DE102011052734A1 - Method and device for detecting interferers during a transmission - Google Patents

Abstract

The present invention relates to an apparatus and method for performing communication via power lines of a power supply network using a plurality of frequency bands; for receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network, for determining whether at least one signal of the at least one received signal has a predefined interference component, and for lowering a transmission power in at least one frequency band which has been detected for a received signal, a predefined interference component, during communication via power lines of the power supply network.

Description

The subject matter relates to a method and apparatus for performing communication over power lines of a power grid using a plurality of frequency band powerline communication (PLC) is a technology that transmits data over power grids. An energy supply network can be the in-house low-voltage installation as well as the supply network outside the house, or the medium and high-voltage conductors in the large interconnected networks of energy suppliers.

The PLC modulates the data to be transmitted as a high-frequency signal to the electrical lines of the power supply network. The frequencies used in the current technical implementations are in the range between 9 kHz and 100 MHz, although this frequency range can also be extended upwards and / or downwards.

The high-frequency signals are thereby guided by the copper lines, but due to the unshielded lines and asymmetries of the network, parts of the line network act as an antenna. This antenna effect applies both to the radiation of signals, as well as for the reception alike. This effect depends on the physical conditions and is limited to certain frequencies. This effect results in interference between PLC and broadcasting services operating in the same frequency ranges. The portions of the PLC communication radiated from the lines may interfere with the radio reception due to noise, as well as radio stations received by the lines may interfere with the data communication.

The remedy here is a detection of this antenna effect, with individual frequencies in the PLC system are not used, which are in the frequency range of the broadcasting services. Due to the non-use of these individual frequencies, the data transmission in the PLC system hardly drops, because due to the antenna effect, the possible data rate is greatly reduced anyway on the respective frequency.

In known methods, to detect this antenna effect, the PLC communication is briefly interrupted and the network is monitored for noise. In this transmission break, the individual frequencies are examined for interferers, and the frequencies thus determined are no longer used for further PLC communication.

However, this method has the disadvantage that, on the one hand, a transmission pause must be coordinated between PLC devices and, moreover, no data can be transmitted during the measurement. If necessary, the coordination of the transmission break would necessitate a revision of the PLC standards, because such a break is not planned accordingly in every PLC standard. In addition, the gaps in the data transport resulting from the transmission break would result in significant restrictions on the applications, for example, video streaming would be considerably more difficult or impossible.

From the above-mentioned disadvantages, the object was the object to provide a method and a device with an improved detection of interference in a PLC system.

This object is achieved objectively by a method, comprising: performing communication over power lines of a power grid using a plurality of frequency bands; Receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network; Determining whether at least one signal of the at least one received signal has a predefined noise component; and lowering a transmission power in at least one frequency band in which a predefined interference component has been detected for a received signal during communication via power lines of the power supply network.

This object is objectively achieved by a computer program product for performing communication via power lines of a power supply network, wherein the computer program product comprises a program for carrying out the method.

This object is achieved objectively by a device comprising communication means for performing communication via power lines of a power supply network using a plurality of frequency bands; wherein the communication means comprises receiving means for receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network; the apparatus further comprising detecting means arranged to determine whether at least one signal of the at least one received signal has a predefined noise component; and the apparatus comprises means for lowering a transmission power of the communication means in at least one frequency band in which a received signal has a predefined interference component was detected during communication via power lines of a power grid.

The device can be arranged, for example, in a PLC modem or represent a PLC modem. The communication over the power lines can for example be bidirectional, d. H. the communication means may receive signals with the receiving means and the communication means may comprise, for example, transmitting means for transmitting signals in at least one frequency band of the plurality of frequency bands.

The communication may be based on a frequency division multiplexing technique, such as an OFDM method, wherein a plurality of signals are transmitted in a plurality of different frequency bands. For example, exactly one signal may each be assigned to a frequency band, wherein each signal may have a specific bandwidth in the frequency domain and is associated, for example, with a carrier frequency.

The method comprises receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network. For example, the receiving means may be adapted to at least one signal from a received total signal in which a plurality of signals s ₀ (t), s ₁ (t), ... s _k-1 (t) are modulated contain To extract a plurality of signal s ₀ (t), s ₁ (t), ... s _k-1 (t) and output as the at least one received signal. For example, if OFDM modulation is used, the receiving means may comprise Fourier transform means for extracting the signals modulated on the individual carriers from the received total signal.

The predefined interference component of a received signal may be, for example, a noise component caused by a wireless transmitter, such as a radio transmitter or the like, caused by irradiation of the interference in the power lines and modulation of that interference to the respective transmitted signal in the associated frequency band. The term predefined with respect to the noise component can be understood in this case, for example, such that the predefined noise component differs from a noise component normally contained in a received signal, which may be, for example, white Gaussian noise. Furthermore, the term predefined interference component can be understood in such a way that a predefined interference component identifies an interferer in whose frequency range the device should not communicate via the power lines for reasons of electromagnetic compatibility (EMC) or should radiate no disturbing transmission power. These interferers may be, for example, wireless services such as radio stations, WiFi or the like.

The predefined interference component may for example be superimposed on the respective transmitted signal in one of the plurality of frequency bands, since the determination as to whether at least one signal of the at least one received signal has a predefined interference component takes place during the reception of the at least one signal, d. H. For example, during a PLC communication between the device and another PLC communication device via the power supply network performed communication in which the device receives from the other PLC communication device, the at least one signal.

Thus, the determination of whether at least one signal of the at least one received signal has a predefined interference component, for example, by examining whether a received signal in its reception characteristics of receiving properties of another received signal and / or receiving properties of a trouble-free or Distinguished signal differs. This can be done for example by comparing the respective received signal with at least one other received signal and / or by comparison with stored reception characteristics of interference-free or low-interference transmitted signals.

Subsequently, the lowering of a transmission power takes place in at least one frequency band in which a predefined interference component has been detected for a received signal, during communication via power lines of the power supply network. The transmission power can remain lowered, for example, during the entire subsequent communication for the at least one frequency band. However, for example, a renewed communication in a frequency band for which the transmission power has been lowered can also take place after predefined time intervals, and after recording this communication it is once again determined whether a received signal in this frequency band has a predefined interference component, so that when these are predefined Noise component, the transmission power in this frequency band can be lowered again.

Thus, a disturbance in at least one frequency band during the communication of the device with another device can be detected via power lines of a power supply network and the transmission power in the corresponding be lowered at least one frequency band. Since the detection of the disturbance in the device on the basis of the signals received by the device in the context of this communication, there is the advantage that this communication must not be interrupted to detect the disturbance.

For example, this method can be performed at predefined intervals or permanently.

According to an advantageous embodiment, it is proposed that the lowering of the transmission power in the at least one frequency band comprises the omission of the transmission in the at least one frequency band and / or the filtering of a transmission signal in the at least one frequency band.

The lowering of the transmission power in the at least one frequency band may include, for example, the omission of the transmission in the at least one frequency band and / or the filtering of a transmission signal in the at least one frequency band. Thus, lowering the transmit power in at least one frequency band may include, for example, decreasing the transmit power in the respective frequency band to a predetermined threshold, wherein this predetermined threshold may be selected such that the transmit power radiated by the device in the at least one frequency band is not different disturbing services broadcasting in this frequency band, such as radio stations. For example, this lowering of the transmission power can be achieved by an optional adjustable filter. This predetermined limit may for example also be zero, for example, the transmission in the at least one frequency band is omitted by the device, so that the transmission power is lowered in this at least one frequency band to zero.

According to an advantageous embodiment, it is proposed that the lowering of a transmission power for a frequency band of the at least one frequency band takes place only when a frequency band or a frequency of a set of predefined frequency bands or frequencies lies at least partially in the frequency band in which the transmission power is lowered should.

