Forward-link scheduling in a wireless communication system during soft and softer handoff

• US 6,760,587 B2
• Filed: 02/23/2001
• Issued: 07/06/2004
• Est. Priority Date: 02/23/2001
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bao, Gang, Holtzman, Jack M.
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US09/792,518
• Publication Number:
  US 20020160783A1
• Time in Patent Office: 1,229 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/442, 455/443, 455/445, 455/403, 455/422, 455/69, 455/522, 455/67.1, 455/517, 455/423, 455/424, 455/425, 455/561, 455/562, 370/331, 370/332
• US Class Current: 455/436
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/223 predicting future states of the transmission
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/26 using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

A method and apparatus for scheduling transmit rates and power levels for data in conjunction with a voice-data communication during conditions of soft and softer handoff. During conditions of no handoff, or hard handoff, an algorithm selects a slot reflecting a favored power level and transmission rate for transmitting the non-voice data on a supplemental channel. The slot is selected based upon the transmission power levels for voice-data transmitted by a base station to a remote station on a fundamental channel. The algorithm applies to softer handoff using information from all the sectors of a base station involved in the softer handoff. During soft handoff, instead of scheduling forward link transmission based on recent power and rate, or C/I information, data is continuously transmitted to the user at a power level based on average required power.

Claims

1. A method of scheduling transmit rates and transmit power levels of data users in a wireless communication system during softer handoff, comprising:

transmitting signals between a base station having at least two sectors and a remote station via at least one first channel per sector, wherein the transmitted signals comprise voice-data;

measuring at the base station a ratio of transmission power levels for the voice-data transmitted via the at least one first channel per sector;

determining a historical profile for the ratio of transmission power levels; and

using the historical profile for the ratio of transmission power levels to select a second channel transmission power level and data rate for transmitting additional data.

2. The method in accordance with claim 1, further comprising:

measuring at the remote station transmission metrics reflecting the quality of voice-data signals received from the base station sectors;

messaging from the remote station to the base station any change or non-change in the voice-data quality; and

adjusting or not adjusting the transmission power in consideration of said messages for voice-data transmitted by the base station sectors.

3. A signal bearing medium tangibly embodying a program of machine-readable instructions executable by a processor to perform a method for predicting a favored slot for transmitting data in a wireless communication system during softer handoff, the instructions comprising:

transmitting signals containing voice-data between a base station having at least two sectors and a remote station;

measuring at the base station a ratio of transmission power levels for voice-data transmitted via the at least one first channel per sector;

determining a historical profile for the ratio of transmission power levels; and

using the historical profile of the ratio of transmission power levels to select a second channel transmission power level and data rate for transmitting additional data.

4. The signal-bearing medium in accordance with claim 3, wherein the instructions further comprise:

measuring at the remote station transmission metrics reflecting the quality of voice-data signals received from the sectors of the base station;

messaging from the remote station to the base station any change or non-change in the voice-data quality; and

adjusting or not adjusting the transmission power of the sectors in consideration of said messages for voice-data transmitted by the base station.

5. The signal-bearing medium in accordance with claim 3, wherein the instructions further comprise:

measuring at the remote station transmission metrics reflecting the quality of voice-data signals received from the base station;

messaging from the remote station to the base station any change or non-change in the voice-data quality; and

adjusting or not adjusting the transmission power in consideration of said messages for voice-data transmitted by the base station.

6. A base station for scheduling transmit rates and transmit power levels of data users in a wireless communication system during softer handoff, the base station having at least two sectors communicatively coupled to a remote station, wherein the base station may communicate with the remote station using more than one channel, the base station comprising:

a transmitter, the transmitter capable of transmitting voice and non-voice data signals between a base station and a remote station; and

a processor communicatively coupled to the transmitter and capable of executing instructions to;

measure at the base station transmission power levels for voice-data transmitted to the remote station via at least one first channel per sector;

determine a dynamic transmission power level for transmissions made via the at least one first channel per sector; and

use the dynamic transmission power level to select a second channel transmission slot for transmitting additional data to the remote station.

7. A method of scheduling transmit rates and transmit power levels of data users in a wireless communication system, comprising:

transmitting signals between a base station and a remote station via at least one first channel, wherein the transmitted signals comprise voice-data;

measuring at the base station transmission power levels for the voice-data transmitted via the at least one first channel;

determining a historical profile for the transmission power levels;

using the historical profile for the transmission power levels to select a second channel transmission power level and data rate for transmitting additional data;

selecting a soft handoff power level and transmission rate based on average required power; and

transmitting continuously to the user at the soft handoff power level and transmission rate during soft handoff.

8. The method of claim 7, further comprising:

measuring at the remote station transmission metrics reflecting the quality of voice-data signals received from the base station;

messaging from the remote station to the base station any change or non-change in the voice-data quality; and

adjusting or not adjusting the transmission power in consideration of said messages for voice-data transmitted by the base station.

9. A signal bearing medium tangibly embodying a program of machine-readable instructions executable by a processor to perform a method for scheduling transmit rates and transmit power levels of data users in a wireless communication system, the instructions comprising:

transmitting signals containing voice-data between a base station and a remote station;

measuring at the base station transmission power levels for voice-data transmitted via at least one first channel;

determining a historical profile for the transmission power levels;

using the historical profile of the transmission power levels to select a second channel transmission power level and data rate for transmitting additional data;

selecting a soft handoff power level and transmission rate based on average required power; and

transmitting continuously to the user at the soft handoff power level and transmission rate during soft handoff.

10. A base station for scheduling transmit rates and transmit power levels of data users in a wireless communication system, the base station communicatively coupled to a remote station, wherein the base station may communicate with the remote station using more than one channel, the base station comprising:

a transmitter, the transmitter capable of transmitting voice and non-voice data signals between a base station and a remote station; and

a processor communicatively coupled to the transmitter and capable of executing instructions to;

measure at the base station transmission power levels for voice-data transmitted to the remote station via at least one first channel;

determine a dynamic transmission power level for transmissions made via the at least one first channel;

use the dynamic transmission power level to select a second channel transmission slot for transmitting additional data to the remote station;

select a soft handoff power level and transmission rate based on average required power; and

transmit continuously to the user at the soft handoff power level and transmission rate during soft handoff.