DE1052463B - Carrier frequency system for four speech channels - Google Patents

Description

The invention relates to a carrier frequency system for four speech paths with a channel bandwidth of 4 kHz, in which all channels are brought directly into the transmission position by direct conversion and which is used both for the transmission of individual calls in two-wire operation (EK) and as a multiple two-wire separate position. System (Z 4) or four-wire equalization system (V4) can be operated, with either two channels of one transmission direction and two channels of the other transmission direction (EK) or four channels of the same transmission direction (Z 4 or V 4) in two Frequency bands lying in the same frequency position are strung together without gaps, according to patent application F 21804 VIIIa / 21 a ² , 39/10.

The invention is based on the object of constructing such a carrier frequency system in such a way that switching from one operating mode to the other can be carried out with the least amount of switching elements. According to the invention, this object is achieved in that in each terminal there are two channel converters (KUl and KU2) of completely identical construction and designed as independent assemblies and in each of them two different, frequency-adjoining channel filters are arranged and that the four frequency-adjoining channel filters are two adjacent Channel converters are connected in parallel with one another on the output side.

Another feature of the invention is that when switching from single-channel operation (EK) the channel filters of the first two, connected in parallel on the output side, to four-wire equal-position operation (V4) Channel converter on the input side in successive frequency order with the transmitter modulators the four channel converters and the channel filters of the second two channel converters in the same Sequence with the reception modulators of the four channel converters and at the same time the transmission and receiving modulators of the channel converter of the carrier frequencies required for single-channel operation (8 and 16 kHz) to the carrier frequencies corresponding to the number of channels (8, 12, 16 and 20 kHz) be switched.

The invention is described in more detail below with reference to the drawings and explained. It shows

1 shows the frequency plan of the carrier frequency system when operated as a single channel system (EK),

Fig. 2 shows the frequency plan of the carrier frequency system when operated as a four-wire equilibrium system (V4) or two-wire separation system (Z4),

3 shows the block diagram of a carrier frequency system according to the invention.

Carrier frequency system for four speech paths

Addition to patent application F21804 VIIIa / 21 a ²
(Laying out guide 1 041 092)

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Applicant:
Feiten & Guilleaume
ο Fernmeldeanlagen GmbH,

Nuremberg, Äussere Bayreuther Strasse /
Bierweg 180

Dipl.-Ing. Helmut Sippel, Dipl.-Ing. Georg Märkl
and Dipl.-Ing. Dr. Konrad Scherer, Nuremberg,
have been named as inventors

From the frequency plan it can be seen that in single-channel operation (FIG. 1) the associated channels of two speech paths (i.e. channels 1, 1 'and 2, 2' or 3, 3 'and 4, 4') each form a gapless frequency band of 4 ... 20 kHz are combined. The individual voice channels of each speech path are in the one direction of transmission in the inverted position and in the other direction of transmission in the normal position. Each of the two seamless frequency bands can be transmitted in two-wire operation via one pair of wires each.

In the case of four-wire multiple operation (FIG. 2), on the other hand, the four channels are each of the same transmission device lined up with a frequency band of 4 ... 20 kHz each. In this case lie the individual voice channels in both directions of transmission upside down, and the transmission of the two frequency bands takes place separately for each transmission direction via a pair of wires.

If there is only one double line for the transmission of all four speech paths, i. H. only one pair of wires available, the system must be operated as a two-wire separation system (Z 4), - d. i.e., the frequency band of 4 ... 20 kHz must for one direction of transmission in a higher frequency position and be brought from the inverted position to the normal position at the same time. This happens in the application example shown by converting the direction of the same by means of the frequency 44 kHz using the lower sideband in the frequency range of 24 ... 40 kHz.

The four channel converters (Fig. 3) have a uniform structure and are designed as independent assemblies.

