AU655588B2 - Process for transmitting a time-variable control parameter - Google Patents

Description

OPI DATE 23/01/92 AflJP flATIZ 97/ n,?/109 APPLN. ID 80059 91 INTEI ER DIE I NTERriuiAi jUjiNPXLZ .)Jr VjlNJ1~~ 1A~JJA S (PCT) (51) Internationale Patentklassifikation 5 (11) Internationale Ver~iffentlichungsnummer: WO 92/00637 H04H 1/00, H03G 7/00 Al (43) Internationales Veriiffentlichungsdatum: 9. Januar 1992 (09.0 1.92) (21) Internationales Aktenzeichen: PCT/EP9I/01202 (74) Gerneinsamer Vertreter: TELEFUNKEN FERNSEH UND RUNDFUNK GMBH; Patent- und Lizenzabtei- (22) Internationales Anmeldedatumn: 26. Juni 1991 (26.06.9 1) lung, G6ttinger Chaussee 76, D-3000 Hannover 91 (DE).

Prioritaitsdaten: (81) Bestixnmungsstaaten: AT (europtiisches Patent), AU, BB, P 40 20932.6 30. Juni 1990 (30.06.90) DE BE (europ~isches Patent), BF (OAPI Patent), BG, BJ (OAPI Patent), BR, CA, CF (OAPI Patent), CG (GAP! Patent), CH (europ~isches Patent), CI (OAPI Patent), (71) AImelder al ame US). TELL-- CM (OAPI Patent), CS, DE (europ~isches Patent), DK 1 VUNICEN Q 44-Mlh N "'P T 1 Y .M3A (eurcpdisches Patent), ES (europtiisches Patent), Fl, FR I'DE'DE, C1atss 76, D ;0909 liaai 91 (europgisches Patent), GA (OAPI Patent), GB (europdi- '(DE).sches Patent), GN (OAPI Patent), GR (europhisches Patent), HU, IT (europiiisches Patent), JP, KP, KR, LK, (72) Erfinder; und LU (europaisches Patent), MC, MG, ML (QAPI Patent), Errinder/Anmelder (hur fdr US) :MIELKE, Jorgen [DE/ MN, MR (QAPI Patent), MW. NL (europhisches Pa- DE]; Floriansm~hlestr. 70, D-8000 Mtinchen 45 tent), NO. PL, RO, SD, SE (europaisches Patent), SN PLENGE, Georg [DE/DE]; Hauptstr. 26A, D-8191 (OAPI Patent), SU, TD (OAPI Patent), TG (OAPI Pamhanning tent), US.

Veriiffentlicht A4't internationalem Rclerclienbcricli.

(54)Title: PROCESS FOR TRANSMITING A TIME-VARIABLE CONTROL PARAMETER (54)Bezeicbnung: VERFAHREN ZUM OBERTRAGEN EINER SICH ZEITLICH XNDERINDEN STELLGROSSE R I~ j PARAWRtN 3 M oAAAA r srrcl r- s~risrA -tA497A 11IAW SIOAI Prcgrwn,-+ Pr'tr m "VT abscloift n A ttri A. h ProgramrsiqnA A"1~ SMAIuv.

Eq Iq Eq A PACACTA IA A STNE.M AIAA FIS MU1A 1 A~S nl n-1 n,2 UOZ dJ4&dJ IIATA SWIAM .rA.EW IN AM. CQ0l ASCi cycIM ScIIL 3 1 t -4 061~ -J Wi4* 16 21 11 1 1,M 21 ENY IIIVI SIIAASA'TL -A A6AV 6DA 04lk6A0 1 n-1 Stdisignale OW1AQA G1A RA ge~rtertensro n n.1 n-Z geendelAI Dateisftrem 4 4 A'1 OAJ O 2 A1 dJ 12 OA t VMS Eod Zyliis 1 Zyl~us 2 Zyklus 3 _i -4 IAt-n 1 W_?~n A 6AOA6Aj\/QUA0%&A DUX'A 1ju ZylIIA2geserdieter RDS-Dalensirom~ (57) Abstract For individual tuning of the dynamics of a radio programme signal (variable dynamics), a control parameter is derived from the associated radio programme signal and emitted together with the programme signal. At the receiver, the control signal is used to select reproduction dynamics differing from the transmitted programme-signal dynamics. For transmission purposes, the control parameter is inserted as a digital auxiliary signal in a data stream which is transmitted asynchronously to the programme signal in a programme-signal-free region of the transmission band. The digital auxiliary signal is inserted at intervals as a data packet with varying advance with respect to the program me-si gnal section concerned. The variable time differences between the points in time at which the data packets are inserted and the occurence of the programme-signal sections are transmitted as separated time information in the data packets and used at the receiver to synchronize the advanced control signal with the programme signal.

