CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International Patent Application No. PCT/JP2016/073939 filed on Aug. 16, 2016, which claims priority benefit of Japanese Patent Application No. JP 2015-197337 filed in the Japan Patent Office on Oct. 5, 2015. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present technology relates to a communication apparatus and a method for controlling the communication apparatus. More particularly, the present technology relates to a communication apparatus including a real-time clock and a method for controlling the communication apparatus.

BACKGROUND ART

In recent years, along with the evolution of technologies related to sensors, wireless communication, and cloud computing, development of Internet of Things (IoT) devices using these technologies has been advanced. Many of these IoT devices are required to be small in size and low in cost. For this reason, the IoT device is equipped with a low-capacity battery as a power supply, and various circuits and parts are commonly used from the viewpoint of reducing power consumption.

In addition, in the IoT device, a wireless signal is processed in synchronization with a clock signal from a crystal oscillator whose oscillation frequency is on the order of megahertz. As the oscillation frequency of the crystal oscillator, an integer multiple of 13 megahertz (MHz) or 19.2 megahertz (MHz) common in mobile phones, 20 megahertz (MHz) in Wi-Fi (registered trademark), and the like are used.

For example, a communication apparatus has been devised in which a clock signal from a crystal oscillator is multiplied by a phase-locked loop, and a wireless signal is transmitted and received with the multiplied clock signal (see, for example, Patent Document 1). The communication apparatus reduces power consumption by stopping each circuit except a real-time clock in a sleep mode.

CITATION LIST

Patent Document

Patent Document 1: Japanese Patent No. 5105688

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In the conventional technology described above, since the crystal oscillator and the phase-locked loop are stopped in the sleep mode, the communication apparatus cannot perform communication using clock signals from these circuits. In addition to the real-time clock, if the crystal oscillator and the like are operated even in the sleep mode, communication can be performed; however, power consumption is increased by an amount for the operated circuit or element. For this reason, it is difficult to perform communication while suppressing an increase in power consumption.

The present technology has been developed in view of such a situation, and aims that a communication apparatus performs communication while suppressing an increase in power consumption.

Solutions to Problems

The present technology has been made to solve problems described above, and a first aspect of the present technology is a communication apparatus including: a periodic signal generating unit that generates a predetermined periodic signal; a clocking unit that clocks time in synchronization with the predetermined periodic signal; a multiplication unit that multiplies the predetermined periodic signal to supply the signal as a multiplied signal; and a communication processing unit that performs predetermined communication processing in synchronization with the multiplied signal, and a method for controlling the communication apparatus. As a result, the time is clocked in synchronization with the periodic signal, and the communication processing is executed in synchronization with the multiplied signal obtained by multiplying the periodic signal.

In addition, in the first aspect, the communication apparatus may further include: a high frequency signal generating unit that generates a high frequency signal having a higher frequency than the predetermined periodic signal; and a selection unit that selects either the high frequency signal or the predetermined periodic signal to supply a selected signal to the multiplication unit. As a result, any of the high frequency signal and the predetermined periodic signal is multiplied.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a signal superimposed on a carrier, a setting unit is further included, the setting unit setting any of a plurality of frequencies as a frequency of the carrier in the communication processing unit, and the selection unit selects the predetermined periodic signal in a case where the frequency of the carrier does not exceed a predetermined frequency, and selects the high frequency signal in a case where the frequency of the carrier is higher than the predetermined frequency. As a result, in the case where the frequency of the carrier is higher than the predetermined frequency, the high frequency signal is selected.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a baseband signal, a setting unit is further included, the setting unit setting any of a plurality of frequencies as a frequency of the baseband signal in the communication processing unit, and the selection unit selects the predetermined periodic signal in a case where the frequency of the baseband signal does not exceed a predetermined frequency, and selects the high frequency signal in a case where the frequency of the baseband signal is higher than the predetermined frequency. As a result, in the case where the frequency of the baseband signal is higher than the predetermined frequency, the high frequency signal is selected.

In addition, in the first aspect, the communication apparatus may further include a temperature measurement unit that measures temperature, in which the selection unit selects the predetermined periodic signal in a case where the temperature measured is a temperature within a predetermined range, and selects the high frequency signal in a case where the temperature measured is a temperature outside the predetermined range. As a result, in the case where the measured temperature is the temperature outside the predetermined range, the high frequency signal is selected.

In addition, in the first aspect, the communication apparatus may be configured such that the temperature measurement unit includes: a thermistor whose resistance varies with a change of the temperature, and a measurement unit that measures the temperature on the basis of a voltage corresponding to the resistance. As a result, the temperature is measured from the voltage corresponding to the resistance of the thermistor.

In addition, in the first aspect, the communication apparatus may be configured such that the temperature measurement unit includes: a proportional to absolute temperature voltage circuit that generates a voltage proportional to the temperature; and a measurement unit that measures the temperature on the basis of the voltage. As a result, the temperature is measured from the voltage of the proportional to absolute temperature voltage circuit.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a signal superimposed on a carrier, and a frequency of the carrier does not exceed 13.56 megahertz. As a result, the signal superimposed on the carrier having the frequency of 13.56 MHz or less is transmitted and received.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a baseband signal, and a frequency of the baseband signal does not exceed 13.56 megahertz. As a result, the baseband signal having a frequency of 13.56 MHz or less is transmitted and received.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a packet having a packet length not exceeding 4.867 microseconds. As a result, the packet having the packet length of 4.867 microseconds or less is transmitted and received.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving data at a data rate not exceeding 424 kilobits per second. As a result, the data is transmitted and received at a data rate of 424 kilobits per second or less.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of modulating or demodulating a symbol having a symbol length not shorter than 2.36 microseconds. As a result, the symbol having the symbol length of 2.36 microseconds or more is modulated or demodulated.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a signal superimposed on a carrier, and the multiplication unit multiplies the periodic signal by a multiplication ratio higher than a value obtained by dividing a frequency of the carrier by a frequency of the predetermined periodic signal. As a result, the periodic signal is multiplied by the multiplication ratio higher than the value obtained by dividing the frequency of the carrier by the frequency of the periodic signal.

In addition, in the first aspect, the communication apparatus may be configured such that the predetermined communication processing includes processing of transmitting and receiving a baseband signal, and the multiplication unit multiplies the periodic signal by a multiplication ratio higher than a value obtained by dividing a frequency of the baseband signal by a frequency of the predetermined periodic signal. As a result, the periodic signal is multiplied by the multiplication ratio higher than the value obtained by dividing the frequency of the baseband signal by the frequency of the periodic signal.

In addition, in the first aspect, the communication apparatus may be configured such that the communication processing unit performs the communication processing in accordance with a communication standard in non-contact communication. As a result, non-contact communication is performed.

In addition, in the first aspect, the communication apparatus may be configured such that the communication processing unit performs the communication processing in accordance with a communication standard in human body communication. As a result, human body communication is performed.

Effects of the Invention

According to the present technology, it is possible to achieve an excellent effect that the communication apparatus can perform communication while suppressing an increase in power consumption. Incidentally, the effect described here is not necessarily limited, and can be any effect described in the present disclosure.

