Synchronization of timing advance and deviation

• US 20020080749A1
• Filed: 02/25/2002
• Published: 06/27/2002
• Est. Priority Date: 04/06/2000
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Terry, Stephen E.
• Granted Patent: US 7,573,913 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04B 7/2681 Synchronisation of a mobile station with one base station
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 92/10 between terminal device and access point, i.e. wireless air interface

Abstract

A system and method for reducing the latency from timing deviation (TD) measurement to time advance (TA) adjustment. The invention uses a deterministic procedure to coordinate time advance (TA) commands and timing deviation (TD) measurements so that failed transmissions or mobile terminals signal propagation changes can be recognized and corrected much more rapidly. Radio resource efficiency is maximized by minimizing signaling overhead through effectively reducing the frequency of time advance commands. This is accomplished by using TA command signals which include a Connect Frame Number (CFN) to specify particular radio frames for time advance (TA) adjustment. The potential for timing deviation (TD) measurements to be incorrectly processed in conjunction with adjusting a physical reception window and calculating mobile termination location is minimized, without excessive command signaling requirements.

Claims

1. A method of using a mobile terminal (MT) for synchronizing uplink signals in a communication system which supports base station (BS)/mobile terminal (MT) wireless bi-directional communications via the utilization of a time frame format having sequentially identified system time frames, the method comprising:

receiving communication data from a BS within system time frames including a TA signal which include TA data and a Connect Frame Number (CFN) specifying a specific frame for effectuating a timing adjustment; and

adjusting the timing of uplink transmissions of the MT in response to TA data in the received TA signal commencing in the time frame specified in the CFN of the received TA signal.

2. A mobile terminal (MT) for a communication system which supports base station (BS)/mobile terminal (MT) wireless bi-directional communications via the utilization of a time frame format having sequentially identified system time frames where BSs transmit selectively formatted communication data to MTs within system time frames, the mobile terminal (MT) comprising:

a receiver, a transmitter and an associated processor;

said receiver for receiving communication data from a BS within system time frames including timing advance (TA) signals which include TA data and a Connect Frame Number (CFN) specifying a specific frame for effectuating a timing adjustment by the selected MT;

said transmitter transmitting selectively formatted communication data to a BS within system time frames synchronized by said processor; and

said MT processor adjusting the timing of the transmissions of said MT processor in response to TA data in a received TA signal commencing in the time frame specified in the CFN of the received TA signal.