HK1189725A - Harq/ack codebook size determination - Google Patents

Description

HARQ/ACK codebook size determination

Cross Reference to Related Applications

Priority of the present application for U.S. provisional patent application No. 61/612188 entitled WIRELESS communication system and method, filed on 3, 16, 2012, the entire disclosure of which is incorporated herein by reference.

Technical Field

Embodiments of the invention relate generally to the field of communications and, more particularly, to determining a size of a hybrid automatic repeat request-acknowledgement (HARQ-ACK) codebook (codebook) in a wireless communication network.

Disclosure of Invention

Release 8 of the third generation partnership project (3GPP) Long Term Evolution (LTE) standard describes piggybacking Uplink Control Information (UCI) on a Physical Uplink Shared Channel (PUSCH). Channel quality indicator/precoding matrix indicator (CQI/PMI) resources are placed at the beginning of uplink shared channel (UL-SCH) data resources and mapped sequentially to all single carrier frequency division multiple access (SC-FDMA) symbols on one subcarrier before continuing on the next subcarrier. The UL-SCH data is rate-matched to the CQI/PMI data. The HARQ-ACK resources are mapped to SC-FDMA symbols by puncturing (puncturing) PUSCH data Resource Elements (REs). Therefore, reducing PUSCH REs punctured by HARQ-ACK symbols will improve PUSCH performance.

In accordance with the above, Release 8 provides a method for transmitting Downlink Control Information (DCI) in the format 0/4,A 2-bit Downlink Allocation Index (DAI) for indicating a total number of Downlink (DL) allocations in the bundling window. Assuming a bundling window size of M, if PUSCH transmission is adjusted based on a detected PDCCH with a DCI format of 0/4, onlyThe individual HARQ-ACK bits, rather than the M bits, need to be fed back to the transmitting device, e.g., an advanced node base station (eNB). Thus, reducing DL subframes corresponding to not scheduled by eNBAnd a useless HARQ-ACK bit.

Release 10 of the LTE standard (Rel-10) introduces carrier aggregation, where more than one Component Carrier (CC) may be used for data transmission. In a release 10 Time Division Duplex (TDD) system, with piggybacking on PUSCH, the HARQ-ACK codebook size is determined by the number of CCs, their configured transmission modes, and the number of downlink subframes in the bundling window. For TDD UL-DL configurations 1-6, and when configuring PUCCH format 3 for transmission of HARQ-ACK, the HARQ-ACK codebook size is determined by the following equation:

(1)。

where C is the number of configured CCs,is the number of CCs configured with a multiple-input multiple-output (MIMO) transmission mode enabling reception of two transport blocks;is the number of downlink subframes for which the UE needs to feed back HARQ-ACK bits for the c-th serving cell. For TDD UL-DL configurations 1, 2, 3, 4 and 6, the UE will assume PUSCH subframe n onComprises the following steps:

(2)。

wherein, according to the following table,determined by the DAI in DCI format 0/4:

TABLE 1

[0008] The DAI may be communicated in subframes having a predetermined correlation with the subframe n of each serving cell. For example, the DAI may be in a subframeMiddle transfer, defined in the table below：

TABLE 2

[0009] Since the TDD UL-DL configuration of each serving cell is always the same in Rel-10, andmust not be greater than the bundling window size, soThe determined HARQ-ACK codebook size is always equal to the minimum number of HARQ-ACK bits and is the best compromise between HARQ-ACK overhead and performance.

In release 11 of the 3GPP LTE standard, inter-band CA for TDD with CCs (with different UL-DL configurations for each serving cell) is supported. Having different UL-DL configurations in different serving cells may result in different HARQ-ACK bundling windows. Therefore, the UL grant (grant) -based HARQ-ACK codebook size determination in the previous release cannot effectively reduce the HARQ-ACK overhead.

Drawings

The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Fig. 1 schematically illustrates a wireless communication network in accordance with various embodiments;

fig. 2 illustrates an example TDD communication structure with HARQ-ACK timing information, in accordance with various embodiments;

fig. 3 is a flow diagram illustrating a method of determining a HARQ-ACK codebook size, which may be performed by a user equipment, in accordance with various embodiments;

fig. 4 is a HARQ-ACK bit generation table according to some embodiments;

fig. 5 schematically depicts an example system in accordance with various embodiments.

