Patent Application
20100329200
The present invention generally relates to allocating uplink resources, and more particularly, to allocating uplink resources in a carrier-aggregated system.
The modern communications era has brought about a tremendous expansion of wireless networks. Various types of networking technologies have been developed resulting in unprecedented expansion of wireless computer networks, television networks, telephony networks, and the like, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer. However, in order to continue to meet the increasing demands of consumers for fast and reliable wireless communications, wireless networking technologies must continue to evolve. Examples of emerging technologies include the evolved universal mobile telecommunications system (UMTS) terrestrial radio access networks including UTRAN, E-UTRAN (also known as Long term Evolution—LTE), LTE advanced (LTE-A), the GERAN (GSM/EDGE) system, as well as advancements related to Worldwide Interoperability for Microwave Access (WiMAX), Wireless Municipal Access Network (WirelessMAN) or the like.
Consider a typical wireless communication system in which user equipment (UE) (or mobile stations, mobile terminals, etc.) communicate with network infrastructure including base stations (BS) (or node B or eNB elements, etc.). A UE may transmit an uplink (UL) control signal via an UL band to respond to a downlink (DL) transmission from a BS via a DL band. As currently defined by LTE-A, for example, these UL and DL bands may be up to 20 MHz. To support a higher data rate in advanced communication systems, however, a wider transmission bandwidth is required. In practice, it is difficult to derive a contiguous band having the desired bandwidth (e.g., 100 MHz) for many situations. In an effort to address this issue, a so-called carrier aggregation technique has been proposed in which multiple bands—each of which may be referred to as a component carrier (CC), may be contiguously or discontiguously aggregated to meet a particular increased system requirement for DL/UL bandwidth. Thus, for example, five 20 MHz component carriers may be aggregated to achieve an effective DL/UL bandwidth of 100 MHz.
In many instances, DL transmissions have a higher data rate than UL transmissions, which in those instances, may imply that the DL has a wider bandwidth and may benefit from aggregation of more CCs than the UL. In the UL in which fewer CCs may be aggregated, then, the UE may be reconfigured to turn off unnecessary or undesired UL CCs when the UE has no need to upload data. Thus, when a communication system implements unequal numbers of DL/UL CCs, a UE may simultaneously transmit multiple UL control signals (or report channel state information) via a single UL CC to respond to DL transmissions via multiple DL CCs.
In light of the foregoing background, exemplary embodiments of the present invention provide improved apparatuses, methods and computer-readable storage mediums for allocating uplink resources (“exemplary” as used herein referring to “serving as an example, instance or illustration”). According to one aspect of exemplary embodiments of the present invention, an apparatus is provided for allocating uplink resources in a system in which a plurality of downlink component carrier bands are aggregated and a plurality of uplink component carrier bands are aggregated, and in which the apparatus is configured to transmit an uplink control signal in one of the uplink component carrier bands in response to a downlink transmission in one of the downlink component carrier bands. The apparatus includes a processor configured to perform or cause the apparatus to perform a number of functions. As recited, the functions include receiving an assignment or an indication of an assignment of a resource index to the apparatus, and deriving one or more additional resource indices for the apparatus as a function of the assigned resource index. Each of the assigned resource index and additional resource indices specify an allocation of uplink resources for the apparatus to transmit uplink control signals. Also, the assigned resource index and additional resource indices may be static, or one or more of the assigned resource index or one or more of the additional resource indices may vary over time in accordance with a hopping function.
The functions according to this aspect also include mapping the assigned and additional resource indices to a subset of uplink component carrier bands, where the subset includes one or more of the plurality of uplink component carrier bands. For each uplink component carrier band in the subset, mapping the assigned and additional resource indices to the uplink component carrier band enables the apparatus to transmit one or more uplink control signals in the uplink component carrier band in accordance with the allocation of uplink resources specified by the respective assigned and additional resource indices.
