JP4621993B2 - Wireless communication device - Google Patents

Description

The present invention relates to radio communications apparatus, particularly relates always to a radio communication equipment which enables stable wireless communication with less channel noise.

When performing wireless communication with a predetermined specific partner such as communication between a plurality of slave units and a master unit that controls the plurality of slave units in a wireless monitoring device, for example, a remote monitoring device , Transmission and reception are performed using the same radio frequency predetermined in advance.
However, when performing wireless communication, other devices may be performing wireless communication at the same frequency, or noise of the same frequency may be generated due to jamming waves generated from power cables, electronic devices, etc. Wireless communication is interrupted.

Therefore, when performing normal wireless communication, a carrier (or carrier frequency) sense is performed prior to wireless transmission / reception. However, when it is found by the carrier sense that another device is using the wireless channel, that is, transmission is attempted. When a radio wave with the same frequency as the radio wave to be detected is detected, it is possible to prevent the cross-talk by waiting for a call, performing carrier sense again after a certain period of time, and checking that the radio wave does not exist. It has been.
In such a case, if the signal cannot be transmitted / received, the carrier sense is repeated many times. However, if this carrier sense operation occurs frequently, not only the transmission / reception is delayed, but also the wireless device is, for example, a child in the remote monitoring system. When operating on a battery like a machine, it leads to a decrease in battery capacity, which is not preferable.

  Therefore, by performing carrier sense, the situation is grasped, and when there is a radio wave with the same frequency as the radio wave to be transmitted, it is switched to a frequency where there is no radio wave with the same frequency as the self or the existence probability of the radio wave is small. An air conditioning / hot water supply / water supply system including a main unit and a remote control has been proposed (see Patent Document 1).

In this air conditioning / hot water supply system, if it is found that there is a system that uses the same frequency in the vicinity of the device main unit, the remote control unit's response radio wave after receiving the radio wave from the remote control unit Instruction information for changing the transmission / reception frequency to a frequency f2 different from the current frequency f1 is attached.
The remote control unit receives this and returns it to the device body unit at a frequency f2 different from the current frequency f1. After knowing that there is a system using the same frequency in the vicinity, the device main unit repeats reception of the frequencies f1 and f2 alternately at a sufficiently short time interval with respect to one transmission time, and the radio wave of the frequency f2 Is captured, it is confirmed that it has the same ID code as itself, and a reply is made at the frequency f2.

However, in this conventional interference prevention method, after the apparatus body unit knows that there is a system using the same frequency in the vicinity, instruction information for changing to a frequency f2 different from the current frequency f1 is attached to the reply radio wave. However, since it is not immediately switched to the frequency f2, further carrier sense is performed for the reply, and the reply radio wave cannot be transmitted immediately, and the transmission timing may be delayed. Further, if this system is applied to a battery-driven communication device, there is a problem that the battery is consumed.
Further, when a radio wave having the same frequency as the frequency f1 is received, the frequency is switched regardless of the reception level of the radio wave. Therefore, the frequency is frequently switched, and similarly battery-driven communication equipment accelerates battery consumption. Occurs.

Therefore, the present applicant has previously reduced the number of times of carrier sense to reduce battery consumption of the wireless communication device and can change the carrier frequency in order to avoid radio interference. (See Patent Document 2).
When this radio communication device detects that the radio wave of the same frequency is carrier sensed, it determines whether the radio wave address ratio is equal to or greater than a predetermined ratio, and determines that the radio station address ratio does not reach a predetermined value. It is possible to determine whether or not the received signal level is equal to or higher than a predetermined level, and to convert to another frequency only when the ratio equal to or higher than the predetermined level is equal to or higher than a predetermined value, thereby preventing unnecessary frequency conversion.
Also, in the wireless communication device according to this proposal, carrier sense is performed, and the carrier is changed only when it is actually necessary according to the result, so that it is not possible to prevent unnecessary carrier conversion. it can. However, since the purpose of this wireless communication apparatus is to change the carrier based on the result of the carrier sense, the carrier has been changed, that is, this is used for individual reception error information when performing a reception operation. It is not taken into consideration. Therefore, the surrounding communication information obtained in the carrier sense cannot be used as information for setting the carrier of the system, for example. That is, the reception error information cannot be reflected in the carrier setting of the system.
JP 2002-295892 A Japanese Patent Application No. 2005-281835

  The present invention has been made in view of such a situation, and advances the wireless communication device previously proposed by the present applicant one step, collects and stores individual information resulting in a reception error, and uses the information. The carrier is set so that no reception error occurs, so that stable communication can always be performed, and the device (CPU) reacts to noise and other system carriers to shorten the battery life. Is to prevent.

[Action]
In the present invention, when performing a reception operation, a counter is provided for collecting individual information in which a reception error has occurred, and the factors causing the reception error are known from each individual information. Thereafter, the receiving operation and control (channel switching / stopping of the receiving operation) are performed.

