DE2553632B2 - Process for converting analog signals into digital signals and from digital signals into analog signals - Google Patents

Description

ten codes the time slots of the associated subscriber station for recording signals and if necessary, the time slot sequence allocated for a delivery of signals in each case the desired one Can cause control of the counter of the analog-to-digital converter.

The invention is explained below with the aid of a drawing for example explained in more detail.

The circuit arrangement shown in the drawing is, as far as i '. £ n structure of the analog-digital converter and the associated subscriber station Tn is concerned, already in the patent application. P 25 38 543.7 described, which is why the structure of these circuit parts will not be discussed in detail here.

The circuit arrangement shown in the drawing differs from the circuit arrangement described in patent application P 25 38 543.7 essentially only in that the pulse recovery circuit 7s is not connected to the input side of the line y, PCMan leading to digital signals to be converted into analog signals is connected, but with its input / is connected to a separate control line Li. On this control line Ls , in the time slots of the time slot sequence assigned to the subscriber station Tn for receiving signals and, if necessary, for outputting signals, control pulses occur. From these control pulses, the pulse generation circuit Ts derives a control signal from its output 01 to the set input S of the bistable flip-flop KS , which is connected to the actuation input of the switch 51 with its output carrying a "1" output signal in the set state, Via which the counter Ct of the analog-digital converter is connected with its input e to the output of the clock generator Cl . The mentioned control signal can have a duration corresponding to the duration of a time factor.

At its output 02, the pulse generation circuit Ts emits clock pulses in a number corresponding to the number of bits belonging to a digital signal. These clock pulses are used to control the register stages of the input register Reg 1 and the output register Reg2, which is connected on the output side to the line PCMab.

By transferring the time slots of the subscriber station Tn for Aufnahr ■ · .: signals and possibly for the delivery of Sign: ia allotted time subject sequence corresponding pulses via the separate control line Ls can on the line PCMan to be transposed into analog signals to digital signals appear in some code.

1 sheet of drawings

Claims (1)

1
Claim: Method for converting analog sigmils, in particular PAM signals, into digital signals, in particular PCM signals, and for converting digital signals, in particular PCM signals, into analog signals, in particular PAM signals, in telecommunications systems with subscriber stations , which each have a transmitting device emitting analog signals and a receiving device receiving analog signals, which can also be connected to signal recording devices that receive digital signals or signal output devices that emit digital signals during the duration of time slots of time slot sequences with time slots that occur cyclically repeatedly in pulse frames are and each of which is associated with an analog-to-digital converter controlled by a counter for converting the analog signals into digital signals, whose Schailuftgsieil serving for the output of the analog signal corresponding to the analog signal to be converted for receiving an in to convert an analog signal Digital signal is used, the time slots of one of the subscriber stations being used for receiving signals and, if necessary, time slot sequence allocated for outputting signals for such control of the counter of the analog-digital converter that this counter is responsive to the occurrence of each such time slot out only executes one counting cycle, within which it runs through all "counters, make patent application. P 2.5 38 543.7, characterized in that in the time slots used for the said control of the counter (Ct) control pulses are transmitted via a separate control line (PCMan) that is separate from the transmission line (PCMan) used to transmit digital signals to the analog-to-digital converter (Ls) are supplied. The patent application P 25 38 543.7 relates to a method for converting analog signals, in particular PAM signals, into digital signals, in particular PCM signals, and for converting digital signals, in particular PCM signals, in analog signals, in particular PAM signals, in telecommunications systems with subscriber stations, the transmitting device emitting one analog signals and one analog signals have receiving receiving device, which further each during the duration of time fans of Time slot sequences with time slots with digital signals that occur repeatedly in pulse frames Signal recording devices or signal output devices which emit digital signals can be connected and each of which has an analog-to-digital converter for converting the analog signals into digital signals is associated, its for the delivery of the corresponding to the analog signal to be converted Circuit part used for digital signals for receiving a digital signal to be converted into an analog signal is exploited. When using a subscriber station-specific operating according to the iterative principle Analog-to-digital converter - with a counter, one through its counter signals controllable intermediate register, a digital-to-analog converter connected downstream of this intermediate register and a comparator connected to an input at the output of this digital-to-analog converter, which is supplied with the analog signals to be converted into digital signals at another input and the output of the counter signals to said intermediate register with its output signal able to control - during a one ίο Pulse frame corresponding duration within a Part of the time span the analog signal to be fed to the receiving device of the relevant subscriber station to be converted digital signal after storage in the named intermediate register in the associated digital-to-analog converter and within a different part-time period that of the associated Transmitting device of the subscriber station concerned emitted analog signal to be converted into a digital signal implemented in the associated analog-to-digital converter. The time slots of one of the participant sites for a time slot sequence assigned to a recording is used for such control of the counter of the analog-to-digital converter takes advantage of the fact that this counter only has one time on the occurrence of each such time slot Executes counting cycle, within which it runs through all counter settings. For the purpose of jointly using the time slots of one of the relevant subscriber stations for the admission of signals and possibly for the delivery of JO signals allocated time slot sequence is preferably a in the above-mentioned method Pulse extraction circuit used to convert each into an analog signal during the Duration of a time slot of the time slot sequence assigned to the named subscriber station Digital signal derives a control signal which is used for the aforementioned counter control. the Deriving such a control signal can, however, cause difficulties in certain cases especially if the bits ά.τ in analog signals The digital signals to be converted occur in unipolar NRZ code and at the beginning of a digital signal occurring bits are formed by "zero" bits. To remedy such difficulties, one could go for Ai the transmission of the digital signals to be converted into analog signals use a bipolar RZ code. However, the use of such a data center code sometimes encounters difficulties, in particular for energy reasons. The invention is accordingly based on the object of showing a way of how independent of the choice of the code for the digital signals to be converted into analog signals, the above-mentioned control of the Counter of the analog-digital converter can be made. The above-mentioned object is achieved in a method according to patent application. P 25 38 543.7 according to the invention in that in the time slots used for said control of the counter Control pulses via a separate one from the one used to transmit digital signals to the analog-to-digital converter towards serving transmission line are fed to a separate control line. Through this there is the advantage that by accepting the the provision of the transmission line mentioned is independent of the circuitry complexity the type of digital signals to be converted into analog signals