Multicarrier reverse link timing synchronization system, device and method

• US 5,802,044 A
• Filed: 04/26/1996
• Issued: 09/01/1998
• Est. Priority Date: 04/26/1996
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Baum, Kevin, Kelton, James Robert, Rasky, Phillip David
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): RAO, SEEMA SRINIVAS
• Application Number:
  US08/639,155
• Time in Patent Office: 858 Days
• Field of Search: 370/310, 370/321, 370/324, 370/337, 370/344, 370/345, 370/347, 370/348, 370/350, 370/330, 375/316, 375/340, 375/344, 375/354, 375/362, 375/365, 375/371, 375/375, 379/56, 379/58-61, 455/39, 455/49.1, 455/53.1, 455/54.1, 455/56.1, 455/67.1, 455/68, 455/69
• US Class Current: 370/330
• 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 56/0005 synchronizing of arrival of multiple uplinks

Abstract

The present invention provides a communication system, device and method of reverse link symbol timing synchronization of transmited signals to facilitate reverse link timing synchronization. A base unit transmits a forward link signal, receives a reverse link signal, and determines a timing offset for signals received on a reverse link timing synchronization channel, wherein the reverse link synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by a multicarrier subscriber unit to facilitate reverse link symbol timing synchronization. A plurality of multicarrier subscriber units receive a forward link signal and transmit a reverse link symbol timing synchronization burst on a reverse link timing synchronization channel wherein the reverse link timing synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by each subscriber unit, and adjusts a timing reference for transmitting signals to facilitate reverse link timing synchronization.

Claims

1. A communication system including:

A) a base unit, for transmitting a forward link signal, receiving a multicarrier reverse link signal, and determining a timing offset for signals received on a reverse link timing synchronization channel, wherein the reverse link synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by a subscriber unit which tranmits a multicarrier signal to facilitate reverse link multicarrier signal symbol timing synchronization, and

B) a plurality of subscriber units which transmit multicarrier signals, for receiving a forward link signal, transmitting a reverse link symbol timing synchronization burst on a reverse link timing synchronization channel wherein the reverse link timing synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by each subscriber unit, and adjusting a timing reference for transmitting signals to facilitate reverse link timing synchronization.

2. The communication system of claim 1 wherein the reverse link timing synchronization channel further includes predetermined time intervals.

3. The communication system of claim 1 wherein access by each subscriber unit of the reverse link timining synchronization channel is contention-based.

4. The communication system of claim 1 wherein access by each subscriber unit of the reverse link timing synchronization channel occurs on a recurring schedule base.

5. A communication system including:

A) a base unit, for transmitting a forward link signal, receiving a multicarrier reverse link signal, and determining a timing offset for signals received on a reverse link timing synchronization channel, wherein the synchronization channel comprises a plurality of adjacent reverse link carrier frequencies that are utilized by a subscriber unit that transmits a multicarrier signal to facilitate reverse link symbol timing synchronization, and

B) a plurality of subscriber units which transmit multicarrier signals, for receiving a forward link signal, transmitting a reverse link symbol timing synchronization burst on a first reverse link timing synchronization channel wherein the first reverse link timing synchronization channel comprises predetermined time intervals and a plurality of adjacent reverse link carrier frequencies to facilitate initial reverse link timing synchronization, and uses a second reverse link timing synchronization channel comprising predetermined time intervals and at least one reverse link carrier frequency, and adjusting a timing reference for transmitting signals, to facilitate tracking updates of reverse link timing synchronization.

6. The communication system of claim 5 wherein the reverse link timing synchronization channel further includes predetermined time intervals.

7. The communication system of claim 5 wherein access by each subscriber unit of the reverse link timining synchronization channel is contention-based.

8. The communication system of claim 5 wherein access by each subscriber unit of the reverse link timing synchronization channel occurs on a recurring schedule base.

