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

• US 7,885,293 B2
• Filed: 09/19/2005
• Issued: 02/08/2011
• 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
• Primary Examiner(s): Eng; George
• Assistant Examiner(s): HUYNH, NAM TRUNG
• Application Number:
  US11/230,305
• Publication Number:
  US 20060203772A1
• Time in Patent Office: 1,968 Days
• Field of Search: 455418-420, 455/424, 455/561, 455/450, 370/232, 370/235, 370/328, 370/329, 370/468
• US Class Current: 370/468
• 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:

generating a first segment assignment signal assigning a first communications segment to a wireless terminal, the first segment assignment signal including a first maximum uplink rate option indicator value having a first number of bits and indicating a first maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the first communications segment;

transmitting said first segment assignment signal to the wireless terminal over a first wireless assignment channel;

generating a second segment assignment signal assigning a second communications segment to said wireless terminal, the second segment assignment signal including a second maximum uplink rate option indicator value, said second maximum uplink rate option indicator value having a second number of bits which is more than said first number of bits and indicating a second maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the second communications segment; and

transmitting the second segment assignment signal to said wireless terminal over a second wireless assignment channel.

2. The method of claim 1,

wherein said second segment assignment signal further includes a wireless terminal identifier which identifies said wireless terminal to which said second communications segment is assigned;

and

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 1, wherein said system supports a fixed number of different uplink rate options, the method further comprising:

selecting a said first maximum rate option indicator value, prior to transmitting said first segment assignment signal, 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; and

wherein said first maximum unlink rate option indicator value is a single bit value.

9. The method claim 1 further comprising:

storing first and second maximum rate option indicator tables;

using said first maximum rate option indicator table for assignments of a first type, assignments of the first type being transmitted over said first wireless assignment channel;

using said second maximum rate option indicator table for assignments of a second type, assignments of the second type being transmitted over the second wireless assignment channel.

10. The method of claim 9,

wherein assignment signals transmitted over said first wireless assignment channel are generated using non-coherent modulation, said step of generating said first assignment signal including performing non-coherent modulation;

and

wherein assignment signals transmitted over said second wireless assignment channel are generated using coherent modulation, said step of generating said second assignment signal including performing coherent modulation.

4. A method of operating a base station in a communications system supporting a fixed number of different uplink rate options and transmitting assignment information indicating assignment of uplink OFDM communications segments, each segment having a predetermined duration and including multiple tones used for a plurality of OFDM symbol transmission time periods, the method comprising:

selecting a first maximum rate option indicator value of a first type and including a first number of bits 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;

transmitting over a wireless communications channel a first assignment including said first maximum uplink rate option indicator value of said first type 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 OFDM communications segment corresponding to said first assignment; and

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.

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

a first type assignment generation module for generating a first segment assignment signal assigning a first communications segment to a wireless terminal, the first segment assignment signal including a first maximum uplink rate option indicator value having a first number of bits and indicating a first maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining an actual uplink transmission rate to be used when transmitting into the first communications segment;

a second type assignment generation module for generating a second segment assignment signal assigning a second communications segment to said wireless terminal, the second segment assignment signal including a second maximum uplink rate option indicator value, said second maximum uplink rate option indicator value having a second number of bits which is more than said first number of bits and indicating a second maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the second communications segment; and

a transmitter for transmitting assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration over a wireless communications channel, said transmitter being configured to transmit said first assignment signal to said wireless terminal over a first wireless assignment channel and transmit said second assignment signal to said wireless terminal over a second wireless assignment channel.

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 said first maximum rate option indicator value, prior to transmitting said first assignment signal, 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; and

wherein said first maximum uplink rate option indicator value is a single bit value.

19. The base station of claim 11 further comprising:

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

wherein said first type assignment generation module uses said first maximum rate option indicator table for generating assignments of a first type, assignments of the first type being transmitted over said first wireless assignment channel, said second type assignment generation module uses said second maximum rate option indicator table for generating assignments of a second type, assignments of the second type being transmitted over the second wireless assignment channel.

20. The base station of claim 19, wherein assignment signals transmitted over said first wireless assignment channel are generated using non-coherent modulation;

and

wherein assignment signals transmitted over said second assignment channel are generated using coherent modulation.

