JP2018142945A - Method for using elliptically polarized light to concurrently perform multiplex communication of two signals by one electromagnetic wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform multiplex communication with one kind of electromagnetic waves in interplanetary communication, satellite communication or the like in a planetary probe, thereby shortening the time for transmission and reception of a large amount of signals, increasing the number of channels of satellite communication, decreasing the number of transponders of a planetary probe or artificial satellite and consequently decreasing the weight of the planetary probe or artificial satellite.SOLUTION: In the present invention, multiplex communication is performed in such a way that a pair of signals are concurrently transmitted and received by one electromagnetic wave and the signals are transmitted and received according to elliptical polarization instead of circular polarization that has been used for interplanetary communication and satellite communication. It makes possible: to shorten a communication time of interplanetary communication; to increase the number of channels of satellite communication; and to decrease the number of transponders of an artificial satellite. Using elliptical polarization, the transmission time and reception time in interplanetary communication can be both shortened to about 1/2. On a reception side in satellite communication, a pair of signal voltages are identified and separated by use of a ratio of a pair of voltages of a received elliptically polarized electromagnetic wave, and the pair of signals are each processed as a signal concerned. The polarization mode offers a technique which can be used in any of analog signal communication and digital signal communication. In elliptical polarization and circular polarization, an electromagnetic wave has a pair of electric fields of which the polarization planes are normal to each other and different by 90°. With elliptical polarization, simple harmonic vibrations of the pair of electric fields different in electric field amplitude are shifted from each other by a quarter of one vibration time temporally. Circular polarization has the same characteristics as those of elliptical polarization except that a pair of electric fields of an electromagnetic wave are identical to each other in simple harmonic vibration amplitude; simple harmonic vibrations of the pair of electric fields are shifted from each other by a quarter of one vibration time temporally. Because of the temporal difference of a quarter of one vibration time between the electric fields, the forefront (maximum amplitude point) of each electric field vector appears to rotate on an electromagnetic wave-receiving plane in terms of location. The electromagnetic wave has right-turning polarized and left-turning polarized electromagnetic wave components because of the pair of electric fields being in such a temporal relation that one electric field is precedent to the other; electric fields of the polarized electromagnetic wave components appear to change according to a circle on the receiving plane in circular polarization, and they appear to change according to an ellipse in elliptical polarization. When an artificial satellite radiating an elliptically polarized electromagnetic wave is rotating, the ellipse appears as if rotating, and the direction of each axis of the ellipse of the electric fields in the receiving plane is not fixed. In the case of using elliptical polarization for satellite communication with a planetary probe or artificial satellite, it will do the business to separate and identify transmitted signals by use of a ratio of voltages in major and minor axis directions of the ellipse in consideration of the attenuation of an electromagnetic wave in the atmosphere, the ionosphere and water vapor on condition that signals at a receiving point of a parabola antenna are used; the forefront of each electric field vector at the receiving point will move along the circumference of the ellipse with time. In a view of its physical phenomenon, the electromotive force caused by each electric field of an elliptically polarized electromagnetic wave at the receiving point of the parabola antenna changes with time. Electromotive forces caused by the electric fields in major and minor axis directions of the ellipse become maximum and minimum respectively. So, it will do the business to detect the electromotive forces at the receiving point at intervals of a signal-transmission time (the number of vibrations at the time of signal transmission) of the smallest unit of a digital or analog signal. The maximum and minimum voltages of the electromotive forces caused by the electric fields of elliptical polarization are detected by: amplifying signals of the minimum and maximum values of the electromotive forces to obtain a pair of signals from the amplified signals; directly detecting a peak voltage from one of the pair of signals; inverting the other signal by a transistor; and superposing a bias voltage of plus or minus polarity on the inverted other signal to detect a peak of the resultant voltage. Performing the above voltage detecting operation at intervals of the minimum unit time of signal transmission, a pair of signals transmitted from the planetary probe or artificial satellite can be concurrently separated and identified by one electromagnetic wave without performing time division in a way that follows the change of maximum and minimum voltages of the peak voltages according to time sequence even if the electromagnetic wave is subjected to FM-modulation. Since the maximum and minimum values of the electromotive forces are detected at intervals of the minimum unit time of signal transmission, the change in electromotive force attributed to the electromagnetic wave fading or the like is absorbed, and what are the pair of signals can be determined by e.g. an identification code that each transmitted signal includes. In addition, an advantage of the invention is that a pair of signals can be concurrently transmitted and received by elliptical polarization without performing time division of an electromagnetic wave of one frequency. If there is no need for concurrently transmitting and receiving a pair of signals, things would go well by transmitting and receiving one signal by one electric field in the same way as in conventional satellite communication by circular polarization. If the other electric field carries no signal, the peak voltage of electromotive force does not change with time on a reception side and as such, the electromagnetic wave can be handled as an electromagnetic wave with no signal. In an electromagnetic wave according to a conventional circularly polarization, electric fields making a pair are identical to each other in amplitude and in the change of peak voltages of electromotive forces caused by the pair of electric fields with time. So, the paired signals to be output are the same. In this case, it is assumed that "a circularly polarized electromagnetic wave has been received," and electromotive forces caused by a pair of electric fields are compared for voltage output in differential amplification. If a voltage of zero (0) is output as a result of the differential amplification, it will do the business to take only one voltage output, as a signal.

