JPH11177448A - Method for evaluating digital signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent audible audio signal interrupt at changeover from being audible by shortening changeover from an actual transmission frequency into a frequency to be checked. SOLUTION: A reception frequency is temporarily change-over from the frequency which is set in adjustment at first into another frequency 19 repeatedly. A receiver reads the bit of a digital signal 20 transmitted by another frequency, which is stayed in another frequency 19 or received during a staying period, and temporarily stores it. Repeated temporary changeover (56-60) is executed at time interval 54, the time interval length is made to be the integral multiple of a group length 52 and made to correspond to the length where a stay continuing time 50 is another frequency 19 is added, and then, the bit of the digital signal 20 which is read during the temporary change-over (56-60) period is evaluated by one evaluation cycle. Thus, the changed for a phase control loop in order to changeover the frequency is made yet smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for evaluating a data signal, for example, an RDS signal, as defined in the preamble of claim 1, wherein the signal has a predetermined length in parallel with a broadcast program. As a group of bits, the signal is transmitted at a transmission frequency different from the transmission frequency actually set by the receiver, where the reception frequency of the receiver is repeatedly adjusted and temporarily set first. Switching from frequency to another frequency, wherein the bits of the digital signal transmitted by that other frequency, which were received during the period when the receiver was staying at said other frequency, are read and temporarily stored. The evaluation method.

[0002]

2. Description of the Related Art "Specifications o
f Radio Data System (RDS)
for VHF / FM Sound Broadcas
ting ”European Broadcasting Union (Europes
Broadcasting from Broadcasting Union)
Via a transmission frequency, in a frame of a radio data system (Radio-Data-System), which is abbreviated as RDS, in addition to a broadcast program, information collected in the form of groups similarly divided into blocks is transmitted. It is known. A transmission frequency or a program chain identifier (program identification code PI) assigned to the transmission frequency exists as a part of the information, and the chain identifier indicates which program is transmitted at each transmission frequency. . Further particularly important information is the program type identifier (Program Type Identifier Code).
e; PTY) and a traffic information program identifier or a traffic information broadcast station identification number (Traffic Program)
mme; TP), and the program format identifier is:
What form of program content, for example pop music,
It indicates whether classical music, sports, etc. are radiated and transmitted by the received program, and the traffic information program identifier indicates whether the received program is a traffic information broadcast program.

According to the above-mentioned specification specification, within the context of the RDS, a very wide variety of groups of information content can be transmitted over transmission frequencies in any order sequence. However, the information (PI, PTY, TP) considered to be particularly important here is common to all group types, and one fixedly assigned one in each group. Can occupy a position.

[0004] In a broadcast receiver known from DE-A-4103061, it is necessary to find a transmission frequency suitable for reception, via which the same program as that transmitted by the actual transmission frequency is transmitted. A program chain identifier is used. For such an alternative frequency check, the reception frequency of the broadcast receiver is determined during the duration of one alternative frequency check, ie its received field strength and the program chain identifier PI assigned to it.
Is switched to the alternative transmission frequency to check for. 20 to 30 msec or 150 to 30
A signal interruption in the region of 0 msec is perceived by click noise and information loss. It is therefore proposed to use an alternative spare signal during the signal gap gap, said alternative spare signal being obtained in a temporary storage from the audio signal section immediately preceding the interruption in question, thus providing a signal interruption. It covers.

[0005] In order to avoid the costs associated with the recording of a preceding audio signal section that has been interrupted, in addition to the broadcast program, the digital signal transmitted at a different transmission frequency than that actually set at the receiver is set. In a method proposed in the applicant's unpublished patent application P19701042.3 for simultaneous non-audible evaluation, using a fast-phase control loop (PLL), the receiver is transmitted on an alternative frequency. Within the duration of one bit of the digital signal, it is switched from the original frequency to the alternative frequency, and is also reset back again. The bits of the digital signal received for the duration of the dwell in which the receiver stays at the alternative frequency are read into the intermediate memory, so that upon repeated switching of the receiver, the bits of the digital signal are stored during successive bits. Within, the complete digital signal transmitted on the alternative frequency is placed in an evaluable state.

