JP7724692B2 - wireless device - Google Patents

Description

This disclosure relates to a wireless device that supports multiple communication methods and performs receive diversity.

Wi-SUN (Wireless Smart Utility Network) is a wireless communication standard used in the 920 MHz band, known as specified low-power radio. Specific low-power radio, such as Wi-SUN, is used for communication with smart meters, for example. Smart meters use receive diversity, which uses multiple antennas to remove noise from the received signal, enabling stable medium-range communication.

Receive diversity includes antenna selection, which prioritizes signals from antennas with better radio wave conditions, and maximum ratio combining, which combines signals received by multiple antennas. Receive diversity is primarily used in 920 MHz mesh communications, such as communications between smart meters or wireless communications between smart meters and concentrators.

Smart meters equipped with LTE (Long Term Evolution) transceivers and compatible with 1:N wireless systems have a problem in that when wireless communication is performed simultaneously using the 920 MHz mesh system and LTE, both systems are unable to send and receive wireless signals stably. This problem is not limited to smart meters, but occurs in wireless devices that support multiple wireless systems as well.

Patent Document 1 is a document disclosing prior art for wireless devices that use multiple wireless methods. Patent Document 1 discloses technology that calculates the frequency of intermodulation waves generated by radio waves transmitted by an LTE radio unit and a Wi-Fi radio unit, and when the calculated frequency of the intermodulation waves overlaps with the reception frequency of the LTE radio unit, switches the operation of at least one of the LTE radio unit and the Wi-Fi radio unit from normal mode to low-interference mode.

The radio described in Patent Document 1 comprises an LTE radio unit and a wireless LAN unit. It is configured with two LTE antennas and one wireless LAN antenna. Because LTE and wireless LAN use different frequencies, intermodulation waves (IM3) are generated when the LTE radio unit and wireless LAN unit transmit simultaneously. When IM3 occurs in the LTE reception band, the LTE reception sensitivity deteriorates. The degree of deterioration differs depending on whether the antenna used for LTE reception is a low-interference antenna or a non-low-interference antenna. Patent Document 1 discloses a method for addressing the deterioration of LTE reception sensitivity by calculating the frequency at which IM3 occurs in the control unit, and, if IM3 is included in the LTE reception band, fixing the LTE antenna from diversity to a low-interference antenna, thereby achieving stable communications.

WO 2016/185871 (pages 17-19, Figures 1, 5-7)

The technology in Patent Document 1 addresses the degradation of reception sensitivity due to IM3 that occurs when a wireless device capable of using multiple wireless methods simultaneously transmits using different wireless methods, but it does not address the problem of degradation of reception sensitivity for other wireless methods when switching antennas for one wireless method.

This disclosure was made in consideration of the above-mentioned problems, and aims to reduce the impact of receive diversity in one wireless system on the receive sensitivity of other wireless systems in a wireless device that can use multiple wireless systems.

The wireless device of the present disclosure includes a first wireless unit that performs wireless communication using a first wireless method, a second wireless unit that performs wireless communication using a second wireless method, a plurality of first antennas that are used only for the wireless communication of the first wireless unit, a second antenna that is used only for the wireless communication of the second wireless unit, and a control unit that controls the first wireless unit and the second wireless unit , and the control unit stops receive diversity operation by fixing the first antenna used as a receive antenna for the wireless communication of the first wireless unit during a communication interval using the second wireless method.

The wireless device disclosed herein can suppress the adverse effects of receive diversity in the first wireless unit on the receive sensitivity in the second wireless unit.

1 is a configuration diagram of a wireless system according to a first embodiment; FIG. 2 is a configuration diagram of a first wireless device according to the first embodiment. 5 is a flowchart showing an operation of the first wireless device according to the first embodiment; FIG. 10 is a configuration diagram of a first wireless device according to a second embodiment. 10 is a flowchart illustrating an operation of the first wireless device according to the second embodiment. FIG. 11 is a configuration diagram of a first wireless device according to a third embodiment. FIG. 2 is a diagram illustrating a hardware configuration of a first wireless device. FIG. 2 is a diagram illustrating a hardware configuration of a first wireless device.

The wireless device of the present disclosure includes two or more wireless units that receive radio waves using a plurality of different wireless methods. In the following embodiments, the number of wireless units included in the wireless device is assumed to be two, and these will be referred to as the first wireless unit and the second wireless unit. In the following embodiments, the first wireless unit that performs receive diversity operation will be described as a specific low-power wireless unit, and the second wireless unit that avoids degradation of receive sensitivity will be described as an LTE wireless unit. However, the wireless methods used in the technology of the present disclosure are not limited to this.

