HK1165920A - Multiple carrier acknowledgment signaling - Google Patents

Description

Multi-carrier acknowledgement signaling

Technical Field

The present invention relates generally to the field of communications, and more particularly, by way of example and not limitation, to acknowledgement signaling in a multi-carrier environment.

Background

Many specific terms and acronyms are used in the field of communications technology. In the following text, at least some of the following terms and acronyms are referred to, as in the background and/or in the following description. Thus, the following terms and abbreviations are defined herein:

3GPP third generation partnership project

ACK acknowledgement

ARQ automatic repeat request

CQI channel quality indicator

DC-HSDPA dual carrier/dual cell HSDPA

DTX discontinuous transmission

HARQ hybrid automatic repeat request

HSDPA high speed downlink packet access

HS-DPCCH high speed special physical control channel (in WCDMA)

HS-DSCH high speed downlink shared channel

HSPA high speed packet access

HS-SCCH high-speed shared control channel

MC-HSDPA Multi-Carrier/Multi-cell HSDPA

MIMO multiple input multiple output

NACK negative acknowledgement

POST ack/nack rear synchronization (POSTamble)

PRE ack/nack PREamble (PREamble)

WCDMA wideband code division multiple access

Electronic communication forms the backbone of today's information-oriented society. Electronic communications are transmitted through wireless or wired channels using electromagnetic radiation, such as Radio Frequency (RF) transmissions, light waves, and the like. The accessibility and capacity of electronic communications are often limited by the bandwidth of the communication channel between a first (e.g., transmitting) device and a second (e.g., receiving) device.

The available bandwidth of the communication channel may be increased by employing any of a number of different schemes. One such example scheme is to communicate over multiple carriers. The multi-carrier operation may include multi-cell operation. High Speed Packet Access (HSPA), including High Speed Downlink Packet Access (HSDPA), is currently evolving to include multi-carrier and/or multi-cell operation. The initial step is to support dual carrier and/or Dual Cell (DC) HSDPA operation (DC-HSDPA). With DC-HSDPA, a user can receive from two carriers "simultaneously". This increases high data rate coverage.

With some communication systems, such as those implemented according to Wideband Code Division Multiple Access (WCDMA), communication between a sender and a receiver is performed by automatic repeat request (ARQ) or hybrid ARQ (harq) operations. Therefore, to support DC-HSDPA, positive Acknowledgements (ACK) or Negative Acknowledgements (NACK) are used to support HARQ operations on each of the two carriers. Several proposals have been proposed to support HARQ operation on each of the two carriers.

The first proposal requires the use of a separate high speed dedicated physical control channel (HS-DPCCH) to signal two ACK/NACK indications (one per carrier). However, it has been noted that such schemes have a severe coverage impact when transmitting two HS-DPCCHs. Furthermore, the cubic metric (cubic metric) is slightly larger when the second HS-DPCCH is transmitted alone than when the first HS-DPCCH is transmitted alone. This results in worse coverage when the mobile terminal needs a separate ACK/NACK second carrier than it needs a separate ACK/NACK first carrier.

The second proposal typically requires signaling two ACK/NACK indications using joint coding and one HS-DPCCH. In this scheme, two ACK/NACK messages are jointly encoded and transmitted using one HS-DPCCH. There are eight (8) jointly coded messages indicating a dual ACK/NACK condition:

● ACK (Carrier 1) & ACK (Carrier 2)

● ACK (Carrier 1) & NACK (Carrier 2)

● ACK (Carrier 1) & DTX (Carrier 2)

● NACK (Carrier 1) & ACK (Carrier 2)

● NACK (Carrier 1) & NACK (Carrier 2)

● DTX (Carrier 1) & DTX (Carrier 2)

● DTX (Carrier 1) & ACK (Carrier 2)

● DTX (Carrier 1) & NACK (Carrier 2)

In the case of "DTX (carrier 1) and DTX (carrier 2)", the mobile terminal need not transmit any ACK/NACK signaling.

One particular proposal for joint coding is to reuse the existing eight (8) MIMO ACK/NACK/PRE/POST codewords specified in 3GPP TS 25.212 table 15B. An example codebook according to this particular proposal is given below:

ACK/DTX＝ [1 1 1 1 1 1 1 1 1 1]

NACK/DTX＝ [0 0 0 0 0 0 0 0 0 0]

DTX/ACK＝ [1 0 1 0 1 1 1 1 0 1]

DTX/NACK＝ [1 1 0 1 0 1 0 1 1 1]

ACK/ACK＝ [0 1 1 1 1 0 1 0 1 1]

ACK/NACK＝ [1 0 0 1 0 0 1 0 0 0]

NACK/ACK＝ [0 0 1 0 0 1 0 0 1 0]

NACK/NACK＝[0 1 0 0 1 0 0 1 0 0]。

however, there are drawbacks in the existing proposals for supporting DC-HSDPA. As mentioned above, the previous proposal with two separate ACK/NACK indications creates a severe coverage impact when transmitting two HS-DPCCHs. The latter approach creates a different set of defects described herein below.

Accordingly, there is a need to address deficiencies in the state of the art with respect to supporting multi-carrier and/or multi-cell communications (e.g., DC-HSDPA). One or more of the various embodiments of the present invention address such deficiencies and other needs.

Disclosure of Invention

It is an object of the present invention to overcome or at least ameliorate one or more of the disadvantages identified further above and below herein. It is an object of certain embodiments of the present invention to achieve an enhanced minimum hamming distance for a codebook having codewords that jointly encode ACK/NACK signaling for multiple carriers. It is another object of some embodiments of the invention to support PRE and POST operations through such codebooks.

In an example embodiment, there is a method in a remote terminal for acknowledgment uplink signaling in a multi-carrier mode. First, a codeword for jointly encoding acknowledgement signaling for at least two carriers is determined from a multi-carrier codebook stored in at least one memory of the remote terminal. The multi-carrier codebook includes eight codewords defined as a sub-codebook having a single-carrier codebook as the multi-carrier codebook, each of the eight codewords having a length of 10. The multi-carrier codebook achieves a minimum hamming distance of 4 between eight codewords. Secondly, an uplink signaling message comprising the determined codeword is transmitted from the remote terminal to the radio network node.

