JP6644296B2 - Communication system and communication terminal using waveform selection filter - Google Patents

Description

The present invention is also applicable to radio waves in the same frequency band or in a band in which a plurality of frequencies are present, and the waveform of the radio wave (specifically, the length of the radio wave (pulse) in time units in which the radio wave is generated; Communication system and communication system that realizes waveform selectivity and time-domain control using a waveform selection filter (waveform selection metasurface) having electromagnetic characteristics that enable selective absorption and transmission according to pulse width) It is.

A conventional wireless multiple access method will be described with reference to FIG. 10A shows the FDMA system (frequency division multiple access system), FIG. 10B shows the TDMA system (time division multiple access system), and FIG. 10C shows the CDMA system (code division multiple access system). The FDMA scheme divides a communication signal of each user on the frequency axis (f) to realize multiplexing. The TDMA system multiplexes by dividing a communication signal of each user on a time axis (t). The CDMA system multiplexes a communication signal of each user by dividing the communication signal on a code axis (such as a spread code). Note that the three axes of the frequency axis (f), the time axis (t), and the code axis (such as a spread code) are orthogonal (independent), and any combination is possible. As an example of realizing this, there is an OFDMA system shown in FIG. In the OFDMA scheme, in the FDMA scheme using orthogonal subcarriers and the TDMA scheme, a communication signal of each user is divided to realize multiplexing.
In particular, a wide variety of research efforts have been made in wireless multiple access for a plurality of user wireless communications in the same frequency band. As described above, radio frequency resources are divided in the FDMA, TDMA, CDMA, and OFDMA schemes. It is multiplexing. As described above, research efforts to improve the use efficiency of frequency resources have been widely pursued in recent years, and the multiple access method has been put to practical use, including the cellular network of mobile phones. However, in a system using three axes of a frequency axis (f), a time axis (t), and a code axis (such as a spread code), the frequency utilization efficiency is theoretically limited.

In recent years, communication terminals such as mobile phones and smartphones, and wireless LANs and the like have exploded, and it has been pointed out that frequency resources have been depleted against the background of such expanded use of wireless communication. More user multiplexing scheme is required for frequency resource depletion

Non-Patent Document 1 discloses a metasurface that non-linearly absorbs a surface current (or surface wave) in order to protect a communication electronic device from a high power signal. Realistically, a high power signal is a radio wave having a short pulse width like an impulse. Therefore, the metasurface absorbs radio waves having a short pulse width and transmits long radio waves, and is attached to the outer periphery of the communication device to protect the communication device. Therefore, it is not used for communication itself.

H. Wakatsuchi, S. Kim, J. J. Rushton, D. Sievenpiper, “Waveform-Dependent Absorbing Metasurfaces”, Physical Review Letters 111, 245501, December 2013.

We propose a completely new wireless multiple access method using the new electromagnetic field characteristic "waveform (pulse width) selectivity" invented by the present inventors. This waveform width selectivity is a new electromagnetic field phenomenon that can change the electromagnetic field characteristics (transmission, absorption, etc.) not only by frequency but also by pulse length (signal excitation time). A "waveform axis" is added to a frequency, time, and code (FDMA, TDMA, and CDMA systems), which are division axes of the conventional multiple access, by a new wireless multiple access system to which this is applied. As a result, we aim to achieve frequency utilization efficiency that exceeds the limits of conventional communication theory and to dramatically expand depleting radio frequency resources.

The present invention introduces the concept of pulse width selectivity (waveform axis) to three axes of frequency, time, and code in a conventional communication system, and selects a waveform by a pulse width in the same frequency band or a band in which a plurality of frequencies exist. The present invention provides a multiplexed communication system and communication terminal using a waveform selection filter that performs the following.
Invention 1 includes a transmitting communication terminal that transmits a radio wave by controlling a pulse width that is an excitation time of a radio wave to a specific pulse width, and a receiving communication terminal that receives a radio wave transmitted by the transmitting communication terminal. The receiving communication terminal has a waveform selection filter and a reception unit, the waveform selection filter selectively transmits or reflects radio waves having a specific pulse width, and the reception unit includes a specific pulse transmitted by the waveform selection filter. It is a communication system that receives radio waves of a width.
In a second aspect, the waveform selection filter includes a conductive member, a rectifier circuit connecting two portions of the conductive member, and one or both of the RL circuit and the RC circuit, and the RL circuit is a circuit element having an inductive component. And a circuit element having a resistance component.The RC circuit has a circuit element having a capacitive component and a circuit element having a resistance component.The waveform selection filter absorbs a radio wave by a pulse width which is an excitation time of the radio wave. It is characterized by different rates.
In a third aspect, the transmission-side communication terminal includes a pulse time waveform controller that controls a pulse width of a radio wave to a specific pulse width, and a transmission-side frequency converter that performs multiplexing in a frequency domain. The radio wave transmitted by the communication terminal is controlled to a specific pulse width by the pulse time waveform controller, and multiplexed in the frequency domain by the transmission-side frequency converter. It has a receiving-side frequency converter for selectively receiving a signal in a specific frequency region among radio waves of a specific pulse width transmitted by the selection filter.
In a fourth aspect, the transmission-side communication terminal includes a pulse time waveform controller for controlling the pulse width of the radio wave to a specific pulse width, and a transmission-side access time controller for performing multiplexing with access time. The radio wave transmitted by the side communication terminal is controlled to a specific pulse width by the pulse time waveform controller, and is multiplexed by the access time by the transmission side access time controller. And a receiving-side access time controller for selectively receiving a signal of a specific access time among radio waves of a specific pulse width transmitted through the waveform selection filter.
In a fifth aspect, the transmission-side communication terminal includes a pulse time waveform controller that controls a pulse width of a radio wave to a specific pulse width, and a code spreader that performs multiplexing in a spread code area. The radio wave transmitted by the terminal is controlled to a specific pulse width by a pulse time waveform controller, and is multiplexed in a spread code region by a code spreader. Is characterized by having a code despreader for selectively receiving a signal that has been signal-spread with a specific spreading code among radio waves of a specific pulse width transmitted therethrough.
Invention 6 is a receiving communication terminal that receives a radio wave from a transmitting communication terminal that transmits a radio wave by controlling a pulse width, which is an excitation time of a radio wave, to a specific pulse width. The waveform selection filter selectively transmits radio waves having a specific pulse width, and the reception unit is a receiving communication terminal that receives radio waves having a specific pulse width transmitted by the waveform selection filter.
Invention 7 is characterized by including a pulse time waveform controller for controlling a pulse width which is an excitation time of a radio wave to be transmitted.
Invention 8 is a transmitting-side communication terminal that transmits a radio wave to a receiving-side communication terminal that selectively receives a radio wave whose pulse width, which is the excitation time of the radio wave, has a specific pulse width. This is a transmission-side communication terminal that transmits a radio wave by controlling the pulse width to a specific pulse width.

