Signal generation circuit and communication system

Abstract

To provide a signal generation circuit for generating a prime number distribution function value on the basis of a prime number theorem by using an inexpensive electronic device without requiring a computer.SOLUTION: The signal generation circuit 10 is a circuit for generating a prime number distribution function value according to the prime number theorem, and includes a capacitor 15 as a charge emission source for emitting charges due to thermal energy, a transistor 14 as a number generator for generating a number signal corresponding to the number of charges emitted from the charge emission source, a timer circuit 22 as a time ratio generator for generating a time ratio signal corresponding to a division value obtained by dividing an elapsed time from an initial time by an initial time until a predetermined number of charges are emitted from the charge emission source after the initial time, and an arithmetic circuit 23 as a prime number distribution function value generator for generating, as a prime number distribution function value, a signal obtained by dividing a value indicated by the time ratio signal generated by the time ratio generator by a value indicated by the number signal generated by the number generator.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a signal generating circuit that generates prime distribution function values ​​based on the prime number theorem, and a communication system that includes the signal generating circuit. [Background technology]

[0002] Prime numbers are used in a variety of technologies, including suppressing signal interference in multi-channel communication systems based on random sequence signals (codes) using prime numbers, controlling robots quickly and precisely based on smooth control using prime numbers, and suppressing mechanical fatigue by determining the number of gears based on prime numbers and controlling the rotation angle of a motor.

[0003] In a prime generation device that generates such useful prime numbers, calculation of the probability of occurrence of prime numbers is performed as an auxiliary function (see, for example, Patent Document 1). Patent Document 1 discloses that the operation of generating prime numbers by the prime generation device according to Patent Document 1 is verified using the probability of occurrence of prime numbers calculated based on the prime number theorem as a theoretical value.

[0004] Here, the prime number theorem is a theorem that states that the number of prime numbers π(x) less than or equal to a certain natural number x asymptotically approaches x / ln(x), as shown in Figure 1. ln(x) is the natural logarithm of x. Figure 1 is a diagram showing the relationship between the natural number x (horizontal axis) and the number of prime numbers π(x) less than or equal to x, based on the prime number theorem. The number of prime numbers π(x) calculated according to the prime number theorem is also called the prime number distribution function value. The probability p(x) of occurrence of a prime number calculated based on the prime number theorem is p(x) = π(x) / x = 1 / ln(x).

[0005] Conventionally, a technology for supporting calculations based on the prime number theorem has also been proposed (see, for example, Patent Document 2). Patent Document 2 discloses a program that reduces the burden on a computer and detects the number of prime numbers that exist below a certain value. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-099212 [Patent Document 2] Japanese Patent Application Publication No. 2016-028307 [Non-patent literature]

[0007] [Non-Patent Document 1] IEEE Transactions on Electron Devices,Vol.68,pp.1723,April(2021) Summary of the Invention [Problem to be solved by the invention]

[0008] However, both the prime number generation device disclosed in Patent Document 1 and the program for detecting the number of prime numbers disclosed in Patent Document 2 are technologies based on calculations by a computer, and have the problem of requiring a computer for the calculations.

[0009] Therefore, an object of the present disclosure is to provide a signal generating circuit and a communication system that generate prime distribution function values ​​based on the prime number theorem using inexpensive electronic devices without requiring a computer. [Means for solving the problem]

[0010] In order to achieve the above object, a signal generation circuit according to one embodiment of the present disclosure is a signal generation circuit that generates a prime number distribution function value based on the prime number theorem, and includes: a charge emitting source that emits charges due to thermal energy; a number generator that generates a number signal that is a signal corresponding to the number of charges emitted from the charge emitting source; a time ratio generator that generates a time ratio signal that is a signal corresponding to a divided value obtained by dividing a time elapsed from an initial time by an initial time that is a time until a predetermined number of charges are emitted from the charge emitting source after the initial time; and a prime number distribution function value generator that generates a signal obtained by dividing a value indicated by the time ratio signal generated by the time ratio generator by the value indicated by the number signal generated by the number generator, as the prime number distribution function value.