In another example embodiment, there is a method in a radio network node for acknowledgment uplink signaling in a multi-carrier mode. First, an uplink signaling message is received at a radio network node from a remote terminal, the signaling message comprising a codeword jointly encoding acknowledgement signaling for at least two carriers. Second, the codeword is decoded using a multi-carrier codebook stored in at least one memory of the wireless network node. The multi-carrier codebook includes eight codewords defined as a sub-codebook having a single-carrier codebook as the multi-carrier codebook, each of the eight codewords having a length of 10. The multi-carrier codebook achieves a minimum hamming distance of 4 between eight codewords.

In yet another example embodiment, there is a remote terminal adapted to perform acknowledgment uplink signaling in a multi-carrier mode. The remote terminal includes at least one memory storing a multi-carrier codebook and one or more processors. The multi-carrier codebook includes eight codewords defined as a sub-codebook having a single-carrier codebook as the multi-carrier codebook, each of the eight codewords having a length of 10. The multi-carrier codebook achieves a minimum hamming distance of 4 between eight codewords. The one or more processors are configured to: a codeword for jointly encoding acknowledgement signaling for at least two carriers is determined from a multi-carrier codebook and an uplink signaling message including the determined codeword is transmitted from a remote terminal to a radio network node.

In yet another example embodiment, there is a wireless network node adapted to perform acknowledgment uplink signaling in a multi-carrier mode. The wireless network node includes at least one memory storing a multi-carrier codebook and one or more processors. The multi-carrier codebook includes eight codewords defined as a sub-codebook having a single-carrier codebook as the multi-carrier codebook, each of the eight codewords having a length of 10. The multi-carrier codebook achieves a minimum hamming distance of 4 between eight codewords. The one or more processors are configured to: an uplink signaling message from a remote terminal is received at a radio network node, the signaling message comprising a codeword for jointly encoding acknowledgement signaling for at least two carriers, and the codeword is decoded using a multi-carrier codebook.

One advantage of certain embodiments of the present invention is that an enhanced minimum hamming distance may be achieved for codebooks having codewords that jointly encode ACK/NACK signaling for multiple carriers. Another advantage of certain embodiments of the present invention is that PRE and POST operations may be supported. Still another advantage of certain embodiments of the present invention is that codebook ambiguity can be avoided when there is a misinterpretation between the remote terminal and the wireless network node as to whether single-carrier mode or multi-carrier mode activity. Yet another advantage of certain embodiments of the present invention is that the maximum possible codeword separation can be achieved for messages with opposite acknowledgement meanings. Other advantages are mentioned herein below.

Other embodiments are also described and/or claimed herein. Example additional embodiments include, by way of example and not limitation, arrangements, memories, devices, systems, and the like. Additional aspects of the invention are set forth, in part, in the detailed description, figures and claims which follow, and in part are derived from the detailed description and figures, or can be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as disclosed or claimed.

Drawings

A more complete understanding of the present invention may be derived by referring to the following detailed description when considered in conjunction with the following figures, wherein:

fig. 1 is a block diagram of an example communication system including a wireless network node and a plurality of remote terminals.

FIG. 2 is an example state diagram for extended ACK/NACK signaling including PRE and POST operations.

Fig. 3 is a block diagram of example apparatuses configured to communicate using a multi-carrier codebook, according to an embodiment of the present invention.

Fig. 4 is a block diagram of an example multi-carrier codebook.

Fig. 5 is a flow diagram of an example general method for multi-carrier acknowledgement signaling.

Fig. 6A is a block diagram illustrating a hamming distance analysis performed on an example multi-carrier codebook.

Fig. 6B is a block diagram illustrating an example codeword pair with opposite meanings.

Fig. 7 is a block diagram of an example apparatus that may be used to implement an embodiment of multicarrier acknowledgement signaling.

Detailed Description

As described above herein, existing schemes that support multi-carrier and/or multi-cell communications (e.g., DC-HSDPA) have drawbacks. The first existing proposal would use two separate ACK/NACK indications. It will cause severe coverage impact when transmitting two HS-DPCCHs. The second existing proposal would reuse the existing eight (8) MIMOACK/NACK/PRE/POST codewords already specified in 3 GPP.

Although reusing the existing eight MIMO codewords can jointly encode two ACK/NACK indications, thereby avoiding the need for separate transmission for dual carrier ACK/NACK signaling, using this proposal brings a different set of drawbacks. For example, such a codebook formed from the existing eight MIMO codewords would have a minimum hamming distance of only 3, which is much lower than the optimal minimum hamming distance for a length 10 and size 8 codebook. Further, since MIMO derived codewords 7 and 8 ("NACK/ACK ═ 0010010010 ]" and "NACK/NACK ═ 0100100100 ]") have the same value as the existing PRE and POST indications, PRE and POST operations cannot be supported.

In contrast, the example code embodiments described herein below have a better minimum hamming distance. Two different example multi-carrier code embodiments are set forth below. The first example multi-carrier code embodiment has a minimum hamming distance of 5 and the second example multi-carrier code embodiment has a minimum hamming distance of 4. Both example multi-carrier code present embodiments can be configured to support PRE and POST operations. The second example multi-carrier code present embodiment may also include a single carrier ACK/NACK signaling codebook that is a sub-codebook or a subset thereof. The second example multi-carrier code present embodiment may also ensure that codeword pairs having codewords with opposite meanings have a larger hamming distance separation between them. In an example implementation, the first and second example multi-carrier code present embodiments may require a codebook that supports ACK/NACK signaling using one HS-DPCCH for DC-HSDPA operation in a WCDMA-based communication system.

In addition to HARQ ACK/NACK signaling, two CQIs may be signaled during DC-HSDPA operation. A similar problem with CQI can arise when the remote terminal does not detect an HS-SCCH order to disable DC-HSDPA operation. This can cause CQI codebook ambiguity between the wireless network node and the remote terminal. Example embodiments that address this issue are described herein below.

Integrating the DC-HSDPA features and the MIMO HSDPA features can be problematic when using a MIMO-type HS-DPCCH format for DC-HSDPA. Example embodiments that enable a combination of DC-HSDPA features and MIMO HSDPA features are also described herein below.

Fig. 1 is a block diagram of an example communication system 100 including a wireless network node 102 and a plurality of remote terminals 104. Thus, as shown, communication system 100 includes at least one wireless network node 102 and one or more remote terminals 104a and 104 b. Although only two remote terminals 104a and 104b are explicitly shown, the wireless network node 102 may communicate with more or less than two such remote terminals 104. Similarly, although only one radio network node 102 is shown in fig. 1, each given mobile terminal 104 may communicate with a plurality of such radio network nodes 102 (e.g., in multi-cell mode). Alternatively, the wireless network node 102 may be a wired network node communicating with the wireless terminal over a wired connection.

