Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
  • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
  • H04B10/114—Indoor or close-range type systems
  • H04B10/116—Visible light communication

Definitions

• the present invention relates to the field of the transmission of optical radiation and, in detail, it relates to a system for transmitting data by means of optical radiation by means of diffusion by power lines.
• the present invention also relates to an associated method for diffusing data. BACKGROUND ART
• a first problem is that radio transmissions often use radio channels which are overlapped or, in any case, interfering with the transmission spectra of adjacent channels, or with other sources of interference geographically allocated in a position different with respect to those of interest.
• radio transmissions at very high frequencies is also subject to a considerable atmospheric absorption, the latter being, in fact, substantially increasing as the frequency in the radio frequency spectrum increases; consequently to transmit electronic data on broadband at very high frequencies, it is typically necessary to employ significantly high transmission powers.
• radio transmissions are conventionally employed, which allow the signal on which said data are transmitted to pass through the physical barriers of an apartment - walls, floors - without the need for wiring.
• the most typical example of such types of transmissions is that given by WiFi networks, where electronic data are transmitted from a modem or access point to further wireless modems installed on board the various electronic devices which are employed daily by users.
• power lines are also known, i.e., those technological applications for the transmission of electronic data which use electricity power supply and distribution cables already arranged in buildings as transmission mediums.
• the electronic data is transmitted by overlapping an electrical signal with a significantly higher frequency with respect to the frequency - typically 50 Hz or 60 Hz, depending on the country - of the alternating mains voltage.
• the separation of the electrical signal which carries the data of interest with respect to the mains voltage occurs by means of filtering and separating the frequencies used.
• said cabled connection on said power network (400) of said at least one first optical transmitting module (99) is a connection in which said optical transmitting module (99) is physically connected to said pair of power supply cables (F, N) electrically isolated from each other.
• said method comprises a step of receiving said optical radiation (108) by at least one first optical receiving module (199), comprising at least one demodulating stage (201 ), or optical demodulating stage, in which it demodulates said optical radiation to extract at least one replica of said data signal (s(t)).
• a mains voltage (v(t)) is present and/or said pair of cables (F, N) is configured to transmit a mains voltage (v(t)) simultaneously, and/or overlapping, said data signal (s(t)).
• a step of filtering an electrical signal including said data signal (s(t)), and/or of filtering said data signal (s(t)) from the mains voltage in which said step of filtering operates a frequency selection centred on a predetermined band of frequencies, which is separate from the band of frequencies in which said mains voltage (v(t)) lies, and/or in which, through the step of filtering, a frequency selection centred on a predetermined band of frequencies is controlled, said predetermined band of frequencies being separate from the band of frequencies in which said mains voltage (v(t)) lies.
• said step of modulating is an amplitude modulating step.
• said step of modulating is a frequency modulating step.
• said step of modulating is a pulse width modulating step.
• the step of modulating is a hybrid modulating step, in which the modulation comprises an amplitude modulation and a frequency modulation.
• said step of modulating is, or comprises, a step of varying the polarization angle of the optical radiation emitted by a photoemitter (100) of said first optical transmitting module (99).
• said step of modulating is a step of modulating comprising:
• said step of modulating an optical radiation is executed by means of an optical transmitting module (99) integrated in a body of a lighting device (99c).
• the lighting device (99c) is a lamp, or light bulb, preferably a LED lamp or light bulb.
• the radiation intensity (lr(t)) is made variable according to said pilot signal, and comprises a first continuous part (I), which is independent from said pilot signal, and a second part which is variable over time as a direct function of said pilot signal (v7(t), i7(t)).
• said part which is variable over time as a direct function of said pilot signal (v7(t), i7(t)) is less in absolute value than the absolute value taken on by said first continuous part (I).
• said step of modulating an optical radiation comprises activating a photoemitter (100) of said optical transmitting module (99), powering it with said data signal (s(t)) and/or with said pilot signal (v7(t), i7(7)).
• said photoemitter is a broadband bandwidth LED.
• the radiation intensity (lr(t)) is made variable according to said pilot signal, and in the absence of said pilot signal, and/or if said pilot signal is at least temporarily null, the radiation intensity (lr(t)) is different from zero or comprises a residual component different from zero, in particular, only comprising said first continuous part (I).