[0011] In order to achieve the above object, a communication system according to one embodiment of the present disclosure comprises the above signal generating circuit, a transmitter having a plurality of transmission channels provided corresponding to each of a plurality of timings corresponding to the emission timing signal generated by the emission timing generator, and transmitting a predetermined signal at the corresponding timing, and a receiver having a plurality of reception channels provided corresponding to each of the plurality of transmission channels, and receiving the predetermined signal transmitted from the corresponding transmission channel. [Effects of the Invention]

[0012] The present disclosure provides a signal generating circuit and a communication system that generates prime distribution function values ​​based on the prime number theorem using inexpensive electronic devices without requiring a computer. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing the relationship between a natural number x (horizontal axis) and the number of prime numbers equal to or less than the natural number x, π(x), based on the prime number theorem. [Figure 2] FIG. 2 is a circuit diagram of a signal generating circuit according to an embodiment. [Figure 3] FIG. 3 is a circuit diagram of a signal generating circuit according to a modified example of the embodiment. [Figure 4]FIG. 4 is a block diagram illustrating a configuration of a communication system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that each embodiment described below represents a specific example of the present disclosure. Numerical values, circuit elements, connection forms of circuit elements, signal processing, timing of signal processing, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, each drawing is not necessarily an exact illustration. In each drawing, substantially identical configurations are assigned the same reference numerals, and redundant explanations are omitted or simplified. Furthermore, "connection" means electrical connection, and includes not only cases where two circuit elements are directly connected, but also cases where two circuit elements are indirectly connected with another circuit element inserted between them.

[0015] First, in order to explain the signal generating circuit and the communication system according to the embodiment, a physical phenomenon utilized by the signal generating circuit according to the embodiment will be explained.

[0016] The average time it takes for the charges stored in a charge emission source, a capacitor with capacitance C, to be released due to thermal energy. <t k-1 It is known that > ​​follows the following formula 1 (see Non-Patent Document 1).

[0017]

number

[0018] where q is the elementary charge and k B is the Boltzmann factor, T is the absolute temperature, and λ is the emission rate of the charge at the initial time.

[0019] Here, the initial time <t0>, that is, the average time it takes for one charge (k=1) to be released <t0>is expressed as the following equation 2,

[0020]

number

[0021] By dividing both sides of the above equation 1 by both sides of the above equation 2, λ0 etc. are eliminated, and the following equation 3 is derived.

[0022]

number

[0023] By taking the natural logarithm ln of both sides of the above equation 3, the following equation 4 is derived.

[0024]

number

[0025] Here, let x be the natural number in the prime number theorem: <t k-1 > / <t0>By replacing it with, the following formula 5 holds.

[0026]

number

[0027] ln( <t k-1 > / <t0>), the above formula 5 is transformed into the following formula 6.

[0028]

number

[0029] Here, the change in voltage V when (k-1) charges q are released from a capacitor with capacitance C is k-1 But V k-1 =q·(k-1) / C, we can use the formula (k-1)=V k-1 By substituting C / q, the above equation 6 is transformed into the following equation 7.

[0030]

number

[0031] where K={(k B ·T) / q} (constant).

[0032] From the above formula 7, the prime number distribution function value π( <t k-1 > / <t0>)teeth, <t k-1 > / <t0>For the change voltage V k-1 It can be seen that this corresponds to the signal obtained by dividing <t k-1 > / <t0>is the average time it takes for k charges to be released <t k-1 > is the average time it takes for a given number of charges (here, one) to be released. <t0>The time ratio signal is obtained by dividing the voltage V k-1 is the voltage change when k charges q are released from a capacitor with capacitance C, and can be said to be a number signal, which is a signal corresponding to the number of charges released from the charge release source.

[0033] The signal generating circuit according to this embodiment utilizes the relational expression shown in Equation 7 above to generate the prime number distribution function value π( <t k-1 > / <t0>) is a circuit that calculates

[0034] Fig. 2 is a circuit diagram of a signal generating circuit 10 according to an embodiment. More specifically, Fig. 2(a) shows a circuit diagram of the signal generating circuit 10, and Fig. 2(b) is a potential diagram of the capacitor 15 and the reset transistor in Fig. 2(a).

[0035] The signal generating circuit 10 is a circuit that generates prime number distribution function values ​​based on the prime number theorem using inexpensive electronic devices without requiring a computer, and includes transistors 11 to 14 such as NMOS transistors, capacitors 15 and 16, a resistor 17, a synchronization circuit 20, a RST (reset signal) generating circuit 21, a timer circuit 22, and an arithmetic circuit 23. The signal generating circuit 10 is realized, for example, by a one-chip semiconductor integrated circuit.

[0036] Capacitor 15 is an example of a charge emission source that emits charge due to thermal energy, such as a floating diffusion (FD) formed in a semiconductor integrated circuit. Specifically, after capacitor 15 is reset by transistor 11, the charge stored in capacitor 15 is released one after another at random timings to capacitor 16 via transistor 12 due to thermal energy, as shown in FIG. 2(b).

