DE3603826A1 - Arrangement for transmitting voice signals - Google Patents

Abstract

Circuit arrangement for transmitting voice signals in a line-connected communication system with multiple access and decentralised switching. It is the object of the invention to create a circuit arrangement for implementing a digital local-area communication system for low numbers of subscribers with little traffic load, which operates in accordance with the code division multiplex principle. The object is achieved by the fact that the access station of the access level which is connected to the network switching unit of the network level and the terminal of the terminal connection level consists of a code division multiplexer, a code division demultiplexer, an operating unit and a controller. According to Figure 3, the operating unit consists of a call key, a stop key, a directory-number register, a ringing signal output, a keyboard and a display unit; the code division multiplexer consists of an AND gate, a parallel/serial converter, an address memory, a ringing generator and a change-over switch; the code division demultiplexer consists of a call detector, a delay line, a switch network, an adder and a sampling circuit. Connecting the said elements of the arrangement provides for subscriber-synchronous and bit-synchronous operating modes. The invention is particularly suitable for use in local area networks. <IMAGE>

Description

Arrangement for the transmission of speech signals

The invention relates to an arrangement for the transmission of speech signals in a wired messaging system with multiple access and central Mediation that works on the odemultiplex principle and is particularly suitable for use in local networks.

An arrangement for messaging with multiple access has already been established and decentralized switching according to WP H 04 i ,, / 266 109.3 proposed in the the communication network is connected to one another via defined interfaces There are independent levels, with the terminal connection level having different modules includes, which are provided for connecting different terminals, the access level consists of access stations, on the one hand with several modules of the terminal connection level and, on the other hand, the exchange of information via network couplers at the network level with the sending line and receiving line ensured, and being the network level as a hybrid line network, consisting of copper cables and fiber optic cables and passive ones and active network couplers.

A high sensitivity is only possible here through a high degree of synchronization achievable, which in turn can only be implemented with great effort. In the realization of communication networks with low numbers of participants and little traffic, which are primarily intended for voice signal transmission, there is the disadvantage the arrangement according to the time division multiplex principle in the high circuit wall, the caused in particular by the high level of synchronicity required.

The aim and object of the invention is to provide a against disturbances in highly insensitive and low-circuit arrangement exhibiting for the implementation of a digital local message system for small numbers of participants to create with low traffic offer, which according to the code division multiplex principle works and is used for the switching and transmission of preferably voice signals and in which the access stations of the communication system for signal transmission Bit synchronism and subscriber synchronism to establish a connection demand.

According to the invention the object is achieved in that each access station from a code multiplexer, a controller, an Oodeeinultiplexer and an operating unit consists. The control unit is with the control, the code multiplexer and the code demultipreader connected and the control is still in connection with the code multiplexer, the source coder, the source decoder lld the regenerator of the transmission line.

Furthermore, the odemultiplexer with the source encoder and the Regenerator of the transmission line as well as the code demultipreader nit the regenerator of the Receive line and the source encoder interconnected.

The control unit consists of a call button, a stop button, a call number register, a callsign output, a keyboard and a display unit. There are those Call button and the stop button with the control and the call recognition of the code multiplexer connected to the telephone number register and the callsign output.

The code multiplexer consists of an AND element, a parallel-to-serial converter, an address memory, a RXufgenerator and a switch. The lower part is with the parallel-serial converter, the switch and the regenerator of the transmission line and the parallel-serial converter, the address memory, the call generator and the switch are connected to the controller. Furthermore, the call generator with the switch, the address memory with the parallel-serial converter and the switch with the source-coded interconnected.

The code multiplexer consists of a call detection, a delay line, a switch network, a summer and a sampling circuit 0 Here are Call recognition with the generator of the receive line, the delay line, connected to the summer, the sampling circuit and the source decoder. The delay line is connected to the switch network and the regenerator of the receiving line.