According to the first aspect, a transmitting communication terminal that transmits a radio wave by controlling a pulse width that is an excitation time of a radio wave to a specific pulse width, a receiving communication terminal that receives a radio wave transmitted by the transmitting communication terminal, The reception side communication terminal has a waveform selection filter and a reception unit, the waveform selection filter selectively transmits or reflects a radio wave having a specific pulse width, and the reception unit determines a specific radio wave transmitted by the waveform selection filter. A multiplexed communication system that receives radio waves having a pulse width of That is, the receiving side selectively receives a specific pulse width.
According to the second aspect, the specific configuration of the waveform selection filter is specified.
According to the third aspect, in the communication system of the FDMA system which is frequency division, a frequency converter and a pulse time waveform controller are installed on the transmission side, and a waveform selection filter and a frequency converter are installed on the reception side. A multiplexed communication system based on waveform selection can be provided.
According to the fourth aspect of the present invention, in a TDMA communication system that is a time division method, an access time controller and a pulse time waveform controller are installed on the transmission side, and a waveform selection filter and an access time controller are installed on the reception side, thereby providing a pulse. It is possible to provide a multiplexed communication system by selecting a waveform by width.
According to the fifth aspect, in a CDMA communication system using code division, a code spreading and pulse time waveform controller is installed on the transmitting side, a waveform selection filter and a code despreading are installed on the receiving side, thereby enabling waveform selection by pulse width. Can provide a multiplexed communication system.
According to the sixth aspect, it is possible to provide a receiving communication terminal equipped with a waveform selection filter.
According to the seventh aspect, a receiving-side communication terminal having both a transmitting function and a receiving function can be provided.
According to the eighth aspect, it is possible to provide a transmitting communication terminal that transmits a radio wave by controlling the pulse width of the radio wave to a specific pulse width.
As described above, with the communication system and the communication terminal of the present invention, it is possible to realize frequency utilization efficiency exceeding the limit of the conventional communication theory and to dramatically expand depleting radio frequency resources.

(A) The effect of the waveform selection filter 20 is schematically shown. (B) The structure of the waveform selection filter 20 is schematically shown. 4 shows schematic structural diagrams of four types of the waveform selection filter 20. FIG. The four types of characteristics of the waveform selection filter 20 are shown. The simulation evaluation model and evaluation environment are shown. The characteristic evaluation (same frequency) by the pulse modulation method is shown. 1 schematically shows a configuration of a communication system 1 that performs multiplexing by waveform selectivity using the same frequency band or a band in which a plurality of frequencies exist. An example of multiplexing by FDMA and waveform selectivity using the same frequency band or a band in which a plurality of frequencies exist is shown schematically showing a configuration of a communication system 1 that performs multiplexing by waveform selectivity. An example in which a pulse time waveform controller 10 and a waveform selection filter 20 are mounted on a communication terminal 2 is shown. An example of an assumed use (example of a wireless LAN network) of the multiple access method by the waveform selection filter 20 is shown. 1 shows a conventional wireless multiple access method. Pulse modulation method (same frequency) Simulation result of the characteristics of the waveform selection filter (same frequency) Time domain control principle by OFDM Time domain control principle by OFDM (multiple frequencies) Simulation result of characteristics of waveform selection filter (multiple frequencies) Multiplexing method using waveform selection filter (transmitting side) Multiplexing method using waveform selection filter (receiving side) A method that introduces FDMA for multiplexing with a waveform selection filter (transmitting side) A method that introduces FDMA for multiplexing with a waveform selection filter (receiving side) A method that introduces FDMA and TDMA for multiplexing by a waveform selection filter (transmitting side) A method that introduces FDMA and TDMA for multiplexing by a waveform selection filter (receiving side) Method that introduced CDMA for multiplexing by waveform selection filter (transmitting side) A method that introduces CDMA to multiplexing by a waveform selection filter (transmitting side, another form) A method that introduces CDMA to multiplexing by a waveform selection filter (receiving side) Evaluation of multiplexing by waveform selection filter (communication channel capacity) Evaluation of multiplexing by waveform selection filter (number of users)

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be made without departing from the scope of the invention.

FIG. 1A schematically shows the effect of the waveform selection metasurface 20 (hereinafter, referred to as a waveform selection filter 20).
The radio waves shown on the left side of FIG. 1A are radio waves on the input side to the waveform selection filter 20, and have the same frequency but different pulse widths. Here, as shown in FIG. 1, the pulse width is the length of a radio wave (pulse) in time units in which the radio wave is generated. The pulse width is also the length of time during which the energy of the radio wave is generated (radiation excitation time).
In the center of FIG. 1 (a), even radio waves of the same frequency are selectively selected according to the waveform of the radio waves (specifically, the length of the radio waves (pulses) in time units in which the radio waves are generated). Is a waveform selection filter 20 having an electromagnetic characteristic that allows absorption and transmission. Here, a short-wave absorption waveform selection filter 22 that absorbs radio waves having a short pulse width and transmits radio waves having a long pulse width is shown.
The radio wave shown on the right side of FIG. 1A indicates that a radio wave having a short pulse width is absorbed and a radio wave having a long pulse width is transmitted.
FIG. 1B schematically shows the structure of the waveform selection filter 20. A dielectric 26 is provided on the metal plate 27, and has a basic basic shape in which a plurality of conductive members 25 are disposed on the dielectric 26. It is based on a two-dimensional plane. Also, by making the curvatures of the metal plate 27, the dielectric 26, and the conductive member 25 laminated on the same portion the same, the waveform selection filter 20 as a whole has a semi-cylindrical, hemispherical, conical, or It can be formed into a three-dimensional shape based on a parabolic antenna. Here, when the metal plate 27 is provided as described above, it is a reflection type, while the waveform selection filter 20 in which the metal plate 27 is abolished is a transmission type. The waveform selection filter 20 may be a transmission type or a reflection type.