The resource indices may be mapped in a number of different manners. For example, the assigned and additional resource indices may be sequentially mapped to the uplink component carrier bands of the subset, and employing a module operation to map any remaining resource indices when the number of assigned and additional resource indices exceeds the number of uplink component carrier bands in the subset. As another example, the assigned and additional resource indices may be mapped to the uplink component carrier bands of the subset according to a setting of a number of uplink control signals the apparatus is permitted to transmit in an uplink control carrier band of the subset. In this example, the setting may be such that a different number of resource indices are mapped to at least one component carrier band than are mapped to at least one other component carrier band of the subset.
According to another aspect of exemplary embodiments of the present invention, an apparatus is provided for allocating uplink resources in a system similar to that described above. Additionally, the apparatus similarly includes a processor configured to perform or cause the apparatus to perform a number of functions. As per this other aspect of exemplary embodiments of the present invention, however, the functions include receiving an assignment or an indication of an assignment of a plurality of resource indices to the apparatus, which may be static or one or more of which may vary over time in accordance with a hopping function.
The assigned resource indices are pre-assigned to respective pairs of component carrier bands each of which includes a downlink component carrier band and an uplink component carrier band. The functions of this aspect also include identifying a resource index from the assigned resource indices, where the respective resource index is identified as being pre-assigned to a particular pair of component carrier bands including a downlink component carrier band in which a downlink transmission is received. Additionally, the functions include preparing for transmission an uplink control signal in accordance with the allocation of uplink resources specified by the identified resource index, and prepared for transmission in the uplink component carrier of the particular pair of component carrier bands.
The assigned resource indices may be from a greater plurality of available resource indices pre-assigned to respective pairs of component carrier bands, which may be reflected in a table stored by the user equipment. In such instances, the resource index may be identified from the table, and preparing an uplink control signal may include identifying from the table the uplink component carrier of the particular pair of component carrier bands.
The plurality of downlink component carrier bands and uplink component carrier bands may be organized in groups each of which includes one or more downlink component carrier bands and one or more uplink component carrier bands. Each of the available resource indices may be pre-assigned to each of one or more of the groups. For each group, the respective pre-assigned available resource indices may be further pre-assigned to respective pairs of the component carrier bands of the group. The processor, then, may be further configured to perform or cause the apparatus to receive an assignment or an indication of an assignment of one of the groups to the apparatus; and the resource index may be identified further from the assigned group.
The pre-assigned resource indices may be further pre-assigned to respective pairs of the component carrier bands in a number of different manners. In a localized manner, for example, the pre-assigned resource indices may be further assigned such that ranges of consecutive ones of the respective pre-assigned resource indices are assigned to respective pairs of the component carrier bands. And in a distributed manner, for example, the pre-assigned resource indices may be further assigned such that the respective pre-assigned resource indices are sequentially assigned to respective pairs of the component carrier bands.
In either of the aforementioned aspects of exemplary embodiments of the present invention, the processor may be further configured to perform or cause the apparatus to prepare for transmission a single uplink control signal in one of the uplink component carrier bands in response to downlink transmissions in two or more of the downlink component carrier bands. In these instances, the single uplink control signal may separately reflect an acknowledgement (ACK) or negative acknowledgement (NACK), or a discontinuous transmission (DTX), for each of the downlink transmissions.