There are also connections between the switch network and the summer, between the summer and the sampling circuit and the source decoder0 Under the prerequisite that the access identification is only possible with the regenerator of the receiving line, with the delay line, the summer, the sampling circuit, the source decoder and the callsign output is interconnected and that the source encoder is off a delta modulator and the source decoder consist of a delta modulator, an asynchronous circuit arrangement is implemented.

The switch network in the code demultiplexer can be omitted here if according to the code word combination, only the outputs of the Delay line with a corresponding number of inputs of the summer are directly connected.

Another possibility is that to the outputs of the delay line a number of switches corresponding to the length of the code word are switched on, which are connected to the inputs of the adder and that only those for Decoding of the code word required outputs of the delay line switched through and the remaining switches are open.

In principle, a connection is established by using the digitally coded Source signals are multiplied by the code word of the receiver. The Access station, the four operating states call, readiness to receive calls, call Adopt detection and bidirectional exchange of information.

When establishing a connection from station A to another station B First subscriber A keys in the number B.

The selected number B will appear on its display. Then will the ilu key pressed This sends a header block.

This head block consists of two parts. The first part serves the Synchronization of the receiver B and contains a certain number of synchronization symbols.

The second part contains the SCV-coded address of subscriber A.

If station B is ready to receive at this point in time, d. i.e., station B is not in dialogue with any other station and is trying do not establish a connection, your receiver synchronizes with the first part of the header and reads in the address part. On the display the Station B appears the number A and there is a callsign over the callsign output triggered. Subscriber B in turn confirms the call button and the synchronization process Sender B to receiver A starts up. From this moment on the connection is established, and subscribers A and B can exchange information in duplex mode. the Connection is broken off by pressing the stop button.

The invention is explained below using an exemplary embodiment will.

In the accompanying drawings, Sig. 1 shows line network dough. 2 principal Structure of a subscriber station Sig. 3 assemblies of an access station 1 message systems with multiple access and decentralized switching mainly use line-saving Network structures, for example line and ring networks. Sig. 1 shows a network version in line form with connected participant stations after the. Code division multiplex work.

The subscriber stations T are over a common transmission line SL and receiving line EL connected to one another, with transmission line Sit at the end and receiving line are short-circuited.

Each subscriber station T consists of the network coupler 11K, the access station ZS and from the actual terminal EG.

The signals between the named Assemblies exchanged.

Code division multiplexing and multiple access take place digitally, with only binary signals are transmitted.

To implement a simple digital overlay of the signals, bit synchronism is assumed. Bit clock synchronization is therefore at the beginning the transmission line SL a clock generator TG is required.

In principle, a connection is established using the digitally coded Source signals of the source encoder QC multiplied by the code word of the receiver and transmitted. In order to be able to establish and maintain a connection, is subscriber synchronicity still required, d. H. synchronize two call partners their exchange of information with each other.

ig, 2 shows the basic assemblies of the terminal EG, the access station ZS and the network coupler NK.

The terminal EG consists of the actual voice source SQ and the Speech sink SS, as well as from the source coder QC and the source decoder QD. Of the Source encoder QO converts the analog speech signal into a digital source signal around and sends this on as a data signal DQC to the access station ZS, with he source coder QC from the control part ST of the access station ZS via the signal TQC is synchronized and clocked. In addition to a pulse code modulator, the source encoder QO also z. B. be implemented as a delta modulator0 accordingly. the source decoder QD, which receives its signal DQD from the access station ZS, through a pulse code demodulator or implemented by a delta modulator.

The source decoder is synchronized and clocked with the Signal TQD in front of the control ST of the access statics ZS.

The access station ZS consists of the code multiplexer function modules CMU, control ST, operating unit BE and code demultiplexer CDE.

The odemultiplexer OMU transfers the transmission signal to the subscriber station T the regenerator of the transmission line RSL, which, like the regenerator, of the reception line REL regenerates the incoming line signals, the access station ZS takes as data signal DSL, or as data signal DEL and clock signals TSL and TEL makes available and forwards it.

