Simultaneous transmission of an analog message signal and a digital data signal
US4401854A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 3, 1981 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Aug 3, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04K1/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In its most general form, the present invention may be employed to simultaneously transmit information, either digital or analog, from two separate and distinct sources, denoted A and B, where the information from at least one of the sources, for example, A, possesses some known statistical properties of coherence. The less coherent information from, for example, source B, is used to generate a set of scrambling key sequences, where each separate scrambling key sequence is associated with a unique segment of information from source B. The key sequences are used to scramble the information from source A, and the scrambled information is produced as the output of the transmitter. In one form, the information from source A could be an analog signal (x(t)) and the information from source B could be a digital data sequence ({d.sub.k }) which is capable of transmitting n data bits per every N samples of the analog signal from source A. In particular, each sequential block of N samples of the analog signal is scrambled in M unique ways (S.sub.1 -S.sub.M), where M=2.sup.n, and the M scrambled sequences are associated in a one-to-one relationship with the M possible combinations of data ele…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.