Description

  The present invention relates to the communication field.

  This invention is a method of using elliptically polarized light to simultaneously multiplex two signals with one electromagnetic wave in interplanetary communication or satellite communication of a planetary explorer, and simultaneously transmit and receive two signals with one electromagnetic wave. Can reduce the time to send and receive large amounts of signals, reduce the number of transponders for satellite communications, lighten planetary probes and artificial satellites, and conversely You can increase the number of channels.

  Until now, satellite communications of planetary probes and artificial satellites have an ionosphere in the thermosphere of the Earth's atmosphere, so unlike the linear polarization of electromagnetic waves for broadcasting on radio, VHF, and UHF television, Circularly polarized light is used for electromagnetic waves, and satellite broadcasting antennas need circular parabolic antennas, unlike flat Yagi antennas. However, since circularly polarized light is used for the polarization mode of electromagnetic waves for transmitting and receiving signals, only one signal can be transmitted and received at the same time by one electromagnetic wave, and it takes time to transmit and receive a large amount of signals.

  By using multiple communications with a single electromagnetic wave in interplanetary communications and satellite communications of planetary explorers, shortening the time for transmitting and receiving large amounts of signals and increasing the number of satellite communications channels, planetary probes and artificial satellites Reduce the number of transponders in the planet and lighten planetary probes and satellites.

  Therefore, in this invention, the circularly polarized light used in interplanetary communication and satellite communication is changed to elliptically polarized light, and signals are transmitted / received, and two signals are simultaneously transmitted / received by one electromagnetic wave. Therefore, the communication time of interplanetary communication is shortened, the number of satellite communication channels is increased, and the number of satellite transponders is decreased. By using elliptically polarized light, the transmission / reception time of interplanetary communication can be shortened to about 1/2, and the receiving side of satellite communication can receive two signals with two voltage ratios of the received elliptically polarized electromagnetic wave. Are separated and processed as signals. This polarization mode is a technology that can be used for both analog signal communication and digital signal communication.

  According to the present invention, the interplanetary communication time of the planetary explorer can be shortened to about ½, the number of satellite broadcast channels can be increased, the number of transponders can be reduced, Since the artificial satellite can be lightened or two signals can be transmitted and received simultaneously with one electromagnetic wave, it can be used for a spare satellite communication line.