14. A base station for use in a communications system supporting a fixed number of different uplink rate options, comprising:

an OFDM transmitter for transmitting assignment information indicating assignment of uplink OFDM communications segments, each segment having a predetermined duration over a wireless communications channel and including multiple tones used for a plurality of OFDM symbol transmission time periods;

a selection module for selecting a first maximum rate option indicator value of a first type and including a first number of bits 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; 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, and 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.

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

first type assignment generation means for generating a first segment assignment signal assigning a first communications segment to a wireless terminal, the first segment assignment signal including a first maximum uplink rate option indicator value having a first number of bits and indicating a first maximum up link rate option corresponding to a plurality of rate options available to the wireless terminal in determining an actual uplink transmission rate to be used when transmitting into the first communications segment;

second type assignment generation means for generating a second segment assignment signal assigning a second communications segment to said wireless terminal, the second segment assignment signal including a second maximum uplink rate option indicator value, said second maximum unlink rate option indicator value having a second number of bits which is more than said first number of bits and indicating a second maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the second communications segment; and

transmitter means for transmitting assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration over a wireless communications channel, said transmitter means being configured to transmit said first assignment signal to said wireless terminal over a first wireless assignment channel and transmit said second assignment signal to said wireless terminal over a second wireless assignment channel.

22. The base station of claim 21, wherein said transmitter means is an OFDM transmitter means;

and

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

23. The base station of claim 22, wherein said system supports a fixed number of different uplink rate options, the base station further comprising:

selection means for selecting said first maximum rate option indicator value, prior to transmitting said first segment assignment signal 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; and

wherein said first maximum unlink rate option indicator value is a single bit value.

24. A device comprising a processor configured to control a base station in a communications system to transmit assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration, the processor being configured to control said base station to:

generate a first segment assignment signal assigning a first communications segment to a wireless terminal, the first segment assignment signal including a first maximum uplink rate option indicator value having a first number of bits and indicating a first maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the first communications segment;

transmit said first segment assignment signal to the wireless terminal over a first wireless assignment channel;

generate a second segment assignment signal assigning a second communications segment to said wireless terminal, the second segment assignment signal including a second maximum uplink rate option indicator value, said second maximum uplink rate option indicator value having a second number of bits which is more than said first number of bits and indicating a second maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the second communications segment; and

transmit the second segment assignment signal to said wireless terminal over a second wireless assignment channel.

25. The device of claim 24, wherein said communications segments are OFDM communications segments including multiple tones used for a plurality of OFDM symbol transmission time periods.

26. The device of claim 25, wherein said system supports a fixed number of different uplink rate options, the processor being further configured to control said base station to:

select said first maximum rate option indicator value, prior to transmitting said first segment assignment signal, 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; and

wherein said first maximum uplink rate option indicator value is a single bit value.

27. A machine readable medium embodying machine executable instructions for controlling a base station in a communications system to transmit assignment information indicating assignment of uplink communications segments, each segment having a predetermined duration, the machine readable medium comprising:

instructions for causing the base station to generate a first segment assignment signal assigning a first communications segment to a wireless terminal, the first segment assignment signal including a first maximum uplink rate option indicator value having a first number of bits and indicating a first maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the first communications segment;

instructions for causing the base station to transmit said first segment assignment signal to the wireless terminal over a first wireless assignment channel;

instructions for causing the base station to generate a second segment assignment signal assigning a second communications segment to said wireless terminal, the second segment assignment signal including a second maximum uplink rate option indicator value, said second maximum uplink rate option indicator value having a second number of bits which is more than said first number of bits and indicating a second maximum uplink rate option corresponding to a plurality of rate options available to the wireless terminal in determining the actual uplink transmission rate to be used when transmitting in the second communications segment; and

instructions for causing the base station to transmit the second segment assignment signal to said wireless terminal over a second wireless assignment channel.

28. The machine readable medium of claim 27, wherein said communications segments are OFDM communications segments including multiple tones used for a plurality of OFDM symbol transmission time periods.

29. The machine readable medium of claim 28, wherein said system supports a fixed number of different uplink rate options, and wherein the machine readable medium further comprises:

instructions for causing the base station to select said first maximum rate option indicator value, prior to transmitting said first segment assignment signal, 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; and

wherein said first maximum uplink rate option indicator value is a single bit value.