80 »769/388

Claims (3)

det, which each consist of a transmitter modulator vSlMl. .. vS "M4 and a receiving modulator EM 1 ... EMA as well as two channel filters for two frequency-wise adjoining transmission channels. Two of the four channel converters are completely identical, ie equipped with the same channel filters; they differ from each other in pairs in that the Channel filters of two channel converters of the same type adjoin the channel filters of the other two channel converters of the same type in terms of frequency, so that the channel filters of two different channel converters each encompass a seamless frequency band. In the exemplary embodiment shown, this frequency band is in the frequency range of 4 ... 20 kHz. The channel converters KU la and KUl b are the channel filters for the transmission channels in the frequency ranges of 4 ... 8 and 8 ... 12 kHz and the channel converters KU2a and KU2b are the channel filters for the transmission channels in the frequency ranges 12 ... 16 and 16 ... 20 The channel filters are assigned two each he adjacent channel converter with different ordinal numbers, d. H. that is, the channel converter 1 a and 2a or Ib and 2b are connected in parallel with each other on the output side and are each firmly connected to a line pair {KUla and KU2a with line a and KUlb and KU2b with line b). The channel filters are shown in the block diagram as transmission filters vS1jFl .. in accordance with the functions assigned to them in single-channel operation. SFA and receive filterEi7I ... EF 4 designated. Furthermore, a transmission modulator SM1 is in each channel converter. . . SMA and a receiving modulator EMI ... EMA arranged, which always have the same function in all three operating modes of the system. When switching the carrier frequency system from single-channel operation (EK) (shown in dashed lines in the block diagram) to four-wire equalization operation (V 4), only the channel filter EF1 with the modulator vS "M2, the Channel filter vS * P2 with the modulator SM 3, the channel filter EF2 with the modulator vSW 4, the channel filter SF 3 with the modulator EM 1, the channel filter EF 3 with the modulator EM 2 and the channel filter vS "F4 with the modulator EM 3 will. The channel filters EF1 and EF 2 of the channel converters 1 a and 2 a thus get the function of transmission filters and the channel filters SF3 and SFA of the channel converters 1 b and 2 b that of reception filters. In addition, when switching from single-channel operation to four-wire synchronous operation, the transmit and receive modulators of channel converter 2 a must be switched from 16 to 12 kHz, those of channel converter 1 b from 8 to 16 kHz and those of channel converter 2 b from 16 to 20 kHz will. Due to the structure of the carrier frequency system according to the invention, a total of only nine changeover contacts are required for switching from single-channel operation to four-wire synchronous operation; this is the minimum number of changeover contacts with which this changeover can be achieved. When switching from four-wire equal-position operation (V4) to two-wire Götaenntlaige operation (Z4), only one of the two transmission groups has to be switched to the frequency position 24 ... 40 using a directional converter kHz. Patent claims: 1. Carrier frequency system for four speech paths with a channel bandwidth of 4 kHz, in which all channels are brought directly into the transmission position through direct conversion and which is used both for the transmission of individual calls in two-wire operation (EK) and as a multiple two-wire separate position system ( Z 4) or four-wire equalization system (V4) can be operated, with either two channels of one transmission direction and two channels of the other transmission direction (EK) or four channels of the same transmission direction (Z4 or V4) in two in the same frequency position lying frequency bands are strung together without gaps, according to patent application F 21804 VIIIa / 21a2, 39/10, characterized in that in each terminal there are two completely identical channel converters (KU 1 and KU2) designed as independent assemblies and in each of them two different, Frequency-related channel filters (4 ... 8 and 8 ... 12 or 12 ... 16 and 16. .. 20 kHz) and that the four frequency-adjoining channel filters of two adjacent channel converters are connected in parallel with one another on the output side. 2. Carrier frequency system according to claim 1, characterized in that when switching from single-channel operation (EK) to four-wire synchronous operation (V4), the channel filters connected in parallel on the output side of the first two channel converters (KUla and KU2a) on the input side in successive frequency order in each case with the Transmit modulators (SMl ... SM A) of the four channel converters and the channel filters of the second two channel converters (KU 1 b and KU 2 b) connected in the same order to the receiving modulators (EMI... EM A) of the four channel converters and at the same time the Transmit and receive modulators of the channel converters can be switched from the carrier frequencies (8 and 16 kHz) required for single-channel operation to the carrier frequencies (8, 12, 16 and 20 kHz) corresponding to their number of channels. 3. Carrier frequency system according to claim 2, characterized in that when switching on two-wire separation operation (Z 4) one of the two transmission groups - in itself known Way - by means of an intermediate converter (44 kHz) with simultaneous reversal of the transmission position the voice channels are brought to a higher frequency position (24 ... 40 kHz). 1 sheet of drawings © 309'769 / 388 3.59