DD267860A5 - METHOD FOR RECEIVING A RECORD OF DIGITAL INFORMATION TRANSMITTED WITHIN A BROADCASTING NN - Google Patents

Abstract

The invention relates to a method for the reception-side evaluation of digital information transmitted within a broadcasting signal. In the radio data system, digital information (AF code and / or PI code) is transmitted within a broadcasting signal, from which it can be directly deduced or deduced on which alternative broadcasting frequencies the program signal of the current receiving frequency is also receivable. The alternative to the current reception frequency transmission frequencies are determined by evaluation of the AF code and / or the PI code. In this way, a receiving part of the receiver can be tuned to the alternative frequencies one after the other for a short time, whereby the reception quality for each alternative frequency as well as for the momentary receiving frequency is determined. The optimum reception frequency is the frequency which currently offers the best possible reception quality. The received quality is evaluated on the basis of the program signal distortions alone or in addition to the received field strength, whereby the detected bit errors in the RDS data signal are used as a measure for the program signal distortions. In order to improve the quality of reception, the alternative frequencies transmitted as frequency pairs together with a corresponding transmitter operating frequency are addressed and, if necessary, stored in accordance with the respectively immediately preceding or following transmitter operating frequency. On the receiving side, means for selecting another alternative frequency are provided in the event that the alternative frequency currently offering the best possible reception only enables acoustically distorted reproduction. Fig. 1

Description

A method of receiving side-by-side digital information transmitted within a broadcast signal

Field of application of the invention

The invention relates to a method for the reception-side reading of digital information transmitted within a broadcast signal «

The invention also relates to a method according to the preamble of patent claim 3. The invention further relates to a method according to the preamble of claims. Finally, the invention relates to a method according to the preamble of claims.

Characteristic of the known state of the art

Methods of the type mentioned are, for example, in the Techniechen document Doc. Techn. No. 3244 of the European Broadcasting Union. In the specified there Radio Data Syetem (RDS) is the transfer of additional information, eg. B. the transmission of alternative frequencies (AF code), in particular in the form of list summarized alternative frequencies, provided as the content of a modulated on a 57 kHz subcarrier data stream. Oioee Information is of interest for both mobile reception (eg car radios) - for example when leaving the broadcast areas of a station - and stationary reception - for example in the event of a breakdown or disruption of a special one. With suitably trained receivers with memory, such list can be stored and thus reduce the time for setting the receiver to the respective optimum frequency of this list (eg, for optimal reception conditions). "

The ROS Daten8igna1 also includes, inter alia, a so-called P.rogramme Wentifikötion information (PI code), with the aid of the AF code directly and indirectly with the aid of the Pl codoe those alternative transmission frequencies are determined on soft the program signal of current reception frequency is also receivable ·

The reception-side evaluation of the alternative transmission frequencies can be carried out in such a way that the receiver is briefly detected successively to the alternative frequencies for each alternative frequency. Then, the reception field strengths of the alternative frequencies and the instantaneous reception frequency are compared with each other, whereby that frequency is selected and a new reception frequency is set, which delivers the highest measured reception field strength (this, of course, can also be the previously set reception frequency).

However, the problem arises that there are cases in which the measurement of the received signal strength, especially in the case of multipath reception, does not offer a reliable quality statement about the reception. In the case of multipath reception, the reception interference caused by signal dips depends on the detours, on the instantaneous signal output (which is determined by the program type - for example classical music or pop music) and in mobile reception by the vehicle speed. A received signal, which is disturbed by multipath reception, subjectively can be perceived as extremely disturbing despite a relatively high Empfangsfeidstärke between the signal collapses, whereas a received signal, which is gsstört only by noise, 'can be perceived as much better.

As a result, the described selection of the possible reception of a selected program signal can cause the reception to be permanently impaired by multipath reception interference. "This undesirable result can not be significantly changed by the fact that - for example with the aid of a second tuner in the receiver - to the alternative frequencies a longer measurement period is tuned and the measured received field intensities are integrated, since even with such an integration usually the disturbed by multipath reception signals have a higher average reception field strength ale those stimulus signals which are disturbed only by noise.

However, such additional disturbances can not only affect the program signal. The additional information transmitted, for example, in the ROS-Detenet may also be affected, so that it may either be too long waiting times until RDS information has been correctly received again, or else at the receiving end Misinterpretations can come. This is generally particularly negative in weight at Oaten, whose repetition cycle in the data stream is relatively long.