Detailed Description

Example embodiments of the present disclosure include, but are not limited to, methods, systems, computer-readable media and devices for determining a size of a HARQ-ACK codebook in a wireless communication network. Various embodiments may provide a user equipment operating in accordance with release 11 (hereinafter "Rel-11") (and later releases) of 3GPP LTE that is capable of determining a HARQ-ACK codebook size on PUSCH in a manner that reduces HARQ-ACK overhead while maintaining HARQ-ACK performance for inter-band CA for TDD CCs with different UL-DL configurations for different serving cells. In this manner, the described UE may adaptively determine a desired HARQ-ACK codebook size to puncture PUSCH REs, which will reduce adverse impact on PUSCH with little or no additional overhead.

Various embodiments may be described with reference to specific configurations (e.g., TDD UL-DL configurations and special subframe configurations), formats (e.g., DCI formats), modes (e.g., transmission modes), and so on. These configurations, formats, modes, etc., may be defined in accordance with recently published LTE literature (e.g., Rel-10 and/or Rel-11 specifications).

Various aspects of the illustrative embodiments will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. It will be apparent to those skilled in the art that alternative embodiments may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the illustrative embodiments. It will be apparent, however, to one skilled in the art that alternative embodiments may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative embodiments.

In addition, various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the example embodiments; however, the order of description should not be construed as to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.

The phrase "in some embodiments" is used repeatedly. The phrase generally does not refer to the same embodiment; however, it may indicate the same embodiment. The terms "comprising," "having," "including," and "containing" are synonymous, unless the context dictates otherwise. The phrase "A and/or B" means (A), (B) or (A and B). The phrase "A/B" means (A), (B), or (A and B), similar to the phrase "A and/or B". The phrase "at least one of A, B and C" means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). The phrase "(a) B" means (B) or (a and B), that is, a is optional.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the embodiments of the present disclosure. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments of the present disclosure be limited only by the claims and the equivalents thereof.

As used herein, the term module may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group), a combinational logic circuit, or other electronic circuits that provide the described functionality. In various embodiments, a module may execute instructions stored in one or more computer-readable media to provide the described functionality.

Fig. 1 schematically illustrates a wireless communication network 100 in accordance with various embodiments. The wireless communication network 100 (hereinafter "network 100") may be an access network of a 3GPP LTE network, such as an evolved universal terrestrial radio access network (E-UTRAN). Network 100 may include a base station, such as an advanced node base station (eNB)104, configured to wirelessly communicate with User Equipment (UE) 108.

As shown in fig. 1, the UE 108 may include a feedback controller 112 coupled with a transceiver module 116. The transceiver module 116 may further be coupled with one or more of the plurality of antennas 132 of the UE 108 for wireless communication with other components of the network 100 (e.g., the eNB 104).

In some embodiments, the UE 108 may be capable of utilizing Carrier Aggregation (CA), in which some Component Carriers (CCs) are aggregated for communication between the eNB 104 and the UE 108. The transceiver module 116 may be configured to communicate with the eNB 104 through a plurality of serving cells employing a respective plurality of CCs. The CCs may be disposed in different bands and may be associated with different TDD UL-DL configurations (hereinafter also referred to as "UL-DL configurations"). Thus, in some embodiments, at least two serving cells may have different UL-DL configurations.

Table 3 below shows an example UL-DL configuration that may be used in various embodiments of the present invention.

TABLE 3

In table 3, D is a subframe of downlink transmission, U is a subframe of uplink transmission, and S is a special subframe used, for example, in guard time. In some embodiments, a special subframe may include three fields: a downlink pilot time slot (DwPTS), a Guard Period (GP), and an uplink pilot time slot (UpPTS) of the DCI may be included.

At initial connection setup, the UE 108 may employ a level one CC (also may be referred to as CC)₀) Connected with a primary serving cell (PCell) of the eNB 104. This connection may be used for various functions such as security, mobility, configuration, etc. Subsequently, the UE 108 may connect with one or more secondary serving cells (scells) of the eNB 104 using one or more secondary CCs. These connections may be used to provide additional radio resources.

Fig. 2 illustrates an example TDD communication structure 200 with HARQ-ACK timing information, according to an embodiment. In the TDD communication structure 200, three serving cells may be configured for communication between the eNB 104 and the UE 108. For example, PCell with UL-DL configuration 0, SCell 1 with UL-DL configuration 2, and SCell2 with UL-DL configuration 1. In other embodiments, other numbers of serving cells may be configured for communication between the eNB 104 and the UE 108.