• said residual component different from zero comprises and/or coincides with said first continuous part (I).
• said method comprises a step of generating a first reference frequency (fO) for said amplitude modulation.
• said method comprises a step of generating a first reference frequency (fO) for said amplitude modulation and a second reference frequency (fc) for said frequency modulation.
• the step of generating said first reference frequency and/or said first and said second reference frequencies is executed by means of powering an AM modulator (102) and/or an AM modulator (102) and a FM modulator (103) with a reference frequency generator (109).
• an optical transmitting device comprising:
• At least one photoemitter (100) configured to transmit, in use, a modulated optical radiation (108);
• a filtering stage (217) having an own input electrically connected to said at least one pair of inputs (99d), said filtering stage being configured to separate, by means of a frequency selection, a data signal (s(t)) of the electrical type from a mains voltage (v(t)), in use, present on said pair of inputs (99d) simultaneously to said data signal (s(t)), and to produce on an output thereof said data signal
• a modulating stage (101 ) operatively connected with the output of said filtering stage (217), comprising at least one operative configuration in which it generates an electrical pilot signal (v7(t), i7(t)) for said at least one photoemitter (100) modulated according to a predefined modulation scheme based on said data signal (s(t)).
• said at least one photoemitter (100), said filtering stage (217) and said modulating stage (101 ) are enclosed in a single body.
• said device further comprises a decoupling stage (216) interposed between said pair of inputs (99d) and said modulating stage (101 ) and having inputs directly connected to said pair of inputs (99d), said decoupling stage (216) comprising a voltage transformer.
• said modulating stage (101 ) is an amplitude modulating stage.
• said modulating stage (101 ) is a frequency modulating stage.
• said modulating stage (101 ) is a pulse amplitude modulating stage. Still alternatively, according to a further non-limiting aspect, said modulating stage (101 ) is a hybrid stage, comprising:
• an input (105) adapted to receive, in use, an electrical signal (s(t)) to be modulated, and, in particular, said data signal (s(t)) of the electrical type, and
• an output (107) transmitting a voltage or current pilot signal (v7(t), i7(t)) towards said at least one photoemitter (100), for which said electrical signal (s(t)), and, in particular, said data signal (s(t)) of the electrical type, represents a modulating signal, where said at least one photoemitter (100) transmits an optical radiation (108) with variable radiation intensity (lr(t)) according to said pilot signal (v7(t), i7(t)).
• a cascade of a first AM modulator (102) and of a second FM modulator (103) is present, said FM modulator (103) being placed downstream of said AM modulator (102) and having an own output directly connected to the output (107) of said modulating stage (101 ), in which said AM modulator (102) has an input directly connected to said input (105) of said modulating stage and is directly powered by means of said electrical signal (s(t)) to be modulated, and in which said AM modulator (102) has an output on which it generates an intermediate signal (s2(t)) powered at input at said FM modulator (103).
• a piloting stage (104) is further present, for said at least one photoemitter (100) interposed between said output (107) of said modulating stage (101 ) and said at least one photoemitter (100), in which said piloting stage (104) is configured to influence said pilot signal (v7(t), i7(t)) and comprises processing means comprising at least one operative configuration such that said variable radiation intensity (lr(t)) according to said pilot signal comprises a first continuous part (I), independent from said pilot signal, and a second part which is variable over time as a direct function of said pilot signal, in which said part which is variable over time as a direct function of said pilot signal, is less in absolute value than the absolute value taken on by said first continuous part.
• said photoemitter (100) is a semiconductor photoemitter, in particular, a broadband LED photoemitter, optionally, a LED photoemitter of the GaN type or a SLED.
• said photoemitter (100) is a laser.
• said modulating stage (101 ) is a hybrid stage, preferably configured to modulate said data signal (s(t)) in amplitude and/or in frequency, comprising:
• an input (105) adapted to receive, in use, an electrical signal (s(t)) to be modulated, and, in particular, said data signal (s(t)) of the electrical type, and
• said part which is variable over time as a direct function of said pilot signal is less in absolute value than the absolute value taken on by said first continuous part.
• the radiation intensity (lr(t)) is different from zero or comprises a residual component different from zero.
• said residual component different from zero comprises and/or coincides with said first continuous part (I).