A further problem with program signal quality is due to the transmitter network structure in some countries, particularly in countries with overlapping transmitter networks. Since the digital information sent centrally by a parent, such as a list of alternative frequencies, is received by the parent station If the child's station (eg, translator) does not fit under certain circumstances, it would have to be filtered out to the recipient of the ballot and sent to the child's station.

be replaced with the appropriate list. "This Ausfiltorung and re-feeding is associated with increased effort. Added to this is that the quality of the program signal is also degraded by the filtering.

It has therefore already been proposed (OE-PS 43 32 848) to broadcast from all the stations of a transmitter group a sequence of lists of alternative frequencies "each of these lists at the beginning of the operating frequency of the respective list associated transmitter recovers" from the sequence of Lists to be able to select the appropriate list optimized for the received station ·

However, reliable reception of such a sequence of lists presupposes that the list of the operating sequence of the transmitter assigned to the respective list, which is referred to below as "header", is correctly received. If this is not the case - for example as a result of disturbances due to multipath reception - the alternative frequencies following the header of each lease can not be utilized on the receiving side, even if they are received correctly, because it can not be correctly assigned to the relevant one Operating frequency «

It has therefore already been proposed (Blaupunkt-Werke GmbH "Hildesheim) to transmit all alternative frequencies of a transmitter chain - which may consist of several transmitter groups (eg * BR north and south BR) - in the form of a matrix "With each transmitter the associated alternative frequencies are grouped as matrix neighbors within the matrix." However, this so-called "matrix method" has the disadvantage that due to the grouping rule neighbors

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may be unavoidable, which in reality are not in the above sense alternative frequencies, eo that empfangseeltig entreprechende false agreements can occur on such neighbors. In addition, the harvesting and changing of a matrix is extremely complicated. In some circumstances, it would not be possible to relinquish a freed-up broadcasting frequency simply because an existing matrix would not permit such a change.

Object of the invention

The aim of the invention is to largely avoid the aforementioned disadvantages.

Explanation of the essence of the invention

The invention is based on the object to improve the reception quality in the method of the type mentioned *

This object is achieved according to the invention in that the reception quality is evaluated in such a way that bit errors detected in the received digital information (eg in the received RDS file signal) alone or in addition to the reception are detected as a measure for error correction and / or quality evaluation for program signal distortions to be detected · Field strength can be used ·

The method is further characterized in that the bit errors in the RDS data signal are used to evaluate the program signal distortions such that a) faults occur in the case of bit errors occurring in a bit

Multipath reception or interference;

b) noise is present in uniformly distributed foils)

c) the degree of all disturbances is derived from the block error rate of the block-structured RDS data suitable,

and wherein the following selection messages are derived from the bit errors detected for each alternative transmission frequency and the bit errors detected for the instantaneous reception frequency »

d) if the frequencies under test are essentially only bursty or uniformly distributed bit errors aiifwaieon they will be compared with respect to their block error rate and the frequency with the lowest block rate will be selected for receiver tuning}

e) if the frequencies under test have different bit error distributions, first those frequencies are preselected, which essentially have only bit errors distributed uniformly - possibly depending on that a fixed, maximum permissible block error rate is not exceeded at these frequencies - and ancchließend the preselected frequencies are looked are compared with each other in terms of their block error rate, whereby the preselected frequency with the lowest block error rate is selected for receiver tuning. "

It is also advantageous that the received digital information is subjected to error correction, and that an addressing of the alternative frequencies taking place in accordance with the error-corrected digital information is carried out on the basis of the transmitter operating frequency transmitted in or to each list, possibly several times.

According to another feature, alternative frequencies included in the digital information are transmitted and optionally stored in accordance with their respective immediately preceding or following transmitter operating frequency, respectively transmitted together with an associated transmitter operating frequency. The method is further characterized in that when transmitting each list ale sequence of digital blocks, each with two digital information per block in the rule

a) in the first block of each individual list, an information about the number of alternative frequencies of the respective list and the operating frequency dee associated with the particular rent, and

b) in the remaining blocks of each rivet in each case the Betriebüfrequenz dee the respective list associated special and the alternative frequency

be transmitted·

According to a further feature, on the receiving side, the operating frequency transmitted in the blocks of each lease is used to assign the alternative frequencies to the relevant lease in the sense of a clear, more Ethernet-friendly addressing.

