Mobile communication system

• US 6,374,080 B2
• Filed: 01/05/2001
• Issued: 04/16/2002
• Est. Priority Date: 06/17/1999
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Uchida, Yoshinori
• Primary Examiner(s): Legree, Tracy
• Application Number:
  US09/754,108
• Publication Number:
  US 20010004583A1
• Time in Patent Office: 466 Days
• Field of Search: 455/12.1, 455/13.1, 455/13.2, 455/13.4, 455/11.1, 455/427, 455/428, 455/430, 455/15, 455/60.502, 455/552, 455/553, 455/426, 455/432, 455/435, 455/436, 455/448, 455/440, 455/444, 455/517, 370/519, 375/267, 375/354
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform

Abstract

In cases where a radio communication is performed between a ground radio base station and a subscriber station, when a delay time J passes after the transmission of a radio wave from the ground radio base station to a stratospheric platform base station, another radio wave relating to the same information as that indicated by the radio wave is transmitted from the ground radio base station to the subscriber station. Therefore, in the subscriber station, a phase of the radio wave directly transmitted from the ground radio base station is synchronized with a phase of the radio wave transmitted from the ground radio base station through the stratospheric platform base station. Accordingly, the subscriber station can change over from one radio wave, of which the strength is weakened, to another radio wave.

Claims

1. A mobile communication system, comprising:

a ground radio base station for converting information transmitted from a mobile switching center into a radio wave and transmitting the radio wave;

a stratospheric platform base station for receiving the radio wave transmitted from the ground radio base station and transferring the information included in the radio wave; and

a subscriber station for receiving both the radio wave transmitted from the ground radio base station and the radio wave transferred from the stratospheric platform base station, wherein the ground radio base station transmits another radio wave relating to the same information as that of the radio wave to the subscriber station when a prescribed delay time passes after the transmission of the radio wave from the ground radio base station to the stratospheric platform base station.

2. A mobile communication system according to claim 1, wherein the ground radio base station receives phase difference information from the subscriber station and adjusts the prescribed delay time in cases where the subscriber station compares a phase of the radio wave transmitted from the ground radio base station with a phase of the radio wave transmitted from the stratospheric platform base station and transmits the phase difference information.

3. A mobile communication system according to claim 2, wherein the subscriber station has a plurality of phase detectors for respectively detecting phase difference information and transmits the pieces of phase difference information to a plurality of ground radio base stations.

4. A mobile communication system according to claim 2, wherein the subscriber station transmits the phase difference information in which one symbol length is a minimum unit.

5. A mobile communication system according to claim 2, wherein the subscriber station transmits the phase difference information in which one chip rate length is a minimum unit.

6. A mobile communication system according to claim 1, wherein the ground radio base station compares a phase of the radio wave transmitted from the stratospheric platform base station with a phase of the radio wave transmitted to the subscriber station and adjusts the prescribed delay time according to a comparison result.

7. A mobile communication system according to claim 6, wherein the ground radio base station adjusts the prescribed delay time according to the comparison result in which one symbol length is a minimum unit.

8. A mobile communication system according to claim 6, wherein the ground radio base station adjusts the prescribed delay time according to the comparison result in which one chip rate length is a minimum unit.

9. A mobile communication system according to claim 1, wherein the stratospheric platform base station receives the radio wave transmitted from the ground radio base station, measures a frame length of the radio wave, compares the frame length with a standard frame length and adjust a delay time extending from the reception of the radio wave to the transferring of the radio wave according to a comparison result.

10. A mobile communication system according to claim 9, wherein the stratospheric platform base station adjusts a delay time for each of radio waves transmitted from a plurality of ground radio base stations in cases where link channels are set between the stratospheric platform base station and the plurality of ground radio base stations.

11. A mobile communication system according to claim 10, wherein the stratospheric platform base station receives a plurality of radio waves transmitted from a plurality of ground radio base stations, the stratospheric platform base station selects one of the radio waves, and the stratospheric platform base station transfers the selected radio wave to the subscriber station.

12. A mobile communication system according to claim 1, wherein the stratospheric platform base station receives the radio wave transmitted from the ground radio base station, measures a multi-frame length of the radio wave, compares the multi-frame length with a standard multi-frame length and adjust a delay time extending from the reception of the radio wave to the transferring of the radio wave according to a comparison result.

13. A mobile communication system according to claim 1, wherein the stratospheric platform base station receives the radio wave transmitted from the ground radio base station, measures a super-frame length of the radio wave, compares the super-frame length with a standard super-frame length and adjust a delay time extending from the reception of the radio wave to the transferring of the radio wave according to a comparison result.

14. A mobile communication system according to claim 1, wherein the ground radio base station makes time slots composing a frame include TDMA signals and time divided CDMA signals to construct the information to be transmitted.

15. A mobile communication system according to claim 1, wherein the ground radio base station makes time slots, which are successively transferred along a time axis and are selected from a plurality of time slots composing a frame, include one or more TDMA signals and one or more time divided CDMA signals to construct the information to be transmitted.