Communication from the wireless network node 102 to the remote terminal 104 is commonly referred to as downlink communication. Communication from remote terminal 104 to wireless network node 102 is commonly referred to as uplink communication. In an example embodiment, the downlink communication 106 is transmitted from the wireless network node 102 to the remote terminal 104a. The remote terminal 104a receives the downlink communication 106 and processes it.

In response to receiving and/or processing downlink communications 106, remote terminal 104 formulates an uplink response message 108. As described herein below, the uplink response message 108 may include at least one codeword. The remote terminal 104a transmits an uplink response message 108 to the radio network node 102. The radio network node 102 may process the uplink response message 108 appropriately, e.g. by decoding the included codeword.

In the context of certain example embodiments as described herein, the uplink response message 108 indicates a reception status with respect to one or more downlink communications 106. The reception condition may be indicated by one or more included codewords. The indicated reception condition may be, for example, a positive acknowledgement, a negative acknowledgement, no reception, a preamble operation, a postsynchronization operation, some combination thereof, and so forth. Different reception conditions are described herein below with particular reference to fig. 2.

The wireless network node 102 may include, for example, a base station, a base transceiver station, a radio base station, a node B, an access point, some combination thereof, and so forth. Remote terminal 104 may include, for example, a mobile terminal, a mobile station, user equipment, a subscriber station, a communication card or module, some combination thereof, and so forth. A general example apparatus implementation for a wireless network node 102 and/or a remote terminal 104 is described herein below with particular reference to fig. 7.

Some of the example technologies referenced herein are expressed using WCDMA terminology. However, it should be understood that this is only one example implementation that is suitable for WCDMA based systems. In other words, the remote terminal may be of any general type, and the network node may be part of the infrastructure of any general wireless (or wired) network. In a wireless implementation, the principles of the present invention may be implemented using other air interface technologies (e.g., which conform to different wireless network standards). Such wireless network standards may or may not relate to cellular type wireless networks.

FIG. 2 is an example state diagram 200 for extended ACK/NACK signaling including PRE and POST operations. As shown, the state diagram 200 includes three states: a Discontinuous Transmission (DTX) state 202, a Preamble (PRE) state 204, and an ACK/NACK state 206. PRE and POST operations are introduced to improve ACK/NACK detection performance. As shown in the state diagram 200, a trellis structure (trellis structure) is added to the ACK/NACK signaling channel.

When the remote terminal detects the high speed shared control channel (HS-SCCH) for sub-frame n, it sends a preamble "PRE" indication in the HS-DPCCH in sub-frame n-1 to transition from the DTX state 202 to the PRE state 204. If the remote terminal does not detect a high speed downlink shared channel (HS-DSCH) in subframe n after receiving the HS-DSCH in subframe n-1, it sends a POST-synchronization "POST" indication in subframe n to transition from the ACK/NACK state 206 to the DTX state 202. The use of the preamble and postamble indications enables the radio network node to better distinguish between DTX and bursty ACK/NACK transmissions.

Fig. 3 is a block diagram 300 of an example apparatus 302 configured to communicate using a multi-carrier codebook 312 in accordance with an embodiment of the present invention. As shown, the apparatus 302 includes a transmitter 304, a receiver 306, a communication validation unit 308, a single-carrier codebook 310, and a multi-carrier codebook 312. More specifically, the first apparatus 302a includes a transmitter 304a, a receiver 306a, a communication validation unit 308a, a single-carrier codebook 310a, and a multi-carrier codebook 312 a. The second device 302b includes a receiver 306b, a transmitter 304b, a communication validation unit 308b, a single-carrier codebook 310b, and a multi-carrier codebook 312 b. Each device 302a and 302b may include more or fewer components than shown in the figures.

In an example embodiment, the first apparatus 302a acts as a wireless network node 102 (fig. 1) and the second apparatus 302b acts as a remote terminal 104, such as remote terminal 104a. Thus, the first device 302a uses the transmitter 304a to transmit the downlink communication 106 to the second device 302b, which is received by the receiver 306 b. The second device 302b transmits the uplink response message 108 to the first device 302a using the transmitter 304b, which communication is received by the receiver 306 a. The uplink response message 108 may include at least one ACK indication, at least one NACK indication, or at least one transition operation indication for one or more carriers. If the second device 302b does not detect the presence of the downlink communication 106, it will not transmit the uplink response message 108. Such a case is referred to herein as DTX, for example.

In an example implementation, the indications may be communicated using at least one codeword from one or more codebooks. Devices 302 may use single carrier codebook 310 to determine and decode/interpret codewords when communicating over a single carrier. When devices 302 communicate over multiple carriers, they may use multicarrier codebook 312 to determine and decode/interpret codewords. An example multi-carrier codebook 312 relating to at least two carriers/cells is described below with particular reference to fig. 4. The codeword determination is performed by the communication validation unit 308b of the second device 302b and the codeword decoding is performed by the communication validation unit 308a of the first device 302 a.

Fig. 4 is a block diagram of an example multi-carrier codebook 312. As shown, the multi-carrier codebook 312 includes an example dual-carrier codebook 312-2. For an example embodiment, the dual-carrier codebook 312-2 includes a total of ten codewords 402. It includes eight "acknowledgement" codewords 402 a-h. The dual-carrier codebook 312-2 may also include two "transition operation" codewords 402i and 402 j. However, the dual-carrier codebook 312-2 may alternatively include a different number of codewords and/or a set of codewords having different meanings.

An example reception status implication for the set of codewords 402 of dual-carrier codebook 312-2 is provided below. Codeword 402a indicates an "ACK/DTX" reception condition, which corresponds to a positive acknowledgement (e.g., for a received transport block) on the first carrier and no reception (e.g., no received transport block) on the second carrier. The codeword 402b indicates a "NACK/DTX" reception condition, which corresponds to a negative acknowledgement on the first carrier (e.g., for an incorrectly received transport block) and no reception on the second carrier. Codeword 402c indicates a "DTX/ACK" reception condition, which corresponds to no reception on the first carrier and a positive acknowledgement on the second carrier. The codeword 402d indicates a "DTX/NACK" reception condition, which corresponds to no reception on the first carrier and a negative acknowledgement on the second carrier.