<A. First Embodiment>
The applicant confirmed that the LTE receiving sensitivity deteriorated in a wireless device that supports both specified low-power radio and LTE. Since the LTE receiving sensitivity did not deteriorate when the antenna was fixed without operating the receive diversity in the specified low-power radio, it is presumed that the fluctuations in the electromagnetic field distribution caused by the antenna switching operation in the receive diversity operation of the specified low-power radio affect the LTE antenna characteristics and thus the LTE receiving sensitivity.

<A-1. Configuration>
1 is a configuration diagram of a wireless system 101 according to the first embodiment. The wireless system 101 includes a first wireless device 1A, a plurality of second wireless devices 2, and an aggregation device 3. The first wireless device 1A and the plurality of second wireless devices 2 are, for example, smart meters.

The first wireless device 1A comprises an LTE wireless unit 11 and a specified low-power wireless unit 12. The specified low-power wireless unit 12 performs specified low-power wireless communication with multiple second wireless devices 2. The LTE wireless unit 11 performs LTE wireless data communication with an aggregation device 3, which is a higher-level device of the first wireless device 1. In this way, the first wireless device 1A supports multiple wireless methods.

The second wireless device 2 has a specified low-power wireless unit 21 but does not have an LTE wireless unit. In other words, the second wireless device 2 is compatible only with the specified low-power wireless system. The specified low-power wireless unit 21 performs specified low-power wireless communication with the first wireless device 1 and other second wireless devices 2.

In Figure 1, the solid bidirectional arrows represent specific low-power wireless communication, and the dashed bidirectional arrows represent LTE wireless communication.

Figure 2 is a block diagram showing the detailed configuration of the first wireless device 1A. In addition to the LTE wireless unit 11 and specified low-power wireless unit 12 described in Figure 1, the first wireless device 1A also includes a control unit 13, a first RF switch 14, two antennas 15-1 and 15-2 for specified low-power wireless, and an antenna 16 for LTE.

The control unit 13 controls the LTE radio unit 11 and the specified low-power radio unit 12. The control unit 13 sets the specified low-power radio unit 12 to a transmission state in order to periodically transmit data via the specified low-power radio. The control unit 13 also controls the first RF switch 14 to transmit data from antennas 15-1 and 15-2.

The first RF switch 14 sets antennas 15-1 and 15-2 to a receiving state when data is not being transmitted, and receives notifications from the second wireless device 2 and other devices via antennas 15-1 and 15-2.

The specific low-power radio unit 12 demodulates notifications received by antennas 15-1 and 15-2 from the second radio device 2 and other devices, and requests the control unit 13 to collect the data.

In response to a request from the specific low-power radio unit 12, the control unit 13 collects data such as meter values or fault details, and sends the collected data to the specific low-power radio unit 12 as a response. The control unit 13 also controls the first RF switch 14, which controls transmission from the antenna 15. In this way, the data collected by the control unit 13 is transmitted from the antenna 15.

The control unit 13 also sets the LTE radio unit 11 to a transmission state for data transmission via LTE. This causes transmission from the antenna 16. The LTE radio unit 11 sets the antenna 16 to a reception state except when transmitting data. The LTE radio unit 11 periodically checks reception. When the antenna 16 receives a notification from a higher-level device such as the aggregation device 3, the LTE radio unit 11 demodulates the received data and makes a request to the control unit 13. When the control unit 13 receives a request from the LTE radio unit 11, it sends data such as meter values or fault details collected from the second radio device 2 along with a response to the LTE radio unit 11. The data is then transmitted from the antenna 16.

Normally, antennas 15-1 and 15-2 for specified low-power radio signals are in a receiving state except when transmitting. The control unit 13 selects one of the two antennas 15-1 and 15-2 as the antenna to be used for receiving specified low-power radio signals (hereinafter also referred to as the "receiving antenna"). Normally, the control unit 13 selects the antenna with the highest received signal strength (Received Signal Strength Indicator: RSSI) as the receiving antenna. The control unit 13 outputs a signal specifying the receiving antenna to the first RF switch 14 as a first antenna selection signal S1. For example, if the first antenna selection signal S1 is High, it indicates that antenna 15-1 is the receiving antenna, and if the first antenna selection signal S1 is Low, it indicates that antenna 15-2 is the receiving antenna.

