Circuit device and method for identifying a frequency band or a channel

Abstract

The present invention relates to a circuit device for transmitting uplink signals and downlink signals between at least one terminal device (2) and at least one antenna (5), wherein the circuit device (1) includes at least one signal coupler (9) for providing a decoupled uplink signal or downlink signal, wherein the circuit device (1) includes at least one device (15) for providing a reference signal with an adjustable frequency, wherein the circuit device (1) includes at least one mixer (14) for mixing the decoupled signal and the reference signal and at least one filter device (16) for low-pass or band-pass filtering of the mixed signals, wherein the circuit device (1) includes at least one evaluation device (7) for evaluating the filtered signal, wherein at least one frequency band (FB1, FB2, FB3) or at least one channel (K1, …, K6) in which the signal being transmitted is being transmitted can be identified depending on the adjusted frequency of the reference signal and at least one signal characteristic of the filtered signal, and the present invention also relates to a method for identifying a frequency band (FB1, FB2, FB3) or a channel (K1, …, K6).

Description

Field of the Invention

[0001] The present invention relates to a circuit arrangement for transmitting uplink signals and downlink signals between at least one terminal device and at least one antenna, and also to a method for identifying a frequency band or a channel. Background Art

[0002] DE102017209209A1 discloses a signal coupling device and a method for operating the signal coupling device. The signal coupling device includes a transmission activity detection device. By means of this device, a transmission activity can be specifically detected for a transmission band. In other words, an active transmission band can be identified, wherein a transmission signal is being transmitted in the active transmission band.

[0003] It is desirable to identify the frequency band or channel in which an uplink signal or a downlink signal is being transmitted. By means of a circuit arrangement for signal transmission and / or the creation of a required signal path of the circuit arrangement, such identification can be used to perform a required signal processing, in particular a required signal amplification. For example, it may be desirable to only activate those amplifier devices in the circuit arrangement that amplify the signals being transmitted in the corresponding frequency band or the corresponding channel. Other amplifier devices can be deactivated here, thereby reducing the power consumption of the circuit arrangement.

[0004] Known transmission activity detection devices typically include a large number of filter devices, such as band-pass filters, for filtering frequency-band-specific signals. The use of the large number of filter devices thus results in production costs and requires a large amount of installation space.

[0005] In addition, known devices include a large number of amplifiers, switching elements, and a broadband detector. This requires a complex structure of the circuit arrangement. Summary of the Invention

[0006] The technical problem is to provide a circuit arrangement for transmitting uplink signals and downlink signals between at least one terminal device and at least one antenna, and a method for identifying a frequency band or a channel, which can accurately, reliably, and quickly identify the frequency band or channel, wherein the production cost and complexity of the circuit arrangement are reduced.

[0007] This technical problem is solved by an object having the features of the independent claims. In addition, advantageous embodiments of the present invention result from the dependent claims.

[0008] A circuit device is proposed for transmitting uplink signals and downlink signals between at least one terminal device and at least one antenna. With the aid of the circuit device, losses in the transmission of these uplink signals and downlink signals can be compensated, for example losses on signal transmission components.

[0009] The terminal device can be a portable terminal device, for example a terminal device that can be carried by a user. Such a terminal device can be, for example, a mobile phone or a tablet computer. Additionally, the terminal device can also be a modem or a control device, in particular a modem or a control device in a vehicle, such as a telematics control unit. The terminal device can thus also be a permanently installed terminal device, for example a terminal device permanently installed in a vehicle.

[0010] Multiple uplink signals can be transmitted by the circuit device. Preferably, multiple uplink signals having multiple frequencies from mutually different uplink frequency bands can be transmissible, where an uplink signal transmitted in an uplink frequency band has a frequency from that band. This is also referred to as interband carrier aggregation. If multiple uplink signals are transmitted in different channels of a frequency band, this can be referred to as intraband carrier aggregation.

[0011] Mutually different uplink frequency bands can be used for transmitting uplink signals according to one radio standard or different radio standards. Such standards can be, for example, a GSM standard, a UMTS standard, an LTE standard, a Wi-Fi or a 5G New Radio standard.

[0012] An uplink frequency band can be precisely assigned to one standard but can also be precisely assigned to multiple standards. Thus, multiple uplink signals can be transmitted in the same uplink frequency band according to different standards. If a frequency of an uplink signal is recognized / detected, then in this case, the standard can only be determined by means of an additional signal analysis.

[0013] For example, multiple signals can be transmitted in an uplink frequency band according to GSM and / or LTE and / or UMTS and / or other standards.

[0014] Multiple downlink signals can also be transmitted by the circuit device. An inter-band or intra-band carrier aggregation can thus also be in the transmission of multiple downlink signals. Multiple downlink signals having multiple frequencies from mutually different downlink frequency bands can preferably be transmitted, wherein a downlink signal transmitted in a downlink frequency band has a frequency from that band. Mutually different downlink frequency bands can in particular be used to transmit multiple downlink signals according to the various standards mentioned. Here, a downlink frequency band can be precisely assigned to one standard but can also be precisely assigned to multiple standards. Thus, multiple downlink signals can be transmitted according to different standards in the same downlink frequency band. If a frequency of a downlink signal is recognized / detected, then in this case, the standard is determined only by means of an additional signal analysis.

[0015] In addition, the uplink signal and the downlink signal can be transmitted in a time-division duplex mode (also referred to as the TDD mode (time-division duplex mode)) or in a frequency-division duplex mode (also referred to as the FDD mode (frequency-division duplex mode)). The present invention is not limited to the aforementioned radio standards or duplex modes and thus relates to all radio standards and duplex modes known to those skilled in the art as well as future radio standards and duplex modes.

[0016] The circuit device can include a terminal device side interface. This can represent an interface via which a signal-related connection can be established between the circuit device and the terminal device. In this case, the terminal device side interface can enable a two-way transmission of signals. For example, the terminal device side interface can include a so-called wireless coupler.

[0017] In addition, the circuit device can precisely include one antenna side interface or multiple antenna side interfaces. This can represent an interface via which a signal-related connection can be established between the circuit device and one or more antennas. The antenna can be an antenna external to the terminal device. However, the antenna can also be part of the circuit device. In particular, the antenna can be used to receive a signal transmitted by a base station. In addition, the antenna can be used to transmit a signal that will be sent to the base station or another device. Here, the antenna side interface can enable a two-way transmission of signals.

[0018] The circuit device can be arranged in a vehicle, in particular a motor vehicle. In this case, the antenna external to the terminal device can in particular be a vehicle antenna. The circuit device can also in particular be part of a mobile radio amplification device or include or form a mobile radio amplification device.

[0019] For the purposes of the present invention, a connection can represent a connection related to a signal. This particularly refers to a galvanic and / or inductive and / or capacitive connection. A connection is preferably a galvanic connection. The components of the circuit arrangement can preferably be connected by galvanic and inductive connections. However, the connection of the circuit arrangement to the terminal device can be an inductive connection or a capacitive connection.

[0020] An uplink path can here represent a signal path via which an uplink signal can be transmitted from the terminal device-side interface to the antenna-side interface. The uplink signal can in particular represent a signal generated by the terminal device and transmitted to the terminal device-side interface.

[0021] Here, a downlink path can represent a signal path via which a downlink signal can be transmitted from the antenna-side interface to the terminal device-side interface. The downlink signal can in particular represent a signal received by the antenna external to the terminal device and transmitted by, for example, the base station.

[0022] Signal processing means can be arranged in an uplink path and / or a downlink path. This can mean that the transmission of a signal via one of these signal paths can be carried out via active and / or passive signal processing means. For example, the signal transmission can be carried out via at least one amplifier device and / or at least one attenuator device and / or at least one signal filter device and / or at least one signal switching device.

[0023] The circuit arrangement includes at least one signal coupler for providing a decoupled uplink signal or downlink signal. For example, the signal coupler can decouple an uplink signal transmitted via an uplink path from that uplink path. Accordingly, the signal coupler can also decouple a downlink signal transmitted via a downlink from that downlink path.

[0024] In particular, the signal coupler can be arranged and / or designed in such a way that a signal present at the aforementioned terminal device-side interface is decoupled. The design of a suitable signal coupler is known to the person skilled in the art. In particular, the signal coupler can provide a decoupled signal having a lower power than the transmitted uplink signal or downlink signal, but wherein the decoupled signal otherwise has the same signal characteristics as the transmitted uplink signal or downlink signal.

[0025] According to the present invention, the circuit device includes at least one means for providing a reference signal with an adjustable frequency. Thus, a signal with a desired frequency can be provided by this means. In this case, for example, the frequency can be adjusted by a control device of the circuit device. Here, the control device can be formed by a control and evaluation device. In this case, the control device or the control and evaluation device can be designed as a microcontroller or an integrated circuit or include one of the microcontroller and the integrated circuit.

