Multiplexed pulse modulation using superposition
The present invention relates to an optical transmitter for transmitting data. The optical transmitter includes a pulse generator for generating N data streams overlapping in time from a de-multiplexed data source. Each respective data stream has pulses with shapes unique to that respective data stream. The transmitter also includes an optical source optically transmitting an output pulse that is generated by summing the uniquely shaped pulses from each respective data stream that are overlapping in time. Each output pulse represents N bits of the data source, where N>1.
1. An optical transmitter for transmitting data, including:
a pulse generator generating N data streams overlapping in time from a de-multiplexed data source, each respective data stream having pulses with a common shape unique to that respective data stream, the common shape based on at least one of duty cycle, amplitude and phase shift;
an optical source optically transmitting an output pulse that is generated by summing the uniquely shaped pulses from each respective data stream that are overlapping in time, each output pulse representing N bits of the data source, where N>1; and
N light emitting diodes (LEDs) that transmit the N respective data streams, and
wherein the output pulse is generated by optically summing the uniquely shaped optical pulses transmitted from the N LEDs.
2. The optical transmitter of claim 1 , further comprising:
an adder that electrically sums the uniquely shaped pulses to produce the output pulse, and
wherein the optical source is a light emitting diode (LED) that transmits the output pulse.
3. The optical transmitter of claim 1 ,
wherein the N uniquely shaped pulses have unique duty cycles to produce 2 N output pulses.
4. The optical transmitter of claim 1 ,
wherein the N uniquely shaped pulses have unique amplitudes to produce 2 N output pulses.
5. An optical transmitter for transmitting data, including:
a pulse generator generating N data streams overlapping in time from a de-multiplexed data source, each respective data stream having pulses with a common shape unique to that respective data stream, the common shape based on at least one of duty cycle, amplitude and phase shift; and
an optical source optically transmitting an output pulse that is generated by summing the uniquely shaped pulses from each respective data stream that are overlapping in time, each output pulse representing N bits of the data source, where N>1, and
wherein the N uniquely shaped pulses have unique phases to produce 2 N output pulses.
6. The optical transmitter of claim 1 ,
wherein the N uniquely shaped pulses have at least two of unique duty cycles, unique amplitudes and unique phases to produce 2 N output pulses.