• said intermediate signal (s2(t)), powered at input to said FM modulator (103), is a signal adapted to cause a variation in the instantaneous frequency which said pilot signal (v7(t)), i7(t)) takes on at the output of the FM modulator (103).
• said device comprises at least one stage of generating a reference frequency (109), in which said stage of generating a reference frequency (109) is electrically connected to a reference frequency input of said AM modulator (102) and generates at least one first reference frequency (fO) for said AM modulator.
• said stage of generating a reference frequency (109) is electrically connected to a reference frequency input of said AM modulator (102) by means of a first output (109f) thereof, and is further electrically connected to a reference frequency input of said FM modulator (103) by means of a second output (109s) thereof.
• said stage of generating a reference frequency (109) generates at least one first reference frequency (fO) for said AM modulator (102) and a second reference frequency (fc) for said FM modulator (103).
• said device further comprises at least one photoreceiver (200) electrically connected to a demodulating stage (201 ), said demodulating stage (201 ) receiving, in use, an electrical pilot signal (v7(t), i7(t)) generated by said at least one photoreceiver (200) and comprising at least one operative configuration in which it generates, on an output thereof, an output replica signal (s'(t)), said output replica signal representing a data signal used to modulate an optical radiation received by said photoreceiver (200).
• an electrical pilot signal v7(t), i7(t)
• s'(t) an output replica signal
• said output replica signal representing a data signal used to modulate an optical radiation received by said photoreceiver (200).
• said demodulating stage (201 ) is an amplitude demodulating stage.
• said demodulating stage (201 ) is a frequency demodulating stage.
• said demodulating stage is a pulse amplitude demodulating stage.
• said demodulating stage is a hybrid demodulating stage comprising:
• said demodulating stage comprises an output electrically connected to a secondary circuit of the decoupler (216).
• said decoupler (216) is a voltage- reducing transformer in which the average voltage on the secondary circuit is less with respect to the average voltage present on the primary circuit.
• optical transmitting device is described, according to one or more of the aspects described herein, for the transmission of multimedia data signals.
• an optical radiation system for diffusing data comprising,
• a device for injecting an electrical data signal (s(t)) comprising at least one pair of connectors adapted to be electrically connected on a power network (400), and
• said injecting device is an optical transmitting device according to one or more of the preceding aspects.
• optical radiation means an optical radiation comprised in the infrared spectrum and/or in the ultraviolet spectrum and/or in the visible spectrum.
• direct optical radiation or direct optical transmission means a transmission of an optical radiation in which between a source or photoemitter and a destination or photoreceiver no optically opaque obstacles are interposed and no reflections are present.
• the transmission of the signals occurs with said source or photoemitter and the destination or photoreceiver being within the optical range, i.e., mutually visible.
• Transparency means a feature such that the material under examination may allow a radiation, which is incident thereon, to pass along a preferential direction, independently of the attenuation that such radiation undergoes in the passage through said material.
• Infrared means an electromagnetic radiation which has a wavelength approximately from 0.7 pm to 15 pm.
• Visible or “visible spectrum” means an electromagnetic radiation which has a wavelength approximately from 390 to 700 nm.
• Ultraviolet means an electromagnetic radiation which has a wavelength approximately from 400 nm to 10 nm.
• Directive irradiation or even only “directive”, when referred to an optical and/or radio frequency radiation, means a radiation emitted by a radiator in the domain of interest - therefore, optical or radio frequency - in which a sector of the sphere of an otherwise isotropic radiator has a radiated electromagnetic power density which is higher with respect to the remaining sectors.
• FIG. 1 shows a block diagram of a device in accordance with the invention, operating according to the method described above, in an embodiment thereof, preferably, but not by way of limitation, in the form of a light bulb;
• FIG. 2 shows a first alternative and non-limiting solution for the modulator present in the device in accordance with the invention
• FIG. 5 shows a fourth alternative and non-limiting solution for the modulator present in the device in accordance with the invention.
• - Figure 6 shows a more detailed diagram for the fourth alternative and non-limiting solution for the modulator present in the device in accordance with the invention
• - Figure 7 shows an alternative and non-limiting embodiment of the device in accordance with the invention in which a modulator and also a demodulator for the optical radiation is present;
• optical transmitting device shown in Figure 1 in a non-limiting embodiment thereof.