The codeword 402e indicates a "NACK/ACK" reception condition, which corresponds to a negative acknowledgement on the first carrier and a positive acknowledgement on the second carrier. The codeword 402f indicates an "ACK/NACK" reception condition, which corresponds to a positive acknowledgement on the first carrier and a negative acknowledgement on the second carrier. Codeword 402g indicates an "ACK/ACK" reception condition, which corresponds to a positive acknowledgement on the first carrier and a positive acknowledgement on the second carrier. The codeword 402h indicates a "NACK/NACK" reception condition, which corresponds to a negative acknowledgement on the first carrier and a negative acknowledgement on the second carrier.

As described above, the multi-carrier codebook 312, such as the dual-carrier codebook 312-2, may also include codewords for the transition operation. The codeword 402i indicates a reception condition for a "PRE" operation, which corresponds to a preamble transition operation. Codeword 402j indicates the receive status for a "POST" operation, which corresponds to a POST-synchronization transition operation.

The values located on these codewords can form different multicarrier codebooks 312. Different multi-carrier codebooks 312 having different values may result in multi-carrier codebooks 312 having different properties. The first and second example code embodiments are described herein below. Each codeword in these two example codebook embodiments has a length of 10 values (e.g., 10 bits), but the codewords may alternatively be of different lengths.

For the first example code embodiment, a multi-carrier codebook 312 that may be implemented using one HS-DPCCH for DC-HSDPA HARQ acknowledgment signaling is described. The codebook may have the following example values for each of the codewords:

ACK/ACK＝ [1 1 1 1 1 1 0 1 1 0]

NACK/DTX＝ [1 1 1 0 1 1 1 0 0 1]

DTX/ACK＝ [1 1 0 1 0 0 1 0 1 0]

DTX/NACK＝ [0 0 0 1 1 1 1 1 1 1]

ACK/ACK＝ [1 0 0 0 0 1 1 1 0 0]

ACK/NACK＝ [0 1 0 1 0 1 0 0 0 1]

NACK/ACK＝ [1 0 0 0 1 0 0 0 1 1]

NACK/NACK＝[0 1 1 0 0 0 1 1 1 1]。

this codebook has a minimum hamming distance equal to 5.

With this first example code embodiment, the same two more codewords as legacy PRE/POST can be added to also support PRE/POST functionality. The minimum hamming distance can remain equal to 5 even if legacy PRE/POST codewords are added. This first example code embodiment enables considerably better message error rate performance than codebooks based on existing 8 MIMO ACK/NACK/PRE/POST codewords.

However, using the first example code for dual carrier ACK/NACK signaling this embodiment implies that the remote terminal will fall back to release 5 (single carrier) ACK/NACK signaling upon receiving the HS-SCCH order to deactivate DC-HSDPA operation. As a result, problems can arise when a remote terminal misses such an HS-SCCH order and therefore remains using the DC-HSDPA HARQ acknowledgement codebook while the wireless network node begins to decode the received codeword using the (single carrier) release 5 codebook.

Release 5 single carrier codebook contains the following two codewords for ACK single carrier indication and NACK single carrier indication:

ACK＝ [1 1 1 1 1 1 1 1 1 1]

NACK＝[0 0 0 0 0 0 0 0 0 0]。

as shown in state diagram 200 (fig. 2), acknowledgement signaling may be preceded by PRE and POST transition operation indicators. As an example, the PRE and POST codewords may have the following two (legacy) values:

PRE＝ [0 0 1 0 0 1 0 0 1 0]

POST＝[0 1 0 0 1 0 0 1 0 0]。

to address possible ambiguity when the remote terminal fails to detect the HS-SCCH order (e.g., the codebook may not match between the remote terminal and the radio network node), the codebook used for MC-HSDPA HARQ acknowledgment signaling may comprise a single carrier codebook as the sub-codebook or a subset thereof. The second example code embodiment described below includes a single carrier codebook as a subset or subcodebook of a multi-carrier codebook.

For the following example, the hamming distance between each codeword pair is also enhanced to achieve a minimum hamming distance of 4. More specifically, for the second example code embodiment, the multi-carrier codebook 312, which may be implemented using one HS-DPCCH for DC-HSDPA HARQ acknowledgment signaling, is described. The codebook may have the following example values for each of the codewords:

ACK/DTX＝ [1 1 1 1 1 1 1 1 1 1]

NACK/DTX＝ [0 0 0 0 0 0 0 0 0 0]

DTX/ACK＝ [1 1 1 1 1 0 0 0 0 0]

DTX/NACK＝ [0 0 0 0 0 1 1 1 1 1]

NACK/ACK＝ [1 1 0 0 1 1 0 0 1 1]

ACK/NACK＝ [0 0 1 1 0 0 1 1 0 0]

ACK/ACK＝ [1 0 1 0 1 0 1 0 1 0]

NACK/NACK＝[0 1 0 1 0 1 0 1 0 1]。

the minimum hamming distance for this example codebook is 4.

Furthermore, the second example code present embodiment may be augmented by a Preamble (PRE) and Postamble (POST) legacy codeword as defined in releases 5, 6 and 7. These legacy values for PRE and POST codewords are as follows:

PRE＝ [0 0 1 0 0 1 0 0 1 0]

POST＝[0 1 0 0 1 0 0 1 0 0]。

with this second example code embodiment, if the remote terminal misses an order to stop multi-carrier operation (e.g., misses an HS-SCCH order) and remains in multi-carrier operation (e.g., remains in DC-HSDPA operation), it will signal an ACK/DTX codeword indication or a NACK/DTX codeword indication when it acknowledges receipt of HS-DSCH data. Since these two codewords are identical to the ACK and NACK codewords for single carrier (including single cell) signaling, there is no ambiguity problem at the radio network node.

In addition, given the codebook configuration of the second example code embodiment, messages with the opposite meaning are assigned the largest (paired) codeword separation. For example, the messages DTX/ACK and DTX/NACK have opposite meanings. The messages ACK/DTX and NACK/DTX also have opposite meanings. In addition, the messages ACK/ACK and NACK/NACK have (double) opposite meanings. The messages ACK/NACK and NACK/ACK also have (double) opposite meanings. It can be seen that the proposed codebook has a hamming distance of 10 for each pair of the above opposite meaning cases.

Codeword remapping (e.g., altering the definition of a codeword), bit permutation, bit-wise masking, combinations thereof, and the like produces a codebook with enumerated properties. Thus, a codebook that can be obtained by one or more of these and/or similar or analogous operations (e.g., at the beginning of a codebook as described herein) includes an equivalent codebook. Example implementations of these operations are provided below.