[0006]

The problem to be solved by the present invention is that, compared to the broadcast receiver known from DE-A-4 10 306 1, the shorter switching from the actual transmission frequency to the frequency to be checked is achieved. It is another object of the present invention to provide an effect that the audible audio signal interruption performed at the time of the switching is not audible. It also saves the cost for recording the audio signal section prior to the interruption as in the last mentioned prior art.

[0007]

The object is achieved by the features of claim 1. That is, a data signal, for example,
A method for evaluating an RDS signal, wherein the signal is a bit group having a predetermined length in parallel with a broadcast program.
The transmission is performed at another transmission frequency different from the transmission frequency actually set by the receiver, where the reception frequency of the receiver is temporarily changed from the initially set frequency to another frequency. Is switched
Here, the bits of the digital signal transmitted by the other frequency, which are received during the period when the receiver stays at or stays at the other frequency, are read and temporarily stored. In such an evaluation method as described above, the repeated temporary switching is performed at time intervals, and the length of the time interval is set to an integral multiple of the group length, and the dwell duration on the other frequency is set. Corresponding to the added length, the bits of the digital signal read during the temporary switching are evaluated in one evaluation cycle.

[0008] An advantage of the method of the present invention over the last-mentioned prior art is that the alternative frequency is relatively non-time critical and thus fulfills the imposed implications on the phase control loop for frequency switching. This has the effect of requiring even less demand.

[0009] Advantageously, during the switching of the receiver to the alternative frequency, the reproduction of the received program may be interrupted. As a result, disturbing click noise, which is caused, for example, by the transmission of a modulated wave at an alternative frequency different from that at the original frequency,
Is avoided.

An embodiment of the present invention is shown in the drawings and will be described in detail below.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method according to the invention will be described below in the context of a broadcast receiver for the reception of information transmitted according to the RDS scheme, but other digital transmissions structured and transmitted in groups of bits. It is also applicable to information.

In a broadcast receiver for carrying out the method of the present invention shown in FIG. 1, a broadcast signal applied to a receiving antenna 2 is transferred to a receiving unit 2. The receiving unit 2 includes means necessary for receiving and demodulating a broadcast signal-such as an antenna signal amplifier-and an adjustable phase control loop (PLL) for adjusting and matching the receiving unit 2 to a predetermined transmission frequency. , The intermediate frequency section,
A demodulator for demodulating the received broadcast signal; A phase control loop for switching the receiving unit from the first transmission frequency to the second transmission frequency is controlled by the control unit 5 described later in detail. The stereo multiplex signal appearing at the output of the receiver 2, whereby the received transmission frequency is modulated, is sent to the reproduction unit 7 via the mute circuit 6 on the one hand to interrupt the reproduced audio signal. The playback unit 7 has, in a known manner, means for playing back the audio signal contained in the stereo multiplex signal, for example a stereo decoder, an amplifier and a speaker. The mute circuit 6 controlled by the control unit 5 is in the present case configured as a controllable switch, the output of which is connected to a memory, in the simplest case a capacitor. In that way, the coupling capacitors of the following stages are held at the value applied immediately before the interruption of the audio signal, so that
Click noise as a rising transient vibration process is effectively avoided when the switch is opened and closed by the coupling capacitor.

[0013] Alternatively, the mute circuit may be configured as follows: the audio signal is removed according to a predetermined time function in the course of the interruption and is reinserted after a temporary frequency switch. . In that way, it is likewise possible to suppress unpleasant unpleasant clicks.