2 and 3 are schematic structural diagrams and characteristics of four types of the waveform selection filter 20. FIG.
FIG. 2A is a schematic structural diagram of the capacitor-type waveform selection filter 22 (absorbing a radio wave with a short pass width) that absorbs a radio wave with a short pulse width and transmits a radio wave with a long pulse width, and FIG. Show.
FIG. 2A has a rectifier circuit that connects two portions of the conductive member 25 (that is, the left conductive member 25 and the right conductive member 25), and an RC circuit disposed in the rectifier circuit. The current rectified by the rectifier circuit flows through the RC circuit. This RC circuit has a circuit element C having a capacitive component and a circuit element Rc having a resistance component. The circuit element C and the circuit element Rc are connected in parallel.
Here, the saturation pulse width of the absorption curve in FIG. 3B is determined by the time constant τ (τ = R _c C) of the circuit element used.
FIG. 2 (b) is a schematic structural diagram and FIG. 3 (b) is a schematic structural diagram of an inductor type waveform selection filter 21 (absorbing a radio wave having a long pass width) that absorbs a radio wave having a long pulse width and transmits a radio wave having a short pulse width. Show.
FIG. 2B has a rectifier circuit that connects two portions of the conductive member 25 and an RL circuit disposed in the rectifier circuit. The current rectified by the rectifier circuit flows through the RL circuit. This RL circuit has a circuit element L having an inductive component and a circuit element Rl having a resistance component. The circuit element L and the circuit element Rl are connected in series.
Here, the saturation pulse width of the absorption curve in FIG. 3B is determined by the time constant τ (τ = L / R _l ) of the circuit element used.
Next, FIG. 2C shows a schematic structural diagram of the parallel-coupling type waveform selection filter 23, and FIG. 3C shows characteristics thereof. It has a concave absorption characteristic that absorbs radio waves with a short pulse width and radio waves with a long pulse width and transmits radio waves with a pulse width located in the middle.
FIG. 2C shows a rectifier circuit that connects two portions of the conductive member 25, and an RL circuit and an RC circuit connected in parallel within the rectifier circuit. A current rectified by the rectifier circuit flows through the RL circuit and the RC circuit. The RL circuit has a circuit element L having an inductive component and a circuit element Rl having a resistance component in series. The RC circuit has a circuit element C having a capacitive component and a circuit element Rc having a resistance component in parallel.
Here, the absorption curves in FIG. 3 (c) are the time constants τ (L / R _{l) of the} circuit elements used in the independent radio wave absorption waveform selection filter having a long pulse width and the radio wave absorption waveform selection filter having a short pulse width, respectively. , R _c C).
Next, FIG. 2D shows a schematic structural diagram of the series-coupled waveform selection filter 24, and FIG. 3D shows its characteristics. This has a convex absorption characteristic of transmitting a radio wave with a short pulse width and a radio wave with a long pulse width and absorbing a radio wave with a pulse width positioned between them.
FIG. 2D includes a rectifier circuit that connects two portions of the conductive member 25, and an RL circuit and an RC circuit connected in series within the rectifier circuit. A current rectified by the rectifier circuit flows through the RL circuit and the RC circuit. The RL circuit has a circuit element L having an inductive component and a circuit element Rl having a resistance component in series. The RC circuit has a circuit element C having a capacitive component and a circuit element Rc having a resistance component in parallel.
Here, the absorption curves in FIG. 3 (d) are time constants τ (L / R _{l) of the} circuit elements used for the independent radio wave collection waveform selection filter having a long pulse width and the radio wave absorption waveform selection filter having a short pulse width, respectively. , R _c C).
As described above, the waveform selection filter includes the conductive member 25, the rectifier circuit connecting the two portions of the conductive member 25, and the circuit element L having an inductive component and the circuit element R having a resistance component in the rectifier circuit. An RL circuit, or an RC circuit including a circuit element C having a capacitive component and a circuit element R having a resistance component, or an RL circuit and an RC circuit. .
Note that the circuit element R having a resistance component does not necessarily need to be a resistor, and may be replaced by a MOSFET or the like. Further, the circuit element C having a capacitive component does not necessarily need to be a capacitor, and can be replaced with a varactor diode.

FIG. 4A shows a simulation evaluation model, in which a radio signal output from a transmitter propagates on a filter and is input to a receiver.
The signal waveform in the upper part of FIG. 4B shows the signal input to the receiver antenna 31 at the position of “★ 1” in FIG. 4A, which is absorbed by the filter and corresponds to the pulse width. Absorption is realized.
The signal waveform at the bottom of FIG. 4B shows the signal at the position of “★ 2” in FIG. 4A, and the signal input from the receiver antenna 31 is amplified by an amplifier. , Thermal noise (Gaussian noise) is added, and this is shown.
FIG. 4C shows an environment for simulation evaluation. The simulation environment is roughly divided into three parts: a transmission unit 51, a channel unit 52, and a reception unit 53. The transmission unit 51 performs signal modulation based on the transmission bit sequence and generates a modulated wireless signal. In this simulation, pulse position modulation (PPM), which is one of simple narrow-band pulse modulations, is employed. In PPM, the bit information is a modulation method represented by the temporal position of the first half or the second half of the pulse. Note that the pulse generation unit 511 also performs time domain signal processing for shaping the pulse width in addition to generating the carrier signal in order to confirm the effect of the waveform selection filter used in the present invention.
Next, the channel unit 52 simulates the effect of the transmitted radio signal on the radio channel. The transmitted radio signal is first absorbed by the waveform selection filter 20, but in this simulation, the absorption effect of the waveform selection filter 20 is calculated in advance by electromagnetic field simulation, and the data is used. As a noise source, additive white Gaussian noise (AWGN) is assumed, and after being absorbed by the waveform selection filter 20, AWGN is added.
Finally, demodulation is performed after detection is performed in the receiving unit 53, and the bit error rate is calculated. In this simulation, energy detection is adopted as the detection method. The receiving unit 53 first calculates two energy values corresponding to the pulse positions from the received signal, and these two output energy values are sequentially input to the comparator 531. The symbol timing obtained by the symbol timing unit 532 is input to the comparator 531, and the comparator 531 compares the two energy values input at appropriate timings to determine a received bit.

FIG. 5 shows characteristics evaluation by the pulse modulation method.
Basic evaluation of multiplexing based on waveform (pulse width) selectivity using the waveform (pulse width) selection filter 20 invented by the present inventors was performed.
The graphs of FIGS. 5A and 5B show Eb / N0 on the horizontal axis, which is the ratio of the spectral density of the transmission signal energy Eb to the noise energy N0. It shows that the energy Eb of the transmission signal increases as Eb / N0 increases as compared with the noise energy N0.
In the graphs of FIG. 5A and FIG. 5B, the vertical axis indicates a bit error rate characteristic (BER: Bit error rate), and at what rate a bit error (error) occurs in digital transmission. To indicate For example, BER = 0.01 indicates that an error has occurred on average for one bit out of 100 bits, and it can be said that the smaller the BER, the higher the quality of the communication.
Here, the reference is the characteristic (W / O SUT) without the waveform selection filter 20 indicated by “X”. If the characteristic using the waveform selection filter 20 is equal to the characteristic indicated by "X", the communication is of the same quality. The evaluated pulse widths are three levels, and the pulse width is 0.02 μs for “black square”, 2 μs for “black circle”, and 20 μs for “black triangle” in ascending order of pulse width.
FIG. 5A shows communication characteristics when a capacitor-type waveform selection filter 22 (FIGS. 2A and 3A) that absorbs short pulses and transmits long pulses is used. The BER characteristic of a pulse width of 0.02 us indicated by “black square” is greatly deteriorated from the characteristic (W / O SUT) indicated by “X”, which is a reference, without the capacitor type waveform selection filter 22. That is, a radio wave having a short pulse width (0.02 us) is selectively absorbed by the capacitor type waveform selection filter 22.
On the other hand, the characteristics of the BER having a pulse width of 2 us indicated by "black circles" and a pulse width of 20 us indicated by "black triangles" are almost the same as the characteristics (W / O SUT) without the capacitor type waveform selection filter 22 indicated by "X". Same and no deterioration of characteristics. That is, a radio wave having a pulse width of 2 us indicated by a "black circle" or a pulse width of 20 us indicated by a "black triangle" can be obtained by using a capacitor type waveform selection filter 22 that absorbs short pulses and transmits long pulses. The characteristics are equivalent to those when the selection filter 22 is not used.
For this reason, according to the present embodiment, the waveform selection filter allows a signal having a long pulse width to pass therethrough without significant deterioration, and blocks a signal having a short pulse width.
FIG. 5B shows a communication using the inductor-type waveform selection filter 21 (FIGS. 2B and 3B) that absorbs radio waves having a long pulse width and transmits radio waves having a short pulse width. Show characteristics. The characteristic (W / O SUT) without the inductor type waveform selection filter 21 is indicated by “X”. The characteristics of the BER having a pulse width of 2 us indicated by "black circles" and a pulse width of 20 us indicated by "black triangles" are significantly deteriorated from the characteristics (W / O SUT) without the inductor type waveform selection filter 21 indicated by [X]. ing. On the other hand, the BER characteristic of the pulse width of 0.02 us indicated by “black square” is almost the same as the characteristic (W / O SUT) without the inductor type waveform selection filter 21 indicated by [X], and is not deteriorated. . That is, a radio wave having a pulse width of 0.02 us indicated by a “black square” is obtained when the inductor-type waveform selection filter 21 that absorbs a long pulse and transmits a short pulse is used, but the inductor-type waveform selection filter 21 is not used. The characteristics are almost the same. For this reason, according to the present embodiment, the inductor-type waveform selection filter 21 allows a signal having a short pulse width to pass therethrough without significant deterioration, and blocks a signal having a long pulse width. Therefore, by adjusting the inductor-type waveform selection filter 21, it is possible to achieve a characteristic opposite to that of FIG.
Considering the results of FIGS. 5 (a) and 5 (b) comprehensively, it is fundamental to set an appropriate pulse width for each user and transmit only signals of arbitrary users (user multiplexing). It became clear from a simulation study.

