Dynamic TDMA system for TV white space MIMO wireless

• US 8,699,411 B1
• Filed: 09/30/2009
• Issued: 04/15/2014
• Est. Priority Date: 09/30/2009
• Status: Expired due to Fees

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Gossett, Carroll Philip, Yuan, Yuan, Yu, Kevin C., Koukoumidis, Emmanouil, Jiang, Xiaofang, Gunter, Michial Allen
• Primary Examiner(s): BEHARRY, NOEL R
• Application Number:
  US12/570,741
• Time in Patent Office: 1,658 Days
• Field of Search: 370/328
• US Class Current: 370/328
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04W 72/00 Local resource management
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/52 based on load

Abstract

A method may include identifying a repeating frame structure for communication between a MIMO base station and one or more wireless devices, the frame structure including a plurality of slots, with each slot including an uplink portion and a downlink portion, and each uplink portion and downlink portion comprising a plurality of sub-slots, receiving, at the wireless base station, an identification of a first wireless device of the one or more wireless devices, assigning to the first wireless device, a sub-slot in an uplink portion of a static slot in the frame structure, communicating, to the first wireless device, information from which the first wireless device can identify the sub-slot, and communicating with the one or more wireless devices by associating data in the first sub-slot with the first wireless device.

Claims

1. A method of coordinating communications between a wireless MIMO base station and one or more wireless devices, comprising:

identifying a repeating frame structure for communication between the MIMO base station and the one or more wireless devices, the frame structure including a plurality of slots, with each slot including an uplink portion and a downlink portion, and each uplink portion and downlink portion comprising a plurality of sub-slots;

receiving, at the MIMO base station, an identification of a first wireless device of the one or more wireless devices;

assigning to the first wireless device, to the exclusion of others of the one or more wireless devices, a sub-slot in an uplink portion of a static slot in the frame structure, wherein

each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned;

communicating, to the first wireless device, information from which the first wireless device can identify the assigned sub-slot;

communicating with the one or more wireless devices by associating data in the assigned sub-slot with the first wireless device, and allocating one or more sub-slots within a plurality of dynamic slots in the frame structure to the first wireless device by determining information relating to a traffic load for the first wireless device, wherein the static slot is interleaved in the frame with the plurality of dynamic slots; and

communicating with each of the one or more wireless devices such that, while the one or more wireless devices are associated with the MIMO base station, each of the one or more wireless devices is assigned at least one sub-slot in an uplink portion of a static slot and at least one sub-slot in a downlink portion of a static slot in each repetition of the frame structure.

2. The method of claim 1, further comprising communicating, via a single antenna, with a plurality of wireless communication devices that includes the one or more wireless devices, by allocating portions of the static slot that comprises the sub-slot assigned to the first wireless device to each of the plurality of wireless communication devices.

3. The method of claim 2, further comprising communicating with a plurality of groups of wireless communication devices using a plurality of antennas, each antenna communicating with a plurality of wireless communication devices by allocating portions of respective slots for each antenna to each of a plurality of wireless communication devices that communicate via each antenna.

4. The method of claim 1, further comprising receiving, from the first wireless device, a pilot signal and using the pilot signal to determine propagation delay by identifying a difference between an expected signal arrival time and an actual signal arrival time for the pilot signal.

5. The method of claim 4, further comprising transmitting to the client device information corresponding the determined propagation delay to allow the client device to adjust timing of a data transmission to correct for the propagation delay.

6. The method of claim 1, wherein assigning to the first wireless device a sub-slot comprises using an offset seed value to compute a sub-slot, and further comprising transmitting the seed value to the first wireless device to permit the first wireless device to identify a sub-slot that matches the assigned sub-slot.

7. The method of claim 1, further comprising allocating one or more sub-slots in dynamic slots in the frame during communication with the first wireless device by identifying a dynamic sub-slot request and allocating the one or more sub-slots in dynamic slots to the first wireless device based on a bandwidth requirement indicated by the dynamic sub-slot request.

8. The method of claim 7, wherein a number of dynamic sub-slots allocated to the first wireless device is at least partially dependent on a signal quality measured for communications between the first wireless device and the base station.

9. The method of claim 8, wherein devices of the one or more communication devices having a high signal quality are allocated more sub-slots than devices of the one or more communication devices having a low signal quality.

10. The method of claim 8, wherein the signal quality is measured by one or more factors selected from a group consisting of average transmission rate, average signal-to-noise ratio, average packet loss rate, and average channel capacity.

11. The method of claim 1, wherein the repeating frame structure defines one or more guard sub-slots at the leading edge or trailing edge of one or more portions of each slot, wherein the MIMO base station does not transmit data during the guard sub-slots.

