JP2000209129A - Transmission timing generating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent data collection from receiving any hindrance even one time of transmission data is missing on the occurrence of a power failure in the case that a code length of a pseudo random code stream is selected short so that the size of transmission data at one time is contained within a range of a permissible error of data collection. SOLUTION: An address of each transmitter S provided to a watthour meter WHM of each consumer is recognized (step 101), and a pseudo random code stream is generated by using a specific value to each transmitter S such as an address of each transmitter S for an initial value is generated (step 102). Each transmitter S uses this code stream to generate a transmission timing (step 103). In this case, the code length of the code stream is selected short to a degree that the size of transmission data at one time is contained within a permissible error of collected data. Furthermore, a fixed time length is added at an initial state of generating the transmission timing and a timing when an external cause is generated is used for a succeeding generating timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates a transmission timing for transmitting data from each transmitter to a receiver in a communication system in which one-way communication is performed from a plurality of transmitters to one receiver by code division multiplexing. It is about the method.

[0002]

2. Description of the Related Art Conventionally, data transmission from a transmitter to a receiver in this type of communication system is generally triggered by an external factor such as a change in transmission information data as a trigger to generate transmission timing.

[0003] As such a communication system, for example, there is an automatic meter reading system that collects data on the amount of electric power used by each customer using a distribution line or a dedicated line, and automatically reads the meter. FIG. 9 illustrates a schematic configuration of the automatic meter reading system. A transmitter S is attached to the watt hour meter WHM of each consumer, and these transmitters S are connected in multi-drop to a line W such as a distribution line or a dedicated line.
A transformer T for supplying power to each customer is provided on the track W, and a meter reading device C and a receiver R are provided on the track W at the end of the transformer T on the customer side.

[0004] Each transmitter S transmits the power consumption data to the line W every time the power consumption of the watt hour meter WHM increases by a certain amount, that is, at a transmission timing triggered by a certain change of the transmission information data. Send out. This data is superimposed as a signal on the AC power supply wave of the line W and received by the receiver R. The meter reading device C takes in the data sent from each transmitter S via the receiver R and stores the data for each customer.
Then, the meter reading device C totals the acquired data for a certain period, for example, every month.

[0005]

However, in the above-described conventional transmission timing generation method, the transmission timing is generated by using a certain amount of change in the amount of power used by the watt hour meter WHM as an external factor. If there is no change in power consumption in the absence, no data is transmitted from the transmitter S at all. Further, if the change in the power consumption is gradual due to the absence of the customer for a long period of time, the number of transmissions of the transmitter S within a certain period of time decreases extremely. The transmission data disappears while propagating W, and data collected by the meter reading device C is lost.
As a result, data is collected only a very small number of times within a certain period, or data cannot be collected at all within a certain period.

[0006] As described above, data collection from a customer performed within a certain period is performed only a very small number of times,
Otherwise, if it is not performed even once, it is difficult to distinguish whether the communication system has an abnormality and is in such a state or the customer is in such a state without a long term absence. Therefore, it becomes difficult to maintain and manage the automatic meter reading system by the conventional transmission timing generation method.

[0007] Further, the communication system includes a plurality of transmitters S connected to a single line W. For this reason, depending on the transition of the power consumption of each customer, the power consumption data is simultaneously transmitted from the transmitters S of different customers to the line W, and a collision occurs between the transmission signals. Thus, even when a collision occurs between the transmission signals, data collected by the meter reading device C is lost, and accurate data collection cannot be performed.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and has been made by a plurality of transmitters.
In a communication system that performs one-way communication with one receiver and collects data from each transmitter received by the receiver at regular intervals, the same value as an initial value is used as a unique value set for each transmitter. Starting from the reference timing, a pseudo-random code sequence having a short code length is generated such that the size of one transmission data is small enough to fall within the allowable error range of the collected data, and based on the pseudo-random code sequence. Generate a transmission timing for each transmitter.

As described above, when the transmission timing of each transmitter is generated based on a pseudo-random code sequence starting from the same reference timing, for example, an M-sequence or an OCC code sequence, using a value unique to each transmitter as an initial value, Transmission timing with little cross-correlation between devices can be generated.

Further, the code length of each pseudo random code is
If the size of one transmission data is set short enough to fall within the tolerance of the collected data, even if one transmission data is lost due to a power failure, There is no hindrance to data collection.

