FR2581225A1 - METHOD FOR DETECTING A STARTING PULSE EMITTED BY A CENTRALIZED REMOTE TRANSMITTER AND A CENTRALIZED REMOTE RECEIVER FOR IMPLEMENTING THE METHOD - Google Patents

Abstract

THE INVENTION RELATES TO DETECTION OF A STARTING PULSE EMITTED BY A CENTRALIZED REMOTE CONTROL TRANSMITTER. THE PROPOSED PROCESS FOR THIS PURPOSE IS CHARACTERIZED IN THAT FOR THE DETECTION OF THE START PULSE S, THE BASIC BAND SIGNAL RETURNED IS TRANSITIONALLY STORED AND THIS STORED SIGNAL IS VERIFIED AS TO ITS LENGTH AND OR DENSITY OVER A PREDETERMINED LENGTH AND IS MULTIPLIED BY A DIGITAL REFERENCE SIGNAL R HAVING THE SAME LENGTH AND SHAPE OF A RECEPTION SIGNAL HAVING SUBJECTED NORMAL DISTORTIONS, AND IN THAT RECEIVER SYNCHRONIZATION IS ACCOMPLISHED WHEN THE CORRELATION VALUE OBTAINED BY THE MULTIPLICATION OF THE TWO SIGNALS A REACHES ITS MAXIMUM VALUE AND DOES NOT CONTINUE TO INCREASE. THE INVENTION CAN BE USED FOR CENTRALIZED REMOTE CONTROL RECEIVERS.

Description

Centralized remote control receivers are so-called receivers

  asynchronous, which, in the state of rest, when the transmitter does not emit, are not synchronized with it. This means that the receiver must be synchronized with the transmitter at the beginning of each broadcast. The centralized remote control command issued by the transmitter is also called centralized remote telegram

  and synchronization is performed for all telegrams

  centralized remote controls known using a

  so-called start-up impulse waiting for it to be

  being in the state of rest. As soon as the receiver has detected as such the start pulse, a pattern or pattern of pulses corresponding to the pulse pattern

  of the transmitter begins to unfold in this receiver.

  The latter is now synchronized with the transmitter.

  To maintain this synchronism, the transmitter and the receiver use the same time base, that is to say

the frequency of the network.

  The present invention relates to a method for detecting a start pulse emitted by an omnidirectional or centralized remote control transmitter, in a centralized remote control receiver and for synchronizing the receiver with the transmitter, wherein the reception signal is demodulated. , then digitized and the digitized signal is scanned or sampled and thus the baseband signal is restored or retrieved and

is subsequently exploited.

  Known methods of this type are for example de-

  written in the article "Integrierte elektronische Rundsteuer-

  empfânger ", ESV Bulletin, NI 10-1976.

  for example each signal transmitted to the operating part

  the centralized remote control receiver, as long as the pattern or pulse pattern does not yet run, can be considered as a start-up impulse and after

  its reception the flow of the impulse pattern, that is,

  say synchronization, can be started. This method, however, has the greatest probability of a startup error. As a refinement, it has been proposed to stop the impotence motive immediately when it can be supposed according to the appearance of the following signal, that there

  not a valid start pulse.

  It is obvious that the safe detection of the starting pulse and the "secure" synchronization which follows from it,

  of the receiver is a very important necessity.

  for the error-free operation of a centralized remote control receiver, which must be ensured in all circumstances but which in practice is considerably challenged by disturbances

who always manifest themselves.

  The object of the invention is to propose a method of the above-mentioned type, which allows a synchronization of the receiver which takes maximum account of

  transmission distortions and disturbances.