Thus, for example, be prescribed as a criterion for lowering the transmission power that a frequency band or a frequency of a set of predefined frequency bands or frequencies is at least partially in the frequency band in which the transmission power is to be lowered. This set of predefined frequency bands or frequencies may include, for example, frequency bands and / or frequencies of radio and / or television stations and / or other wireless transmitters, wherein, for example, in step 140 of in 1 or in step 540 of in 5 shown method only a lowering of a transmission power in a frequency band takes place when this frequency band is at least partially in a frequency band of the set of predefined frequency bands or frequencies and / or includes a frequency of the set of predefined frequency bands or frequencies. This set of predefined frequency bands may include, for example, broadcast frequencies according to ITU-R. Hereby, for example, misdetections can be avoided.

According to an advantageous embodiment, it is proposed that the method comprises determining at least one characteristic measure for at least one signal of the at least one received signal, wherein the determination of whether a received signal has a predefined interference component, based on the determined at least one characteristic measure of the respective received signal takes place.

This characteristic measure of a received signal may represent any measure suitable for detecting a predefined noise component on the received signal.

For example, the receiving means may be arranged to output the at least one received signal in the form of time-sampled signals s ₀ (n), s ₁ (n), ... s _k-1 (n), where k is the number of received signals and each of these received signals of s ₀ (n), s ₁ (n), ... s _k-1 (n) is assigned to a frequency band of the plurality of frequency bands, and n represents a sampling time. For example, the sampling may be synchronous with the mains frequency, such as 50 Hz or 60 Hz, or the sampling may be, for example, a multiple of the mains frequency, or any sampling frequency may be used.

According to an advantageous embodiment, it is proposed that the at least one characteristic measure comprise at least one of the following measures: a measure of the signal strength of a respective received signal, a measure of the noise intensity of a respective received signal, and a measure of a signal-to-noise ratio a respective received signal.

For example, a measure of a signal-to-noise ratio SNR for at least one received signal can be determined. This measure can, for example, an SNR value of the respective be received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of an SNR for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is undershot, for example, the noise component for this signal is detected. However, the detection of the interfering component can also be linked to at least one further criterion. Thus, an interferer radiating in at least one frequency band can be detected during reception since the SNR is below the predetermined limit in this frequency band. The predetermined limit value can be determined, for example, by an adaptation, wherein this predetermined limit value is, for example, an SNR value which is below an SNR value of a non-disturbed or only slightly disturbed received signal. In this case, for example, the fact that the SNR of a disturbed received signal is below the SNR of a non-disturbed received signal can be taken into account.

For example, the SNR value of a received signal s _x (n) with x ε {0, 1 ... k-1} based on the division of the power of the corresponding demodulated symbol d _x (n) with x ε {0, 1 ... k - 1} are determined by the estimated noise power of the signal s _x (n). The noise power of a signal s _x (n) can be represented, for example, by r _x (n) ^ 2, where for r _x (n), for example, r _x (n) = (s _x (n) -d _x (n)) or For example, r _x (n) = (s _x (n) -d _x (n) x h _x (n)) where scalar h _x (n) is the channel estimate of the channel in the corresponding frequency band x with x ε {0, 1 ... k - 1}. For example, the received signal s _x (n) may be scaled according to the channel estimate h _x (n), for example by multiplying it by the inverse 1 / h _x (n). For example, under the example assumption of OFDM transmission, _hx (n) may represent the channel estimate of the xth carrier for the symbol at time n. The channel estimate h _x (n) with x ε {0, 1 ... k-1} can be determined, for example, by using training symbols.

For example, an SNR value for a received signal may be determined as follows:

If these SNR calculation rules are used in conjunction with r _x (n) = (s _x (n) -d _x (n) x h _x (n)), the transmit symbol d _x (n) in the counter can be, for example, with correspond to the respective channel estimate h _x (n) scaled transmit symbol d _x (n), ie d _x (n) can be replaced in the counter, for example by h _x (n) d _x (n). However, deviating calculation rules can also be used to determine an SNR value.

Furthermore, for example, a measure of a signal strength for at least one received signal can be determined. This measure can be, for example, the signal strength, such as the signal power or the signal energy of the respective received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of signal strength for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is exceeded, the interference component for this signal is detected, for example. However, the detection of the interfering component can also be linked to at least one further criterion. The predetermined limit value can be determined, for example, by an adaptation, wherein this predetermined limit value is for example a value which is above a value of a signal strength of a non-disturbed or only slightly disturbed received signal. Hereby, for example, the fact that a signal disturbed by a disturber and received in the device may contain, in addition to the power of the transmitted signal, the at least partially added power of the interferer, such that the signal strength of a disturbed received signal is above the signal strength of a non-disturbed one received signal can lie.

In addition, for example, a measure of noise for at least one received signal can be determined. This measure may be, for example, a noise power or a noise energy of the respective received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of noise for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is exceeded, the interference component for this signal is detected, for example. However, the detection of the interfering component can also be linked to at least one further criterion. The predetermined limit value can be determined, for example, by an adaptation, wherein this predetermined limit value is, for example, a value which is above a value of a noise a not or only slightly disturbed received signal is. In this case, for example, the fact that a signal disturbed by a disturber and received in the device has a greater noise than a not and not slightly disturbed received signal can be taken into account.

The noise power of a signal s _x (n) can be given, for example, by r _x (n) ^ 2 = (s _x (n) -d _x (n)) ^ 2 or by r _x (n) ^ 2 = (s _x (n ) - d _x (n) * h _x (n)) ^ 2, where the scalar h _x (n) represents the channel estimate of the channel in the corresponding frequency band x with x ε {0, 1 ... k - 1} ,

According to an advantageous embodiment, it is proposed that at least one received signal contains digital information, and that the measure of a signal-to-noise ratio and / or the measure of noise for a respective signal of this at least one received signal using an error correction in the detected digital information contained in each received signal.

By way of example, the device for error correction can have an error correction unit which is set up, for example, to perform an error correction for at least one demodulated transmission symbol from the set d ₀ (n), d ₁ (n),... D _k-1 (n). The error correction unit is configured, for example, to determine and output at least one error-corrected transmission symbol dk _x (n) with x ε {0, 1... K-1}.

For example, the at least one error-corrected transmission symbol dk _x (n) for the determination of the SNR value SNR _x (n) and / or the determination of the noise power of a signal, for. By _x (n) = | s _x (n) - dk _x (n) | ^ 2 or by _x (n) = | s _x (n) - dk _x (n) · h _x (n) | ^ 2, to be used. Thus, the accuracy of the SNR detection and / or the noise power determination can be increased.

According to an advantageous embodiment, it is proposed that the determination as to whether a received signal has a predefined interference component is based on at least one of the following criteria being satisfied: the measure of the signal strength of a respective received signal lies above a predefined limit value, the measure for the noise level of a respective received signal is above a predefined threshold, and the measure of a signal-to-noise ratio of a respective signal is below a predefined threshold.

If this first criterion for a received signal is met, then it is possible, for example, to determine a predefined interference component of the received signal, or this first criterion can be linked to other criteria, for example.

For example, the respective limit values, such as an SNR limit, a signal strength limit or a noise level limit, may be determined by measurements.

For example, a noise strength threshold ger (n) may be determined based on a plurality of noise strength values er _x (n) associated with a plurality of frequency bands. For example, L different frequency bands from the set of frequency bands x ε {0, 1 ... k - 1} with 1 <L ≤ k can be selected, wherein an average noise intensity mer (n) is determined for the noise in these L different frequency bands based on the noise intensity values determined in each case for these L, he _x (n). The average noise intensity mer (n) can be obtained, for example, by arithmetic averaging of these different determined noise intensity values er (n), the L different noise intensity values er _x (n) being added up and the sum obtained being divided by the number L. If, for example, L = k, then the average noise intensity mer (n) can be determined, for example, as follows:

According to an advantageous embodiment, it is proposed that in each case a characteristic measure of the at least one determined characteristic measure is in each case assigned to a frequency band, and that in each case a frequency band associated average value for at least one frequency band of the plurality of frequency bands is determined, the respective average based on the characteristic Measurement of the respective frequency band and at least one characteristic measure of at least one frequency band adjacent to the respective frequency band is determined, and wherein the predefined limit value for a respective signal is determined on the basis of the determined for the frequency band of the respective signal mean.