12. The method of claim 1, further comprising receiving, at the wireless MIMO base station, identifications from a plurality of wireless devices, assigning at least one sub-slot in one or more static slots to each of the wireless devices, and communicating with each of the wireless devices by associating, with each wireless device, data in a sub-slot of a static slot assigned to the wireless device, and allocating sub-slots, in addition to the sub-slots in the static slots, to the wireless devices by determining traffic loads for the wireless devices, wherein at least some of the static slots are interleaved in the frame with dynamic slots that include the additional sub-slots.

13. The method of claim 12, wherein each static slot is separated from each adjacent static slot by at least one slot that is not a static slot.

14. The method of claim 12, further comprising allocating sub-slots within the plurality of slots so as to spread transmissions by the client devices across the slots.

15. The method of claim 1, wherein a number of assigned sub-slots within uplink portions of the static slots equals the number of wireless devices communicating with the base station.

16. The method of claim 1, wherein assigning to the first wireless device a sub-slot in an uplink portion of a static slot in the frame structure comprises:

determining the sub-slot to assign to the first wireless device based on (i) a total number of wireless devices in communication with the MIMO base station, (ii) a number of sub-slots in a static slot, and (iii) a number of antennas of the MIMO base station, the MIMO base station having a plurality of antennas.

17. The method of claim 1, wherein assigning to the first wireless device a sub-slot in an uplink portion of a static slot in the frame structure comprises:

determining, from among a plurality of antennas of the MIMO base station, an antenna of the MIMO base station to assign to the first wireless device based on (i) a total number of wireless devices in communication with the MIMO base station, (ii) a number of sub-slots in a static slot, and (iii) a number of antennas of the MIMO base station.

18. The method of claim 1, further comprising allocating, to the first wireless device, one or more sub-slots within a plurality of dynamic slots in the frame structure based at least in part on a measure of efficiency with which wireless channel conditions permit data transfer between the base station and the first wireless device.

19. A system for coordinating communications between a base station and one or more wireless devices, comprising:

one or more encoders in a communications base station programmed to define a repeating frame structure for communication between the base station and the one or more wireless devices, the frame structure including a plurality of slots, with each slot including an uplink portion and a downlink portion, and each uplink portion and downlink portion comprising a plurality of sub-slots; and

a network processor associated with the base station and programmed to (i) receive an identification of a first wireless device of the one or more wireless devices, (ii) assign to the first wireless device, to the exclusion of others of the one or more wireless devices, a sub-slot in an uplink portion of a static slot in the frame structure, (iii) communicate, to the first wireless device, information from which the first wireless device can identify the sub-slot; and

(iv) communicate with the one or more wireless devices by associating data in the assigned sub-slot with the first wireless device, and allocating one or more sub-slots within a plurality of dynamic slots in the frame structure to the first wireless device by determining information relating to a traffic load for the first wireless device, wherein the static slot is interleaved in the frame with the plurality of dynamic slots,

wherein each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned,

wherein, while the one or more wireless devices are associated with the MIMO base station, each of the one or more wireless devices is assigned at least one sub-slot in an uplink portion of a static slot and at least one sub-slot in a downlink portion of a static slot in each repetition of the frame structure.

20. The system of claim 19, wherein the base station is configured to communicate, via a single antenna, with a plurality of wireless communication devices that includes the one or more wireless devices, by allocating portions of the static slot that comprises the sub-slot assigned to the first wireless device to each of the plurality of wireless communication devices.

21. The system of claim 20, wherein the base station is further configured to communicate with a plurality of groups of wireless communication devices using a plurality of antennas, each antenna communicating with a plurality of wireless communication devices by allocating portions of respective slots for each antenna to each of a plurality of wireless communication devices that communicate via each antenna.

22. The system of claim 19, wherein the base station is further configured to receive, from the first wireless device, a pilot signal and use the pilot signal to determine propagation delay by identifying a difference between an expected signal arrival time and an actual signal arrival time for the pilot signal.

23. The system of claim 22, wherein the base station is further programmed to transmit to the client device information corresponding the determined propagation delay to allow the client device to adjust timing of a data transmission to correct for the propagation delay.

24. The system of claim 19, wherein the base station is further programmed to assign to the first wireless device a sub-slot comprises using an offset seed value to compute a sub-slot, and to transmit the seed value to the first wireless device to permit the first wireless device to identify a sub-slot that matches the assigned sub-slot.

25. The system of claim 19, wherein the network processor is further programmed to allocate one or more sub-slots in dynamic slots in the frame during communication with the first wireless device by identifying a dynamic sub-slot request and to allocate the one or more sub-slots in dynamic slots to the first wireless device based on a bandwidth requirement indicated by the dynamic sub-slot request.

26. The system of claim 19, wherein the base station is further configured to receive identifications from a plurality of wireless devices, assign at least one sub-slot in one or more static slots to each of the wireless devices, and communicate with each of the wireless devices by associating, with each wireless device, data in a sub-slot of a static slot assigned to the wireless device, and allocate sub-slots, in addition to the sub-slots in the static slots, to the wireless devices by determining traffic loads for the wireless devices, wherein at least some of the static slots are interleaved in the frame with dynamic slots that include the additional sub-slots.