  This object is achieved according to the present invention in that for the detection of the start pulse, the recovered baseband signal is stored or transiently stored and this stored signal is checked as to its length and / or density on a predetermined length and is multiplied by a digital reference signal of the same length and shape of the signal which has undergone normal distortion, and that the synchronization of the receiver is accomplished when the correlation value obtained by the multiplication of the two signals has reached its maximum value and no longer increases. Practical experimentation of the method according to the invention has demonstrated that, on the one hand, the use of a reference signal having the form of the reception signal having undergone a normal distortion causes a centering of the start pulse in the reference signal and that the correlation value reaches its maximum just at the moment when the start pulse is in the center of the reference signal, and that, on the other hand, the method according to the invention, by the proposed verification of the stored signal and the correlation is virtually immune to disruptive impulses

  arriving earlier as against interstices or interstices

  disturbance valleys inside the start impulse. The invention also relates to a centralized remote control receiver for implementing the aforementioned method, with an input part and an operating part. The centralized remote control receiver according to

  the invention is characterized in that the part of operation

  tation includes a shift register for memorizing

  transient transmission of the restored baseband signal, with at least a number of places corresponding to the full length of a start pulse, and that a correlator is provided for the correlation of the content of the

  shift register with the reference signal.

  The invention will be better understood, and other purposes, features, details and advantages thereof

  will become clearer during the description

  explanatory text which will follow with reference to the accompanying schematic drawings given solely by way of example illustrating an embodiment of the invention and in which: FIG. 1 shows a simplified diagram of an electronic centralized remote control receiver,

  comprising a control member capable of being

  controlled; FIG. 2 shows a detail of a centralized remote control receiver according to FIG. 1, and FIGS. 3 to 6 are diagrams for

the explanation of the operation.

  The centralized remote control receiver

  1, is connected by its input terminals 1 and 2

  two conductors 3 or 4 of an alternating current network

  5, which are superimposed, in a manner known per se, remote control commands in the form of alternating current pulse sequences. For the power supply of the centralized remote control receiver, there is provided a power supply portion 6 which comprises a series connection connected to the input terminals 1 and 2 and having a protection impedance 7, a capacitor in series. 8 and a full-wave rectifier 9. A filter capacitor 10 and a Zener diode There are

  connected to DC terminals of the latter.

  From a mounting point between impedance

  7 and the series capacitor 8, a conductive

  12 extends on the one hand to a frequency selective receiving part 13 and, on the other hand, to a RC type member 14. The receiving part 13, which comprises, for example, RC type active filters such as selection means for the remote control frequency, is connected, on the one hand, to a negative collector rail 15 and, on the other hand, to a positive collector rail 16 and thus receives

  the power supply portion 6, the power supply voltage

  necessary. An output terminal 17 of the receiver part 15 is connected to a first input 18 of the

  operating part 19 of the remote control receiver.

  At a second input 20 of the operating part 19 is connected a conductor which leaves from a mounting point between the resistor and the capacitor of the RC-type member 14. Via the RC member 14, it transmits at the second input 20 of the operating part 19 a signal having the frequency of the grating, by means of which, in the operating part 19, a series or a sequence of clock pulses related to the frequency of the network is formed for an electronic time base for

  the exploitation of the received pulse sequences.

  The operating part 19, which is connected to the negative and positive collector rails 15 or 16 and which receives

  of the power supply portion 6 the power supply voltage

  necessary, is carried out in the form of a micro-

  a controller with a fixed programming chip and preferably according to a programming of masks. Since electronic operating parts for centralized remote control receiver are known, it is not necessary to give here other details. It is enough

  draw attention to the fact that the part of

  19 includes, inter alia, electronic memories and shift registers for storage or

  temporary or transitory storage of sequences of im-

  pulses received. Each of these stored pulse sequences is compared to a pulse sequence

  (remote control command) associated with the tele-

  corresponding command and, when a positive result of the comparison, is produced at a first or a second output 21 or 22 of the operating part 19 a signal of agreement or validation as an actuating signal of an organ A switch 23 'is associated, in the drawing, with the switching member 23 and, depending on whether the enable signal appears at the output 21 or 22, the switch 23' is put into operation. or out of service, which results in the connection of a current consumer 24 to the network 5 or the

disconnect from it.