Further, the code length is set to be short in this way,
When the transmission timing is generated irrespective of the change amount of the transmission data, the receiver frequently receives a signal from the transmitter regardless of the change amount of the transmission data.

Further, according to the present invention, in a communication system in which a plurality of transmitters perform one-way communication with one receiver, a pseudo address starting from the same reference timing with a unique address value set for each transmitter as an initial value. A random code sequence is generated, and a transmission timing of each transmitter is generated from a timing shifted from the reference timing by a fixed long time peculiar to each transmitter which is not synchronized with a minimum unit of a code constituting the pseudo random code sequence.

Also in this method, since the transmission timing of each transmitter is generated based on a pseudo-random code sequence starting from the same reference timing using a value unique to each transmitter as an initial value, cross-correlation between the transmitters is generated. It is possible to generate fewer transmission timings.

Signals transmitted from each transmitter collide with each other for each code length of the pseudo-random code string. In this way, the generation of the transmission timing of each transmitter is based on a fixed long time unique to each transmitter. By performing from the timing shifted from the timing, the end timing of one code sequence of each pseudo random code sequence is different from each other.

Further, the present invention provides a communication system in which a plurality of transmitters perform one-way communication with one receiver, and a pseudo address starting from the same reference timing with a unique address value set for each transmitter as an initial value. Generate a random code sequence, generate the transmission timing of each transmitter based on this pseudo-random code sequence, and determine the next transmission timing by the code constituting the pseudo-random code sequence when an external factor occurs. Instead, the occurrence timing of the external factor is set as the next transmission timing, and the subsequent transmission timing is determined again by the codes constituting the pseudo random code sequence.

Also in this method, since the transmission timing of each transmitter is generated based on a pseudo-random code sequence starting from the same reference timing using a value unique to each transmitter as an initial value, cross-correlation between the transmitters is generated. It is possible to generate fewer transmission timings.

Further, when an external factor occurs, instead of determining the next transmission timing by the code constituting the pseudo-random code sequence, the external factor occurrence timing is set as the next transmission timing, so that the external factor is reduced. One code string end timing of the pseudo random code string assigned to the added transmitter becomes different from one code string end timing of the pseudo random code string assigned to the other transmitters.

[0018]

Next, a description will be given of a first embodiment in which the transmission timing generation method according to the present invention is applied to the above-described automatic meter reading system shown in FIG. FIG. 1 is a flowchart illustrating a transmission timing generation method according to the present embodiment.

First, the address value of each transmitter S provided in the watt hour meter WHM of each consumer is recognized (step 1).
01). In this embodiment, there are ten transmitters S, and each transmitter S is assigned a unique value of address 1 to address 10. Next, a pseudo-random code sequence is generated with a value unique to each transmitter S, for example, an address value of each transmitter S as an initial value (step 102).

A typical M-sequence is a typical pseudo-random code string. As shown in FIG. 2A, an M-sequence generator includes four shift registers 1 to 4 and one feedback tap (EXO).
R) 5 and [4, 1] M-sequence generator, as shown in FIG. 3 (b), each transmitter S of addresses 1 to 10 generates an M-sequence as shown.

Each transmitter S generates a transmission timing using the codes constituting each of the M sequences (step 103 in FIG. 1). That is, as shown in FIG.
The transmitter S of codes 1,8,12, using ..., transmitted from the reference timing _{T 0} to 1 × 18 (= 18) minutes after the timing _{T 1,} the transmission timing _{T 1} from 8 × 18 (= 1
44) The transmission timing T ₂ and the transmission timing T ₂ after minutes
12 × 18 (= 216) minutes after the transmission timing T ₃
Thus, the transmission timing is sequentially generated.

Further, as shown in FIG.
The transmitter S of, using the code 2,1,8 ..., transmitted from the reference timing _{T 0} to 2 × 18 (= 36) minutes after the timing _{T 1,} the transmission timing _{T 1 1 × 18 (= 18} )
Minutes later, the transmission timing T ₂ and the transmission timing T ₂ to 8
× 18 (= 144) minutes after successively generates transmission timing so that the transmission timing _{T 3.} Similarly, each of the transmitters S of the other addresses 3 to 10 sequentially generates transmission timing in the same manner.