According to an advantageous embodiment, it is proposed that in each case a characteristic measure of the at least one determined characteristic measure is in each case assigned to a frequency band, and that the method comprises the determination of a plurality of deviation measures, wherein in each case a deviation measure of the plurality of deviation measures is a measure of the change between each two characteristic Measures associated with a first and a second frequency band represents.

According to an advantageous embodiment, it is proposed that a deviation measure of the plurality of deviation measures represents the difference between the two characteristic measures which are assigned to this deviation measure.

According to an advantageous embodiment, it is proposed that the determination as to whether a received signal has a predefined interference component is based on at least one of the following criteria being satisfied: a deviation measure exceeds a predefined limit value, and a deviation measure falls below a predefined limit value.

According to an advantageous embodiment, it is proposed that the determination of the at least one characteristic measure take place at several points in time, and the determination as to whether a received signal has a predefined interference component is based on the at least one characteristic measure of the respective received signal determined at different times.

For example, the sampling may be synchronous with the mains frequency, such as 50 Hz or 60 Hz, or the sampling may be a multiple of the mains frequency, so that the determining of the at least one characteristic measure of sampling times takes place.

According to an advantageous embodiment, it is proposed that the determination of the at least one characteristic measure takes place at several points in time and that the determination as to whether a received signal has a predefined interference component is based on the fact that the characteristic measure is met in several successive ones the following time points remains substantially constant.

Thus, it can be avoided, for example, that a characteristic measure for a received signal that is erroneously estimated at a time when the first criterion is fulfilled leads to a lowering of the transmission power in the frequency band of this signal. For example, the first criterion can be linked to the further criterion such that the characteristic measure remains essentially constant for at least two, five, or ten successive points in time, and at the same time the first criterion is met.

In addition, the presence of a temporally constant interferer can be recognized by the further criterion, which can be defined as a predefined interference component, since a temporally constant interferer, such as a radio station, causes the disturbance in at least one frequency band with temporally constant power. Therefore, this further criterion is particularly suitable, for example, for the detection of wireless services, such as radio stations. A disturbance of these wireless, with temporally substantially constant power transmitting services can therefore be avoided in particular using the other criterion, since the affected frequency bands are recognized as from the constant time transmitting interferers and can be reduced in terms of transmission power.

Disturbances generated by electrical consumers in at least one received signal are not determined by using the further criterion as a predefined interference component, since the interference generated by electrical consumers have no time constant power and are therefore not detected as a noise component. Since such electrical consumers, such as drills or Saftmixer, typically are not disturbed by signals from a PLC modem, the affected frequency bands for EMC reasons, must not be turned off, but it can, for example on these affected frequency bands continue data communication, such as. B. with lowered bit rate by increased error protection done.

According to an advantageous embodiment, it is proposed that the determination of whether a received signal has a predefined interference component is based on at least one of the following criteria: the at least one characteristic measure of a respective signal determined at different times substantially corresponds to a disturbance pattern of a predetermined group of first Interference patterns, and the determined at different times, at least one characteristic measure of a respective signal substantially does not correspond to a disturbance pattern of a predetermined group of second interference patterns.

This at least one following criterion is referred to below as at least a second criterion, wherein the term "second criterion" is not to be understood as limiting that in addition to this second criterion forcibly still further criteria for determining whether a received signal has a predefined noise component can be used.

For example, the detection means may be configured to check at least one of the at least one second criterion to determine whether a received signal has a predefined interference component.

The predetermined group of first interference patterns includes, for example, interference patterns of such interferers in which the corresponding frequency bands should not be disturbed by the transmission power of the PLC modem. These interferers may represent, for example, wireless services, such as radio stations. Thus, the second criterion is positively determined if the determined at different times at least one characteristic measure substantially corresponds to a disturbance pattern from this predetermined group of first disturbance patterns, and with a positive second criterion, for example, the presence of a predefined noise component can be determined. This second criterion can, for example, be ANDed with the first criterion and / or the combination of the first and further criteria so that the determination of the predefined interference component takes place only if this AND connection is fulfilled.

If the time for the SNR is a measure of the at least one characteristic measure, it is possible, for example, to determine a disturbance pattern for each of these interferers via a statistical evaluation, which comprises a typical sequence of temporally successive SNR values in the case of a frequency band disturbance or with multiple frequency bands , These sequences of temporally successive SNR values are determined, for example, for one or more received signals during the performance of a communication over the power lines, in order for the scenario, during the determination of this typical sequence, to correspond to the real scenario, i. H. the reception of at least one signal and the simultaneous detection of the noise component in the at least one signal comes as close as possible.

This typical sequence may be stored as a glitch pattern in the group of first glitches, such that the recognition of these typical sequences of temporally consecutive SNR values with respect to the determined temporally successive SNR values indicates that the corresponding interferer belongs to the group of first disturbing patterns generates this disturbance, and therefore a lowering of the transmission power of the one or more frequency bands is necessary. Likewise, for example, typical sequences of temporally successive signal strength values and / or typical sequences of temporally successive noise power in one or more frequency bands may be statistically determined and stored as a noise pattern in the group of first interference patterns, respectively.

The predetermined group of second disturbance patterns contains disturbing patterns of such interferers in which the corresponding frequency bands can be readily applied to the transmission power of the PLC modem. These interferers may be, for example, electrical loads which, during their operation, generate electromagnetic interference in frequency bands of the PLC modem, which frequency bands are not used for the functionality of these electrical consumers. For example, these electrical consumers can be electrical consumers equipped with an electric motor.

If the measure for the SNR is one of the at least one characteristic measure, then a disturbance pattern can be determined, for example, for each of these electrical consumers via a statistical evaluation, which is an example of a typical sequence of temporally successive SNR values in case of disturbance of a frequency band or multiple frequency bands includes. These sequences of temporally successive SNR values are determined, for example, for one or more received signals during the performance of a communication over the power lines, so that the scenario, while determining this typical sequence, corresponds to the real scenario, i. H. the reception of at least one signal and the simultaneous detection of the noise component in the at least one signal comes as close as possible.

This typical sequence may be stored as a glitch pattern in the set of second glitches, such that the recognition of these typical sequences of temporally successive SNR values with respect to the determined temporally successive SNR values indicates that the corresponding electrical load is the glitch generated, and therefore no shutdown of the one or more frequency bands is necessary. Similarly, for example, typical sequences of temporally successive signal strength values and / or typical sequences of temporally successive noise power in one or more frequency bands may be statistically determined and stored in the group of second interference patterns.

By way of example, a predefined interference component for a received signal is only determined if the at least one characteristic measure determined at different times does not essentially correspond to a given interference pattern to the given interference patterns. This second criterion can, for example, be ANDed with the first criterion or with the combination of the first criterion and the further criterion.

Thus, for example, recognizing the at least one characteristic measure determined at different times in the predefined group of second interference patterns can be used to detect a noncritical interference, wherein this recognition can directly determine that the corresponding frequency band of the received signal does not include a predefined interference component. Hereby, the shutdown of the corresponding frequency band can be avoided.

Recognition of a disturbance pattern from the predetermined group of first disturbance patterns and / or from the predetermined group of second disturbance patterns, d. H. Comparing whether the at least one characteristic measure of a respective signal determined at different points in time essentially corresponds to a disturbance pattern from the group of the first and / or second disturbance patterns can be based, for example, on the determination of a correlation value between a plurality of at different times, such as successive points in time, determined at least one characteristic measure and in each case a disturbance pattern of the group of first disturbance patterns and or the group of second disturbance patterns carried out.

Thus, for example, collected statistical values about the interfering behavior of interferers, such as radio transmitters and / or electrical consumers, in the form of the determined interference patterns of the group of first interference patterns and / or the group of second interference patterns can be used, for example, a reliable detection of the interferers the group of first interference pattern to detect and accordingly to perform the lowering of the transmission power in the corresponding at least one disturbed frequency band.

Since no transmission pauses are necessary for this method, for example, a coordination of the transmission pause between PLC modems to identify the interferer can be omitted. Thus, for example, this method or device may be implemented without altering the standards underlying PLC technology.

The invention will be explained in more detail below with reference to exemplary embodiments showing drawings.

