COMMUNICATIONS APPARATUS, COMMUNICATIONS SYSTEM, COMMUNICATIONS METHOD, AND INTEGRATED CIRCUIT

• US 20120069893A1
• Filed: 12/08/2010
• Published: 03/22/2012
• Est. Priority Date: 03/31/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Shirakata, Naganori, Kobayashi, Daisuke
• Granted Patent: US 9,065,698 B2
• Time in Patent Office: Days
• US Class Current: 375/239
• CPC Class Codes: H04L 25/0262 Arrangements for detecting the data rate of an incoming signal
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828
• CPC Class Codes: H04L 27/06 Demodulator circuits; Receiver circuits

Abstract

A radio (102) in a sensor network and powered by electricity includes a data communicating unit (114) performing data communication; and a pulse interval demodulating unit (111) configured to (i) detect, from a signal (11c) with signals for corresponding frequency channels overlapped, a frequency channel indicated by a time interval between two pulses in a wake-up signal (1R) included in one of the frequency channels and (ii) cause the data communicating unit (114) to perform the data communication over the detected frequency channel.

Claims

1. A communications apparatus comprising:

a data communicating unit configured to perform data communication; and

a frequency channel detecting unit configured to (i) detect, from a signal with signals for corresponding frequency channels overlapped, a frequency channel indicated by a time interval between two pulses in a wake-up signal included in one of the frequency channels and (ii) cause said data communicating unit to perform the data communication over the detected frequency channel.

2. The communications apparatus according to claim 1,

wherein the detected frequency channel indicated by the interval between the two pulses is selected from among the frequency channels by a second communications apparatus which is different from said communications apparatus that is a first communications apparatus,

the wake-up signal is generated of wake-up information including at least address information by pulse interval modulation based on a code assigned to the frequency channel over which the wake-up signal is transmitted, the address information specifying a partner communications apparatus performing data communication with the second communications apparatus, and

said frequency channel detecting unit is configured to:

(i) carry out pulse interval demodulation on the signal including the signals for the corresponding frequency channels, based on the code of the wake-up signal, to reproduce the wake-up information, and (ii) when the address information included in the wake-up information specifies the first communications apparatus, detect the frequency channel assigned to the code as the frequency channel over which the wake-up signal is transmitted, based on the code used for pulse interval demodulation, so as to have said data communicating unit use the detected frequency channel for the data communication.

3. The communications apparatus according to claim 2, further comprising

a frequency converting unit,

wherein the first communications apparatus is (i) a part of an apparatus included in a sensor network and obtaining information and (ii) different from the second communications apparatus which transmits the wake-up signal to establish the data communication with the first communications apparatus,

said frequency converting unit is configured to generate, from an input signal received via an antenna and including radio-frequency signals for the corresponding frequency channels, a low-frequency signal including low-frequency signals each transmitted on a corresponding one of the radio-frequency signals,

said frequency channel detecting unit is configured to determine, from the generated low-frequency signal, whether or not the wake-up signal is already transmitted over the detected frequency channel among the frequency channels, and

said data communicating unit is configured to (i) perform the data communication with the second communications apparatus when said frequency channel detecting unit detects the transmission of the wake-up signal, and (ii) avoid the data communication when said frequency channel detecting unit does not detect the transmission.

4. The communications apparatus according to claim 3,

wherein said frequency converting unit includes:

a bandpass filter which filters the input signal to generate a signal for the frequency channels;

an amplifier which amplifies the signal; and

an envelope detector which detects envelopes of the amplified radio-frequency signals to generate the low-frequency signal including the low-frequency signals for the frequency channels, and

when the low-frequency signal is generated from the input signal, said frequency converting unit consumes less power than power consumed in a super heterodyne technique to generate the low-frequency signal.

5. The communications apparatus according to claim 4,

wherein, when said frequency channel detecting unit detects the transmission of the wake-up signal, said data communicating unit is configured to perform the data communication over the frequency channel indicated by the interval of the detected wake-up signal.

6. A communications apparatus comprising:

a data communicating unit configured to perform data communication over a frequency channel selected from among frequency channels with a first communications apparatus which is different from said communications apparatus that is a second communications apparatus; and

an interval control unit configured to transmit, to the first communications apparatus, a wake-up signal including two pulses whose time interval indicates the selected frequency channel.