As a first example, the definitions of two or more pairs of codewords can be remapped. For example, the two codewords [1100110011] and [0011001100] (for NACK/ACK and ACK/NACK) may be transformed to produce the following equivalent codebook:

ACK/DTX＝ [1 1 1 1 1 1 1 1 1 1]

NACK/DTX＝ [0 0 0 0 0 0 0 0 0 0]

DTX/ACK＝ [1 1 1 1 1 0 0 0 0 0]

DTX/NACK＝ [0 0 0 0 0 1 1 1 1 1]

NACK/ACK＝ [0 0 1 1 0 0 1 1 0 0]

ACK/NACK＝ [1 1 0 0 1 1 0 0 1 1]

ACK/ACK＝ [1 0 1 0 1 0 1 0 1 0]

NACK/NACK＝[0 1 0 1 0 1 0 1 0 1]

PRE＝ [0 0 1 0 0 1 0 0 1 0]

POST＝ [0 1 0 0 1 0 0 1 0 0]。

however, this codeword remapping does not alter the basic code properties of the codebook, such as the minimum hamming distance 4. Furthermore, a (pairwise) maximum hamming distance 10 is reserved between code pairs having opposite meaning. In other words, a hamming distance of 10 is reserved between code pairs DTX/ACK and DTX/NACK, between code pairs ACK/DTX and NACK/DTX, between code pairs ACK/NACK and NACK/ACK and between code pairs ACK/ACK and NACK/NACK.

As another example, permuting columns in the "original" codebook does not alter the base code properties. For example, converting the first and last columns of the "original" second example code embodiment yields an equivalent codebook as follows:

ACK/DTX＝ [1 1 1 1 1 1 1 1 1 1]

NACK/DTX＝ [0 0 0 0 0 0 0 0 0 0]

DTX/ACK＝ [0 1 1 1 1 0 0 0 0 1]

DTX/NACK＝ [1 0 0 0 0 1 1 1 1 0]

NACK/ACK＝ [1 1 0 0 1 1 0 0 1 1]

ACK/NACK＝ [0 0 1 1 0 0 1 1 0 0]

ACK/ACK＝ [0 0 1 0 1 0 1 0 1 1]

NACK/NACK＝[1 1 0 1 0 1 0 1 0 0]

PRE＝ [0 0 1 0 0 1 0 0 1 0]

POST＝ [0 1 0 0 1 0 0 1 0 0]

this bit permuted codebook preserves the minimum hamming distance 4 of the codebook. Also, a hamming distance of 10 is reserved between the code pairs DTX/ACK and DTX/NACK, between the code pairs ACK/DTX and NACK/DTX, between the code pairs ACK/NACK and NACK/ACK and between the code pairs ACK/ACK and NACK/NACK.

As yet another example, applying a public mask to the "original" second example code does not alter the base code properties of this embodiment. For example, a public mask of [1001001000] can be applied to each codeword in the "original" codebook to produce the following equivalent codebook:

ACK/DTX＝ [0 1 1 0 1 1 0 1 1 1]

NACK/DTX＝ [1 0 0 1 0 0 1 0 0 0]

DTX/ACK＝ [0 1 1 0 1 0 1 0 0 0]

DTX/NACK＝ [1 0 0 1 0 1 0 1 1 1]

NACK/ACK＝ [0 1 0 1 1 1 1 0 1 1]

ACK/NACK＝ [1 0 1 0 0 0 0 1 0 0]

ACK/ACK＝ [0 0 1 1 1 0 0 0 1 0]

NACK/NACK＝[1 1 0 0 0 1 1 1 0 1]

PRE＝ [1 0 1 1 0 1 1 0 1 0]

POST＝ [1 1 0 1 1 0 1 1 0 0]。

this codebook resulting from the application of the common mask preserves the minimum hamming distance 4 of the codebook. Also, a hamming distance of 10 is reserved between the code pairs DTX/ACK and DTX/NACK, between the code pairs ACK/DTX and NACK/DTX, between the code pairs ACK/NACK and NACK/ACK and between the code pairs ACK/ACK and NACK/NACK.

Fig. 5 is a flow diagram 500 of an example general method for multi-carrier acknowledgement signaling. As shown, the flow diagram 500 includes eight blocks 502-516. The flowchart 500 may be implemented by two communication devices, such as a first device 302a and a second device 302b (fig. 3). In an example embodiment, the first apparatus 302a implements steps 502, 504, 514, and 516 as the radio network node 102. The second device 302b implements step 506 and 512 as the remote terminal 104.

The steps of flowchart 500 may be implemented by processor-executable instructions. Processor-executable instructions may be implemented in hardware, firmware, software, fixed logic circuitry, combinations thereof, and the like. Example operational implementations of processor-executable instructions include, but are not limited to, a memory coupled to a processor, an Application Specific Integrated Circuit (ASIC), a digital signal processor and associated code, some combination thereof, and so forth.

In an example embodiment, flow diagram 500 illustrates a method for implementing acknowledgement signaling in a multi-carrier environment using a multi-carrier codebook 312. Although specific example elements from other figures are referenced to describe the steps of fig. 5, the steps may alternatively be performed by other elements.

At step 502, an indication of downlink scheduling and carrier mode is transmitted. For example, the wireless network node 102 may transmit an indication of the downlink schedule and carrier mode to the remote terminal 104a using the transmitter 304 a. The carrier mode may be, for example, a single carrier mode or a multi-carrier mode (e.g., a dual carrier mode). Downlink scheduling typically informs remote terminals of bandwidth assignment blocks (e.g., frequencies and/or time slots).

At step 504, downlink communications are transmitted on one or more carriers. For example, the wireless network node 102 may transmit the downlink communication 106 to the remote terminal 104a on one or more carriers using the transmitter 304a according to the indicated carrier mode and downlink schedule.

The remote terminal 104a receives, or at least attempts to receive, the downlink communication 106 from the wireless network node 102 using the receiver 306 b. At step 506, it is determined whether downlink communications are received on the intended carrier. For example, the communication validation unit 308b of the remote terminal 104a may determine whether the downlink communication 106 is received on the expected carrier based on the indicated carrier mode and the downlink schedule.

