SYSTEMS, METHODS AND DEVICES FOR FLEXIBLE RETRANSMISSIONS

• US 20150327275A1
• Filed: 12/24/2014
• Published: 11/12/2015
• Est. Priority Date: 05/08/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel IP Corporation (Intel Corporation)
• Inventors: KWON, HWAN-JOON, HEO, YOUN HYOUNG, HAN, SEUNGHEE, FWU, JONG-KAE, HE, HONG
• Granted Patent: US 9,729,283 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1893 Physical mapping arrangements physical resource mapping in general H04L5/00
• CPC Class Codes: H04L 2001/0092 Error control systems characterised by the topology of the transmission link
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 28/082 among bearers or channels
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

A hybrid automatic repeat request (HARQ) process enables a retransmission to be sent on a carrier (or medium, set of frequencies, band, etc.) different from the carrier on which the previous transmissions (initial transmission and/or retransmissions) were sent. An enhanced HARQ process can improve system performance by aiding user throughput, system throughput, and delay performance by making retransmissions possible even when the unlicensed band is not available (e.g., when occupied by other RATs or the same RAT deployed by another operator). For example, a transmitter sends a subpacket in an unlicensed band. The receiver feeds back a NACK to the transmitter due to the packet decoding failure. If the medium is not idle, the transmitter sends the retransmission in another band or another channel that can be either a licensed band/channel or another unlicensed band/channel. The retransmission can be sent in multiple licensed and/or unlicensed bands/channels at the same time.

Claims

1. An enhanced node B (eNB) for cross-carrier retransmission comprising:

a first wireless transceiver configured for communication over a first set of frequencies;

a second wireless transceiver configured for communication over a second set of frequencies; and

a processor configured to;

send a transmission of data over a secondary component carrier within the first set of frequencies to a mobile device;

receive a message indicating an error receiving the transmission by the mobile device;

determine that the first set of frequencies are occupied by other transmissions; and

send a retransmission of the data over a primary component carrier within the second set of frequencies.

2. The eNB of claim 1, wherein the first set of frequencies is an unlicensed set of frequencies.

3. The eNB of claim 1, wherein the second set of frequencies is a licensed set of frequencies.

4. The eNB of claim 1, wherein the first set of frequencies is shared with another radio access technology (RAT).

5. The eNB of claim 1, further comprising:

a third wireless interface configured for transmissions over a third set of frequencies to the mobile device; and

wherein the processor is further configured to;

receive a second message indicating a second error receiving the retransmission;

determine that the first set of frequencies and the second set of frequencies are busy; and

send a second retransmission over the third set of frequencies.

6. The eNB of claim 1, wherein the processor is further configured to send a schedule indicating the retransmission of the transmission will be over the second set of frequencies.

7. The eNB of claim 1, wherein the first wireless interface is a long term evolution (LTE) interface and the second wireless interface is a WLAN interface.

8. A first base station for cross-carrier retransmission configured to:

communicate scheduling information for transmission of a subpacket to a user equipment (UE) over a secondary carrier using a second frequency band;

communicate the scheduling information for transmission of the subpacket to a second base station configured to communicate with the UE over the secondary carrier using the second frequency band;

receive a message from the UE indicating an error receiving the subpacket from the second base station;

determine that the second base station is unable to communicate with the UE over the secondary carrier using the second frequency band based at least in part on the second frequency band determined to be busy; and

send a retransmission of the subpacket to the UE over a primary carrier using a first frequency band.

9. The first base station of claim 8, wherein to determine that the second base station is unable to communicate with the UE over the secondary carrier using the second frequency band based at least in part on the second frequency band determined to be busy further comprises to receive a message from the second base station that the second frequency band is busy.

10. The first base station of claim 8, wherein to determine that the second base station is unable to communicate with the UE over the secondary carrier using the second frequency band based at least in part on the second frequency band determined to be busy further comprises to receive a message from the UE that the second frequency band is busy.

11. The first base station of claim 8, wherein the first base station is further configured to send scheduling information over the first frequency band.

12. The first base station of claim 8, wherein to communicate scheduling information for transmission of a subpacket to a user equipment (UE) further comprises to cause the second base station to send the scheduling information over the secondary carrier.

13. The first base station of claim 8, wherein to communicate scheduling information for transmission of a subpacket to a user equipment (UE) further comprises to cause a third base station to send the scheduling information in a third frequency band.

14. The first base station of claim 8, wherein the first base station is further configured to cause a third base station to send a second retransmission in a third frequency band.

15. The first base station of claim 8, wherein to determine that the second base station is unable to communicate with the UE further comprises to perform a listen before talk (LBT) protocol to determine that the second frequency band is busy.

16. A method of retransmission comprising:

sending data through a first physical downlink shared channel (PDSCH) transmission over a first frequency band to user equipment (UE);

receiving a hybrid automatic repeat request (HARD) message indicating an error in receiving the PDSCH transmission; and

sending the data through a second PDSCH transmission over a second frequency band.

17. The method of claim 16, further comprising retransmitting the data over the second wireless medium according to a semi-static configuration.

18. The method of claim 16, further comprising retransmitting the data over the second wireless medium according to a static configuration that dictates retransmission over the second wireless medium.

19. The method of claim 16, further comprising dynamically determining placement of a retransmission of the data over a wireless medium from a set of wireless mediums based at least in part on which wireless mediums from the set of wireless mediums are busy.

20. The method of claim 16, wherein sending the data over the second wireless medium further comprises sending the data over the second wireless medium and a third medium in parallel.

21. The method of claim 16, further comprising determining that the first wireless medium is busy.

22. The method of claim 16, further comprising sending a DCI format comprising a first component carrier (CC) indicator for an assigned transmission for a HARQ operation, a second CC indicator where an assigned PDSCH transmission is intended, an indicator of whether data is new or retransmitted, or a HARQ process number.