[0026] In addition, the circuit device includes at least one mixer for mixing the decoupled signal and the reference signal and at least one filter device for low-pass or band-pass filtering of the mixed signal. By means of the mixer, an output signal can be generated, which includes a component of one or more frequencies of the reference signal, a component of one or more frequencies of the decoupled signal, a component of a frequency corresponding to the difference magnitude between one or more frequencies of the reference signal and one or more frequencies of the decoupled signal (especially the carrier frequency), a component of a frequency corresponding to the sum of one or more frequencies of the reference signal and one or more frequencies of the decoupled signal (especially the carrier frequency), and integral multiples of these components.

[0027] In particular, the output signal of the mixer thus includes a difference component with another frequency, and the other frequency is equal to the difference magnitude between the frequency of the reference signal and the carrier frequency of the decoupled signal. The output signal may also include another signal component with another frequency, especially a so-called frequency mixture component.

[0028] The filter device can especially be a low-pass filter or a band-pass filter. As will be explained in more detail below, the cut-off frequency of the low-pass filter or the band-pass filter can be adjustable. For example, the cut-off frequency can be adjusted by the aforementioned control device. By adjusting the cut-off frequency, in particular, it can be achieved that the mentioned difference component is filtered out from the output signal of the mixer and then used for subsequent analysis.

[0029] The filter device can especially be a programmable filter device. In particular, the filter device can also be a digital filter device, for example, a digital low-pass filter or a digital band-pass filter.

[0030] Furthermore, the circuit arrangement includes at least one evaluation device for evaluating the filtered signal. The evaluation device can be formed by the aforementioned control and evaluation device. Depending on the design of the control device, the evaluation device can also be designed as a microcontroller or an integrated circuit or include one of the microcontroller and the integrated circuit.

[0031] At least one signal characteristic of the filtered signal can be evaluated by the evaluation device. Here, the at least one signal characteristic can be determined by the evaluation device. The at least one signal characteristic can in particular be a signal power. A signal power can in particular be represented by a signal level. The signal characteristic can be determined for a predetermined time period (e.g., 50 μs). In this case, the predetermined time period depends on the number of frequency bands to be investigated and the time period of a signal burst during which the required frequency band or channel identification can be carried out. The time period can be in a range between 10 μs and 100 μs, preferably in a range between 20 μs and 50 μs. However, depending on the application, the time period can also be in the range of 1 to several ms (e.g., up to 10 ms).

[0032] For example, the signal characteristic can be compared with a predetermined threshold. Of course, other forms of evaluation can also be conceived.

[0033] Furthermore, in particular by means of the evaluation device, at least one frequency band or at least one channel in which the transmitted signal is transmitted can be identified as a function of the adjusted frequency of the reference signal and at least one signal characteristic of the filtered signal. It is conceivable to precisely identify a frequency band or precisely identify a channel. However, multiple frequency bands or multiple channels in which a signal is transmitted can also be identified.

[0034] In this case, a frequency band can include multiple channels. A channel here represents a sub-band of the frequency band, which includes a part of the frequencies in the frequency band. Multiple signals can be transmitted simultaneously via different channels of a frequency band, which can also be referred to as in-band carrier aggregation.

[0035] A carrier frequency (e.g., a center frequency of a frequency band / channel) can in each case be precisely assigned to a frequency band or channel. A carrier frequency and multiple sub-carrier frequencies can also be assigned to a frequency band or a channel.

[0036] For example, if the filtered signal power is greater than a predetermined threshold, it can be identified that the signal is being transmitted in a frequency band or a channel that includes the frequency of the reference signal or the frequency of the frequency band or channel (in particular the carrier frequency of the frequency band or channel) differs from the said frequency by no more than a predetermined amount.

[0037] One cut-off frequency of the low-pass filter that determines the bandwidth of the band-pass filter or multiple cut-off frequencies of the band-pass filter can be selected, in particular, in such a way that components of the mixed signal with a frequency higher than a predetermined amount are reduced.

[0038] In particular, the cut-off frequency can be selected in such a way that the sum component of the aforementioned sum is attenuated, in particular, with a required attenuation. In other words, the sum component of the mixed signal is filtered out.

[0039] In addition, the cut-off frequency can be selected in such a way that signal components of the difference component of the frequencies that are higher than a predetermined amount are attenuated, in particular, with the required attenuation.

[0040] When the magnitude of the difference between the frequency of the reference signal and the (carrier) frequency of the decoupled signal is greater than a predetermined amount, this causes the difference component to be attenuated. If the magnitude of the difference between the frequency of the reference signal and the (carrier) frequency of the decoupled signal is less than or equal to the predetermined amount, the difference component is not attenuated by the filter device or is attenuated by the filter device by no more than the predetermined amount. This causes, in particular, that only when the frequency of the reference signal corresponds to the frequency of the transmitted signal (in particular, the carrier frequency) or does not deviate from the frequency of the transmitted signal by more than a predetermined amount, the signal power of a difference component is greater than a predetermined threshold.

[0041] In other words, only when the deviation between the frequency of the reference signal and the (carrier) frequency of the decoupled signal is less than the predetermined amount, an output signal that is not attenuated or is attenuated very little in this way is provided by the filter device.

[0042] For example, one or more adjustable frequencies of the reference signal can be precisely assigned to different frequency bands or channels to be identified. If it is detected that the signal characteristics satisfy a specific criterion (for example, the signal power is greater than a predetermined threshold) for one of the adjustable frequencies or these adjustable frequencies, then the frequency band assigned to the adjustable frequency can subsequently be identified as the frequency band that is transmitting the transmitted signal or the channel assigned to the adjustable frequency can subsequently be identified as the channel that is transmitting the transmitted signal.

[0043] Of course, it is conceivable that after identifying a frequency band or a channel in which a signal is transmitted, a new identification of another frequency band or another channel in which another signal is transmitted is started. In this way, the different frequency bands used in an inter-band carrier aggregation can be advantageously identified.

[0044] The whole consisting of a device for providing a reference signal, a mixer, a filter device, and an evaluation device can also be referred to as a universal detector. The latter preferably performs a method according to the principle of a direct-conversion receiver. This method results in the reference signal and the decoupled signal being "mixed to zero", where the difference between the two signals is used as the mixing result. In particular, when a carrier component (component of the carrier frequency) of the reference signal and the decoupled signal has the same frequency, a signal formation of mixing to zero occurs. In this case, the frequency mixing of the VCO signal and the carrier component results in an output signal with a frequency of zero. The sidebands of the decoupled signal, especially the upper sideband, are converted to the baseband by the mixing. The decoupled signal here is a modulated signal with a carrier component, a baseband, and higher-order sidebands.

[0045] The output signal of the mixer usually contains a large number of mixing products, such as the sum frequencies of the reference signal and the decoupled signal, the harmonics of the two signals, and the difference and sum frequencies of higher-order frequencies. The filter device then easily separates the frequency of the baseband of the decoupled signal from the other components of the output signal. For this purpose, the first-order difference frequency or the highest frequency of the baseband of the decoupled signal is preferably used as the cut-off frequency of the filter device, whereby the mentioned other components (all components with higher frequencies) in the output signal of the mixer can be filtered out from the output signal.

[0046] As will be explained in more detail below, if the cut-off frequency is programmable, the latter can be selected in an application to determine the channel bandwidth of a transmitted signal within a mobile radio frequency band. It is also possible to determine multiple transmitted signals and their channel bandwidths within a frequency band (in-band). In particular, in the case of carrier aggregation in the uplink frequency range and the downlink frequency range, the detection of such multiple signals is desired.

[0047] The proposed method advantageously results in a reliable and rapid identification of a frequency band or a channel in which a signal is transmitted. For example, this information can be used to activate band-specific or channel-specific amplifier devices. This information can also be used to control a switching device for creating a signal path between the terminal device side interface and the antenna side interface, especially for adjusting a required signal path for transmission.

[0048] Furthermore, this advantageously achieves an improvement in the identification of a signal in a scenario of simultaneous transmission of a signal according to a TDD method and a signal according to an FDD method, since the signals transmitted according to these methods can be transmitted simultaneously on the same frequency band. In this case, accurate channel identification advantageously enables accurate identification of the signal type.

[0049] Furthermore, advantageously, in the case of in-band carrier aggregation, the signal power in each individual channel in which a signal is being transmitted can be determined, whereby on the one hand accurate identification of a channel can be carried out and, as will be explained in more detail below, subsequent monitoring of the channel can be carried out. In particular, in the case of said in-band carrier aggregation, the signal power transmitted in different channels of a single frequency band can also be reliably determined. This is particularly advantageous when one of the signals in the frequency band is transmitted to a distant base station while another signal in the same frequency band is transmitted to a less distant base station, whereby the powers can be of different magnitudes.

[0050] Furthermore, this advantageously enables the circuit device to be simply adapted to the standards used in different countries. For this purpose, the frequencies and cut-off frequencies of the country-specifically adjusted reference signals can be easily adjusted in the filter device by the control and evaluation device. These frequencies can be stored, for example, in a storage device of the control and evaluation device or in a storage device connected / connectable to the control and evaluation device.

[0051] Furthermore, advantageously, the circuit device can be designed to be adaptive. Thus, for example, during operation of the circuit device, it can be determined how often a frequency band or a channel is used by a dedicated frequency band or channel for signal transmission, where, at the start of the identification of a frequency band or channel, the most frequently used frequency band or channel is first checked for a transmitted signal. As a result, for example, the operation of the circuit device can be adapted to a specific terminal device, whereby the time period required to establish a desired signal transmission quality is shortened.