Further, the stereo multiplex signal is RD
Stereo multiplex (MP
X) is supplied to the input side of the RDS-demodulator 3 connected to the control unit 5 for demodulating the 57 KHz subcarrier. RDS
The output of the demodulator 3 is connected to a memory 4 for storing the bits of the RDS signal; The memory 4 is connected to the control unit 5. Here, the memory 4 has a number of registers represented by o, and in this case, o = 4, each having a length of 104 bits, that is, four registers, so that the RDS signal A total of four groups can be stored. Further, the memory 4 has a result register for inputting the generated bit group of the RDS signal,
The generated bit group of the signal can be supplied by the control unit 5 to a further evaluation unit.

FIG. 2 shows one section of the RDS signal 20, and one section of the RDS signal 20 is transmitted together with a broadcast program at a transmission frequency. RDS signal 20
Consists of bit groups 21, 22, 23 as the largest continuity signal constellation unit, and these bit groups are
Hereinafter, it is also simply referred to as a group. Here, each group is composed of blocks 25 to 28 having a length of 104 bits.
Are subdivided into Each block consists of one information word containing the original information to be transmitted, including the first 16 bits, and words 35 to 38 to be superimposed.
38 consist of control words and offset words formed from information words, which indicate the position of each block in the group.

According to the RDS specification mentioned at the beginning, the RDS
Different information is transmitted by means of signals by different group types, which are transmitted in an order not set by the protocol. FIG. 2 shows, for example, two different group types. In the first group 21 of the type OA of the RDS specification, in addition to the information mentioned later, in the block C (27), in the section marked by 43, an alternative frequency to the actually received transmission frequency ( AF) is transmitted, and in block D (28), the program name (P) of the program transmitted by the actually received transmission frequency is transmitted.
S) Information of 44 is transmitted. In contrast, type 2
Radio text data (RT) 45 is transmitted in blocks C and D (27, 28) of group A of A.

Unlike those information types that differ depending on the group type, information deemed particularly important according to the RDS specification; Program Type Identifier (PTY)-which is the program type via the actual transmission frequency Is transmitted-; traffic traffic broadcast identifier (T
P)-this indicates that the program actually received is the one sending the traffic message-
It is transmitted at the same position within each group, regardless of the group type. Thus, for example, the program chain identifier (PI) 40 occupies the first 16 bits in each of the blocks A25 of each group, and the traffic broadcast identifier (T
P) 41 occupies the sixth bit in block B26, and program format identifier 42 (PTY) occupies bit positions 7-11 in block B26.

The invention takes advantage of the fact that particularly important information to be detected by the method of the invention is transmitted at a fixed position within a group of digital signals, in this case RDS signals. The relevant transmission frequency (AF) data for the transmission frequency that is actually adjusted and set-hereinafter also referred to as the original frequency or the current frequency (MF)-may now be collected in a continuous flow. Absent. rather,
Departure from the original original frequency or current frequency (MF)
Only in a very short time in the range of a few milliseconds, and the alternative frequency is adjusted, so that the interruption in reception of the original or current frequency is inaudible to the listener. During a short-term switch to the alternative frequency, one short bit sample is taken from the data stream 20 transmitted by the alternative frequency. Subsequently, the original frequency or the current frequency is adjusted again and a new data sample is taken after an interval time. A data sample should not contain more than 5 to 8 bits in order to make the interruption in reception of the original or current frequency as inaudible as possible.

In order to detect the relevant data of the alternative frequency,
87. Iterative extraction of alternate frequency data samples;
At least a 104-bit length with a total time of 6 msec
Need to capture an entire group,
That is, to the frame of the digital signal of the alternative frequency
This is because synchronization of the receiver cannot be assumed. Day
The sample size is adjusted as follows:
Adjusted so that 104 bits are obtained after
That is, for example, 15 × 6 Bit + 2 × 7 Bit = 104 Bit, where P = 17 or 26 × 4 Bit, where P = 26 or 13 × 8 Bit, where P = 13. One complete group, two to ensure group detection
Interval between data samples, interval time; T_I=
nxTG + Tv is the group duration T_G= 87.6 ms
(Milliseconds). fixed
Interval time T _IIn the case of
Selection of the dwell duration TV on an alternative frequency for
Allows the alternative frequency star for each data sample
Activated, not activated
Consecutive bit positions within a group
Get out and get caught.