• Such device is equipped with at least one photoemitter 100 adapted to transmit, in use, a modulated optical electromagnetic radiation 108, in particular an optical radiation in the visible and/or infrared and/or ultraviolet spectrum.
• the optical transmitting device which in a preferred and non-limiting embodiment takes on the form of a light bulb 99 equipped with a body 99 and with a portion 99c adapted to emit an optical radiation, has at least one pair of inputs 99d for powering the photoemitter 100 by means of the electricity coming from the power network of a building.
• a data signal s(t) of the electrical type travels, overlapping a mains voltage v(t).
• the inputs 99d are connected on a socket 401 , in turn connected to a power network, preferably, but not by way of limitation, to the domestic power network 400 of an apartment.
• the mains voltage v(t) may be a mains voltage of the continuous or alternating type, characterized in this case by an own carrier frequency.
• the data signal in particular, may be a multimedia data signal, i.e., a data signal containing audio and/or video data.
• the photoemitter 100 may either be a consistent photoemitter - by "consistent” meaning a monochromatic photoemitter, as it may be a LASER - or an inconsistent one - by “inconsistent” meaning a photoemitter emitting a polychromatic optical beam, meaning, for example, of white light or of any colour, not distinguished by high spectral purity, such as, for example, a LED diode or a SLED one.
• the device object of the invention may comprise a plurality of high-power photoemitters 100 which, advantageously allow to illuminate, for example, a room.
• the Applicant has observed that the LED diodes may be employed even if the use of an extremely high bandwidth is requested, up to ranges of several hundred MHz, for example, up to 800 MHz or 900 MHz.
• GaN LED diodes, or broadband diodes such as SLEDs, may be employed in the optical transmitting device described herein.
• the use of SLEDs or LEDs, also of the GaN type allows to reduce costs with respect to the employment of a laser.
• the optical transmitting device has a filtering stage 217 having an own input electrically connected to the inputs 99d.
• the filtering stage is configured to separate, by means of a frequency selection, a data signal s(t) of the electrical type from a mains voltage v(t), in use, present on the inputs 99d simultaneously to said data signal s(t), and to produce on an output thereof said data signal s(t) isolated from said mains voltage v(t).
• the band of frequencies on which the data signal s(t) is transmitted on the domestic power network 400 is a band of frequencies separate with respect to the band of frequencies on which the electrical signal of the mains voltage v(t) is transmitted; suitably, the selection of an appropriate guard interval between the two bands may be provided for, which advantageously allows an optimization of the filtering and/or prevents, or in any case helps to reduce, the influence of the oscillation of the mains voltage v(t).
• the optical transmitting device which in the embodiment of Figure 1 is identified by means of a light bulb or of an equivalent lighting device, comprises at least one optical transmitting module 99 which comprises the photoemitter 100 and at least one modulating stage 101 .
• the modulating stage 101 is operatively connected with the output of the filtering stage 217, comprising at least one operative configuration in which it generates an electrical pilot signal v7(t), i7(t) for the photoemitter 100 modulated according to a predefined modulation scheme based on said data signal s(t).
• the photoemitter 100, said filtering stage 217 and said modulating stage 101 are enclosed in a single body by virtue of which they may be easily handled.
• the device object of the invention further comprises a decoupling stage 216 interposed between the inputs 99d and the modulating stage 101 having inputs directly connected to said pair of inputs 99d.
• the modulator 101 is an amplitude modulating stage.
• the modulator 101 may be a FM frequency modulating stage ( Figure 3) or a pulse amplitude modulating stage ( Figure 4).
• the modulating stage 101 is a stage comprising: - an input 105 adapted to receive, in use, an electrical signal s(t) to be modulated, and
• the modulating stage 101 is a hybrid stage, i.e., it is a stage which realises a hybrid modulation comprising an amplitude modulation and a frequency modulation.
• the amplitude and frequency modulations are realised in cascade, preferably and not by way of limitation, in the form which is described below.
• the Applicant has observed that such hybrid modulation may be advantageously used on broadband bandwidth LED diodes, in particular and not by way of limitation, as those described above.
• the photoemitter 100 transmits an optical radiation 108 with variable radiation intensity Ir (t) according to said pilot signal v7(t), i7(t), and between said input and said output of said modulating stage 107 a cascade of a first AM modulator 102 and of a second FM modulator 103 is present.
