VARIED TRANSMISSION TIME INTERVALS FOR WIRELESS COMMUNICATION SYSTEM

• US 20090213750A1
• Filed: 02/19/2009
• Published: 08/27/2009
• Est. Priority Date: 08/24/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Gorokhov, Alexei, Khandekar, Aamod, Teague, Edward H.
• Granted Patent: US 8,787,347 B2
• Time in Patent Office: Days
• US Class Current: 370/253
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Embodiments describe a varied transmission time interval in wireless communication system. According to some embodiments is a method for assigning a transmission time interval. The method can include measuring a channel condition and/or a data rate of packet communicated by at least one wireless device. Based in part on the data rate and/or channel condition information, a determination can be made whether to schedule a long transmission time interval or a short transmission time interval to the packet. A long transmission time interval can be scheduled if the channel condition is poor and/or there is a low data rate. A short transmission time interval can be scheduled if the channel condition is good and/or the data rate is high or fast. The method can be repeated for multiple wireless devices. Also included is an alternative interlacing structure that supports both long transmission time intervals and short transmission time intervals.

Claims

1. A method for assigning transmission time intervals, comprising:

measuring a channel condition based on at least one packet communicated by at least one wireless device;

determining whether to schedule a long transmission time interval or a short transmission time interval for an encoded packet based on the measured channel condition; and

indicating an interlacing structure from at least one of a plurality of interlacing structures for the encoded packet, wherein the interlace structure determines a retransmission interval.

2. The method of claim 1, wherein the retransmission interval is a hybrid automatic repeat request (HARQ) interval.

3. The method of claim 1, further comprising:

scheduling a long transmission time interval if the channel condition is poor and there is a low data rate, or scheduling a short transmission time interval if the channel condition is good and there is a high data rate.

4. The method of claim 3, wherein the interlacing structure for the encoded packet comprises an interlace of three if the channel condition is poor, or the interlacing structure for the encoded packet comprises an interlace of six if the channel condition is good.

5. The method of claim 1, further comprising:

issuing a channel assignment message to be transmitted on a forward-link.

6. The method of claim 5, further comprising:

adding an extra bit to a forward link assignment message (FLAM) or a reverse link assignment message (RLAM) to indicate the interlacing structure for the encoded packet.

7. A processor that executes instructions for assigning one of multiple transmission time intervals to a user device, comprising:

an optimizer that analyzes a condition of a wireless data packet and a data rate of the wireless data packet; and

a scheduler that schedules a transmission time interval for an encoded packet, wherein the transmission time interval is determined to be either one of a long transmission time interval or a short transmission time interval based on the optimizer wireless data packet analysis, and that indicates an interlacing structure from at least one of a plurality of interlacing structures for the encoded packet, wherein the interlace structure determines a retransmission interval.

8. The processor of claim 7, wherein the retransmission interval is a hybrid automatic repeat request (HARQ) interval.

9. An apparatus for scheduling wireless user devices to different transmission time intervals, comprising:

means for ascertaining a channel condition for each user device;

means for indicating an interlacing structure from at least one of a plurality of interlacing structures for each user device based on the channel condition, wherein the interlace structure determines a retransmission interval; and

means for scheduling each user device a respective transmission time interval based on the channel condition.

10. The apparatus of claim 9, the user device is scheduled either a short transmission time interval or a long transmission time interval.

11. The apparatus of claim 9, wherein the interlacing structure for the encoded packet comprises an interlace of three if the channel condition is poor, or the interlacing structure for the encoded packet comprises an interlace of six if the channel condition is good.

12. The apparatus of claim 9, wherein the means for indicating an interlacing structure comprises means for issuing a channel assignment message to be transmitted on a forward-link.

13. The apparatus of claim 12, wherein the channel assignment message is transmitted on the forward-link prior to or at substantially the same time as a forward-link packet transmission.

14. The apparatus of claim 12, wherein the channel assignment message is transmitted on the forward-link prior to a reverse-link packet transmission.

15. The apparatus of claim 9, wherein the indicated interlacing structure determines a forward link or reverse link transmission interval.

16. The apparatus of claim 9, wherein the indicated interlacing structure for a forward link and a reverse link interface is the same, and produces the same transmission and retransmission delays on each of the forward link and the reverse link interface.

17. A Computer program product, comprising:

computer-readable medium comprising;

code for causing a computer to detect a packet channel condition;

code for causing a computer to ascertain a packet data rate;

code for causing a computer to schedule a long transmission time interval or a short transmission time interval to an encoded packet based in part on the detected channel condition and the ascertained data rate; and

code for causing a computer to indicate an interlacing structure from at least one of a plurality of interlacing structures for the encoded packet, wherein the interlace structure determines a retransmission interval.