Method and system for soft handoff in mobile broadband systems

• US 9,363,729 B2
• Filed: 05/13/2013
• Issued: 06/07/2016
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Senarath, Nimal, Gage, Bill, Periyalwar, Shalini, Tong, Wen
• Primary Examiner(s): Beyen, Zewdu A
• Application Number:
  US13/893,144
• Publication Number:
  US 20130250858A1
• Time in Patent Office: 1,121 Days
• Field of Search: 370/331, 370/329, 370/330, 370/338
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

The present invention provides a method and system for facilitating efficient handoff and data throughput in mobile broadband communication systems. Methods implemented by a system constructed in accordance with the principles of the present invention include selectively enabled soft handoff, performing Layer 2 bearer functions at the base station and using the mobile device to coordinate soft handoff and interference avoidance without the need for a centralized coordination function.

Claims

1. A method of receiving data from one or more station transceiver systems, comprising:

at a mobile device;

communicating with a first station transceiver system;

receiving pilots transmitted by a first set of station transceiver systems, wherein the first set of station transceiver systems comprises a measurement set of two or more station transceiver systems including the first station transceiver system, and wherein a second set of station transceiver systems comprises an active set, wherein the active set comprises two or more station transceiver systems including the first station transceiver system, and is a proper subset of the measurement set;

measuring radio link conditions based on the received pilots from the first set of station transceiver systems;

determining at least a first indication associated with a modulation and coding scheme based on the radio link conditions;

determining at least a second indication associated with an antenna processing option based on the radio link conditions, wherein one or more of the first and second indications are determined based on radio link conditions from at least a pilot transmitted by a second station transceiver system, wherein the second station transceiver system is different from the first station transceiver system;

reporting at least the first and second indication;

receiving a plurality of data transmissions from a plurality of third sets of station transceiver systems, wherein each data transmission of the plurality of data transmissions is received from a respective third set of station transceiver systems of the plurality of third sets of station transceiver systems, wherein each of the third sets is a subset of the station transceiver systems of the second set and comprises at least one station transceiver system of the second set, wherein the mobile device is configured to receive data transmissions of the plurality of data transmissions from respective different ones of the third sets of station transceiver systems contemporaneously, wherein a control channel signal related to each data transmission provides an indication related to at least a member of the third set.

2. The method of claim 1, wherein the indication related to at a member of the third set indicates the data transmission is associated with one station transceiver system.

3. The method of claim 1, wherein the indication related to at a member of the third set indicates a transmission from multiple station transceiver system.

4. The method of claim 1, wherein the plurality of data transmissions have been multi-cast to the at least the third set of transceiver systems as higher layer packets.

5. The method of claim 4, wherein the higher layer packets are internet protocol packets.

6. The method of claim 1, wherein the plurality of data transmissions have been multi-cast to the at least the third set of transceiver systems as MAC packets.

7. The method of claim 1, wherein determining the at least a first indication associated with a modulation and coding scheme further comprises determining the at least a first indication based on a combination of carrier to interference ratios of the received pilots.

8. The method of claim 1, further comprising the mobile device managing adding and dropping station transceiver systems to the second set of station transceiver systems.

9. The method of claim 1, further comprising a network entity managing adding and dropping station transceiver systems to the second set of station transceiver systems.

10. The method of claim 1, wherein receiving the plurality of data transmissions is based on a resources request transmitted by the mobile device.

11. A broadband cellular communication system, comprising:

a first set of station transceiver systems configured to transmit pilots to at least a first mobile station, wherein the first set of station transceiver systems comprises a measurement set of two or more station transceiver systems including a first station transceiver system; and

a second set of station transceiver systems, wherein the second set comprises an active set, wherein the active set comprises two or more station transceiver systems including the first station transceiver system, and is a proper subset of the measurement set;

wherein one or more station transceiver systems of the second set are configured to;

receive one or more indications from at least the first mobile station, wherein a first indication is associated with a modulation and coding scheme based on the radio link conditions, wherein a second indication is associated with an antenna processing option based on the radio link conditions, wherein one or more first and second indications are determined based on radio link conditions from at least a pilot transmitted by a second station transceiver system of the first set of station transceiver systems, wherein the second station transceiver system is different from the first station transceiver system;

transmit a control channel signal related to a data transmission providing an indication related to at least a member of a third set of station transceiver systems of a plurality of third sets of station transceiver systems, wherein each of the third sets is subset of the station transceiver systems of the second set, and comprises at least one station transceiver system of the second set; and

wherein each of the third sets of station transceiver systems is configured to;

transmit the data transmission to the mobile station based on the control channel indication, wherein the mobile station is configured to receive a plurality of data transmissions from respective different ones of the third sets of station transceiver systems contemporaneously.

12. The system of claim 11, wherein the indication related to at a member of the third set indicates the data transmission associated with one station transceiver system.

13. The system of claim 11, wherein the indication related to at a member of the third set indicates a transmission from multiple station transceiver system.

14. The system of claim 11, wherein the data transmission has been multi-cast to the at least the third set of transceiver systems as higher layer packets.

15. The system of claim 14, wherein the higher layer packets are IP packets.

16. The system of claim 11, wherein the data transmission has been multi-cast to the at least the third set of transceiver systems as MAC packets.

17. The system of claim 11, wherein the first indication is associated with a modulation and coding scheme based on a combination of carrier to interference ratios of the received pilots.

18. The system of claim 11, wherein the second set of station transceiver systems is managed by the first mobile station.

19. The system of claim 11, wherein a network entity is configured to manage adding and dropping station transceiver systems to the second set of station transceiver systems.

20. The system of claim 11, wherein the third set of transceiver systems is further configured to transit the data transmission based on a received resources request, wherein the resources request was transmitted by the first mobile station.