According to another embodiment, the alternative frequencies of all frequency lists r.jr that are stored are used to store and / or use those alternative frequencies whose respective frequency of operation coincides with the currently set receiver frequency of the radio receiver.

The method for the receiver-side averaging of additional information transmitted within a broadcast signal (eg AF code and / or PI code in the ROS signal),

from which directly deductible octar can be deduced "on which alternative transmission frequencies the program suitability of the instantaneous reception frequency is equally catchable, in which the optimal reception frequency is chosen that frequency which currently offers the best possible reception quality according to predetermined criteria. C ₁ is characterized in that the receiver The alternative frequency providing the best possible reception is checked as to whether it allows for an acoustically acceptable reproduction, and that in the event that the alternative frequency being checked allows only an acoustically distorted reproduction another alternative frequency is chosen. Manually adjustable means are used to select another alternative frequency.

According to another embodiment, a signal adjustable means is used to select another alternative frequency, the said signal - optionally also differently weighted - being derived both from the comparison of received field strengths and from the comparison of the field strengths associated low-frequency distortions.

The invention is based on the recognition that the reception quality can be improved on the one hand by the alternative frequencies being transmitted in such a way that they can be assigned more securely to the respective transmitter operating frequencies on the reception side. This has the advantage that the receiver can then be tuned faster if necessary to a better reception bidding alternative frequency. This even applies even if the receiver should have only a small storage capacity.

The invention is also based on the recognition that the quality of reception can be improved by not using the reception field strength for the assessment of the reception quality, or at least the reception field strength, but acoustic and / or program signal distortions. This has the advantage that such alternative frequencies, which only "seemingly" - namely because of a higher reception field strength - provide better reception, but in reality are perceived by the user to be worse, reception can be discarded.

If the additional data transmitted within the broadcast signal are in the form of digital information as in the case of the RDS data signal, the bit errors in the RDS data suitability can be used as a measure of the program-appropriate distortions. It has been shown that the bit errors in the RDS data signal correlate relatively accurately with the program signal distortions, even though the program signal is transmitted in the Baaisband from O to 53 kHz and the RDS data signal is transmitted on a 57 kHz carrier with a minimum of + 1.2 kHz. "

Because of this correlation can be exploited in development of the invention, the fact that disturbances caused by multipath reception or interference bursty bit errors of the RDS data signals, whereas disturbances due to noise uniformly distributed bit errors result. The degree of all disturbances can be derived from the block error rate, which can be determined completely independently of the data content.

Starting from this is for an optimal selection of the

At the momentary reception enabling frequency, a tuner of the receiver is successively tuned to the alternative frequencies as well as to the set reception frequency at timed intervals. For a somewhat more comfortable receiver design, a second tuner of the receiver is provided for optimal selection of the best instantaneous reception frequency, which is successively tuned to the alternative frequencies as well as to the tuned reception frequency of the first tuner at intervals of, for example, at least 2 seconds.

During this tuning interval, which is relatively long in the receiver design with two tuners, the bit errors are detected for the entire RO & D signal received (which, apart from the alternative frequencies, contains a wealth of further information). Subsequently, the bit error distributions and block error rates detected for each alternative frequency and for the current receive frequency are evaluated as follows;

If all checked frequencies are only bursty or uniformly distributed "bit errors, which is equivalent to" that at all frequencies receive signal interference by multipath, interference or noise, the associated block error rates are compared, with that frequency selected with the lowest block error rate as optimum reception frequency "The tuner of the receiver - or in the case of the receiver having two tuners - the first tuner - will then be tuned to this selected frequency unless the reception frequency already set is identical to the selected frequency.

In the event that the frequencies under test have different errors, ie bit errors caused both by noise and by multipath reception, those frequencies which are essentially disturbed by noise and not by way-path reception, ie, which are substantially uniform, are preselected first have distributed errors. In order to exclude strongly freaked signals, only those frequencies can be preselected in whose RDS data signal a maximum permissible block error rate is not exceeded. Subsequently, the preselected frequencies are compared with respect to their detected block error rate, again selecting that frequency with the lowest block error rate as the optimum reception frequency.