Therefore, in this invention, the circularly polarized light used in interplanetary communication and satellite communication is changed to elliptically polarized light, and signals are transmitted / received, and two signals are simultaneously transmitted / received by one electromagnetic wave. Therefore, the communication time of interplanetary communication is shortened, the number of satellite communication channels is increased, and the number of satellite transponders is decreased. By using elliptically polarized light, the transmission / reception time of interplanetary communication can be shortened to about 1/2, and the receiving side of satellite communication can receive two signals with two voltage ratios of the received elliptically polarized electromagnetic wave. Are separated and processed as signals. This polarization mode is a technology that can be used for both analog signal communication and digital signal communication.
In the case of elliptically polarized light and circularly polarized light, the polarization planes of the two electric fields of electromagnetic waves are vertically shifted by 90 °. In elliptically polarized light, the single vibration of two electric fields with different magnitudes of the electric field amplitude is one vibration time in time It is shifted by ¼, the circularly polarized light has the same amplitude of the single vibration of the two electric fields, the other is the same as the elliptically polarized light, and the single vibration of the two electric fields is only ¼ of one vibration time in time. It is off. Since the electric field is shifted in time by 1/4 of one vibration time, the position of the tip of the electric field vector (maximum amplitude point) appears to rotate on the electromagnetic wave receiving surface, and the two electric fields There are right-polarized and left-polarized electromagnetic waves in temporal context, and the change in the electric field on the receiving surface of these polarized electromagnetic waves is circular for circularly polarized light and appears elliptical for elliptically polarized light. When an artificial satellite that emits elliptically polarized electromagnetic waves rotates, the ellipse appears to rotate, and the direction of the ellipse axis of the electric field on the receiving surface is not fixed.
When using elliptically polarized light for satellite communications with planetary probes or artificial satellites, considering the attenuation of electromagnetic waves in the atmosphere, ionosphere, and water vapor, when using the signal at the receiving point of the parabolic antenna, the vertical and horizontal directions of the ellipse It is only necessary to separate and identify the transmitted signal using the voltage ratio of the axis, and the tip of the electric field vector at the receiving point goes around the ellipse in time, and in terms of physical phenomena, The electromotive force due to the electric field of the elliptically polarized electromagnetic wave at the receiving point of the antenna changes with time, and the electromotive force due to the vertical and horizontal electric field axes of the ellipse is its maximum value and minimum value. Alternatively, the electromotive force at the reception point may be detected by the minimum signal transmission time of analog signals (the number of vibrations at the time of signal transmission). The maximum and minimum values of the electromotive force are separated into two amplified signals, one is detected as it is, the peak voltage is detected, and the other is inverted by a transistor to adjust the bias voltage. By detecting the peak voltage, the maximum and minimum voltages of the electromotive force due to the electric field of elliptically polarized light are detected. By performing this voltage detection operation at every signal transmission minimum unit time, even an electromagnetic wave that has been subjected to FM modulation is time-divided by one electromagnetic wave by following the voltage change between the maximum and minimum peak voltages in time series. It is possible to separate and distinguish two signals transmitted from planetary probes and satellites at the same time . By detecting the maximum value and minimum value of superpower in the minimum signal transmission unit time, the change in superpower due to fading of electromagnetic waves, etc. is absorbed, and the two signals are transmitted. It can be judged by the identification code included in the incoming signal.
An advantage of the present invention is that two signals can be transmitted and received simultaneously by elliptically polarized waves without time-dividing electromagnetic waves of one frequency. If it is not necessary to transmit and receive two signals simultaneously, As with conventional circularly polarized satellite communications, one signal can be transmitted and received with one electric field. If no signal is put on the other electric field, the receiving side can treat the peak voltage of the electromotive force as a non-signal electromagnetic wave because the voltage does not change with time.
The conventional circularly polarized electromagnetic waves have the same amplitude of the two electric fields and the same change in the temporal peak voltage of the electromotive force due to the two electric fields, so the two signals that are output are the same, In this case, “circularly polarized electromagnetic waves have been received”, the electromotive force due to the two electric fields is compared as an output voltage by operating amplification, and when the operating amplification output voltage is 0, only one voltage output is output. As a signal.

Claims (1)

  A method of multiplexing two signals simultaneously with one electromagnetic wave using elliptically polarized light