In the figures show:

1 an exemplary method according to a first embodiment;

2 an exemplary device according to a first embodiment;

3 an exemplary frequency spectrum having a plurality of signals;

4 an exemplary device according to a second or third embodiment;

5 an exemplary method according to a fourth embodiment;

6 exemplary determined characteristic measures in an exemplary frequency spectrum; and

7 an exemplary method according to a fifth embodiment;

1 shows an exemplary method 100 according to a first embodiment. This exemplary procedure 100 will be described below together with the in 2 illustrated exemplary device 200 explained according to a first embodiment.

The procedure 100 comprises performing communication over power lines of a power grid using a plurality of frequency bands as exemplified in step 110 shown. This communication can be through the in 2 illustrated communication means 210 the device 100 be made, the communication means 210 for example, receiving means 220 for receiving one or more signals from a port 201 have an input 212 the receiving means 220 with the connection 201 connected is. The means of communication 210 For example, transmission means can also be used 230 for transmitting one or more signals, wherein the transmitting means 230 an output connected to the connector 211 for transmitting the or the transmission signals.

The device 200 For example, it may be located in a PLC modem or may be a PLC modem, with the port 201 For example, to connect the PLC modem to a power grid, the PLC can communicate over this port 201 can be done. For example, the port 201 represent a power plug or be connected to a power plug.

The communication over the power lines can be bidirectional, ie the communication means 210 can with the receiving means 220 Receive signals and the means of communication 210 can with the sending means 230 Send signals.

The communication may be based on frequency division multiplexing, such as an OFDM method, where a plurality of Signals are transmitted in a plurality of different frequency bands. 3 shows an example of a frequency spectrum 300 with a plurality of signals S ₀ (f), S ₁ (f), ... S _k-1 (f) in the frequency domain, each signal having a certain bandwidth in the frequency domain and a carrier frequency f ₀ , f ₁ .. f _{k-1 is} assigned. On the ordinate 310 For example, the magnitude of the amplitude or a measure of the power may be plotted.

The procedure 100 comprises receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network, as in 1 exemplary in step 120 represented and which, for example, by the receiving means 220 the means of communication 210 can be carried out. For example, the receiving means 220 be configured to from a received total signal in which a plurality of signals s ₀ (t), s ₁ (t), ... s _k-1 (t) are included modulated, at least one signal from this plurality of signal s ₀ (t), s ₁ (t), ... s _k-1 (t) and at the output 221 the receiving means 220 as the at least one received signal output. For example, if an OFDM modulation is used, the receiving means 220 Fourier transform means comprise extracting the signals modulated on the individual carriers from the received total signal.

Furthermore, the method comprises 100 determining if at least one signal of the at least one received signal has a predefined noise component as in 1 exemplary in step 130 shown. This determination can be made, for example, by the detection means 240 respectively.

The predefined interference component of a received signal may be, for example, a noise component caused by a wireless transmitter, such as a radio transmitter or the like, caused by irradiation of the interference in the power lines and modulation of that interference to the respective transmitted signal in the associated frequency band. The term predefined with respect to the noise component may be understood here such that the predefined noise component is a noise component normally contained in a received signal, for example white Gaussian noise, and / or colored noise, and / or cyclically stationary noise, and / or impulsive noise is different.

Exemplary is in 3 such an exemplary noise modulated onto the signal S4 (f) from a radio station is shown.

The predefined interference component is superimposed, for example, on the respective transmitted signal in one of the plurality of frequency bands, since the determination as to whether at least one signal of the at least one received signal has a predefined interference component takes place during the reception of the at least one signal, ie, for example during a PLC transmission. Communication between the device 200 and another PLC communication device via the power supply network performed communication, in which the device 200 from the other PLC communication device that receives at least one signal.

Thus, the determination as to whether at least one signal of the at least one received signal has a predefined interference component can be carried out, for example, by investigating whether a received signal is free in its reception properties from reception properties of another received signal and / or reception characteristics of a different received signal ., Disturbed signal differs. This can be done for example by comparing the respective received signal with at least one other received signal and / or by comparison with stored reception property of interference-free or low-interference transmitted signals.

Subsequently, the lowering of a transmission power takes place in at least one frequency band in which a predefined interference component has been detected for a received signal, during communication via power lines of the power supply network, as in 1 exemplary in step 140 shown. This lowering can be achieved, for example, by the means for lowering a transmission power 250 be performed. The means for lowering a transmission power 250 For this purpose, for example, in operative connection with the transmitting means 230 stand.

The lowering of the transmission power in the at least one frequency band may include, for example, the omission of the transmission in the at least one frequency band and / or the filtering of a transmission signal in the at least one frequency band. For example, lowering the transmit power in at least one frequency band may include, for example, decreasing the transmit power in the respective frequency band to a predetermined threshold, which predetermined threshold may be selected to be in the at least one frequency band from the device 200 radiated transmit power does not disturb other services transmitting in this frequency band, such as radio stations. For example, this lowering of the transmission power can be achieved by an optional adjustable filter. This given limit value may for example be zero, for example, the transmission in the at least one frequency band of the device 200 is omitted, so that the transmission power is lowered in this at least one frequency band to zero.

For example, the device 200 transmitting means 230 for transmitting at least one signal in each of a frequency band of the plurality of frequency bands, which via an output 211 with the connection 201 can be connected. For example, if by the means for lowering a transmission power 250 it has been found that at least one signal of the at least one received signal has a predefined interference component, the transmission of the transmission means 200 in the corresponding at least one frequency band from the transmitting means 230 be omitted, for example, by not using this at least one frequency band associated at least one carrier.

Thus, with the exemplary method 100 according to a first embodiment and the exemplary device 200 According to a first embodiment, a disturbance in at least one frequency band during the communication of the device 200 detect with another device via power lines of a power supply network and lower the transmission power in the corresponding at least one frequency band. Since detecting the disorder in the device 200 based on that of the device 200 Received signals in the context of this communication, there is the advantage that this communication must not be interrupted to detect the fault.

Determining whether a received signal has a predefined interference component can, for example, be based on a determined at least one characteristic measure of the respective at least one received signal, wherein the method 100 and the detection means 240 For example, the determination of this at least one characteristic measure for at least one signal of the at least one received signal comprises.

This characteristic measure of a received signal may represent any measure suitable for detecting a predefined noise component on the received signal.

For example, the at least one characteristic measure may include at least one of the following measures: a measure of the signal strength of a respective received signal, a measure of the noise strength of a respective received signal, and a measure of a signal-to-noise ratio of a respective received signal.

For example, a measure of a signal-to-noise ratio SNR for at least one received signal can be determined. This measure may be, for example, an SNR value of the respective received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of an SNR for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is undershot, for example, the noise component for this signal is detected. However, the detection of the interfering component can also be linked to at least one further criterion. Thus, an interferer radiating in at least one frequency band can be detected during reception since the SNR is for signals transmitted in the at least one frequency band. The predetermined limit value can be determined, for example, by an adaptation, wherein this predetermined limit value is, for example, an SNR value which is below an SNR value of a non-disturbed or only slightly disturbed received signal. In this case, for example, the fact that the SNR of a disturbed received signal is below the SNR of a non-disturbed received signal can be taken into account.

Furthermore, for example, a measure of a signal strength for at least one received signal can be determined. This measure can be, for example, the signal strength, such as the signal power or the signal energy of the respective received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of signal strength for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is exceeded, the interference component for this signal is detected, for example. However, the detection of the interfering component can also be linked to at least one further criterion. The predetermined limit value can be determined, for example, by an adaptation, wherein this predetermined limit value is for example a value which is above a value of a signal strength of a non-disturbed or only slightly disturbed received signal. Here, for example, the fact may be taken into account that one of a disturber disturbed and in the device 200 received signal in addition to the power of the transmitted signal contains the at least partially added thereto power of the interferer, so that the signal strength of a disturbed received signal on the Signal strength of a non-disturbed received signal may be.