vi WO 92/00637 1 PCT/EP91/01202 Process for Transmitting a Time-variable Control Parameter

DESCRIPTION

The invention relates to a process (method) according to the preamble of patent claim 1. Such a process is known from the "EBU Review-Technical", No. 218 (August 1986), pages 2 through 12.

Radio broadcast audio signals are fed to the transmitters with a dynamic (difference between the loudest and quietest signals) which is adapted to the signal-tonoise ratio of the subsequent transmission path. However, the dynamics resulting from this in many cases does not correspond to the individual wishes of the radio listener.

Therefore, for example, when listening in a vehicle while it is moving, the transmitted dynamic is much too large owing to the noise level in the vehicle, whereas, for example, when listening via headphones, the transmitted dynamics, normally lower then the original dynamics of the recorded acoustic signal, is too low.

In order to markedly improve the reproduction of the audio signal, it is desirable to be able to adapt the dynamics individually at the place of reproduction to the wishes of the listener. For this, it is known ("EBU Review- Technical", No. 218, August 1986) to derive a control parameter (manipulated variable) from the program signal REPLACEMENT SHEET L~ 1 WO 92/00637 2 PCT/EP91/01202 which then represents the restriction of the original dynamics to a so-called "target dynamic". "Target dynamic" is understood to be the restriction to a certain value, for example, 30 dB, which is less than the transmitted dynamics.

This control signal is transmitted sychronized with the associated program signal and evaluated in the receiver for the variable dynamics selection. The free choice of dynamic is rendered possible in that the "target dynamic" is realized with the aid of the transmitted control parameter or is further constricted (vehicle) or the original dynamics is recreated through inverse utilization of the control signal.

For transmitting the "variable dynamics" control signal it is known (DE-PS 33 11 646 and DE-PS 33 11 647) to insert, inaudibly, a fixed and a variable audio frequency with low level at the lower frequency end of the S signal of an M/Scoded stereophonic audio signal, whereby the frequency separation of said frequencies represents the current control parameter. However, the narrow-band filters necessary for the demodulation of the frequency separation do not allow rapid alterations to the control parameter; further, the frequency range in the S signal provided tor the transmission of the control parameter is not sufficiently interference-free in order to guarantee a reliable transmission with the small signal levels used for the audio frequencies. In particular, interference in the frequency range concerned occurs through multipath reception in the case of mobile reception.

Owing to these serious defects, a digital transmission of the "variable dynamics" control signal is desirable in a region of the transmission band of the broadcast signal which is free from program signals. For the case of a television sound signal, for example, the blanking region of the picture signal, already in use for other digital U1REPLACEMENT SHEET 0~ 1?- WO 92/00637 3 PCT/EP91/01202 auxiliary signals (videotext), could be considered as the region free from program signals. An auxiliary carrier in the multiplex channel offers itself for an FM signal; however, there is the difficulty here that already the identification signals for traffic program broadcasts as well as the data stream for Radio Data System (RDS) are transmitted at 57 kHz, and other auxiliary carriers are not acceptable to the radio broadcast subscriber owing to the expanditure relating to the decoder on the receiver side.

However, inserting the "variable dynamics" control signal into the RDS data stream or the videotext data stream respectively is is not possible because these data streams are not broadcast Eychron-ie4with the FM audio or television sound signals respectively, something which runs counter to the requirement for a synchronized transmission of the "variable dynamics" control signal.

process for transmitting the "variable dynamics" control signal which, despite non-synchronized data stream transmission, guarantees the necessary synchronization between the control variable and the program signal on the receiver side.

This task is solved according to the inventio by the characterizing features of patent claim 1.

Embodiments and further development of the process t according to the invention ensue frm he subclaims.