The above selection of the optimum frequency can be carried out at a sufficiently long measurement interval per alternative transmission frequency without consideration of the respective reception field strength. In particular, at lower measuring intervals, the reception field strength can additionally be used for the selection, wherein the weighting between reception field strength, on the one hand, and signal distortions, on the other hand, can be determined empirically.

The alternative frequencies can be determined using the Pl-code or the / F-code or using and optionally supplementing - in case of ambiguity or incomplete transmission - of both codes. "The PI-code identifies frequencies on which the same program timed signal is receivable. By comparing the PI code in the station search, an unambiguous assignment of the instantaneous reception frequency and its alternative frequencies can take place. This assignment can be taken directly from the AF code.

If the AF code is not transmitted in the ROS signal or if the AF code is erroneous, the alternative frequencies can also be derived from the PI code.

With the aid of the method according to the invention, it is possible for the first time to obtain the advantages of always optimal reception of radio receivers (both from mobile and from local radio receivers) with the introduction of the RD5 system and the alternative frequencies contained therein by means of a completely new type To realize concept for the determination of the optimal reception quality. In doing so, the problems of the multipath reception of the useful signal can be significantly reduced in a surprising manner with the aid of the RDS data suitability.

In the method according to the invention according to a further embodiment, the sequence of individual lists which are contained in the digital information of the RDS data stream and which on the other side contain alternative frequencies allocated to the respective transmitters of a transmitter or optimized on these respective transmitters or to each list «provided operating frequency of the associated transmitter not only at the top of the list to transmit, but in addition to each individual alternative frequency of the list in question, so that each alternative frequency with the operating frequency" addressed "is. Oede list thus consists of a series of digital information blocks ,! each block consists of two pieces of information. One of these information of each block is (with very specific exceptions) the operating frequency of the sender associated with the respective list. Foils therefore incorrectly transfer part of the list or

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is received, the correctly received alternative frequencies due to their pairing with the operating frequency can be unambiguously assigned to the associated transmitter and enipfangaseitig be sorted in the list, Oa it is unlikely that in a list considered always the same block of information is disturbed, from two or three consecutive received faulty lists of the same sender the complete list are stored at the receiving end.

The above-explained pairing of each alternative frequency with the operating frequency of the transmitter associated with the list increases in comparison to the method according to DE-PS 34 32 848, the number of jo list frequency information to be transmitted to twice, whereby the cycle time for each sequence of lists accordingly is enlarged. One might therefore assume that the probability of reception and security is deteriorated rather than improved for such a prolonged cycle time. In fact, for the above-mentioned matrix method as an advantage over the list method according to DE-PS 34 32 848 the lower cycle duration of a matrix against a sequence of individual lists asserted and hereby a higher reception "safety derived.

It must therefore be surprising for the experts that despite the significant increase in the cycle time of the invention transmitted sequence of lists, the reception reliability is significantly higher than beiir. The matrix method and the generic list method, The nichtvorhersehbara reason for this surprising advantage is that due to the described addressing each alternative frequency

With the operating frequency even with outwardly poor reception conditions still a safe assignment of korfekt received alternative frequencies is possible, which is not the case with the other two methods, eo that their shorter cycle duration in such Empfangesituationern not good.

Ausführunpsbeispiele

Further features, advantages and details of the invention are explained below with reference to three exemplary embodiments with reference to the drawings. Showing:

1 shows a schematic representation of the sequence of lists of alternative frequencies radiated by each transmitter of a transmitter chain according to a first exemplary embodiment of the invention;

Fig. 2: shows a block diagram of a receiver for a method according to a second embodiment of the invention ;

Fig. 3: shows a block diagram of a receiver for a method according to a third embodiment of the invention.

In Fig. 1, a system of alternative lists is shown schematically, which is transmitted as additional information of a broadcasting station. In the example considered, a broadcasting signal is assumed in which a subcarrier of 57 kHz is inserted. The subcarrier may include an amplitude modulation, which is a traffic signal