[0052] Furthermore, advantageously, a detector for determining signal characteristics only needs to be designed for operation within a predetermined frequency band range and thus does not need to be designed for operation over a large range, especially over the entire band range. This advantageously reduces the production costs of the circuit device.

[0053] In another embodiment, the circuit arrangement includes a device for determining a signal power of a filtered signal. This device may also be referred to as a power detector. In this case, the signal power can form one of the signal characteristics to be evaluated or one of the signal characteristics to be evaluated and in particular can be represented by a signal level. The device for determining the signal power may in particular include a rectifier or a rectifier and a comparator.

[0054] The device may generate an output signal, in particular a voltage signal, the amplitude of which represents the signal power / level. This can be done in particular on the basis of a characteristic curve, where the device has a device-specific input power / output voltage characteristic curve. Of course, an analog output signal can be digitized, for example by means of an A / D converter. This advantageously enables a simple and reliable determination of a signal characteristic and thus of a frequency band.

[0055] In another embodiment, a cut-off frequency of the filter device can be adjusted, in particular by the aforementioned control device. If the filter device is a band-pass filter, in particular the lower cut-off frequency and the upper cut-off frequency of the band-pass and thus the bandwidth and the center frequency can be adjusted. For example, a bandwidth of a band-pass filter (i.e., the width of the frequency range between the lower cut-off frequency and the upper cut-off frequency) can be 10 MHz. In particular, the cut-off frequencies of the band-pass filter can be selected in such a way that they include a frequency range of other components of the output signal containing the aforementioned difference component but no mixer. If the center frequency and the bandwidth of a band-pass filter are predefined, the reference frequency can be selected in such a way that the required difference component is filtered out of the output signal of the mixer.

[0056] By adjusting the cut-off frequency, the accuracy of the determination of the (carrier) frequency of the decoupled signal can be advantageously adjusted. The lower the cut-off frequency, the smaller the deviation between the adjusted frequency of the reference signal and the (carrier) frequency of the decoupled signal, so that the difference component is provided by the filter device with a level higher than a predefined threshold. In other words, if the difference component (i.e., the filtered signal) has a level higher than a predefined threshold, the cut-off frequency determines how much the frequencies mentioned differ.

[0057] In particular, the identification of frequency bands with different sensitivities can thus be carried out. For example, if a more precise determination of the (carrier) frequency is subsequently required, for example in order to identify a channel in a frequency band, the cut-off frequency of the filter device can be reduced, for example to a predefined value.

[0058] If it is desired to identify a channel in which a signal is being transmitted, it may be necessary to increase the determination accuracy of the (carrier) frequency, where this can be done by reducing the cut-off frequency of the filter device. For example, in a frequency band identification step, the cut-off frequency of the filter device can be adjusted to a first value. The first value can be selected in particular in such a way that the cut-off frequency corresponds to the frequency band with the largest bandwidth to be identified.

[0059] In addition, the different frequencies of the reference signal (e.g., the center frequency of a frequency band in which a signal can be transmitted) can be adjusted in the band identification step. Such a center frequency can be a frequency assigned to the frequency band to be identified. If the signal power of the filtered signal is detected to be greater than a predetermined threshold for one of these adjusted frequencies, the frequency band assigned to the currently adjusted frequency of the reference signal can be identified as a frequency band in which a signal is being transmitted. In addition, in a channel identification step, a cut-off frequency of the filter device can be adjusted to a second value that is smaller than the first value, in particular smaller than the bandwidth of the identified frequency band. In addition, the different frequencies of the reference signal can be adjusted in the channel identification step, and these frequencies are within the identified frequency band. For example, it is conceivable that one frequency (e.g., a center frequency) or multiple frequencies are precisely assigned to respective channels in a frequency band. These frequencies or their selection can then be adjusted in the channel identification step. If the signal power of the filtered signal is subsequently detected to be greater than a predetermined threshold for one of these adjusted frequencies, the channel assigned to the currently adjusted frequency of the reference signal can be identified as a channel in which a signal is being transmitted.

[0060] Of course, it is conceivable that after identifying a channel in which a signal is being transmitted, a new identification of another frequency band or another channel in which another signal is being transmitted is started. In this way, the different channels or frequency bands used in in-band or inter-band carrier aggregation can be advantageously identified.

[0061] If the different frequencies of the reference signal are adjusted for identification purposes, the different frequencies of the reference signal can be adjusted for a predetermined time period (e.g., 50 μs), and then the next successive frequency is adjusted. The predetermined time period can be adjusted as described above for the time period for determining signal characteristics.

[0062] The adjustability of the cut-off frequency advantageously enables the identification of a frequency band or a channel with adjustable accuracy.

[0063] In another embodiment, the means for providing a reference signal includes a phase-locked loop or is designed as a phase-locked loop. A phase-locked loop may represent an electronic circuit arrangement that, via a closed control loop, affects the phase of a variable oscillator and the associated frequency in such a way that the phase deviation between an external reference signal and an oscillator or a signal originating from the oscillator is as constant as possible. The structure of a phase-locked loop is known to those skilled in the art. In particular, a phase-locked loop may include a phase comparator, a loop filter, and a voltage-controlled oscillator. Additionally, a phase-locked loop may include one or more frequency dividers. An input signal of the phase-locked loop may in particular be a sinusoidal signal of a predetermined frequency or a sinusoidal signal divided by a frequency divider having a predetermined division factor. In this case, the sinusoidal signal is generated by a corresponding generating device (such as an oscillator, in particular a quartz oscillator). For example, the control device may include such a generating device.

[0064] Additionally, the division factor of a frequency divider for the sinusoidal signal can also be adjusted by the control device. Additionally, the division factor of a frequency divider for a feedback output signal of the voltage-controlled oscillator can also be adjusted by the control device. The desired frequency of the reference signal corresponding to the output signal of the voltage-controlled oscillator can thus be adjusted in particular by means of these two division factors.

[0065] This advantageously enables the generation of the reference signal to be easily achieved, reliable, and also precise.

[0066] In another embodiment, the circuit arrangement includes at least one control device for adjusting the frequency of the reference signal and / or for adjusting the cut-off frequency of a filter device. This and the corresponding advantages have been explained above.

[0067] In another embodiment, the circuit arrangement includes at least one device for signal transmission detection. By means of this device for signal transmission detection, it can be detected whether one or more uplink signals or downlink signals are being transmitted via the circuit arrangement. The device for signal transmission detection can be coupled in a signal-technical manner to a signal path for transmitting an uplink signal and / or a downlink signal, in particular via another signal coupler of the circuit arrangement. However, alternatively, a galvanic connection can also be provided between the signal path and the device for signal transmission detection.

[0068] The device for detecting signal transmission can in particular perform a band-nonspecific detection of a signal transmission. In other words, it can be detected whether a signal is being transmitted via the circuit arrangement, where, however, no frequency band is taken into account for this transmission.

[0069] If the device for signal transmission detection detects that a signal is being transmitted via the circuit arrangement, the identification of the frequency band or channel in which the signal is being transmitted can be started. In particular, the device for signal transmission detection can generate a start signal for starting this identification. The device for signal transmission detection can be formed at least in part by the evaluation device. Additionally, the device can include at least one rectifier or a rectifier and at least one comparator.

[0070] This advantageously achieves that an identification is only carried out when a signal is actually being transmitted via the circuit arrangement. In this way, the energy consumption and computing power of the provided circuit arrangement can be reduced.

[0071] In another embodiment, the circuit arrangement includes at least one switching element. The switching element can be designed as a switch, for example, a SPDT (single-pole double-throw) switching element. In a first switching state of the switching element, a first port of the signal coupler is connected to the mixer, and in another switching state of the switching element, the other port of the signal coupler is connected to the mixer, in particular to the input port of the mixer. Thus, it can be advantageously easily and reliably determined whether an uplink signal or a downlink signal is being transmitted via the circuit arrangement.

[0072] The different ports of the signal coupler can be isolated from each other by more than a predetermined amount. For example, if an uplink signal is transmitted via a signal path of the circuit arrangement and decoupled from this signal path by the signal coupler, the signal power of the decoupled signal provided at the first port of the signal coupler can be greater than the signal power of the signal provided at the other port. If a downlink signal is transmitted via this signal path, the signal power of the signal provided at the other port can correspondingly be greater than the signal power of the signal provided at the first port.

[0073] For example, by changing the switching state, it can be detected whether an uplink signal or a downlink signal is being transmitted. For example, if the signal power of a filtered signal is detected to be greater than a predetermined threshold, the switching state of the switching element can be changed. Depending on the output switching state, if the signal power of the filtered signal increases or decreases, an uplink signal can be detected. If the signal power of the filtered signal decreases or increases, a downlink signal can be detected. This detection can be carried out before a band identification step in this case, and also during a band identification step.