In the TDD communication structure 200, the PCell may have a bundling window (bundling window) M including one subframe₀The subframe may include a downlink transmission (e.g., indicating downlink semi-persistent scheduling (SPS)) A PDSCH transmission or PDCCH transmission of a release) for which corresponding HARQ-ACK information is transmitted as a PUSCH transmission in an associated uplink subframe (e.g., subframe 7 of SCell 1). SCell 1 may have a bundling window M including four subframes₁The four subframes may include a downlink transmission for which corresponding HARQ-ACK information is transmitted as a PUSCH transmission in an associated uplink subframe (e.g., subframe 7 of SCell 1). SCell2 may have bundling window M including two subframes₂The two subframes may include a downlink transmission for which corresponding HARQ-ACK information is transmitted as a PUSCH transmission in an associated uplink subframe (e.g., subframe 7 of SCell 1). The correlation between DL subframes and UL subframes of a respective bundling window to be used for transmitting corresponding HARQ-ACK information may be based on a predetermined HARQ timing reference. Examples of such HARQ timing references are shown and discussed below with respect to table 4.

In the example shown in fig. 2, it is shown that all subframes capable of carrying a downlink transmission (for which the corresponding HARQ-ACK information is transmitted) have PDSCH transmissions. However, in other embodiments, the eNB may not schedule downlink transmissions on one or more of these subframes.

Fig. 3 illustrates a method 300 of determining a HARQ-ACK codebook size, in accordance with some embodiments. The method 300 may be performed by a feedback controller of a UE, such as the feedback controller 112 of the UE 108. In some embodiments, the UE may include and/or have access to one or more computer-readable media having instructions stored thereon that, when executed, cause the UE or feedback controller to perform method 300.

At 304, the feedback controller may determine HARQ-ACK timing and bundling window for each configured serving cell. In some embodiments, the feedback controller may determine, for each configured serving cell, a total number of subframes within a bundling window associated with uplink subframes. In general, the HARQ-ACK bundling window may include both downlink subframes and special subframes, as they are both capable of carrying PDSCH transmissions. However, in some embodiments, certain special subframes may be excluded from the bundling window in order to reduce the HARQ-ACK codebook size. For example, special subframes with configuration 0 and configuration 5 of a standard downlink Cyclic Prefix (CP) or configuration 0 and configuration 4 of an extended downlink CP may be excluded from the bundling window because they typically do not carry PDSCH transmissions. The special subframe configuration may be defined in accordance with table 4.2-1 of 3GPP Technical Specification (TS)36.211 V10.5.0 (2012-06).

In some embodiments, the predetermined downlink correlation set index may be in accordance with TDDTo determine HARQ-ACK timing and bundling window M_cAs shown in the UL-DL configuration of the HARQ timing reference of table 4.

TABLE 4

In various embodiments, each serving cell may have the same or different HARQ timing reference as the UL-DL configuration of the serving cell. The UL-DL configuration of the serving cell is conveyed in System Information Block (SIB)1 of the serving cell and, therefore, may also be referred to as SIB1 configuration of the serving cell. The HARQ timing reference of the PCell may be the same as the SIB1 configuration of the PCell, and the HARQ timing reference of the SCell may be selected according to table 5 by considering both the SIB1 configuration of the SCell and the SIB1 configuration of the PCell.

TABLE 5

According to table 5, and referring to fig. 2, PCell will use UL-DL configuration 0 for its HARQ timing reference, SCell 1 will use UL-DL configuration 2 for its HARQ timing reference, and SCell2 will use UL-DL configuration 1 for its HARQ timing reference. Although this embodiment shows both scells using their SIB1 configuration for HARQ timing reference, in other embodiments, scells may use other UL-DL configurations for their HARQ timing references. For example, if SCell 1 has SIB1 configuration of 3 and PCell has SIB1 configuration of 1, then SCell will use UL-DL configuration 4 for its HARQ timing reference.

