OPTICAL DATA TRANSMISSION SYSTEM FOR SWIMMERS

Abstract

An underwater communication system, wherein the underwater communication system is capable of increasing a data transmission through a visible light between a surface and underwater of a swimming pool and an underwater communication method providing the data transmission between the surface and the underwater of the swimming pool are provided.

Claims

1. A data transmission system through a visible light for providing a data transmission between a surface and an underwater of a swimming pool, wherein the data transmission system comprises: at least one modulator configured to receive an audio signal from the audio source and configured to convert the audio signal into an electrical signal, at least one light sensor configured to receive optical signals from at least one light source and configured to convert a received optical signal into the electrical signal, at least one audio converter configured to convert a data signal into the audio signal, and at least one output unit configured to play back the audio signal generated by the at least one audio converter, wherein at least one digital audio source configured to transfer the audio signal from stored data or stream data, the at least one light source configured to receive the electrical signal from the at least one modulator and configured to convert the electric signal into the received optical signal, wherein the at least one light source of the data transmission system is configured to be placed on a ceiling and/or surrounding wall and/or sides and/or bottom of an indoor swimming pool, and at least one demodulator providing a baseband processing of multiple received electrical signals to retrieve the data signal.

2. The data transmission system according to claim 1, wherein the at least one modulator comprises electronic circuits configured to convert digital data into an electrical waveform applied to the at least one light source.

3. The data transmission system according to claim 2, wherein the at least one audio source is a sound sensor or a microphone followed by an analogue to digital audio signal converter.

4. (canceled)

5. (canceled)

6. The data transmission system according to claim 1, wherein the at least one light source comprises one or more light emitting diode.

7. The data transmission system according to claim 1, further comprising one or more light sensors configured to be clipped to a belt, or worn on an armband, or positioned on a swimsuit, or goggles of a person under water.

8. The data transmission system according to claim 1, further comprising a plurality of light sources and a plurality of light sensors configured to provide multiple input and multiple output communication (MIMO) between the plurality of light sources and the plurality of light sensors.

9. The data transmission system according to claim 1, wherein the at least one output unit comprises waterproof headsets.

10. The data transmission system according to claim 1, further comprising a channel selector configured to select a received signal transferred from a plurality of digital audio sources (10) and correspond to a channel chosen by a user.

11. (canceled)

12. An optical data transmission method performed by a system according to claim 1, comprising the following steps: modulating a digital audio signal to be transmitted to a swimmer and feeding the digital audio signal to a plurality of light sources, converting an electrical signal received from each of the plurality of light sources into an optical signal, demodulating the electrical signal received either from a selected sensor or combine output and retrieving the data signal, and playing back the audio signal by an output unit, wherein propagating the optical signals emitted from the plurality of light sources through water and transmitting the optical signals to the swimmer, collecting aggregated optical signals by each light sensor and converting the aggregated optical signals into the electrical signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 Flow chart of the data transmission system without channel selector.

[0030] FIG. 2 Flow chart of the data transmission system with channel selector.

[0031] 1. Data transmission system [0032] 10. Digital audio source [0033] 11. Modulator [0034] 12. Light sources [0035] 13. Light sensors [0036] 14. Demodulator [0037] 15. Channel selector [0038] 16. Audio converter [0039] 17. Output unit

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present invention provides a method and a system for data transmission between the underwater and the surface of a swimming pool.

[0041] A data transmission system (1) for use in a swimming pool to provide data transmission through visible light between the surface and the underwater, comprises at least one digital audio source (10) transferring an audio signal from the stored data or stream data, at least one modulator (11) converting the audio signal to electrical signal, at least one light source (12) converting the electrical signal into optical signal, at least one light sensor (13) receiving the optical signals from the light source (12) and converting received and aggregated optical signal into electrical signal, at least one demodulator (14) providing a baseband processing of multiple received electrical signals to retrieve the data signal, at least one audio converter (16) converting the data signal into an audio signal and at least one output unit (17) playing back audio signals generated by the audio converter (16). (References: (1) M. Uysal, C. Capsoni, Z. Ghassemlooy, A. C. Boucouvalas, E. G. Udvaiy (Eds.), Optical Wireless Communications-An Emerging Technology, Springer 2016, (2) S. Dimitrov and H. Haas, Principles of LED Light Communications: Towards Networked Li-Fi“, Cambridge University Press 2015, (3) Z. Zeng, S. Fu, H. Zhang, Y. Dong and J. Cheng, A Survey of Underwater Optical Wireless Communications,” IEEE Communications Surveys & Tutorials, 2017).

[0042] In one embodiment of the present invention, the digital audio source (10) may include stored digital audio signals such as stored music, stored podcasts and audio books and/or a stream data in real time such as music, radio channels, several program channels and media streaming applications or the speech or instructions of the coach who is on the surface. In one embodiment of the present invention, modulator (11) receives an audio signal transferred from the digital audio source (10) and converts the audio signal into an electrical signal. Modulator (11) has electronic circuits converting digital data into an electrical waveform that can be applied to a light source (12).

[0043] In one embodiment of the present invention sound sensors or microphone are used as the audio signal source followed by an analogue to digital (A/D) audio signal converter whose output is applied to the modulator (11).

