Method and apparatus for timing adjustment for uplink synchronous transmission in wide code division multiple access

• US 20020093940A1
• Filed: 01/12/2001
• Published: 07/18/2002
• Est. Priority Date: 01/12/2001
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Toskala, Antti, Tarkiainen, Markku
• Granted Patent: US 6,657,988 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04W 56/0075 based on arrival time vs. expected arrival time

Abstract

A method and apparatus for use in the uplink synchronous transmission in UTRA FDD. As the downlink DPCH field carries a transmit power command (TPC) in each of the slots in a radio frame, the TPC can be replaced by a Time alignment bit (TAB) to indicate whether the received arrival time at a Node B of a DPCH message from a UE is earlier or later than a desired arrival time. The TAB is sent to the UE over a number of times so as to allow the UE to adjust the uplink transmission time based on a summed value of the TABs. Preferably, the TABs are summed over 200 ms so that the searcher in Node B has sufficient time to verify the position of the UE in the time domain.

Claims

1. A method for use in a frequency division multiplex (FDD) mode of a terminal of a mobile telephone network having a plurality of base stations capable of communication with the terminal over corresponding radio uplinks and downlinks, wherein the communication is carried out in radio frames and each radio frame for the radio downlinks comprises a plurality of time slots for carrying control information, and the control information includes a transmit power command, and wherein the terminal conveys a dedicated physical channel message to one of the base stations in each radio frame for the radio uplinks according to an uplink transmission time, and said one base station is capable of comparing a received time of the message to a desired arrival time for determining the time difference therebetween and assigning to the transmit power command a value indicative of the time difference, wherein the assigned value is equal to a first value if the received time is earlier than the desired arrival time, and the assigned value is equal to a second value if the received time is later than the desired arrival time, said method comprising the steps of:

providing the terminal M assigned values over a time period equal to N radio frame times, wherein N is an integer greater than 2; and

adjusting the uplink transmission time based on the assigned values over said time period.

2. The method of claim 1, wherein M is an integer ranging from 1 to N.

3. The method of claim 1, wherein N is an even number and M is an integer ranging from 1 to N/2.

4. The method of claim 1, wherein N is an odd number and M is an integer ranging from 1 to (N+1)/2.

5. The method of claim 1, wherein the adjusting step is carried out by the terminal based on a sum of the assigned values when M is greater than or equal to 2.

6. The method of claim 1, wherein the assigned value is assigned to the transmit power command in the last time slot of the radio frame.

7. The method of claim 1, wherein the first and second values are real numbers.

8. The method of claim 1, wherein the first and second values are complex numbers.

9. The method of claim 1, wherein the first value is equal to 0 and the second value is equal to 1.

10. The method of claim 1, wherein the first value is equal to (1−

j) and the second value is equal to (1+j).

11. The method of claim 1, wherein the assigned values include a third value indicative of the received arrival time being substantially equal to the desired arrival time.

13. The apparatus of claim 12, wherein M is greater than 2, said apparatus further comprising means for summing the M assigned values and the adjusting means adjusts the uplink transmission time based on the summed value.

15. The terminal of claim 14, further comprising means for summing the assigned values when M is greater than or equal to 2, and said adjusting means adjusts the uplink transmission time based on the summed value.

12. An apparatus for use in a frequency division multiplex (FDD) mode of a terminal of a mobile telephone network having a plurality of base stations capable of communication with the terminal over corresponding radio uplinks and downlinks, wherein the communication is carried out in radio frames and each radio frame for the radio downlinks comprises a plurality of time slots for carrying control information, and the control information includes a transmit power command and wherein the terminal conveys a dedicated physical channel message to one of the base stations in each radio frame for the radio uplinks according to an uplink transmission time, and said one base station is capable of comparing a received time of the message to a desired arrival time for determining the time difference therebetween and assigning to the transmit power command a value indicative of the time difference, said apparatus comprising:

means, responsive to said time difference, for providing the terminal M assigned values over a time period equal to N radio frame times, wherein N is an integer greater than 2; and

means, responsive to the assigned values, for adjusting the uplink transmission time based on the assigned values over said time period.

14. A mobile terminal for use in a frequency division multiplex (FDD) mode of a terminal of a mobile telephone network having a plurality of base stations capable of communication with the terminal over corresponding radio uplinks and downlinks, wherein the communication is carried out in radio frames and each radio frame for the radio downlinks comprises a plurality of slots for carrying control information, and the control information includes a transmit power command, and wherein the mobile terminal has means to convey a dedicated physical channel message according to an uplink transmission time to one of said plurality of base stations in each radio frame for the radio uplinks, and said one base station is capable of comparing a received time of the message to a desired arrival time for determining the time difference therebetween, and assigning to the transmit power command a value indicative of the time difference for providing to the terminal a signal indicative of the assigned value, said terminal comprising:

means, responsive to the signal, for retrieving M assigned values over a time period equal to N radio frame times, wherein N is an integer greater than 2; and

means, responsive to the assigned values, for adjusting the uplink transmission time based on the assigned values over said time period.