In the present embodiment, since the real-time property is not so important for the automatic meter reading system, a pseudo random number is generated inside the transmitter S, and the transmission timing of each transmitter S is determined by using the pseudo random number code string. Has been generated as follows. When pseudo random numbers are used, the correlation of the random numbers becomes a problem. When the M-sequence, which is a representative pseudo-random number, is sorted by the address value of the transmitter S as described above, each transmitter S
If the pseudo-random numbers generated in ( ₁₎ start from the same reference timing T0, since the M-sequence has excellent autocorrelation characteristics, it is possible to generate the transmission timing of each of the transmitters S with little mutual correlation.

Since no separate open / close switch is provided between the transmitters S, the power outage and restoration of power to each customer occurs simultaneously. Therefore, even when a power failure occurs, the transmission control program of each transmitter S starts all at once, and can generate a transmission timing with low correlation.

Further, the code length of the M-sequence is set to a short value such that the size of one transmission data is small enough to fall within the allowable error range of the collected data. In the case of this embodiment in which the power consumption data from each transmitter S is collected every month, the code length of the M sequence is, for example, one and a half (36 days).
Hours). The code length is the sum of the values of each code in one code sequence. In the case of the above-described M sequence, the code length is 120, and therefore, the time per unit code is 18
Minute (= 36 × 60 ÷ 120).

When the time per unit code is set to this level, the size of one transmission data from each consumer is determined by the amount of collected data in the power consumption data collected in one month. Within the allowable error range. If the code length of the pseudo-random code is set to be extremely short as compared with the data collection period of the power consumption, a power outage of power supplied from the transformer T to each customer occurs, and the transmitter Even if S stops and one transmission data is lost, there is no problem in collecting data for one month.

In contrast, in the conventional transmission timing generation method, the power consumption of the watt hour meter WHM is, for example, 1 kWh.
If the transmission timing is generated each time the number increases, 1
The size of the transmission data at a time is 1 KWh. For this reason,
If the increase in power consumption is gradual due to the absence of the customer for a long period of time and the number of transmissions decreases extremely, the weight of one transmission data increases, and the loss of one transmission data indicates the power consumption for one month. In view of the quantity data, this corresponds to a large weighing error.

Further, the code length is set to be short in this way,
When the transmission timing is generated irrespective of the change amount of the transmission data, the receiver R frequently receives a signal from the transmitter S irrespective of the change amount of the transmission data. Therefore, even when the customer is absent for a long period of time, if the system is operating normally, a signal is frequently taken into the meter reading device C, so that the maintenance management of the automatic meter reading system becomes easy.

In the above description of the embodiment, the pseudo random code sequence is described as an M sequence, but the pseudo random code sequence may be an OCC code sequence. This code sequence is one of spread code sequences when spreading by a spread spectrum FH (frequency hopping) method.
This is illustrated in FIG. As shown in the figure,
In the OCC code sequence, all numbers occur once in the sequence.

This OCC code sequence is generated as follows based on the address value of each transmitter S. That is, at the transmitting station at address 1, a sequence is generated by sequentially arranging the values of 1 to 10. At the transmitting station at address 2, the second value 2 from the head of the previous address 1 series is set as the first value, and subsequent values are set every other value from the second value 2 of the address 1 series. It is taken out and it becomes 4,6,8,10. Subsequent values are the values 1, 3, 5, 7, and 9 remaining in the series of address 1.

In the transmitting station of address 3, the second value 4 from the head of the previous address 2 series is set to the first value, and the subsequent values are the second value 4 of the address 2 series. Are taken every other from, and become 8,1,5,9. Subsequent values are the values remaining in the series of address 2, 2, 6, 10, 3,
It becomes 7. Similarly, the value of the series of each transmitting station after address 4 is generated according to the address value.

[0032] With such a OCC code sequence, when starting from the same reference timing T ₀ as in the case of M-sequence pseudo-random number generated by the transmitter S is described above,
It is possible to generate the transmission timing of each transmitter S with little correlation with each other.

The code length of this OCC code sequence is also set to be extremely short as compared with the data collection period of the power consumption, and
The length is set to be short enough to make the size of the transmission data of each round small enough to fall within the allowable error range of the collected data. When the power consumption data is collected every month, the code length of the OCC code sequence is set to, for example, one and a half days (36 hours) as in the case of the M sequence described above. In the case of the above-described OCC code sequence, the code length is 55, and therefore, the time per unit code is about 39 minutes (= 36 × 60 ÷ 55).