Based on the first antenna selection signal S1 received from the control unit 13, the first RF switch 14 switches the output to the receiving antenna to High and the output to the other antennas to Low. The first RF switch 14 receives a radio signal from the receiving antenna and outputs it to the specified low-power radio unit 12. The specified low-power radio unit 12 outputs the radio signal received from the first RF switch 14 to the control unit 13.

During receive diversity operation, the selection of the receive antenna by the control unit 13 changes dynamically.

The LTE radio unit 11 also transmits and receives radio signals to and from other radio devices, namely the aggregation device 3, via the antenna 16. The LTE radio unit 11 is aware of the LTE communication interval in advance. The LTE radio unit 11 inputs an LTE communication detection signal indicating the LTE communication interval to the control unit 13. When the LTE communication detection signal is input from the LTE radio unit 11, the control unit 13 detects the LTE communication interval. For example, the control unit 13 determines that if the LTE communication detection signal is High, it is an LTE communication interval, and if it is Low, it is an LTE non-communication interval.

<A-2. Operation>
FIG. 3 is a flowchart showing the operation of the first wireless device 1A in the first embodiment.

First, the control unit 13 detects the start of the LTE communication section using an LTE communication detection signal (step S101).

Next, the control unit 13 measures the RSSI of antennas 15-1 and 15-2 during the trial confirmation period and selects the antenna with the larger RSSI as the receiving antenna. After the trial confirmation period, the control unit 13 fixes the first antenna selection signal S1 to either High or Low depending on the result of the receiving antenna selection. The control unit 13 then stops outputting the first antenna selection signal S1 to the first RF switch 14, thereby stopping receive diversity for the specified low-power radio (step S102).

Next, the control unit 13 detects the end of the LTE communication section from the LTE communication detection signal (step S103) in the same manner as detecting the start of the LTE communication section (step S101).

Then, the control unit 13 releases the level of the first antenna selection signal S1 and resumes outputting the first antenna selection signal S1 to the first RF switch 14. This releases the stop of receive diversity for the specified low-power radio (step S104).

<A-3. Effects>
A first wireless device 1A, which is a wireless device according to the first embodiment, includes a specified low-power wireless unit 12, which is a first wireless unit that performs wireless communication using a specified low-power wireless system, which is a first wireless method; an LTE wireless unit 11, which is a second wireless unit that performs wireless communication using LTE, which is a second wireless method; and a control unit 13 that controls the specified low-power wireless unit 12 and the LTE wireless unit 11. The control unit 13 stops receive diversity operation for the specified low-power wireless unit 12 during a communication interval of the LTE wireless unit 11 using LTE. Therefore, according to the first wireless device 1A, the receive diversity operation of the specified low-power wireless unit 12 does not affect the antenna characteristics of the LTE wireless unit 11 during operation, and degradation of the receive sensitivity of the LTE wireless unit 11 is suppressed.

In the first wireless device 1A of embodiment 1, the control unit 13 extracts a signal indicating the LTE communication interval from the LTE wireless unit 11. Therefore, according to the first wireless device 1A, the control unit 13 can determine the LTE communication interval from the signal received by the LTE wireless unit 11 via LTE, and can cause the specified low-power wireless unit 12 to stop receive diversity operation during the LTE communication interval.

<B. Second Embodiment>
<B-1. Configuration>
4 is a block diagram showing the configuration of a first radio device 1B according to embodiment 2. The configuration of a radio system including the first radio device 1B is as shown in FIG.

The first wireless device 1B differs from the first wireless device 1A of the first embodiment in that the control unit 13 includes a timer 131. In the first wireless device 1A of the first embodiment, the control unit 13 detects the LTE communication interval using the LTE communication detection signal received from the LTE wireless unit 11. In contrast, in the first wireless device 1B, the control unit 13 detects the LTE communication interval based on the LTE DRX (Discontinuous Reception) cycle and PTW (Paging Time Window), that is, the communication cycle and communication interval defined by the wireless system standard.

DRX is an LTE technology that reduces power consumption by periodically conducting intermittent communication. The period between one communication interval and the next is called the DRX period. DRX paging occurs every 1.28 seconds. In response to demands for lower power consumption, eDRX, which significantly extends the period for intermittent communication, is also becoming more widespread on the market.

A device operating in eDRX attempts to receive paging (calls from the base station) according to the DRX cycle only within a periodic interval called the PTW.

For this reason, in the first wireless device 1B, the control unit 13 reduces the frequency with which receive diversity operation is stopped by suspending receive diversity operation only during the PTW period in which the LTE wireless unit 11 receives paging.

