GB521340A - Improvements in and relating to electric communication systems - Google Patents
Improvements in and relating to electric communication systemsInfo
- Publication number
- GB521340A GB521340A GB2401538A GB2401538A GB521340A GB 521340 A GB521340 A GB 521340A GB 2401538 A GB2401538 A GB 2401538A GB 2401538 A GB2401538 A GB 2401538A GB 521340 A GB521340 A GB 521340A
- Authority
- GB
- United Kingdom
- Prior art keywords
- groups
- group
- frequency
- carrier
- carrier channels
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J1/00—Frequency-division multiplex systems
- H04J1/02—Details
- H04J1/12—Arrangements for reducing cross-talk between channels
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radio Relay Systems (AREA)
Abstract
521,340. Multiplex transmission. TELEPHONE MANUFACTURING CO., 'Ltd., and PADDLE, L. H. Aug. 15, 1938, No. 24015. [Class 40 (iv)] A multiplex system comprises a number of suppressed-carrier channels occupying the frequency spectrum up to 20KC. and a number of transmitted carrier channels which are divided into groups such that after the first (or only) modulation stage the highest frequency in the groups is less than twice the lowest carrier frequency in the group. As shown, the suppressed carrier channels are fed to line through amplifier GA1 and filter GF1. The transmitted carrier channels are grouped in fours and modulate carriers of 20, 24, 28 and 32 KC. respectively. Three bf these groups are then raised in frequency in further modulators GM1, GM2, GM3. The converse arrangement is used at the receiver. In a repeater arrangement Fig. 3 (not shown), the transmitted band is split into groups by filters so that in any group no harmonic of a carrier falls within the range of the group, each group being amplified separately.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2401538A GB521340A (en) | 1938-08-15 | 1938-08-15 | Improvements in and relating to electric communication systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2401538A GB521340A (en) | 1938-08-15 | 1938-08-15 | Improvements in and relating to electric communication systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB521340A true GB521340A (en) | 1940-05-20 |
Family
ID=10205010
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2401538A Expired GB521340A (en) | 1938-08-15 | 1938-08-15 | Improvements in and relating to electric communication systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB521340A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2489361A (en) * | 1945-05-02 | 1949-11-29 | Hartford Nat Bank & Trust Co | Multichannel carrier wave system employing multiple modulation |
EP0438075A2 (en) * | 1990-01-16 | 1991-07-24 | Alcatel SEL Aktiengesellschaft | Optical cable television transmission system |
-
1938
- 1938-08-15 GB GB2401538A patent/GB521340A/en not_active Expired
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2489361A (en) * | 1945-05-02 | 1949-11-29 | Hartford Nat Bank & Trust Co | Multichannel carrier wave system employing multiple modulation |
EP0438075A2 (en) * | 1990-01-16 | 1991-07-24 | Alcatel SEL Aktiengesellschaft | Optical cable television transmission system |
EP0438075A3 (en) * | 1990-01-16 | 1992-08-05 | Standard Elektrik Lorenz Aktiengesellschaft | Optical cable television transmission system |
US5162937A (en) * | 1990-01-16 | 1992-11-10 | Alcatel N.V. | Optical cable television transmission system |
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