To further illustrate the utility of tables 4 and 5, consider the following. Since subframe 7 (e.g., n =7) of SCell 1 is specified as the uplink subframe for transmitting HARQ-ACK information, the associated downlink subframe may be determined by n-K, where K ∈ K. Size M of binding window_cIs the base of the element set K, while the specific subframe of the bundling window is composed ofAnd (4) determining. Therefore, the size M of the bundling window of the PCell₀Is 1 (in table 4, subframe n =7, considering that only one element is associated with UL-DL configuration 0), and M₀Is 7-6=1, e.g., DL subframe 1. Size M of bundling window of SCell 1₁Is 4 (consider the four elements of Table 4), and M₁The DL subframes of (1) are subframes 3(7-4), subframes 1(7-6), subframes 0(7-7), and subframe 9 of the previous frame (7-8). Size M of bundling window of SCell2₂Is 2 (consider the two elements of Table 4), and M₂The DL subframes of (1) are subframes 0(7-7) and subframes 1 (7-6).

At 308, the feedback controller may determine the DAI. The DAI may be communicated in a subframe having a predetermined correlation with an uplink subframe n, e.g., which would carry the HARQ-ACK information for the bundling window in subframe 7 of SCell 1. In some embodiments, the DAI may be in a subframeWherein, is defined in table 2. In some casesIn the examples, DAI can be used to determine。A maximum value of a number of scheduled downlink subframes within a bundling window that may correspond to multiple serving cells. With reference to figure 2 of the drawings,=4 because 4 downlink subframes are scheduled in SCell 1.

At 312, the feedback controller may determine a number of HARQ-ACK bits on a PUSCH of an uplink subframe corresponding to the configured serving cell. In some embodiments, the feedback controller may be based onTo determine the number of HARQ-ACK bits for each serving cell,based on the DAI of the uplink resource allocation, and the feedback controller may determine the number of subframes of the bundling window of the corresponding serving cell according to the HARQ timing reference configuration.

In some embodiments, the number of HARQ-ACK bits for the c-th serving cell, O, may be determined using the following equation_c。

Equation 1.

Wherein U is among all configured serving cellsThe maximum value of (a) is,is the total number of subframes (e.g., subframe(s) n-K described with respect to table 4, where K ∈ K) having transmissions received in the bundling window of the c-th serving cell (e.g., PDSCH and PDCCH indicating downlink SPS release),determined by a DAI included in DCI, which may have a format of 0 or 4, allocating uplink transmission resources of a serving cell, wherein UCI is in a subframe according to Table 1Piggybacked on PUSCH (e.g., SCell 1), whereDefined in table 2; if the transmission mode configured in the c-th serving cell supports one transport block, it is determined whether the transport block is supported by the c-th serving cell=1, otherwise= 2; and if X ≦ Y, Min (X, Y) = X, otherwise Min (X, Y) = Y.

In embodiments where none of the plurality of aggregated serving cells includes configuration 5 as the HARQ timing reference configuration,will be at least as large as U, eliminating equation 1An item. Thus, equation 1 reduces to:

equation 2.

Thus, in some embodiments, if none of the aggregate serving cell's HARQ timing reference configurations is configuration 5, equation 2 will be used in UL subframe n, and associated therewith, havingAnd if the HARQ timing reference of any of the aggregated serving cells is configured as configuration 5, equation 1 will be used for having HARQ-ACK transmission in UL subframe n, and associated therewith, in the PUSCH adjusted by the UL grantIs used for HARQ-ACK transmission on the adjusted PUSCH.

It may be noted that in some embodiments, neither equation 1 nor equation 2 may be used in the case where the serving cell (e.g., SCell 1 in fig. 2) performing PUSCH scheduling has SIB1 configuration 0. In these embodiments, the eNB may not be able to transmit the DAI in DCI format 0/4, and thus the UE will not be able to determine W.

HARQ-ACK feedback bits for the c-th serving cellIs constructed as follows, wherein c is ≧ 0: HARQ-ACK for PDSCH transmission is associated with a DCI message for PDDCH or PDCCH transmission indicating the downlink SPS release and transmission in subframe n-kIn association with, if the transmission mode configured in the c-th serving cell supports one transport block, or withIs associated with otherwiseIn association with each other, the information is stored,where DAI (k) is the value of DAI, which is used for resource allocation of the downlink subframe, in DCI format 1A/1B/1D/1/2/2A/2B/2C detected in subframe n-k, depending on the bundling window in the C-th serving cell. The HARQ-ACK feedback bit without any detected PDSCH transmission or without detected PDCCH indicating downlink SPS release may be set to NACK.