As indicated above and explained below, exemplary embodiments of the present invention may solve problems identified by prior techniques and provide additional advantages.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
a, 6b and 6c are tables by which resource indices may be pre-assigned to different pairs of downlink (DL) and UL component carriers, in accordance with a second exemplary embodiment of the present invention;
a and 7b are schematic block diagrams illustrating assigning resource indices to UEs for the transmission of arranged and non-arranged control signals, in accordance with the second exemplary embodiment of the present invention;
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
As shown, the network(s) may include one or more infrastructure components such as base stations (BSs) 102. The BS may be configured to communicate with one or more equipment (UE) 106 (or mobile stations, mobile terminals, etc.) to transmit and receive voice and data information via the network(s)—three example UEs being shown as UE 106a, 106b and 106c. Although a specific numbers of BSs and UEs are shown,
The BS 102 may include any appropriate apparatus or system that facilitates communication between a UE and a network. For example, in some embodiments, the BS may include a wireless communication device installed at a fixed location to create a cell 104 or defined geographic region of network coverage, such as a node B or eNB, a base transceiver system (BTS), an access point, a home BS, etc. In other example embodiments, the BS may be a relay station, an intermediate node, or an intermediary. The BS may include any appropriate type of wireless or radio BS, such as a land-based communication BS or a satellite-based communication BS. The BS may include any appropriate type voice, data, and/or integrated voice and data communication equipment to provide high speed data and/or voice communications. In other example embodiments, any other type of BS or equivalent thereof may be used.
The UEs 106 may be any type of device for communicating with a BS 102. For example, a UE may be a mobile communication device, or any other appropriate computing platform or device capable of exchanging data and/or voice information with BS such as servers, clients, desktop computers, laptop computers, network computers, workstations, personal digital assistants (PDA), tablet PCs, scanners, telephony devices, pagers, cameras, musical devices, etc. A UE may be a fixed computing device operating in a mobile environment, such as, for example, a bus, a train, an airplane, a boat, a car, etc. In some embodiments, a UE may be configured to communicate with the BS using any of the various communication standards supporting mobile communication devices. The UEs may be configured to communicate with other UEs (not shown) directly or indirectly via BS or other BSs or computing systems (not shown) using wired or wireless communication methods.
The processor 202 may include a general purpose processor, application specific integrated circuit (ASIC), embedded processor, field programmable gate array (FPGA), microcontroller, or other like device. The Processor may be configured to act upon instructions and data to process data output from transceiver 214, I/O devices 208, interfaces 210 or other components that are coupled to processor. In some exemplary embodiments, the processor may be configured to exchange data or commands with the memory 204. For example, the processor may be configured to receive computer readable instructions from the memory and perform one or more functions under direction of the respective instructions.
The memory 204 may include a volatile or non-volatile computer-readable storage medium configured to store data as well as software, such as in the form of computer readable instructions. More particularly, for example, the memory may include volatile or non-volatile semiconductor memory devices, magnetic storage, optical storage or the like. The memory may be distributed. That is, portions of the memory may be removable or non-removable. In this regard, other examples of suitable memory include Compact Flash cards (CF cards), Secure Digital cards (SD cards), Multi-Media cards (MMC cards) or Memory Stick cards (MS cards) or the like. In some exemplary embodiments, the memory may be implemented in a network (not shown) configured to communicate with the apparatus 200.
The database 206 may include a structured collection of tables, lists or other data structures. For example, the database may be a database management system (DBMS), a relational database management system, an object-oriented database management system or similar database system. As such, the structure may be organized as a relational database or an object-oriented database. In other exemplary embodiments, the database may be a hardware system including physical computer-readable storage media and input and/or output devices configured to receive and provide access to tables, lists, or other data structures. Further, hardware system database may include one or more processors and/or displays.
The I/O devices 208 include any one or more of a mouse, stylus, keyboard, audio input/output device, imaging device, printing device, display device, sensor, wireless transceiver or other similar device. The I/O devices may also include devices that provide data and instructions to the memory 204 and/or processor 202.
The interfaces 210 may include external interface ports, such as USB, Ethernet, FireWire®, and wireless communication protocols. The interfaces may also include a graphical user interface, or other humanly perceivable interfaces configured to present data, including but not limited to, a portable media device, traditional mobile phone, smart phone, navigation device, or other computing device. The apparatus 200 may be operatively connected to a network (not shown) via a wired and/or wireless communications link using the interface.