The group of P data samples of the digital signal emitted via the alternative frequency comprises a signal section consisting of P groups of digital signals having different group types with a predetermined probability. Thus, the information content of the group so captured is insignificant and the group or block synchronization is
Like the syndrome calculation, it is hardly possible. It has been proposed to collect a plurality of groups, i.e., an integral multiple of 104 bits, and determine one generated bit group by averaging in order to acquire information-rich or information-rich information. Here, for averaging, evaluation of autocorrelation,
Formation of a moving average value or subsequent addition with a limit value determination can be performed.

For the purpose of averaging, for example, 4, 6 or 8
X104 bits are collected and the actually read bit sequence is combined with the value of the preceding bit sequence to form one generated bit sequence. As a result, the extremum is obtained only at certain points in the generated bit group, assuming that each group from which the data sample is taken has another content, i.e. another group type, i.e. Matching information for the group is obtained, for example, the program chain identifier in block A, the bit position in block B, the program type identifier in positions 7-11 and 6, and the traffic radio data identifier.
That is because the data is repeated 4, 6 or 8 times, added and, unlike the other signal sections, has a statistically different value and thus takes the average value. At the same time, based on averaging over a number of groups, data errors or reading errors are possibly suppressed, since the errors are statistically evenly distributed over a number of groups. is there.

The method of the present invention will be described in detail with reference to FIG. 3 using an example of an RDS signal transmitted in addition to a broadcast program via a broadcast-transmission frequency.

FIG. 3 shows, for example, a section of an RDS signal 20, which is transmitted via an alternative frequency 19. The receiving frequency of the receiver is switched from the original frequency or the current frequency 18 to the alternative frequency 19 at successive times t _i (indicated by reference numerals 56 to 60 in FIG. 3). At time t1--this corresponds in this case to the switching time ti--from the data samples 65-72 to the alternative frequency 1
9 and are temporarily stored in the memory 4 of the broadcast receiver operating using the method of the invention.

As can be seen from FIG. 3, in the present case, the switching time ti to the reading time t _1, at which the data sampling takes place on the alternative frequency 19, is selected as follows: And data samples 65 to 72 are R
It has been selected to be taken from a immediately successive group of DS signals. The spacing between the two groups that are activated and active for data sampling is in this case 1 and therefore n = 1. Marked residence duration at reference numeral 50 in FIG. 3 T _V
Are selected as follows: m = 8 bits are read in the frame of each data sample extraction. Therefore, data samples 65-72 are:
3, including: 65: Bit 25, Block A-Bit 6, Block B; Group 1, 66: Bit 7, Block B-Bit 15, Block B; Group 2, 67: Bit 16, Block B-Bit 24, Block B; Group 3,... 72: Bit 16, Block A-Bit 24, Block A; Two successive data sample extractions (eg, 58,
The interval duration T _I , represented at 54 in FIG. 3 between the starting points of 59), is the group duration _TG , the duration of the data sampling, in other words the dwell duration T _v on the alternative frequency = Corresponding to the time plus mxTB, the group duration _TG is, in the present case, approximately 87.6 ms.
= Equal to 104XTB, T _B is approximately equal to one bit duration. Calculated from time point 56 of the first data sample, the duration for one complete group detection is obtained as follows: T _R = (P−1) XT _I + T _V, where P = T _G / T _V and T I = n × T _G + T _{V As} already mentioned, the detection of a single complete group of RDS signals 20 is not sufficient for the acquisition of intense data, since then the relevant group Can be extracted from different data types and therefore from different data contents. Therefore, it is necessary to form one generation group from a plurality of groups represented by o. From the time of the first data sample, the total duration Tge for reading the o group is as follows: Tges = o × ((p−1) × T _I + T _V ) Therefore, the parameters n = 1 and m = 8 For the example of FIG. 3 with A and O = 4, the overall evaluation duration is:

Tges ≒ 4.5-5 ms The above relational expression holds, of course, only in the following case, ie, when the number of bits read for each data sample is equal for all data samples. Holds only for. Therefore, for the above example p = 17,
This is not the case, where 6 bits each are read during the first, first 15 data samples, and 7 bits each during the last two samples.

So far, the description of FIG. 3 has been based on the following: the switching time ti at which the two reception frequencies are switched from the original or current frequency 18 to the alternative frequency 19 is as follows: It was based on coincidence with time t1, that is, where the extraction of the respective one data sample coincides with time t1 starting from the alternative frequency. What can actually be based on is the applied PL
When L switches from the first reception frequency to the second reception frequency,
It has a finite rising transient oscillation process time. The finite rising transient oscillation process time is the switching time ti
The following must be taken into account in the calculation of ## EQU1 ## that the PLL has already been switched to the alternative frequency at time t1, so that at time t1 the reading of the data samples starts on time. You have to consider it. Accordingly, the switching time ti from the original frequency or the current frequency 18 to the alternative frequency 19 must be shifted at least before the read-in time ti by the duration of the rising transient oscillation process of the PLL (indicated by reference numeral 53 in FIG. 3). Must. As shown in FIG. 3, the entire duration Tu of the interruption of the reception of the original frequency or the current frequency indicated by reference numeral 53 in the drawing is as follows.

Tu = 2 × T _E + T _V , where T _E is the rising transient oscillation duration of the PLL.

In a first embodiment of the method according to the invention, the switching of the frequency from the original frequency or the current frequency 18 to the alternative frequency 19 is shifted forward with respect to the time point ti by a coherent, assumed duration T _E. Or not, hasten.
Here the assumed rising transient oscillations duration T _E where a cohesive that collectively which are settings of the PLL, corresponds to the maximum rising transient oscillations duration, the maximum rising transient oscillations duration over a maximum frequency range In the case of all frequency jumps, ie, between two transmission frequencies located at opposite frequency ends of the FM frequency band. Said maximum rising transient vibration duration T _E
By means of a shift or an early shift before only the switching time point, the PLL has already been switched to the alternative frequency before the reading time point t1 with a jump smaller than the maximum frequency jump. In such a situation, it is necessary to monitor the arrival at time t1 in order to guarantee the reading of the data sample at time t1.

In the second embodiment of the method according to the invention, the rising transient duration TE, which, as already mentioned, depends on the width of the jumped frequency range, is determined by the original or current frequency and the alternative frequency. it is calculated from the difference between the values, and is being shifted before separately calculated the rise transient oscillations duration T _E of the PLL with respect to the read time ti. Thereby, the PLL is in a steady state, switched to the alternative frequency at the beginning of the data sample acquisition in a timely manner, while the interruption duration 53 takes on the minimum possible value when receiving the original or current frequency. .

FIGS. 4A and 4B respectively. Examples of the contents of the generation memory or the contents of the result register are shown. The contents of the result register-the result register has a length of 104 bits like the intermediate register-is obtained in this case by adding the contents of the intermediate register. Here, the value of o, ie, the number of bit groups to be evaluated, and thus the number of intermediate registers in the memory 4, is selected to be four. The basis for the following discussion is that the value of the logic "1" of the digital signal is mapped to the value "1".