In addition, for example, a measure of noise for at least one received signal can be determined. This measure may be, for example, a noise power or a noise energy of the respective received signal. For example, determining whether a received signal has a predefined noise component may be based on a comparison in which the determined measure of noise for at least one received signal is compared to a predefined threshold. If this predefined limit value for a received signal is exceeded, the interference component for this signal is detected, for example. However, the detection of the interfering component can also be linked to at least one further criterion. The predefined limit value can be determined, for example, by an adaptation, wherein this predefined limit value is, for example, a value which is above a value of a noise of a not or only slightly disturbed received signal. Here, for example, the fact may be taken into account that one of a disturber disturbed and in the device 200 received signal has a larger noise than a not and not slightly disturbed received signal.

4 shows by way of example some features of a device 400 according to a second embodiment, which is based on the in 2 illustrated device 200 according to a first embodiment. The identical features, such as the transmitting means 230 or the connection 201 , are in 4 not shown.

The receiving means 220 ' the device 400 include, for example, an analog-to-digital converter 223 which converts the received total signal into a total digital signal. The digital total signal becomes Fourier transform 224 passed, so that these means for Fourier transformation 224 a plurality of received signals of s ₀ (n), s ₁ (n), ... s _k-1 (n), each of these received signals from s ₀ (n), s ₁ (n), ... s _k-1 (n) is associated with a frequency band of the plurality of frequency bands, and n is a sampling instant of the analog-to-digital converter 223 represents. The receiving means 220 ' For example, they may also have other components, such as an analog front-end or an automatic gain control. The means for Fourier transformation 224 For example, they may represent a DFT or IDFT, or the like.

The device 400 may also include a demodulator 260 which is adapted to demodulate at least one received signal s ₀ (n), s ₁ (n), ... s _k-1 (n). By means of this demodulation can, for example, from at least one received signal s ₀ (n), s ₁ (n), ... s _k-1 (n), the corresponding demodulated transmission symbol d ₀ (n), d ₁ (n), .. d _k-1 (n) are demodulated.

The detection unit 240 ' the device 400 includes a calculation unit 241 which is adapted to calculate at least one characteristic measure of a respective received signal.

For example, the calculation unit 241 be adapted to an SNR value for a at least a received signal from the corresponding demodulated transmission symbol, that is, from d ₀ (n), d ₁ (n), ... d _k-1 (n), and the corresponding received signal from s ₀ (n), s ₁ (n), ... s _k-1 (n). The SNR value of a received signal s _x (n) with x ε {0, 1 ... k-1} can be calculated, for example, based on the division of the power of the demodulated symbol d _x (n) with x ε {0, 1. .. k - 1} are determined by the estimated noise power r _x (n) of the signal s _x (n). The noise power of a signal s _x (n) can be represented, for example, by r _x (n) ^ 2, where for r _x (n), for example, r _x (n) = (s _x (n) -d _x (n)) or For example, r _x (n) = (s _x (n) -d _x (n) x h _x (n)) where scalar h _x (n) is the channel estimate of the channel in the corresponding frequency band x with x ε {0, 1 ... k - 1}. For example, the received signal s _x (n) may be scaled according to the channel estimate h _x (n), for example by multiplying it by the inverse 1 / h _x (n). For example, under the example assumption of OFDM transmission, _hx (n) may represent the channel estimate of the xth carrier for the symbol at time n. The channel estimate h _x (n) with x ε {0, 1 ... k-1} can be determined, for example, by using training symbols.

For example, an SNR value for a received signal may be determined as follows:

If these SNR calculation rules are used in conjunction with r _x (n) = (s _x (n) -d _x (n) x h _x (n)), the transmit symbol d _x (n) in the counter can be, for example, with correspond to the respective channel estimate h _x (n) scaled transmit symbol d _x (n), ie d _x (n) can be replaced in the counter, for example by h _x (n) d _x (n). However, deviating calculation rules may also apply used to determine an SNR value.

Furthermore, the device 400 also an optional error correction unit 270 which, for example, is adapted to perform an error correction for at least one demodulated transmission symbol from the set d ₀ (n), d ₁ (n),... d _k-1 (n). The error correction unit 270 is adapted to determine and output at least one error-corrected transmission symbol dk _x (n) with x ε {0, 1 ... k-1}.

For example, the at least one error-corrected transmission symbol dk _x (n) for the determination of the SNR value SNR _x (n) and / or the determination of the noise power of a signal, for. For example, by _x r (n) = s _x (n) - dk _x (n) or for example by r _x (n) = s _x (n) - dk _x (n) h _x (n), are used. Thus, the accuracy of the SNR detection and / or the noise power determination can be increased.

The calculation unit 241 For example, it can be set up to calculate the signal strength of at least one received signal s _x (n) with x ∈ {0, 1 ... k-1} and or the noise power of at least one received signal s _x (n) with x ∈ { 0, 1 ... k - 1}.

The device 400 can also have a comparator 242 which, for determining whether a received signal has a predefined interference component, checks at least one of the following criteria, referred to below as the first criterion: the measure of the signal strength of a respective received signal lies above a predefined limit value, the measure of the noise intensity of a respective received signal is above a predefined limit, and the measure of a signal-to-noise ratio of a respective signal is below a predefined limit.

If this first criterion for a received signal is met, then, for example, a signaling to the means for lowering a transmission power 250 done to lower the transmission power in frequency band of this signal.

For example, the determination of the at least one characteristic measure may take place at several points in time and the determination as to whether a received signal has a predefined interference component is based on the further criterion that the characteristic measure remains essentially constant at several successive points in time.

Thus, it can be avoided, for example, that a characteristic measure for a received signal that is erroneously estimated at a time when the first criterion is fulfilled leads to a lowering of the transmission power in the frequency band of this signal. For example, the first criterion can be linked to the further criterion such that the characteristic measures remain essentially constant for at least two, five, or ten successive points in time, and at the same time the first criterion is met. For example, the sampling may be synchronous with the mains frequency, such as 50 Hz or 60 Hz, or the sampling may be a multiple of the mains frequency.

In addition, the presence of a temporally constant interferer can be recognized by the further criterion, which can be defined as a predefined interference component, since a temporally constant interferer, such as a radio station, causing the disturbance in at least one frequency band with temporally constant power. Therefore, this further criterion is particularly suitable, for example, for the detection of wireless services, such as radio stations. A disturbance of these wireless, with temporally substantially constant power transmitting services can therefore with the device 400 be avoided in particular using the other criterion, since the affected frequency bands are detected as from the constant time transmitting interferers and can be reduced in terms of transmission power.

Disturbances generated by electrical consumers in at least one received signal are not determined by using the further criterion as a predefined interference component, since the interference generated by electrical consumers usually (except clock signals) have no time constant power and therefore not detected as a noise component become. Since such electrical consumers, such as drills or Saftmixer, typically are not disturbed by signals from a PLC modem, the affected frequency bands for EMC reasons, must not be turned off, but it can, for example on these affected frequency bands continue data communication, such as. B. with lowered bit rate by increased error protection done. In order to avoid a misdetection, for example, a link should take place with a table of the broadcast frequencies to be considered according to ITU-R. Outside of these frequencies, misdetections are thus avoided. This can be done, for example, by checking whether the frequency band in which the transmission power is to be lowered is in a table with predefined frequency bands or frequencies. This table with predefined frequency bands or frequencies may include, for example, broadcast frequencies according to ITU-R and / or that differ from an operator or manufacturer depending on the operating location and thus locally be stored in a suitable database. For example, this review may be in step 540 have the consequence that only the transmission power is lowered in a frequency band, if this frequency band can be assigned to a frequency band or a frequency of the table with predefined frequency bands or frequencies. If the frequency band is outside the frequency bands or frequencies of this table, there is no lowering of the transmission power. Hereby, for example, misdetections can be avoided.

According to a third embodiment, a comparator 242 be adapted to determine whether a received signal has a predefined noise component, at least one of the following criteria, hereinafter referred to as the second criterion to check: The determined at different times at least one characteristic measure of a respective signal substantially corresponds to a disturbance pattern of a predetermined Group of first noise patterns, and the determined at different times, at least one characteristic measure of a respective signal substantially does not correspond to a noise pattern of a predetermined group of second interference patterns.