The control unit 13 is equipped with a timer 131 for the LTE communication section, and keeps track of the LTE communication section by updating the opportunities to receive paging as needed.

The control unit 13, having identified the LTE communication section using the timer 131, avoids degradation of LTE reception sensitivity by suspending the operation of receive diversity for specified low-power radio signals during the LTE communication section, as in embodiment 1.

<B-2. Operation＞
FIG. 5 is a flowchart showing the operation of the first radio device 1B according to the second embodiment.

The LTE radio unit 11 outputs a paging notification S3 to the control unit 13 every 1.28 seconds in the case of DRX, and every few minutes to tens of minutes in the case of eDRX, based on its implementation specifications or setting values. When the control unit 13 receives a paging notification S3 from the LTE radio unit 11, it initializes the timer 131 (step S201).

Based on the value of this timer 131, the control unit 13 determines the LTE communication section and, taking into account guard times and other factors, determines the timing to stop receive diversity for the specified low-power radio and the timing to resume receive diversity for the specified low-power radio. The timer 131 is updated every 1.28 seconds in the case of DRX, and every few minutes to tens of minutes in the case of eDRX. The control unit 13 determines the timing to stop receive diversity and the timing to resume receive diversity for the specified low-power radio based on the guard time calculated based on the switching time of the first RF switch 14 and the transmission/reception switching time of the specified low-power radio unit 12.

Then, based on the timing to stop receive diversity for the specified low-power radio determined by the value of timer 131, control unit 13 measures the RSSI of antennas 15-1 and 15-2 during the trial confirmation period and selects the antenna with the larger RSSI as the receive antenna. After the trial confirmation period, control unit 13 fixes the first antenna selection signal S1 to either High or Low depending on the result of the receive antenna selection. Thereafter, control unit 13 stops outputting the first antenna selection signal S1 to first RF switch 14, thereby stopping receive diversity for the specified low-power radio (step S202).

Next, the control unit 13 detects the timing to release the receive diversity stop for the specified low-power radio, i.e., the end of the LTE communication interval, based on the value of the timer 131 (step S203). The control unit 13 then releases the level of the first antenna selection signal S1 and resumes outputting the first antenna selection signal S1 to the first RF switch 14. This releases the receive diversity stop for the specified low-power radio (step S204).

<B-3. Effects>
According to the first wireless device 1B of the second embodiment, the second wireless system is LTE, and the control unit 13 includes a timer 131 that is initialized upon receiving a paging notification from the LTE wireless unit 11, which is the second wireless unit, and based on the value of the timer 131, stops the receive diversity operation of the specified low-power wireless unit 12, which is the first wireless unit, only during the PTW interval in which the LTE wireless unit 11 receives the paging. Therefore, according to the first wireless device 1A, the receive diversity operation of the specified low-power wireless unit 12 does not affect the antenna characteristics of the LTE wireless unit 11 in operation, and deterioration of the receive sensitivity of the LTE wireless unit 11 is suppressed. Furthermore, because the receive diversity operation is stopped only during the PTW interval in the LTE communication interval, the frequency with which the receive diversity operation is stopped is reduced.

<C. Third Embodiment>
The first wireless devices 1A and 1B of the first and second embodiments avoid degradation of LTE reception sensitivity by stopping the reception diversity operation of the specified low-power radio during the LTE communication interval. The first wireless device 1C of the third embodiment suppresses degradation of LTE reception sensitivity by changing the combination of the specified low-power radio and the LTE antenna during the LTE communication interval.

<C-1. Configuration>
6 is a block diagram showing the configuration of a first radio device 1C according to embodiment 3. The configuration of the radio system including the first radio device 1C is as shown in FIG.

The first wireless device 1C differs from the first wireless device 1A of the first embodiment in that it has one antenna 15 dedicated to specified low-power radio, no antenna dedicated to LTE, and multiple antennas 16-1 and 16-2 shared by specified low-power radio and LTE.

The first wireless device 1C also includes a second RF switch 17 that is controlled by the LTE wireless unit 11 and individually switches antennas 16-1 and 16-2 between connecting to the LTE wireless unit 11 and connecting to the specified low-power wireless unit 12 via the first RF switch 14. Antennas 16-1 and 16-2 become LTE antennas when connected to the LTE wireless unit 11, and become antennas for specified low-power wireless when connected to the specified low-power wireless unit 12. The rest of the configuration of the first wireless device 1C is the same as that of the first wireless device 1A.