has to content. Ale modulation or ale further modulation is imprinted on the subcarrier a data signal which is encoded in a particular, not closer interest way. This data signal is transmitted in a consistent form from all the transmitters of a broadcasting chain with the same program, among them all transmitters of the broadcasting chain "Bayern 3 ^M in the coverage area of the Bavarian Broadcasting Corporation (abbreviated: BR) for all the serders of the transmitter chain, in the case shown the list of the transmitter No. 1, the list of the transmitter No. 2, the list of the special No. 3, to the list of the transmitter No. 29 in the case of a transmitter chain with 29 transmitters. CEvery list is tailored to the respective transmitter and contains the vorgeeehenen for this station alternative frequencies, ie the frequencies of those stations that are in the receiver Ange area dee relevant transmitter alternatively be received on the same program. Beiapielsweise can in the Munich area, the program ^M Bayern ^3M alternatively from the transmitter "Wendelstein" o which are received by the transmitter "Ismaning". If the receiver is tuned to the transmitter Wendelstein, then in the event of finely deteriorated reception, Z ₀ B. due to multipath reception, the receiver can briefly tune to the receiver Iamaning and check its reception field strength due to its knowledge of the "alternative" Ismaning! the latter is better, is switched to the transmitter Ismaning, and this test process is virtually inaudible to the listener.

Each list consists of a sequence of digital information blocks, indicated in FIG. 1 as horizontal lines within the lease. Each information block consists of a pair of information, as indicated by the vertical separation of the list into a left and a right half.

indicates 1st. The first block of each list, called the "header", contains in the left half of the block the number of alternative frequencies within the respective rivet. In the case of the list of the transmitter * 1 with four alternative frequencies, the header contains the number # 4 liete dee transmitter no. 29 with eieben alternative frequencies of the header contains the number # 7, in the right half of the block of the header of each list includes the operating frequency of the associated one of the liete transmitter In the case of liete dos transmitter no. 1 with the Betriobsfrequenz 98.5 MHz iet in the right half of the header contain the frequency information 98.5 MHz. In the case of the list dee transmitter No., 29 with the operating frequency 97.9 MHz, the frequency information "97.9 MHz" is transmitted in the header.

In that regard, there is agreement with the method according to DE-PS 34 32 848, There have been transmitted in the following on the header blocks of each list two alternative frequencies, so that in the case of the rent No. 1 with four alternative frequencies on the header two blocks 2 * 2 «4 alternative frequencies follow.

In contrast, in the present exemplary embodiment according to the invention, in each block following the header, the operating frequency assigned to the list is transmitted, together with an alternative frequency. These pairs thus contain the operating frequency ale address for the respective alternative frequency, which has the already mentioned advantage in that the receive security is drastically increased even though the number of blocks required per list which follow the header is doubled.

In the case of Liete det transmitter No. 1, after the header instead of two blocks as in DE-PS 34 32 848 - now four

Transfer blocks werdu. , This brings with it a corresponding increase in transmission time for the sequence of 29 lists. "Since this transmission time equals the cycle duration of each sequence of leases, one might think that as a result of the prolongation of the cycle duration the receive security is worsened in transmission disturbances. This assumption However, as already stated, the surprising effect is that in the case of the method according to the invention according to this exemplary embodiment, despite prolongation of the cycle time, the reception reliability is markedly increased compared with the list method and the Matrlx method.

In the case of stations whose operating frequency is nloht in the 100 kHz grid, but in between (so-called offset frequencies), z. B, is 92.85 MHz, is in the header of the list concerned not the operating frequency, but a special information, an eog, "filler code" according to the document mentioned above the European Broadcasting Union transmitted. In the next block, first the offset frequency, z, B. "92.85 MHz ^M and then the" quasi-operating frequency ", eg," 92.8 MHz "is transmitted following blocks as the address for the alternative frequencies.

A further deviation from the transmission rule for the individual rivets shown in the drawing results if one of the alternative frequencies is an offeet frequency. In this case, instead of the operating frequency, the alternative frequency off-set frequency is transmitted in the corresponding block with the "QuasA alternative frequency", which is in the 100 kHz raster.

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For the identification of alternative frequencies of such transmitters, which are ausegealtet in the context of regional sub-programs for some time a Sendotagee or a broadcast week from the associated transmitter chain, z. The program "Bayern 3" is broadcast from 6 am to 12 pm, the regional program "New from Swabia" from 12 am to 1.30 pm and the program "Bayern 3 ^M " from 1.30 pm to midnight associated block to reverse the order of operating frequency and alternative frequency, so first to transmit the alternative frequency and then the address "Betriebsf requenx" in the block.

