CZ369792A3 - Transmission method of a time-varying manipulated variable - Google Patents

Description

Method of transmission of time-variable action variable

Technical field

The invention relates to a method of transmitting a time-varying action variable which is derived from an associated radio program signal and transmitted together with a program signal to be used on the receiver side to select reproduction dynamics different from the transmitted dynamics of the program signal. a digital additional signal at intervals into the data stream as a data packet that is transmitted in the transmission band region of a radio program signal that is free of program signals asynchronously to the program signal.

BACKGROUND OF THE INVENTION

Such a method is known from EBU Review-Technical, No. 218 (August 1986) pages 2-12.

Radio signals are fed to transmitters with dynamics (the difference between the loudest and quietest signals), which is tuned to the signal-to-noise ratio of the next transmission path. In many cases, however, the resulting dynamics does not correspond to the individual wishes of radio listeners. For example, when listening to a radio in a moving motor vehicle, the transmitted dynamics are too high in relation to the noise level in the vehicle, while, for example, when listening to headphones, the transmitted dynamics, which are generally smaller than the original dynamics of the recorded audio signal.

In order to significantly improve the reproduction of the audio signals, it is desirable that the dynamics be adapted to the location of the listener's wishes. It is known for this purpose (EBU

Review-Technical, No. 218, August 1986) derive from the program signal an action variable that represents the concentration of the original dynamics to the so-called target dynamics. By target dynamics is meant a narrowing or concentration to a certain value, for example 30 dB, that is less than the transmitted dynamics. This action signal is transmitted synchronously with the associated program signal and evaluated in the receiver for a variable dynamics selection. The free choice of dynamics is made possible by the target dynamics being carried out or by further narrowing (motor vehicle) or by reversing the use of the action signal to reconstruct the original dynamics by means of the transmitted action variable.

For the transmission of an action signal, variable dynamics is known (DE-PS 33 11 646 and DE-PS 33 11 647) to the lower end of the frequency

The S-signal of an M / S-coded stereo audio signal is to insert an inaudibly one fixed and one variable, low-level audio frequency whose frequency spacing is a momentary action variable. The narrowband filters required for demodulation do not allow rapid variations in frequency difference, but action variables; furthermore, the frequency range in the S-signal, adapted to transmit the action signal, is not fault-free enough to guarantee a safe transmission with the lower audio signal levels used. Especially in the case of mobile reception, disturbances due to multipath reception occur in the respective frequency range.

Due to these serious shortcomings, the digital transmission of the action signal requires variable dynamics in the region of the transmission band of the radio signal, which is free of program signals. For a television audio signal, the area of the image element suppression already used for other digital additional signals (teletext) would be considered as the area without program signals. For the UKW-FM signal, a sub-carrier in the multiplex channel is offered; however, there is a problem that as early as 57 kHz traffic intelligence identification signals as well as the radio data system (RDS) data flow are transmitted and other auxiliary carriers cannot be accepted due to the decoder cost on the listener receiver side. However, the insertion of the variable dynamics action signal into the RDS data stream or the teletext data stream is an obstacle to the fact that these data streams can be transmitted synchronously with the UKW- or television audio signal, which is not compared to the requirement for synchronous transmission of the variable dynamics.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method of transmitting an action signal of variable dynamics which, through asynchronous transmission of the data stream, guarantees the necessary synchronization between the action signal and the program signal.

SUMMARY OF THE INVENTION

This task fulfills a method of transmitting a time-varying action variable that is derived from an assigned radio program signal and is transmitted together with a program signal to be used on the receiver side to select reproduction dynamics different from the transmitted dynamics of the program signal in which the action variable is entered as a digital access signal at intervals into the data stream as a data packet which is transmitted in the transmission band region of a radio program signal which is free of program signals asynchronously to the program signal according to the invention, which is that the varying time difference between the times of inserting data packets in intervals and the formation of the respective program signal sections is a special time information They are transmitted in data packets and used on the receiver side to synchronize the advance action signal with the program signal.

According to a preferred embodiment of the invention, a plurality of typical action signal waveforms are fixed on the receiver side and that only the fixed action signal waveform addresses are transmitted as action signals.

According to a further preferred embodiment of the invention, additionally, the action signal values actually generated at the boundaries of the program signal sections are transmitted together with the fixed signal address addresses which are used on the receiver side for sense testing and / or correction and / or program or action signal failure.

In this case, it is advantageous if the digital additional signal is inserted into the data stream of the radio data signal (RDS signal), which is transmitted on the auxiliary carrier in the multiplex channel of the FM program signal.

Further is . advantageous when. a periodically repeating sequence of data bits (groups) for transmitting the action signal is formed in the RDS data stream, and that a plurality of groups are created in the RDS data stream, and that only such groups are transmitted that are occupied by the digital accessory data packet signal.

In this case, it is advantageous if the sequences of data bits (groups) in the RDS data stream are always inserted between the other groups as necessary to store the digital access signal data packet.