The transceiver 214 may include any appropriate type of transmitter and receiver to transmit and receive voice and/or data from other apparatuses (e.g., BS 102, UE 106). In some exemplary embodiments, the transceiver may include one or a combination of desired functional component(s) and processor(s) to encode/decode, modulate/demodulate and/or perform other wireless communication-channel-related functions. The transceiver may be configured to communicate with an antenna 212 (e.g., single antenna or antenna array) to transmit and receive voice and/or data in one of various transmission modes.
As explained in the background section, a UE may transmit an uplink (UL) control signal via an UL band to respond to a downlink (DL) transmission from a BS via a DL band. These control signals may include, for example, a channel quality indicator (CQI), an acknowledgement (ACK), negative acknowledgement (NACK) or the like. These ACK/NACK control signals may be configured according to any of a number of different error control techniques, such as the hybrid automatic repeat request (HARQ) technique. To support a higher data rate in advanced communication systems, multiple component carrier (CC) bands may be aggregated to meet a particular increased system requirement for DL/UL bandwidth. Thus, for example, five 20 MHz component carriers may be aggregated to achieve an effective DL/UL bandwidth of 100 MHz. An example of the aggregation of multiple CCs is shown in
As also shown in
In a wireless communication system such as LTE, a BS may allocate UL resources to UEs served by the BS. For each UE, its allocated resources may be reflected by a UE-specific resource index. In this regard, the UE may map to a resource block (RB) location m in an UL subframe on the UL—a physical uplink control channel (PUCCH) in the context of LTE. And as control signals from multiple UEs may be multiplexed within a single RB, the resource index may be mapped to a multiplexing code (cyclic shift of a particular sequence—CS) and an orthogonal cover (OC), if necessary. This is shown, for example, in
Exemplary embodiments of the present invention provide an apparatus, method and computer-readable storage medium for allocating uplink resources to user equipment. According to one exemplary embodiment, to avoid the BS 102 using extra overhead to signal multiple resource indices for a UE 106, each UE may be assigned a single resource index without regard to a number of UL control signals the UE may simultaneously transmit. Each UE, then, may derive other resource indices from its respectively assigned resource index. After a UE is assigned or otherwise derives its resource indices, the UE may accordingly arrange its UL control signals over UL CCs according to a predefined rule, and calculate corresponding RB locations and determine corresponding code (CS and/or OC) selections based upon the respective resource indices.
According to a second exemplary embodiment, each UL control signal from each UE 106 may be assigned a resource index. That is, a UE may be assigned multiple resource indices at one time. For each UE, the resource indices may be assumed to be pre-assigned to different pairs of DL and UL CCs. Also for each UE, the BS 102 and UE may both maintain the same knowledge on how the resource indices have been assigned to CCs, such as by using the same table or tables. In this regard, an assigned resource index may inform a UE which UL CC should be selected to transmit a control signal when a DL transmission is received from a particular DL CC. The system may therefore experience increased flexibility to arrange or schedule the UL control signals of the UEs. This increased flexibility may permit the system to realize benefits such as balanced UL CC loading and balanced physical uplink control information (PUCCH) performance, randomized multiple access interference on PUCCH, power saving and the like.
According to a third exemplary embodiment, DL and UL CCs may be organized in groups, which may be UE-specific or cell-specific. Generally, each UL control signal may be sent in an UL CC of a DL/UL group responsive to the DL transmission from a DL CC of the same group. To realize power savings, the UL control information may be transmitted at the same time such as by employing a bundling- or multiplexing-based method.
According to the aforementioned three exemplary embodiments, the UEs 106 may be assigned one or more resource indices nPUCCH in any of a number of different manners. As described herein, these and other assignments may be made by the BS 102 serving the UE. It should be understood, however, one or more assignments described herein may be alternatively made by another network infrastructure component implementing the same or higher-layer functionality than the BS, such as a radio network controller (RNC) implementing radio resource control (RRC) functionality. Regardless of the particular assigning-component, the respective component may transmit an indication of the assignment to the respective UE, as appropriate.
