Methods and arrangements for frequency shift communications by undersampling
First Claim
1. A method comprising:
- generating, by a frequency shift keying modulator, an output signal at a delimiter frequency, the delimiter frequency being between a first frequency and a second frequency, wherein the output signal at the delimiter frequency can facilitate demodulation of data to transmit, the data having bits associated with a first group and a second group, wherein the first group is associated with the first frequency and the second group is associated with the second frequency;
generating, by the frequency shift keying modulator, the output signal at the first frequency to transmit bits associated with the first group;
generating, by the frequency shift keying modulator, the output signal at the second frequency to transmit bits associated with the second group; and
applying, by the frequency shift keying modulator, the output signal to a light source to generate light comprising the data.
1 Assignment
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Accused Products
Abstract
Embodiments may provide a way of communicating via an electromagnetic radiator, or light source, that can be amplitude modulated such as light emitting diode (LED) lighting and receivers or detectors that can determine data from light received from the amplitude modulated electromagnetic radiator. Some embodiments may provide a method of transmitting/encoding data via modulated LED lighting and other embodiments may provide receiving/decoding data from the modulated LED lighting by means of a device with a low sampling frequency such as a relatively inexpensive camera (as might be found in a smart phone). Some embodiments are intended for indoor navigation via photogrammetry (i.e., image processing) using self-identifying LED light anchors. In many embodiments, the data signal may be communicated via the light source at amplitude modulating frequencies such that the resulting flicker is not perceivable to the human eye.
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Citations
25 Claims
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1. A method comprising:
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generating, by a frequency shift keying modulator, an output signal at a delimiter frequency, the delimiter frequency being between a first frequency and a second frequency, wherein the output signal at the delimiter frequency can facilitate demodulation of data to transmit, the data having bits associated with a first group and a second group, wherein the first group is associated with the first frequency and the second group is associated with the second frequency; generating, by the frequency shift keying modulator, the output signal at the first frequency to transmit bits associated with the first group; generating, by the frequency shift keying modulator, the output signal at the second frequency to transmit bits associated with the second group; and applying, by the frequency shift keying modulator, the output signal to a light source to generate light comprising the data. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An apparatus comprising:
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a modulator to generate an output signal at a delimiter frequency, the delimiter frequency being between a first frequency and a second frequency, wherein the output signal at the delimiter frequency can facilitate demodulation of data to transmit, the data having bits associated with a first group and a second group, wherein the first group is associated with the first frequency and the second group is associated with the second frequency;
generate the output signal at the first frequency to transmit bits associated with the first group; and
generate the output signal at the second frequency to transmit bits associated with the second group; andan amplitude modulation device to modulate the amplitude of power to apply to a light source at the frequency of the output signal to generate light comprising the data. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. An apparatus comprising:
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a light detector to detect light at a sampling frequency to produce samples; frequency logic to determine the apparent frequencies of modulation of the light based upon the samples, the apparent frequencies of modulation of the light being associated with bits of data, wherein the apparent frequencies of modulation of the light comprise a first frequency associated with a first logical value, a second frequency associated with a second logical value, and a delimiter frequency associated with a start of a transmission of a frame of data; and a data associator to detect a start of a transmission of the data based upon receipt of the delimiter frequency and to determine the data based upon determining the apparent frequencies of modulation of the light. - View Dependent Claims (17, 18, 19, 20, 21, 22)
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23. A method comprising:
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detecting light, by a light detector, at a sampling frequency to produce samples; determining, by frequency logic, the apparent frequencies of modulation of the light based upon the samples, the apparent frequencies of modulation of the light being associated with bits of data, wherein the apparent frequencies of modulation of the light comprise a first frequency associated with a first logical value, a second frequency associated with a second logical value, and a delimiter frequency associated with a start of a transmission of a frame of data; detecting, by a data associator, a start of a transmission of the data based upon receipt of the delimiter frequency; and determining, by the data associator, the data based upon determining the apparent frequencies of modulation of the light. - View Dependent Claims (24)
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25. A program product comprising:
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a storage medium comprising instructions to be executed by a processor-based device, wherein the instructions, when executed by the processor-based device, perform operations, the operations comprising; receiving samples produced from light detected by a light detector at a sampling frequency; determining, by frequency logic, the apparent frequencies of modulation of the light based upon the samples, the apparent frequencies of modulation of the light being associated with bits of data, wherein the apparent frequencies of modulation of the light comprise a first frequency associated with a first logical value, a second frequency associated with a second logical value, and a delimiter frequency associated with a start of a transmission of a frame of data; detecting, by a data associator, a start of a transmission of the data based upon receipt of the delimiter frequency; and determining, by the data associator, the data based upon determining the apparent frequencies of modulation of the light.
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Specification