Signal transmission system and signal transmission method

• US 20060178162A1
• Filed: 06/24/2005
• Published: 08/10/2006
• Est. Priority Date: 02/04/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Oba, Toshinao, Ono, Mitsuhiro, Kawashima, Shinichi, Utakouji, Akira, Tsuji, Kazutomo
• Application Number:
  US11/166,057
• Publication Number:
  US 20060178162A1
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters

Abstract

A signal transmission system for transmitting an UP LINK signal received by an antenna shared by at least a first radio communication system and a second radio communication system to at least a radio base station of the first radio communication system is provided. In the signal transmission system, the first radio communication system is affected by a spurious signal of a radio communication system other than the first radio communication system, and the signal transmission system includes: a determination part for determining whether a signal level of a signal, included in the UP LINK signal, from at least the second radio communication system exceeds a permissible level; and a level adjustment part for adjusting a power level of the UP LINK signal so as to output an adjusted signal according to the determination result, and sending the adjusted signal to the radio base station.

Claims

1. A signal transmission system for transmitting an UP LINK signal received by an antenna shared by at least a first radio communication system and a second radio communication system to at least a radio base station of the first radio communication system, wherein the first radio communication system is affected by a spurious signal of a radio communication system other than the first radio communication system, the signal transmission system comprising:

a determination part for determining whether a signal level of a signal, included in the UP LINK signal, from at least the second radio communication system exceeds a permissible level; and

a level adjustment part for adjusting a power level of the UP LINK signal so as to output an adjusted signal according to the determination result, and sending the adjusted signal to the radio base station.

2. The signal transmission system as claimed in claim 1, wherein the first radio communication system conforms to a radio scheme having a power control function.

3. The signal transmission system as claimed in claim 2, wherein the radio scheme is a CDMA scheme.

4. The signal transmission system as claimed in claim 2, wherein the second radio communication system conforms to a radio scheme without the power control function.

5. The signal transmission system as claimed in claim 4, wherein the radio scheme without the power control function is a PHS scheme, a PCS scheme or a LAN scheme.

6. The signal transmission system as claimed in claim 1, wherein the antenna is provided in an indoor space.

7. The signal transmission system as claimed in claim 1, wherein the antenna is shared by the first radio communication system, the second radio communication system, and a third radio communication system.

8. The signal transmission system as claimed in claim 1, wherein the antenna is affected by an unwanted wave.

9. The signal transmission system as claimed in claim 7, wherein the determination part determines whether a signal level of a signal, included in the UP LINK signal, from the second radio communication system exceeds a permissible level, and determines whether a signal level of a signal, included in the UP LINK signal, from the third radio communication system exceeds a permissible level.

10. The signal transmission system as claimed in claim 7, wherein the first radio communication system conforms to a CDMA scheme without a power control function.

11. The signal transmission system as claimed in claim 10, wherein the second radio communication system is a system conforming to a TDD scheme, and the third radio communication system is a LAN system.

12. The signal transmission system as claimed in claim 11, the signal transmission system further comprising a radio access point for performing signal conversion between a signal of the LAN system and a signal transmitted via the antenna, wherein the radio access point is connected to a transmission cable different from a transmission cable connecting between the radio base station and the level adjustment part.

13. The signal transmission system as claimed in claim 1, wherein plural antennas are provided, and the determination part and the level adjustment part are provided for each of the plural antennas.

14. The signal transmission system as claimed in claim 13, the signal transmission system further comprising a synthesizing part for synthesizing outputs from each level adjustment part.

15. The signal transmission system as claimed in claim 1, the signal transmission system further comprising a detection part for detecting timing for switching between UP LINK and DOWN LINK lines in the second radio communication system operating under a TDD scheme,

wherein the determination part performs the determination in a period of time when the antenna receives an UP LINK signal from the second radio communication system.

16. The signal transmission system as claimed in claim 15, wherein the detection part detects a synchronization pattern included in a DOWN LINK signal.

17. A signal transmission method for transmitting an UP LINK signal received by an antenna shared by at least a first radio communication system and a second radio communication system to at least a radio base station of the first radio communication system, wherein the first radio communication system is affected by a spurious signal of a radio communication system other than the first radio communication system, the signal transmission system comprising the steps of:

determining whether a signal level of a signal, included in the UP LINK signal, from at least the second radio communication system exceeds a permissible level;

adjusting a power level of the UP LINK signal to output an adjusted signal according to the determination result; and

sending the adjusted signal to the radio base station.