The bit clock synchronous continues to be used in the regenerator of the transmission line RSL Superimposition of the various transmission data signals implemented.

The signals from the control unit are also transmitted via the code multiplexer CMU BE, such as the signals for participant synchronism, are passed on, with the code multiple er lU is synchronized and controlled by the controller ST.

The odemultiplexer CDE receives via the regenerator of the receiving line REL all transmitted signals and transfers the recognized call signals to the control unit BE or data signals to the source decoder QD.

The implementation of an access station ZS is shown in FIG rig. 3. The control unit BE contains the call button S1, the stop button S2, the keyboard TA, the display unit AE, the telephone number register RR and the callsign output RZ.

The code multiplexer Otv consists of a parallel-to-radio converter PS, an address memory AS, a call generator RG, an AND element UG and a switch S3.

The code demultiplexer CDE contains the assemblies call identification RS, Delay line VL, switch network VR, summer SU and sampling circuit AB.

The access station ZS can assume four different operating states. In addition to the call, readiness to receive calls and call recognition, the exchange of information bidirectional or ii duplex operation can be implemented.

The mode of operation of the circuit arrangement is illustrated using the example of source coding and decoding by De lt amodulations method explained. Owns a participant A sends a request to another subscriber BS so he first scans his call number into the keyboard TA an The dialed number is BCD coded and in the telephone number register RR saved.

The address memory AS is thus addressed and at its outputs the first part of the code word, which is assigned to the called subscriber B, appears is. At the same time, the display unit AZ shows the number stored in the call number register RR Phone number.

After pressing the call button S1, the control delivers the corresponding Clocks to the address memory AS and the parallel-serial converter PS and switches the call generator RG on * The call generator EG first sends a sequence of synchronization symbols and then the BCD-coded phone number of subscriber A.

The call generator RG is then switched off by the controller ST and the delta modulator is switched on by switch S3.

The code words arriving from the parallel-to-serial converter PS are with the digital signals coming from the output of the delta modulator in the AND element UG AND-linked and get to the network coupler LK.

The ensures the correct phase position of information and code word Control circuit ST.

At the time of the call, subscriber B should be in the ready state are0 The entire multiplex signal on the receiving line EL passes through the Delay line VL and is checked bit for bit for coincidence. When In the event of errors, information bits are recognized incorrectly and the caller ID does not speak at. A call is only recognized when all synchronization symbols are in the system time grid arrive one after the other. The caller identification RE triggers via the call sign output RZ the call signal and forwards the following signal to the call number register LR. Through this the register of subscriber B is loaded with the number of subscriber A. These The number is displayed and the address memory AS is addressed accordingly.

This is the prerequisite for a conversation between participants A and B created. After the call has ended, the stop button S2 will press the Control ST blocked and the code demultiplexer CDE again in the ready state set.

Provided that the source encoder QC consists of a delta modulator and the source decoder QD consist of a delta modulator, the synchronism can the circuit arrangement is limited to bit-synchronous transmission and d or the participant synchronism is omitted. According to lig. 3 this happens by that on the connection of the caller identification RF of the code demultiplexer CDE to the call number register RR is waived.

The delay line VL in the code demultiplexer ODE can because of the digital signal transmission implemented very easily using a clocked sliding chain at whose parallel outputs only those to be expected according to the code word specification High-Q outputs are fed directly to the summer SU. The totalizer represents in simplest; each a NAND gate with a number corresponding to the high level of inputs. The totalizer only outputs if its own code word is recognized SU emits an impulse. If the code word z. B. 12 bit length with 5 Eigk symbols and 7 low symbols, a NAND gate with 5 inputs is required. Because in this considered lall the delay line VL and the summer SU connected directly there is no switch network VR.