[0074] Additionally, the identification of the frequency band or a channel in which a signal is being transmitted can be performed as a function of information as to whether the signal being transmitted is an uplink signal or a downlink signal. For example, if an uplink signal is detected, the frequency of the reference signal can be adjusted to the frequency of the frequency band or channel allocated for transmitting the uplink signal during the band identification step or the channel identification step. Correspondingly, if a downlink signal is detected, the frequency of the reference signal can be adjusted to the frequency of the frequency band or channel allocated for transmitting the downlink signal during the band identification step or the channel identification step.

[0075] This advantageously enables faster identification of the frequency band or a channel in which a signal is being transmitted.

[0076] In another embodiment, the circuit arrangement includes a bypass device, wherein a signal is transmitted between the signal coupler and the mixer via the bypass device. The bypass device can include a bypass switching element, for example, the bypass switching element can be designed as a switch. In a first switching state of the switching element, the signal can be transmitted without attenuation or amplification. In another switching state, the signal can be transmitted with a predetermined, especially adjustable, amplification or attenuation. In this case, the bypass device can include a corresponding amplifier device or attenuator device.

[0077] As a result, the reliability of the identification can be advantageously increased, namely especially by amplification of weakly decoupled signals. The operational reliability during identification can also be advantageously increased, namely especially by attenuation of overly strong decoupled signals. In particular, the amplification by the amplifier device or attenuator device of the bypass device can extend the voltage / power characteristics of the device mentioned for determining the signal power of the filtered signal. This extension can be necessary, especially due to the dynamics of the transmitted signal, to be able to reliably process different level ranges.

[0078] In another embodiment, at least one channel in which the transmitted signal is being transmitted can be additionally identified as a function of the adjusted frequency and the at least one signal characteristic. This and the corresponding advantages have been explained above.

[0079] In another embodiment, the channel can be additionally identified as a function of the adjusted cut-off frequency. This and the corresponding advantages have been explained above.

[0080] In another embodiment, a channel bandwidth of a channel can be determined as a function of a plurality of adjusted frequencies and at least one signal characteristic.

[0081] This and the corresponding advantages will be explained in more detail below.

[0082] There is also proposed a method for identifying a frequency band in which an uplink signal or a downlink signal is being transmitted, wherein a decoupled uplink signal or a downlink signal is provided or the corresponding signal is decoupled. The signal is especially decoupled from a signal path of the circuit arrangement. Additionally, at least one reference signal of a predetermined frequency is provided, especially by means of a device for providing a reference signal. Additionally, the decoupled signal and the reference signal are mixed, especially by the mixer. Additionally, the mixed signal is filtered, especially by the filter device. Additionally, at least one signal characteristic of the filtered signal is determined, especially by means of the evaluation device or a device for determining a signal characteristic. In particular, a level of the filtered signal can be determined. Additionally, a frequency band or a channel in which the signal being transmitted is being transmitted is determined as a function of the frequency of the reference signal and at least one signal characteristic of the filtered signal.

[0083] The method can hereby be carried out by means of a device according to any one of the embodiments disclosed in the present disclosure. The device is hereby especially configured in such a way that a method according to any one of the embodiments described in the present disclosure can be carried out by the device.

[0084] For example, a signal power of the filtered signal can be determined and the frequency band to which the adjusted frequency of the reference signal is assigned can be identified as a frequency band in which the signal is transmitted.

[0085] In the method, different frequencies of the reference signal are adjusted one after the other, especially the device for generating the reference signal is correspondingly operated / controlled. In this case, especially the different frequencies of the reference signal can be adjusted in such a way that the difference between them is greater than or precisely a predetermined minimum amount, wherein the minimum amount can be, for example, 200 kHz. For each of these adjusted frequencies, the signal power of the filtered signal can subsequently be determined, wherein a frequency band in which a signal is being transmitted can only be identified if the signal characteristic of an adjusted frequency of the reference signal assigned to a frequency band meets a predetermined criterion (for example, the signal power of an adjusted frequency of the reference signal assigned to a frequency band exceeds a predetermined threshold). Of course, it is conceivable that multiple frequency bands in which the signal is being transmitted are identified. For this purpose, for example, the method can be restarted after the identification of a frequency band, but wherein other frequencies of the reference signal are subsequently adjusted.

[0086] In this case, there may be an assignment, in particular a predefined assignment, between the adjustable frequency and the frequency band of the reference signal for identification purposes. There may also be an assignment between the adjustable frequency of the reference signal and the channels of the frequency band, which, as will be explained in more detail below, can be used to identify a channel. If a frequency band or a channel in which a signal is being transmitted has been identified, the corresponding adjusted frequency of the reference signal and the detected signal power (if applicable) can be stored, for example, in a memory device. In this case, the memory device can be a memory device of the control and evaluation device. This enables the correspondingly stored frequencies of the reference signal to be easily retrieved and adjusted for a later check or monitoring as to whether a signal is still being transmitted in the frequency band or channel.

[0087] In another embodiment, frequency-range-specific or channel-specific reference signals of different frequencies are generated, where, in each case, the reference signal is mixed with the decoupled signal, the mixed signal is filtered, and at least one signal characteristic of the mixed signal is determined, where the frequency band or the channel is determined as a function of the frequency-range-specific or channel-specific signal characteristic. This and the corresponding advantages have been explained above.

[0088] In another embodiment, at least one cut-off frequency of a filter device is changed. This and the corresponding advantages have been explained above.

[0089] For example, both the frequency of the reference signal and the cut-off frequency can be changed. For example, if the frequency of the reference signal assigned to the frequency band is adjusted, the cut-off frequency can be adjusted to a frequency-band-specific cut-off frequency. For this purpose, there may be a previously known assignment between a frequency band and a cut-off frequency.

[0090] In particular, if a frequency band has been identified and a channel identification of a channel of the identified frequency band is to be carried out subsequently, where the identified frequency band includes a plurality of channels, the cut-off frequency can be changed, more particularly reduced. In the case of channel identification, the predefined frequency of the reference signal, in particular the channel-specific frequency, can also be adjusted. Additionally, the predefined cut-off frequency (for example, the channel-specific cut-off frequency) can also be adjusted. For example, if a frequency band in which a signal is being transmitted has been identified, the frequency of the reference signal for channel identification can subsequently be adjusted only to the frequency of the frequency band. As explained above, these frequencies adjusted for channel identification can differ from each other by a predefined minimum amount or more than the predefined minimum amount.

[0091] Additionally, it is conceivable that for identifying a channel, multiple runs of the method can be executed, in which the aforementioned minimum amount and / or cut-off frequency will decrease in successive runs.

[0092] In one run, the set of frequencies of the reference signal to be adjusted can also be determined depending on the cut-off frequency used in the previous run. For example, in a channel identification run, the multiple frequencies can only be adjusted from a frequency band that includes the frequency of the reference signal as the center frequency, the frequency of the reference signal having been adjusted in the previous run and detected for a transmitted signal, wherein the bandwidth of the frequency band corresponds to or is determined as a function of the cut-off frequency in the previous run.

[0093] However, generally speaking, various strategies for adjusting the frequency of the reference signal and for adjusting the cut-off frequency of the filter device are conceivable to identify in a desired manner one or more frequency bands and / or one or more channels in which a signal is being transmitted.

[0094] In another embodiment, a frequency band is identified, and then a channel of the frequency band is identified. This and the corresponding advantages have been explained above.

[0095] In particular, in order to identify a frequency band in which a signal is being transmitted, the band identification frequency and the band identification cut-off frequency (if applicable) of the filter device can be adjusted. For example, a band identification cut-off frequency can be 60 MHz. Here it can be assumed that multiple frequency bands have multiple fixed and predetermined bandwidths. Of course, other cut-off frequencies can also be adjusted, for example as a function of multiple bandwidths that can be obtained from a frequency band table of a mobile radio.

[0096] For channel identification, the channel identification frequency and the channel identification cut-off frequency (if applicable) of the filter device can be adjusted in a corresponding manner. For example, a channel identification cut-off frequency can be 200 kHz. Here, it can be assumed that multiple channels can have different bandwidths, for example, 1.4 MHz, 5 MHz or 10 MHz. Of course, however, other cut-off frequencies can also be adjusted, for example as a function of multiple bandwidths that can be obtained from a frequency channel table of a mobile radio.

[0097] Here, the channel identification frequency and the channel identification cut-off frequency (if applicable) can be band-specific. This can mean that for different frequency bands in which a signal is being transmitted, dedicated predetermined channel identification frequencies and different channel identification cut-off frequencies (if applicable) are adjusted in each case.

[0098] In another embodiment, the channel bandwidth of the channel is determined.

[0099] For example, if a frequency band has been identified, a channel and / or a channel bandwidth can be identified by successively adjusting all of the segmented frequencies and a segmented cut-off frequency from a set of segmented frequencies of the identified frequency band and then determining at least one signal characteristic of the filtered signal for each adjusted segmented frequency. The segmented cut-off frequency of the filter device defines a bandwidth of a segment herein. In other words, the frequency band can be divided into a plurality of segments, and the plurality of segments are then individually examined for the transmission of a signal. A segmented or quantized frequency band is thus examined. This examination can also be referred to as a grid examination.