An example is provided below, with reference to fig. 2, and it is assumed that transmission mode 4 with two active transport blocks is configured. The special subframe of each CC is configured to have a configuration 3 of a standard downlink Cyclic Prefix (CP). As stated above, in this example, the eNB may transmit at various occasions within the specified bundling window, e.g., subframe 1 of PCell, subframes 9, 0, 1, and 3 of SCell 1, and subframes 0 and 1 of SCell 2. In addition, the UE may receive an uplink grant for a PUSCH transmission in subframe 3 of SCell 1 at subframe 7 of SCell 1. Since the maximum of the total number of PDSCH scheduling subframes within the bundling window is 4 according to the current assumption, uplink grant of subframe 7Should be set to 4 by the eNB. O of HARQ-ACK bit of PCell according to equation 1₀The value can be calculated as follows

。

In the same manner, the HARQ-ACK bits of SCell 1 and SCell2 may be determined to be O, respectively₁=8 and O₂And = 4. This is graphically illustrated in the HARQ-ACK bit generation table 400 of fig. 4, according to some embodiments. If the HARQ-ACK bit is determined according to the Rel-10 method, the result will be O₀=8、O₁=8 and O₂=8。

At 316, the feedback controller may determine a HARQ-ACK codebook size on the PUSCH of the uplink subframe. The HARQ-ACK codebook size may be determined by summing the number of HARQ-ACK bits corresponding to each of the plurality of serving cells according to the following equation,

equation 2.

In the example discussed above, O = 14. In the Rel-10 method, O = 24. Thus, the described embodiments reduce the HARQ-ACK overhead by 42%. In this manner, PUSCH performance and system throughput may be improved without affecting HARQ-ACK performance.

The UE 108 described herein may be implemented into a system by being configured as desired using any suitable hardware and/or software. For one embodiment, fig. 5 illustrates an example system 500 comprising one or more processors 504, system control logic 508 coupled with at least one of the processor(s) 504, system memory 512 coupled with the system control logic 508, non-volatile memory (NVM)/storage 516 coupled with the system control logic 508, a network interface 520 coupled with the system control logic 508, and an input/output (I/O) device 532 coupled with the system control logic 508.

Processor(s) 504 may include one or more single-core or multi-core processors. The processor(s) 504 may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, baseband processors, etc.).

System control logic 508 for one embodiment may include any suitable interface controllers to provide for any suitable interface to at least one of processor(s) 504, and/or to any suitable device or means for communicating with system control logic 508.

System control logic 508 for one embodiment may include one or more memory controllers to provide an interface to system memory 512. System memory 512 may be used to load and store data and/or instructions for system 500. In some embodiments, system memory 512 may include HARQ logic 524, which when executed, HARQ logic 524 causes the feedback controller to perform various operations described herein. System memory 512 for one embodiment may comprise any suitable volatile memory, such as suitable Dynamic Random Access Memory (DRAM), for example.

NVM/storage 516 may include one or more tangible, non-transitory computer-readable media to store data and/or instructions (e.g., HARQ logic 524). NVM/storage 516 may include any suitable non-volatile memory, such as, for example, flash memory, and/or may include any suitable non-volatile memory device(s), such as, for example, one or more Hard Disk Drives (HDDs), one or more Compact Disk (CD) drives, and/or one or more Digital Versatile Disk (DVD) drives.

NVM/storage 516 may include a storage resource that is physically part of a device on which system 500 is installed, or NVM/storage 516 may be accessible by, but not necessarily part of, the device. For example, the NVM/storage 516 may be accessed over a network via the network interface 520 and/or the NVM/storage 516 may be accessed via input/output (I/O) devices 532.

Network interface 520 may have a transceiver module 522 similar to transceiver module 116 to provide a radio interface for system 500 to communicate over one or more networks, and/or to communicate with any other suitable device. In various embodiments, the transceiver module 522 may be integrated with other components of the system 500. For example, transceiver module 522 may include a processor of processor(s) 504, memory of system memory 512, and NVM/storage of NVM/storage 516. Network interface 520 may include any suitable hardware and/or firmware. The network interface 520 may include multiple antennas to provide a multiple-input multiple-output radio interface. Network interface 520 for one embodiment may include, for example, a wired network adapter, a wireless network adapter, a telephone modem, and/or a wireless modem.

