Method, device and system for assigning ack channels to users

ES 2 643 597 T3

DESCRIPTION

Device and system to assign ACK channels to users

Field of the invention

The present invention relates to the field of mobile communications and, more particularly, to a technique for assigning acknowledgment channels (ACK) to a user.

Background of the invention

In an evolved universal terrestrial radio access system (E-UTRA) of the Project of Association of 3^toGeneration (3GPP), a network side equipment, for example a base station (BS), provides downlink control signaling before sending downlink data in order to instruct a user to receive the data downlink from corresponding resources. After receiving the downlink data, the user reports an acknowledgment (ACK) if the downlink data is received correctly; otherwise, the user reports a negative acknowledgment (NAK). The user equipment (UE) receiving the downlink data can support two modes, namely a frequency division duplexing (FDD) mode and a time division duplexing (TDD) mode.

As for the UE that supports TDD mode, the channels that carry the user's ACK / NAK notification information are ACK channels. ACK channels are assigned by the network side according to a rule predefined by the system. The user has already acquired the predefined rule and detects the assigned ACK channels according to the predefined rule, and then transports the notification information on the channels and sends the notification information to the equipment on the network side.

In the prior art, a frame structure in TDD mode is generally as shown in FIG. 1. Each radio frame is 10 ms long and consists of two half-frames that are respectively 5 ms long. Each half-frame consists of eight slots that are respectively 0.5 ms long and have three special fields, DwPTS, GP, and UpPTS. Each pair of slots constitutes a subframe, and the three special fields, DwPTS, GP, and UpPTS constitute a special subframe. Each subframe is 1 ms long. Among the subframes, subframes 0 and 5 are downlink subframes, subframe 2 is an uplink subframe, DwPTS in the special subframe may transmit downlink data or may not transmit data, and the remaining subframes may be assigned in a flexible as uplink subframes or downlink subframes.

Currently, there are seven downlink to uplink configurations defined in the 3GPP E-UTRA system, including three configurations for 5 ms downlink to uplink switching point periodicity, namely 1: 3, 2 : 2 and 3: 1; and four settings for the 10 ms downlink to uplink switch point periodicity, namely 6: 3, 7: 2, 8: 1 and 3: 5. Except for the two ratios 1: 3 and 3: 5, all other ratios are required to report ACKs or NAKs of N (N> 1, N is an integer) downlink subframes in an uplink subframe. As those skilled in the art know, N> 1 is a unique condition for TDD mode, and it is necessary to solve the ACK / NAK assignment problem for a plurality of downlink subframes under this condition. On the other hand, the solutions proposed under the condition of N> 1 should also satisfy the condition of N = 1 in order to reduce the complexity of the system in TDD mode.

Since the time-frequency resources occupied by a physical downlink control channel (PDCCH) are measured by taking control channel elements (CCE) as unity, an ACK channel for the uplink notification of ACK or NAK is it is implicitly mapped by a CCE to the smallest label occupied by the PDCCH. A commonly used implicit mapping mode is a one-to-one mapping of CCE tags to ACK tags.

In the 3GPP system, the number of symbols n occupied by the PDCCH as indicated by a control format indicator physical channel (PCFICH) in each downlink subframe can be 1, 2 or 3; and as for the special subframe, n can be 1 or 2. The value of n for each subframe varies dynamically. In a downlink subframe, in the given system, parameters such as system bandwidth and pilot antenna configuration remain constant, and the greater the number n of symbols occupied by the PDCCH, the more CCE there will be in the subframe. downlink. When n is 1, 2, and 3, the number of CCEs in the downlink subframe is represented by Ncce, -¡ Ncce, 2 and Ncce, 3, and Ncce, -¡ <Ncce, 2 <Ncce, 3.

According to the prior art, when it is necessary to report the ACK / NAK of N downlink subframes in one uplink subframe, the network side allocates ACK channels to the user according to the following rule.

(1) Considering that n can be provided with different values, the network side reserves f (NccE, 3) ACK channels for each downlink subframe (including the special subframe) according to the maximum number of

ES 2 643 597 T3

CCE, and correlates CCEs with ACKs one by one, where f (NccE, 3) = Ncce, 3 · The function f represents a correlation rule between CCE labels and ACK channel labels. For N subframes, a total number of N * Ncce is reserved, 3 channels aCk.

(2) The N * Ncce, 3 ACK channels are divided into N consecutive parts and each downlink subframe is mapped to one part according to the original sequence, and each part is Ncce, 3 in size. For example, when it is required to report the ACK / NAKs of two downlink subframes in one uplink subframe, a corresponding correlation mode is as shown in FIG. 2, where the maximum PCFICH values ​​of the downlink subframes 0 and 1 are equal to 3.

3GPP document R1-081219 (Samsung, 03/26/2008) discloses a correlation rule of CCE with uplink ACK / NAK. In the proposed correlation rule, the N ACK / NAKs are divided into K parts, and the K-th part consists of indices j * K + k of ACK / NAK, where k = 0, 1, ..., K-1 ; each part is mapped to a downlink subframe individually.

3GPP document R1-081257 (LG Electronics, 04/09/2008) discloses CCE index related uplink ACK / NAK resource allocation procedures for downlink allocation in E-UTRA mode. In the proposed procedures, an uplink subframe carries the ACK / NACKs of multiple downlink subframes, and the ACK / NAK resources are divided by multiple subsets, so that the ACK / NACK resources of each subset are linked, exclusively, to a downlink subframe.