The process according to e invention is based on the consideration that the "v lable dynamics" control signal is not isochronous with t program signal but, on the contrary, leaves th broadcasting studio with a constant advance of, for xample, 1000 ms. This advance permits the following me tod of functioning, explained by means of an RPAE data Eeam.S REPLACEMENT

SHEET

3a The present invention consists in a process for transmitting a time-variable control parameter which is derived from an associated radio broadcast program signal and is broadcast together with the program signal in order to be used, by a receiver, for the selection of a reproduction dynamic which can deviate from a transmitted program signal dynamic by being individually adapted during reproduction by the receiver to suit the wishes of the listener, in which the control parameter is a digital auxiliary signal which is inserted as data packets at intervals into a data stream which is transmitted in a program signal-free region of a transmission band of the radio broadcast program signal and the data packets being non-synchronized with the program signal wherein each o 15 control parameter is related to a segment of the program signal and that the insertion of the digital auxiliary 00oo signal is carried out with a varying advance with respect °oooo to the related program signal segment and that a measure for the related variable advance is transmitted as a separate tme information in each data packet and used, by the receiver, for synchronizing the control parameter with o the program segment.

o The process according to the invention is based on the consideration that the "variable dynamics" control °0 25 signal is not isochronous with the program signal but, on 0 the contrary, leaves the broadcasting studio with a constant advance of, for example, 1000 ms. This advance permits the following method of functioning, explained by means of an RDS data stream.

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f-, WO 92/00637 4 PCT/EP91/01202 The RDS coder at the transmitter receives the control signal and stores it. As soon as the RDS coder has a free group (sequence of data bits) available, the digitalized control signal is transmitted as a data packet in this group. The 37 net bits available in one group could be used as follows: 32 bits for the transmission of the "variable dynamics" control parameter bits for the identification of the time of transmission.

The latter 5 bits specify by how many milliseconds the transmission has been delayed in the RDS coder or, respectivelyr how much of the advance t-me has been 'consumed". This information allows the receiver to: temporally deaccontuate the data packet again and convert it into individual discrete control signals with constant temporal separation so that a constant control data stream results at the end, and further delay these data in a simple shift register in such a way that the entire advance time is compensated, and the constant control data stream is again available, synchronized with the program signal.

The invention will be explained in more detail by means of embodiment examples illustrated in the drawings. They show in: Fig. 1 a block circuit diagram of an installation on the transmitter side for executing the process according to the invention; ZREPLACEMENT SHEET rEta d

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WO 92/00637 5 PCT/EP91/01202 Fig. 2 a block circuit diagram of an installation on the receiver side for executing the process according to the invention; Fig. 3 a block circuit diagram of an installation, modified compared to Fig. 2, for executing a variation of the process according to the invention, and Figs. 4a through 4g diagrams for illustrating individual steps of the process according to the invention.

The installation for executing the process according to the invention on the transmitter side, illustrated schematically by means of Fig. 1, shows a radio broadcast studio 10 in which a radio broadcast program signal 11 and a "Variable Dynamics" control signal 12 are generated. The control signal 12 is here derived from the program signal, as already explained above. The essential factor is that at, or respectively, prior to the output from the studio a temporal delay of the program signal 11 with respect to the control signal 12 is carried out, indicated in Fig. 1 by a time function element 13 with a constant delay time. This delay leads to the control signal 12 being in advance of the associated program section of the program signal 11. In Fig. 4a, three program sections n, n+l and n+2, each having the same temporal length, are plotted for an assumed time sequence of a radio broadcast program signal. The "Variable Dynamics" control signal is derived, for example, in the form of discrete scanning values, from each program section n or n+l respectively. The scanning values for each program signal segment are, as Fig. 4c shows, combined in a digital form into a data packet, whereby, at the time of the final scanning value, the associated data packet begins in the example presented.

CbI RE PLACEMENT SHEET 0 I:.

WO 92/00637 6 PCT/EP91/01202 As also follows from Fig. 1, the program signal 11 and the control signal 12 are transmitted to the transmitter location 16 via separate lines 14 and 15 respectively. The transmitter location 16 comprises, in the example presented, an FM transmitter 17 as well as an RDS coder 18, whereby the program signal 11 is sent to the transmitter 17 and the advanced control signal 12 is sent to the RDS coder 18. The RDS coder 18 inserts the data packets of the control signal 12, delayed by a variable time A(delta) T, into its RDS data stream, as is to be explained in more detail in the following by means of Figs. 4d and 4e or 4f and 4g respectively.

