Shared signaling channel

• US 20070097853A1
• Filed: 10/27/2005
• Published: 05/03/2007
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei, Dong, Min, Khandekar, Aamod, Gore, Dhananjay, Teague, Edward
• Granted Patent: US 9,225,488 B2
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

A shared signaling channel can be used in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system to provide signaling, acknowledgement, and power control messages to access terminals within the system. The shared signaling channel can be assigned to a predetermined number of sub-carriers within any frame. The assignment of a predetermined number of sub-carriers to the shared signaling channel establishes a fixed bandwidth overhead for the channel. The actual sub-carriers assigned to the channel can be varied periodically, and can vary according to a predetermined frequency hopping schedule. The amount of signal power allocated to the signaling channel can vary on a per symbol basis depending on the power requirements of the communication link. The shared signaling channel can direct each message carried on the channel to one or more access terminals. Unicast messages allow the channel power to be controlled per the needs of individual communication links.

Claims

1. A method of generating signaling channel messages in a wireless communication system including a plurality of sub-carriers spanning an at least a portion of an operating frequency band, the method comprising:

assigning resources corresponding to a predetermined bandwidth allocated to a signaling channel;

generating at least one message;

encoding the at least one message to generate at least one message symbol;

controlling a power density of the at least one message symbol; and

modulating at least a portion of the resources allocated to the signaling channel.

2. The method of claim 1, further comprising:

transforming the plurality of sub-carriers, including at least one sub-carrier within the predetermined bandwidth allocated to the signaling channel, to an OFDM symbol; and

transmitting the OFDM symbol over a wireless communication link.

3. The method of claim 1, wherein assigning resources comprises:

determining a number of sub-carriers from the plurality of sub-carriers corresponding to the predetermined bandwidth; and

assigning a subset of the plurality of sub-carriers equal to the number of sub-carriers to the signaling channel.

4. The method of claim 1, wherein assigning resources comprises:

assigning a set of logical resources corresponding to the predetermined bandwidth to the signaling channel; and

mapping the set of logical resources to a corresponding subset of the plurality of sub-carriers.

5. The method of claim 4, wherein mapping the set of logical resources comprises mapping the set of logical resources to the corresponding subset of the plurality of sub-carriers based in part on a frequency hopping algorithm.

6. The method of claim 1, wherein generating at least one message comprises generating at least one access grant message directed to a particular access terminal.

7. The method of claim 6, wherein the at least one access grant message comprises a MACID corresponding to the particular access terminal.

8. The method of claim 1, wherein generating at least one message comprises generating at least one link assignment block message directed to a plurality of access terminals.

9. The method of claim 8, wherein the at least one link assignment block message comprises a broadcast MACID.

10. The method of claim 1, wherein generating at least one message comprises generating at least one acknowledgement (ACK) message in response to a received transmission from an access terminal.

11. The method of claim 1, wherein generating at least one message comprises generating at least one reverse power link control message directed to a particular access terminal.

12. The method of claim 1, wherein encoding the at least one message comprises:

generating a Cyclic Redundancy Code (CRC) corresponding to a single message; and

appending the CRC to the single message.

13. The method of claim 1, wherein encoding the at least one message comprises:

aggregating multiple messages to generate a combined message;

encoding the combined message; and

appending the combined message with a Cyclic Redundancy Check (CRC) corresponding to the combined message.

14. The method of claim 1, wherein modulating at least the portion of the resources comprises:

modulating a first sub-carrier allocated to the signaling channel with a first message symbol from the at least one message symbol; and

modulating a second sub-carrier allocated to the signaling channel with a second message symbol from the at least one message symbol.

15. The method of claim 1, wherein modulating at least the portion of the resources comprises interleaving the at least one message symbol across at least two sub-carriers allocated to the signaling channel.

16. A method of generating signaling channel messages in a wireless communication system including a plurality of sub-carriers spanning at least a portion of an operating frequency band, the method comprising:

generating at least one message;

encoding the at least one message to generate a plurality of message symbols;

adjusting a power density associated with the plurality of message symbols;

determining a subset of sub-carriers assigned to a signaling channel from the plurality of sub-carriers; and

modulating each of the subset of sub-carriers with at least one symbol from the plurality of message symbols.

17. The method of claim 16, wherein generating at least one message comprises generating a unicast message directed to a particular access terminal.

18. The method of claim 16, wherein generating at least one message comprises generating a multicast message directed to a particular group of access terminals.

19. The method of claim 16, wherein generating at least one message comprises generating a broadcast message directed to any access terminal within a coverage area served by the signaling channel.

20. The method of claim 16, further comprising;

transforming the plurality of sub-carriers to an OFDM symbol; and

transmitting the OFDM symbol over a wireless channel.

21. An apparatus configured to generate signaling channel messages in a wireless communication system including a plurality of sub-carriers spanning at least a portion of an operating frequency band, the apparatus comprising:

a scheduler configured to assign a subset of the plurality of sub-carriers to a signaling channel;

a signaling module configured to generate at least one signaling message;

a power control module configured to adjust a power density of the at least one signaling message; and

a signal mapper coupled to the scheduler and the signaling module and configured to map symbols from the at least one signaling message to the subset of the plurality of sub-carriers.

22. The apparatus of claim 21, wherein the scheduler is configured to assign the subset of the plurality of sub-carriers based in part on a frequency hopping algorithm.

23. The apparatus of claim 21, wherein the scheduler is configured to assign a fixed number of sub-carriers from the plurality of sub-carriers.

24. The apparatus of claim 21, wherein the at least one signaling message comprises a broadcast signaling message directed to a plurality of access terminals.

25. The apparatus of claim 21, wherein the at least one signaling message comprises a unicast signaling message directed to a particular access terminal identified by a corresponding MACID.

26. The apparatus of claim 21, wherein the power control module is configured to adjust an amplitude of each symbol from the at least one signaling message.

27. The apparatus of claim 21, further comprising an Inverse Fast Fourier Transform (IFFT) module coupled to the signal mapper and configured to transform the plurality of sub-carriers to time domain OFDM symbols.

28. An apparatus configured to generate signaling channel messages in a wireless communication system including a plurality of sub-carriers spanning at least a portion of an operating frequency band, the apparatus comprising:

means for generating at least one message;

means for encoding the at least one message to generate a plurality of message symbols;

means for adjusting a power density associated with the plurality of message symbols;

means for determining a subset of sub-carriers assigned to a signaling channel from the plurality of sub-carriers; and

means for modulating each of the subset of sub-carriers with at least one symbol from the plurality of message symbols.

29. The apparatus of claim 28, wherein the means for generating the at least one message comprises a means for generating a broadcast signaling message.

30. The apparatus of claim 28, wherein the means for generating the at least one message comprises a means for generating a unicast acknowledgement message.

31. The apparatus of claim 28, wherein the means for generating the at least one message comprises a means for generating a unicast reverse link power control message.

32. The apparatus of claim 28, wherein the means for determining the subset of sub-carriers assigned to the signaling channel comprises means for determining the subset of sub-carriers based in part on a frequency hopping algorithm.