<C-2. Operation＞
First, the operation of the first wireless device 1C regarding the specified low-power wireless communication will be described.

The control unit 13 sets the specified low-power radio unit 12 to a transmission state for periodic data transmission. The control unit 13 also sends a first antenna selection signal S1 to the first RF switch 14 and a second antenna selection signal S2 to the second RF switch 17. The first RF switch 14 selects antenna 15 as the antenna for the specified low-power radio using the first antenna selection signal S1. The second RF switch 17 selects either antenna 16-1 or 16-2 as the antenna for the specified low-power radio using the second antenna selection signal S2. The specified low-power radio unit 12 then transmits data using the antenna selected for the specified low-power radio.

The specified low-power radio unit 12 sets the antennas selected for specified low-power radio use to a receiving state except when transmitting. When the specified low-power radio unit 12 receives a notification from the second radio device 2 via these antennas, it demodulates the notification and sends a request to the control unit 13. Based on the request from the specified low-power radio unit 12, the control unit 13 collects data such as meter values or fault details, and sends the collected data to the specified low-power radio unit 12 as a response. The control unit 13 also controls the first RF switch 14 and second RF switch 17 to control antenna transmission.

Next, the operation of the first wireless device 1C regarding LTE communication will be described.

The control unit 13 sets the LTE radio unit 11 to a transmission state for data transmission. The control unit 13 also sends a second antenna selection signal S2 to the second RF switch 17. The second RF switch 17 selects either antenna 16-1 or 16-2 as the antenna for LTE based on the second antenna selection signal S2. The LTE radio unit 11 then transmits data using either antenna 16-1 or 16-2 selected for LTE.

The LTE radio unit 11 sets either of the antennas 16-1 and 16-2 selected for LTE to a receiving state except when transmitting data. The LTE radio unit 11 periodically checks reception. When either of the antennas 16-1 and 16-2 selected for LTE receives a notification from a higher-level device such as the aggregation device 3, the LTE radio unit 11 demodulates the received data and makes a request to the control unit 13. When the control unit 13 receives a request from the LTE radio unit 11, it sends data such as meter values or fault details collected from the second wireless device 2 along with a response to the LTE radio unit 11. The data is then transmitted from either of the antennas 16-1 and 16-2 selected for LTE.

The control unit 13 measures in advance the impact of LTE reception sensitivity degradation due to receive diversity operation of specified low-power radio for the following two antenna combinations, and determines which combination has the least impact of LTE reception sensitivity degradation.

Pattern 1: Antennas 15 and 16-1 are for specified low-power radio, and antenna 16-2 is for LTE Pattern 2: Antenna 15 is for specified low-power radio, and antennas 16-1 and 16-2 are for LTE Hereinafter, it is assumed that the impact of LTE reception sensitivity degradation is smaller in Pattern 2 than in Pattern 1. During the trial confirmation period, the control unit 13 uses the first antenna selection signal S1 to select antenna 15 for specified low-power radio, and uses the second antenna selection signal S2 to select antenna 16-2 for specified low-power radio, and antenna 16-1 for LTE, so as to achieve the antenna combination of Pattern 2.

The impact that receive diversity operation of specified low-power radios has on LTE receive sensitivity degradation also depends on the characteristics and placement of each antenna.

In the antenna configuration shown in Figure 6, the impact of LTE reception sensitivity degradation can be reduced by changing the combination of specified low-power radio and LTE antennas.

As described above, the timing when the control unit 13 switches to the antenna combination of pattern 2, which has little impact on LTE reception sensitivity degradation, is during the LTE communication interval. The antenna combination is not fixed to pattern 2 outside the LTE communication interval. This is because, for example, if the performance of antenna 16-1 is better than the performance of antenna 16-1 in a specified low-power radio band, the antenna combination of pattern 1 can be selected outside the LTE communication interval, prioritizing the specified low-power radio performance.

<C-3. Effects>
A first wireless device 1C, which is a wireless device according to a third embodiment, includes three or more antennas 5, 6-1, and 6-2. A control unit 13 switches between whether each of the antennas is connected to a specified low-power wireless unit 12, which is a first wireless unit, and used for wireless communication using the specified low-power wireless method, or whether it is connected to an LTE wireless unit 11, which is a second wireless unit, and used for wireless communication using the LTE method, during an LTE communication interval and at other times. Therefore, during an LTE communication interval, the first wireless device 1C can suppress degradation of LTE reception sensitivity by employing a combination of antennas that is less affected by degradation of LTE reception sensitivity due to reception diversity operation of the specified low-power wireless method.