[0037] The capacitor 16 has capacitance as a drain to which the charge accumulated in the capacitor 15 is discharged, and is, for example, a junction capacitance of a photodiode as an imaging element.

[0038] When a reset signal, which is a pulse signal from the RST generating circuit 21, is input to the gate terminal of the transistor 11, the transistor 11 turns on, and applies a constant voltage Vsb (e.g., 0 V) ​​to the capacitor 15 connected to the transistor 11, thereby resetting the capacitor 15.

[0039] Similarly, when a reset signal is input to the gate terminal from the RST generating circuit 21, the transistor 13 turns on, thereby applying a constant voltage VDD to the capacitor 16 connected to the transistor 13, thereby resetting it.

[0040] A constant voltage Vbias is applied to the gate terminal of transistor 12, which is in a soft off state, and a soft transfer of charge from capacitor 15 to capacitor 16 (that is, a soft reset) is realized.

[0041] The transistor 14 is an example of a number generator that generates a number signal, which is a signal corresponding to the number of charges emitted from the charge emission source. Specifically, the gate terminal of the transistor 14 is connected to the connection point FD between the transistor 11 and the capacitor 15, and the transistor 14 operates as a source follower amplifier. A voltage corresponding to the potential of the connection point FD input to the gate terminal of the transistor 14, that is, the above-mentioned changing voltage V, is output from the connection point between the transistor 14 and the resistor 17 (i.e., the source of the transistor 14). k-1 will be output.

[0042] In this embodiment, it is assumed that the capacitor 15 is reset to 0 V, and the transistor 14 changes the voltage corresponding to the potential of the connection point FD to a voltage V k-1 However, if the capacitor 15 is reset to a predetermined voltage other than 0 V (for example, 3 V), a differentiation circuit or a CDS (Correlated Double Sampling) circuit or the like that detects the change in the voltage at the node FD may be provided between the node FD and the transistor 14.

[0043] Furthermore, the circuit configured by the transistors 11 to 14, the capacitors 15 and 16, and the resistor 17 can be replaced with a pixel circuit of a CMOS image sensor.

[0044] The synchronization circuit 20 simultaneously outputs to the RST generation circuit 21 and the timer circuit 22 a signal that initializes the generation of prime distribution function values ​​based on the prime number theorem (that is, an initialization signal that indicates the initial time).

[0045] When the RST generating circuit 21 receives the initialization signal output from the synchronization circuit 20, it outputs a reset signal, which is a pulse signal that temporarily turns on the transistors 11 and 13 simultaneously.

[0046] The timer circuit 22 is an example of a time ratio generator that generates a time ratio signal, which is a signal corresponding to a divided value obtained by dividing the elapsed time from the initial time by the initial time, which is the time until a predetermined number of charges are discharged after the initial time. Specifically, in this embodiment, when the timer circuit 22 receives the initialization signal output by the synchronization circuit 20, it counts the elapsed time from that time (initial time) (i.e., <t k-1 >), and measures the initial time (i.e., <t0>) is read from the internal memory where it is stored in advance, or is measured and acquired using a measuring device (not shown), and the elapsed time <t k-1 > for the initial time <t0>A time ratio signal (i.e., <t k-1 > / <t0>) is repeatedly output over time.

[0047] The arithmetic circuit 23 is an example of a prime number distribution function value generator that generates a signal obtained by dividing a value indicated by a time ratio signal generated by a time ratio generator (i.e., clock circuit 22) by a value indicated by a number signal generated by a number generator (i.e., transistor 14), as a prime number distribution function value. Specifically, the arithmetic circuit 23 receives the time ratio signal (i.e., <t k-1 > / <t0>) is input, the time ratio signal (i.e., <t k-1 > / <t0>) to the number signal output from the source of transistor 14 (i.e., V k-1 ) to obtain the signal {( <t k-1 > / <t0>) / V k-1 } into the prime distribution function value (i.e., π( <t k-1 > / <t0>At this time, the calculation circuit 23 outputs the time ratio signal <t k-1 > / <t0>and number signal V k-1 The division can be performed on the analog signal, or on the time ratio signal <t k-1 > / <t0>and number signal V k-1 may be converted to a digital signal and then division may be performed between the digital values.

[0048] The signal generating circuit 10 according to this embodiment configured as above operates as follows.