FIG. 11 shows a configuration example of a method (single frequency) using the pulse modulation method. The bit sequence generator generates a bit sequence to be transmitted, and the output sequence is input to a PPM (Pulse Position Modulation) modulator. In the PPM modulator, modulation is performed using a temporal position of a pulse corresponding to bit information, and a modulated signal is generated. Note that in the original PPM modulation, the modulation is realized by using the carrier signal (sine wave signal) as it is, but in the PPM modulation in FIG. The excitation time is controlled by the control unit 10 so as to have a pulse width corresponding to the absorption characteristic of the waveform selection filter 20, and PPM modulation using the output result is performed. The modulated signal is transmitted to a receiving side through a wireless communication path. On the receiving side, the signal is first passed through the waveform selection filter 20, and then received through a front-end processing part of wireless communication, such as an amplifier or a band-pass filter, which is a front end. The received signal detector detects (demodulates) the received signal from the front end output signal and outputs a received bit sequence. In FIG. 11, the front end and the received signal detector correspond to a receiving unit.

FIG. 12 shows a simulation result (for a single frequency). The horizontal axis indicates E _b / N ₀ , and the vertical axis indicates bit error rate characteristics (BER characteristics). The result of FIG. 12 indicates that the result has the same tendency as the result of FIG. 5 described above.
That is, FIGS. 5A and 12A show the case of the capacitor-type waveform selection filter 22 that absorbs radio waves with a short pulse width, and FIGS. 5B and 12B show the case of the long pulse width. This is the case of the inductor type waveform selection filter 21 that absorbs radio waves.
FIG. 12C shows the case of the parallel-coupling-type waveform selection filter 23 having a concave absorption characteristic. With respect to the BER characteristic (W / O SUT) without the parallel-coupling type waveform selection filter 23 shown by [X], the pulse width 2 us shown by "black circle" is hardly degraded, but by "black triangle" The pulse width of 20 us shown and the pulse width of 0.02 us shown as "black square" are significantly deteriorated. That is, a radio wave (0.02 us) having a small pulse width and a radio wave (20 us) having a large pulse width are absorbed, and a radio wave (2 us) having a pulse width therebetween is transmitted.
FIG. 12D shows a case of a series-coupled waveform selection filter 24 having a convex absorption characteristic. With respect to the BER characteristic (W / O SUT) without the series combination type waveform selection filter 24 shown by [X], the pulse width of 20 us indicated by [black triangle] and the pulse width of 0.02 us indicated by "black square" are as follows. Although there is almost no deterioration, the pulse width 2 us indicated by the “black circle” is largely deteriorated. That is, a radio wave (0.02 us) having a small pulse width and a radio wave (20 us) having a large pulse width are transmitted, and a radio wave (2 us) having a pulse width therebetween is absorbed.

FIG. 13 shows a configuration example of a method (a plurality of frequencies) based on OFDM (Orthogonal Frequency Division Multiplexing). The transmission bit data undergoes serial / parallel conversion by S / P, and is input in parallel to a QPSK modulator (four-phase shift keying modulator). Thereafter, the frequency domain signal is converted into a time domain signal by an IFFT unit (inverse Fourier transformer), and a guard interval is added by a GI unit. In the D / A, the generated digital signal is converted into an analog signal, and the pulse width is appropriately controlled by adjusting the subcarrier with a subcarrier mapper.
As one specific embodiment, since the frequency interval and the pulse width of the subcarrier have inverse characteristics, the pulse width can be arbitrarily set by controlling the frequency interval of the subcarrier. The subcarrier demapper on the receiving side performs the reverse operation to control the frequency interval of the subcarrier so as to correspond to an arbitrary pulse width.
The signal oscillated by the LO (local oscillator) is converted into a bandpass signal, and the frequency band is adjusted by a band pass filter (BPF) to generate a transmission signal. The transmission signal passes through a wireless communication path in the same manner as a single frequency, and is input to a reception unit after passing through a waveform selection filter. The receiving unit is realized by sequentially performing the processing of the transmitting unit in reverse order.

FIG. 14 shows the principle of pulse time waveform control in the OFDM method shown in FIG. FIG. 14 shows that the pulse width T of the time domain waveform of the OFDM signal is determined by the reciprocal of the subcarrier interval Δf. The subcarrier mapper in FIG. 13 controls the pulse width of the OFDM signal generated by adjusting Δf, and generates an OFDM signal having a pulse width suitable for the waveform selection filter. This is intended for radio waves having a pulse width in a band in which a plurality of frequencies exist.

FIG. 15 shows a simulation result (a band in which a plurality of frequencies exist). The horizontal axis indicates E _b / N ₀ , and the vertical axis indicates bit error rate characteristics (BER characteristics). The result of FIG. 15 shows that the result has the same tendency as the results of FIGS. 5 and 12 described above.
That is, FIG. 15A shows the case of the capacitor type waveform selection filter 22 that absorbs radio waves having a short pulse width. With respect to the BER characteristic (W / O SUT) without the capacitor type waveform selection filter 22 indicated by [X], the pulse width 20 us indicated by the “upper black triangle” has hardly deteriorated. On the other hand, the pulse width 1 us indicated by “lower black triangle”, the pulse width 500 ns indicated by “black circle”, and the pulse width 10 ns indicated by “black square” are significantly deteriorated. That is, a radio wave with a short pulse width (1 us, 500 ns, 10 ns) is absorbed, and a radio wave with a long pulse width (20 us) is transmitted.
FIG. 15B shows the case of the inductor-type waveform selection filter 21 that absorbs radio waves having a long pulse width. With respect to the BER characteristic (W / O SUT) without the inductor type waveform selection filter 21 shown by [X], the pulse width 10 ns shown by "black square" has hardly deteriorated. On the other hand, the pulse width 20 μs indicated by the “upper black triangle”, the pulse width 1 μs indicated by the “lower black triangle”, and the pulse width 500 ns indicated by the “black circle” are significantly deteriorated. That is, it transmits radio waves with a short pulse width (10 ns) and absorbs radio waves with a long pulse width (1 us, 500 ns, 20 us).
FIG. 15C shows a case of the parallel-coupling-type waveform selection filter 23 having a concave absorption characteristic. With respect to the BER characteristics (W / O SUT) without the parallel-coupling-type waveform selection filter 23 shown by [X], the pulse width 1 us indicated by “lower black triangle” and the pulse width 500 ns indicated by “black circle” are almost the same. Although not deteriorated, the pulse width 1 ns indicated by “black square” and the pulse width 20 uss indicated by “upper black triangle” are significantly deteriorated. That is, it absorbs a radio wave with a small pulse width (10 ns) and a radio wave with a large pulse width (20 μs), and transmits a radio wave with a pulse width between them (1 μs and 500 ns).
FIG. 15D shows the case of a series-coupling type waveform selection filter 24 having a convex absorption characteristic. With respect to the BER characteristic (W / O SUT) without the series combination type waveform selection filter 24 shown by [X], the pulse width of 20 us indicated by [black triangle] and the pulse width of 0.02 us indicated by "black square" are as follows. Although there is almost no deterioration, the pulse width 2 us indicated by the “black circle” is largely deteriorated. That is, a radio wave with a small pulse width (10 ns) and a radio wave with a large pulse width (20 us) are transmitted, and a radio wave with a pulse width between them (1 us, 500 ns) is absorbed.
As described above, the waveform selection filter 20 can selectively absorb and transmit radio waves having a pulse width in a band in which a plurality of frequencies exist, according to the pulse width.