Even in such a setting, the size of one transmission data from each consumer falls within the allowable error range of the collected data when viewed from the power consumption data collected in one month. . Therefore, even if a power failure occurs, the transmitter S stops and one transmission data is lost, there is no problem in collecting data for one month.

Next, a description will be given of a second embodiment in which the transmission timing generation method according to the present invention is applied to the above-described automatic meter reading system shown in FIG. FIG. 5 is a flowchart illustrating the transmission timing generation method according to the present embodiment.

First, the address value of each transmitter S provided in the watt hour meter WHM of each consumer is recognized (step 2).
01). Also in the present embodiment, there are ten transmitters S, and unique values of addresses 1 to 10 are assigned to each transmitter S. Next, a pseudo-random code sequence is generated with a value unique to each transmitter S as an initial value (step 20).
2). As the pseudo random code string, the first
The M sequence shown in FIG. 2B described in the embodiment of FIG.
There is an OCC sequence shown in (a), and each of these pseudo-random code sequences is generated as described above.

Next, the reference timing T at which the power of each transmitter S is turned on and the transmission control program starts.
_0, is added a long time specific fixed to each transmitter S (step 203). This fixed long time is a fixed long time peculiar to each transmitter that is not synchronized with the minimum unit of the code constituting the pseudo random code sequence. The minimum unit of the code constituting the M-sequence or the OCC sequence is a natural number of 1, and for a fixed long time, for example, a value A consisting of a decimal point which is not synchronized with the natural number 1 is selected.

The fixed long time is added as a value unique to each transmitter S. In the present embodiment, a fixed long time A is added to the transmitter S of address 1 as shown in FIG.
As shown in FIG. 3B, a fixed long time 2A is added to the transmitter S of the address 2 as shown in FIG. 4C, and a fixed long time 10A is added to the transmitter S of the address 10 as shown in FIG. Is done. Here, B represents the code length of the pseudo random code sequence. Thereafter, a long time from the shifted timing fixed from the reference timing T _0, the transmission timing of each transmitter S in the same manner as in the first embodiment goes generated (step 204).

In the present embodiment, the transmission timing of each transmitter S is generated from the timing shifted from the reference timing T ₀ by each fixed long time as described above, so that the transmission timing is generated for each code length of the pseudo random code sequence. Signal collision is prevented.

That is, although the correlation between the M-sequence code and the OCC-sequence code is small for each transmission, the transmission timing overlaps for each code length because the code lengths of the pseudo-random numbers match. For this reason, data is simultaneously transmitted from the plurality of transmitters S to the same line W, and the signals collide with each other, resulting in a loss of collected data for each code length. For example, in the case of an M-sequence code, FIG.
As shown in (c), a signal collision occurs between the transmitter S of address 1 and the transmitter S of address 8 for each code length 120,
In the case of the OCC sequence code, as shown in FIG. 4B, a signal collision occurs between the transmitter S of the address 1 and the transmitter S of the address 2 for each code length 55.

However, since the above-mentioned fixed long time period unique to each transmitter is added at the initial stage of generation of the transmission timing of each transmitter S as in the present embodiment, the end timing of one code length is determined for each transmitter S. Therefore, collision of signals generated for each code length is prevented.

Next, a description will be given of a third embodiment in which the transmission timing generation method according to the present invention is applied to the aforementioned automatic meter reading system shown in FIG. FIG. 7 is a flowchart illustrating the transmission timing generation method according to the present embodiment.

First, the address value of each transmitter S provided in the watt hour meter WHM of each consumer is recognized (step 3).
01). Next, a pseudo-random code sequence with a value unique to each transmitter S as an initial value is generated (step 302). As the pseudo-random code sequence, there are the M sequence shown in FIG. 2B described in the first embodiment and the OCC sequence shown in FIG. 4A, and these pseudo random code sequences are described above. Is generated as follows.

Next, based on the pseudo random code sequence,
The transmission timing of each transmitter S is generated in the same manner as in the first embodiment (step 303). However, if an external factor that occurs spontaneously occurs during the generation of the transmission timing, the next transmission timing is determined by the code constituting the pseudo-random code sequence, and the generation timing of the external factor is changed to the next transmission timing. Timing (step 304). Such external factors include, for example, a certain amount of change in the amount of power used by the watt hour meter WHM.