At step 508, a reception situation is determined. For example, in the dual carrier case, the communication validation unit 308b of the remote terminal 104a may determine the reception situation. The reception situation corresponds to whether the communication was correctly received on the expected carrier and whether the communication was expected on the carrier. Thus, determining the reception situation determines whether an ACK, NACK, DTX, etc., indicates suitability for each assigned carrier. For a particular example, if the communication is expected on both the first and second carriers, and if the communication is correctly received only on the first carrier, the reception scenario corresponds to an ACK for the first carrier and a NACK for the second carrier.

From the multi-carrier codebook, a codeword is determined having a meaning corresponding to the determined reception situation, step 510. For example, from the multi-carrier codebook 312 stored in the memory of the remote terminal 104a, the communication validation unit 308b of the remote terminal 104a may determine a codeword having a meaning corresponding to the determined reception scenario. Continuing with the specific example in the dual-carrier context, remote terminal 104a determines the value of codeword 402f in dual-carrier codebook 312-2 that corresponds to the ACK/NACK meaning.

At step 512, the message with the determined codeword is transmitted. For example, the transmitter 304b may be used to transmit the uplink response message 108 with the determined codeword 402 from the remote terminal 104a to the wireless network node 102. At step 514, a message with the determined codeword is received. For example, the uplink response message 108 with the determined codeword 402 may be received at the wireless network node 102 from the remote terminal 104a using the receiver 306 a.

At step 516, the received codeword is decoded. For example, using the copy of the multicarrier codebook 312 stored in the memory of the wireless network node 102, the communication validation unit 308a of the wireless network node 102 may decode the received codeword 402. Decoding transforms or extracts acknowledgement meaning from the values of the received codeword 402. Continuing with this particular example, the communication validation unit 308a of the wireless network node 102 decodes the value of the received codeword 402f to extract the expected ACK/NACK meaning acknowledging the reception situation on the first and second carriers.

Fig. 6A is a block diagram 600A illustrating a hamming distance analysis 602 performed on an example multi-carrier codebook 312. As shown, the block diagram 600A includes a multi-carrier codebook 312, a hamming distance analysis 602, and a minimum hamming distance 604. Generally, the hamming distance analysis 602 is applied to the multi-carrier codebook 312. The result of the analysis is a minimum hamming distance 604.

As described herein above, the multi-carrier codebook 312 according to the first exemplary code embodiment achieves a minimum hamming distance 604 equal to five (5). The equivalent manipulation of this codebook similarly maintains a minimum hamming distance of 5. The multi-carrier codebook 312 of the present embodiment according to the second exemplary code achieves a minimum hamming distance 604 equal to four (4). The equivalent manipulation of this codebook similarly maintains a minimum hamming distance of 4.

Fig. 6B is a block diagram 600B illustrating an example codeword pair 606 with opposite meanings. As shown, the diagram 600B includes four codeword pairs 606, eight codewords 402, and a maximum codeword separation indication 608. Each codeword pair 606 includes two codewords 402 having opposite meanings.

The codeword pair 606ab includes a codeword 402a (ACK/DTX) and a codeword 402b (NACK/DTX). The codeword pair 606cd includes a codeword 402c (DTX/ACK) and a codeword 402d (DTX/NACK). Codeword pair 606ef includes codeword 402e (NACK/ACK) and codeword 402f (ACK/NACK). The codeword pair 606gh includes a codeword 402g (ACK/ACK) and a codeword 402h (NACK/NACK).

For at least the second example code present embodiment, the codeword separation is configured to be a maximum codeword separation 608 between any two codewords 402 of a codeword pair 606 in which the included codewords have opposite meanings. For example, there is a maximum codeword separation 608 between codeword pair 402a and 402 b. Similarly, there is a maximum codeword separation 608 between codeword pair 402e and 402 f. For a codebook having codewords 402 of length 10, the maximum codeword separation 608 is 10.

With the second example code embodiment, the remote terminal is able to signal a positive acknowledgement (or negative acknowledgement) of MC-HSDPA HARQ using a different codebook than the single carrier codebook of the same system. The multi-carrier (including multi-cell) codebook contains the codebook for single-carrier (including single-cell) HARQ acknowledgment signaling as its sub-codebook. Furthermore, the pair-wise hamming distance of the new codebook is enhanced under the sub-codebook constraint. This scheme can be extended to cover the case of MIMO extension to multi-carrier (or multi-cell) operation.

In another example embodiment, for CQI reporting in a dual carrier environment, the remote terminal is to use the DC-HSDPA HS-DPCCH format regardless of whether an HS-SCCH order is received to deactivate DC-HSDPA operation. With such an embodiment, there would be excess bits for the second CQI field. These excess bits in the second CQI field may be used in any of a number of different manners.

An example use of the spare bits of the second CQI field is described as follows. First, the CQI for the second carrier may be measured and reported even if the radio network node will not currently schedule the remote terminal on the second carrier. These reported measurements may still be used by the radio network node. For example, the wireless network node may determine whether it is appropriate to reactivate DC-HSDPA operation.

Second, the CQI for the first carrier may be reported twice in order to achieve some repetition coding of the CQI. This repetition coding may improve the uplink coverage of the CQI information. Third, an unassigned/unused CQI value (e.g., a currently unused value of 31) may be reported to indicate to the wireless network node that the remote terminal assumes that DC-HSDPA operation is currently disabled. Alternatively, the CQI may be encoded using two (10, 5) codes (i.e., one per carrier/cell).

Certain implementations may involve a combination of DC-HSDPA features and MIMO HSDPA features. In such implementations, the new format may be utilized. For an example embodiment of such a format, information corresponding to a first MIMO stream may be mapped to a first HS-DPCCH code, and information corresponding to a second MIMO stream may be mapped to a second HS-DPCCH code. The first HS-DPCCH code may be similar to the DC-HSDPA HS-DPCCH format described above. The second HS-DPCCH code may be transmitted in parallel with the first HS-DPCCH code.

Fig. 7 is a block diagram 700 of an example apparatus 702 that can be employed to implement an embodiment of multi-carrier acknowledgement signaling. As shown, the block diagram 700 includes two devices 702a and 702b, a human-device interface apparatus 712, and one or more networks 716. As explicitly shown by the devices 702a, each device 702 may include at least one processor 704, one or more memories 706, one or more input/output interfaces 708, and at least one interconnect 714. The memory 706 may include processor-executable instructions 710. The network 716 may be, by way of example and not limitation, the internet, an intranet, an ethernet, a public network, a private network, a cable network, a Digital Subscriber Line (DSL) network, a telephone network, a wired network, a wireless network, some combination thereof, and so forth. The device 702a and the device 702b may communicate over a network 716.