[0049] First, upon receiving the initialization signal output from the synchronization circuit 20, the RST generation circuit 21 outputs a reset signal that simultaneously and temporarily turns on the transistors 11 and 13. This resets the capacitors 15 and 16, and thereafter, the charge stored in the capacitor 15, which serves as a charge release source, is successively released to the capacitor 16 via the transistor 12 due to thermal energy.

[0050] In parallel with the above charge emission, when the timing circuit 22 receives the initialization signal output from the synchronization circuit 20, it counts the elapsed time from that time (initial time) using an internal timer. <t k-1 The initial time is the time from the initial time until a predetermined number of charges (here, one) are discharged. <t0>is read from the internal memory where it has been stored in advance, or is measured and acquired using a measuring device (not shown), and the elapsed time <t k-1 > for the initial time <t0>A time ratio signal that corresponds to the division value obtained by dividing by <t k-1 > / <t0>The signal corresponding to the signal is repeatedly output over time.

[0051] The calculation circuit 23 receives the time ratio signal from the timer circuit 22. <t k-1 > / <t0>Whenever is input, the time ratio signal <t k-1 > / <t0>The number signal V output from the transistor 14 k-1 By dividing by, the resulting signal {( <t k-1 > / <t0>) / V k-1 } to the prime number distribution function value π( <t k-1 > / <t0>)

[0052] In this way, the signal generating circuit 10 according to the embodiment realizes a circuit that generates prime distribution function values ​​based on the prime number theorem using inexpensive electronic devices (here, a capacitor or the like as a charge emission source) without requiring a computer.

[0053] Fig. 3 is a circuit diagram of a signal generating circuit 10a according to a modified example of the embodiment. More specifically, Fig. 3(a) shows the circuit diagram of the signal generating circuit 10a, and Fig. 3(b) is a potential diagram of the capacitor 15 in Fig. 3(a).

[0054] A signal generating circuit 10a according to this modification is configured such that the capacitor 16 is replaced with an avalanche photodiode (APD) 16a in the signal generating circuit 10 according to the embodiment, and further a measuring circuit 25 is added. The following mainly describes the differences from the embodiment.

[0055] The APD 16a is an example of an amplifier that amplifies the voltage at the connection point FD, in other words, amplifies a number signal that corresponds to the number of charges emitted from the charge emission source. The anode of the APD 16a is connected to a substrate voltage (Vsub) or the like.

[0056] Measurement circuit 25 is an example of a release timing generator that generates a release timing signal that indicates the timing at which charge is released from capacitor 15, which is the charge release source. Specifically, measurement circuit 25 incorporates a differentiation circuit that differentiates the number signal after amplified by APD 16a, a comparator that detects when the differentiated number signal exceeds a threshold, and the like, and outputs a pulse signal that indicates the timing at which the differentiated number signal exceeds the threshold to the outside as a release timing signal.

[0057] According to the signal generating circuit 10a of this modification, the prime number distribution function value π( <t k-1 > / <t0>), a discharge timing signal indicating the timing at which the charge is discharged from the capacitor 15, which is the charge discharge source, is also output. Therefore, the prime number distribution function value π( <t k-1 > / <t0>) and the emission timing signal, the external device synchronizes with the pulse signal indicated by the emission timing signal to obtain the prime number distribution function value π( <t k-1 > / <t0>) to obtain the prime distribution function value π( <t k-1 > / <t0>), the newly generated prime number distribution function value π( <t k-1 > / <t0>) can be obtained.

[0058] 4 is a block diagram showing the configuration of a communication system 30 according to an embodiment. The communication system 30 is a communication system that applies a signal generating circuit 10a according to a modified example of the embodiment, and is composed of the signal generating circuit 10a according to the modified example of the embodiment, a transmitter 31 connected to the signal generating circuit 10a, and a receiver 32 that receives a transmission signal from the transmitter 31. It can also be said that the signal generating circuit 10a and the transmitter 31 constitute a transmitting device, and the receiver 32 constitutes a receiving device.

[0059] The transmitter 31 is provided corresponding to each of a plurality of timings corresponding to the emission timing signal generated by the emission timing generator (i.e., the measurement circuit 25) of the signal generating circuit 10a, and has a plurality of transmission channels (Tr.1) 31a, transmission channel (Tr.2) 31b, ... transmission channel (Tr.N) 31c that transmit predetermined signals at the corresponding timings. Here, the predetermined signal is, for example, a prime number distribution function value π( <t k-1 > / <t0>In this case, the first transmission channel 31a may be a channel having a timing signal output from the signal generating circuit 10a. <t k+1 At the timing when the prime number distribution function value π( <t k+1 > / <t0>), and the next transmission channel 31b outputs the emission timing signal from the signal generating circuit 10a. <t k+2 At the timing when the prime number distribution function value π( <t k+2 > / <t0>), and the Nth transmission channel 31c outputs the emission timing signal from the signal generating circuit 10a. <t k+N At the timing when the prime number distribution function value π( <t k+N > / <t0>) is output.