Relative to resource indices, for example, the assigning-component may communicate an indication of the assigned resource index/indices to the UE 106 (e.g., BS 102 to UE, or RNC—via BS—to UE). More particularly, for example, the assigning-component may communicate actual assigned resource index/indices to the UE. Alternatively, for example, the assigning-component may communicate resource index-related information to the UE. In these instances, the UE may calculate the actual assigned resource index/indices based on the resource index-related information, alone or further based on additional similar information—such as information received by the UE on a DL control channel. As one example, see 3GPP TS 36.213, which describes calculation of an actual assigned resource index as the combination of a control channel element index (nCCE) and higher-layer-configured resource index-related information (NPUCCH).
Each of the aforementioned three exemplary embodiments will now be described in greater detail. It should be understood that the BS 102 and any UE 106 may be configured to operate according to any one or more of the exemplary embodiments. Thus, for example, the BS and all of its served UEs may operate according to one of the exemplary embodiments. Alternatively, for example, the BS may be configured to operate according to multiple ones of the exemplary embodiments, with various ones of the served UEs being configured to operate according to different ones of the exemplary embodiments (e.g., some UEs being configured to operate according to the first exemplary embodiment, while others of the UEs are configured to operate according to the second exemplary embodiment).
More particularly with reference to the first exemplary embodiment, each UE 106 may be assigned a single resource index, regardless of how many UL control signals the UE may transmit at any given time or period of time. Each UE, then, may derive other resource indices from its respectively assigned resource index, such as in accordance with a predefined function and a cell-specific or UE-specific parameter. In various instances, this parameter may be predetermined or otherwise set by the BS or higher-layer functionality (e.g., RNC implementing RRC functionality), which may transmit an indication of the parameter to the UE.
Also in accordance with the first exemplary embodiment, consider that the BS 102 (or higher-layer functionality) may assign a subset of UL CCs to each UE 106 for the transmission of UL control signals, and the BS may transmit an indication of the respective subset to the UE. Additionally, the BS (or higher-layer functionality) may set the number of UL control signals that may be transmitted in an UL CC of the subset, an indication of which may be transmitted by the BS along with an indication of the subset to each UE.
After a UE 102 receives an indication of the assigned resource index and derives other resource indices, and receives an indication of a subset of UL CCs, the UE may map its resource indices over the subset of UL CCs according to a predefined mapping rule such that each UE may include one or more resource indices mapped to each of one or more UL CCs. For each resource index in each UL CC, then, the UE may calculate the corresponding RB location and determine the corresponding code (CS and/or OC) selection based on the resource index, and transmit a control signal in the UL CC according to the respective RB location and code selection. This may be accomplished, for example, in accordance with the LTE specification as reflected in 3GPP TS 36.211.
Different UEs 102 may be assigned the same resource index and may include some of the same UL CCs in their respective subsets, and a UE may map one or more resource indices to any UL CC. The resource indices may be assigned and derived, the subset of UL CCs may be assigned, and/or the predefined mapping rule may be configured such that the resource index or indices of each UE within a particular UL CC is/are unique to the respective UE—thereby avoiding collisions between the indices of different UEs within the same UL CC. According to one example, the predefined mapping rule may specify that each UL sequentially map its resource indices to UL CCs in its subset beginning with the largest/smallest resource index and corresponding largest/smallest index of UL CC. And in instances in which the number of resource indices is greater than the number of UL CCs in the subset, the UE may employ a module operation to map the remaining resource indices after a resource index has been mapped to each UL CC in the subset.