When implementing the aforementioned techniques, the inventor (s) has found that when ACK channels are assigned to a user according to the above rules, the unused ACK channels cannot be effectively freed to form blocks of resources (RB) for uplink shared physical channel (PUSCH) transmission.

Summary of the invention

The present invention provides a technique for assigning ACK channels to a user in order to save required ACK channel resources. The embodiment of the invention and the technical solution of the present disclosure are made as disclosed in the independent claims.

An exemplary allocation unit is provided in a device for allocating acknowledgment channels, ACK, to a user according to a pre-acquired rule, where ACK channels are used to report ACK information of N downlink subframes in an uplink subframe; where the ACK channels are assigned: dividing the ACK channels into N blocks, where each downlink subframe of the N downlink subframes corresponds to a block in a preset sequence, where the preset sequence is a sequence that places a special subframe in a last position, or the preset sequence is a sequence that places the subframe with the maximum actual value of n in a leading position; dividing each block into max {M /} or My sub-blocks, where the sub-blocks that belong to different blocks are interleaved and the sub-blocks that are from the different blocks and are correlated with the same set of control channel elements, CCE, of different subframes are arranged sequentially according to the predetermined sequence; and assigning the ACK channels to the downlink subframes by mapping sets of CCEs that have labels of {0, 1, ..., Ncce, 1 -1}, {Ncce, 1, Ncce, 1 +1, ..., Ncce, 2 -1}, ..., {NccE, max {M /} - 1, NccE, max {M /} - 1 +1, ..., NccE, max {M /} -1} within each downlink subframe with the max {M /} subblocks of the block associated with the downlink subframe of label i; or by assigning the ACK channels to the downlink subframes by mapping the CCE sets that have labels of {0, 1, ..., Ncce, 1 -1}, {Ncce, 1, Ncce, 1 +1, ... , Ncce, 2 -1}, ..., {Ncce, me-1, Ncce, me-1 +1, ..., Ncce.my -1} within each downlink subframe with the Mi sub-blocks of the block associated with the downlink subframe of tag i; where N is a positive integer, Mi represents a maximum possible value of n for a downlink subframe with a label of i among N downlink subframes, i = 0, 1, ..., N-1, the max value {M /} represents a maximum value of Mi, NccE, max {M /} represents the number of CCEs in the downlink subframe when n is equal to max {M /}, Ncce, me represents the number of CCEs in the downlink subframe when n equals Mi, and n is the number of symbols occupied by a physical downlink control channel, PDCCH.

An exemplary communication system includes the device comprising the above allocation unit.

The embodiments of the present invention are based on the following: The reserved ACK channels are divided into blocks according to the downlink sub-frames, each block is divided into a plurality of sub-blocks, and the sets of CCEs within the same sub-frame are respectively mapped to different sub-blocks in order to free up non-ACK channel resources. used as complete blocks to form more RBs for transmission of other channels, for example PUSCH transmission. Alternatively, the ACK channels are consecutively correlated with each subframe among the reserved ACK channels in order to release the unused ACK channel resources as full blocks, thereby saving ACK channel resources. Alternatively, a plurality of consecutive CCEs are mapped to an ACK channel, or a plurality of subframes

ES 2 643 597 T3 downlink is assigned with the same correlation label in order to reduce resource reservation overhead, thus saving ACK channel resources.

Brief description of the drawings

The present invention is described in detail below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a frame structure in a TDD mode in the prior art;

FIG. 2 is a schematic view of a prior art correlation mode;

FIG. 3 is a schematic flow diagram of a method according to an embodiment of the present invention;

FIG. 4 is a schematic view of a correlation mode according to an embodiment of the present invention;

FIG. 5 is a schematic view of another mode of correlation according to an embodiment of the present invention;

FIG. 6 is a schematic view of yet another mode of correlation according to an embodiment of the present invention;

FIG. 7 is a schematic structural view of a device according to an embodiment of the present invention; and FIG. 8 is a schematic structural view of a system according to an embodiment of the present invention.

Detailed description of the embodiments

During the process of implementing the embodiments of the present invention, the inventor (s) have observed that when ACK channels are assigned to a user according to the prior art, the unused ACK channels cannot be released. effectively to form RB for PUSCH transmission. For example, when the ACK / NAKs of two downlink subframes are reported in one uplink subframe and an actual value of n indicated by the PCFICH of subframe 0 is 1, the ACK channel labels that can actually be used between ACK channels with labels of 0 ~ NCCE, 3-1 that are correlated to subframe 0 may simply be in the range of 0 ~ NCCE, 1-1, and the other ACK channels with labels of NCCE, 1 ~ NCCE, 3-1 cannot be occupied by implicit mapping. As a result, the resources occupied by such unused ACK channels cannot be released as full blocks, that is, it is difficult for the idle resources to form RBs once released.

In one embodiment of the present invention, as shown in FIG. 3, when it is necessary to report the ACK / NAK of N downlink subframes in one uplink subframe, the network side allocates ACK channels to the user according to the following rule.

In step 101, ACK channels are reserved for each downlink subframe. Considering that the value of n for each subframe varies dynamically, NccE, max {Mi} ACK channels are reserved for each subframe (including the special subframe), so that a total number of N * NccE, max {Mi} channels are reserved . In this case, Mi represents a maximum possible value of n for a downlink subframe with a label of i among N downlink subframes; i = 0, 1, ..., N-1; max {Mi} represents a maximum value of Mi; and Ncce, max {M¡} represents the number of CCEs in the downlink subframe when n is equal to max {Mi}.

