Carrier aggregation acknowledgement bits

Patent metadata

Field	Value
Publication number	US-9258741-B2
Application number	US-201313764718-A
Country	US
Kind code	B2
Filing date	Feb 11, 2013
Priority date	Aug 3, 2012
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Systems, methods, and user equipment can involve transmitting Acknowledgement/Negative Acknowledgement (ACK/NACK) bits for carrier aggregation between a first cell and a second cell in a User Equipment (UE). With the UE, for a sub-frame, a first number of ACK/NACK bits for the first cell can be compared with a second number of ACK/NACK bits for the second cell. If a first number of ACK/NACK bits for the first cell is less than a second number of ACK/NACK bits for the second cell, an ACK/NACK bit position from the first cell can be used to transmit an ACK/NACK bit for the second cell. In some implementations, one or more DTX bits can be used to set the number of ACK/NACK bits in the first cell equal to the number of ACK/NACK bits in the second cell.

First claim

What is claimed is:

1. A method for transmitting Acknowledgement/Negative Acknowledgement (ACK/NACK) bits for carrier aggregation between a first cell and a second cell by a User Equipment (UE), the method comprising:
for a sub-frame, comparing a first number of ACK/NACK bits for the first cell with a second number of ACK/NACK bits for the second cell; and
if the first number of ACK/NACK bits for the first cell is less than the second number of ACK/NACK bits for the second cell,
adding an extra number of ACK/NACK bit positions to the first number of ACK/NACK bits, wherein the extra number is smaller than a difference between the first number and the second number;
transmitting, an ACK/NACK bit for the second cell using one of the extra number of ACK/NACK bit positions from the first cell, wherein the ACK/NACK bit for the second cell that is transmitted in the one of the extra number of ACK/NACK bit positions for the first cell comprises a DTX bit; and
reordering the ACK/NACK bit positions of at least one of an ACK/NACK bit position for the first cell or an ACK/NACK bit position of the second cell, wherein the reordering comprises transmitting a last ACK/NACK bit for the second cell using the bit position of one of a last ACK/NACK bit or a next to last ACK/NACK bit for the first cell, the last ACK/NACK bit for the first cell corresponds to a sub-frame on the first cell that is transmitted last to the UE, and the next to last ACK/NACK bit for the first cell corresponds to a sub-frame that is transmitted immediately prior to the sub-frame on the first cell that is transmitted last to the UE.

2. The method of claim 1 , further comprising:
determining that sub-frames that correspond to the ACK/NACK bits for the first cell are of a different configuration than sub-frames that correspond to the ACK/NACK bits for the second cell.

3. The method of claim 1 , wherein one of ACK/NACK bit positions for the first or the second cell is described in a table, the table associating combinations of ACK/NACK bits to ACK/NACK signals transmitted by the UE.

4. The method of claim 1 , further comprising:
for the sub-frame, determining that the first number of ACK/NACK bits for the first cell is zero; and
indicating with an ACK/NACK Resource Indicator (ARI) a number of resources, the number of resources being equal to the second number of ACK/NACK bits for the second cell.

5. The method of claim 1 , wherein the first cell is a primary cell and the second cell is a secondary cell.

6. The method of claim 1 , wherein the second cell is a primary cell and the first cell is a secondary cell.

7. A user equipment (UE) for transmitting Acknowledgement/Negative Acknowledgement (ACK/NACK) bits to a first cell and a second cell, comprising:
one or more processors configured to:
for a sub-frame, compare a first number of ACK/NACK bits for the first cell with a second number of ACK/NACK bits for the second cell; and
if the first number of ACK/NACK bits for the first cell is less than the second number of ACK/NACK bits for the second cell,
add an extra number of ACK/NACK bit positions to the first number of ACK/NACK bits, wherein the extra number is smaller than a difference between the first number and the second number;
transmit an ACK/NACK bit for the second cell using one of the extra number of ACK/NACK bit positions from the first cell, wherein the ACK/NACK bit for the second cell that is transmitted in the one of the extra number of ACK/NACK bit positions for the first cell comprises a DTX bit; and
reorder the ACK/NACK bit positions of at least one of: an ACK/NACK bit position for the first cell or an ACK/NACK bit position of the second cell; wherein the reordering comprises transmitting a last ACK/NACK bit for the second cell using the bit position of one of: a last ACK/NACK bit or a next to last ACK/NACK bit for the first cell wherein the last ACK/NACK bit for the first cell corresponds to a sub-frame on the first cell that is transmitted last to the UE, and the next to last ACK/NACK bit for the first cell corresponds to a sub-frame that is transmitted immediately prior to the sub-frame on the first cell that is transmitted last to the UE.

Assignees

• Research In Motion Ltd
• Blackberry Ltd

Inventors

• Wang Yiping
• Harrison Robert Mark
• Li Jun

Classifications

• H04W72/20

  Control channels or signalling for resource management · CPC title

• H04L5/001

  the frequencies being arranged in component carriers · CPC title

• H04W28/12 Primary

  using signalling between network elements · CPC title

• H04L1/1614 Primary

  using bitmaps · CPC title

• H04W72/0446

  Resources in time domain, e.g. slots or frames · CPC title