Overlaying digital signals on analog wireless communication signals
AssigneeLockheed Martin Corporation
InventorsFM Bay, Daniel J. Heil
Life of this patent
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Abstract
A method and system of providing digital communications over frequencies concurrently utilized for analog communications. In one embodiment, the method (400) includes the step of establishing (410) a digital channel including two or more analog channels that are concurrently used to provide analog communications. A spread spectrum digital waveform is generated (420) having its energy spread throughout the bandwidth of the digital channel. The spread spectrum digital waveform is modulated (430) to include information to be communicated digitally and transmitted (440) over the digital channel. The transmitted modulated spread spectrum digital waveform is received (450) and demodulated (460) to obtain the information.
Claims24
A method of providing digital communications over frequencies concurrently utilized for analog communications, said method comprising the steps of:
- establishing a digital channel including at least two contiguous analog channels concurrently used to provide analog communications, each analog channel being centered at a different frequency and having a bandwidth, the digital channel having a bandwidth corresponding to the sum of the bandwidths of the analog channels included in the digital channel, wherein an even number of analog channels are included in the digital channel whereby a center frequency of the digital channel does not coincide with center frequencies of any of the analog channels included in the digital channel;
- generating a spread spectrum digital waveform wherein energy of the spread spectrum digital waveform is spread throughout the bandwidth of the digital channel;
- modulating the spread spectrum digital waveform to include information to be communicated digitally;
- and
- transmitting the modulated spread spectrum digital waveform over the digital channel.
A system operable to provide digital communications over frequencies concurrently utilized for analog communications, said system comprising:
- at least one transmitter operable to select a digital channel including at least two contiguous analog channels concurrently used to provide analog communications, each analog channel being centered at a different frequency and having a bandwidth, the selected digital channel having a bandwidth corresponding to the sum of the bandwidths of the analog channels included in the digital channel, wherein an even number of analog channels are included in the digital channel whereby a center frequency of the digital channel does not coincide with center frequencies of any of the analog channels included in the digital channel, and wherein the at least one transmitter is further operable to generate a spread spectrum digital waveform wherein energy of the spread spectrum digital waveform is spread throughout the bandwidth of the digital channel, modulate the spread spectrum digital waveform to include information to be communicated digitally, and transmit the modulated spread spectrum digital waveform over the digital channel;
- and
- at least one receiver tunable to the digital channel and operable to demodulate the modulated spread spectrum digital waveform to obtain the information therefrom.
An apparatus for providing digital communications over frequencies concurrently utilized for analog communications, said apparatus comprising:
- means for selecting a digital channel including at least two contiguous analog channels concurrently used to provide analog communications, each analog channel being centered at a different frequency and having a bandwidth, the digital channel having a bandwidth corresponding to the sum of the bandwidths of the analog channels included in the digital channel, wherein an even number of analog channels are included in the digital channel whereby a center frequency of the digital channel does not coincide with center frequencies of any of the analog channels included in the digital channel;
- means for generating a spread spectrum digital waveform wherein energy of the spread spectrum digital waveform is spread throughout the bandwidth of the digital channel;
- means for modulating the spread spectrum digital waveform to include information to be communicated digitally;
- means for transmitting the modulated spread spectrum digital waveform over the digital channel;
- and
- means for receiving the modulated spread spectrum digital waveform on the digital channel and demodulating the modulated spread spectrum digital waveform to obtain the information therefrom.
Dependencies are inferred from the claim text.