  For actuation of the switch 23 ', a transistor

  A switching transistor 25 or a switching transistor 26 is made conductive by the signal appearing at the output 21 or 22 of the operating part 19, so that one or the other of the two windings 27 or 28 of a relay 29 becomes current conducting and switches on or off the switch 23 '. Protection diodes are connected in parallel with the windings 27 and 28 to protect the transistors 25 and 26 against inductive voltage peaks or peaks. Switching member 23 is associated with an accumulator or switching energy storage member 30, in the form of a capacitor

  accumulator with sufficient capacity for operation

of the switch 23 '.

  The centralized remote control receiver is

  shown in Figure 1, in a very simplified way. For a

  representation and more detailed description, one attracts

  attention to CH-PS 567 824 and Swiss Patent Application No. 714/85 and the article "Intergrierte electronische Rundsteuerempfänger" by H. de Vries in Bulletin SEV, No. 10/1976. As is apparent from this article, the frequency selection receiver portion 13 comprises a rectifier as an amplitude demodulator and a level detector mounted downstream thereof. The latter provides a digital signal, which is the baseband signal

  recovered or restored and distorted during transmission.

  The digitized signal is scanned or sampled and applied to the operating part 19. In the case of the present remote control receiver, it is recommended to use a multi-level level detector (A / D converter) which can be scanned digitally. several values the received signal demodulated. But, a simple two-digit scanning

can be imagined.

  The transmission of a remote control command begins, as is known, by the transmission of a first signal which is called the start pulse which ensures the synchronism between the transmitter and the receiver. Next, it follows the series of pulses which characterizes the order, which in a known system, in the system named "DECABIT" of the applicant of the present patent application, is

  composed of 5 other impulses and 5 interstices of im-

  urges. Each of these steps, like the startup impulse,

has a length of 600 ms.

  For the correct functioning of the remote control receiver, the detection of the start pulse is of vital importance because it is only after recognizing as such the start pulse and after

  that the time base has started, that

  in the operating part 19 of the received pulse sequence, that is, its comparison with the setpoint pulse sequence associated with the corresponding remote control receiver can be accomplished. The receiver waits in the state of rest the impulse

  starting. As soon as it has been detected, the receiver

  The transmitter is synchronized with the transmitter and a pattern or pattern of impulses begins to unfold in the

  receiver, which coincides with the impulse pattern of the transmitter.

  The operating part 19 comprises, according to FIG. 2, a shift register 31 and a register 32 that has the same number of bits that the scanning requires locations, so that a start pulse

  explored can find its place in all its length.

  The scanned signal explored is introduced into the shift register 31. In the register 32, a reference signal is stored. The different register locations 1 to n of the two registers 31 and 32 are connected to each other via digital multipliers 33 whose outputs of which connected to an organ

adder 34.

  FIG. 3 shows the registers 31 and 32 in a somewhat different representation: the line a represents the four-valued shift register 31 with n locations, in which a reception pulse S (start pulse) is in the process of being introduced from the right side; line b shows register 32 also at four values, in which a reference signal R with four values and n locations

is stored.

  The digital multipliers 33 and the adder member 34 (Fig. 2) now correlate the S and R signals so that. the output of the adder member 34 the correlation value K of the two signals S and R n K = Ä (R₁SS) i = 1 1 1 can be obtained. The maximum correlation value K is obtained during a maximum coincidence of the two signals S and R. The operating part 19 now checks in each operating or sampling interval, that is to say at the rhythm of the network, the contents of the shift register 31 and undertakes for this purpose the following verification: measuring the length of the signal S from the rising edge to the falling edge, by counting. This measure is hereinafter referred to as verification of

the length.

  counting the number of register places with a significant value greater than 0 (or greater than any level value). This count is designated

  in the following as density check.