Based on the fact that the various groups taken of the data samples have at least in part different group types and thus different contents (FIG. 4a), the extreme values, ie the maximum and the minimum, are Occurs only in the result registers where the following information is stored: firstly common to all group types, and secondly, regardless of group type, within each group Occurs only at the location where the information transmitted at the same position is stored. This is illustrated in FIG.
a, on the one hand, is a PI 40, which is transmitted in block A of each group, in this case detected in data samples 70 and 71, and
As part of block 26 are TP41 and PTY42, which have been read with data samples 65 and 66. Furthermore, the minimum and maximum values in the area of data samples 72 and 65 in the form of superimposed words consisting of the control and offset words of block A25 are shown. The minimum and maximum values are based on the following: for each group, under the same content of block A, the control word calculated from the information words has the same value per group; Furthermore, the PI is transmitted in block A in each group, so that for each group the superimposed word consisting of control and offset words for block A has the same value. Further, as is apparent from FIG. 4A, in the areas of the blocks B26 and D28, values fluctuating around the arithmetic average of the extreme values are generated. This results from the fact that data is collected from various group types, and thus the basis for the distribution of the bit positions of the signals in which different information is transmitted per group. Arising from

FIG. 4b shows the contents of the result register for the case where all data samples have been extracted from different types of groups. In this case, other data of groups having different information contents under different group types can also be used.
Further, FIG. 4B shows intermediate values 80, 81, 8 in addition to the extreme values.
2 are also shown, these intermediate values being caused, for example, by errors in the transmission of digital signals.

The determination as to whether an individual bit value should be considered as an extremum or an outlier from the statistical mean or as an extremum can be made, for example, by an extremum around each value and the value considered. This is possible by synergistic consideration of the frequency of deviation from

FIGS. 5a and 5b show the sequence of the method of the present invention, which is implemented, for example, in software in the control unit 5 of the broadcast receiver of the present invention. The sequence starts at step 100. In step 110,
The RDS demodulator 3 of the broadcast receiver of the present invention is synchronized with the digital signal of the alternative frequency. This is done as follows, as shown in FIG.
In step 1, the receiver 2 is adjusted or tuned from the original frequency or the current frequency to the alternative frequency using the PLL.
In step 13, the detection of the start of the bit is checked, and step 1
After the detection of the beginning of the bit at 14, the detected time of the beginning of the bit is stored for calculation of a further switching time ti and a time t1 for data sample extraction, and further at step 115 the receiver 2 resets the PLL. It is used to return to the original frequency or the current frequency from the alternative frequency and adjust or tune. In step 120, besides further calculations after the bit synchronization of the RDS signal demodulator, the dwell duration TV is determined by the group duration TG and the quantities m and p.
And the next switching time ti from the original or current frequency to the alternative frequency is calculated taking into account the rising transient oscillation duration TE of the PLL. After reaching the switching time ti, which is checked in block 130, the receiver 2 of the broadcast receiver is adapted in block 140 from the original or current frequency to the alternative frequency. At block 160 At block 150, as long as it reaches the read time t1 calculated at block 120, one bit is read in at step 170, the residence time T _V on the alternative frequency has already elapsed Is checked, and unless so passed,
The next bit of the digital signal is read at step 160. If the dwell time on the alternative frequency has passed as a result of the check in step 170, in other words, if all bits of the actual data sample have been detected, the receiver 2 of the broadcast receiver returns to step 180 in step 180. The frequency is returned from the alternative frequency to the original frequency or the current frequency and adjusted. Subsequently, at step 190, it is determined whether sufficient data samples are already available for evaluation.
That is, it is checked whether the boundary condition oxm has been reached. If not, the method process proceeds to step 120, i.e., to calculate a new dwell time T _V up to the next read time ti for the next data sample extraction. On the contrary, when the aforementioned boundary is reached, when the aforementioned boundary condition is reached, that is, when all the intermediate registers of the memory 4 are occupied by the newly collected data, the evaluation in step 200 is as follows. In other words, FIG.
a, as in the example of FIG. 4-b, the contents of the intermediate registers are added, the result register contents are provided to a limit value determiner, and further data derived from the limit value determiner as useful is further provided. It is supplied to a processing unit, for example, a PI-evaluation unit. The method ends at step 210.