For one embodiment, at least one of the processor(s) 504 may be packaged together with logic for one or more controller(s) of system control logic 508. For one embodiment, at least one of the processor(s) 504 may be packaged together with logic for one or more controller(s) of system control logic 508 to form a packaged System (SiP). For one embodiment, at least one of the processor(s) 504 may be integrated on the same die with logic for one or more controller(s) of system control logic 508. For one embodiment, at least one of the processor(s) 504 may be integrated on the same die with logic for one or more controller(s) of system control logic 508 to form a system on chip (SoC).

In various embodiments, the I/O devices 532 may include a user interface designed to enable user interaction with the system 500, a peripheral component interface designed to enable peripheral component interaction with the system 500, and/or sensors designed to determine environmental conditions and/or location information related to the system 500.

In various embodiments, the user interface may include, but is not limited to, a display (e.g., a liquid crystal display, a touch screen display, etc.), speakers, headphones, one or more video cameras (e.g., a camera and/or camcorder), a flash (e.g., a light emitting diode flash), and a keyboard.

In various embodiments, the peripheral component interface may include, but is not limited to, a non-volatile memory port, a Universal Serial Bus (USB) interface, a headset jack, and a power interface.

In various embodiments, the sensors may include, but are not limited to, a gyroscopic sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of the network interface 520 or interact with the network interface 520 to communicate with components of a positioning network, such as Global Positioning System (GPS) satellites.

In various embodiments, system 500 may be an eNB or a mobile computing device, such as (but not limited to) a laptop computing device, a tablet computing device, a notebook, a smartphone, or the like. In various embodiments, system 500 may have more or fewer components, and/or different architectures.

Although certain embodiments have been illustrated and described herein for purposes of description, it is contemplated that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that the embodiments described herein be limited only by the claims and the equivalents thereof.

Claims (26)

1. An apparatus, comprising:

a transceiver module configured to communicate over a plurality of serving cells, wherein at least two of the serving cells have different Time Division Duplex (TDD) uplink-downlink (UL-DL) configurations; and

a feedback controller coupled with the transceiver module and configured to:

receiving, by the transceiver module, a Downlink Assignment Index (DAI);

determining a number of downlink subframes within a bundling window of a first serving cell of the plurality of serving cells, wherein the downlink subframes of the bundling window are associated with uplink subframes for transmitting corresponding hybrid automatic repeat request-acknowledgement (HARQ-ACK) information; and

determining a number of HARQ-ACK bits available on a Physical Uplink Shared Channel (PUSCH) of the uplink subframe corresponding to the first serving cell based on the DAI and the determined number of downlink subframes.

2. The apparatus of claim 1, wherein the DAI corresponds to a maximum of a number of scheduled downlink subframes within a bundling window of the plurality of serving cells, wherein the downlink subframes within the bundling window of the plurality of serving cells are associated with the uplink subframes, and the feedback controller is further configured to:

determining the HARQ-ACK bit based on the maximum value.

3. The apparatus of claim 1, wherein the DAI is included in Downlink Control Information (DCI) that allocates uplink transmission resources of a serving cell having the uplink subframe.

4. The apparatus of claim 3, wherein the DCI has a format that is DCI Format 0 or DCI Format 4.

5. The device of claim 1, wherein at least one of the subframes within the bundling window comprises a Physical Downlink Shared Channel (PDSCH) transmission associated with a Downlink Control Information (DCI) message of a Physical Downlink Control Channel (PDCCH) or a downlink semi-persistent scheduling (SPS) transmission indicating downlink semi-persistent scheduling (SPS) issued to a User Equipment (UE) to which the HARQ-ACK information corresponds.

6. The apparatus of claim 1, wherein

The number of downlink subframes within the bundling window associated with the uplink subframe does not include configuration 0 and configuration 5 with a standard downlink Cyclic Prefix (CP) or special subframes with configuration 0 and configuration 4 with an extended downlink CP.

7. The apparatus of claim 1, wherein the feedback controller is further configured to:

determining a number of HARQ-ACK bits available on the PUSCH of the uplink subframe corresponding to each of the plurality of serving cells; and

determining a HARQ-ACK codebook size on the PUSCH for the uplink subframe based on the determined number of HARQ-ACK bits corresponding to each of the plurality of serving cells.