Oede Li3te lot tailored to the particular transmitter and contains according to the agreement within the European Broadcasting Union max-eimal 25 frequencies, but usually much less. At the beginning of each list is the operating frequency of the associated transmitter, d. h », boi the list of the transmitter Nr, 1 stands at the beginning the operating frequency of the transmitter No. 1, z. 8, 98.5 MHz, As mentioned, the sequence of 29 lists transmitted by each transmitter of the transmitter chain is transmitted as a data signal «

The receiver receives and decodes dpc transmitted data signal, d. H. the sequence of lists of alternative frequencies. In order to select the currently tuned station list from the list of received listings, the receiver only needs to compare the first frequency of each list with the current tuning frequency, which is feasible even in 29 lists in a very short time. This selection can be done either in on-line mode or in off-line mode, ie. H. without or with caching

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the received sequence of lists. In a preferred embodiment, the selected list is always saved «

Be.i the processing of the received and possibly zwi'schen saved sequence of lists, the receiver selects that list whose first frequency (equal Betriqbsfrequenz the associated transmitter) matches the current tuning frequency. If the first frequency of several lists matches the set operating frequency, all these lists must be selected. Only the selected list (s) will be used for the subsequent tuning of the vote.

This tuning process takes place either by a corresponding command of the listener or automatically when, for example, the currently received station is no longer receptive. In the tuning process, the receiver automatically tunes to the alternative frequencies listed in the selected list (s) and selects the alternative frequency that offers the best possible reception. With the aid of the transmitted data signal ROS, it is also possible to rapidly optimize the tuning of mobile receivers in the case of transmitter chains with more than the specified maximum number of alternative frequencies, without the need to filter and re-search frequency lists at the location of child transmitters.

Fig. 2 shows a block diagram of a receiver for a method according to a second embodiment of the invention. Reference is made to the system described with reference to FIG. 1, although in the second embodiment,

is not important that the additional information is transmitted in digital form.

üie received with an antenna 1, additional oaten containing broadcast signals on the one hand a tuner and on the other hand, a tuner 3, respectively. The tuner 2 is part of a radio receiver with an intermediate frequency amplifier 4 for the intermediate frequency supplied by the tuner and with a demodulator 5 for the recovery of low frequency signals and with an amplifier 6 for the low frequency signals, as well as with a speaker 7 for the acoustic reproduction, to the signal path, z, B, to the output of the tuner 2, a circuit IO for selecting the 57 kHz carrier is connected, which is connected to a circuit 11 for recovering the data. The data is supplied to a memory 12. In this memory 12, the alternative frequencies (AF) of the received by the tuner 2 operating frequency transmitter are continuously read _d The tuner 3 is used for continuous sampling of the receivable by the tuner 2 frequency ranges Its high- or intermediate-frequency output signals are also supplied to the memory. The frequencies sampled by the tuner 3 are constantly compared with the corresponding stored frequencies to provide a measure of the currently best-received station. The frequency to be respectively set by the tuner 3 is determined by the memory 12 by means of a microprocessor 13 via a line 14 and tuned the tuner 3 accordingly.

A circuit 15 is used to measure the field strength of the respective received transmitter, As soon as the field strength measurement shows that the signals of another transmitter a larger

Field strength have ale set by the tuner 2 operating frequency transmitter, the tuner 2 is changed over a line 16 to the special currently larger field strength.

In the circuit described so far, it is possible that distortions of the acoustically reproduced audio signal occur due to interference, eg, those caused by reflections. Such interference usually occurs near very strong stations. Also can occur by a large field strength at the current location receiving an override of the receiver, through which the acoustic playback is distorted.

In known methods, for example, according to the OE-PS 34 48 043, after selecting a special fully automatic voting without the involvement of the user on those stations with the same program allows, which is best receivable at the current recipient site, d. H. the largest field strength supplies.

For this purpose, each transmitter will broadcast not only its own list, but also sequentially the lists of all other transmitters of the same transmitter chain, the operating frequencies of each transmitter are respectively at the beginning of the individual lists. The receiver can thus, after having received all the lists on the basis of its current tuning frequency, select the list belonging to the currently set transmitter by comparing the tuning frequency with the first frequency of each list within the list sequence. Furthermore, the receiver also recognizes the alternative frequencies at which it continues to receive the same program when the coverage area of the currently tuned station is changed.