According to a further preferred embodiment of the invention, on the receiver side, the digital additional signal is separated from the data stream and evaluated. In this case, it is advantageous that, during the evaluation period t (delta t), the information contained in the data packet which is used to control the memory (23) for the action signal is variable dynamics.

The method according to the invention is based on the consideration that the variable dynamics action signal does not leave the broadcast studio simultaneously with the program signal, but with a constant advance, for example 1000 ms. This advance allows the following way, explained according to the RDS data stream:

The RDS encoder in the transmitter receives the action signal and stores it.

Once the RDS-encoder has a free group (sequence) of data bits, the digitized action signal is transmitted in this group as a data packet. The 37 pure bits available in one group could be used as follows:

bits to transmit the variable of action variable dynamics, bits to indicate the time of transmission.

The last 5 bits indicate how many ms (microseconds) the transmission in the RDS encoder is always delayed or how many lead times were consumed. This allows the receiver to:

- re-align the data packet and convert it into discrete action signals at constant time intervals, so that a constant action data flow is finally created, and

- further delay this data in a simple shift register so that the entire lead time is equalized and a constant action data flow is again synchronized with the program signal.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a device for carrying out the method of the invention adapted on the transmitting side; FIG. 2 is a block diagram of a device for carrying out the method of the invention adapted on the receiving side; 3 is a block diagram of an apparatus for carrying out one variant of the method according to the invention, modified from the apparatus of FIG. 2, and FIGS.

DETAILED DESCRIPTION OF THE INVENTION

The apparatus for carrying out the method according to the invention, arranged on the transmitting side, shown schematically in FIG. 1, consists of a radio studio 10, in which the program signal 11 and the action signal 12 are variable dynamics. The action signal 12 is derived from the program signal 11, as already mentioned above. Essentially, a time delay of the program signal 11 relative to the action signal 12 is performed on or before exiting the radio studio 10, which is symbolized in FIG. 1 by a time element 13 with a constant delay time. This delay causes the action signal 12 to be ahead of the associated program signal section 11.

In Fig. 4a, for the received time course of the radio program signal 11, three of its sections n, n + 1 and n + 2 are shown having the same time lengths. From each segment of n or n + 1, a variable dynamics action signal 12 is derived, for example, in the form of discrete sensing values. The read values for each segment of the program signal 11 are summarized in digital form into a data packet, as shown in FIG. 4c, and at the moment of the last read value the associated data packet begins in the example shown.

As further shown in FIG. 1, both the program signal 11 and the action signal 12 are transmitted via separate lines 14 and 15 to each other.

The transmitting station 16 consists, in the illustrated embodiment, of a UKW-FM transmitter 17 and an RDS encoder 18. wherein the program signal 11 is fed to the transmitter 17 and the advance signal 12 to the RDS- encoder .18. The RDS-encoder 18 inserts the data packets of the action signal 12, delayed by the variable delay time Att, into its RDS data stream, as will be further elucidated in Figs. 4d and 4f and 4g, respectively.

In the variant of FIG. 4d, the data stream stored in the RDS-encoder 18 comprises a cyclic sequence of groups in which the VD groups for the insertion of the action signal 12 are already provided with variable dynamics. The cycle shown in FIG. 4d comprises the groups OA, VD, 2A, OA, VD, 6A, OA, VD, 6A, 2A, OA, VD, 6A, and 6A. The interleaving of the data packets of the action signal 12 associated with the regions n, n + 1 and n + 2 of the program signal 11 is shown in Fig. 4e. In the transmitted RDS data stream, some of the VD groups kept free for insertion of the action signal 12 are dropped if no data packets to be inserted are available for these VD groups. In the example of FIG. 4d, this means that the VD groups with sequence numbers 2 and 5 are not transmitted, so that at the time the considered data packet of sequence number n originates, the data packets 1, 3, 4 and 6 are already transmitted, respectively. No. 6) is in broadcast.

The next free group VD is therefore group # 8, so it is necessary to wait for the data packet n to be inserted until group # 7 is completely transmitted. This waiting time or pause is indicated in Fig. 4e as At _n> The same considerations apply to data packets with the sequence numbers n + 1 and n + 2, in which case the pauses are designated as At _{n + 1} and Át _{n + 2 respectively.} . As can be seen from the plots, these delays are different with respect to the structure of the stored RDS data stream, and at most can be the distance between two consecutive VD groups. Due to the respective delay Att, the advance of the action signal 12 is reduced to the value of T-tt relative to the portion of the associated program signal 11. Since the program signal 11 and the action signal 12 must be synchronized in the receiver, the delays At are collected and transmitted in the RDS encoder 18 encoded in the respective data packet.

The transmitted RDS data stream is fed from the RDS encoder 18 to the transmitter 1/7, where it is transmitted according to the standard to an auxiliary carrier in the multiplex region of the program signal 11.