D. Hardware Configuration
The LTE radio unit 11, specified low-power radio unit 12, and control unit 13 in the first radio device 1A-1C described in Embodiments 1-3 are realized by a processing circuit 81 shown in FIG. 7. That is, the processing circuit 81 includes the LTE radio unit 11, specified low-power radio unit 12, and control unit 13 (hereinafter referred to as the LTE radio unit 11, etc.). Dedicated hardware may be applied to the processing circuit 81, or a processor that executes a program stored in memory may be applied. The processor may be, for example, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a DSP (Digital Signal Processor), etc.

When the processing circuit 81 is dedicated hardware, the processing circuit 81 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these. Each function of a unit such as ~ unit may be realized by multiple processing circuits 81, or the functions of each unit may be combined and realized by a single processing circuit.

When the processing circuit 81 is a processor, the functions of the LTE radio unit 11 and other components are realized by a combination of software (software, firmware, or software and firmware). Software is written as a program and stored in memory. As shown in FIG. 8 , the processor 82 applied to the processing circuit 81 realizes the functions of each component by reading and executing a program stored in memory 83. In other words, this program can be said to cause a computer to execute the procedures or methods of the LTE radio unit 11 and other components. Here, the memory 83 may be, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory), a hard disk drive (HDD), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, a DVD (Digital Versatile Disk) and its drive device, or any storage medium that will be used in the future.

Above, we have described a configuration in which the functions of the LTE radio unit 11, etc. are realized either by hardware or software, etc. However, this is not limited to this, and a configuration in which part of the LTE radio unit 11, etc. is realized by dedicated hardware and another part is realized by software, etc. For example, the functions of the LTE radio unit 11 can be realized by a processing circuit as dedicated hardware, and the other functions can be realized by the processing circuit 81 as processor 82 reading and executing programs stored in memory 83.

In addition, it is possible to freely combine each embodiment, and to modify or omit each embodiment as appropriate.

1A, 1B, 1C: First wireless device, 2: Second wireless device, 3: Aggregation device, 5: Antenna, 11: LTE wireless unit, 12: Specified low-power wireless unit, 13: Control unit, 14: First RF switch, 15, 15-1, 15-2, 16, 16-1, 16-2: Antenna, 17: Second RF switch, 21: Specified low-power wireless unit, 81: Processing circuit, 82: Processor, 83: Memory, 101: Wireless system, 131: Timer, S1: First antenna selection signal, S2: Second antenna selection signal.

Claims (6)

a first wireless unit that performs wireless communication using a first wireless method;
a second wireless unit that performs wireless communication using a second wireless system;
a plurality of first antennas used only for wireless communication by the first wireless unit;
a second antenna used only for wireless communication by the second wireless unit;
a control unit that controls the first radio unit and the second radio unit,
the control unit stops a receive diversity operation by fixing a first antenna used as a receive antenna for wireless communication of the first wireless unit during a communication interval according to the second wireless system.
Radio equipment. the first wireless system is a specified low-power wireless system,
the second wireless system is LTE;
10. The wireless device of claim 1. the control unit acquires a signal indicating a communication interval according to the second wireless system from the second wireless unit.
3. The wireless device according to claim 1. the second wireless system is LTE,
the control unit includes a timer that is initialized when a paging notification is received from the second wireless unit, and stops the receive diversity operation of the first wireless unit based on a value of the timer.
3. The wireless device according to claim 1. a first wireless unit that performs wireless communication using a first wireless method;
a second wireless unit that performs wireless communication using a second wireless system;
a control unit that controls the first radio unit and the second radio unit,
the second wireless system is LTE,
the control unit includes a timer that is initialized when receiving a paging notification from the second wireless unit, and based on a value of the timer, stops a receive diversity operation of the first wireless unit only during a PTW interval in which the second wireless unit receives paging.
Radio equipment. a first wireless unit that performs wireless communication using a first wireless method;
a second wireless unit that performs wireless communication using a second wireless system;
a control unit that controls the first radio unit and the second radio unit;
a plurality of antennas, each antenna being three or more;
the control unit changes whether each of the plurality of antennas is connected to the first wireless unit and used for wireless communication of the first wireless method, or connected to the second wireless unit and used for wireless communication of the second wireless method, between a communication interval by the second wireless method and a communication interval other than the second wireless method.
Radio equipment.