[0045] For example, while based on the pseudo-random code sequence as shown in FIG. 8 (a), the transmission timing _T 1 from the reference timing _{T 0, T 2, T 3} , are generating ..., the As shown in FIG. 7B, the external factor is the timing Ta.
In this case, the timing Ta at which the external factor has occurred is set as the next actual transmission timing as shown in FIG. Accordingly, the next transmission timing T ₄ shown in FIG.
Is advanced, and is set to timing Ta.

The transmission timing thereafter is determined again by the codes constituting the pseudo random code sequence (step 305). Therefore, earlier as shown in each actual transmission timing _{T 5, T 6, T 7} FIG accompanied in this transmission timing _{T 5} or later (c). Also, external factors when again generated in the timing Tb, as shown in FIG. 6 (b), the generation timing Tb is the actual transmission timing T ₈ of the next, as shown in FIG. (C).

As described above, when an external factor occurs, the next transmission timing is set as the external factor generation timing instead of determining the next transmission timing by the code constituting the pseudo random code sequence, thereby obtaining the external factor. The end timing of one code string of the pseudo-random code string assigned to the transmitter S to which is added is different from the end timing of one code string of the pseudo-random code string assigned to the other transmitters S.

As a result, even with the transmission timing generation method according to the present embodiment, the end timing of one code length is different for each transmitter S, so that collision of signals generated for each code length is prevented. Become.

In the transmission timing generation method according to the first embodiment, the code length of the pseudo-random code is reduced to such an extent that the size of one transmission data falls within the allowable error range of the collected data. Set as short as
Even if one transmission data is lost due to a power outage,
Data collection was not interrupted.

However, in the transmission timing generation method according to the first embodiment, as described in the second embodiment, each transmitter unique to each transmitter which is not synchronized with the minimum unit of the code constituting the pseudo-random code sequence is used. the timing shifted from only the reference timing T ₀ fixed long may generate the transmission timing of each transmitter S. According to this method, in addition to the effects of the first embodiment described above,
Further, there is an effect that signals are prevented from colliding for each code length of the pseudo random code sequence.

Further, in the transmission timing generation method according to the first embodiment, as described in the third embodiment, when an external factor occurs, the next transmission is performed by using a code constituting a pseudo random code sequence. Instead of determining the timing, the occurrence timing of the external factor may be set as the next transmission timing, and the subsequent transmission timing may be determined again by the codes constituting the pseudo random code sequence. According to this method, in addition to the effect of the first embodiment described above, further, an effect of preventing a signal from colliding for each code length of the pseudo-random code string is exerted.

Further, in the transmission timing generation method according to the first embodiment, a fixed long time is added at the initial stage of generation of the transmission timing as described in the second embodiment,
Moreover, as described in the third embodiment, the generation timing of the external factor may be set as the next generation timing. According to this method, in addition to the effect of the first embodiment described above, further, an effect of preventing a signal from colliding for each code length of the pseudo-random code string is exerted.

[0053]

As described above, according to the present invention, when the transmission timing of each transmitter is generated based on a pseudo-random code sequence starting from the same reference timing by using a value unique to each transmitter as an initial value, Transmission timing with little cross-correlation between transmitters can be generated. Moreover, if the code length of the pseudo-random code string is set short enough so that the size of one transmission data falls within the allowable error range of the collected data, a power failure occurs. Even if one transmission data is lost, there is no problem in data collection.

The code length is set to be short in this way,
When the transmission timing is generated irrespective of the change amount of the transmission data, the receiver frequently receives a signal from the transmitter regardless of the change amount of the transmission data. As a result, maintenance of the communication system is facilitated.

Further, the transmission timing of each transmitter is generated from the timing shifted from the reference timing by a fixed long time peculiar to each transmitter, so that the end timing of one pseudo random code sequence is different from each other. Become like For this reason, it is possible to prevent collision of signals generated for each code length.

