of a first coupler module; providing (630) a first radio frequency feed-back signal at a feed-back port of the first coupler module; generating (640) a first baseband feed-forward signal from the first radio frequency feed-forward signal; generating (650) a first baseband feed-back signal from the first radio frequency feed-back signal; determining (660) first feed-forward power information based on the first baseband signal and the first baseband feed-back signal; determining (670) first reverse power information based on the first baseband signal and the first baseband reverse feedback signal; and generating (680) a first radiation power information signal comprising information indicative of radiation power of the first radio frequency transmission signal based on the first forward power information and the first reverse power information, amplifying the first radio frequency transmission signal, wherein amplification of the first radio frequency transmission signal is controlled based on the first radiation power information signal.A computer program comprising program code for performing the method of claim 22, when the computer program is executed on a computer or processor.

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