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can, without having to check the alternetiven frequencies of the other lists. "Switching to another transmitter of the same transmitter chain can be done in this way usually very quickly.

But especially when receiving broadcasters with high applied field strength, the acoustic reproduction may be distorted. For example, this may be due to overdriving due to excessive reception field strength or to interference from reflections,

Boi the present embodiment according to the invention is therefore intended to allow a station setting while maintaining the automatic switching to other, the same program emitting transmitter, in the acoustic distortion during playback are largely avoided or reduced.

By a switch 17, a switching state is generated in the microprocessor 13, in which not the strongest transmitter, but a weaker transmitter, in particular the second strongest transmitter is used for the comparison with the respectively set operating frequency transmitter.

By additional training of the switch 17 as a reset button ensures that the setting of the device can be canceled on stations smaller than the current largest field strength alexander, if the near zone or interference zone of the transmitter is left «A repeated switching operation is facilitated. The effect of the switch 17 on the microprocessor 13 can also be designed so that by multiple repeated tapping of switch 17 all transmitters ent

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the stored alternative list can be set one after the other with decreasing field strength * By a longer actuation of switch 17, z. B, over several seconds ", the reset process can be triggered.

The tuner 3 may have a different design in FIG. 2 than the tuner 2, since its real task is only the scanning of the frequency band to control possibly stronger transmitter. A signal quality does not have to be achieved.

It is also possible, when only one tuner is used, to carry out a field strength change in the described form, although transmitters with lower field strengths can be received by the user during the interrogation process.

Fig. 3 shows in a third exemplary embodiment of the invention a modification of the circuit shown in Fig. 2, in which two flat-valued tuners 2 and 3 are switched into two separate receiver trains A, B, each having a NF output signal NF. deliver NFg to a low frequency switch 18, which in each case forwards one of the two signals to the low-frequency amplifier 6 and loudspeaker 7. From the tuner 2, the data signals (eg from the RDS data stream) by means of the selection circuit 10; 11 and supplied to the memory 12 with microprocessor 13. From the tuner 3, the data signals are also selected and supplied to the memory 12 with microprocessor 13. Tuner 2 is tunable by manual or arbitrary input. Tuner 3 is queried by the memory 12 and the microprocessor 13 via line 14 according to the stored alternative list.

The detection of the respective transmitter with the largest field

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strength takes place in circuit 15 by comparing the received signals from tuner 2 and tuner 3. In the event that with the tuner 2 not the transmitter is set with the optimal field strength to be received, the tuner 3 takes this field strongest transmitter, and its NF- Ausgengssignal NF _ß is placed over the switch 18 to the NF preamplifier 6 and 7 speakers.

In this switching state tuner 2 is queried via line 20 from the microprocessor 12/13 according to the stored in the alternative lists frequencies.

The NF signals NF. and NF _ß are supplied to a circuit 19 for comparing the modulation of both signals. The modulation content of the transmitter set with the largest field strength is compared with the modulation content of the transmitters selected from the alternative list in the case of a modal comparison comparison circuit. This comparison is expediently carried out with the second strongest transmitter from the list.

The comparison can be done by direct comparison of the time course of the low frequency voltage or by comparing the envelopes of the two LF signals. Shows the transmitter with the greater field strength by reflection effect modulation dips or modulation recesses and clipping dor NF by overdriving, switch 18 is automatically switched by the microprocessor 12/13 to the second strongest station, so that the distortions are not visible to the user. If both signals are identical, the transmitter with the greater field strength remains switched off. As a result, the switch 18 can be constantly switched from the currently active receiver A, θ to the respective other receiver B, A, depending on the control of the receiver

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Microprocessor, Only with manual or other input by the user Tuner 2 is initially preferred again to then further the automatic, RDS ~ controlled operation to be subjected.