A method for deriving resource indices and mapping the resource indices over subsets of UL CCs according to exemplary embodiments of the present invention may be more notationally represented for a UE-k and five available UL CCs in accordance with LTE as follows:
To further illustrate this first exemplary embodiment, consider an example scenario in which a BS 102 assigns resource indices nPUCCH=25, 26, 21, 22, 23, 22 to respective ones of a number of UEs 106 designated UE-1, K, 2, 3, 4, 5; and may set UE-specific parameters Δk for the respective UEs (the subscript k reflecting a particular UE-k) as follows: {1, 1, 2, 2, 1, 1}. The UEs may therefore derive other resource indices from their respectively assigned resource indices, such as follows:
Also per the above example scenario, the BS 102 may assign subsets of UL CCs {0, 1, 2}, {0, 1, 2, 4}, {0, 1, 2, 4}, {0, 1, 2, 4, 5}, {0, 2, 4, 5}, {4, 5} to respective ones of UE-1, K, 2, 3, 4, 5.
Each UE 106 may map its resource indices over its subset of UL CCs, such as by sequentially assigning the resource indices to UL CCs, and applying a module operation when the number of resource indices is greater than the number of UL CCs. For example, UE-1 may sequentially and respectively assign resource indices {25, 26, 27} to UL CCs {0, 1, 2}, and then assign the remaining resource indices {28, 29} to UL CCs {0, 1} according to the module operation. The resource indices mapped to UL CCs according to the above example scenario are illustrated in
In the example shown in
According to a second exemplary embodiment, resource indices available for assignment to UEs 106 may be pre-assigned to different pairs of DL CCs and UL CCs, which may be reflected in a table known to the BS 102 and UEs. Also according to this second exemplary embodiment, each UE may be assigned to multiple resource indices at one time. Similar to before, the BS may transmit an indication of the assigned resource indices to the respective UEs. In one more particular example, each UE 106 may be assigned to a number of resource indices equal to the number of DL CCs by which the UE may receive a DL transmission that triggers a control signal. Each of the DL CCs may be paired with an UL CC on which the UE may transmit a control signal. And these DL and UL CCs may be paired such that any two or more DL CCs may be paired with the same UL CC (the number of DL CCs in these instances being greater than the number of UL CCs), thereby permitting assignment of each UE to a respective UE-specific UL CC or a respective UE-specific set of UL CCs. In this regard, a number of the resource indices may be used to transmit non-arranged UL control signals, and others of the resource indices may be used to transmit arranged UL control signals. For a pair of corresponding DL and UL CCs (e.g., DL-0 and UL-0), a non-arranged UL control signal may be one transmitted on an UL CC (e.g., UL CC-0) responsive to a DL transmission on the corresponding DL CC (e.g., DL CC-0), and an arranged UL control signal maybe one responsive to a DL transmission on another DL CC (e.g., DL CC-1).
A UE 106, with knowledge of its assigned resource indices and respective assigned pairs of DL and UL CCs, may be configured to identify a resource index for a control signal responsive to a DL transmission on a particular DL CC. The UE may then calculate the corresponding RB location and determine the corresponding code (CS and/or OC) selection based on the resource index, and transmit a control signal in the UL CC paired with the respective DL CC according to the respective RB location and code selection. In this manner, complex calculations may be avoided, and the BS may save overhead by avoiding the need to signal the UE as to the resource index and UL CC by which to transmit a control signal.
An example of a table by which resource indices may be pre-assigned to different pairs of DL and UL CCs is shown in
The pre-assignment of blocks of resource indices to pairs of DL and UL CCs may be known to the BS 102 and UEs 106 served by the BS in a cell 104. As shown in
To further illustrate this second exemplary embodiment, and following the example tables of
Now presume that for UE-1, the BS 102 desires to arrange the control signals such that those responsive to DL transmissions in DL CC-2 are transmitted in UL CC-0 (DL CC-2 to UL CC-0), and such that those responsive to DL transmissions on DL CC-4 are transmitted in UL CC-3 (DL CC-4 to UL CC-3). To accomplish this arrangement, the BS may assign nPUCCH=50, 70, 80, 106, 176 to UE-1, as shown in
As shown in
As the example of
As shown in
In each group of DL/UL CCs, each pair of DL CC and UL CC may have multiple resource indices assigned to it. The assignment of resource indices in a group may be localized or distributed. That is, as shown in
Each UE 106 may be assigned to one or more groups of DL/UL CCs and, similar to the second exemplary embodiment, may be assigned to multiple resource indices. An indication of the assigned group and resource indices may be transmitted to the respective UEs. A UE, with knowledge of its assigned resource indices and groups of DL/UL CCs, may be configured to identify a resource index for a control signal responsive to a DL transmission on a particular DL CC. The UE may then calculate the corresponding RB location and determine the corresponding code (CS and/or OC) selection based on the resource index, and transmit a control signal in the UL CC paired with the respective DL CC according to the respective RB location and code selection.