[0100] In particular, the segmented frequencies starting from the band start frequency can be incremented step by step, for example, with a predetermined frequency increment until the band end frequency of the segmented frequencies, wherein in each step, at least one signal characteristic of the filtered signal is then determined for the corresponding segment. For example, the predetermined frequency increment can be 200 kHz. The segment cut-off frequency preferably corresponds to this frequency increment.

[0101] If the signal characteristic meets a predetermined criterion, for example, if the signal power is greater than a predetermined threshold, the corresponding segment can be identified as a segment in which a signal is being transmitted. If the criterion is only met for a single segment and not for adjacent segments, the channel can be identified as that segment and the channel bandwidth is identified as the segment bandwidth.

[0102] If the signal characteristic meets the predetermined criterion for a plurality of adjacent segments, the channel can be identified as the totality of the plurality of segments and the channel bandwidth is identified as the sum of all the segment bandwidths of these adjacent segments.

[0103] Thus, for example, in the case of in-band carrier aggregation, a plurality of channels and a plurality of corresponding channel bandwidths in the frequency band can be identified.

[0104] In other words, by adjusting the segmented cut-off frequency or bandwidth of a low-pass filter device and also the center frequency of a band-pass filter device, the bandwidth of the decoupled signal can be quantized, that is, divided into a plurality of segments. The lower the segmented cut-off frequency, the more precisely the channel bandwidth can be determined. The lowest segment cut-off frequency that can be adjusted and that can be, for example, 200 kHz can thus determine the channel bandwidth most precisely. In the case of a segmented cut-off frequency of 200 kHz, one segment is within the channel spacing of mobile radio. Other, especially higher, segmented cut-off frequencies result in different quantization and thus different accuracies.

[0105] This advantageously enables simple and rapid identification of a channel and / or a channel bandwidth.

[0106] In another embodiment, after identifying a frequency band or a channel in which a signal is being transmitted, monitoring of at least one signal characteristic of the transmitted signal is performed. This signal characteristic can be, for example, the signal power of the corresponding filtered signal. For example, the detected frequency for the frequency band to be monitored can be adjusted continuously or at predetermined time intervals, especially regularly, along with the frequency of the reference signal. Additionally, the signal power of the filtered signal can be determined, where a continuous transmission of the signal can be detected when the signal power is greater than a predetermined threshold or greater than another predetermined threshold. Additionally, if the signal power is below a predetermined threshold or another predetermined threshold, termination or interruption of the signal transmission can be detected. For example, if a termination or interruption of the signal transmission is detected, the amplifier device of the circuit arrangement can be correspondingly controlled, for example deactivated. The signal path for the transmission of the signal can even be disconnected. The monitoring can also be referred to as a monitoring mode. The monitoring advantageously achieves an improved operation of the circuit arrangement, especially since the operation (such as the operation of the amplifier device and / or the creation of the transmission signal path) can be adapted to the current transmission state.

[0107] Alternatively or cumulatively, the identification of another frequency band or a channel or another channel is initiated. This can also be referred to as a scanning mode.

[0108] The identification of another frequency band or another channel advantageously achieves an improved operation of the circuit arrangement, that is, the operation is adapted to the transmission of multiple signals. The identification of a channel advantageously achieves a more precise determination of the frequency range in which a signal is being transmitted, and thereby also adapts the operation of the circuit arrangement thereto.

[0109] In another embodiment, the monitoring and identification of another frequency band or (another) channel are performed sequentially or simultaneously. In other words, the circuit arrangement can operate alternately in a monitoring mode and an identification mode. This advantageously achieves an improvement in adapting the operation to the current transmission state.

[0110] However, if the circuit arrangement includes suitable means for performing monitoring and identification simultaneously, for example, a monitoring and a detection part as explained in more detail below, the monitoring and identification of another frequency band or (another) channel can be performed simultaneously. This advantageously enables faster identification. Description of the Drawings

[0111] The present invention is explained in more detail with reference to exemplary embodiments. Shown in the figures are:

[0112] Figure 1 is a schematic block diagram of a circuit arrangement according to the present invention,

[0113] Figure 2 is a schematic block diagram of a circuit arrangement in another embodiment according to the present invention,

[0114] Figure 3 is a schematic block diagram of a circuit device in another embodiment according to the present invention,

[0115] Figure 3a is a schematic block diagram of a circuit device in another embodiment according to the present invention,

[0116] Figure 4 is a schematic block diagram of a device for generating a reference signal,

[0117] Figure 5 is a schematic representation of a plurality of frequency ranges,

[0118] Figure 6 is a schematic representation of a frequency range having a plurality of channels,

[0119] Figure 7 is a schematic flow chart of a method according to the present invention, and

[0120] Figure 8 is a schematic flow chart of a method in another embodiment according to the present invention. DETAILED DESCRIPTION

[0121] In the following, the same reference numerals denote the same or similar technical features.

[0122] Figure 1 FIG. shows a schematic block diagram of a circuit device 1 according to the present invention. For example, a terminal device 2 of a mobile phone is shown. The circuit device 1 includes a terminal device side interface 3, wherein signals can be transmitted between the terminal device 2 and the circuit device 1 by means of the terminal device side interface 3. The terminal device side interface 3 can include or form a wireless coupler. The circuit device 1 further includes an antenna side interface 4, wherein signals can be transmitted between the antenna 5 and the circuit device 1 by means of the antenna side interface 4.

[0123] In particular, so-called uplink signals can be transmitted from the terminal device 2 to the antenna 5 via the circuit device 1. This transmission can be initiated by the terminal device 2 itself or can be requested by a base station. Additionally, so-called downlink signals can be received from the antenna 5 and then transmitted to the terminal device 2 via the circuit device 1.

[0124] The circuit device further includes an attenuation device 6. This device can preferably be an attenuation device 6 having an adjustable attenuation factor. Additionally, the circuit device 1 includes a control and evaluation device 7, which can for example be designed as a microcontroller or include such a microcontroller.

[0125] A signal line and a processing section 8 of the circuit device 1 are schematically shown. The section 8 may include a device for amplifying a signal transmitted via the circuit device 1, a switching device for creating a signal path for transmitting an uplink signal or a downlink signal, and also a filter device in the form of, in particular, multiplexers. Of course, the section 8 may also include other devices.

[0126] In addition, the circuit device 1 includes a signal coupler 9, and a signal can be decoupled from a signal path between the terminal device side interface 3 and the attenuation device 6 by means of the signal coupler 9. Of course, the signal coupler 9 may also be arranged at other positions of the circuit device 1 and decouple the uplink signal or the downlink signal accordingly.

[0127] The signal coupler 9 has a first antenna side port 9a and a second terminal device side port 9b. The signal coupler 9 can in particular be a direction-sensitive signal coupler. Due to this direction sensitivity, the power of a signal decoupled at a first port (such as an antenna side port) of the signal coupler can be greater than the power of a signal of the same signal strength decoupled at a second port (such as a terminal device side port) of the signal coupler.

[0128] In addition, the circuit device 1 includes a switching element 10, and the switching element 10 can be designed as a switch. The switching element 10 can assume various switching states. In this case, the ports 9a, 9b of the signal coupler 9 are connected to different input ports of the switching element 10. An output port of the switching element 10 is connected to an input port of a bypass device 11 of the circuit device 1. The bypass device 11 includes a disconector element 12 and an amplifier device 13, wherein the disconector element 12 and the amplifier device 13 are connected in parallel. If the disconector element 12 assumes a closed state, a signal is transmitted from the input port of the bypass device 11 to the output port of the bypass device 11 without amplification. If the disconector element 12 assumes an open state, the signal transmitted between the two ports of the bypass device 11 is amplified by the amplifier device 13. The disconector element 12 can be designed as a single-pole switch that can assume a closed or a disconnected state.

[0129] It is conceivable that, alternatively, the bypass device 11 includes two switching elements, wherein the output port of the bypass device 11 is connected to the output port of the amplifier device 13 via a first switching element and the input port of the bypass device 11 is connected to the input port of the amplifier device 13 via another switching element. If adjusted to a first switching state of the two switching elements, a signal is transmitted from the input port of the bypass device 11 to the output port of the bypass device 11 without amplification (i.e., via a signal path arranged in parallel with the amplifier device 13). If adjusted to a second switching state of the two switching elements, a signal is transmitted from the input port of the bypass device 11 to the output port of the bypass device 11 via the amplifier device 13.

[0130] Furthermore, the circuit arrangement 1 includes a mixer 14, wherein a first input port of the mixer 14 is connected to the output port of the bypass device 11 and another input port of the mixer 14 is connected to a device 15 for generating a reference signal. As will be described later, especially with reference to Figure 4 the embodiment shown in, the device 15 may include or form a phase-locked loop.

[0131] In this case, the reference signal is a tunable frequency, especially a harmonic signal, especially a sinusoidal signal. The circuit arrangement 1 hereby includes the device 15 for generating the reference signal.

[0132] An output port of the mixer 14 is connected to a filter device 16, which is used for low-pass filtering of the mixed signals present at the output port of the mixer 14. The filter device 16 is hereby a filter device with an adjustable cut-off frequency.