For the example embodiment, the device 702 may represent any processing-capable device. The processor 704 may be implemented using any suitable processing-capable technology and may be implemented as a general-purpose or special-purpose processor. Examples include, but are not limited to, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), a microprocessor, some combination thereof, and so forth. Memory 706 can be any available memory included as part of device 702 and/or accessible by device 702. Including volatile and non-volatile memory, removable and non-removable memory, hard-coded logic, combinations thereof, and so forth.

Interconnect 714 interconnects the components of apparatus 702. Interconnect 714 may be implemented as a bus or other connection mechanism and may directly or indirectly interconnect the various components. The I/O interfaces 708 include (I) a network interface for communicating and/or monitoring across the network 716, (ii) a display device interface for displaying information on a display screen, (iii) one or more human-device interfaces, and so forth. Example network interfaces include, but are not limited to, a radio or transceiver (e.g., transmitter and/or receiver), a modem, a network card, some combination thereof, and so forth. The human-device interface apparatus 712 may be integrated with or separate from the device 702.

Generally, the processor 704 is capable of executing, and/or otherwise carrying out processor-executable instructions, such as processor-executable instructions 710. The memory 706 is comprised of memory accessible by one or more processors. In other words, the memory 706 may include processor-executable instructions 710 that are executable by the processor 704 to perform the execution of functions by the device 702. The processor-executable instructions 710 may be implemented as software, firmware, hardware, fixed logic circuitry, some combination thereof, and so forth. The processor 704 and the processor-executable instructions 710 of the memory 706 may be implemented separately (e.g., as DSP executing code) or integrated (e.g., as part of an Application Specific Integrated Circuit (ASIC)).

In an example implementation, one apparatus 702 may comprise a first apparatus 302a (e.g., wireless network node 102) and another apparatus 702 may comprise a second apparatus 302b (e.g., remote terminal 104) (of fig. 1 and 3). The processor-executable instructions 710 may include, for example, the components and/or units of fig. 3, 4, 6A, and 6B (e.g., the communication validation unit 308, the multicarrier codebook 312, etc.). The processor-executable instructions 710, when executed by the processor 704, may perform the functions described herein. Example functions include, but are not limited to, those illustrated by flowchart 500 (of fig. 5) and those that can be implemented by the example multi-carrier codebook described above herein as well as those implemented by other features described herein.

Various embodiments of the invention may provide one or more advantages. In general, certain embodiments achieve an enhanced minimum hamming distance for codebooks having codewords that jointly encode ACK/NACK signaling for multiple carriers. Another advantage of certain embodiments is that PRE and POST operations may be supported (e.g., by including a preamble code word and a postamble code word that are compatible with one or more previous releases of the wireless standard). More specifically, for the first example code embodiment, a multi-carrier codebook with a total of ten codewords achieves a minimum hamming distance 5 across a total of 10 codewords, 5 being the maximum possible minimum hamming distance for any codebook with 10 codewords of length 10.

For the second example embodiment, a multi-carrier codebook with eight codewords achieves a minimum hamming distance of 4 between any two codeword pairs (e.g., excluding the preamble and postamble codewords). Moreover, another advantage of these embodiments is that codebook ambiguity can be avoided when the remote terminal fails to detect the HS-SCCH order because the multi-carrier codebook can be configured to include the single-carrier codebook as a subset or sub-codebook thereof. Yet another advantage of some embodiments is that maximum codeword separation can be achieved for messages with opposite meaning.

The devices, features, functions, methods, steps, schemes, data structures, procedures, components, etc. of fig. 1-7 are illustrated in the figures as separate blocks and other elements. However, the order, interconnections, interrelationships, layout, etc. in which fig. 1-7 are described and/or illustrated are not intended to be construed as limiting, as any number of the blocks and/or other elements may be modified, combined, rearranged, augmented, omitted, etc. in any manner in order to implement one or more systems, methods, apparatus, memories, devices, arrangements, etc. for multi-carrier acknowledgement signaling.

Although several embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, since various rearrangements, modifications and substitutions can be made therein without departing from the scope of the invention as set forth and defined by the following claims.

Claims (26)

1. A method in a remote terminal for acknowledgment uplink signaling in a multi-carrier mode, the method comprising:

determining a codeword from a multi-carrier codebook stored in at least one memory of the remote terminal to jointly encode acknowledgement signaling for at least two carriers; the multi-carrier codebook comprises at least eight codewords defined as a single-carrier codebook having a sub-codebook of the multi-carrier codebook, each of the eight codewords having a length of ten; the multi-carrier codebook achieves a minimum Hamming distance of four between the at least eight codewords; and the number of the first and second groups,

transmitting an uplink signaling message including the determined codeword from the remote terminal to a radio network node.

2. The method of claim 1, wherein the multi-carrier mode comprises a dual-carrier mode; and wherein the at least eight codewords have the following eight meanings: ACK/DTX, NACK/DTX, DTX/ACK, DTX/NACK, NACK/ACK, ACK/NACK, ACK/ACK and NACK/NACK.

3. The method of claim 2, wherein the at least two carriers comprise a first carrier and a second carrier; and wherein the ACK/DTX corresponds to a positive acknowledgement for the first carrier and no reception for the second carrier, the NACK/DTX corresponds to no reception for the first carrier and no reception for the second carrier, the DTX/ACK corresponds to no reception for the first carrier and no acknowledgement for the second carrier, the DTX/NACK corresponds to no reception for the first carrier and no acknowledgement for the second carrier, the NACK/ACK corresponds to a negative acknowledgement for the first carrier and a positive acknowledgement for the second carrier, the ACK/NACK corresponds to a positive acknowledgement for the first carrier and a negative acknowledgement for the second carrier, the ACK/ACK corresponds to a positive acknowledgement for the first carrier and a positive acknowledgement for the second carrier, and the NACK/NACK corresponds to a negative acknowledgement for the first carrier and a negative acknowledgement for the second carrier.

4. The method of claim 1, wherein the multi-carrier codebook maximizes a pair-wise hamming distance attribute for codewords having opposite meanings.

5. The method of claim 4, wherein the multi-carrier mode comprises a dual-carrier mode; and wherein the following codeword pairs from the multi-carrier codebook have opposite meanings: discontinuous transmission of DTX/acknowledgement ACK and DTX/negative acknowledgement NACK; ACK/DTX and NACK/DTX; ACK/ACK and NACK/NACK; and ACK/NACK and NACK/ACK.