Claims (10)

ΖίϊίίΟ1- Berlin, the 26.5.1988 69 905/13 Patentanprüche 1. A method for the reception of intra-broadcast digital information (z * B. AF code and / or PI code in the ROe data signal) from which is directly deductible or can be deduced on which alternative transmission frequencies the program signal of the current one Reception frequency is also "reception" is "bar" at the a) alternative transmission frequencies to the current reception frequency are determined by evaluating the Af'-codoe and / or the Pl-code and / or comparable codes, b) a receiving part of the receiver is tuned to one or successively to a plurality of alternative frequencies for a short time and the reception quality is determined for each of these alternative frequencies as well as for the instantaneous reception frequency, c) the optimum reception frequency is that frequency which currently provides the highest possible reception quality, characterized in that the reception quality is evaluated in such a way that the bit errors detected in the received digital information (z, B, in the received ROS signal) are used for error correction and / or quality evaluation for program signal distortions to be detected alone or in addition to the reception field strength « 2. The method according to claim 1, characterized in that the bit errors are used in the RDS data signal to the effect of evaluating the program signal distortions that a) in the case of bit errors occurring in the form of a burst, there are disturbances due to multiple receive or interference) b) there are noises due to noise in the case of uniformly distributed errors; c) the degree of all disturbances is derived from the block error rate of the block structured RDS data signals, and wherein the following selection decisions are derived from the bit errors determined for each alternative transmission frequency and for the instantaneous reception frequency d) if all the frequencies under test have substantially only buret-like or only uniformly distributed bit errors, they are compared with respect to their block error rate, the frequency with the lowest block error rate being selected for receiver tuning; (e) if the frequencies checked have different bit rates Having erroneous distributions, those frequencies are initially preselected, which have substantially uniformly distributed bit errors - possibly depending on the fact that at these frequencies a fixed, maximum allowable block error rate is not exceeded - and then the preselected frequencies are compared with respect to their block error rate, the one preselected frequency with the lowest block error rate is selected for the receiver tuning. 3. A method for the reception-side cancellation of digital information according to the preamble of claim 1 and / or according to claim 1 or 2, wherein the digital information is a sequence of individual, the respective transmitters of a sen- the derkette associated or optimized on these respective stations optimized list altarnativer frequencies, the operating frequencies of each transmitter of the transmitter chain are respectively provided at the beginning of the individual lists, characterized in that the received digital information is subjected to error correction, and that a nacn Maßgabo the error-corrected digital information takes place addressing the alternative frequencies due to the in or: su each list - if necessary multiple - transmitted transmitter operating frequency is made. 4. The method according to one of Aneprüche 1 3 bie, characterized in that contained in the digital information, each transmitted together with an associated transmitter operating frequency as Froquenzpaare alternative frequencies in accordance with their respective immediately preceding or following transmitter operating frequency addressed and optionally stored. 5. The method according to any one of claims 1 to 4 and / or method for transmitting digital information within a broadcast signal as a voting aid in broadcast reception, in which the digital information is a sequence of individual, the respective stations of a transmitter chain associated with or optimized for these respective transmitter lists alternative Frequencies, characterized in that when transmitting each list ale sequence of digital blocks, each with two digital information per block in the rule (a) information on the number of alternative frequencies in the first block of each individual list Respective list and the operating frequency dee the respective list associated transmitter, and b) in the remaining blocks of each individual list respectively the operating frequency of the respective list associated transmitter and the alternative, frequency be transmitted, 6 «method according to claim 5«, characterized in that the receiving side, the operating frequency transmitted in the blocks of each list is used to assign the alternative frequencies to the relevant list in the sense of a clear, interference-free addressing. 7, Method according to one of claims 1 to 6, characterized in that stored by the received alternative frequencies of all frequency lists only those alternative frequencies and / or used for the vote, their respective assigned bet rieb frequency coincides with the currently set receive frequency of the radio receiver " 8 "Method for evaluating additional information (z, B, AF code and / or PI code in the RDS data signal) transmitted within a broadcast signal, from which it is possible to deduce directly or from which alternate sand frequencies the program signal of the current receiving frequency is also receivable, in which ale optimal reception frequency that frequency is selected, which currently - he.tsprechend given criteria - the best possible reception quality offers, and / or ancestors according to one of claims 1 bid 7, characterized in that the receiving side the the -S Currently, the best possible alternative reception is checked as to whether it allows acoustically acceptable reproduction, and that in the event that the alternative frequency being checked only allows acoustically distorted reproduction, another alternative frequency is selected. 9. Ancestors according to claim 8, characterized in that manually adjustable means are used to select another alternative frequency. 10, Method according to claim 8 or 9, characterized in that for selecting a different alternative frequency of ei-'lem signal adjustable means are used, said signal - optionally weighted differently, both from the comparison of received field strengths and from the Comparison is derived from the field strengths associated low-frequency distortions. For this 3 pages drawings