For example, in the current 3GPP E-UTRA system, as far as the special subframe is concerned, n has a maximum value of 2, that is, Mi = 2; and for the other subframes, n has a maximum value of 3, that is, Mi = 3, so that max {Mi} is 3. The number of ACK channels reserved for each subframe is Ncce, 3.

In step 102, the CCEs of N subframes are mapped to the reserved ACK channels. Specifically, the reserved ACK channels are divided into N blocks, and each block is divided into max {My} sub-blocks. Regarding N downlink subframes, each subframe corresponds to a block in a predetermined sequence; and sets of CCE with labels of {0, 1, ..., Ncce, i-1}, {Ncce, i, Ncce, i +1, Ncce, 2 -1}, {NccE, max {Mi} -i , NccE, max {M¡} -1 +1, ..., NccE, max {M¡} -1} within the same subframe are respectively correlated with different sub-blocks.

The specific correlation process of step 102 is illustrated below taking the 3GPP E-UTRA system with max {Mi} = 3 as an example. Max {Mi} = 3, that is, each block is divided into 3 sub-blocks. The sets of CCE with labels of {0, 1, ..., Ncce, i-1}, {Ncce, i, Ncce, i + 1, ..., (Ncce, 2 -1)}, {Ncce, 2, (Ncce, 2 + 1), ..., (Ncce, 3 -1)} within the same subframe are respectively correlated with different subblocks.

In the correlation process, a subframe with a label of i (0 <i <N) among the N downlink subframes is assigned with a unique correlation label d according to a preset rule in order to represent that the subframe is positioned at a subframe position with a label of d during the mapping process, and 0 <d <N. The default rule can be any one-to-one mapping from a set i =

ES 2 643 597 T3 {0,1, ..., Λ / -1} to a set d = {0,1, ..., N -1}, for example, d = i, a correlation mode in the one that the special subframe is placed in the last position; or a correlation mode in which the subframe with the maximum real value of n is placed in the main position, especially, a correlation mode in a sequence from the maximum real value of n to the minimum real value of n. NccE.m represents the number of CCEs in the downlink subframe when the PCFICH value is m (0 <m <max {/ W /} -1), and is defined such that Ncceo = 0. The labels

M⁽¹'' f I ρτ jr ~ ru of the ACK channels assigned after the correlation process are represented by> and (Λ / χ Ncce.z) ACK channels reserved for the N downlink subframes are labeled 0 ~ N * Ncce .s-1, respectively.

In this embodiment, a BS schedules a certain UE in the subframe labeled d among the N downlink subframes, and assigns a label “cce (0 <riccE <Nccez'i to an initial CCE occupied by a PDCCH carrying a downlink scheduling assignment authorization command from the UE. w⁽¹⁾

Therefore, the BS assigns a channel label ACK pvccii _to| Initial CCE according to the following process: first, according to the value of «cce it is determined that a correlated ACK channel belongs to a subblock with a label of m in the subframe with the label of d, where the determination process includes selecting a value of m according to me {0,1,2} to satisfy Equation (1) NccE.m nccE NccEm + -¡ -1; and then the value of m «mifCH = OV ~ d - l) x N_cr.. + dx N,., .... + n_rcvobtained in the previous stage is substituted in Equation (2) ^PUCÍ-^{H v ctb} to calculate the assigned ACK channel label.

Equation (2) is described in detail below. When the channel corresponding to «cce is located in the sub-block with the label of m (0 <m <max {/ W /} -1, for example, m = 0, 1 or 2) in the subframe with the label of d , the first m sub-blocks (that is, sub-blocks with labels from 0 to (m-1)) of all the N sub-frames are placed in front of it, and the first m sub-blocks correspond to Λ / * NccE.m ACK channels; sub-blocks with the label m in the first d sub-frames, that is, sub-frames with labels from 0 to (d-1) among the N sub-frames are also placed in front of it, and the sub-blocks with the label m correspond to d χ (NccE , m + i -NccE.m) ACK channels; and finally, in the sub-block labeled m of the subframe labeled d, (ncce-NccE.m) ACK channels corresponding to the first (ncce-NccE.m) CCEs are also placed in front of it. Equation (2) is obtained by adding together the three previous elements.

The UE detects the PDCCH carrying the UE downlink scheduling authorization command in the subframe labeled d, and determines that the initial CCE label occupied by the „(h

PDCCH is occe (0 <nccE <Noce, 3) · The UE determines the pucch tag of the ACK channel assigned to the initial CCE according to the following process: first, according to the value of nccE it is determined that a correlated ACK channel belongs to a subblock with a label of m in the subframe with the label of d, where the determination process includes selecting a value of m according to me {0,1,2} to satisfy Equation (1) NccE.m nccE NccE, m + i -1; and then, the value of m obtained according to Equation (1) is substituted in Equation (2) ^{PICCI1 v 0X111} ccE, m + i ^CCE to calculate the assigned ACK channel label.

'PUCCH

The UE reports ACK / NAK information on the ACK channel with the tag of, and the BS detects the information ñ⁽¹⁾ .

of ACK / NAK reported on the ACK channel with the label of ^PUCCH . If the BS has scheduled the UE in a plurality of subframes out of the N subframes, the BS assigns a plurality of ACK channel labels to the UE according to the above correlation mode, and the UE generally uses the ACK channel corresponding to the initial CCE of the last PDCCH detected to report ACK / NAK information.