The predetermined group of first disturbance patterns contains disturbing patterns of such interferers in which the corresponding frequency bands are not to be disturbed by the transmission power of the PLC modem. These interferers may represent, for example, wireless services, such as radio stations. Thus, the second criterion is positively determined if the determined at different times at least one characteristic measure substantially corresponds to a disturbance pattern from this predetermined group of first disturbance patterns, and with a positive second criterion, for example, the presence of a predefined noise component can be determined. This second criterion can, for example, be ANDed with the first criterion and / or the combination of the first and further criteria, so that the determination of the predefined interference component is only ascertained if this AND combination is fulfilled. The comparator 242 Accordingly, it can be set up to check this AND connection and only then to transmit a corresponding signaling to the means for lowering a transmission power.

The predetermined group of second disturbance patterns contains disturbing patterns of such interferers in which the corresponding frequency bands can be readily applied to the transmission power of the PLC modem. These interferers may be, for example, electrical loads which, during their operation, generate electromagnetic interference in frequency bands of the PLC modem, which frequency bands are not used for the functionality of these electrical consumers. For example, these electrical consumers may be electrical consumers equipped with an electric motor.

If the measure for the SNR is one of the at least one characteristic measure, then for each of these electrical consumers a disturbance pattern can be determined by means of a statistical evaluation, which comprises a typical sequence of temporally successive SNR values in the event of a disturbance of a frequency band or of a plurality of frequency bands , These sequences of temporally successive SNR values are determined, for example, from one received signal or multiple received signals during the performance of a communication over the power supply lines, so that the scenario, while determining this typical sequence, corresponds to the real scenario, i. H. the reception of at least one signal and the simultaneous detection of the noise component in the at least one signal comes as close as possible.

This typical sequence may be stored as a glitch pattern in the set of second glitches, such that the recognition of these typical sequences of temporally successive SNR values with respect to the determined temporally successive SNR values indicates that the corresponding electrical load is the glitch generated, and therefore no shutdown of the one or more frequency bands is necessary. Similarly, typical sequences of temporally successive signal strength values and / or typical sequences of temporally successive noise power in one or more frequency bands may be statistically determined and stored in the set of second interference patterns.

For example, a predefined interference component is detected for a received signal only if the at least one characteristic measure determined at different times essentially does not correspond to a disturbance pattern of the given interference patterns. This second criterion can, for example, be ANDed with the first criterion or with the combination of the first criterion and the further criterion. Thus, for example, recognizing the at least one characteristic measure determined at different times in the predefined group of second interference patterns can contribute to the detection of an uncritical interference, wherein this recognition can directly determine that the corresponding frequency band of the received signal does not include a predefined interference component. Hereby, the shutdown of the corresponding frequency band can be avoided.

Recognition of a disturbance pattern from the predetermined group of first disturbance patterns and / or from the predetermined group of second disturbance patterns can be based, for example, on the determination of a correlation value between a plurality of at least one characteristic measure determined at different times, such as successive times a disturbance pattern of the group of first disturbance patterns and or the group of second disturbance patterns take place.

5 shows an exemplary method 500 according to a fourth embodiment, which may be based on the method according to a first embodiment and the exemplary device according to a first or second embodiment.

This exemplary procedure 500 According to a fourth embodiment, for example, for the step 130 determining whether at least one signal of the at least one received signal is a predefined noise component, and for the step 140 for lowering a transmission power in at least one frequency band in which a predefined interference component has been detected for a received signal.

In step 510 For each at least one frequency band of the plurality of frequency bands, an average value is respectively determined, the respective mean value being determined on the basis of the characteristic measure of the respective frequency band and at least one characteristic measure of at least one frequency band adjacent to the respective frequency band.

In the following, it is assumed by way of example and without limitation that the characteristic measure represents a measure of the signal-to-noise ratio SNR _x (n) of the respective signal x, but the characteristic measure can also be a measure of the signal strength or a measure of the noise intensity or else another suitable characteristic measure.

Before the at least one mean in step 510 is determined, for example, values for the characteristic measure for those frequency bands in which no reception takes place, such as in amateur radio frequency bands, for example, each with the value of a characteristic measure of a frequency band adjacent to the respective frequency band. Thus, discontinuities in the set of characteristic measures, with a characteristic amount associated with each frequency band of the plurality of frequency bands, can be avoided. In principle, values for the characteristic measure for those frequency bands in which no reception takes place can be provided with a suitable value for the respective characteristic measure, which cancels a discontinuity to characteristic dimensions adjacent in the frequency range.

In step 510 an average value MW _x (n) is determined for each one x-th frequency band, this average being based on the characteristic measure of the respective frequency band SNR _x (n) and at least one of a characteristic measure SNR _x (k) of frequency bands adjacent to the respective frequency band is determined. Thus, the mean MW _x (n) may represent an average over a plurality of characteristic measures adjacent in the frequency domain, for example, calculating an arithmetic mean.

For example, the MW _x (n) for each one n-th frequency band can be determined as follows, where L is the number of characteristic measures adjacent to the frequency range which are in the frequency range below the respective n-th frequency band, and M is the number in the frequency domain adjacent characteristic measures that are in the frequency range above the respective n-th frequency range represent. It can be L = M. For example, L = M = 3, or L = M = 6, or L = M = 6, but any other values for L and M that are not necessarily equal may be used.

In step 520 For example, for each received signal for which it is to be determined whether this received signal has a predefined interference component, in each case a limit value G _x (n) is determined on the basis of the average value MW _x (n) assigned to the frequency band of the respective received signal. For example, this limit value G _x (n) can be determined on the basis of the respective average value MW _x (n) and an offset value TH, as determined, for example, by forming the difference or the sum between the respective mean value MW _x (n) and the offset value TH , This offset value TH can be chosen, for example, such that the characteristic measure of a received signal without a predefined interference component is, for example, above the limit value G _x (n), for example if the characteristic measure is the signal-to-noise ratio or the signal strength, or if the characteristic Measurement of a received signal without predefined noise component, for example, below the threshold value G _x (n), for example, if the characteristic measure is the noise level. Thus, for G _x (n), for example MW _x (n) -TH, if the characteristic measure is, for example, the signal-to-noise ratio or the signal strength, or G (n) can be, for example, MW _x (n) + TH if the characteristic measure is, for example, the noise level. The offset value TH may, for example, be between 3 dB and 10 dB, for example 3 dB, or 5 dB or 7 dB or 10 dB, but it is also possible to choose a value deviating therefrom.

This in 5 presented procedure 500 can the optional step 530 leave out, and it can step in 540 to check whether a characteristic measure SNR _x (n) of at least one received signal is below the corresponding limit value G _x (n), and if so, in step 550 the lowering of a transmission power for the respective frequency band of the at least one signal, as previously described with respect to the characteristic measures signal-to-noise ratio or signal strength. If the characteristic measure represents the noise strength, then in step 540 be checked whether the characteristic measure for at least one received signal is above the corresponding limit value G _x (n), so that in step 550 the lowering of a transmission power for the respective frequency band of the at least one signal takes place, the characteristic level of which is above the corresponding limit value.

6 exemplifies various determined characteristic measures 610 . 611 . 612 . 613 . 614 . 615 such as B. the determined signal-to-noise ratios for the respective frequency bands. The in 6 exemplified limit 620 For example, it may represent a limit value G _x (n) determined for a frequency band, such as that for the frequency band of the characteristic measure 613 determined limit G ₃ (n). Because the characteristic measure 613 below the determined limit G ₃ (n) 620 can, for example, in step 540 the lowering of the transmission power for the corresponding carrier f ₃ done.

This corresponding limit value can, for example, be regarded as the predefined limit value described above.

