Methods and apparatus for implementing and using a maximum rate option indicator

• US 20060203772A1
• Filed: 09/19/2005
• Published: 09/14/2006
• Est. Priority Date: 03/08/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Jin, Hui, Richardson, Tom
• Granted Patent: US 7,885,293 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 28/22 Negotiating communication rate

Abstract

A base station selects a maximum rate option indicator value for an uplink communications segment, e.g., uplink traffic channel segment, and transmits the selected indicator value, e.g., as part of the assignment message. The maximum rate option indicator value indicates to the wireless terminal a maximum allowed data rate option that the wireless terminal is permitted to use for the corresponding assigned uplink communications segment, the wireless terminal determining the actual uplink rate option used. Each uplink data rate option corresponds to: a number of information bits to be communicated in an uplink communication segment, a coding rate, and a modulation method. Some embodiments include multiple types of maximum uplink rate option indicators, e.g., a first type using a single bit and a second type using at least three bits. Different modulation methods are, in some embodiments, used for communicating the different types of maximum uplink rate option indicators.

Claims

1. A method of operating a base station in a communications system to transmit assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration, the method comprising:

transmitting over a wireless communications channel a first assignment including a first maximum uplink rate option indicator value indicating a first maximum uplink rate option to be used by a wireless terminal in determining the actual uplink transmission rate to be used when transmitting in a first communications segment corresponding to said first assignment.

2. The method of claim 1, wherein said communications segments are OFDM communications segments including multiple tones used for a plurality of OFDM symbol transmission time periods.

3. The method of claim 2, wherein said system supports a fixed number of different uplink rate options, the method further comprising:

selecting a maximum rate option indicator value, prior to transmitting said value, said value being selected from a set of values including at least one value corresponding to the highest uplink rate option supported by said system and another value corresponding to an intermediate rate option supported by said system.

4. The method of claim 3, wherein said first maximum uplink rate option indicator is of a first type and including a first number of bits, further comprising:

transmitting over said wireless communications channel a second assignment including a second maximum uplink rate option indicator of a second type, said second type maximum uplink rate option indicator value including more bits than said first type allowing for more maximum uplink rate options to be specified than said first type indicator.

5. The method of claim 4, wherein the first type indicator includes at most one bit and the second type indicator includes at least 3 bits.

6. The method of claim 5, wherein transmitting the second type includes using a different modulation method than a modulation method used to transmit the first type maximum uplink rate indicator values.

7. The method of claim 6, wherein the base station transmits assignments including max rate indicators of the first type according to a predetermined periodic transmission schedule having a fixed timing relationship to the uplink segments being assigned.

8. The method of claim 7, wherein said communications segments are traffic channel segments.

9. The method claim 1 further comprising:

storing first and second maximum rate option indicator tables;

using said first table for first type indicator assignments and using second table for second type indicator assignments.

10. The method of claim 9, wherein said second table includes each supported rate option.

11. A base station for use in a communications system, comprising:

a transmitter for transmitting assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration over a wireless communications channel; and

an assignment generation module for generating assignment signals to be transmitted, said assignment signals including at least a first assignment including a first maximum uplink rate option indicator value indicating a first maximum uplink rate option to be used by a wireless terminal in determining an actual uplink transmission rate to be used when transmitting into a first communications segment corresponding to said first assignment.

12. The base station of claim 11, wherein said transmitter is an OFDM transmitter;

and

wherein said communications segments are OFDM communications segments including multiple tones used for a plurality of OFDM symbol transmission time periods.

13. The base station of claim 12, wherein said system supports a fixed number of different uplink rate options, the base station further comprising:

a selection module for selecting a maximum rate option indicator value, prior to transmitting said value, said value being selected from a set of values including at least one value corresponding to the highest uplink rate option supported by said system and another value corresponding to an intermediate rate option supported by said system.

14. The base station of claim 13, wherein said first maximum uplink rate option indicator is of a first type and including a first number of bits;

and

wherein said assignment generation module for generating assignment signals includes means for generating a second assignment including a second maximum uplink rate option indicator of a second type, said second type maximum uplink rate option indicator value including more bits than said first type allowing for more maximum uplink rate options to be specified than said first type indicator.

15. The base station of claim 14, wherein the first type indicator includes at most one bit and the second type indicator includes at least 3 bits.

16. The base station of claim 15, wherein said transmitter includes first and second modulation modules, the first modulation module being used to modulate the first assignment signal, the second modulation module being used to modulate the second assignment signal, the first and second modulation modules performing different types of modulation.

17. The base station of claim 16, wherein the base station further includes:

a transmission control module which controls transmission of assignments including max rate indicators of the first type according to a predetermined periodic transmission schedule having a fixed timing relationship to the uplink segments being assigned.

18. The base station of claim 17, wherein said communications segments are traffic channel segments.

19. The base station of claim 11 further comprising:

memory for storing first and second maximum rate option indicator tables; and

wherein said assignment generation module uses said first table for generating first type indicator assignments and uses said second table for generating second type indicator assignments.

20. The base station of claim 19, wherein said second table includes each supported rate option.