• the FM modulator 103 being placed downstream of the AM modulator 102, has an own output directly connected to the output 107 of the modulating stage 101 .
• the Applicant has observed that the use in cascade of an AM modulation followed by an FM modulation for an optical signal allows an optimal diffusion thereof in the environment and a remarkable ease of reception of optical radiations which - in the whole radiation spectrum typical of optical signals as defined above - may be conveniently received and demodulated not only upon direct transmission, but also upon reflected transmission by means of one or more reflections or diffusions by one or more surfaces.
• the AM modulator 102 has an input directly connected to the input 105 of the modulating stage and is directly powered by means of said electrical signal s(t) to be modulated.
• the AM modulator 102 has an output on which it generates an intermediate signal s2(t) powered at input to said FM modulator 103.
• a piloting stage 104 interposed between the output 107 of the modulating stage 101 and the photoemitter 100 is also present.
• the piloting stage 104 is configured to influence said pilot signal v7(t), i7(t) and comprises processing means which operate so that, in at least one operative configuration, the variable radiation intensity lr(t), in accordance with the pilot signal, comprises a first continuous part I, independent of said pilot signal, and a second part which is variable over time, as a direct function of the pilot signal itself.
• the radiation intensity lr(t) is different from zero or comprises a residual component different from zero.
• Such residual component may comprise and/or coincide with the first continuous part I; in particular, such continuous part may take on the function of mere illumination, and therefore be derived from the mains voltage (v(t)).
• the part which is variable over time as a direct function of said pilot signal is less in absolute value than the absolute value taken on by said first continuous part. In practical terms, this translates into the fact that, at least during the signal modulation, i.e., under active use in transmission conditions, the photoemitter 100 is never completely switched off.
• the intermediate signal s2(t) powered at input to the FM modulator 103 is a signal adapted to cause a variation in the instantaneous frequency which the pilot signal v7(t), i7(t) takes on at the output of the FM modulator 103.
• the modulator 101 also comprises a stage of generating a reference frequency 109, electrically connected to a reference frequency input of the AM modulator 102, and generates at least one first reference frequency fO for the AM modulator.
• the stage of generating a reference frequency 109 is electrically connected to a reference frequency input of said AM modulator 102 by means of a first output 109f thereof, and is further electrically connected to a reference frequency input of said FM modulator 103 by means of a second output 109s thereof.
• the stage of generating a reference frequency 109 When the carrier frequencies of the AM component are to be separated from the FM component, the stage of generating a reference frequency 109 generates at least one first reference frequency fO for said AM modulator 102 and a second reference frequency fc for said FM modulator 103.
• At least parts of the modulating stage in particular of the AM modulator, the FM modulator and/or the pulse width modulator, may be realised as hardware or with a mixed hardware software structure or again as SDR, therefore purely as software, without such difference constituting a limitation for the purposes of the present invention.
• the optical transmitting module may be configured to transmit an optical radiation comprising a variation of the polarization angle of the optical radiation emitted by the photoemitter 100, in particular - although, not by way of limitation - so that the variation over time of the polarization angle occurs according to the data signal s(t) and/or to the pilot signal.
• the device object of the invention may further comprise a demodulator comprising a photoreceiver 200 electrically connected to an optical receiving module 199.
• a demodulator comprising a photoreceiver 200 electrically connected to an optical receiving module 199.
• the optical receiving module 199 is integrated in the same body in the which the modulator and the inputs 99d are integrated.
• the optical receiving module 199 is configured to demodulate the optical signal received by the photoreceiver 200 and to transmit on an output thereof a replica electrical signal s'(t).
• the optical receiving module 199 may integrate an AM demodulator.
• the optical receiving module 199 may integrate a FM or PWM demodulator, in particular, a phase demodulator which is configured and/or devised to realise a frequency demodulation.
• the optical receiving module 199 may integrate a hybrid demodulator of amplitude and frequency modulated signals, i.e., a demodulator adapted to realise a frequency demodulation and an amplitude demodulation.
• the photoreceiver 200 is electrically connected to a demodulating stage 201 , and, in use, receives an electrical pilot signal v7(t), i7(t) generated by the photoreceiver 200.