Optionally, the procedure 500 for example, a step 530 in which a temporal averaging each of a characteristic measure for at least one frequency band is performed.

ermittelt, werden, wobei P die Anzahl der zu verschiedenen Zeitpunkten ermittelten charakteristischen Maße SNR_x(n) darstellt. Beispielsweise kann P = 3, oder P = 6 oder P = 12 gewählt werden, oder es kann eine andere Anzahl von P zu verschiedenen Zeitpunkten ermittelten charakteristischen Maße SNR_x(n) verwendet werden.Thus, for example, a time-averaged characteristic measure for a respective frequency band can be determined as a function of characteristic values determined for this frequency band at different times, for example by arithmetic averaging. For the non-limiting example that the characteristic measure is a signal-to-noise ratio SNR _x (n), this time-averaged characteristic measure may be, for example,

where P is the number of characteristic measures SNR _x (n) obtained at different times. For example, P = 3, or P = 6 or P = 12 may be chosen, or another number of P characteristic measures SNR _x (n) obtained at different times may be used.

The following can be found in step 540 to check whether a time-averaged measure for at least one received signal is below (or above) the corresponding limit value, this corresponding limit value G _x (n) being determined as described above, and if so, in step 550 the transmission power in the at least one frequency range, which is assigned to this at least one received signal, are lowered.

For example, the step 540 also be carried out both for a time-averaged characteristic measure and for a time-averaged characteristic measure, so that the transmission power is lowered in a frequency range, if either the time-averaged characteristic measure and / or the time-averaged characteristic measure of the signal associated with this frequency range below (or above) the corresponding limit.

gebildet werden. Beispielsweise kann P = 3, oder P = 6 oder P = 12 gewählt werden, oder es kann eine andere Anzahl von zeitlich aufeinanderfolgenden Mittelwerten MW_x(n) für jeweils ein n-tes Frequenzband gewählt werden.Furthermore, for example, a temporal averaging of the in step 510 determined average values MW _x (n) for each one n-th frequency band are made, as by the optional step 515 in 5 is indicated, this time averaging can represent, for example, an arithmetic mean. Thus, for example, P temporally successive averages can be used for each one n-th frequency band, and from this a time-averaged mean value

be formed. For example, P = 3, or P = 6 or P = 12 can be selected, or another number of time-sequential mean values MW _x (n) can be selected for each one n-th frequency band.

Subsequently, for example, in step 520 for each received signal for which it is to be determined whether this received signal has a predefined interference component, in each case a limit value G _x (n) based on the time average assigned to the frequency band of the respective received signal MW _x (n) are determined, wherein the determination of these limit values G _x (n) based on the respective time average MW _x (n) and an offset value TH, analogous to the comments on step 520 for determining the limit value G _x (n) on the basis of the respective mean value MW _x (n) and an offset value TH. The offset value TH for determining these limit values G _x (n) on the basis of the respective time mean value MW _x (n) may take the same values as the offset value TH for obtaining G _x (n) based on the respective average value MW _x (n), but may be different here as well.

For example, this can be done in 5 illustrated method initially without determination of time averages MW _x (n), and then the in 5 be performed again process, with time averages MW _x (n) are determined and in step 520 the limit values G _x (n) based on the respective time average MW _x (n) and an offset value TH are determined. Alternatively, the in 5 For example, the method illustrated may also be modified to the effect that the method is based solely on the time averages MW _x (n) is passed through.

Moreover, in addition to each of the aforementioned criteria, as a further criterion for lowering the transmission power as a criterion, it may be prescribed that a frequency band or a frequency of a set of predefined frequency bands or frequencies lie at least partially in the frequency band in which the transmission power is lowered should. This set of predefined frequency bands or frequencies may include, for example, frequency bands and / or frequencies of radio and / or television stations and / or other wireless transmitters, wherein, for example, in step 140 of in 1 or in step 540 of in 5 shown method only a lowering of a transmission power in a frequency band takes place when this frequency band is at least partially in a frequency band of the set of predefined frequency bands or frequencies and / or includes a frequency of the set of predefined frequency bands or frequencies. This set of predefined frequency bands may include, for example, broadcast frequencies according to ITU-R.

7 shows an exemplary method 700 according to a fifth embodiment, which may be based on the method according to a first embodiment and the exemplary device according to a first or second embodiment.

Before the step 710 For example, values for the characteristic measure for those frequency bands in which no reception takes place, such as in amateur radio frequency bands, for example, may each be provided with the value of a characteristic measure of a frequency band adjacent to the respective frequency band. Thus, discontinuities in the set of characteristic measures, with a characteristic amount associated with each frequency band of the plurality of frequency bands, can be avoided. In principle, values for the characteristic measure for those frequency bands in which no reception takes place can be provided with a suitable value for the respective characteristic measure, which cancels a discontinuity to characteristic dimensions adjacent in the frequency range.

In each case, a characteristic measure of the previously determined characteristic measures can for example be assigned in each case to one frequency band of the plurality of frequency bands.

In step 710 a plurality of deviation measures are determined, wherein in each case a deviation measure of the plurality of deviation measures represents a measure of the change between in each case two characteristic measures which are assigned to a first and a second frequency band.

For example, the two characteristic measures, which are each associated with a deviation measure, in each case lie adjacent to one another in the frequency range, so that the respective first and second frequency bands can be substantially adjacent to one another. For example, the first frequency band may be immediately adjacent to the second frequency band with respect to the plurality of frequency bands.

The deviation measure may represent, for example, any measure which describes a deviation between the two characteristic measures associated with this deviation measure. For example, a respective deviation measure from the plurality of deviation measures may represent the difference between the associated two characteristic measures.

In the following, it is assumed by way of example and without limitation that the characteristic measure is a measure of the signal-to-noise ratio SNR _x (n) of the respective signal x, but the characteristic measure can also be a measure of the Signal strength or a measure of the noise level or even another suitable characteristic measure.

For example, a deviation measure A _x (n) can be assigned to the two characteristic quantities SNR _x (n) and SNR _{x + 1} (n) directly adjacent in the frequency range, whereby the deviation measure A _x (n) is, for example, the two frequency bands x and x + 1 can be assigned. Further, for example, the deviation measure A _x (n) may represent the difference between the two associated characteristic measures: A _x (n) = SNR _x (n) - SNR _{x + 1} (n), or A _x (n) = SNR _{x + 1} (n) - SNR _x (n).

In the optional step 720 For example, a temporal averaging can be carried out in each case of a deviation measure A _x (n), this temporal averaging analogous to that in 5 illustrated step 530 can be done.

ermittelt, werden, wobei P die Anzahl der für die zeitliche Mittelung verwendeten Abweichungsmaße A_x(n) darstellt. Beispielsweise kann P = 3, oder P = 6 oder P = 12 gewählt werden, oder es kann eine andere Anzahl von P Abweichungsmaßen A_x(n) verwendet werden. Dieses zeitliche Mittelung kann beispielsweise für jedes Abweichungsmaßen A_x(n) der Mehrzahl von Abweichungsmaße A_x(n), mit x in {0, ..., k – 1}, vorgenommen werden, wobei die Anzahl der Abweichungsmaße k betragen kann.This time-averaged characteristic measure A _x (n) may be, for example, as follows by arithmetic averaging

where P is the number of deviation measures A _x (n) used for the temporal averaging. For example, P = 3, or P = 6 or P = 12 may be chosen, or another number of P deviation measures A _x (n) may be used. This temporal averaging can be done, for example, for each deviation measure A _x (n) of the plurality of deviation measures A _x (n), with x in {0, ..., k-1}, where the number of deviation measures k can be.

In step 730 It is checked whether one or more of the deviation measures A _x (n), and / or, if the optional step 720 has been executed, whether one or more of the time-averaged deviation measures A _x (n) is above a predefined limit.

For example, is a deviation measure A _x (n) or a time-averaged deviation measure A _x (n) above the predefined limit, for example, a predefined noise component for at least one frequency band can be determined, which is assigned to this deviation measure. The disturbed frequency band can in this case represent that frequency band of x and x + 1, which is assigned to the smaller characteristic measure from the two associated characteristic measures of SNR _x (n) and SNR _{x + 1} (n), if the characteristic measure is the measure for represents the signal-to-noise ratio SNR _x (n) or the measure of the signal strength, or the disturbed frequency band can represent that frequency band of x and x + 1, which corresponds to the larger characteristic measure of the two the measure of deviation or time-averaged deviation measure characteristic dimensions is assigned, if the characteristic measure is a measure of the noise level.