[0133] Furthermore, the circuit arrangement 1 includes a device 17 for determining the signal power of the filtered signal provided by the filter device 16. Not shown is an A / D converter, which can digitize an output signal of the device 17, wherein the A / D converter can be part of the control and evaluation device 7.

[0134] It is also shown that the control and evaluation device 7 adjusts the switching state of the switching element 10, especially the switching element 10. It is also shown that the control and evaluation device 7 controls an operation, especially a state, of the bypass device 11. Furthermore, the control and evaluation device 7 can adjust a cut-off frequency of the filter device 16. Similarly, the device 15 for generating a reference signal can be controlled by the control and evaluation device 7 in such a way that a desired frequency of the reference signal is adjusted.

[0135] Furthermore, the signal power of the filtered signal can be evaluated by the control and evaluation device 7, in particular compared with a predefined threshold value.

[0136] As will be explained in more detail below, a predefined frequency of the reference signal is adjusted in such a way. Furthermore, the reference signal is then mixed with the decoupled signal. The mixed signal is then filtered, wherein the level of the filtered signal is determined. Furthermore, as a function of the adjusted frequency and the signal power of the reference signal, a frequency band FB1, FB2, FB3 (see Figure 5 ) in which an uplink signal or a downlink signal is being transmitted is identified.

[0137] Furthermore, it can also be identified whether an uplink signal or a downlink signal is being transmitted via the circuit arrangement 1. For example, if it is detected that the signal power of the filtered signal is greater than a predefined threshold value, the switching state of the switching element 10 can be changed. For example, if the switching state is changed in such a way that the antenna-side input port of the switching element 10 is no longer connected to the output port of the switching element 10 but to the terminal device-side input port and the signal power of the filtered signal increases, it can be identified that an uplink signal is being transmitted. If the signal power decreases, it can be identified that a downlink signal is being transmitted. For example, if the switching state is changed in such a way that the terminal device-side input port of the switching element 10 is no longer connected to the output port of the switching element 10 but to the antenna-side input port and the signal power of the filtered signal increases, it can be identified that a downlink signal is being transmitted. If the signal power decreases, it can be identified that an uplink signal is being transmitted.

[0138] If an excessive signal power is detected in an open state of the isolator element 12, the isolator element 12 can be adjusted to a closed state, in particular in order to avoid a load on these components due to the excessive signal power and an overdrive of the amplifier device that would lead to the formation of undesired harmonics.

[0139] It is also shown that the control and evaluation device 7 controls the operation, in particular a state, of the section 8, for example by activating / deactivating the amplifier device and by adjusting the switching state of the switching elements of the signal line and the processing section 8. The operation of the signal line and the processing section 8 can be controlled, for example, as a function of the identified frequency bands FB1, FB2, FB3.

[0140] Figure 2 A schematic block diagram of a circuit arrangement 1 in another embodiment according to the invention is shown. In this case, Figure 2 the circuit arrangement 1 shown is designed to cooperate withFigure 1 The circuit arrangement 1 shown is basically the same, so reference is made to the corresponding description. Compared with Figure 1 the circuit arrangement 1 shown, Figure 2 the embodiment shown includes a device for signal transmission detection. The device includes another signal coupler 18, and a signal is decoupled from a signal path between the terminal device side interface 3 and the attenuation device 6 by means of the another signal coupler 18. The signal coupler 18 can be designed as a directional coupler that decouples a (small) part of the signal power of the signal from the signal path. In this case, a first output port of the another signal coupler 18 is connected to a reference potential, especially a ground potential, via a resistance element 19. The resistance element 19 forms a matching resistor and can have a predetermined resistance value, such as 50 ohms. Another output port of the another signal coupler 18 is connected to a detector device 21, for example, via an amplifier device (not shown). The detector device 21 determines a signal power, especially by generating a voltage signal whose amplitude is proportional to a signal power to determine the signal power. The output signal representing the signal power is then transmitted to a comparator device 22. A reference voltage Vref forming a comparison threshold of the comparator device 22 is selected in such a way that the noise power of the detector device 21 does not cause the comparator device 22 to generate a detection signal. The sensitivity of the detection of a signal transmission depends on the level of the reference voltage Vref. The closer the reference voltage Vref is to a voltage representing the noise power and generated by the detector device 21, the weaker the signal that can be detected. If the output signal representing the signal power and generated by the detector device 21 is equal to or greater than the reference voltage Vref, the comparator device 22 generates a detection signal and transmits the detection signal to the evaluation device 7.

[0141] If such a detection signal is detected by the control and evaluation device 7, a signal transmission via the circuit arrangement 1 is detected. In particular, it is thus detected whether a signal is being transmitted via the circuit arrangement 1, where the detection is performed independently of the frequency bands FB1, FB2, FB3 (see Figure 5 ). In other words, a frequency-band-independent detection of a signal transmission is performed. If it is detected that a signal is being transmitted, the identification of a frequency band FB1, FB2, FB3 or the identification of a channel K1,..., K6 can be initiated by the control and evaluation device 7, especially by generating a reference signal.

[0142] The circuit device may include another comparator device (not shown), and the output signal of the comparator device 21 can also be compared with a predetermined protection signal level by means of this another comparator device. The protection signal level can be provided in the form of another reference voltage (not shown), wherein this another comparator device compares the level of the output signal with the protection signal level. In this case, if the signal power is greater than the predetermined protection signal power, a protection signal is generated. The protection signal can be used to control the attenuation device 6 and for this purpose can be transmitted to the evaluation device 7. In particular, when the protection signal has been generated, the attenuation factor of the attenuation device 6 can be increased. As a result, a load on the circuit device 1 due to excessive signal power can be prevented. The predetermined protection signal power can be greater than the starting signal power.

[0143] Figure 3 FIG. shows a schematic block diagram of a circuit device 1 in another embodiment according to the present invention. In this case, Figure 3 The shown circuit device 1 is designed to be Figure 2 substantially the same as the shown circuit device 1, and thus reference is made to the corresponding description. Different from Figure 2 the shown circuit device 1, Figure 3 the shown embodiment does not include a switching element 10 for connecting the signal coupler 9 to the bypass device 11.

[0144] Different from Figure 2 the shown embodiment, the circuit device 1 includes another signal coupler 9a, which can also be designed as a directional coupler, another bypass device 11a, another mixer 14a, another filter device 16a, another device 17a for determining the signal power, and another device 15a for generating another reference signal.

[0145] In this case, the sum of the signal coupler 9, the bypass device 11, the mixer 14, the filter device 16, the device 17 for determining the signal power, and the device 15 for generating a reference signal forms a detection part of the circuit device 1.

[0146] The sum of another signal coupler 9a, another bypass device, another mixer 14a, another filter device 16a, another device 17a for determining the signal power, and another device 15a for generating a reference signal forms a monitoring part of the circuit device 1.

[0147] In this case, as far as the circuit is concerned, the detection section is designed to be the same as the monitoring section. However, the isolation characteristics of the different ports of the previously explained signal coupler 9 for the antenna-side port and the terminal device-side port can be different, especially opposite, from those of another signal coupler 9a. In other words, the signal couplers 9, 9a have different directional sensitivities.

[0148] The presence of a detection section and a monitoring section advantageously enables the simultaneous identification of the frequency bands FB1, FB2, FB3 in which signals are being transmitted or the channels K1, ..., K6 of the frequency bands FB1, FB2, FB3, for example by adjusting the different frequencies of the reference signals and the cut-off frequencies of the filter device 16. At the same time, an identified frequency band FB1, FB2, FB3 or an identified channel K1, ..., K6 can continue to be monitored, for example by continuously or periodically determining the signal power of the signals being transmitted in the identified frequency band FB1, FB2, FB3 or channel K1, ..., K6.

[0149] In particular, part 8 of the circuit arrangement 1 can also be controlled as a function of the monitoring result. For example, if it is detected that the output signal of another device 17a drops below a predetermined threshold, it can be detected that no signal transmission is taking place in the corresponding frequency band FB1, FB2, FB3 or channel K1, ..., K6. Then, for example, the corresponding activated amplifier device of part 8 can be deactivated.

[0150] In addition, Figure 3 the illustrated circuit arrangement can also be used to identify whether an uplink signal or a downlink signal is being transmitted via the circuit arrangement 1. For example, if the control and evaluation device 7 detects that the power determined by the device 17 of the detection section is lower than the power determined by the device 17a of the monitoring section, it can be identified that an uplink signal is being transmitted. For example, if the control and evaluation device 7 detects that the power determined by the device 17 of the detection section is higher than the power determined by the device 17a of the monitoring section, it can be identified that a downlink signal is being transmitted. For this purpose, it may be necessary to adjust the two reference signals generated by the devices 15, 15a to the same frequency.

[0151] Figure 3a Fig. shows a schematic block diagram of a circuit arrangement 1 in another embodiment according to the invention. In this case, Figure 3a the circuit arrangement 1 shown is designed to be substantially the same as the circuit arrangement 1 shown in Figure 3 and reference is made to the corresponding description. Different from the circuit arrangement 1 shown in Figure 3 the circuit arrangement 1 shown Figure 3aThe illustrated embodiment does not include another device 15a for generating another reference signal. Instead, the reference signal generated by the device 15 for generating the reference signal is transmitted to the mixer 14 and another mixer 14a.

