Wireless communication system
A wireless communication system includes a base station and direct wave communication stations that communicate with the base station. At least one of the base station and the direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication. One of the plurality of direct wave communication stations receives a narrowband carrier in the divided band.
1. A wireless communication system comprising:
a base station; and
a plurality of direct wave communication stations that communicate with the base station,
wherein
at least one of the base station and the plurality of direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication, and
one of the plurality of direct wave communication stations receives a narrowband carrier transmitted by another direct wave communication station in the divided band.
2. The wireless communication system according to claim 1 , wherein
the band for direct wave communication is a band for uplink communication, and
the number-of-bands switching unit switches a ratio of a number of bands for downlink communication to the number of bands for direct wave communication to a state of 1:1 and a state of 1:N (where N is a positive integer equal to or larger than 2).
3. The wireless communication system according to claim 1 , wherein
the base station transmits a control signal for making an instruction for setting the number of bands for direct wave communication to a specific direct wave communication station of the plurality of direct wave communication stations.
4. The wireless communication system according to claim 3 , wherein
the specific direct wave communication station sets the narrowband carrier for transmission for a transmitter on the basis of the control signal.
5. The wireless communication system according to claim 3 , wherein
the base station sets the divided band for reception for a receiver on the basis of the control signal.
6. The wireless communication system according to claim 1 , wherein
the narrowband carrier is subjected to ASK modulation.
7. The wireless communication system according to claim 1 , wherein
the narrowband carrier is intermittent.
8. The wireless communication system according to claim 1 , wherein
the number-of-bands switching unit monitors the communication state and, with reference to the communication state, sets at least one of a carrier frequency, a bandwidth, a modulation processing, a demodulation processing, an encoding processing, a decoding processing, and a transmission power.
9. A base station of a wireless communication system comprising:
the base station; and
a plurality of direct wave communication stations that communicate with the base station,
wherein
at least one of the base station and the plurality of direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication, and the base station receives a narrowband carrier transmitted to one of the plurality of direct wave communication stations by another direct wave communication station in the divided band.
10. The base station according to claim 9 , wherein
the band for direct wave communication is a band for uplink communication, and
the number-of-bands switching unit switches a ratio of a number of bands for downlink communication to the number of bands for direct wave communication to a state of 1:1 and a state of 1:N (where N is a positive integer equal to or larger than 2).
11. The base station according to claim 9 , wherein
the base station transmits a control signal for making an instruction for setting the numbers of bands for direct wave communication to a specific direct wave communication station of the plurality of direct wave communication stations.
12. The base station according to claim 11 , wherein
the base station sets the narrowband carrier for reception for a receiver on the basis of the control signal.
13. The base station according to claim 9 , wherein
the narrowband carrier is intermittent.
14. The base station according to claim 9 , wherein
the number-of-bands switching unit monitors the communication state and, with reference to the communication state, sets at least one of a carrier frequency, a bandwidth, a modulation processing, a demodulation processing, an encoding processing, a decoding processing, and a transmission power.
15. A direct wave communication station of a wireless communication system comprising:
a base station; and
a plurality of direct wave communication stations that communicate with the base station,
wherein
at least one of the direct wave communication stations includes a number-of-bands switching unit that switches, on the basis of a communication state, a number of bands for direct wave communication, by dividing a band for direct wave communication, and
one of the plurality of direct wave communication stations receives a narrowband carrier transmitted by another direct wave communication station in the divided band.
16. The direct wave communication station according to claim 15 , wherein
the band for direct wave communication is a band for uplink communication, and
the number-of-bands switching unit switches a ratio of a number of bands for downlink communication to the number of bands for direct wave communication to a state of 1:1 and a state of 1:N (where N is a positive integer equal to or larger than 2).
17. The direct wave communication station according to claim 15 , wherein
the base station transmits a control signal for making an instruction for setting the number of bands for direct wave communication to a specific direct wave communication station of the plurality of direct wave communication stations.
18. The direct wave communication station according to claim 17 , wherein
the direct wave communication station sets the narrowband carrier for transmission for a transmitter on the basis of the control signal.
19. The direct wave communication station according to claim 15 , wherein
the narrowband carrier is subjected to ASK modulation.
20. The direct wave communication station according to claim 15 , wherein
the number-of-bands switching unit monitors the communication state and, with reference to the communication state, sets at least one of a carrier frequency, a bandwidth, a modulation processing, a demodulation processing, an encoding processing, a decoding processing, and a transmission power.