If, for example, the deviation measure is formed by A _x (n) = SNR _x (n) -NRR _{x + 1} (n), then a predefined interference component for the frequency band x + 1 can be determined if A _x (n) exceeds a predefined limit value , For example, this predefined threshold may be greater than zero, for example between 1 dB and 15 dB, such as 1 dB, 3 dB, 5 dB, 9 dB, 12 dB or 15 dB. However, the limit value can also assume deviating values and can also depend, for example, on the characteristic measure. If, for example, the deviation measure is formed by A _x (n) = SNR _{x + 1} (n) -NRR _x (n), then a predefined interference component for the frequency band x can be determined if A _x (n) exceeds a predefined limit value. Equivalently, it can also be examined whether the amount of a deviation value is above a predefined limit value.

This is followed by a step 550 lowering the transmission power for the frequency band or those frequency bands in which, based on the in step 730 comparison, a predefined interference component has been detected.

Alternatively, in step 730 also be checked whether one or more of the deviation measures A _x (n), and / or, if the optional step 720 has been executed, whether one or more of the time-averaged deviation measures A _x (n) is below a predefined limit.

For example, is a deviation measure A _x (n) or a time-averaged deviation measure A _x (n) below the predefined limit, for example, a predefined noise component for at least one frequency band can be determined, which is assigned to this deviation measure. The disturbed frequency band can in this case represent that frequency band of x and x + 1, which is assigned to the smaller characteristic measure from the two associated characteristic measures of SNR _x (n) and SNR _{x + 1} (n), if the characteristic measure is the measure for represents the signal-to-noise ratio SNR _x (n) or the measure of the signal strength, or the disturbed frequency band can represent that frequency band of x and x + 1, which corresponds to the larger characteristic measure of the two the measure of deviation or time-averaged deviation measure characteristic dimensions is assigned, if the characteristic measure is a measure of the noise level.

If, for example, the deviation measure is formed by A _x (n) = SNR _x (n) -NRR _{x + 1} (n), then a predefined interference component for the frequency band x can be determined if A _x (n) falls below a predefined limit value. For example, this predefined threshold may be below zero, for example between -1 dB and -15 dB, such as -1 dB, -3 dB, -5 dB, -9 dB, -12 dB or -15 dB. However, the limit value can also assume deviating values and, for example, also depend on the characteristic measure. If, for example, the deviation measure is formed by A _x (n) = SNR _{x + 1} (n) -NRR _x (n), then a predefined interference component for the frequency band x can be determined if A _x (n) exceeds a predefined limit value. Equivalent to this, it can also be examined whether the amount of a deviation value lies below a predefined limit value.

Moreover, in addition to each of the aforementioned criteria, as a further criterion for lowering the transmission power as a criterion, it may be prescribed that a frequency band or a frequency of a set of predefined frequency bands or frequencies lie at least partially in the frequency band in which the transmission power is lowered should. This set of predefined frequency bands or frequencies may include, for example, frequency bands and / or frequencies of radio and / or television stations and / or other wireless transmitters, wherein, for example, in step 140 of in 1 or in step 540 of in 5 shown method only a lowering of a transmission power in a frequency band takes place when this frequency band is at least partially in a frequency band of the set of predefined frequency bands or frequencies and / or includes a frequency of the set of predefined frequency bands or frequencies. This set of predefined frequency bands may comprise, for example, broadcast frequencies in accordance with ITU-R and / or be stored differently by an operator or manufacturer depending on the operating location and thus locally in a suitable database.

With this method according to a fifth embodiment, narrow-band interferers, such as radio transmitters, for example, can be detected in a simple and reliable manner, for example.

Claims (16)

Method, comprising: Performing communication over power lines of a power grid using a plurality of frequency bands; Receiving at least one signal in at least one respective frequency band of the plurality of frequency bands during the communication via power lines of the power supply network, Determining whether at least one signal of the at least one received signal has a predefined interference component, and - Lowering a transmission power in at least one frequency band in which a predefined noise component has been detected for a received signal during communication via power lines of the power supply network. A method according to claim 1, characterized in that the lowering of the transmission power in the at least one frequency band comprises the omission of the transmission in the at least one frequency band and / or the filtering of a transmission signal in the at least one frequency band. Method according to one of claims 1 and 2, characterized in that the lowering of a transmission power for a frequency band of the at least one frequency band only takes place when a frequency band or a frequency of a set of predefined frequency bands or frequencies lies at least partially in the frequency band, in which the transmission power is to be lowered. Method according to one of claims 1 to 3, characterized in that the method comprises determining at least one characteristic measure for at least one signal of the at least one received signal, wherein determining whether a received signal has a predefined noise component, based on the determined at least a characteristic measure of the respective received signal takes place. Method according to claim 4, characterized in that the at least one characteristic measure comprises at least one of the following dimensions: A measure of the signal strength of a respective received signal, A measure of the noise level of a respective received signal, and A measure of a signal-to-noise ratio of a respective received signal. A method according to claim 5, characterized in that at least one received signal contains digital information, and that the measure of a signal-to-noise ratio and / or the measure of noise for a respective signal of this at least one received signal is determined using an error correction of the digital information contained in the respective received signal. Method according to one of Claims 5 and 6, characterized in that the determination as to whether a received signal has a predefined interference component is based on at least one of the following criteria being met: The measure of the signal strength of a respective received signal is above a predefined limit, The measure of the noise intensity of a respective received signal is above a predefined limit, and The measure of a signal-to-noise ratio of a respective signal is below a predefined limit value. A method according to claim 7, characterized in that in each case a characteristic measure of the at least one determined characteristic measure is assigned to each frequency band, and that the method comprises determining a frequency band associated average value for at least one frequency band of the plurality of frequency bands, wherein the respective average value is determined on the basis of the characteristic measure of the respective frequency band and at least one characteristic measure of at least one frequency band adjacent to the respective frequency band, and wherein the predefined limit value for a respective signal is determined on the basis of the average value determined for the frequency band of the respective signal. Method according to one of claims 3 to 7, characterized in that in each case a characteristic measure of the at least one determined characteristic measure is assigned to a respective frequency band, and that the method comprises determining a plurality of deviation measures, wherein in each case a deviation measure of the plurality of deviation measures a measure of the change between any two characteristic measures associated with a first and a second frequency band. A method according to claim 9, characterized in that a deviation measure of the plurality of deviation measures represents the difference between the two characteristic measures associated with this deviation measure. Method according to one of claims 9 and 10, characterized in that the determination of whether a received signal has a predefined interference component based on that at least one of the following criteria is met: - a deviation exceeds a predefined limit, and - A deviation measure falls below a predefined limit. Method according to one of claims 6-11, characterized in that the determining of the at least one characteristic variable takes place at several points in time and that the determination of whether a received signal has a predefined interference component is based on the fact that the characteristic is satisfied as a further criterion Measurement remains essentially constant in several successive times. Method according to one of claims 3 to 12, characterized in that the determination of the at least one characteristic variable takes place at several times, and the determination of whether a received signal has a predefined noise component, based on the determined at different times at least one characteristic size of respective received signal takes place. The method of claim 13, wherein determining whether a received signal has a predefined noise component is based on at least one of the following criteria: The at least one characteristic measure of a respective signal determined at different points in time essentially corresponds to a disturbance pattern of a given group of first disturbance patterns, and The at least one characteristic measure of a respective signal determined at different points in time substantially does not correspond to a disturbance pattern of a predetermined group of second disturbance patterns. An apparatus comprising: communication means for performing communication over power lines of a power network using a plurality of frequency bands; - wherein the communication means are receiving means for receiving at least one signal in at least one frequency band of the plurality of frequency bands during communication via power lines of the power supply network, - detection means which are adapted to determine whether at least one signal of the at least one received signal is a predefined interference component and means for lowering a transmission power of the communication means in at least one of Frequency band in which a predefined interference component has been detected for a received signal during communication via power lines of a power supply network. A modem for transmitting data over a power supply network, comprising an apparatus according to claim 15.

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