The invention according to claim 1 is a first counter for counting the number of carrier senses , a means for comparing predetermined information in the received signal with preset information, a second counter for counting the number of coincidences or mismatches, In the wireless communication apparatus comprising: means for storing the count result of each counter; and control means for determining whether communication is appropriate or inappropriate based on a ratio between the carrier sense count and the match / mismatch count. Is a counter that counts the number of preamble pattern mismatches when the Manchester encoding pattern of the received signal matches during counting of the number of carrier senses, wherein the control means sets the number of carrier senses to Y, and the preamble at that time When the number of pattern mismatches is Z, the carrier is preset when Z / Y exceeds the specified value. Wherein the switch has in addition to the carrier.
The invention according to claim 2 is a first counter for counting the number of carrier senses , a means for comparing predetermined information in the received signal with preset information, a second counter for counting the number of coincidences or mismatches, In the wireless communication apparatus comprising: means for storing the count result of each counter; and control means for determining whether communication is appropriate or inappropriate based on a ratio between the carrier sense count and the match / mismatch count. Is a counter that counts the number of times that the Manchester coding pattern of the received signal coincides during the carrier sense count and the header pattern does not match when the preamble pattern matches. Y is the number of times, W is the number of mismatches of the header pattern at that time, and W / Y is predetermined When the value is exceeded, the carrier is switched to another preset carrier .

According to the present invention, stable wireless communication can always be performed with a channel with less noise, and battery operation can be suppressed by reducing CPU operation due to noise or other system carrier reception.
In addition, during maintenance, if the battery life falls below the expected time, the influence of external noise can be determined from LOG (database change history, etc.) as a cause identification means, and avoidance measures can be taken in advance. it can.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an RF (Radio Frequency) circuit unit 10 according to an embodiment of a slave that is a wireless communication apparatus 1 of the present invention.
The RF circuit unit 10 includes an amplifier 12 that amplifies the signal from the antenna 11, a demodulation circuit 13 that demodulates the amplified signal, a reception data comparison circuit 14 that extracts received data from the demodulated signal and compares it with preset data, and a demodulator Carrier sense timing generation circuit 15 for generating carrier sense timing based on the received signal, counters 16a to 16d for counting various data (to be described later) of the received signal at the generation timing of carrier sense timing generation circuit 15, modulation circuit 17, modulation A synthesizer 18 for obtaining a stable frequency from the circuit 17, an amplifier 19 for amplifying a signal from the synthesizer 18, and a CPU interface (I for connection with a microcomputer 30 arranged outside the RF circuit 10. / F) 20. The microcomputer 30 includes a CPU 30a, a ROM 30b, and a RAM 30c. The control unit of the wireless communication apparatus supplies the setting data to the comparison circuit 14 and performs calculations and determinations based on the count information of each counter. Take control.

Here, the counter includes the following four counters.
(1) A counter 16a that counts the number of times carrier sense is executed in intermittent reception at a fixed period.
(2) A counter 16b that counts the number of times a mismatch with the Manchester coding pattern (possibility of data corruption) is detected after recognizing the presence of a carrier by carrier sense.
(3) After recognizing the presence of a carrier by carrier sense, it detects the coincidence with the Manchester coding pattern (no possibility of data destruction), and transmits a preamble pattern (a pattern for wireless connection from a wireless terminal, transmitted from a transmitting terminal) Counter 16c that counts the number of times that a mismatch of a fixed pattern) is detected so that the received signal can be accurately received by the receiving terminal.
(4) After recognizing the presence of a carrier by carrier sense, coincidence with the Manchester encoded pattern is detected, and also coincidence of the preamble pattern is detected, and then the header pattern (a pattern indicating an address, which can be changed by a dip switch, for example) ) Is a counter 16d that counts the number of times of mismatch.

  In the above configuration, when carrier sensing is performed, a signal received by the antenna 11 is demodulated by the demodulator 13d, and the demodulated signal is compared with a plurality of data set in advance by the reception data comparison circuit 14. Each of the counters 16a to 16d operates in synchronization with the reception data comparison circuit output by a timing signal from the carrier sense timing generation circuit 15 controlled by the output from the demodulation circuit 13, and outputs each output from the comparison circuit. From a certain comparison result, a target numerical value, that is, each piece of information assigned to each counter is picked up and counted, and the count value is transmitted to the microcomputer 30 of the wireless communication device as a slave unit. Control to do.

  That is, this wireless communication apparatus has the four counters independently for each carrier, and the microcomputer as a control apparatus performs the following control based on the count information from the four counters for each carrier. Hereinafter, the processing procedure will be described with reference to the drawings.

FIG. 2 is a flowchart showing the operation procedure of the first counter 16a.
The first counter 16a counts the number (Y) of carrier sensing performed in intermittent reception at a constant period (S101), and the microcomputer 30 stores the count value in, for example, the RAM 30c as storage means (S102). ).

FIG. 3 is a flowchart showing an operation procedure of the second counter 16b.
After the second counter 16b recognizes the presence of a carrier by carrier sense (S201, YES), the received data comparison circuit 14 detects a mismatch with the Manchester encoding pattern of the carrier (S202, YES). The microcomputer 30 counts the number of times (X) (S203). For example, the microcomputer 30 recognizes the presence of a carrier by carrier sense, and then detects the number of mismatches with the Manchester coding pattern / number of carrier senses (X / Y). (S204), and when the ratio (X / Y) is 70% or more (S205, YES), it is determined that there is radiation noise from other devices or other systems that are not Manchester encoded in the vicinity. Then, the carrier shifts to another preset wireless channel (S206).