7. The communications apparatus according to claim 6,

wherein said interval control unit is configured to cause said data communicating unit to transmit the wake-up signal over the frequency channel for the data communication, the wake-up signal being generated, by pulse interval modulation, from wake-up information including at least address information specifying a communications apparatus with which the data communication is performed, and the pulse interval modulation being carried out based on a code assigned to the frequency channel for the data communication.

8. The communications apparatus according to claim 6, further comprising

a control unit configured to select one of the frequency channels such that the wake-up signal is transmitted over the selected frequency channel,

wherein said control unit is configured to select a frequency channel other than the frequency channel indicated by the wake-up signal to be (i) used for communication by a third communications apparatus and (ii) transmitted from the third communications apparatus.

9. A communications system comprising:

a first communications apparatus; and

a second communications apparatus,

wherein said second communications apparatus includes;

a second data communicating unit configured to perform data communication over a frequency channel selected from among frequency channels with said first communications apparatus; and

an interval control unit configured to transmit, to said first communications apparatus, a wake-up signal including two pulses whose time interval indicates the selected frequency channel, and

said first communications apparatus includes;

a first data communicating unit configured to perform the data communication; and

a frequency channel detecting unit configured to (i) detect, from a signal including signals for corresponding frequency channels, the frequency channel indicated by the time interval between two pulses in the wake-up signal included in one of the detected frequency channels and (ii) cause said first data communicating unit to perform the data communication over the detected frequency channel.

10. The communications system according to claim 9,

wherein said second communications apparatus includes:

a control unit configured to (i) output (a) wake-up information including address information specifying a partner of the data communication performed by said second data communicating unit and (b) frequency channel information specifying the frequency channel over which the wake-up signal is transmitted and (ii) control activation of said second data communicating unit; and

an encoding unit configured to encode the outputted wake-up information based on a code assigned to the outputted frequency channel information,

said interval control unit is configured to generate pulses and convert an output from said encoding unit into an interval between the generated pulses,

said second communications apparatus includes;

a second frequency converting unit configured to convert an output from said interval control unit into a wireless signal having the frequency channel over which the wake-up signal is transmitted; and

a second antenna from which an output of said second frequency converting unit is transmitted,

based on the control of the activation of said second data communicating unit by said control unit, said second data communicating unit is configured to perform the data communication with the partner via said second frequency converting unit and said second antenna,

said first communications apparatus includes;

a first antenna which receives the wireless signal;

a first frequency converting unit configured to convert the wireless signal received by said first antenna into the signal (i) having a predetermined frequency band suitable to demodulation and (ii) including the signals having corresponding frequency channels; and

a decoding unit,

said frequency channel detecting unit is configured to detect the interval between the two pulses of the signal (i) converted by said first frequency converting unit and (ii) including the signals having the corresponding frequency channels,

said decoding unit is configured to decode the detected interval based on the code indicated by the interval to detect the wake-up information and the frequency channel information, the interval being at least one interval,

when the address information included in the wake-up information outputted by said decoding unit specifies said first communications apparatus, said first data communicating unit is configured to perform the data communication with said second communications apparatus over the specified frequency channel, based on the frequency channel information detected by said decoding unit, using said first frequency converting unit which is set to the frequency channel to be indicated by the frequency channel information.

11. A communications method comprising:

performing data communication; and

detecting, from a signal with signals for corresponding frequency channels overlapped, a frequency channel indicated by a time interval between two pulses in a wake-up signal included in one of the frequency channels and causing in said performing to perform the data communication over the detected frequency channel.

12. A communications method comprising:

performing data communication over a frequency channel selected from among frequency channels with a first communications apparatus which is different from a second communications apparatus performing said communications method; and

transmitting, to the first communications apparatus, a wake-up signal including two pulses whose time interval indicates the selected frequency channel.

13. An integrated circuit comprising:

a data communicating unit configured to perform data communication; and

a frequency channel detecting unit configured to (i) detect, from a signal with signals for corresponding frequency channels overlapped, a frequency channel indicated by a time interval between two pulses in a wake-up signal included in one of the frequency channels and (ii) cause said data communicating unit to perform the data communication over the detected frequency channel.

14. An integrated circuit comprising:

a data communicating unit configured to perform data communication over a frequency channel selected from among frequency channels with a first communications apparatus which is different from a second communications apparatus including said integrated circuit; and

an interval control unit configured to transmit, to the first communications apparatus, a wake-up signal including two pulses whose time interval indicates the selected frequency channel.