Technique for simultaneous communications of analog frequency-modulated and digitally modulated signals using precanceling scheme
First Claim
Patent Images
1. Apparatus for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
- a controller for combining said second signal and a third signal derived from at least a waveform of said first signal to generate a combined signal; and
a transmit element for simultaneously transmitting said first signal and said combined signal over said frequency band, said third signal taking into account effects of said first signal on said combined signal when said first signal and said combined signal are simultaneously transmitted.
5 Assignments
0 Petitions
Accused Products
Abstract
In a system for simulcasting digitally modulated and analog FM signals over the same FM frequency band, the effect of the analog FM signal on the digitally modulated signal in the simulcast is calculated and canceled from the latter signal before its transmission. As a result, the digital transmission is free from interference from the analog FM signal. Moreover, the digital transmission is designed in such a manner that the interference caused thereby to the analog FM signal is kept at a minimal level.
-
Citations
40 Claims
-
1. Apparatus for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
a controller for combining said second signal and a third signal derived from at least a waveform of said first signal to generate a combined signal; and a transmit element for simultaneously transmitting said first signal and said combined signal over said frequency band, said third signal taking into account effects of said first signal on said combined signal when said first signal and said combined signal are simultaneously transmitted. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. Apparatus for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
a selector for selecting said second signal from a plurality of signals applicable to representing said second information; a controller responsive to said first signal for modifying said second signal; and a transmit element for simultaneously transmitting said first signal and the modified second signal over said frequency band, said second signal being selected to reduce effects of said modified second signal on said first signal when said first signal and said modified second signal are simultaneously transmitted. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A communications system for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
a transmitter comprising; a selector for selecting said second signal from a plurality of signals applicable to representing said second information; a controller responsive to said first signal for modifying the selected second signal; a first transmit element for simultaneously transmitting said first signal and the modified second signal over said frequency band, said second signal being selected to reduce effects of said modified second signal on said first signal when said first signal and said modified second signal are simultaneously transmitted; and a second transmit element for transmitting a control signal indicative of a presence of said selected second signal; and a receiver comprising; a first receive element for recovering said first information; and a second receive element responsive to at least said control signal for recovering said second information. - View Dependent Claims (18, 19, 20)
-
-
21. A method for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
generating a third signal based on at least a waveform of said first signal; combining said second signal and said third signal to generate a combined signal; and simultaneously transmitting said first signal and said combined signal over said frequency band, said third signal taking into account effects of said first signal on said combined signal when said first signal and said combined signal are simultaneously transmitted. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
-
-
30. A method for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
selecting said second signal from a plurality of signals applicable to representing said second information; modifying said second signal in response to said first signal; and simultaneously transmitting said first signal and the modified second signal over said frequency band, said second signal being selected to reduce effects of said modified second signal on said first signal when said first signal and said modified second signal are simultaneously transmitted. - View Dependent Claims (31, 32, 33, 34, 35, 36)
-
-
37. A method for communicating over a frequency band first information represented by a first signal and second information represented by a second signal comprising:
-
selecting said second signal from a plurality of signals applicable to representing said second information; modifying the selected second signal in response to said first signal; simultaneously transmitting said first signal and the modified second signal over said frequency band, said second signal being selected to reduce effects of said modified second signal on said first signal when said first signal and said modified second signal are simultaneously transmitted; transmitting a control signal indicative of a presence of said selected second signal; recovering said first information; and recovering said second information in response to at least said control signal. - View Dependent Claims (38, 39, 40)
-
Specification