[0060] The receiver 32 is provided corresponding to each of a plurality of transmission channels (Tr.1) 31a, transmission channel (Tr.2) 31b, ... transmission channel (Tr.N) 31c, and has a plurality of reception channels (R.1) 32a, reception channel (R.2) 32b, ... reception channel (RN) 32c that receive predetermined signals transmitted from the corresponding transmission channels.

[0061] According to such a communication system 30, each of the multiple transmission channels 31a to 31c transmits a predetermined signal at a timing when the release timing signal from the signal generating circuit 10a indicates the release of charge from the capacitor 15, i.e., at random timing, thereby suppressing signal interference in the multi-channel communication system.

[0062] Furthermore, the prime number distribution function value π( <t k-1 > / <t0>), in the receiver 32, each of the receiving channels 32a to 32c sequentially receives the updated prime distribution function value π( <t k+n > / <t0>) can be obtained.

[0063] Note that the predetermined signals transmitted through the plurality of transmission channels 31a to 31c do not necessarily have the same prime distribution function value π( <t k-1 > / <t0>), and may be any signal or a fixed signal.

[0064] The above description of the embodiment and modifications discloses the following techniques.

[0065] (Technology 1) A signal generation circuit that generates a prime number distribution function value based on the prime number theorem, comprising: a charge emitting source that emits charges due to thermal energy; a number generator that generates a number signal that is a signal corresponding to the number of charges emitted from the charge emitting source; a time ratio generator that generates a time ratio signal that is a signal corresponding to a divided value obtained by dividing an elapsed time from an initial time by an initial time that is a time until a predetermined number of charges are emitted from the charge emitting source after the initial time; and a prime number distribution function value generator that generates a signal obtained by dividing a value indicated by the time ratio signal generated by the time ratio generator by the value indicated by the number signal generated by the number generator, as the prime number distribution function value.

[0066] As a result, prime number distribution function values ​​are generated based on the prime number theorem by an electronic circuit that utilizes the physical phenomenon of charge being emitted from a charge emission source due to thermal energy, and therefore a signal generating circuit that generates prime number distribution function values ​​based on the prime number theorem can be realized using inexpensive electronic devices without requiring a computer.

[0067] (Technology 2) The signal generating circuit of Technology 1 further comprises an emission timing generator that generates an emission timing signal indicating the timing at which charges are emitted from the charge emission source. Thus, an external device that receives the prime distribution function value and the emission timing signal output from the signal generating circuit receives the prime distribution function value in synchronization with the emission timing signal, and can obtain successively newly generated prime distribution function values ​​in synchronization with the update of the prime distribution function value.

[0068] (Technology 3) The signal generating circuit of Technology 2, wherein the emission timing generator generates the emission timing signal based on a differential value of the number signal. This allows the emission timing signal indicating the timing at which charges are emitted from the charge emission source to be generated with a simple circuit.

[0069] (Technology 4) The signal generating circuit of Technology 3 further includes an amplifier that amplifies the number signal, and the emission timing generator generates the emission timing signal based on a differential value of the number signal after it has been amplified by the amplifier. As a result, the number signal is differentiated after it has been amplified, so that the timing at which charges are emitted from the charge emission source can be reliably detected with high accuracy, and the emission timing signal is generated.

[0070] (Technology 5) The signal generating circuit of Technology 4, wherein the amplifier is an avalanche photodiode. This allows the number signal to be amplified with a simple electronic device.

[0071] (Technology 6) The signal generating circuit according to any one of Technologies 1 to 5, wherein the charge emission source is a capacitor. This allows the charge emission source to be realized by a simple electronic device.

[0072] (Technology 7) A communication system comprising: a signal generating circuit according to any one of technologies 2 to 5; a transmitter having a plurality of transmission channels provided corresponding to each of a plurality of timings corresponding to the emission timing signals generated by the emission timing generator, the transmission channels transmitting predetermined signals at the corresponding timings; and a receiver having a plurality of reception channels provided corresponding to each of the plurality of transmission channels, receiving the predetermined signals transmitted from the corresponding transmission channels.