6. The method of claim 1, wherein the multi-carrier codebook further comprises a preamble codeword and a postamble codeword compatible with at least one legacy single-carrier version of preamble and postamble codewords.

7. The method of claim 1, wherein the multi-carrier codebook has the single-carrier codebook as its sub-codebook, such that accurate uplink signaling can be achieved even when the apparatus receiving the uplink signaling message and the apparatus transmitting the uplink signaling message do not match with respect to the single-carrier codebook relative to the multi-carrier version.

8. The method of claim 1, wherein a sub-codebook of the multi-carrier codebook corresponding to the single-carrier codebook comprises (i) an acknowledgement ACK/Discontinuous Transmission (DTX) codeword corresponding to an ACK codeword and (ii) a Negative Acknowledgement (NACK)/DTX codeword corresponding to a NACK codeword.

9. The method according to claim 1, wherein the step of transmitting an uplink signaling message comprises the step of transmitting the uplink signaling message comprising the determined codeword on a high speed dedicated physical control channel, HS-DPCCH.

10. The method of claim 1, further comprising the step of transmitting at least first and second channel quality indicator, CQI, fields when multi-carrier mode is deactivated.

11. The method of claim 10, wherein the second CQI field comprises a CQI for a second carrier.

12. The method of claim 10, wherein the first CQI field and the second CQI field each comprise a CQI for a first carrier.

13. The method of claim 10, wherein the second CQI field comprises a value indicating that the multi-carrier mode is disabled.

14. The method of claim 1, further comprising the steps of:

mapping information corresponding to a first multiple-input multiple-output, MIMO, stream to codewords from the multi-carrier codebook for a first codeword message; and

mapping information corresponding to a second MIMO stream to codewords from the multi-carrier codebook for a second codeword message;

wherein the step of transmitting an uplink signaling message comprises the step of transmitting the first codeword message in parallel with the second codeword message.

15. The method according to claim 1, wherein automatic repeat request uplink signaling comprises hybrid automatic repeat request, HARQ, uplink signaling.

16. The method of claim 1, wherein the multi-carrier mode comprises a multi-cell mode in which a first carrier of the at least two carriers is associated with a first cell and a second carrier of the at least two carriers is associated with a second cell.

17. The method of claim 1, further comprising the steps of:

determining whether one or more downlink communications are received on one or more expected carriers; and the number of the first and second groups,

determining a reception situation based on the one or more downlink communications and the one or more expected carriers;

wherein the step of determining a codeword comprises the step of determining from the multicarrier codebook a codeword having a meaning corresponding to the determined reception situation.

18. A remote terminal adapted to perform acknowledgment uplink signaling in a multi-carrier mode, the remote terminal comprising:

at least one memory storing a multi-carrier codebook; the multi-carrier codebook comprises at least eight codewords defined to have a single-carrier codebook as a sub-codebook of the multi-carrier codebook, each codeword of the eight codewords having a length of ten; the multi-carrier codebook achieves a minimum Hamming distance of four between the at least eight codewords; and

one or more processors to:

determining from the multi-carrier codebook a codeword for jointly encoding acknowledgement signaling for at least two carriers; and the number of the first and second groups,

transmitting an uplink signaling message including the determined codeword from the remote terminal to a radio network node.

19. The remote terminal of claim 18, wherein the multi-carrier mode comprises a dual-carrier mode; and wherein the at least eight codewords have the following eight meanings: ACK/DTX, NACK/DTX, DTX/ACK, DTX/NACK, NACK/ACK, ACK/NACK, ACK/ACK and NACK/NACK.

20. The remote terminal of claim 18, wherein the multi-carrier code maximizes a pair-wise hamming distance attribute for codewords having opposite meanings.

21. The remote terminal of claim 20, wherein the multi-carrier mode comprises a dual-carrier mode; and wherein the following codeword pairs from the multi-carrier codebook have opposite meanings: discontinuous transmission of DTX/acknowledgement ACK and DTX/negative acknowledgement NACK; ACK/DTX and NACK/DTX; ACK/ACK and NACK/NACK; and ACK/NACK and NACK/ACK.

22. The remote terminal of claim 18, wherein the multi-carrier codebook further comprises a preamble codeword and a postamble codeword compatible with at least one legacy single-carrier version of preamble and postamble codewords.

23. The remote terminal of claim 18, wherein the multi-carrier mode comprises a multi-cell mode in which a first carrier of the at least two carriers is associated with a first cell and a second carrier of the at least two carriers is associated with a second cell.

24. A method in a radio network node for acknowledgement uplink signaling in a multi-carrier mode, the method comprising the steps of:

receiving, at the radio network node, an uplink signaling message from a remote terminal, the uplink signaling message comprising a codeword jointly encoding acknowledgement signaling for at least two carriers; and

decoding the codeword using a multi-carrier codebook stored in at least one memory of the wireless network node; the multi-carrier codebook comprises at least eight codewords defined to have a single-carrier codebook as a sub-codebook of the multi-carrier codebook, each codeword of the eight codewords having a length of ten; the multi-carrier codebook achieves a minimum hamming distance of four between the at least eight codewords.

25. A radio network node adapted to perform acknowledgment uplink signaling in a multi-carrier mode, the radio network node comprising:

at least one memory storing a multi-carrier codebook; the multi-carrier codebook comprises at least eight codewords defined to have a single-carrier codebook as a sub-codebook of the multi-carrier codebook, each codeword of the eight codewords having a length of ten; the multi-carrier codebook achieves a minimum Hamming distance of four between the at least eight codewords; and

one or more processors to:

receiving, at the radio network node, an uplink signaling message from a remote terminal, the uplink signaling message comprising a codeword jointly encoding acknowledgement signaling for at least two carriers; and

decoding the codeword using a multi-carrier codebook.

26. A method in a remote terminal for acknowledgment uplink signaling in a multi-carrier mode, the method comprising:

determining a codeword from a multi-carrier codebook stored in at least one memory of the remote terminal to jointly encode acknowledgement signaling for at least two carriers; the multi-carrier codebook comprises at least eight codewords plus a preamble codeword and a postamble codeword, the preamble codeword and the postamble codeword being compatible with at least one legacy single-carrier version of the preamble and postamble codewords, each of the eight codewords having a length of ten; the multi-carrier codebook achieves a minimum hamming distance of five across the eight codewords and the pre-and post-synchronization codewords; and the number of the first and second groups,

transmitting an uplink signaling message including the determined codeword from the remote terminal to a radio network node.