27. The system of claim 25, wherein each static slot is separated from each adjacent static slot by at least one slot that is not a static slot.

28. The system of claim 19, wherein the network processor is further programmed to allocate sub-slots within the plurality of slots so as to spread transmissions by the client devices across the slots.

29. A system for coordinating communications between a base station and one or more wireless devices, comprising:

one or more encoders in a communications base station programmed to define a repeating frame structure for communication between the base station and the one or more wireless devices, the frame structure including a plurality of slots, with each slot including an uplink portion and a downlink portion, and each uplink portion and downlink portion comprising a plurality of sub-slots; and

means for assigning to a wireless device, to the exclusion of other wireless devices, a sub-slot in an uplink portion of a static slot in the frame structure, and to communicate to the wireless device information from which the wireless device can identify the sub-slot,

wherein each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned, and

wherein, while the one or more wireless devices are associated with the MIMO base station, each of the one or more wireless devices is assigned at least one sub-slot in an uplink portion of a static slot and at least one sub-slot in a downlink portion of a static slot in each repetition of the frame structure.

30. A method of coordinating communications between a wireless MIMO base station and one or more wireless devices, comprising:

identifying a repeating frame structure for communication between the MIMO base station and the one or more wireless devices, the frame structure including a plurality of slots that each comprise a plurality of sub-slots, the frame structure having uplink portions and downlink portions;

receiving, at the MIMO base station, an identification of a first wireless device of the one or more wireless devices;

assigning to the first wireless device, to the exclusion of others of the one or more wireless devices, a sub-slot in an uplink portion of a static slot in the frame structure, wherein

each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned;

communicating, to the first wireless device, information from which the first wireless device can identify the sub-slot;

communicating with the one or more wireless devices by associating data in the assigned sub-slot with the first wireless device; and

allocating, to the first wireless device, one or more sub-slots within a plurality of dynamic slots in the frame structure based on (i) information relating to a traffic load for the first wireless device and (ii) a signal quality for communications between the first wireless device and the base station, the signal quality being measured by one or more factors selected from a group consisting of average transmission rate, average signal-to-noise ratio, average packet loss rate, and average channel capacity.

31. A method of coordinating communications between a wireless MIMO base station and one or more wireless devices, comprising:

identifying a repeating frame structure for communication between the MIMO base station and the one or more wireless devices, the MIMO base station having a plurality of antennas, the frame structure including a plurality of slots that each comprise a plurality of sub-slots, the frame structure having uplink portions and downlink portions;

receiving, at the MIMO base station, an identification of a first wireless device of the one or more wireless devices;

determining a sub-slot in an uplink portion of a static slot in the frame structure to assign to the first wireless device based on (i) a total number of wireless devices in communication with the MIMO base station, (ii) a number of sub-slots in a static slot, and (iii) a number of antennas of the MIMO base station;

assigning the determined sub-slot to the first wireless device, to the exclusion of others of the one or more wireless devices, wherein

each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned;

communicating, to the first wireless device, information from which the first wireless device can identify the sub-slot; and

communicating with the one or more wireless devices by associating data in the assigned sub-slot with the first wireless device, and allocating one or more sub-slots within a plurality of dynamic slots in the frame structure to the first wireless device by determining information relating to a traffic load for the first wireless device.

32. A method of coordinating communications between a wireless MIMO base station and one or more wireless devices, comprising:

identifying a repeating frame structure for communication between the MIMO base station and the one or more wireless devices, the frame structure including a plurality of slots that each comprise a plurality of sub-slots, the frame structure having uplink portions and downlink portions;

receiving, at the MIMO base station, an identification of a first wireless device of the one or more wireless devices;

determining, from among a plurality of antennas of the MIMO base station, an antenna of the MIMO base station to use for communications with the first wireless device based on (i) a total number of wireless devices in communication with the MIMO base station, (ii) a number of sub-slots in a static slot, and (iii) a number of antennas of the MIMO base station;

assigning the determined antenna of the MIMO base station to the first wireless device;

assigning to the first wireless device, to the exclusion of others of the one or more wireless devices, a sub-slot in an uplink portion of a static slot in the frame structure, wherein

each sub-slot in the uplink portion that is assigned to a wireless device is assigned to a wireless device that differs from the wireless devices to which each of the other sub-slots in the uplink portion are assigned;

communicating, to the first wireless device, information from which the first wireless device can identify the sub-slot; and

communicating with the one or more wireless devices by associating data in the assigned sub-slot with the first wireless device and by communicating with the first wireless device using the determined antenna, and allocating one or more sub-slots within a plurality of dynamic slots in the frame structure to the first wireless device by determining information relating to a traffic load for the first wireless device.