(1st Embodiment)
FIG. 16 shows a multiplexing method (transmission side) using the waveform selection filter according to the first embodiment.
The transmitting communication terminal 2 has a pulse time waveform controller 10 following the modulator 12. The bit information input by the communication terminal is modulated by the modulator 12. The generated modulated signal is subsequently input to the pulse time waveform controller 10, which performs waveform control in a time domain that is transformed into a radio wave having a unique pulse width assigned to each transmitter / receiver pair. Thereafter, the radio wave is transmitted to the multiple access communication path 30.

FIG. 17 shows a multiplexing method (reception side) using a waveform selection filter according to the first embodiment.
It is assumed that the receiving communication terminal 2 receives the radio wave transmitted through the multiple access communication channel 30 by the waveform selection filter 20. The waveform selection filter 20 transmits radio waves with a specific pulse width and absorbs other radio waves. Therefore, only the radio wave of the specific pulse width assigned to the sender and the receiver by the waveform selection filter 20 is transmitted, and the radio wave of a specific pulse width is selectively received by the antenna 6. Thereafter, the received radio wave is input to the demodulator 16 and demodulated to obtain received bit information for a specific sender. In FIG. 17, the demodulator 16 corresponds to a receiving unit.

FIG. 6 schematically shows a configuration of a communication system 1 that performs multiplexing by a waveform selection filter in the same frequency band or a band in which a plurality of frequencies exist. In this communication system 1, a unique pulse width is assigned to each of N pairs of a transmitter and a receiver (hereinafter, “transmitter / receiver”), so that a radio channel of the same frequency band or a band in which a plurality of frequencies exist is assigned. Multiplexing is realized. Taking a pair of a sender # 1 and a receiver # 1 as an example, the sender # 1 communicates with the receiver # 1 by a radio wave having a specific specific pulse width. Similarly, the senders # 1, 2, 3,..., N are communicating with the receivers # 1, 2, 3,.
The transmitting communication terminal includes a modulator 12, a pulse time waveform controller 10, and then an antenna 6. The bit information input by the communication terminal is modulated by the modulator 12. The generated modulated signal is subsequently input to the pulse time waveform controller 10, which performs waveform control in a time domain that is transformed into a radio wave having a unique pulse width assigned to each transmitter / receiver pair. Thereafter, the radio wave is transmitted to the multiple access communication path 30 by the antenna 6.
The multiple access communication path 30 is a normal wireless communication space (wireless communication path), and is multiplexed by a plurality of radio waves.
It is assumed that the receiving communication terminal first receives the radio wave transmitted through the multiple access communication path 30 with the antenna 6 having the waveform selection filter 20. The waveform selection filter 20 transmits radio waves with a specific pulse width and absorbs other radio waves. Therefore, only the radio wave of the specific pulse width assigned to the sender and the receiver by the waveform selection filter 20 is transmitted, and the radio wave of a specific pulse width is selectively received by the antenna 6. Thereafter, the received radio wave is input to the demodulator 16 and demodulated to obtain received bit information for a specific sender. In FIG. 6, the antenna 6 and the demodulator 16 correspond to a receiving unit.
Here, the pulse time waveform controller 10 is configured to control the pulse width of the modulated signal output from the pulse modulator 12, and has a function of controlling the waveform in the time domain. As for the definition of the pulse time, in the case of a signal of a single frequency (sine wave signal), “excitation time of sine wave signal” is defined as “pulse width”. Therefore, it can be realized by a simple control mechanism of the pulse width, and the pulse time waveform controller can be constituted by a switch or a simple digital circuit element. On the other hand, the pulse width of a signal having a certain frequency bandwidth (a signal expressed by a combination of a plurality of sine-wave signals) is also defined by the "duration in which the signal exists at a certain signal strength or more". . The simple modulation method can be realized by a control mechanism using a switch or a simple digital circuit element, but it is difficult to realize the OFDM modulation described later using a simple mechanism such as a switch.
As described above, according to the first embodiment, in the conventional communication system, the same frequency band or a plurality of frequencies exist by installing the pulse time waveform controller 10 on the transmission side and the waveform selection filter 20 on the transmission side. The multiplexed communication system 1 can be provided by selecting a waveform in a band by a pulse width.

(2nd Embodiment)
FIG. 18 shows a method (transmission side) in which frequency division multiple access (FDMA) is introduced into multiplexing by a waveform selection filter.
The transmission-side communication terminal 2 has a frequency converter 14 (transmission-side frequency converter) subsequent to the modulator 12, and a pulse time waveform controller 10 subsequently.
The bit information input by the communication terminal 2 is modulated by the modulator 12 and subsequently converted into a signal on the assigned frequency band by the frequency converter 14. Subsequently, the pulse time waveform controller 10 converts the signal into a radio wave having a specific assigned pulse width. The generated radio wave is transmitted to the multiple access communication path 30.
Here, the frequency converter 14 performs multiplexing in the frequency domain by frequency division multiple access (FDMA). In addition, the pulse time waveform controller 10 performs multiplexing by selecting a waveform based on a pulse width.

FIG. 19 shows a system (receiving side) in which FDMA is introduced into multiplexing by a waveform selection filter.
The receiving communication terminal 2 first receives the radio wave transmitted through the multiple access communication path 30 by the waveform selection filter 20. In the waveform selection filter 20, a radio wave having a specific pulse width assigned to each transmission / reception pair is transmitted, and other radio waves are absorbed. This part realizes the selective reception of the radio wave of the assigned pulse width. In FIG. 19, the frequency converter 14 and the demodulator 16 correspond to a receiving unit.