In the 3GPP E-UTRA system, L ACK channels are code division multiplexed in one RB and generally in a short cycle prefix subframe structure, L = 18. User data is scheduled from the RB only when the L code division multiplexed ACK channels on the RB are not available. Therefore, fit factors can also be entered in the sub-block division for fine-tuning, that is, CCE sets with labels of {0, 1, ..., A /_Cce, i-1-A1}, {/ V_Cce, i-A1, A /_Cce, i-A1 + 1, ..., Noce, 2-1-Δ2}, ..., {/ VccE, max {M /} - i-Amax {Mi} -1, A / ccE, max { M /} - i-Amax {Mi} -1 + 1, ..., A /_CcE, max {M /} -1} within the subframe correlate respectively with different subblocks. In this case, Δ1, Δ2, ..., Ámax {Mi} -1 are the adjustment factors, and their values ​​are determined in a sequence of Amax {Mi} -1, ..., Δ2, and Δ1, and , generally, they are not greater than 3. The introduction of the adjustment factors aims to form one or more complete RBs when the number of ACK channels of different CCE sets of the same subframe approaches an integral multiple of L. In the above descriptions, each subframe corresponds to a block in a preset sequence, where the preset sequence can be an original sequence of the N downlink subframes, a sequence that places the special subframe in the last position, a sequence that places the subframe with the maximum actual value of n in the main position (if a plurality of subframes has the same value n, the plurality of subframes can be placed

ES 2 643 597 T3 in the main positions according to a random sequence), or any other sequence that facilitates the release of more unused ACK channels as complete blocks.

An example in which each subframe corresponds to a block according to the original sequence of the N subframes is as shown in FIG. Four.

In the example shown in FIG. 4 ACK / NAKs of two downlink subframes in one uplink subframe need to be reported, and the Mi value for the two downlink subframes is 3. An actual value of n indicated by the PCFICH of the downlink subframe 0 is 3, and an actual value of n indicated by the PCFICH of downlink subframe 1 is 2. Each of the downlink subframes 0 and 1 occupies a block sequentially in the original sequence, that is, in the sequence in which subframe 0 precedes subframe 1. In subframes 0 and 1, the sub-blocks are further occupied sequentially according to the labels. As shown in FIG. 4 ACK channel resources can be released with labels in the range {(Ncce, 3⁺A / cce, 2) ~ (2A / cce, 3-1)}

In one example, each subframe corresponds to a block in a sequence in which the special subframe is placed last. Since n in the special subframe has a maximum value of 2 in the existing 3GPP system, more unused ACK channel resources can be released as full blocks if the special subframe is placed last.

An example where each subframe corresponds to a block in a sequence in which the subframe with the maximum actual value of n is placed in the leading position is as shown in FIG. 5.

In the example shown in FIG. 5 ACK / NAKs of downlink subframes 0 and 1 need to be reported in one uplink subframe, and the Mi value for the two downlink subframes is 3. An actual value of n indicated by the PCFICH of the subframe Downlink 0 is 2, and an actual value of n indicated by the PCFICH of downlink 1 subframe is 3. Since the value of n for the downlink subframe 1 is much larger, the downlink subframe 1 is placed in the main position. As shown in FIG. 5, ACK channel resources with labels in the range {(A / cce, 3⁺/ Vcce, 2) ~ (2 / Vcce, 3-1)} can be freed. If it is necessary to report the ACK / NAKs of more than two downlink subframes, each block may preferably be assigned to the subframes in a sequence from the maximum real value of n to the minimum real value of n for the subframes in order to clear plus unused ACK resources as full blocks.

In another embodiment, it is necessary to report the ACK / NAK of N downlink subframes in one uplink subframe, and the network side allocates ACK channels to the user according to the following rule.

In stage a, Ncce, my ACK channels are reserved for each downlink subframe, and a number is reserved

<img file="ES2643597T3_D0001.tif" />

total of '~^ο ACK channels.

Unlike stage 101, the stage reserves a different number of ACK channels for each downlink subframe according to their different Mi values, instead of reserving Ncce, max {M /} ACK channels for each subframe in order to reduce ACK channel resources reserved, saving system channel resources.

For example, when the Mi value for the special subframe is 2 and the Mi value for the other downlink subframes is 3, Ncce, 2 ACK channels are reserved for the special subframe, and Ncce, 3 channels are reserved for each of the other downlink subframes. Since they reserve Ncce, 2 ACK channels, instead of Ncce, 3 ACK channels, for the special subframe, the reserved ACK channel resources are reduced.

In step b, N subframes are mapped to the reserved ACK channels. Specifically, the reserved ACK channels are divided into N blocks, and each block is divided into My sub-blocks. Each subframe corresponds to a block in a predetermined sequence. Sub-blocks belonging to different blocks are arranged in an interlaced fashion. Sets of CCE with labels of {0, 1, ..., A / cce, i-1}, {Ncce.-i, Ncce.i + I, ·, (Ncce, 2- ^)}, .. ., {Ncce, me-i, NccE, M¡-t⁺ \, Ncce.mí- ^} within the same subframe are respectively correlated with different subblocks. For example, as for the special subframe with Mi of 2, the corresponding block is divided into 2 sub-blocks, and the sets of CCEs with labels of {0, 1, ..., A / cce, i-1}, {Ncce.-i, Ncce.i + V ·, (Ncce, 2-1)} within the subframe are respectively correlated with different subblocks. As for the subframes with Mi of 3, each block is divided into 3 sub-blocks, where the sub-blocks belonging to different blocks are arranged in an interlaced manner, and the sets of CCEs with labels of {0, 1, ..., A / cce.1-1}, {Ncce.-i, Ncce.i + I, ·, (Ncce, 2- ^)}, {Ncce, 2, (Ncce, 2 + 1), ·, (Ncce, 3-1)} within the same subframe are respectively correlated with different subblocks.