8. The device of claim 7, wherein the feedback controller is configured to determine the HARQ-ACK codebook size by being configured to aggregate the determined number of HARQ-ACK bits corresponding to each of the plurality of serving cells.

9. The apparatus of claim 1, wherein the feedback controller is further configured to:

determining a value corresponding to the DAI;

selecting either the determined value or the determined number of downlink subframes that are less than the number of HARQ-ACK bits of the first serving cell; and

determining a HARQ-ACK codebook size on the PUSCH of the uplink subframe based on a number of HARQ-ACK bits of the first serving cell.

10. The apparatus of claim 9, wherein the feedback controller is further configured to:

determining a number of transport blocks supported per subframe for a transmission mode of the first serving cell; and

determining a number of HARQ-ACK bits for the first serving cell based on the determined number of transport blocks supported per subframe.

11. The apparatus of claim 9, wherein the feedback controller is further configured to:

determining a number of HARQ-ACK bits corresponding to each of the plurality of serving cells; and

determining the HARQ-ACK codebook size based on the determined number of HARQ-ACK bits corresponding to each of the plurality of serving cells.

12. The apparatus of claim 11, wherein the feedback controller is further configured to

Determining a number of HARQ-ACK bits corresponding to each of the plurality of serving cells based on the following equation:

，

wherein c is an index of the first serving cell, O_cIs the number of HARQ-ACK bits corresponding to the c-th serving cell,a number of downlink subframes of a bundling window of the c-th serving cell, wherein the bundling window is determined according to a HARQ timing reference of the c-th serving cell and excludes configuration 0 and configuration 5 with a standard downlink Cyclic Prefix (CP) and special subframes with configuration 0 and configuration 4 with an extended downlink CP,is uplink resource division corresponding to the plurality of serving cellsA determined value of the DAI in a configured DCI format, andis the number of transport blocks supported per subframe for the transmission mode of the c-th serving cell.

13. The apparatus of claim 9, wherein the feedback controller is further configured to:

determining a number of downlink semi-persistent scheduling (SPS) version PDSCH and PDCCH transmissions indicating being received in subframes of a bundling window of each of the plurality of serving cells;

determining a maximum value of the determined numbers indicating downlink SPS version of PDSCH transmissions and PDCCH transmissions received in subframes of bundling windows for each of the plurality of serving cells; and

determining a number of HARQ-ACK bits based on the determined maximum value.

14. The apparatus of claim 13, wherein the feedback controller is further configured to determine the number of HARQ-ACK bits corresponding to each serving cell based on the following equation:

where c is the serving cell index, O_cIs the number of HARQ-ACK bits corresponding to the c-th serving cell,is a number of downlink subframes in a bundling window of the c-th serving cell, wherein the bundling window is determined according to a HARQ timing reference configuration of the c-th serving cell and excludes configurations 0 and 5 with a standard downlink Cyclic Prefix (CP) and configurations with an extended downlink CPA special subframe of set 0 and configuration 4,is a value corresponding to the DAI, U is the determined maximum value, andis the number of transport blocks supported per subframe for the transmission mode of the c-th serving cell.

15. The device of claim 14, wherein the feedback controller is further configured to determine a HARQ-ACK codebook size O based on the following equation:

wherein the content of the first and second substances,is the plurality of serving cells.

16. The apparatus of claim 13, wherein the feedback controller is further configured to:

determining a number of HARQ-ACK bits corresponding to each serving cell based on the following equation in case that the HARQ timing reference configuration of at least one of the plurality of serving cells is UL-DL configuration 5:

determining a number of HARQ-ACK bits corresponding to each of the plurality of serving cells based on the following equation in the absence of the HARQ timing reference configuration of the plurality of aggregated serving cells being UL-DL configuration 5:

where c is the serving cell index, O_cIs the number of HARQ-ACK bits corresponding to the c-th serving cell,is the number of downlink subframes in the bundling window of the c-th serving cell,is the value of the DAI in the DCI format corresponding to the uplink resource allocation, U is the determined maximum value, andis the number of transport blocks supported per subframe for the transmission mode of the c-th serving cell.

17. The device of claim 1, wherein the uplink subframe is in a second serving cell of the plurality of serving cells.

18. The apparatus of claim 1, wherein a number of HARQ-ACK bits corresponds to the downlink subframe of the bundling window for the first serving cell.