[0044] In one embodiment of the present invention there are several program channels and some of them are reserved for coach and swimmer communication in real time. When coach gives instructions to the swimmer, voice of the coach is converted to digital form by microphones and data to be forwarded to the swimmer is sent through the selected channel.

[0045] In another embodiment of the present invention information appliance used by the coach runs a specially configured media streaming application. This application is used by a coach in real-time as the swimmer is performing the activity. One of the functions of the application is to provide the coach with the ability to select an individual swimmer to communicate with, and then to translate his/her voice to digital form and send the data to be forwarded to the particular swimmer.

[0046] In one embodiment of the present invention, the wireless transmission capabilities can include optical transmission. The light source (12) serves as a wireless transmitter. The light source (12) receives the electrical signals from modulator (11) and converts into optical signals.

[0047] The light source (12) is configured to receive the electrical signal from the modulator (11) and to adjust intensity of the optical illumination signal. Subsequently, the light source (12) receives electrical signal and illumination signal and gathering these two signals to generate a complex light signal. After that it adjusts a wavelength of the complex light signal to emit a visible light signal to underwater.

[0048] In one embodiment of the present invention; data transmission system (1) provides optical data transmission between the swimmer in the swimming pool and the surface. Swimming pool is an indoor swimming pool. According to one embodiment of the present invention, at least one light source (12) is placed at the ceiling of the indoor swimming pool.

[0049] The light sources (12) are already placed at the sides and/or bottom of the swimming pool at a certain distance to each other and in one embodiment of the present invention the light sources (12) can be configured to used for data transmission between the surface and the underwater of the swimming pool. In one embodiment of the present

[0050] invention, the data transmission system (1) is configured to include at least one light sensor (13).

[0051] The light sensor (13) is configured to receive and amplify the visible light signal emitted from the light source (12) to the underwater. The received and amplified visible light signal is converted into an electrical signal so that the visible light signal may be easily output.

[0052] The light sensor (13) is preferably provided on the swimmer. The light sensor (13) can be clipped to a belt, or worn on an armband or on a swimsuit or swimmers' goggles. Thus, optical signals emitted from the light sources (12) propagate through water and reach to the swimmer.

[0053] Each light sensor (13) receives the light signals from multiple light sources (12) and converts the aggregated optical signal into electrical signal.

[0054] In one preferred embodiment of the present invention multiple light sources (12) and multiple light sensors (13) on the same swimmer are used to enable robust performance in the presence of shadowing or blockage due to swimmer movements. In the present invention, MIMO (M. V. Jamali; P. Nabavi; J. A. Salehi,” MIMO Underwater Visible Light Communications: Comprehensive Channel Study, Performance Analysis, and Multiple-Symbol Detection“, 2018) communication makes data transmission possible even if one or more light sensors are completely blocked by swimmer arm. The MIMO technology is originally developed for RF transmission between multiple transmission and reception antenna. In this application, the multiple light sources and multiple light sensors are being used instead of antennas as explained in M. V. Jamali; P. Nabavi; J. A. Salehi,” MIMO Underwater Visible Light Communications: Comprehensive Channel Study, Performance Analysis, and Multiple-Symbol Detection”, 2018.

[0055] In one embodiment of the present invention, demodulator (14) provides a baseband processing of multiple received electrical signals from the light sensors (13) to retrieve the data signal. In the present invention, the output of light sensors (13) can be processed in two different ways; [0056] The light sensor (13) with highest signal to noise ratio is selected or [0057] The outputs can be combined through maximal ratio combining where the signals from each receiver are multiplied with proper weighting coefficients based on the available channel state information and a weighted sum is obtained.

[0058] The electrical signal either from the selected sensor or combiner output is demodulated by demodulator (14) and data signal is retrieved.

[0059] The audio converter (16) converts the received data signal into an audio signal and the output unit (17) plays back audio signals generated by the audio converter (16).

[0060] In one embodiment of the present invention, data transmission system comprises an output unit or device playing back the audio signal. The output unit may be waterproof headsets such as headphones. The output unit (17) may also be any device found in the prior art capable of outputting various signals.

[0061] In one embodiment of the present invention, the data transmission system further comprises a channel selector (15). In that case the audio source (10) includes stream data signal that can be selected by the swimmer in real time such as music, radio channels, several program channels and media streaming application. “Channel” is chosen by the swimmer, and thus, the received signal corresponds to channel chosen by the swimmer. In these circumstances the channel selector (15) selects the received signal transferred from the audio source (10) and correspond to a channel chosen by the swimmer. The audio converter (16) converts the selected signal into an audio signal and the output unit (17) plays back audio signals generated by the audio converter (16).

[0062] The present invention further provides an optical data transmission method (100) comprising the following steps: [0063] modulating the digital audio signal to be transmitted to the swimmer and feeding the digital audio signal to multiple light sources (12), [0064] converting the electrical signal received from each light source (12) into optical signal, [0065] propagating the optical signals emitted from light sources (12) through water and transmitting the optical signal to the swimmer, [0066] collecting the aggregated optical signals by each light sensor (13) and converting it into an electrical signal, [0067] demodulating the electrical signal either from the selected sensor or combine output and retrieving the data signal, and [0068] playing back the audio signal by an output unit (17).