In 3GPP E-UTRA system, if there is a special subframe in the N subframes, the special subframe is preferably placed in the last position, that is, when the correlation label d is assigned to the subframe with the

ES 2 643 597 T3 label of i, the special subframe is always assigned with d = N-1. Therefore, in step b, the BS and UE n⁽¹⁾ determine an ACK 'pucch channel label correlated with a CCE with a label of «cce in the subframe with the label of d according to the following process: first, according to the value of« cce it is determined that a correlated ACK channel belongs to a subblock with a label of m in the subframe with the label of d, where the determination process includes selecting a value of m according to me {0,1,2} to satisfy Equation (1) Ncce ™ &lt;riccE NccE, m + t -1; and then, the value of m obtained in the previous stage is substituted in Equation (2) ^bpuccu ^_ l)^x- ^ ccE.m⁺^^Xj^ ccü, n &gt;&gt; i^{+ w}«Ep_{for ca}|_cu|_ar |_to ACK channel label assigned. It should be noted that since there are only 2 sub-blocks for the special subframe, m cannot take the value of 2 in the above determination process of Equation (1), although me {0,1,2}; alternatively, it can also be defined in the determination process of Equation (1) that me {0,1} for the special subframe.

Fit factors can also be entered into the sub-block division for fine tuning, that is, CCE sets with labels of {0, 1, ..., A / cce.i-1-ΔΙ}, {A / cce .i-ΔΙ, A /_Cce, i-A1 + 1, ..., A /_Cce, 2-1-Δ2}, ..., {Ncce, mi-iΔΜί-1, A / cce, m / -i-AMÍ-1 + 1, ..., Ncce.mi-1} within the subframe are respectively correlated with different subblocks. In this case, Δ1, Δ2, ..., and ΔΜί-1 are the adjustment factors, and their values ​​are determined in a sequence of ΔΜί-1, ..., Δ2, and Δ1, and typically are not greater than 3.

The preset sequence can be an original sequence of the N downlink subframes, a sequence that places the special subframe in the last position, or a sequence that places the subframe with the maximum actual value of n in the main position, where it can be done a specific reference to the above embodiment.

In another embodiment, it is necessary to report the ACK / NAK of N downlink subframes in one uplink subframe, and the network side allocates ACK channels to the user according to the following rule.

In step a, ACK channels are reserved for each downlink subframe. Ncce, me or Ncce, max {M /}

To the

Σ CCE, Mi ACK channels are reserved for each subframe, that is, a total number of N χ Ncce, max {M /} or ^¡= ° channels.

In step b, N subframes are mapped to the reserved ACK channels. Specifically, the ACK channels are consecutively correlated with each subframe. The N subframes can be arranged in a random sequence. An example is like that shown in FIG. 6. In this example, it is necessary to report the ACK / NAK of two downlink subframes in one uplink subframe, and the Mi value for the two downlink subframes is 3. An actual value of n indicated by the PCFICH of downlink subframe 0 is 2, and an actual value of n indicated by the PCFICH of downlink subframe 1 is 3. After subframe 0 is mapped to channels ACK, subframe 1 is mapped to the remaining ACK channels. Consecutive correlation mode can ensure that there are no unused ACK channels between the ACK channels that each subframe is mapped to, allowing more unused ACK channels to be released as full blocks. In the example shown in FIG. 6 ACK channel resources can be released with labels in the range {(Ncce, 3⁺Ncce, 2) ~ (2A / cce, 3-1)}

ACK channels released with labels in the range of {(Ncce, 3⁺Ncce, 2) ~ (2A / cce, 3-1)} can form one or more complete RBs for PUSCH transmission.

Table 1

<td rowspan="3">System bandwidth</td><td colspan="6">CCE number</td>

<td colspan="2">n = 1</td><td>n =</td><td> 2</td><td colspan="2">n = 3</td>

<td>1 or 2 transmitting antennas</td><td>4 transmitting antennas</td><td>1 or 2 transmitting antennas</td><td>4 transmitting antennas</td><td>1 or 2 transmitting antennas</td><td>4 transmitting antennas</td>

<td>1.25 MHz</td><td> 0</td><td> 0</td><td> 2</td><td> 1</td><td> 4</td><td> 3</td>

<td>5 MHz</td><td> 3</td><td> 3</td><td> 12</td><td> 9</td><td> 20</td><td> 17</td>

<td>10 MHz</td><td> 8</td><td> 8</td><td> 25</td><td> 19</td><td> 41</td><td> 36</td>

<td>20 MHz</td><td> 17</td><td> 17</td><td> 50</td><td> 39</td><td> 84</td><td> 73</td>

As shown in Table 1, in the situation where the system bandwidth is 20 MHz and 4 antennas are configured, and n takes the values ​​1, 2 and 3, Λ / cce, 1 = 17, Λ / cce, 2 = 39 and Ncce, 3 = 73. Tagged ACK channels can be released in the range 112-145, ie 34 ACK channels can be released. If an RB can only multiplex 18 ACK channels, at least one RB can be released for PUSCH transmission.

ES 2 643 597 T3

In the example above, 34 ACK channels can be released. However, since L is set to 18, the remaining 16 ACK channels that are released cannot form a complete RB for PUSCH transmission. In this case a fine adjustment can be made to correlate the set of CCEs that has the label of {/ Vcce, 2-A2, Ncce, 2-Δ2 + 1,, Ncce, 3-1} with the last sub-block and, in this case, Δ2 takes the value 2. In this way a total number of 36 ACK channels can be released, which can form 2 complete RBs for PUSCH transmission.