19. The device of claim 18, wherein the correlation of the downlink subframes and the uplink subframes of the bundling window is based on a predetermined HARQ-ACK timing reference.

20. One or more computer-readable media having instructions stored thereon that, when executed, cause a User Equipment (UE) to:

configuring a plurality of serving cells for communication, wherein at least two of the serving cells have different Time Division Duplex (TDD) uplink-downlink (UL-DL) configurations;

determining a size of a bundling window for individual serving cells of the plurality of serving cells;

determining a value corresponding to a maximum number of scheduled downlink subframes within the bundling window for the plurality of serving cells; and

determining a size of a HARQ-ACK codebook on a first uplink subframe associated with the bundling window of the plurality of serving cells based on the size of the bundling window and the determined value.

21. The one or more computer-readable media of claim 20, wherein the instructions, when executed, further cause the UE to:

receiving a downlink allocation index; and

determining the value based on the downlink allocation index.

22. The one or more computer-readable media of claim 21, wherein the instructions, when executed, further cause the UE to:

determining a number of HARQ bits of a bundling window for the individual serving cell based on the following equation with a HARQ timing reference of at least one of the plurality of serving cells configured as configuration 5:

determining the number of HARQ bits for the bundling window for the individual serving cell based on the following equation without the HARQ timing reference configuration for the plurality of serving cells being configuration 5:

wherein c is an index of the first serving cell, O_cIs the number of HARQ bits corresponding to the c-th serving cell,is a number of downlink subframes in a bundling window of the c-th serving cell, wherein the bundling window is determined according to a HARQ timing reference configuration of the c-th serving cell and excludes configuration 0 and configuration 5 with a standard downlink Cyclic Prefix (CP) and special subframes with configuration 0 and configuration 4 with an extended downlink CP,is the determined value of the plurality of serving cells,is a number of Physical Downlink Shared Channel (PDSCH) transmissions and Physical Downlink Control Channel (PDCCH) transmissions indicating a downlink semi-persistent scheduling (SPS) version received in a subframe of a bundling window of a c-th serving cell, U isIs a maximum value ofIs the number of transport blocks supported per subframe for the transmission mode of the c-th serving cell.

23. The one or more computer-readable media of claim 20, wherein the instructions, when executed, further cause the UE to:

puncturing a Physical Uplink Shared Channel (PUSCH) resource element of the first uplink subframe based on the determined size of the HARQ-ACK codebook.

24. One or more computer-readable media having instructions that, when executed, cause a feedback controller to:

receiving a Downlink Assignment Index (DAI); and

in a case where the HARQ timing reference of at least one serving cell of the plurality of configured serving cells is configured to be configuration 5, the number of HARQ-ACK bits corresponding to each serving cell is determined based on the following equation:

determining a number of HARQ-ACK bits corresponding to each of the plurality of serving cells based on the following equation with the HARQ timing references of the plurality of aggregated serving cells configured as configuration 5:

wherein c is an index of the first serving cell, O_cIs the number of HARQ bits corresponding to the c-th serving cell,is a number of downlink subframes in a bundling window of a c-th serving cell, wherein the bundling window is determined according to a HARQ timing reference configuration of the c-th serving cell and excludes configuration 0 and configuration 5 with a standard downlink Cyclic Prefix (CP) and special subframes with configuration 0 and configuration 4 with an extended downlink CP,is a value of the DAI in a DCI format corresponding to an uplink resource allocation,is a Physical Downlink Shared Channel (PDSCH) transmission and a Physical Downlink Control Channel (PDCCH) transmission indicating a downlink semi-persistent scheduling (SPS) version received in a subframe of a bundling window of a c-th serving cell, and U isIs a maximum value ofIs the number of transport blocks supported per subframe for the transmission mode of the c-th serving cell.

25. The one or more computer-readable media of claim 24, wherein the instructions, when executed, further cause the feedback controller to:

determining a system information block 1(SIB 1) configuration for a primary serving cell (PCell) of the plurality of serving cells;

determining a SIB1 configuration for a second secondary serving cell (SCell) of the plurality of configured serving cells; and

determining a HARQ timing reference for the SCell based on the SIB1 configuration of the PCell and the SIB1 configuration of the SCell.

26. The one or more computer-readable media of claim 25, wherein the instructions, when executed, further cause the feedback controller to:

determining a number of downlink subframes in a bundling window for the SCell based on the determined HARQ timing reference.