Method and Apparatus for Uplink Timing Synchronization with Ranging Signal in Mobile Communication System

• US 20080305804A1
• Filed: 12/08/2006
• Published: 12/11/2008
• Est. Priority Date: 12/08/2005
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute, Hanaro Telecom., Inc., KT Corporation, Samsung Electronics Co. Ltd., SK Telecom Co., Ltd.
• Original Assignee: Hanaro Telecom., Inc., KT Corporation, Samsung Electronics Co. Ltd., SK Telecom Co., Ltd.
• Inventors: Yu, Chang-Wahn, Park, Youn-Ok, Lee, Young-Ha
• Granted Patent: US 8,600,420 B2
• Time in Patent Office: Days
• US Class Current: 455/446
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements

Abstract

When a base station of a time division duplex based mobile communication system receives an initial ranging request signal from a subscriber station, the base station generates initial ranging information including delay time information to the subscriber station, and receives uplink data delayed and transmitted using a delay time from the subscriber station. Also, when the subscriber station transmits an initial ranging request signal to the base station and receives initial ranging information including delay time information from the base station, the subscriber station establishes a transmission parameter value by using the transmission parameter value included in the initial ranging information and transmits uplink data by using the established delay time.

Claims

1. A method for a base station of a mobile communication system to synchronize a subscriber station and an uplink time, the method comprising:

receiving an initial ranging request signal for initial ranging from the subscriber station;

generating initial ranging information including delay time information for delay transmission of uplink data in response to the initial ranging request signal;

transmitting the initial ranging information to the subscriber station; and

receiving the uplink data transmitted with a delay by using the delay time from the subscriber station.

2. The method of claim 1, wherein the subscriber station is a subscriber station to which power is applied and is initially access to the base station or a subscriber station handed off by another base station.

3. The method of claim 1, wherein the initial ranging information includes transmission power, time, frequency offset, and the delay time information.

4. The method of claim 3, wherein the delay time is established in advance between the base station and the subscriber station according to mobile communication service types supported by the base station.

5. The method of claim 1, wherein the uplink data includes a periodic ranging code for periodic ranging or a bandwidth request code for bandwidth request ranging.

6. The method of claim 1, wherein the uplink data include data transmitted using the delay time when the bandwidth request ranging is performed with the subscriber station.

7. The method of claim 1, wherein the uplink data from a first subscriber station approaching the base station are transmitted faster within the range of the delay time than the uplink data from a second subscriber station not moving, and

the uplink data transmitted by a third subscriber station leaving the base station are transmitted later than the uplink data transmitted by the second subscriber station.

8. A method for a subscriber station of a mobile communication system to synchronize a base station and an uplink time, the method comprising:

transmitting an initial ranging request signal for initial ranging to the base station;

receiving initial ranging information including delay time information for delay transmission of uplink data from the base station;

performing initial ranging by using transmission parameter values included in the initial ranging information; and

transmitting uplink data by using a delay time established through the initial ranging.

9. The method of claim 8, wherein information on transmission power, time, frequency offset, and the delay time is checked from the initial ranging information, and the initial ranging is performed by establishing the transmission power, the time, the frequency offset, and the delay time.

10. The method of claim 8, wherein transmitting of uplink data comprises delaying a periodic ranging code for requesting to perform the periodic ranging by the delay time, and transmitting the delayed periodic ranging code to the base station when a timer established for the periodic ranging is finished.

11. The method of claim 8, wherein transmitting of uplink data comprises delaying a bandwidth request code for transmitting the uplink traffic by the delay time, and transmitting the delayed bandwidth request code to the base station when uplink traffic to be transmitted to the base station is generated.

12. The method of claim 8, wherein the uplink data include at least one of the periodic ranging code and the bandwidth request code, and

the method further comprises:

receiving a ranging response signal on the uplink data from the base station; and

controlling an initial ranging value established by the initial ranging by using the transmission parameter control values included in the ranging response signal.

13. The method of claim 12, further comprising delaying the uplink traffic by the delay time by using the controlled initial ranging value, and transmitting the delayed uplink traffic to the base station.

14. The method of claim 8, wherein a data interval to which the uplink traffic is mounted by the delay time with respect to a reference interval is advanced so as to transmit the uplink data.

15. The method of claim 14, wherein a data interval for a first subscriber station approaching the base station is transmitted to the base station in advance to the predetermined data interval, and

a data interval for a second subscriber station leaving the base station is delayed after the predetermined data interval, and is then transmitted to the base station.

16. A device for synchronizing a subscriber station and an uplink time by using a delay time in a base station of a mobile communication system, the device comprising:

means for receiving an initial ranging request signal for initial ranging from the subscriber station;

means for generating initial ranging information including delay time information established for delay transmission of uplink data in response to the initial ranging request signal;

means for transmitting the generated initial ranging information to the subscriber station; and

means for receiving the uplink data delayed and transmitted by using the delay time from the subscriber station.

17. The device of claim 16, wherein the means for receiving the uplink data receives the uplink data transmitted by a first subscriber station approaching the base station in advance to the uplink data transmitted by a second subscriber station within the range of the delay time, and receives the uplink data transmitted by a third subscriber station leaving the base station later than the uplink data transmitted by the second subscriber station.

18. A subscriber station for synchronizing a base station of a mobile communication system and an uplink time, the subscriber station comprising:

means for transmitting an initial ranging request signal for initial ranging to the base station;

means for receiving initial ranging information including delay time information established for delay transmission of uplink data from the base station;

means for performing initial ranging by using a transmission parameter value included in the initial ranging information; and

means for transmitting the uplink data by using a delay time established through the initial ranging.

19. The subscriber station of claim 18, further comprising means for controlling a transmission parameter value established through the initial ranging according to a ranging response signal received from the base station in response to a periodic ranging code for periodic ranging or a bandwidth request code transmitted for band request ranging, the ranging response signal including a transmission parameter control value.

20. The subscriber station of claim 18, wherein the means for transmitting the uplink data establishes the data interval to which the uplink traffic is mounted to be advanced by the delay time, and transmits the uplink data by using the established data interval