FIG. 7 schematically shows a configuration example of a communication system 1 in which a multiplexing method in the frequency domain by frequency division multiple access (FDMA) and a multiplexing method by waveform selection are combined. In this configuration example, two-dimensional multiplexing is realized for the N pairs of transmitters and receivers in the frequency domain and the pulse width domain. Taking a pair of the sender # 1 and the receiver # 1 as an example, the sender # 1 is assigned a specific frequency band and a specific pulse width and communicates with the sender # 1. Similarly, the senders # 1, 2, 3,..., N perform communication by assigning specific frequency bands and pulse widths to the receivers # 1, 2, 3,.
The transmitting communication terminal 2 includes a modulator 12, a frequency converter 14 (receiving frequency converter), a pulse time waveform controller 10, and then an antenna 6.
The bit information is modulated by the modulator 12 and subsequently converted into a signal on the allocated frequency band by the frequency converter 14. Subsequently, the pulse time waveform controller 10 converts the signal into a radio wave having a specific assigned pulse width. The generated radio wave is transmitted to the multiple access channel 30 by the antenna 6.
Here, the frequency converter 14 performs multiplexing in the frequency domain by frequency division multiple access (FDMA). In addition, the pulse time waveform controller 10 performs multiplexing by selecting a waveform based on a pulse width.
The multiple access communication path 30 is a normal wireless communication space, and is a channel to which a plurality of wireless radio waves access in a multiplex manner.
It is assumed that the receiving communication terminal first receives the radio wave transmitted through the multiple access communication path 30 with the antenna 6 having the waveform selection filter 20. In the waveform selection filter 20, a radio wave having a specific pulse width assigned to each transmission / reception pair is transmitted, and other radio waves are absorbed. This part realizes the selective reception of the radio wave of the assigned pulse width. Further, the signal received by the antenna 6 is subjected to conversion for selectively receiving only a specific frequency region in the frequency converter 14. Only the radio signal selectively extracted in the frequency domain and the pulse width domain is input to the demodulator 16, and received bit information for a specific sender is output. In FIG. 7, the antenna 6, the frequency converter 14, and the demodulator 16 correspond to a receiving unit.
As described above, according to the second embodiment, in the conventional communication system of the FDMA system (frequency division multiple access system), by installing the pulse time waveform controller 10 on the transmission side and the waveform selection filter 20 on the transmission side, The multiplexed communication system 1 can be provided by selecting a waveform based on a pulse width in the same frequency band or a band in which a plurality of frequencies exist.

(Third embodiment)
FIG. 20 shows a configuration example of a system (transmission side) in which TDMA is introduced into multiplexing by a waveform selection filter.
The transmission-side communication terminal 2 includes an access time controller 17 (a transmission-side access time controller, followed by a pulse time waveform controller 10) following the modulator 12.
The bit information input by the communication terminal 2 is modulated by the modulator 12, and then converted into a signal on the assigned frequency band by the access time controller 17. Subsequently, the pulse time waveform controller 10 converts the signal into a radio wave having a specific assigned pulse width. The generated radio wave is transmitted to the multiple access communication path 30.
Here, the access time controller 17 performs multiplexing with access time by time division multiple access (TDMA). In addition, the pulse time waveform controller 10 realizes multiplexing by selecting a waveform based on a pulse width.

FIG. 21 shows a configuration example of a system (receiving side) in which TDMA is introduced into multiplexing by a waveform selection filter.
The receiving communication terminal 2 first receives the radio wave transmitted through the multiple access communication path 30 by the waveform selection filter 20. In the waveform selection filter 20, a radio wave having a specific pulse width assigned to each transmission / reception pair is transmitted, and other radio waves are absorbed. This part realizes the selective reception of the radio wave of the assigned pulse width.
Subsequently, the access time controller 17 (reception side access time controller) extracts a signal of a specific access time corresponding to each user.
Subsequently, the demodulator 16 demodulates the received signal and outputs a received bit sequence. In FIG. 21, the access time controller 17 and the demodulator 16 correspond to a receiving unit.

(Fourth embodiment)
FIG. 22 shows a configuration example of a system (transmission side) in which CDMA (code division multiple access system) is introduced into multiplexing by a waveform selection filter.
The transmitting communication terminal 2 includes a modulator 12, a code spreader 18, and a pulse time waveform controller 10 subsequently.
The bit information input by the communication terminal 2 is modulated by the modulator 12, and subsequently the signal is spread by the code spreader 18 using a spreading code corresponding to each user. Subsequently, the pulse time waveform controller 10 converts the signal into a radio wave having a specific assigned pulse width. The generated radio wave is transmitted to the multiple access communication path 30.
Here, the code spreader 18 performs multiplexing in a spread code area by code division multiple access (CDMA). In addition, the pulse time waveform controller 10 performs multiplexing by selecting a waveform based on a pulse width.

FIG. 23 shows a configuration example of a method (transmission side, another form) in which CDMA is introduced into multiplexing by a waveform selection filter. Note that FIG. 23 illustrates the direct spreading method (DSSS method) as an example.
The transmitting communication terminal 2 has a code spreader 18 subsequent to the modulator 12. Further, in parallel with this, a code spreader 18 is provided following the pulse time waveform controller 10 (chip rate adjuster) following the CDMA spread code generator 18-1. The generator 18-1 outputs a spread code corresponding to each user, and a spread signal is generated by passing the spread code through 10. The pulse time waveform controller 10 controls the pulse width of the transmission signal by adjusting the chip rate of the spread signal so that the signal is selectively transmitted and absorbed by the waveform selection filter. That is, one chip width (reciprocal of the chip rate) is regarded as a pulse width, and by controlling this chip width, the effect of waveform selectivity is obtained.
The radio wave generated by the code spreader 18 is transmitted to the multiple access channel 30.

FIG. 24 shows a method (reception side) in which CDMA is introduced into multiplexing based on waveform selectivity.
The receiving communication terminal 2 first receives the radio wave transmitted through the multiple access communication path 30 by the waveform selection filter 20. In the waveform selection filter 20, a radio wave having a specific pulse width assigned to each transmission / reception pair is transmitted, and other radio waves are absorbed. This part realizes the selective reception of the radio wave of the assigned pulse width.
Subsequently, the code despreader 19 performs despreading using spread signals corresponding to each user, and extracts a received signal of each user.
Subsequently, the demodulator 16 demodulates the received signal and outputs a received bit sequence. In FIG. 24, the code despreader 19 and the demodulator 16 correspond to a receiving unit.

(Fifth embodiment)
FIG. 8 shows an example in which the communication terminal 2 is equipped with the pulse time waveform controller 10 and the waveform selection filter 20. The communication terminal 2 has an antenna 6 and a communication terminal internal board 2a. Since the pulse time waveform controller 10 has few components, it is mounted on a part of the board 2a in the communication terminal 2. Further, a waveform selection filter 20 is mounted outside the antenna 6. This communication terminal 2 can be used as the above-mentioned reception-side communication terminal and transmission-side communication terminal. Here, a transmission type is used as the waveform selection filter 20.
On the other hand, in the communication terminal 2 on the transmission side, a continuous signal generated by the modulator 12 and the frequency converter 14 mounted on the communication terminal internal board 2a is converted by the pulse time waveform controller 10 into a specific eigen pulse width. The signal is controlled in the time domain so as to obtain a signal as described above, and transmitted as an electric signal to the antenna 6 via the wiring 2b in the communication terminal. This electric signal is transmitted to the multiple access communication path 30 (space) by changing its form into a radio wave by the antenna 6. In the other communication terminal 2 on the receiving side, first, a radio wave having a specific pulse width is transmitted by the waveform selection filter 20, and other radio waves are absorbed. Subsequently, the antenna 6 selectively receives only a radio wave having a specific pulse width, and transmits the received signal to the frequency converter 14 and the demodulator 16 mounted on the communication terminal internal board 2a.
Here, although an example is shown in which the waveform selection filter 20 is attached to the outside of the antenna 6 built in the communication terminal 2, the antenna 6 may be provided inside the communication terminal 2. That is, the waveform selection filter 20 is connected to the antenna 6 via a so-called electromagnetic wave to be integrally formed as a communication function. Therefore, the pulse time waveform controller 10 and the waveform selection filter 20 need not be directly mechanically fastened to the antenna 6. This is because the antenna 6 of the pulse time waveform controller 10 and the waveform selection filter 20 may be fixed to the outer part of the communication terminal 2 or the like.
According to the third embodiment, by forming the waveform selection filter 20 integrally with the antenna 6 of the conventional communication terminal as a communication function via a so-called electromagnetic wave, a pulse in the same frequency band or a band in which a plurality of frequencies are present. It is possible to provide a multiplexed communication terminal 2 by selecting a waveform by width.