The switch network ER so between the outputs of the delay network VL and the inputs of the adder SU can be switched by using a number of analog switches corresponding to the length of the code word are interposed0 This switch network is programmed in such a way that only the high level leading positions of the outputs of the delay line are switched through all other inputs of the summer SU are switched on by the U-m switch Fixed high reference potential clamped. In this case, SU becomes a for the summer NAND gate with a number of inputs corresponding to the code word length.

Claims (7)

Claims 1. Arrangement for the transmission of voice signals, consisting of a transmit line and a receive line at one end connected to each other and open at the other end and from a communication network, which is formed from three levels, so that the connection in the terminal connection level to a terminal with a language source that belongs to the access level Access station via defined interfaces on the one hand with a terminal of the Terminal device connection level and on the other hand via network couplers of the network level with the transmission line and is connected to the receiving line, and that the network coupler is the regeneration Realize the line signals of the transmission line and the receiving line, marked in that the access station (ZS) consists of a code division multiplexer (CMU), a code demultiplexer (CE), a control (ST) and an operating unit (BE), the operating unit (BE) with the controller (ST), with the code multiplexer (3IU) and with the code demultiplexer (CDE), the control (ST) with the code division multiplexer (CMU), with the source encoder (QC), with the source decoder (QD) and. with the regenerator of the transmission line (RSL), the code division multiplexer (CMU) with the source encoder (QC) and with the regenerator of the transmission line (RSL), and the code demultiplexer (CDE) with the regenerator of the receiving line (REL) and with connected to the source decoder (QD). 2. Arrangement according to claim 1, characterized in that the operating unit (BE) from a call button (S1), a stop button (S2), a call number register (RR), a call sign output (RZ), a keyboard (TA) and a display unit (AZ) consists, whereby the call button (S1) and the stop button (S2) with the control (ST), the call number register (XR) with an address memory (AS) of the code division multiplexer (CMU) and with a call recognition (RE) of the code demultiplexer (CDE) and the callsign output (RZ) is connected to the call detection (RE) of the code demultiplexer. 3. Arrangement according to claim 1 and 2, characterized in that the Oode multiplexer (MU) from an AND element (UG), a parallel-to-serial converter (PS), an address memory (AS), a call generator (RG) and a switch (S3), where the AND element (UG) with the parallel-series converter (PS), the switch (S3) and the regenerator of the transmission line (RSL), the Earallel series converter (PS), the Address memory (AS), the call generator (RG) and the switch (S3) with the control (ST), the call generator (RG) continues with the switch (S3), the address memory (AS) with the parallel-serial converter (ES), and the switch (53) with the source encoder (QC) is connected. 4. Arrangement according to claim 1 to 3, characterized in that the Code demultiplexer (CDE) from a caller identification (RE), a delay line (VL), a switch network (VR), a summer (SU) and a sampling circuit (AB) consists, the call detection (RE) with the regenerator of the receiving line (REL), the delay line (VL), the summer (SU), the sampling circuit (AB) and the source decoder (QD), the delay line (VL) with the regenerator of the receiving line (REL) and the switch network (VR), the switch network (VR) with the adder (SU), the adder (SU) with the sampling circuit (AB) and the sampling circuit is connected to the source decoder (QD). 5. Arrangement according to claim 1 to 4, characterized in that the Source encoder (QC) from a delta modulator and the source decoder (QD) a delta modulator and the caller identification (RE) of the code demultiplexer (CDE) only with the regenerator of the receive line (REL), the delay line (VL), the summer (SU), the sampling circuit (AB), the source decoder (QD) and the callsign output (RZ) is connected. 6. Arrangement according to claim 1 to 5, characterized in that. that according to the Oode value of the subscriber station (T) only the High-potential leading outputs of the delay line (VL) with a corresponding Number of inputs of the totalizer (SU) are directly connected. 7. Arrangement according to claim 1 to 6, characterized in that. that at the outputs of the delay line (XL) one of the code value length corresponding number of switches connected to the inputs of the totalizer (SU) and only those required to decode the code value Outputs of the delay line (VL) switched through and the other switches open are.