Reference is now made to
For an UL transmission opportunity,
As also shown in
Similarly, when UE-2 transmits an UL control signal in UL CC-2 utilizing resource index nPUCCH, DL CC-2(2)=2, the UL control signal may belong to paired DL CC-2. When UE-2 transmits an UL control signal in UL CC-2 utilizing nPUCCH, DL CC-3(2)=1077, the UL control signal may belong to paired DL CC-3. And when UE-2 transmits an UL control signal in UL CC-2 utilizing resource index nPUCCH, DL CC-4(2)=1555, the UL control signal may belong to DL CC-4.
The various exemplary embodiments described above may apply to any number of different UL control signals, such as CQI with or without ACK, NACK control signals. In other instances, the above exemplary embodiments may more particularly include transmission of ACK/NACK control signals in accordance with various techniques permitting transmission of multiple such signals. Examples of these techniques, referred to as “ACK/NACK multiplexing” and “ACK/NACK bundling” are described in greater detail below.
According to one example ACK/NACK multiplexing technique, a UE 106 may be configured to transmit multiple ACKs (e.g., HARQ-ACKs) in a single UL CC. As shown in
When UE-2 receives a DL transmission on DL CC-2, CC-3 and CC-4, UE-2 may transmit a corresponding ACK/NACK control signal in UL CC-2 in the corresponding UL transmission time. Table 2 below illustrates a detail signal presentation technique whereby the control signal may include three bits ACK/NACK in the UL. For example, when {A/NDL CC-2, A/NDL CC-3, A/NDL CC-4}={ACK, NACK, ACK}, UE-2 may transmit [b(0), b(1)]=[1, 1] in UL CC-2 and use the corresponding resource nPUCCH, DL CC-2(2)=1000 to generate the control signal.
Similar to the ACK/NACK multiplexing technique, according to one example ACK/NACK bundling technique, a UE 106 may be configured to transmit multiple ACKs (e.g., HARQ-ACKs) on single UL CC. According to the bundling technique, however, multiple ACK/ACK control signals may be bundled by Boolean ‘AND’ operators to generate one or two bit bundled ACK/NACK.
As shown in
When the DL transmission includes one codeword for each DL CC, the UE may generate a one bit ACK/NACK for DL CC-0 and CC-1, b(0)=[(A/NDL CC-0) AND (A/NDL CC-1)]. In this regard, A/NDL CC-0 may refer to an ACK/NACK responsive to the DL transmission on DL CC-0; and A/NDL CC-1 may refer to an ACK/NACK responsive to the DL transmission on DL CC-1. In this example, there may be two resource indices {nPUCCH, DL CC-0(1),nPUCCH, DL CC-1(1)}={999, 2026} that may be used for transmitting the ACK on the UL. UE-1 may select one of the resource indices based on a pre-defined rule, and transmit the bundled ACK. For example, UE-1 may select nPUCCH, DL CC-0(1)=999.