• the demodulator 201 generates on an output thereof an output replica signal s'(t) which represents a data signal used to modulate an optical radiation receive by the photoreceiver 200.
• the demodulating stage is a hybrid demodulating stage comprising:
• an input 205 adapted to receive, in use, a voltage or current pilot signal v7(t), i7(t) modulated and generated by means of a photoreceiver 200 connected thereto and receiving, in use, an even reflected optical radiation 108, and - an output 207 transmitting an output replica signal s'(t) for which the electrical signal (s(t)) represents a modulating signal,
• the FM demodulator 203 is placed upstream of the AM demodulator 202, which, in turn, has an input directly connected to the output of said FM demodulator 203.
• the hybrid demodulating stage as described above is particularly adapted to receive with a correct demodulation of the modulating signal, optical radiations 108 received indirectly, by means of multiple reflections or even diffusions, without a direct optical path being present between the radiation source and the photoreceiver 200.
• the demodulating stage comprises an output electrically connected to a secondary circuit of the decoupler 216.
• the decoupler 216 preferably, but not by way of limitation, is a voltage- reducing transformer equipped with a primary connected to the inputs 99d of the device object of the invention and to a secondary connected to the optical modulating stage 99 and, when present, to the optical demodulating stage 199.
• decoupler 216 When such decoupler 216 is a voltage-reducing stage, the average voltage on the secondary circuit is less with respect to the average voltage present on the primary circuit. By virtue of this feature, it is possible to realise a device particularly safe to use and handle.
• connection of the decoupler 216 both to the optical transmitting module 99 and to the optical receiving module 199 allows the device object of the invention not only to become a means of diffusion of a modulated optical radiation, but also to become a device which allows the injection on the domestic power network 400 of a data signal received starting from a further signal, in turn, of the optical type.
• a first step of the method for diffusing electronic data by means of optical radiation comprises, first of all, a step of creating a data signal s(t) by means of the introduction and/or modulation thereon of electronic data.
• electronic data are electronic data of an audio signal.
• the data signal s(t) is therefore, preferably but not by way of limitation, an electrical data signal.
• the data signal s(t) is then injected on the domestic power network 400 by means of a known procedure.
• the injection of the data signal s(t) on the domestic power network 400 may occur by means of a cabled transmission.
• the method which is the object of the invention comprises a diffusion of the data signal s(t) in the form of a preferably voltage signal, along the whole domestic power network 400, so that it diffuses to one or more electrical current sockets 401 electrically connected to the domestic power network, thus overlapping the electric voltage present on the domestic power network.
• the method further comprises a step of receiving the data signal s(t), overlapping the voltage or current signal, at the electrical current socket 401 , and, by means of a connection of the known type, is transmitted to the inputs 99d of the device or light bulb 99c object of the invention.
• the electrical signal is first subjected to a filtering step by means of the decoupling stage 216 preferably realised by means of the previously described transformer, together with the filtering stage 217.
• the purpose of these two stages is to lower the voltage at which the modulator and the demodulator cooperate and, furthermore, to separate the useful component of the data signal s(t) from the 50/60Hz component typical of the mains voltage of domestic appliances.
• the mains voltage v(t) is not alternating, but on the contrary is a continuous voltage, such filtering stage 217 may not be present.
• the method provides for a step of modulating an optical radiation 108 generated by at least one first optical transmitting module 99 by means of the data signal s(t) thus extracted from the voltage signal present on the domestic power network 400.
• the data signal acts as a modulating signal for the aforesaid optical radiation.
• the modulation of the optical signal follows, in particular, the predefined modulation scheme described above.
• connection cabled on said power network of said at least one first optical transmitting module is a connection in which the optical transmitting module 99 is physically connected to the pair of power supply cables electrically isolated from each other.
• the method which is the object of the present invention also has a step of receiving an optical radiation 108 by at least one first optical receiving module 199 comprising at least one demodulating stage 201 , in which it demodulates said optical radiation to extract at least one replica of said data signal s(t).
• the method object of the invention also comprises a step of filtering said electrical signal from the mains voltage v(t), in which said step of filtering operates a frequency selection centred on a predetermined band of frequencies, separate from the band of frequencies in which said mains voltage v(t) lies.
• step of filtering is operatively carried out by the filtering stage 217.