[0152] In this embodiment, the frequencies of the reference signals supplied to the mixers 14, 14a cannot be adjusted independently of each other. Therefore, the frequency adjustment for a monitoring performed using the monitoring section shown here cannot be Figure 3 as independent as in the illustrated embodiment for the frequency adjustment of a detection performed using the detection section shown here. However, for the embodiment as Figure 3a shown, as explained for the embodiment as Figure 3 shown, it is possible to identify whether an uplink signal or a downlink signal is being transmitted via the circuit arrangement 1. This is particularly advantageous for signals transmitted according to the TDD mode, since in this mode, the uplink signal and the downlink signal can have the same frequency. Using the part of the circuit arrangement 1 that includes another signal coupler 9a, another bypass device 11a, another mixer 14a, another filter device 16a, and another device 17a for determining the signal power, a reliable analysis of the uplink signals reliably decoupled by the other signal coupler 9 can be performed, where these uplink signals are in particular not superimposed by overly strong downlink signals. Accordingly, using the part of the circuit arrangement 1 that includes the signal coupler 9, the bypass device 11, the mixer 14, the filter device 16, and the device 17 for determining the signal power, a reliable analysis of the downlink signals reliably decoupled by the signal coupler 9 can be performed, where these downlink signals are in particular not superimposed by overly strong uplink signals.

[0153] Figure 4A schematic block diagram showing a device 15, 15a for generating a reference signal is presented. The devices 15, 15a are designed here as a phase-locked loop. The latter includes a controllable oscillator 25 that generates a reference signal as an output signal. The output signal of the oscillator 25 is supplied to a frequency divider 26. A dividing factor n of the frequency divider 26 can be adjusted by a control and evaluation device 7. An output signal of the frequency divider 26 is supplied to a phase comparator 27. Another input signal of the phase comparator 27 is provided by another frequency divider 28, where a dividing factor m of the other frequency divider 28 can likewise be adjusted by the control and evaluation device 7. The input signal of the other frequency divider 28 is here an oscillation signal, in particular a sinusoidal signal, that can be generated by a corresponding signal source, in particular a quartz oscillator 23. In this case, the signal source can form part of the control and evaluation device 7 or can even be separated from the control and evaluation device 7. An output signal of the phase comparator 27 is supplied to a loop filter 29, and the output signal of the loop filter 29 in turn adjusts the controllable oscillator 25, in particular the capacitance of a varactor diode.

[0154] The dividing factors of the frequency dividers 26, 28 can be adjusted by the control and evaluation device 7 in such a way that respective (mobile) radio frequencies can be generated in a channel spacing, where a spacing width can be, for example, 200 kHz, i.e., adjacent frequencies have a frequency spacing of 200 kHz between each other.

[0155] Frequency bands FB1, FB2, FB3 or channels K1,..., K6 (see Figure 5 and Figure 6 ) that can be used for signal transmission and that can also be referred to as effective bands or channels, or the frequencies assigned to these bands or channels, can be stored in the control and evaluation device 7. These frequencies can subsequently be adjusted by adjusting the said dividing factors.

[0156] The available frequency bands FB1, FB2, FB3 or channels K1, ..., K6 can be region-specific bands or channels. The different frequencies of the available frequency bands FB1, FB2, FB3 or channels K1, ..., K6 can thus be stored for different regions or countries. For example, the regions can be North America, China, South America, and Europe. The proposed device can thus be used in different regions, where, for use in a specific region, the frequencies of the corresponding region-specific band or channel for signal transmission are stored in the control and evaluation device 7, in particular via a suitable interface such as a CAN bus interface in the control and evaluation device 7. In principle, any desired combination of frequencies can be stored in the control and evaluation device 7. The frequencies of the corresponding region-specific band or channel for signal transmission can thus be programmed in the control and evaluation device 7 via the CAN bus. If the region is excluded, reprogramming can be carried out in a corresponding manner.

[0157] Figure 5 A schematic overview of the multiple frequency bands FB1, FB2, FB3 through which a signal can be transmitted via the circuit device 1 is shown. In each case, a lower cut-off frequency fmin1, fmin2, fmin3 and an upper cut-off frequency fmax1, fmax2, fmax3 of these frequency bands FB1, FB2, FB3 are shown. The bandwidths of the multiple individual frequency bands FB1, FB2, FB3 are obtained as the difference between the band-specific upper cut-off frequencies fmax1, fmax2, fmax3 and the band-specific lower cut-off frequencies fmin1, fmin2, fmin3. Also shown are the center frequencies fc1, fc2, fc3 of the multiple individual frequency bands FB1, FB2, FB3. These center frequencies are obtained as the sum of the band-specific lower frequencies fmin1, fmin2, fmin3 and half of the mentioned bandwidths.

[0158] In order to identify in which of these frequency bands FB1, FB2, FB3 the signal being transmitted is, the frequency of the reference signal can be adjusted to the center frequency fc1 of the first frequency band FB1 in a band identification step. The cut-off frequency of the filter device 16 can then be adjusted to, for example, half of the value of the bandwidth of the first frequency band FB1. If it is subsequently detected that the signal power of the signal provided by the device 17 (see, for example, Figure 1 ) is greater than a predetermined threshold or equal to the predetermined threshold, it is identified that a signal is being transmitted in the first frequency band FB1.

[0159] However, alternatively, the frequency of the reference signal can also be adjusted to the minimum frequency (i.e., the band start frequency) of the first frequency band FB1 during the band identification step. A cut-off frequency of the filter device 16 can then be adjusted to, for example, the value of the bandwidth of the first frequency band FB1. If the signal power of the signal provided by the device 17 is then detected to be greater than a predetermined threshold or equal to the predetermined threshold, it is recognized that a signal is being transmitted in the first frequency band FB1.

[0160] If the detected signal power is less than the predetermined threshold, it is recognized that no signal is being transmitted in the first frequency band FB1. In this case, in another band identification step, the frequency of the reference signal can be adjusted to the center frequency fc2 of the second frequency band FB2 and the cut-off frequency of the filter device 16 can be adjusted to half of the bandwidth of the second frequency band FB2 or the band start frequency of the second frequency band FB2 and the bandwidth of the second frequency band FB2. If the signal power of the signal provided by the device 17 (e.g., see Figure 1 ) is then detected to be greater than a predetermined threshold or equal to the predetermined threshold, it is recognized that a signal is being transmitted in the second frequency band FB2.

[0161] If the detected signal power is less than the predetermined threshold, it can be recognized that no signal is being transmitted in the second frequency band FB2. In this case, in yet another band identification step, the frequency of the reference signal can be adjusted to the center frequency fc3 of the third frequency band FB3 and the cut-off frequency of the filter device 16 can be adjusted to half of the bandwidth of the third frequency band FB3 or the band start frequency of the third frequency band FB3 and the bandwidth of the third frequency band FB3. If the signal power of the signal provided by the device 17 (e.g., see Figure 1 ) is then detected to be greater than a predetermined threshold or equal to the predetermined threshold, it is recognized that a signal is being transmitted in the third frequency band FB3. If the detected signal power is less than the predetermined threshold, the corresponding identification can then continue.

[0162] Figure 6 A schematic diagram showing the first frequency band FB1 with six channels K1, K2, K3, K4, K5, K6 is shown. Also shown are the center frequencies fk1, fk2, fk3, fk4, fk5, fk6 of these channels K1,..., K6. A bandwidth BBK of the channels K1,..., K6 is also shown, where Figure 6 the channels K1,..., K6 in

[0163] have different bandwidths BBK from each other. Of course, it is conceivable that the different channels K1,..., K6 have the same bandwidth. Figure 7In a channel identification step with detailed explanation, it is checked which of the channels K1, ..., K6 in the first frequency band FB1 the signal being transmitted is in, and which of the channels K1, ..., K6 in the first frequency band FB1 the multiple signals being transmitted are in. For this purpose, the aforementioned grid check can be performed.

[0164] For example, if it has been identified that a signal being transmitted is in a frequency band FB1, FB2, FB3 or a channel K1, ..., K6, the corresponding adjusted frequency of the reference signal and the cut-off frequency can be stored, for example, by the control and evaluation device 7. Then, the identification can be terminated or another band identification step or another channel identification step can be performed, for example, to identify the frequency band FB1, FB2, FB3 or channel K1, ..., K6 in which the additional signals, especially the simultaneous ones, being transmitted via the circuit device 1 are. At a later time point, the stored frequencies can be retrieved, and the level of the signal being transmitted in the corresponding frequency band FB1, FB2, FB3 or the corresponding channel K1, ..., K6 can be quickly determined again. This can be used to perform, for example, monitoring of the corresponding frequency band FB1, FB2, FB3 or channel K1, ..., K6. The stored frequencies can also be used to monitor the corresponding frequency band FB1, FB2, FB3 or the corresponding channel K1, ..., K6 using Figure 3 the monitoring part shown.