Another example shows how to determine the values ​​of Δ1 and Δ2 during fine tuning. As shown in Table 1, in the situation where the system bandwidth is 10 MHz and 1 or 2 antennas are configured, and n takes the values ​​1, 2 and 3, Ncce, 1 = 8, Ncce, 2 = 25 and Ncce, 3 = 41. Since 16 (= 41-25) and 17 (= 25-8) approximate L (= 18), first set the value of Δ2 to 2, and then set the value of Δ1 to 3, so that {Ncce, 2-E2, Ncce2-E2 + '\, ..., Ncce, 3-1} and {A / cce.i-ΔΙ, A / cce, i-A1 + 1, ..., Ncce, 2 -1-Δ2} can form complete RBs.

In the above embodiments there is a one-to-one correlation relationship between the CCEs of the subframes and the ACK channels, and the sets of ACK channels that do not overlap each other are reserved for each subframe. When it is necessary to reserve ACK channel resources for the notifications of N downlink subframes in one uplink subframe, a large number of resources can be reserved, especially when N takes on a large value. For example, regarding the 3GPP E-UTRA system, when a downlink to uplink ratio is 9: 1, and N = 9, one ACK channel is reserved for each CEE in each subframe, resulting in resulted in a large overhead.

The following procedures can be used to troubleshoot the high overhead of reserved ACK channel resources.

In procedure 1, a plurality of downlink subframes are mapped to the same set of ACK channels, and the one-to-one mapping of CCE labels to ACK channel labels is still used in the subframes. That is, a plurality of downlink subframes are assigned with the same correlation label d in the correlation process. As regards downlink subframes with the same correlation label d, the number of reserved ACK channels is not less than a maximum number of CCEs of any one of the downlink subframes. In the 3GPP E-UTRA system, this means that if the special subframe and the usual downlink subframes are assigned with the same correlation label d, there are Ncce.z ACK channels in their corresponding ACK channel set.

The BS may notify the user about the assignment of the correlation label via high-level signaling, for example by broadcasting.

The BS and the UE determine a channel label ACK pucc.h correlated to a CCE with a label of nccE in the subframe with the label of d according to the following process: first, according to the value of nccE it is determined that a channel Correlated ACK belongs to a subblock with a label of m in the subframe with the label of d; for example, in the 3GPP E-UTRA system, the determination process includes selecting a value of m according to me {0,1,2} to satisfy Equation (1) Ncce ™ hcce NccE, m + t -1; and then, the value of m obtained in the previous stage is substituted in Equation (2)^Kpuccn 9^x^ ccc, m + ^^x^ ccE, m + i ^{+ w}cce p_{for ca}|_cu|_ar |_to ACK channel label assigned.

In procedure 2, non-overlapping ACK channel sets are reserved for each downlink subframe, but the one-to-one mapping of the CCE labels to ACK channel labels is not used in the subframes and instead , a plurality of CCEs can be assigned with the same ACK channel. A commonly used procedure is to reserve one ACK channel for each K CCE with consecutive labels. The specific stages are listed below.

XlNTEGER (N_{CC £ My}/ K)

N x INTEGER (NccE, max {Mi} / K) or ¡-o reserved channels for N downlink subframes are divided into N blocks, and each block contains INTEGER (NccE, max {Mi} / K) or INTEGER {Ncce , m¡ / K) channels. Each downlink subframe is assigned with a correlation label d according to a predetermined rule, and each correlation label corresponds to a block. INTEGERQ represents a round operation, and can be a round-up operation_Γ η or a round-down operation ^LJ . It can be seen that when K is greater than 1, the number of ACK channels to be reserved is reduced to 1 / K of the number of CCEs, so that K can also be called ACK resource reduction factor.

When a total number of N χ INTEGER (NccE, max {Mi} / K) are reserved, that is, INTEGER (NccE, max {Mi} / K) ACK channels are reserved for each downlink subframe, each block is divided in max {/ W /} subblocks, and a subblock with a label of m contains INTEGER (NccE, m + i / K) - INTEGER (NccErrJK ') channels

ES 2 643 597 T3 ^ INTEGER (N_ccem/ K)

ACK, where 0 &lt;m &lt;max {/ W /}. When a total number of '⁰ channels are reserved, that is, INTEGER (Ncce, me / K) ACK channels are reserved for each downlink subframe, each block is divided into My sub-blocks, and a sub-block with a label of m contains INTEGER (NccE, m + t / K) INTEGER (NccErrJK ') ACK channels, where 0 &lt;m &lt;Me.

All ACK channels are mapped to the sub-blocks and arranged first according to an increasing sequence of correlation labels d and then according to an increasing sequence of sub-block labels m. In the 3GPP E-UTRA system, a PDCCH can be formed by 1, 2, 4 or 8 CCE, so it is recommended that K take values ​​in non-empty subsets of a set {1, 2, 4, 8}, and the specific value of K is reported by the BS to the user through high-level signaling.

The BS and the UE determine an ACK pucch channel label correlated with a CCE with an nccE label in the subframe with the label d according to the following process: first, based on the value of nccE it is determined that a correlated ACK channel belongs to a subblock labeled m in the subframe labeled d; For example, in the 3GPP E-UTRA system, the determination process includes selecting a value of m according to me {0,1,2} to satisfy Equation (3) INTEGER (NccE, rr / K) * K &lt;nccE INTEGER (NccE, m + i / K) χ K-1; and then, the value of m obtained in the previous stage is substituted in the Equation = (Nd -]) * ¡NTEGER (N. ^_youJK) + &lt;lxlNTEGER (l '&lt;'_{í (: l}._ln._l! K) +_{for ca | cu | ar | a etjque (a} ACK channel assigned. When K = 1, Equations (3) and (4) simplify to become, respectively, Equations (1) and (2).