FIG. 25 shows the effect of multiplexing by the waveform selection filter 20 from the viewpoint of channel capacity. The horizontal axis indicates the SNR (signal-to-noise power ratio), and the vertical axis indicates the communication channel capacity (the theoretical limit value of the communication speed) of each user. As a comparison method, FIG. 25 also shows a result of the conventional method using only FDMA (indicated by “black diamonds”). The description of the percentage of the waveform selection filter 20 indicates the signal remaining rate of the unnecessary radio wave by the waveform selection filter. For example, “1%” indicates that the elimination rate of the unnecessary (unnecessary) pulse width signal is 99% and the remaining rate is 99%. Indicates that 1% of the radio waves are transmitted. Here, the number of users is set to 100. When the SNR increases (when the communication condition becomes good), the channel capacity increases. However, it is shown that the multiplexing by the waveform selection filter increases the channel capacity of each user regardless of which SNR is set. ing. Furthermore, the absorptivity of the unnecessary radio waves has a great influence on the communication channel capacity of each user. That is, the unnecessary radio waves that cannot be absorbed interfere with the necessary radio waves, resulting in deterioration of the communication channel capacity. Therefore, unnecessary radio waves can be efficiently absorbed, so that the communication channel capacity can be significantly increased. For example, when the SNR is 20 dB, it is confirmed that the communication channel capacity (frequency use efficiency) is increased about 10 times. That is, the communication channel capacity is increased from 6 Mbits / s in “black diamond” to 57.56 Mbits / s in “black square” when the signal absorption rate is 0.1%.

FIG. 26 shows the effect of multiplexing by the waveform selection filter 20 in terms of the number of users. Since the frequency band of all user signals is fixed, as the number of accommodated users increases, the communication channel capacity of each user decreases. On the other hand, it is shown that multiplexing by the waveform selection filter increases the channel capacity of each user regardless of the number of users. Further, when trying to secure a communication channel capacity of 30 Mbps for each user, the conventional FDMA method (displayed in “black diamond”) can accommodate only 10 users, whereas the method using a waveform selection filter (signal absorption rate of 0. 1) can accommodate only 10 users. (Indicated by “black square” at 1% or “black circle” at 1%) suggests that the number of accommodated users can be increased up to 100 users.

FIG. 9 shows an assumed use example (example of a wireless LAN network) of the multiple access method using the waveform selection filter 20.
FIG. 9A shows a conventional example. Interference is avoided by assigning three different frequencies f1, f2, f3 (three channels) to three users. Note that interference occurs at the same frequency (same channel). That is, as many frequencies as the number of users are required. For example, a user using the frequency f2 uses the PC 400 and uses the repeater 800.
FIG. 9B shows an embodiment. By allocating three different pulse widths for each of the three frequencies, it is possible to avoid interference at the same frequency (channel). The use of three frequencies and three pulse widths indicates that nine users can use it. For example, when the frequency f2 is used, three users can use the PCs 4a, 4b, and 4c by using three types of pulse widths. In this case, a pulse time waveform controller 10 and a waveform selection filter 20 are mounted on the PCs 4a, 4b, and 4c and the repeater 8, respectively.
Therefore, by using the pulse width, the frequency use efficiency is dramatically improved.

As described above, according to the embodiment, the concept of pulse width selectivity (waveform axis) is introduced into three axes of frequency, time, and code in the conventional communication system, and the pulse width is determined based on the pulse width in the same frequency band or a band in which a plurality of frequencies exist. A multiplexed communication system 1 and a communication terminal 2 (for example, a mobile terminal) using a waveform selection filter 20 for performing waveform selection are provided.
Invention 1 is a transmitting communication terminal 2 that transmits a radio wave by controlling a pulse width that is an excitation time of a radio wave to a specific pulse width, and a receiving communication terminal 2 that receives a radio wave transmitted by the transmitting communication terminal 2. The reception side communication terminal 2 includes a waveform selection filter 20 and a reception unit. The waveform selection filter 20 selectively transmits or reflects radio waves having a specific pulse width. 20 is a communication system that receives radio waves of a specific pulse width transmitted therethrough.
According to the first aspect, the transmitting communication terminal 2 that transmits a radio wave by controlling the pulse width, which is the excitation time of the radio wave, to a specific pulse width, and the receiving communication terminal that receives the radio wave transmitted by the transmitting communication terminal 2 The reception-side communication terminal 2 includes a waveform selection filter 20 and a reception unit. The waveform selection filter 20 selectively transmits or reflects radio waves having a specific pulse width. A multiplexed communication system 1 that receives a radio wave of a specific pulse width transmitted by the selection filter 20 can be provided. That is, the receiving side selectively receives a specific pulse width.
In a second aspect, the waveform selection filter 20 includes a conductive member 25, a rectifier circuit that connects the two portions of the conductive member 25, and one or both of the RL circuit and the RC circuit. The RL circuit includes an inductive component. The RC circuit has a circuit element having a capacitive component and a circuit element having a resistance component, and the waveform selection filter 20 has a pulse width which is an excitation time of a radio wave. It is characterized in that the radio wave absorptivity differs depending on the type.
According to the second aspect, the specific configuration of the waveform selection filter 20 is specified.
In a third aspect, the transmission-side communication terminal 2 includes a pulse time waveform controller 10 that controls a pulse width of a radio wave to a specific pulse width, and a transmission-side frequency converter 14 that performs multiplexing in a frequency domain. The radio wave transmitted by the transmitting side communication terminal 2 is controlled to a specific pulse width by the pulse time waveform controller 10 and multiplexed in the frequency domain by the transmitting side frequency converter 14. The side communication terminal 2 is characterized by having a receiving side frequency converter 14 for selectively receiving a signal in a specific frequency region among radio waves having a specific pulse width transmitted through the waveform selection filter 20.
According to the third aspect, in the communication system of the FDMA system which is frequency division, by installing the frequency converter 14 and the pulse time waveform controller 10 on the transmission side and the waveform selection filter 20 and the frequency converter 14 on the reception side, It is possible to provide a multiplexed communication system by selecting a waveform based on a pulse width.
In a fourth aspect, the transmitting communication terminal 2 includes a pulse time waveform controller 10 for controlling a pulse width of a radio wave to a specific pulse width, and a transmitting access time controller 17 for performing multiplexing by access time. The radio wave transmitted by the transmitting communication terminal 2 is controlled to a specific pulse width by the pulse time waveform controller 10 and multiplexed by the access time by the transmitting access time controller 17. The reception side communication terminal 2 has a reception side access time controller 17 for selectively receiving a signal of a specific access time among radio waves of a specific pulse width transmitted through the waveform selection filter 20. .
According to the fourth aspect, in the TDMA communication system that is time division, the access time controller 17 and the pulse time waveform controller 10 are installed on the transmission side, and the waveform selection filter 20 and the access time controller 17 are installed on the reception side. Accordingly, it is possible to provide a multiplexed communication system by selecting a waveform based on a pulse width.
In a fifth aspect, the transmission-side communication terminal 2 includes a pulse time waveform controller 10 that controls a pulse width of a radio wave to a specific pulse width, and a code spreader 18 that performs multiplexing in a spread code area. The radio wave transmitted by the transmitting communication terminal 2 is controlled to a specific pulse width by the pulse time waveform controller 10 and multiplexed in the spread code area by the code spreader 18. The terminal 2 is characterized by having a code despreader 19 for selectively receiving a signal that has been signal-spread with a specific spreading code from radio waves of a specific pulse width transmitted by the waveform selection filter 20.
According to the fifth aspect, in a CDMA communication system that is code division, a code spreader 18 and a pulse time waveform controller 10 are installed on the transmission side, and a waveform selection filter 20 and a code despreading 19 are installed on the reception side. And a multiplexed communication system by selecting a waveform based on a pulse width.
Invention 6 is a receiving communication terminal 2 that receives a radio wave from a transmitting communication terminal 2 that transmits a radio wave by controlling a pulse width, which is an excitation time of a radio wave, to a specific pulse width. A receiving communication terminal, having a receiving unit, wherein the waveform selection filter 20 selectively transmits radio waves having a specific pulse width, and the receiving unit receives radio waves having a specific pulse width transmitted by the waveform selection filter 20; 2.
According to the sixth aspect, it is possible to provide the receiving communication terminal 2 equipped with the waveform selection filter 20.
Invention 7 is characterized by including a pulse time waveform controller 10 for controlling a pulse width which is an excitation time of a radio wave to be transmitted.
According to the seventh aspect, it is possible to provide the receiving communication terminal 2 having both the transmitting function and the receiving function.
Invention 8 is a transmitting-side communication terminal 2 that transmits a radio wave to a receiving-side communication terminal 2 that selectively receives a radio wave whose pulse width, which is the excitation time of the radio wave, has a specific pulse width. The transmission-side communication terminal 2 controls the width to a specific pulse width and transmits radio waves.
According to the eighth aspect, it is possible to provide the transmitting communication terminal 2 that transmits a radio wave by controlling the pulse width of the radio wave to a specific pulse width.
As described above, the communication system 1 and the communication terminal 2 of the present invention can realize frequency utilization efficiency exceeding the limit of the conventional communication theory, and can dramatically expand a depleting radio frequency resource.