  Further, the microcomputer 30 recognizes that there is a carrier by carrier sense of all the wireless channels available in the system, and then the ratio of the number of times of detecting mismatch with the Manchester coding pattern / the number of times of carrier sense becomes 100%. (S207, YES), it is determined that all radio channels are crushed by radiation noise from other devices, and the carrier detection cycle is increased to reduce the power consumption, or The transmission / reception operation is stopped (S208).

FIG. 4 is a flowchart showing an operation procedure of the third counter 16c.
The counter 16c, after recognizing the presence of a carrier by carrier sense (S301, YES), detects a match with the Manchester encoded pattern (S302, YES), and when it detects a mismatch with the preamble pattern (S303, YES) The microcomputer 30 counts the number of times (Z) (S304) and, for example, recognizes the presence of a carrier by carrier sense, and then detects a match with the Manchester encoded pattern and detects a mismatch with the preamble pattern. When the ratio (Z) / carrier sense count (Y) exceeds 70% (S305, YES), it is determined that another system having Manchester encoding exists in the vicinity. Then, the carrier shifts to another predetermined radio channel (S306).

FIG. 5 is a flowchart showing an operation procedure of the fourth counter 16d.
The counter 16d detects the presence of a carrier by carrier sense (S401, YES), detects a match with the Manchester encoded pattern (S402, YES), detects a match with the preamble pattern (S403, YES), When the header patterns do not match (S404, YES), the number of times (W) is counted (S405). The microcomputer 30 detects, for example, the presence of a carrier by carrier sense, detects a match with the Manchester encoded pattern, detects a match with the preamble pattern, and then the number of times the header pattern does not match (W) / If the number of carrier senses (Y) is calculated and the ratio (W / Y) exceeds 70% (S406, YES), it is determined that the same system exists in the vicinity, and other previously determined The carrier shifts to the radio channel (S407).

  As described above, all counter information counted by each counter is stored in a memory such as the RAM 30c. As a result, it is possible to determine the ambient noise status during maintenance and use it for changing the device installation location or re-designating the wireless channel.

In the above description, the wireless communication device is taken as an example of a slave unit of a remote monitoring system, and based on the counter information installed in the slave unit, the microcomputer of the slave unit determines the carrier change and executes the operation. As described above, the above four counter information may be transmitted to a higher-level device (parent device, management server) via a control channel, and the above operation may be performed based on a determination / instruction from the higher-level device.
It is also possible to periodically transfer counter information to the center server, determine the status of equipment peripheral noise, and change the radio channel using commands from the center.

As described above, in the radio communication equipment according to the present invention, the can know the contents of the surrounding communication error from the count information for each counter, also, by storing the count information, the Since the status of communication errors in the area can be grasped, by referring to these, appropriate carrier setting can be performed when setting the carrier of the communication system at the time of maintenance or the like.

It is a block diagram of the radio | wireless communication apparatus of this invention. It is a flowchart explaining the process of a 1st counter. It is a flowchart explaining the process of a 2nd counter. It is a flowchart explaining the process of a 3rd counter. It is a flowchart explaining the process of a 4th counter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... RF circuit part, 11 ... Antenna, 12 ... Amplifier, 13 ... Demodulation circuit, 14 ... Comparison circuit, 15 ... Carrier sense timing generation circuit, 16 (16a-16d) ... Counter, 17 ... Modulation circuit, 18 ... Synthesizer, 19 ... Amplifier, 20 ... CPU interface, 30 ... Microcomputer.

Claims (2)

A first counter for counting the number of carrier senses, a means for comparing predetermined information in the received signal with preset information, a second counter for counting the number of coincidences or mismatches, and the count result of each counter means for storing, from the ratio of the match or mismatch count and the carrier sense times, the radio communications apparatus having a control means for determining a suitable or unsuitable for communication,
The second counter is a counter that counts the number of mismatches of the preamble pattern when the Manchester encoding pattern of the received signal matches during counting of the number of carrier senses,
The control means is characterized in that the number of times of carrier sense is Y and the number of mismatches of the preamble pattern at that time is Z, and when Z / Y exceeds a predetermined value, the carrier is switched to another preset carrier. Wireless communication device . A first counter for counting the number of carrier senses, a means for comparing predetermined information in the received signal with preset information, a second counter for counting the number of coincidences or mismatches, and the count result of each counter In a wireless communication apparatus comprising a storage means and a control means for determining whether communication is appropriate or inappropriate from a ratio between the carrier sense count and the match or mismatch count,
It said second counter is a counter for counting the number of times that the header pattern has become mismatched when Manchester coding pattern of a received signal in a carrier sense count during the counting match and the preamble pattern is matched,
The control means is characterized in that the number of times of carrier sense is Y, the number of mismatches of the header pattern at that time is W, and when W / Y exceeds a predetermined value, the carrier is switched to another preset carrier. Wireless communication device.

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