(4) of the

In procedure 2, a mode of mapping a plurality of CCEs to the same ACK channel is used for some subframes, and a mode of mapping each CCE to a different ACK channel (i.e., the one-to-one mapping mode of the CCE labels with ACK channel labels) is used for the other subframes.

In procedure 2, when INTEGERQ specifically represents the round-down operation ^LJ , several CCEs remaining after K is rounded down in the subframes may not have any corresponding ACK channels. For example, when Ln_ccemí/ k-1 ACK channels are reserved for the subframe with the label of i, if Ncce, me cannot be exactly divided by K, only CCEs with labels of 0 ~ ^ -NccemJK- ^ * / &lt;- 1 can be mapped to the ACK channels, and the other CCEs labeled ^ -NccemJK- ^ ^xK ~ Ncce, m¡- ^ cannot be correlated with ACK channels according to Equations (3) and (4). Therefore, on the BS side, the CCEs with the labels ^ -NccemJK- ^ * K ~ Ncce, me-1 are not assigned as the initial CCEs occupied by a PDCCH carrying a scheduling assignment authorization command downlink.

In method 1 certain limitations can be introduced to avoid a collision between ACK channels for a plurality of downlink subframes assigned with the same correlation label d. For example, it is limited that among the CCEs with the same label in the plurality of downlink subframes assigned with the same correlation label d, at least one CCE is taken as the initial CCE occupied by the PDCCH carrying the authorization command. downlink scheduling assignment.

In procedure 2 certain limitations can also be introduced to avoid a collision between ACK channels in the subframes after the correlation process. For example, it is limited that between every K CCE with consecutive labels, at least one CCE is taken as the initial CCE occupied by the PDCCH carrying the downlink planning assignment authorization command. A simple implementation procedure is to limit the initial CCE labels occupied by all PDCCHs carrying the downlink scheduling allowance command to be multiples of K.

The effects of the correlation process using Equations (3) and (4) are illustrated below by specific examples. Since Equations (1) and (2) are special cases of Equations (3) and (4) when K = 1, no particular example is provided for Equations (1) and (2).

As shown in Table 1, in the situation where the system bandwidth is 20 MHz and 2 antennas are configured, and n takes the values ​​of 1, 2 and 3, / \ / cce, i = 17, Ncce, 2 = 50 and Ncce, 3 = 84. In this example, the number of downlink subframes to be reported by ACKs in an uplink subframe is 3, that is, N = 3, and all three subframes are typical subframes. Therefore, the ACK channel labels correlated with the CCE labels of each subframe using Equations (3) and (4) are shown respectively in Tables 2, 3, 4 and 5 when K = 1, 2, 4 and 8 , and INTEGERQ specifically represents the round-up operation _Γη.

