DE1270121B - Carrier frequency system for n speech channels - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

Number:
File number;
Registration date:
Display day:

H 04 j

German KL: 21 a2-39 / 10

P 12 70 121.2-31
February 28, 1959
June 12, 1968

The main patent 1 028 620 relates to a carrier frequency system for four speech paths with one Channel bandwidth of 4 kHz, which is used both for the transmission of individual message channels in two-wire operation used as well as operated as a multi-wire lay system or two-wire separated lay system can be. The carrier frequency system is a so-called pre-channel system with double frequency conversion built by the union of the following, some known per se Individual features is marked:

a) The upstream channels are in the same frequency position both in control sequence and in sweeping sequence built up,

b) the pre-channels are above the highest transmission level and are by means of the carrier frequencies 44 and 48 kHz implemented in the same frequency position;

c) the pre-channels are converted from this frequency position (44 _ao to 48 kHz) into the transmission position by means of the carrier frequencies 52, 56, 60 and 64 or 72, 76, 80 and 84 kHz;

d) to suppress the upper sidebands for the second modulation The transmission band composed of the four individual channels is used for each transmission direction only one common low-pass filter at the transmit end;

e) the channel band filter, which is uniform for both transmission layers, has one towards the center of the band symmetrical attenuation curve.

Carrier frequency system for η speech paths

Addendum to the patent: 1 028 620

Applicant:

TE KA DE Feiten & Guilleaume
Telecommunication systems G. mb H.,
8500 Nuremberg 2, Bierweg 170

Named as inventor:

Dipl.-Ing. Albert Fritz,

Dipl.-Ing. Helmut Sippel, 8500 Nuremberg

The present invention represents a development of this carrier frequency system for speech paths with a channel bandwidth of 4 kHz to a carrier frequency system for η speech paths and gives the teaching that the pre-channels are constructed by means of two pre-channel carriers differing from one another by the zero frequency distance between two channels and then by means of two groups of each η also differing by the zero frequency spacing of the individual channels and channel carriers lying above the pre-channel carriers are converted into two seamless transmission bands, which in turn have a frequency spacing of one channel width from one another.

For the transmission of individual communication channels in two-wire operation (EK) , the upstream channels with a frequency sequence are converted into the transmission position with the channel carriers with uneven ordinal numbers in each group and the vox channels with the other frequency sequence with the channel carriers with even ordinal numbers in each group.

For a four-wire synchronous operation (V 4), the upstream channels of only one frequency sequence with the channel carriers of only one of the two channel carrier groups are converted into the transmission layer.

For a two-wire separated layer system (Z 4), the transmission belt is connected to one of the two pre-channel carriers implemented in the transfer position of the second transfer belt (for the opposite direction). In the case of a two-wire separation system, those with a frequency sequence are also used Upstream channels each with the channel carriers of one group and those with the other frequency sequence Upstream channels each implemented with the channel carriers of the other group in the transmission layer.

With the teaching given with the invention, it is possible to build carrier frequency systems that have a should have a different number of speech paths from 4 and where applicable also the Bandwidth has been changed compared to 4 kHz in the main patent.

Claims (5)

Patent claims: 1. Further development of the carrier frequency system for four speech paths with a channel width of 4 kHz according to patent 1 028 620, in which the voice frequency bands in the first modulation stage in Upstream channels with the same frequency position, which are above the highest transmission position, and in a second modulation stage in side-by-side 809 559/354 The corresponding frequency positions are implemented to form a carrier frequency system for η speech paths, characterized in that the pre-channels are built up by means of two pre-channel carriers differing from one another by the zero frequency distance of two channels and then by means of two groups of η each also differing from one another by the zero frequency distance of the individual channels and above the channel carriers lying upstream are converted into two seamless transmission bands, which in turn have a frequency spacing of one channel width from one another. 2. Carrier frequency system for η speech paths according to claim 1, characterized in that the pre-channels having a frequency sequence each with the channel carriers with odd ordinal numbers of each group and the pre-channels having the other frequency sequence are implemented with the channel carriers with even ordinal numbers of each group in the transmission layer (EK). 3. Carrier frequency system for η speech paths according to claim 1, characterized in that the upstream channels are converted into only one frequency sequence with the channel carriers of only one of the two channel carrier groups in the transmission layer (V 4). 4. carrier frequency system for η speech paths according to claim 3, characterized in that the Transfer belt with one of the two pre-channel carriers in the transfer layer of the second Transfer belt (for the opposite direction) is implemented (Z 4). 5. Carrier frequency system for η speech paths according to claim 1, characterized in that the pre-channels having a frequency sequence are implemented with the channel carriers of one group and the pre-channels having the other frequency sequence are implemented in the transmission layer with the channel carriers of the other group (Z 4) . Considered publications:
German interpretative document No. 1 028 620. 809 559/354 5.68 © Bundesdruckerei Berlin