With the variation according to Fig. 4d, the data stream stored in the RDS coder 18 contains a cyclic sequence of groups in which groups VD for inserting the "Variable Dynamics" control signal are already provided. The cycle illustrated in Fig. 4d comprises the groups OA, VD, 2A, OA, VD, 6A, OA, VD, 6A, 2A, OA, VD, 6A and 6A. The insertion of the data packets of the control signal allocated to the program segments n, n+l and n+2 is shown in Fig. 4e. In this case some of the groups VD in the transmitted RDS data stream reserved for the insertion of the control signal are omitted if no data packets are present to be inserted for these groups. This means, in the case of the example according to Fig. 4d, that the groups VD with the current group numbers 2 and 5 are not transmitted so that at the time of the appearance of the data packet under consideration for the current number n, the data packets 1, 3, 4 and 6 have already been broadcast or, respectively, (data packet No. 6) are just being broadcast. The next free group VD is, therefore, group No. 8 so that the insertion of data packet n must wait until group No. 7 has been broadcast completely. This waiting time is designated Atn in Fig. 4e.

The same considerations apply to the data packets with the current numbers n+l and n+2, whereby in this case the REPLACEMENT SHEET Ii- Q 0Zi..

'21 t

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7 4 WO 92/00637 7 PCT/EP91/01202 waiting times ares designated Atn+ 1 and Atn+ 2 respectively.

As one can see by means of the waiting times plotted, the waiting times are different owing to the structure of the stored RDS data stream and can have, as a maximum, the separation between two successive groups VD. As a result of the respective waiting time At, the advance of the control signal 12 is reduced, with respect to the associated program signal segment, to the value t/tau) -At. As the program signal and the crtrol signal need to be synchronized in the receiver, the waiting times At are recorded in the RDS coder 18 and transmitted in coded form in the data packet concerned.

The transmitted RDS data stream is fed from the RDS coder 18 to the transmitter 17 where it is transmitted on an auxiliary carrier in the multiplex region of the program signal according to the standard.

As an alternative to providing groups VD in the stored sequence of RDS groups, it is also possible, according to Fig. 4f, to do without such a provision, as is quite clear from comparing Figs. 4d and 4f. One advantage of this is that the sequence of groups (cycle) stored in the RDS coder 18 is considerably shorter than is the case in Fig. 4d. If a data packet is to be inserted into the stored sequence of RDS groups according to Fig. 4f, then this insertion is performed at the end of the group just sent, whereby the next group in the cycle is displaced by the duration of one group. As Fig. 4g shows, the insertion of the data packet n is carried out at the end of the group with the current number 4 in the cycle 1, data packet n+l at the end of the group with the current number 7 in the cycle 2 and data packet n+2 at the end of the group with the current number 9 in the cycle 2. Likewise, from this there result waiting times of Atn, Atn+1 and Atn+2 respectively which, however, are considerably shorter when compared to the waiting times h: i REPLACEMENT SHEET 16- L- i- WO 92/00637 8 PCT/EP91/01202 according to Fig. 4e. This represents another advantage of the alternative according to Figs. 4f and 4g.

Using the installation on the receiver side illustrated schematically by means of Fig. 2, the broadcast RDS data stream is separated from the radio broadcast program signal in the RDS-compatible receiver and fed to an RDS decoder 21 which demodulates and decodes the carried RDS data stream.

The decoded RDS data stream is passed on to the stage 22 (which may also form part of the decoder 21) where the separation and evaluation of the "Variable Dynamics" control signal is carried out. When doing this, the information on the waiting time At contained in each data packet is also retrieved and this serves for controlling a subsequent buffer memory 23 for the "Variable Dynamics" control signal.

The control signal appearing at the output of the buffer memory 23 is once again synchronized with the associated signal segment of the program signal which is fed from the receiver 20 to a controlled amplifier 24. The control signal occuring simultaneously at the control input of the regulated amplifier 24 changes the amplification of the program signal according to a manual input 25 for the amplifier 24 so that the program signal reproduced via loudspeaker 26 or non-illustrated headphones respectively exhibits a dynamic corresponding to the individual wishes of the listener or the manual specification at input respectively. Hence, the execution of the procedure steps according to Figs. 4a through 4g are carried out on the receiver side in the reverse order to that of the transmitter side.