  In addition, the content of the shift register 31 is multiplied by the digital reference signal R stored in the register 32 and thus the correlation value K of the two signals S and R is determined. In FIG. 4, reference is again made to FIG. to the reference signal R shown in line b of Figure 3: line a of Figure 4 shows the rectangular start pulse, which has been emitted; FIG. b shows the signal at the output of the demodulator on the

  receiver, the US threshold of the level detector being

  indicated; and line c represents the two-valued digitized reception signal S and shortcuts flanked by distortions and whose shortening is caused by the transient processes of the narrow-band filters in the transmitter and the receiver. In line d is shown a particularly suitable reference signal R, which has been chosen to correspond as closely as possible to the shape of the curve of a baseband signal (line b) received with normal transmission distortions. and which presents inclinations

to the front and back flanks.

  The examination of length and density, which comes

  to be described, of the reception signal as well as its correlation

  lation with the reference signal now provide optimal criteria for the detection of the pulse of

  start-up and synchronization of the tele-

  command: A pulse is accepted as a start pulse when it reaches a minimum length and does not exceed a maximum length (length check), or where, in the case of brief interfering gaps which, however, must not exceed

  example 2 binary digits - reaches a minimum density

  male and does not exceed a maximum density. The satisfaction

  faction of one of these two conditions constitutes the

  start-up criterion which must be satisfied for several

  several clock cycles. The synchronization, that is to say the start of an internal pulse memory is however only done when the correlation value is maximum, that is to say when it no longer continues to increase . In FIGS. 5 and 6, a diagram shows the synchronization method which has just been described, by means of the start criterion and the synchronization criterion. The left column shows in the first line the reference signal R stored in the register 32 (Figure 2) and which is formed according to the representation by the sequence "23333321". Below this is indicated the shift register 31 which comprises 8 memory spaces and into which the reception signal S "11111111" is fed from the right side. Below the shift register there is finally symbolized at each line respectively for the corresponding cycle the continuous introduction of the reception signal S in the shift register 31. The intermediate column shows if and when the start criterion is filled - " 0 "meaning not filled and" STARTING "meaning filled - and in the

  column on the right are introduced the correlation values

  corresponding K. The satisfaction of the synchronization criterion and thus the start of the pulse pattern

  internal is marked by an arrow.

  The starting criterion is determined by a density check, that is to say this criterion is satisfied when the reception signal S has a sufficient density of 6 to 8 binary digits, according to the

  representation, in the correlation window.

  FIG. 5 shows the method using a reception signal S having the nominal length of an 8-digit start pulse, while FIG. 6 illustrates the method with a disturbing pulse ST arriving too early, which is followed by

  reception signal S of 8 binary digits.

  As can be seen from FIG. 5, the starting criterion is satisfied from the 7th to the 11th cycle, the reception signal thus being recognized as a starting pulse in the 7th cycle. The correlation value K increases

  On a continuous basis, in the ninth cycle, it reaches its maximum value.

  male and then decreases. The timing criterion is fulfilled exactly when the start pulse is centered in the correlation window, or in others

  in the shift register 31.

  In the example of FIG. 6, as in FIG. 5 in the first cycle, the reception signal S is immediately in front of the shift register 31 in which, however, the disturbing pulse ST is introduced.

  comprising three binary digits. The disturbing impulse

  However, ST can not meet the start criteria since it can not meet the density test or verification. The same case as in FIG. 5 is obtained, that the starting criterion is satisfied from the 7th to the 11th cycle and the synchronization criterion is fulfilled at the 9th cycle, that is to say exactly when the start pulse S is centered in the window

correlation.

  If the gap between the disturbing pulse ST

  and the start pulse S was shorter than 3 digits

  However, this does not occur very often in practice, this would not have an embarrassing impact. In this case, the start criterion would be satisfied earlier, which would not be true for the synchronization criterion, however, since for the latter the correlation value K must no longer continue to increase, the pulse pattern internal would only be initiated in this case when the reception signal S is centered in the correlation window. It should also be mentioned that in FIG. 6 after the 3rd and 4th cycles, the correlation value K does not increase; but since at these cycles the start criterion is not satisfied, that is to say the reception signal S is not recognized as being a start pulse, the

  timing criterion can not be satisfied.