• the step of receiving said optical radiation 108 is operatively followed by a demodulating step according to a predefined demodulation scheme, which preferably, but not by way of limitation, follows the modulation scheme which is also operatively used for modulating the data signal s(t).
• a demodulating step according to a predefined demodulation scheme which preferably, but not by way of limitation, follows the modulation scheme which is also operatively used for modulating the data signal s(t).
• a replica data signal s'(t) is generated, which is transmitted, and optionally, but not by way of limitation, injected in the domestic power network 400.
• the step of receiving the optical radiation 108 by the device object of the invention is therefore followed by a step of injection of the replica signal s'(t) of the data signal s(t) with which the optical radiation 108 received has been modulated, within the domestic power network 400.
• the replica signal s'(t) is first passed into the secondary stage of the decoupler 216, from which it passes to the primary stage of the same decoupler, thus being capable of being injected and diffused on the domestic power network.
• the Applicant also found that in the injection step, through the passage from the secondary to the primary of the decoupler 216, it is possible to increase the voltage value of the replica signal s'(t) injected in the domestic power network. In doing so, the energy request which is demanded for the "creation" of the replica signal s'(t) is moderate, and at the same time, following the step of voltage increase which is brought about by the passage of the replica signal s'(t) from the secondary to the primary of the decoupler, it is advantageously possible to optimize the noise immunity of the system.
• the injection on the network of a replica signal s'(t) which is voltage-increased by virtue of the passage from the secondary to the primary of the decoupler makes the signal/noise ratio greater with respect to what it would have been if the replica signal s'(t) was not voltage-increased, allowing a diffusion of the replica signal s'(t) correctly distinguishable with respect to the electrical noise, on domestic power networks 400 of remarkable size, as well as on public networks on which the system may be installed, even in the presence of strong electromagnetic disturbances.
• optical radiation system for diffusing data comprising:
• an optical transmitting device operatively connected to the domestic power network 400 at the aforesaid second point by means of the inputs 99d thereof, and
• the device for injecting the data signal s(t) may advantageously be a particular embodiment of the optical transmitting device according to the invention, if equipped with an optical receiving stage.
• the inputs 99d due to the presence of the connection between the output 207 of the demodulator and the decoupling stage 216, also become terminals for the connection to the domestic power network 400, and advantageously allow to transform the aforesaid device into a means suitable for transmitting on the domestic power network 400 a data signal, in particular, a data signal received from another optical radiation.
• the Applicant has observed that such configuration is particularly advantageous if the domestic power network 400 is realised in the form of several subnets, which, although electrically connected to one another, are decoupled so that a data signal passing therethrough may not diffuse widely on all sub-networks. Equally, the Applicant has observed that such configuration is particularly advantageous if, with the system as described, connecting a plurality of electrically isolated power networks - from the point of view of data diffusion - is desired.
• the modulations and demodulations are of the hybrid type - therefore with AM and FM modulation cascade in transmission and FM and AM in reception, in accordance with the features previously exposed - the system becomes particularly adapted to transmit electronic data by means of optical radiation between two isolated power networks or electrical sub-networks, in environments in which no direct transmission of an optical radiation between a receiver and a transmitter is possible.
• the advantages of the device and of the method described herein are apparent in the light of the above description.
• the diffusion of data signals advantageously occurs without the use of radiation systems employing radio waves.
• the optical radiation 108 diffused by the photoemitter 100 is confined in a closed domestic environment, without the possibility of diffusion outside, it would not be possible for a fraudulent listener to receive and therefore to decode the data signal modulated through the radiation if not through a physical presence of a suitable receiving device directly in the environment where the optical radiation 108 is diffused.
• the suitability of the device object of the invention for transmitting multimedia data allows the use thereof as a device for the diffusion or streaming of audio/video streams, generated from sources available inside, or in any case close to, the environment where the device is placed or, alternatively or in combination thereof, remotely retrieved.
• the device object of the invention may be applied in environments where the atmosphere is at risk of explosion, since optical radiations, unlike non-ionizing radio frequency radiations, pose fewer risks of ignition of such atmosphere.

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• 2018
  • 2018-09-10 EP EP18782794.4A patent/EP3729689A1/de active Pending
  • 2018-09-10 WO PCT/IB2018/056872 patent/WO2019049090A1/en unknown

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