Mobile satellite communication terminal

• US 5,870,665 A
• Filed: 01/26/1996
• Issued: 02/09/1999
• Est. Priority Date: 01/27/1995
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Uchikawa, Setomi
• Primary Examiner(s): Lee, Richard
• Assistant Examiner(s): Le, Vu
• Application Number:
  US08/592,689
• Time in Patent Office: 1,110 Days
• Field of Search: 455/11.1, 455/12.1, 455/13.1-13.3, 455/33.1, 455/54.1, 455/56.1, 455/20, 455/90, 455/427, 455/575
• US Class Current: 455/11.1
• CPC Class Codes: H04B 7/18536 Shadowing compensation therefor, e.g. by using an additional terrestrial relay

Abstract

In order that communication may be performed independently of indoors or outdoors, in this mobile satellite communication terminal, when it is used indoors, the indoor terminal transmitting and receiving a signal in the ground radio channel is connected to the repeater terminal installed at a position from which the satellite can be seen by the ground radio channel, further, the repeater terminal communicates with the satellite by using the satellite channel. On the other hand, when it is used outdoors, the outdoor terminal is constituted by mounting the outdoor unit for the satellite channel consisting of the antenna for the satellite channel and the radio frequency section instead of the indoor unit consisting of the antenna for the ground radio channel and the radio frequency section of the indoor terminal.

Claims

1. A mobile satellite communication system for communicating with a satellite, the system comprising:

an indoor terminal including a first detachable indoor unit which is detachably mounted to a common section, the common section providing a user interface to the system, the first detachable indoor unit including a first radio frequency circuit and a first antenna for communicating using a ground radio channel;

a repeater terminal including a second detachable indoor unit and a first detachable outdoor unit which is detachably mounted to a conversion section, said second detachable indoor unit being substantially identical in construction to said first detachable indoor unit and including a second radio frequency circuit and a second antenna for communicating with said indoor terminal using said ground radio channel, said first detachable outdoor unit including a third radio frequency circuit and a third antenna for communicating with said satellite using a satellite channel, said conversion section converting signals between said ground radio channel and said satellite channel; and

an outdoor terminal including a second detachable outdoor unit which is detachably mounted to a second common section, said second detachable outdoor unit being substantially identical in construction to said first detachable outdoor unit, and said second common section being substantially identical in construction to said first common section, said outdoor terminal communicating with said satellite using said satellite channel.

2. A mobile satellite communication system as recited in claim 1, wherein said detachable indoor and outdoor units are interchangeably attachable and detachable to said first and second common sections and said converter section.

3. A mobile satellite communication system as recited in claim 1, wherein said repeater terminal is installed at a position from which the satellite can be seen.

4. A mobile satellite communication system as recited in claim 3, wherein said conversion section alternately converts a transmission/reception frequency of the ground radio channel used by said detachable indoor unit and a transmission/reception frequency of the satellite channel used by said detachable outdoor unit.

5. A mobile satellite communication system as recited in claim 1, wherein both of said first and second common sections perform a modulation/demodulation function of a transmission/reception signal and perform a baseband processing function.

6. A mobile satellite communication system as recited in claim 1, wherein said ground radio channel uses a low frequency band such as a VHF band or less.

7. A mobile satellite communication system for communicating with a satellite the system comprising:

at least two indoor units, each of said indoor units including a ground radio frequency circuit and a ground radio channel antenna for communicating with each other using a ground radio channel;

an outdoor unit including a satellite radio frequency circuit and a satellite antenna for communicating with said satellite using a satellite channel;

a common section providing a user interface to the system;

a conversion section converting signals between said ground radio channel and said satellite channel and between said satellite channel and said ground radio channel;

an indoor terminal including a first of said indoor units detachably mounted to said common section; and

a repeater terminal including a second of said indoor units and said outdoor unit detachably mounted to said conversion section, whereby said indoor terminal communicates with said satellite through said repeater terminal.

8. A mobile satellite communication system as recited in claim 7, further comprising:

an outdoor terminal including a second outdoor unit detachably mounted to a second common section, whereby said outdoor terminal communicates directly with said satellite.

9. A mobile satellite communication system as recited in claim 8, wherein both of said first and second common sections perform modulation/demodulation of a transmission/reception signal and perform a baseband processing function.

10. A mobile satellite communication system as recited in claim 7, wherein said repeater terminal is installed at a position from which the satellite can be seen.

11. A mobile satellite communication system as recited in claim 7, wherein said conversion section alternately converts a transmission/reception frequency of the ground radio channel used by said indoor unit and a transmission/reception frequency of the satellite channel used by said outdoor unit.

12. A mobile satellite communication system as recited in claim 7, wherein said ground radio channel uses a low frequency band such as a VHF band or less.