  Also in the case of a reception signal S reduced by no more than 2 binary digits, the synchronization criterion is always filled only when the reception signal is centered in the correlation window When, as has been described, the register 31 has a number of places such that a start pulse can find its place in all its length, it does not check during the verification of length and density if a pulse exceeds a maximum length or density, but only if it reaches the minimum length or density. For verification of exceeding the maximum length or density, which is reasonable when the remote control telegram has a gap after the start pulse, the shift register 31 must include a number of places exceeding the length of a pulse

starting.

  The disclosed method provides maximum security for the detection of a start pulse and for the correct timing of the centralized remote control receiver. This is obtained, on the one hand, by the adaptation carried out by means of the inclinations to the front and rear flanks, of the reference signal in the form of a normally distorted reception signal, and on the other hand, by the definition of a start criterion (length and density check) and the synchronization criterion.

258 1,225

Claims (9)

R E V E N D I C A TI 0 N S   A method for detecting a start pulse emitted by a centralized or omnidirectional remote control transmitter, in a centralized remote control receiver and for synchronizing the receiver with the transmitter, wherein the reception signal is demodulated, and then digitized and the digitized signal is explored or sampled, the baseband signal thus restored or recovered is then used, characterized in that for the detection of the start pulse (S), the restored baseband signal is stored transiently and this stored signal is checked for its length and / or density over a predetermined length and is multiplied by a digital reference signal (R) having the same length and shape of a reception signal having   suffered from normal distortions, and that synchronization   receiver is accomplished when the correlation value obtained by multiplying the two signals has   reaches its maximum value and does not continue to increase.   2. A method according to claim 1, characterized in that the restored baseband signal is introduced into a shift register (31) which comprises a number (n) of places corresponding to the entire length of a start pulse (S), and in that the contents of the shift register are checked in each scanning or sampling interval over the length of a start pulse as well as on the number of register places whose significant value does not exceed not   a predetermined threshold value.   3. Process according to claim 2, characterized   in that the signal (S) stored in the deceleration register   lage (31) is recognized as a start-up pulse when a) its length has reached a minimum value and does not exceed a maximum value, or b) when there are brief gaps in the signal under examination, it occupies a number of register places with a signi fi cant value not exceeding the predetermined threshold value, said number reaching   a minimum value and not exceeding a maximum value.   4. A method according to claim 3, characterized in that the synchronization is done only when the correlation value reaches its maximum at the instant at which simultaneously a start pulse is detected.   5. Method according to one of claims 1 to 4,   characterized in that the reference signal (R) and the   shift register (31) have a significant value   corresponding to the digitization of the demodulated reception signal. 6.Procédé according to claim 5, characterized in that the reference signal (R) comprises at its front and rear flanks inclinations adapted to the   form of the normally distorted reception signal.   7. Centralized remote control receiver for carrying out the method according to claim 1, with an input part and an operating part, characterized in that the operating part (19) comprises a shift register ( 31) for transient storage of the restored baseband signal, with a number of places corresponding to at least the total length of a start pulse, and that a correlator is provided for the correlation of the contents of the   shift register with the reference signal (R).   8. A centralized remote control receiver according to claim 7, characterized in that the operating part (19) comprises a register (32) in which the reference signal (R) is stored, and in that the reference signal and the shift register (31) comprise a significant value corresponding to the   digitizing the demodulated reception signal.   9. A centralized remote control receiver according to claim 8, characterized in that the shift register (31) and the register (32) comprise the same number (n) of register spaces, and in that register places which correspond of the two registers are connected by numerical multipliers (33), whose outputs are connected to an adder member   (34) for forming the correlation value.