[0073] As a result, each of the multiple transmission channels transmits a predetermined signal at a timing when the emission timing signal from the signal generating circuit indicates the emission of charge from the charge emission source, i.e., at random timing, thereby suppressing signal interference in multi-channel communication systems.

[0074] (Technology 8) The communication system of Technology 7, wherein the predetermined signal is a signal corresponding to a prime distribution function value generated by the prime distribution function value generator included in the signal generation circuit at the corresponding timing. This allows each of the multiple receiving channels to obtain an updated prime distribution function value in turn.

[0075] While the signal generating circuit and communication system according to the present disclosure have been described above based on the embodiments and modifications, the present disclosure is not limited to these embodiments and modifications. As long as they do not deviate from the gist of the present disclosure, various modifications that would occur to a person skilled in the art to the present embodiments and modifications, and other forms constructed by combining some of the components of the embodiments and modifications, are also included within the scope of the present disclosure.

[0076] For example, in the above-described embodiments, the signal generating circuit sets the initial time to t0 and generates the prime number distribution function value π( <t k-1 > / <t0>) is illustrated, the initial time is not limited to this value. For example, the initial time may be set to t1 and the prime number distribution function value π( <t k-1 > / <t1>) may be a circuit that calculates

[0077] Furthermore, in the above-described embodiments, the signal generating circuit is provided with a transistor 12 that enables a soft reset, but a soft reset is not necessarily required, and whether or not to adopt it can be determined as appropriate depending on the specifications required as a noise countermeasure in signal processing.

[0078] In addition, in the above embodiments, the capacitor 15 in the signal generating circuit is a floating diffusion (FD), but this is not limited to this and may be a capacitor, a diode junction capacitance, a photodiode junction capacitance, etc. [Industrial Applicability]

[0079] The present disclosure can be utilized as a signal generating circuit that generates prime number distribution function values ​​based on the prime number theorem, and a communication system including the signal generating circuit, and in particular as a signal generating circuit and a communication system that generate prime number distribution function values ​​based on the prime number theorem using inexpensive electronic devices without requiring a computer. [Explanation of symbols]

[0080] 10, 10a Signal generating circuit 11-14 Transistors 15, 16 Capacitor 16a Avalanche Photodiode (APD) 17 Resistance 20 Synchronous Circuit 21 RST (reset signal) generation circuit 22 Timing circuit 23 Arithmetic circuit 25 Measurement circuit 30 Communication Systems 31 Transmitter 31a~31c Transmitting channels (Tr.1~Tr.N) 32 Receiver 32a~32c Receiving channels (R.1~RN)

Claims

1. A signal generating circuit for generating a prime number distribution function value based on the prime number theorem, a charge emission source that emits electric charges due to thermal energy; a number generator for generating a number signal corresponding to the number of charges emitted from the charge emission source; a time ratio generator for generating a time ratio signal corresponding to a quotient obtained by dividing an elapsed time from an initial time by an initial time, which is a time required for a predetermined number of charges to be emitted from the charge emitting source after the initial time; a prime number distribution function value generator that generates, as the prime number distribution function value, a signal obtained by dividing a value indicated by a time ratio signal generated by the time ratio generator by a value indicated by a number signal generated by the number generator. Signal generation circuit.

2. further comprising an emission timing generator for generating an emission timing signal indicating the timing at which charges are emitted from the charge emission source.

2. The signal generating circuit according to claim 1.

3. the emission timing generator generates the emission timing signal based on a differential value of the number signal; 3. The signal generating circuit according to claim 2.

4. further comprising an amplifier for amplifying the number signal; the emission timing generator generates the emission timing signal based on a differential value of the number signal after being amplified by the amplifier; 4. The signal generating circuit according to claim 3.

5. the amplifier is an avalanche photodiode; 5. The signal generating circuit according to claim 4.

6. the charge emission source is a capacitor; 2. The signal generating circuit according to claim 1.

7. A signal generating circuit according to any one of claims 2 to 5; a transmitter having a plurality of transmission channels provided corresponding to the plurality of timings corresponding to the emission timing signals generated by the emission timing generator, the transmission channels transmitting predetermined signals at the corresponding timings; a receiver having a plurality of receiving channels provided corresponding to the plurality of transmitting channels, for receiving the predetermined signals transmitted from the corresponding transmitting channels; Communication system.

8. the predetermined signal is a signal corresponding to a prime distribution function value generated by the prime distribution function value generator included in the signal generation circuit at the corresponding timing; 8. The communication system according to claim 7.

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