Transmitter time adjustments for groups of receivers

Patent metadata

Field	Value
Publication number	US-10554465-B2
Application number	US-201916415111-A
Country	US
Kind code	B2
Filing date	May 17, 2019
Priority date	Dec 27, 2006
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

A method and system for achieving a link budget improvement in a diverse OFDM radio system by addressing the timing misalignment issue that can occur due to the differences in propagation time in signals between mobile stations and Radio Access Nodes. Timing misalignment is shared or split between the primary path to a primary Radio Access Node and a diverse path to a diverse Radio Access Node. The relative timing offsets between mobile stations are adjusted, the mobile stations are grouped into zones using a variety of different grouping techniques, and the transmission for each mobile station is scheduled, using one or more of a variety of scheduling techniques.

First claim

What is claimed is:

1. A method for operating a transmitter device to mitigate misalignment of transmissions, the method comprising:
performing, by the transmitter device:
generating first transmissions to each of a plurality of receiver device groups, wherein at least a first receiver device group of the plurality of receiver device groups comprises two or more receiver devices;
receiving respective time adjustments from a base station for use in generating second transmissions to each of the plurality of receiver device groups, wherein said respective time adjustments are based at least in part on a misalignment related to the first transmissions; and
generating second transmissions to each of the plurality of receiver device groups using the respective time adjustments, wherein, for the first receiver device group of the plurality of receiver device groups, first time adjustments of the respective time adjustments cause the second transmissions for the transmitter device and at least one other transmitter device to arrive within a cyclic prefix or at substantially the same time at each receiver device of the first receiver device group,

wherein the transmitter device and the receiver devices are configured to communicate using orthogonal frequency division multiplexing (OFDM)-based communication.

2. The method of claim 1 , wherein the transmissions to each of the plurality of receiver device groups are scheduled using different time intervals.

3. The method of claim 1 , wherein the transmissions to each of the plurality of receiver device groups are scheduled using frequency multiplexing.

4. The method of claim 1 , wherein the receiver devices are fixed remote station receivers.

5. The method of claim 1 , wherein the transmitter device is a user equipment (UE) device.

6. The method of claim 1 , further comprising:
receiving updates to the respective time adjustments, wherein said updating enables synchronization of subsequent transmissions to be maintained in spite of movements of the transmitter device.

7. A transmitter device, comprising:
a radio; and
a processor, wherein the transmitter device is configured to:
generate first transmissions to each of a plurality of receiver device groups, wherein at least a first receiver device group of the plurality of receiver device groups comprises two or more receiver devices;
receive respective time adjustments from a base station for use in generating second transmissions to each of the plurality of receiver device groups, wherein said respective time adjustments are based at least in part on a misalignment related to the first transmissions; and
generate second transmissions to each of the plurality of receiver device groups using the respective time adjustments, wherein, for the first receiver device group of the plurality of receiver device groups, first time adjustments of the respective time adjustments cause the second transmissions for the transmitter device and at least one other transmitter device to arrive within a cyclic prefix or at substantially the same time at each receiver device of the first receiver device group,
wherein the transmitter device and the receiver devices are configured to communicate using orthogonal frequency division multiplexing (OFDM)-based communication.

8. The transmitter device of claim 7 , wherein the transmissions to each of the plurality of receiver device groups are scheduled using different time intervals.

9. The transmitter device of claim 7 , wherein the transmissions to each of the plurality of receiver device groups are scheduled using frequency multiplexing.

10. The transmitter device of claim 7 , wherein the receiver devices are fixed remote station receivers.

11. The transmitter device of claim 7 , wherein the transmitter device is a user equipment (UE) device.

12. The transmitter device of claim 7 , further comprising:
receiving updates to the respective time adjustments, wherein said updating enables synchronization of subsequent transmissions to be maintained in spite of movements of the transmitter device.

13. A non-transitory computer-readable memory medium storing program instructions which, when executed by a processor of a transmitter device, cause the transmitter device to:
generate first transmissions to each of a plurality of receiver device groups, wherein at least a first receiver device group of the plurality of receiver device groups comprises two or more receiver devices;
receive respective time adjustments from a base station for use in generating second transmissions to each of the plurality of receiver device groups, wherein said respective time adjustments are based at least in part on a misalignment related to the first transmissions; and
generate second transmissions to each of the plurality of receiver device groups using the respective time adjustments, wherein, for the first receiver device group of the plurality of receiver device groups, first time adjustments of the respective time adjustments cause the second transmissions for the transmitter device and at least one other transmitter device to arrive within a cyclic prefix or at substantially the same time at each receiver device of the first receiver device group,
wherein the transmitter device and the receiver devices are configured to communicate using orthogonal frequency division multiplexing (OFDM)-based communication.

14. The non-transitory computer-readable memory medium of claim 13 , wherein the receiver devices are fixed remote station receivers, and wherein the transmitter device is a user equipment (UE) device.

15. The non-transitory computer-readable memory medium of claim 13 , wherein the program instructions are further executable to cause the transmitter device to:
receive updates to the respective time adjustments, wherein said updating enables synchronization of subsequent transmissions to be maintained in spite of movements of the transmitter device.

Assignees

• Apple Inc

Inventors

• Smith Adrian
• Li Xiao-Dong
• Steer David
• Au Kelvin Kar-Kin
• Novak Robert
• Earnshaw Mark

Classifications

• H04L27/2646 Primary

  using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length · CPC title

• H04W56/0045

  compensating for timing error by altering transmission time · CPC title

• H04B7/18534

  for enhancing link reliablility, e.g. satellites diversity · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04L5/023 Primary

  Multiplexing of multicarrier modulation signals, e.g. multi-user orthogonal frequency division multiple access [OFDMA] (multicarrier modulation H04L27/2601) · CPC title