DESCRIPTION OF SYMBOLS 1 Communication system 2 Communication terminal 2a Communication terminal board 2b Communication terminal wiring 4 PC
6 antenna 8 repeater 10 pulse time waveform controller 12 modulator 14 frequency converter 16 demodulator 17 access time controller 18 code spreader 18-1 CDMA spread code generator 19 code despreader 20 waveform selection filter (waveform selection) Metasurface)
21 Inductor type waveform selection filter (absorption of long pulse width radio wave)
22 Capacitor type waveform selection filter (short pulse width radio wave absorption)
23 Parallel-Coupled Waveform Selection Filter (Concave Absorption Characteristics)
24 Series coupled waveform selection filter (convex absorption characteristics)
25 conductive member 26 dielectric 27 metal plate 30 multiple access communication path 50 simulation environment 51 transmission unit 511 pulse generation unit 52 channel unit 53 reception unit 531 comparator 532 symbol timing unit U user

Claims (8)

A transmitting communication terminal that transmits the radio wave by controlling a pulse width that is an excitation time of the radio wave to a specific pulse width, and a receiving communication terminal that receives the radio wave transmitted by the transmitting communication terminal, The receiving side communication terminal includes a waveform selection filter and a reception unit, the waveform selection filter selectively transmits or reflects the radio wave having the specific pulse width, and the reception unit includes: A communication system for receiving the transmitted radio wave having the specific pulse width. The waveform selection filter, a conductive member, a rectifier circuit connecting two places of the conductive member,
The RL circuit includes one or both of an RL circuit and an RC circuit, the RL circuit includes a circuit element having an inductive component and a circuit element having a resistive component, and the RC circuit includes a circuit element having a capacitive component and a resistor having a capacitive component. The communication system according to claim 1, further comprising a circuit element having a component, wherein the waveform selection filter has a different radio wave absorptance depending on a pulse width that is an excitation time of the radio wave. The transmission-side communication terminal includes a pulse time waveform controller that controls a pulse width of the radio wave to the specific pulse width, and a transmission-side frequency converter that performs multiplexing in a frequency domain. The radio wave transmitted by the communication terminal is controlled to the specific pulse width by the pulse time waveform controller, and is multiplexed in the frequency domain by the transmission-side frequency converter, the reception side The communication terminal according to claim 1, further comprising: a reception-side frequency converter that selectively receives a signal in a specific frequency region among the radio waves having the specific pulse width transmitted through the waveform selection filter. 3. The communication system according to 2. The transmission-side communication terminal has a pulse-time waveform controller that controls the pulse width of the radio wave to the specific pulse width, and a transmission-side access time controller that performs multiplexing with access time,
The radio wave transmitted by the transmission-side communication terminal is controlled to the specific pulse width by the pulse time waveform controller, and multiplexing at access time is performed by the transmission-side access time controller. ,
The reception-side communication terminal includes a reception-side access time controller that selectively receives a signal of a specific access time among the radio waves of the specific pulse width transmitted by the waveform selection filter. The communication system according to claim 1. The transmission-side communication terminal has a pulse time waveform controller that controls a pulse width of the radio wave to the specific pulse width, and a code spreader that performs multiplexing in a spread code area, and the transmission-side communication terminal The radio wave transmitted by the terminal is controlled to the specific pulse width by the pulse time waveform controller, and multiplexed in a spread code area by the code spreader, and the reception side communication terminal 2. The apparatus according to claim 1, further comprising: a code despreader for selectively receiving a signal that has been signal-spread with a specific spreading code among the radio waves having the specific pulse width transmitted through the waveform selection filter. Or the communication system according to 2. A transmitting communication terminal that transmits a radio wave by controlling a pulse width that is an excitation time of a radio wave to a specific pulse width, a receiving communication terminal that receives the radio wave, and has a waveform selection filter and a receiving unit. A reception-side communication terminal, wherein the waveform selection filter selectively transmits the radio wave having the specific pulse width, and the reception unit receives the radio wave having the specific pulse width transmitted through the waveform selection filter. . The receiving-side communication terminal according to claim 6, further comprising a pulse time waveform controller that controls a pulse width that is an excitation time of a radio wave to be transmitted. The pulse width, which is the excitation time of the radio wave, has a specific pulse width, and has a waveform selection filter and a receiving unit.The waveform selection filter selectively transmits or reflects the radio wave having the specific pulse width. , the receiving unit, the receiving communication terminal that the waveform selection filter for receiving the radio wave of the particular pulse widths transmitted, a transmitting communication terminal for transmitting the electric wave, the pulse width of the radio wave A transmitting communication terminal that transmits the radio wave by controlling the pulse width to a specific value.