9. A subscriber unit that transmits multicarrier signals including:

(A) a reverse link timing synchronization signal generator, coupled to a transmitter, for generating a formatted reverse link symbol timing synchronization message for a reverse link timing synchronization channel, with the reverse link timing synchronization channel having at least a plurality of adjacent reverse link carrier frequencies, and for generating a reverse link symbol timing synchronization burst containing the formatted timing synchronization message,

B) a timing reference adjustment unit, coupled to the transmitter, a receiver, and the reverse link timing synchronization signal generator, for adjusting a transmit timing of the reverse link signal in response to a timing offset message from a forward link received signal,

C) the transmitter, coupled to the reverse link timing synchronization signal generator and the timing reference adjustment unit, for transmitting multicarrier reverse link signals including the reverse link timing synchronization signal, and;

D) the receiver, coupled to the timing reference adjustment unit, for receiving a forward link signal containing the timing offset message.

10. The subscriber unit of claim 9 wherein the reverse link timing synchronization channel further includes predetermined time intervals.

11. The subscriber unit of claim 9 wherein access by each subscriber unit of the reverse link timining synchronization channel is contention-based.

12. The subscriber unit of claim 9 wherein access by each subscriber unit of the reverse link timing synchronization channel occurs on a recurring schedule base.

17. The subscriber unit of claim 9 wherein the reverse link symbol timing synchronization message includes a code to identify the subscriber unit.

18. The subscriber unit of claim 9 wherein the subscriber unit transmits the reverse link symbol timing synchronization burst on a single carrier of the reverse link timing synchronization channel.

19. The subscriber unit of claim 9 wherein the subscriber unit transmits the reverse link symbol timing synchronization burst in a single symbol time interval of the reverse link timing synchronization channel.

13. A base unit for receiving multicarrier signals including:

(A) a receiver, for receiving a reverse link symbol timing synchronization burst containing a reverse link symbol timing synchronization message received on a reverse link timing synchronization channel, with the reverse link timing synchronization channel having a plurality of adjacent reverse link carrier frequencies,

B) a reverse link timing synchronization signal analyzer, coupled to the receiver, for measuring a timing of a reverse link timing synchronization message, and for comparing the measured timing to a predetermined reference timing to determine a timing offset value,

C) a timing offset message generator, coupled to the reverse link timing synchronization signal analyzer, for generating a timing offset message responsive to the timing offset value, and

D) a transmitter, coupled to the timing offset message generator, for transmitting a forward link signal containing the timing offset message.

14. The base unit of claim 13 wherein the reverse link timing synchronization channel further includes predetermined time intervals.

15. The base unit of claim 13 wherein access by a subscriber unit of the reverse link timining synchronization channel is contention-based.

16. The base unit of claim 13 wherein access by a subscriber unit of the reverse link timing synchronization channel occurs on a recurring schedule base.

20. The base unit of claim 13 further including a tracking mode single carrier demodulator, coupled to the receiver, which, according to a modulated data carrier frequency sequence schedule, demodulates a single modulated data carrier of a received multicarrier reverse link signal and estimates a symbol timing offset of the modulated data carrier, wherein different single modulated data carriers are demodulated at different time intervals in accordance with the modulated data carrier frequency sequence schedule.

21. The base unit of claim 13 further including a reverse link symbol timing synchronization single carrier demodulator, coupled to the receiver, which demodulates a single carrier of a reverse link symbol timing synchronization burst received on the reverse link timing synchronization channel and estimates a symbol timing offset of the reverse link symbol timing synchronization burst.

22. A method for reverse link symbol timing synchronization of multicarrier signals including the steps of:

A) generating a formatted reverse link symbol timing synchronization message for a reverse link timing synchronization channel, with the reverse link timing synchronization channel having at least a plurality of adjacent reverse link carrier frequencies, and for generating a reverse link symbol timing synchronization burst containing the formatted timing synchronization message,

B) adjusting a transmit timing of a reverse link signal in response to a timing offset message from a forward link received signal,

C) transmitting multicarrier reverse link signals including the reverse link timing synchronization signal, and

D) receiving a forward link signal containing the timing offset message.

23. The method of claim 22 wherein the reverse link timing synchronization channel further includes predetermined time intervals.

24. The method of claim 22 wherein access by each subscriber unit of the reverse link timining synchronization channel is contention-based.

25. The method of claim 22 wherein access by each subscriber unit of the reverse link timing synchronization channel occurs on a recurring schedule base.