In a further embodiment of the method according to the invention, the evaluation of the read signal can also be performed as follows: new data is collected in the second register and the contents of the first register and They are combined, and the result is subsequently returned to the same register and written again.

[0036]

According to the present invention, DE-A-41030
Due to the shorter switching from the actual transmission frequency to the frequency to be checked compared to the known broadcast receiver from 61,
This has the effect that the audible audio signal interruption made during the switching is not audible, and also saves the cost for recording the audio signal section preceding the interruption as in the prior art. .
It also has the effect that the alternative frequency is relatively less time critical, so that the phase control loop for frequency switching has less requirements to be fulfilled, and furthermore a disturbing click noise-this For example, in the alternative frequency, an effect that is caused by transmitting a modulated wave different from that in the original frequency is avoided.

[Brief description of the drawings]

FIG. 1 is a block diagram of a part important to the present invention of a broadcast receiver for implementing the method of the present invention;

FIG. 2 is a signal configuration diagram showing a configuration of a digital signal transmitted using RDS.

FIG. 3 is a signal configuration diagram for clarifying the sequence of the method of the present invention.

FIG. 4 is a signal configuration diagram of a generated group formed by averaging a plurality of received groups.

FIG. 5 is a sequence flowchart of software implemented by a control unit of the broadcast receiver.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Receiving antenna 2 Receiver 3 RDS signal demodulator 4 Memory 5 Control unit 6 Mute circuit 7 Regeneration circuit 18 Original frequency or current frequency 19 Alternative frequency 20 Data- (RDS-) signal 21 Bit group 22 Bit group 23 Bit group 25 block 26 block 27 block 51 PLL 52 group duration, group leader 53 total duration Tu, interrupted 65 the data group 66 the data group 70 data samples 71 data samples 72 data samples 80 intermediate value 81 intermediate values 82 sustained intermediate value T _B 1 bit Time _TG group duration T _I interval duration T _v Dwell duration

Continued on the front page (72) Inventor Dieter Bombka Hildesheim las Temburger Strasse 6 (72) Inventor Klaus-Erwin Greiger Germany

Claims (4)

[Claims] 1. A method for evaluating a data signal (20), for example, an RDS signal, said signal comprising, in parallel with a broadcast program, a bit group (21,
22 and 23), transmission is performed at another transmission frequency (19) different from the transmission frequency (18) actually adjusted at the receiver, where the reception frequency of the receiver is first adjusted at the adjustment setting. From the set frequency to another frequency (19) repeatedly and temporarily, where the receiver remains at said other frequency (19) or is received during the dwell time In this evaluation method, wherein the bits of the digital signal (20) transmitted at the other frequency are read and temporarily stored, the repeated temporary switching (56 to 60) is performed at the time interval (5 to 60).
4), and the length of the time interval (54) is set to an integral multiple of the group length (52), and the other frequency (1) is set.
9) The bits of the digital signal (20) read during the temporary switching (56-60) correspond to the length of the dwell time (50) plus the above, and the evaluation cycle (200) A method for evaluating a digital signal, characterized in that the evaluation is performed in (1). 2. The temporary switching (56 to 60) is repeated many times until an integer multiple (0) of the bit group is temporarily stored, and the bits of the generated bit group set for evaluation are temporarily stored. 2. A method according to claim 1, characterized in that it is formed by averaging the bits of the group of bits that has been set. 3. Only a block of the generated bit group is supplied to the estimator, the bits of which are received as multiplexed based on averaging and as identical over and over, 3. The method according to claim 2, wherein only blocks of the generated bit groups that are reliably identified are supplied to the evaluator. 4. The method according to claim 1, wherein the reproduction of the received program is interrupted during the switching of the receiver to another transmission frequency. A method according to any one of the preceding claims.