When the DL transmission includes two or more codewords for each DL CC, UE-1 may generate a two bit ACK/NACK for DL CC-0 and CC-1, and may perform ACK/NACK bundling per codeword across two DL CCs. For example, A/NDL CC-0(0) may refer to an ACK/NACK responsive to the first codeword on DL CC-0; A/NDL CC-0(1) may refer to an ACK/NACK responsive to the second codeword on DL CC-0; A/NDL CC-1(0) may refer to an ACK/NACK responsive to the first codeword on DL CC-1; and A/NDL CC-1(1) may refer to an ACK/NACK responsive to the second codeword on DL CC-1. Hence, two bit ACK/NACK bundling information [b(0), b(1)] may be obtained by,
Similar to UE-1, when UE-2 receives a DL transmission on DL CC-2, CC-3 and CC-4, UE-2 may transmit a corresponding ACK/NACK control signal in UL CC-2 in corresponding UL transmission time. When the DL transmission includes a single codeword for each DL CC, UE-2 may generate a one bit ACK/NACK for DL CC-2, CC-3 and CC-4, b(0)=[(A/NDL CC-2) AND (A/NDL CC-3) AND (A/NDL CC-4)]. In this regard, A/NDL CC-2 may refer to an ACK/NACK responsive to the DL transmission on DL CC-2; A/NDL CC-3 may refer to an ACK/NACK responsive to the DL transmission on DL CC-3; and A/NDL CC-4 may refer to an ACK/NACK responsive to the DL transmission on DL CC-4. In this example, there may be three resource indices {nPUCCH, DL CC-2(1),nPUCCH, DL CC-3(1),nPUCCH, DL CC-4(1)}={1000, 1097, 2044} may be used for transmitting the ACK. UE-2 may select a resource index based on a pre-defined rule, and may transmit the bundled ACK according to it. For example, UE-2 may select nPUCCH, DL CC-2(1)1000.
When the DL transmission includes two or more codewords for each DL CC, UE-2 may generate a two bit ACK/NACK for DL CC-2, CC-3 and CC-4, and ACK/NACK bundling may be performed per codeword across three DL CCs. For example, A/NDL CC-2(0) may refer to an ACK/NACK for the first codeword transmitted on DL CC-2; A/NDL CC-2(1) may refer to an ACK/NACK for the second codeword on DL CC-2; A/NDL CC-3(0) may refer to an ACK/NACK for the first codeword on DL CC-3; A/NDL CC-3(1) may refer to an ACK/NACK for the second codeword on DL CC-3; A/NDL CC-4(0) may refer to an ACK/NACK for the first codeword on DL CC-4; and A/NDL CC-2(1) may refer to an ACK/NACK for the second codeword on DL CC-4. Hence, two bit ACK/NACK bundling information [b(0), b(1)] may be obtained by,
According to exemplary embodiments of the present invention, a UE 106 may be assigned or may otherwise derive a number of resource indices for use in transmitting UL control signals, and in various instances may be further assigned to a group of DL/UL CCs. These resource indices and/or group of DL/UL CCs may be static over time or, in various instances, may vary over time such as in accordance with a hopping function—which in addition to an initially-assigned or derived resource index and/or DL/UL CC group and time, may also include as a variable the range of resource indices and/or DL/UL CC groups available to a particular UE. This time hopping of resource indices and/or DL/UL CC groups may permit randomization in the UL control channel (PUCCH).
According to one aspect of the present invention, all or a portion of the BS 102 and/or UE 106 of exemplary embodiments of the present invention, generally operate under control of a computer program. The computer program for performing the methods of exemplary embodiments of the present invention may include one or more computer-readable program code portions, such as a series of computer instructions, embodied or otherwise stored in a computer-readable storage medium, such as the non-volatile storage medium.
Accordingly, blocks or steps of the block diagrams support combinations of means for performing the specified functions, combinations of steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that one or more blocks or steps of the block diagrams, and combinations of blocks or steps in the block diagrams, may be implemented by special purpose hardware-based computer systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.
Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. It should therefore be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
The present application claims priority to U.S. Provisional Patent Application No. 61/219,989, entitled: Resource Assignment for Uplink Control Channel, filed on Jun. 24, 2009, the content of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61219989 | Jun 2009 | US |