[0165] Figure 7 A schematic flow chart showing a method according to the invention for identifying a frequency band FB1, FB2, FB3 or a channel K1, ..., K6 in which a signal is being transmitted. In a first step S1, a decoupled signal is provided, for example, by Figure 1 the signal coupler 9 shown. In a second step S2, a reference signal of a predetermined frequency is provided, especially by the device 15 for generating a reference signal.

[0166] For example, it can be checked whether a signal is being transmitted in a first frequency band FB1. For this purpose, the frequency of the reference signal can be adjusted to a band start frequency (for example, 1920 MHz) or a band end frequency (for example, 1980 MHz), and the cut-off frequency of the filter device 16 designed as a low-pass filter device can be adjusted to 60 MHz.

[0167] The reference signal and the decoupled signal are mixed in a third step S3 and filtered in a fourth step S4, especially by means of the filter device 16. In a fifth step S5, the signal power of the filtered signal is determined. In a sixth step S6, the signal power is compared with a predetermined threshold (identification threshold), where, as a function of the frequency of the reference signal, a frequency band FB1, FB2, FB3 (seeFigure 5 ) The frequency is allocated or channels K1, ..., K6 are allocated to the frequency. In this case, for the first frequency band, if the signal power is greater than or equal to the predetermined threshold, the frequency band / channel in which a signal is being transmitted is identified.

[0168] If the signal power is less than the predetermined threshold, it is identified that the frequency band / channel or signal transmission is not in the frequency band or channel being examined. The order from the first step to the sixth step S1, ..., S6 can also be referred to as a band or channel identification step. As described above, not only in the case of identification but also in the case of non-identification, another band or channel indication step can be performed, for example, to identify a frequency band or channel in which another signal is being transmitted or to identify a channel in which a signal is being transmitted in one of the identified frequency bands FB1, FB2, FB3. When performing another band or channel identification step, the frequency of the reference signal and the cut-off frequency of the filter device 16 can be changed. For example, if it is to be checked whether a signal being transmitted is in the third frequency band FB3, the frequency of the reference signal can be adjusted to the corresponding band start frequency (e.g., 1710 MHz) or the corresponding band end frequency (e.g., 1785 MHz) and the cut-off frequency of the filter device 16 can be adjusted to the corresponding bandwidth (e.g., 75 MHz).

[0169] As an alternative to comparing the signal power with a predetermined threshold to identify a signal transmission in a frequency band / channel, as explained, the corresponding frequency of the reference signal and the corresponding cut-off frequency of the filter device 16 can also be adjusted for multiple bands / channels in various cases, and the band-specific signal power of the filtered signal can be determined and stored. Then, the band / channel with the maximum band-specific signal power that is allocated a predetermined amount greater than the band-specific signal power allocated to other bands / channels and / or a band-specific signal power can subsequently be identified as the frequency band / channel in which a signal transmission is taking place.

[0170] The identification of the frequency band / channel or frequency bands / channels in which a signal transmission is taking place, as explained, is preferably performed within a predetermined time period, for example, less than 10 ms.

[0171] As described above, if a frequency band is identified in which a signal transmission is taking place, the band-specific channel or channels of the identified frequency band in which the signal transmission is taking place and their respective channel bandwidths can also be identified. This can be performed in a so-called channel identification step.

[0172] For this purpose, the cut-off frequency of the filter device 16 can be adjusted to a predetermined interval width, for example, adjusted to 200 KHz. Then, starting from the band start frequency of the identified frequency band, the frequency of the reference signal can be incremented by the predetermined interval width up to the band end frequency, wherein for each of these reference signals adjusted in this way, the signal power of the filtered signal is determined and stored as segment power, wherein the signal power is also determined for the band start frequency. During this increment process, a reference signal can be generated for each of the adjusted frequencies for a predetermined time period, and the predetermined time period can depend on the settling time of the device for generating the reference signal, the measurement time of the device for determination, and the evaluation time required by the control and evaluation device. After this time period has elapsed, the corresponding increment can be performed.

[0173] In other words, the frequency band is stepped through continuously in its entirety, wherein the signal power of the filtered signal is determined in each case for segments of 200 KHz width of the frequency band.

[0174] Then, as described above, one or more channels in which a signal transmission is taking place and the corresponding bandwidths can be identified as a function of the stored segment power.

[0175] Figure 8 A schematic flow chart of a method in another embodiment according to the present invention is shown. Shown here is a step S0 for detecting a signal transmission before performing the identification step, wherein this step S0 is performed in particular using Figure 2 the device shown for signal transmission detection. If it is detected that a signal is being transmitted via the circuit arrangement 1, an identification step is started.

Claims

1. A circuit device (1) for transmitting uplink signals and downlink signals between at least one terminal device (2) and at least one antenna (5), wherein, the circuit device (1) includes at least one signal coupler (9) for providing a decoupled uplink signal or downlink signal, characterized in that, the circuit device (1) includes at least one device (15) for providing a reference signal having at least two or more adjustable frequencies, the at least two or more adjustable frequencies being adjusted in an identification step, wherein the circuit device (1) includes at least one mixer (14) for mixing the decoupled signal and the reference signal and at least one filter device (16) for low-pass or band-pass filtering of the mixed signals, wherein the circuit device (1) includes at least one evaluation device (7) for evaluating the filtered signal, wherein at least one frequency band (FB1, FB2, FB3) or at least one channel (K1, …, K6) in which the signal being transmitted is transmitted can be identified depending on the adjusted frequency of the reference signal and at least one signal characteristic of the filtered signal; and wherein the cut-off frequency of the at least one filter device (16) is adjustable and is selected based on the deviation between the frequency of the reference signal and the carrier frequency of the decoupled signal.

2. The circuit device according to claim 1, characterized in that, the circuit device (1) includes a device (17) for determining a signal power of the filtered signal.

3. The circuit device according to claim 1, characterized in that, the device (15) for providing the reference signal is designed as a phase-locked loop or includes such a phase-locked loop.

4. The circuit device according to claim 3, characterized in that, the circuit device (1) includes at least one control device (7) for adjusting the frequency of the reference signal and / or for adjusting the cut-off frequency of the filter device (16).

5. The circuit device according to claim 4, characterized in that, the circuit device (1) includes at least one device for signal transmission detection.

6. The circuit device according to any one of claims 1-5, characterized in that, the circuit device (1) includes at least one switching element (10), wherein in a first switching state of the switching element (10), a first port (9a) of the signal coupler (9) is connected to the mixer (14), and in another switching state of the switching element (10), another port (9b) of the signal coupler (9) is connected to the mixer (14).

7. The circuit device according to any one of claims 1-5, characterized in that, the circuit device (1) includes a bypass device (11), wherein a signal is transmitted between the signal coupler (9) and the mixer (14) via the bypass device (11).

8. The circuit device according to claim 1, characterized in that, At least one channel (K1, …, K6) through which a transmitted signal is transmitted can be additionally identified as a function of another frequency to be adjusted and the at least one signal characteristic.

9. The circuit device according to claim 8, characterized in that the channel (K1, …, K6) can be additionally identified as a function of an adjusted cut-off frequency of the filter device (16).

10. The circuit device according to any one of claims 8 or 9, characterized in that a channel bandwidth of the identified channel can be additionally determined.

11. A method for identifying a frequency band (FB1, FB2, FB3) or a channel (K1, …, K6) through which an uplink signal or a downlink signal is transmitted, wherein: · providing a decoupled uplink signal or downlink signal, · providing at least two or more reference signals with adjustable frequencies, · mixing the decoupled signal and the reference signals, · filtering the mixed signals by a filter device (16), wherein a cut-off frequency of the filter device (16) is adjustable and is selected based on a deviation between a frequency of the reference signal and a carrier frequency of the decoupled signal, · determining at least one signal characteristic of the filtered signal, · the frequency band (FB1, FB2, FB3) or the channel (K1, …, K6) through which the transmitted signal is transmitted is identified as a function of the frequency of the reference signal and the at least one signal characteristic of the filtered signal.

12. The method according to claim 11, characterized in that frequency-specific reference signals with different frequencies are generated, wherein the frequency-specific reference signals are mixed with the decoupled signal in each case, the frequency-specific mixed signals are filtered and at least one signal characteristic of the frequency-specific mixed signals is determined, wherein the frequency band (FB1, FB2, FB3) is determined as a function of the frequency-specific signal characteristic.

13. The method according to claim 11, characterized in that after the frequency band (FB1, FB2, FB3) is identified, a channel (K1, …, K6) in the frequency band (FB1, FB2, FB3) is subsequently identified.

14. The method according to claim 13, characterized in that a channel bandwidth of the channel (K1, …, K6) is identified.

15. The method according to any one of claims 11-14, characterized in that after the frequency band (FB1, FB2, FB3) or the channel (K1, …, K6) of the transmitted signal is identified, monitoring of at least one signal characteristic and / or identification of another frequency band (FB1, FB2, FB3) or another channel (K1, …, K6) is started.

16. The method according to claim 15, characterized in that monitoring and identification of another frequency band (FB1, FB2, FB3) or another channel (K1, …, K6) are carried out sequentially or simultaneously.

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