As an alternative to activating the VD groups in the stored sequence of RDS data groups, it is possible to dispense with such activation as shown in Fig. 4d and 4f according to Fig. 4f. The advantage is that the group sequences (cycle) stored in the RDS encoder 18 are considerably shorter than in the case of Fig. 4d. If a data packet is to be inserted into the stored sequence of RDS data groups according to FIG. 4f, this insertion is performed at the end of the currently transmitted group, the next cycle group being shifted by the duration of one group. As shown in Fig. 4g, the insertion of the data packet n at the end of the group with sequence number 4 in cycle 1, the data packet n + 1 at the end of the group with sequence number 7 in cycle 2 and the data packet n + 2 at the end of the group with sequence number 9 in cycle 2. This also produces delays At _n , At _{n + 1} or tt _{n + 2} , which, however, are considerably shorter than those of FIG. This represents a further advantage of the alternative of Figures 4f and 4g.

In the apparatus provided on the receiving side schematically shown in FIG. 2, in a receiver capable of receiving RDS signals, the transmitted RDS data stream is separated from the radio program signal 11 and fed to the RDS decoder 21 which demodulates the transmitted RDS data stream; decodes. The decoded RDS data stream is passed to step 22 (which may also be part of the decoder 21), where the variable dynamics is separated and evaluated by the action signal 12. In this case, the information contained in each data packet is recovered during the dwell time tt, which then serves to control the following buffer 23 of the action signal 12 variable dynamics. The action signal 12 generated at the output of the buffer 23 is again synchronous with the associated segment of the program signal 11 which is fed from the receiver 20 to the controlled amplifier 24. The same time signal 12 on the control output of the regulated amplifier 24 varies according to the manual input 25 setting. amplifier 24 to amplify the program signal 11, so that the program signal 11, reproduced by the speaker 26 or headphones (not shown), has the dynamics corresponding to the individual wish of the listener or the manual default value at input 25. way than on the transmitter side.

FIG. 3 shows a further embodiment of the receiver-side device, taking into account that only a limited capacity is available for the transmission of the action signal 12 in one RDS transmission channel. However, in order to guarantee transmission in the data protection RDS channel, instead of the buffer 23 shown in FIG. 2, a memory 27 is provided on the receiver side in which the typical action signal waveforms 12 are stored firmly. then they transmit only the addresses of the respective desired action waveforms 12, whereby the channel capacity is much less utilized than when transmitting the action waveforms 12 as such.

program signal 12,

In addition to the addresses of the fixed action waveforms 12, the actual action values generated in the memory 27 can be transmitted at the boundaries of the signal sections 11 and used in the memory 27 for plausibility and / or correction and / or initiation or in the event of a failure of the action signal 12. The capacity savings achieved by this alternative method of the invention are so great that each data packet can be transmitted twice in the RDS data stream, which, of course, means a significant increase in the security of transmission.

Below the block showing the memory 27, FIG. 3 shows typical action waveforms 12:

Pitch line 0 (constant dynamics) Positive line (increasing dynamics) Negative climb line (decreasing dynamics) signal jumps with different amplitude, direction and time (significant dynamics changes according to size, direction and time) .

Claims (8)

PATENT CLAIMS 1. A method of transmitting a time-varying action variable that is derived from an assigned radio program signal and transmitted together with a program signal to be used on the receiver side to select a reproduction dynamics different from the transmitted dynamics of a program signal in which the action variable is inserted as digital an additional signal to the data stream in intervals as a data packet which is transmitted in the transmission band region of a radio program signal which is free of program signals asynchronously to the program signal, characterized in that the insertion of the digital additional signal is effected in advance that the varying time difference between the times of inserting data packets in intervals and the occurrence of the respective program signal sections is transmitted as special time information in the data pa ketech and receiver side are used to synchronize the advance action signal with the program signal. Method according to claim 1, characterized in that a plurality of typical action signal waveforms are fixed on the receiver side and that only the fixed action signal waveform addresses are transmitted as action signals. Method according to claim 2, characterized in that additionally the action signal values actually generated at the boundaries of the program signal sections are transmitted together with the fixed signal address addresses which are used on the receiver side for sense testing and / or correction and / or to initiate power-up, in the event of a program error or failure of the action signal. Method according to one of Claims 1 to 3, characterized in that the digital additional signal is inserted into the data stream of the radio data signal (RDS signal) which is transmitted on the auxiliary carrier in the multiplex channel of the FM program signal. Method according to claim 4, characterized in that periodically repeating sequences of data bits (groups) for transmitting the action signal are created in the RDS data stream, and that a plurality of groups are created in the RDS data stream, and broadcast only those groups that are occupied by the digital accessory data packet. Method according to claim 4, characterized in that the sequences of data bits (groups) in the RDS data stream are each inserted between further groups to store the data of the digital additional signal as needed. Method according to one of Claims 1 to 6, characterized in that on the receiver side the digital additional signal is separated from the data stream and evaluated. Method according to claim 7, characterized in that the information contained in the data packet which is used to control the memory (23) for the action signal variable dynamics is retrieved during the delay time At (delta t). /