A further embodiment example on the receiver side, based on the idea that only a limited capacity is available in an RDS transmission channel for transmitting the "Variable Dynamics" control signal, is illustrated in Fig. 3.

Nevertheless, in order to guarantee, in particular, a data- REPLACEMENT SHEET ,z 1 Q1 WO 92/00637 9 PCT/EP91/01202 protected transmission in the RDS channel, typical control signal progressions (forms) are permanently stored in a memory 27 on the receiver side which is provided instead of the buff e memory 23 according to Fig. 2. Merely the addresses of the respective desired control signal progressions are transmitted as the contents of the data packets of the "Variable Dynamics" control signal, thereby taking up considerably less channel capacity than the transmission of the control signal progressions as such. In addition to the addresses of the permanently stored control signal progressions, the control signal values actually occuring on the boundaries of the program signal segments and used in the memory 27 for the plausibility check and/or correction and/or for initialization upon switching on the device, changing program or when the control signal is unavailable can be transmitted. The saving in capacity achieved with the help of this alternative technique is so large that each data packet can be transmitted twice in the RDS data stream, meaning a considerable increase in the transmissio, 7eliability.

A table with examples of typical control signal progressions is plotted below the circuit block 27 in Fig.

3; the following can be seen: a straight line with a gradient of 0 (constant dynamic) a straight line with a positive gradient (climbing dynamic) a straight line with a negative gradient (falling dynamic) signal leaps with various amplitudes, various directions and occuring at various times (jump-type dynamic I alterations according to size, direction and time).

OREPLACEMENT SHEET

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Claims (8)

1. A process for transmitting a time-variable control parameter which is derived from an associated radio broadcast program signal and is broadcast together with the program signal in order to be used, by a receiver, for the selection of a reproduction dynamic which can deviate from a transmitted program signal dynamic by being individually adapted during reproduction by the receiver to suit the wishes of the listener, in which the control parameter is a digital auxiliary signal which is inserted as data packets at intervals into a data stream which is transmitted in a program signal-free region of a transmission band of the radio broadcast program signal and the data packets being non-synchronized with the program signal wherein each control parameter is related to a segment of the program signal and that the insertion .e of the digital auxiliary signal is carried out with a n varying advance with respect to the related program sial segment and that a measure for the related variable oroo 4 20 advance is transmitted as a separate time information in each data packet and used, by the receiver, for synchronizing the control parameter with the program o segment.

2. The process according to claim 1, wherein a 25 multiplicity of typical control parameter progressions are permanently stored on the receiver side, and that the o*oe addresses of the permanently stored control parameter "":°progressions are transmitted as control parameters.

3. The process acCording to claim 2, wherein at least some of the control parameters occur on boundaries of two respective program signal segments and these control parameters are used by the receiver for a plausibility check and/or correction and/or for initialization upon switching on the device, changing program or when tne control parameter is unavailable.

4. The process according to any one of claims 1 to 3, Z) u 11 wherein the digital auxiliary signal is inserted into a data stream of a Radio Data Signal (RDS signal) which is transmitted on a auxiliary carrier in the multiplex channel of an FM radio broadcast program signal.

5. The process according to claim 4, wherein periodically repeated groups comprising sequences of data bits are provided in the RDS data stream for the transmission of the control parameter, and that a larger number of groups is provided in the RDS data stream than is necessary, and that only such groups are broadcast as are occupied with a data packet of the digital auxiliary signal.

6. The process according to claim 4, wherein the sequences of data bits are inserted into the RDS data stream between other groups each of which carries one data *o o °packet of the digital auxiliary signal as required.

7. The process according to any one of claims 1 to 6, ;o wherein the digital auxiliary signal is separated from the data stream and evaluated by the receiver. 'e 20

8. The process according to claim 7, wherein the measure for the related variable advance is retrieved upon evaluation uaid serves for controlling a memory which stores the current control parameter. DATED this 1st day of June 1994 0I TELEFUNKEN FERNSEH UND RUNDFUNK GmbH Patent Attorneys for the Applicant: F.B. RICE CO. AI *1e. K