Further, when an external factor occurs, instead of determining the next transmission timing by the code constituting the pseudo-random code sequence, the external factor occurrence timing is used as the next transmission timing, so that the external factor is reduced. One code string end timing of the pseudo random code string assigned to the added transmitter becomes different from one code string end timing of the pseudo random code string assigned to the other transmitters. Therefore, according to this method, it is possible to prevent collision of signals generated for each code length.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a transmission timing generation method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an M sequence generated by a transmission timing generation method according to the present embodiment.

FIG. 3 is a timing chart showing the transmission timing of each transmitter generated by the transmission timing generation method according to the embodiment.

FIG. 4 is a diagram showing an OCC sequence generated by a transmission timing generation method according to the present embodiment.

FIG. 5 is a flowchart illustrating a transmission timing generation method according to a second embodiment of the present invention.

FIG. 6 is a timing chart showing the transmission timing of each transmitter generated by the transmission timing generation method according to the second embodiment.

FIG. 7 is a flowchart illustrating a transmission timing generation method according to a third embodiment of the present invention.

FIG. 8 is a timing chart illustrating a transmission timing of a transmitter generated by a transmission timing generation method according to a third embodiment.

FIG. 9 is a block diagram showing a schematic configuration of a general automatic meter reading system.

[Explanation of Signs] WHM: Wattmeter T: Transformer C: Meter reading device R: Receiver S: Transmitter 1, 2, 3, 4 ... Shift register that constitutes M-sequence generator 5: M-sequence generator Constituting feedback tap (EXOR: exclusive OR circuit)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Fukuda 1 Higashi-Shinmachi, Higashi-ku, Nagoya City, Aichi Prefecture Inside Chubu Electric Power Co., Inc. In-house (72) Inventor Tetsuya Aoki 1 Kibukicho, Kasugai-shi, Aichi Prefecture Inside Chubu Seiki Co., Ltd. (72) Inventor Hiroshi Hasegawa 2-8-1 Tamagawa, Ota-ku, Tokyo Osaki Electric Industry Co., Ltd. 72) Inventor Katsuo Taniguchi 2-8-1 Tamagawa, Ota-ku, Tokyo F-term in the Technology Development Laboratory, Osaki Electric Industry Co., Ltd. 5K022 EE02 EE21 5K046 AA03 BB05 PP01 PS42 PS47 PS55 YY01 5K047 AA11 BB06 BB12 CC01 DD03 GG34 JJ08

Claims (6)

[Claims] 1. A communication system for performing one-way communication from a plurality of transmitters to one receiver and collecting data from the respective transmitters received by the receiver at regular intervals. Pseudo random with a short code length, starting from the same reference timing with the unique value set for the device as the initial value, and decreasing so that the size of one transmission data falls within the tolerance of the collected data. A transmission timing generation method for generating a code sequence and generating transmission timings of the respective transmitters based on the pseudo random code sequence. 2. A communication system for performing one-way communication from a plurality of transmitters to one receiver, wherein a pseudo-random code sequence starting from the same reference timing is used as an initial value with a unique value set for each transmitter. A transmission timing generation method for generating the transmission timing of each transmitter from a timing shifted from the reference timing by a fixed long time unique to each transmitter which is not synchronized with the minimum unit of the code constituting the pseudo random code sequence . 3. A communication system for performing one-way communication from a plurality of transmitters to one receiver, wherein a pseudo-random code sequence starting from the same reference timing is initialized with a unique value set for each of the transmitters as an initial value. Generate the transmission timing of each of the transmitters based on the pseudo-random code sequence, and when an external factor occurs, instead of determining the next transmission timing by the code constituting the pseudo-random code sequence. A transmission timing generation method in which the occurrence timing of the external factor is set as the next transmission timing, and the subsequent transmission timing is determined again by the codes constituting the pseudo random code sequence. 4. The transmission timing of each of the transmitters is generated from a timing shifted from the reference timing by a fixed long time unique to each of the transmitters that is not synchronized with a minimum unit of a code constituting the pseudo-random code sequence. 2. The transmission timing generation method according to 1. 5. When an external factor occurs, the next transmission timing is used as the next transmission timing instead of determining the next transmission timing by using a code constituting the pseudo-random code sequence. The transmission timing generation method according to claim 1 or 4, wherein the transmission timing is determined again by codes constituting the pseudo random code sequence. 6. The transmission timing generation method according to claim 1, wherein the pseudo random code sequence is an M sequence or an OCC code sequence.