ES 2 643 597 T3

Table 2 K = 1, N = 3, Ncce, i = 17, Ncce, 2 = 50, Ncce, 3 = 84

<td>Subplot d</td><td>CCE label in subframe</td><td>Channel label ACK</td>

<td rowspan="3">d = 0</td><td> 0—16</td><td> 0-16</td>

<td> 17-49</td><td> 51-83</td>

<td> 50—83</td><td> 150-183</td>

<td rowspan="3">d = 1</td><td> 0-16</td><td> 17-33</td>

<td> 17-49</td><td> 84-116</td>

<td> 50-83</td><td> 184-217</td>

<td rowspan="3">d = 2</td><td> 0-16</td><td> 34-50</td>

<td> 17-49</td><td> 117-149</td>

<td> 50-83</td><td> 218-251</td>

Table 3 K = 2, N = 3, Ncce, i = 17, Ncce, 2 = 50, Ncce, 3 = 84

<td>Subplot d</td><td>CCE label in subframe</td><td>Channel label ACK</td>

<td rowspan="3">d = 0</td><td> 0-17</td><td> 0-8</td>

<td> 18-49</td><td> 27-42</td>

<td> 50-83</td><td> 75-91</td>

<td rowspan="3">d = 1</td><td> 0-17</td><td> 9-17</td>

<td> 18-49</td><td> 43-58</td>

<td> 50-83</td><td> 92-108</td>

<td rowspan="3">d = 2</td><td> 0-17</td><td> 18-26</td>

<td> 18-49</td><td> 59-74</td>

<td> 50-83</td><td> 109-125</td>

Table 4 K = 4, N = 3, Ncce, i = 17, Ncce, 2 = 50, Ncce, 3 = 84

<td>Subplot d</td><td>CCE label in subframe</td><td>Channel label ACK</td>

<td rowspan="3">d = 0</td><td> 0-19</td><td> 0-4</td>

<td> 20-51</td><td> 15-22</td>

<td> 52-83</td><td> 39-46</td>

<td rowspan="3">d = 1</td><td> 0-19</td><td> 5-9</td>

<td> 20-51</td><td> 23-30</td>

<td> 52-83</td><td> 47-54</td>

<td rowspan="3">d = 2</td><td> 0-19</td><td> 10-14</td>

<td> 20-51</td><td> 31-38</td>

<td> 52-83</td><td> 55-62</td>

Table 5 K = 8, N = 3, Ncce, i = 17, Ncce, 2 = 50, Ncce, 3 = 84

<td>Subplot d</td><td>CCE label in subframe</td><td>Channel label ACK</td>

<td rowspan="3">d = 0</td><td> 0-23</td><td> 0-2</td>

<td> 24-55</td><td> 9-12</td>

<td> 56-83</td><td> 21-24</td>

<td rowspan="2">d = 1</td><td> 0-23</td><td> 3-5</td>

<td> 24-55</td><td> 13-16</td>

<td></td><td> 56-83</td><td> 25-28</td>

<td>d = 2</td><td> 0-23</td><td> 6-8</td>

ES 2 643 597 T3

<td>Subplot d</td><td>CCE label in subframe</td><td>Channel label ACK</td>

<td rowspan="2"></td><td> 24-55</td><td> 17-20</td>

<td> 56-83</td><td> 29-32</td>

As seen from the data in Tables 2 to 5, the higher the value of K, the fewer ACK channels have to be allocated, so that the overhead on ACK channel resources is reduced.

Those skilled in the art should understand that all or part of the steps of the above embodiments can be implemented by relevant hardware under the instructions of a program, and the program can be stored on a computer-readable storage medium, such as a memory. read-only (ROM) or random access memory (RAM), magnetic disk, or optical disk.

It should be understood that although the steps of the procedures are described sequentially in the foregoing descriptions for ease of understanding, the sequence of the foregoing steps is not strictly limited.

In one embodiment, a device 701 for assigning ACK channels to a user is as shown in FIG. 7. Device 701 includes reservation unit 702 and allocation unit 703. Reservation unit 702 is configured to reserve channels for each downlink subframe (including special subframe), eg INTEGER (NccE, max { Mi} / K) or INTEGER (NccemJK) ACK channels are reserved for ^ INTEGER (N_ccemi/ K) each subframe, ie a total number of N * INTEGER (NccE, max {Mi} / K) or channels is reserved. The allocation unit 703 is configured to allocate the reserved ACK channels to the N downlink subframes. Specifically, the allocation unit 703 divides the reserved ACK channels into N blocks; assigns each downlink subframe with a correlation label d according to a predetermined rule, where each correlation label corresponds to a block; divide each block into a plurality of subblocks; and allocates the ACK channels to each downlink subframe, first according to an increasing sequence of correlation labels d and then according to an increasing sequence of subblock labels m. The default rule can be a correlation mode in which the special subframe is placed in the last position, or a correlation mode in which the subframe with the maximum real value of n is placed in the main position, especially a mode of correlation in a sequence from the maximum real value of n to the minimum real value of n for the subframes.

During the process of dividing each block into a plurality of sub-blocks, when INTEGER (NccE, max {Mi} / K) channels are reserved for each sub-frame, each block is divided into max {/ W /} sub-blocks, and a sub-block with a m label contains INTEGER (Ncce ~ + -¡ / K ') - INTEGERí, Ncce ~ JK) channels; and when INTEGER (Ncce, m, / K) channels are reserved for each subframe, each block is divided into My sub-blocks, and a sub-block with a label of m contains INTEGER (NccE, m + i / K) - INTEGER (NccEm / K) channels.

An allocation mode can be as follows.

ACK channels are assigned to downlink subframes in a correlation mode of consecutive K CCEs to one ACK channel; alternatively, the ACK channels are assigned to the downlink subframes by mapping a plurality of downlink subframes to the same set of ACK channels.

Alternatively, when each block is divided into max {/ W /} subblocks, the sets of CCEs with labels of {0, 1,, A / cce, i-1-A1}, {NccE.t-ΕΊ, A / cce, i-A1 + 1, ..., Ncce, 2-1-Δ2}, ..., {Λ / οοε, μ / -ι-ΔΜΙ-1, Λ / οοε, μ / -ι-ΔΜΙ- 1 + 1, ..., Ncce.mí- ^} within the same subframe are respectively correlated with different subblocks; when each block is divided into My subblocks, the CCE sets with labels of {0, 1, ..., A / cce, i-1-A1}, {/ Vcce, i-A1, A / cce, i-A1 + 1, ..., Ncce, 2-1-Δ2, ..., {Λ / cce, m / -i-AM¡-1 Á / cce, m / -i-AM¡-1 + 1,. .., Ncce, mi-T} within the same subframe are respectively correlated with different subblocks.

In another embodiment, reservation unit 702 is configured to reserve Ncce, max {M /}, or Ncce, mi ACK channels for each downlink subframe, and allocation unit 703 is configured to allocate ACK channels to downlink subframes consecutively correlating ACK channels with each subframe among the reserved ACK channels.

In one embodiment, a communication system 801 is provided, as shown in FIG. 8. The communication system 801 includes a device 802 for assigning ACK channels to a user and a UE 803. The device 802 further includes a reservation unit and an allocation unit that have, respectively, the same functions as the reservation unit. 802 and allocation unit 803. Device 802 is located on a network side, for example in a BS on the network side. Since the UE has already acquired a rule

ES 2 643 597 T3 to assign ACK channels in advance, the UE directly reports ACK information of N downlink subframes to the network side by the assigned ACK channels.

It should be understood that the devices or units of the accompanying drawings (or of the embodiments) are merely examples and represent logical structures, among which the units shown as independent components may or may not be physically separated, and the components shown as Drives may or may not be physical drives, that is, they may be located in one location or distributed across a plurality of network drives.

The accompanying drawings and relevant descriptions are only intended to illustrate the principles of the present invention and do not limit the scope of the present invention. For example, although the embodiments are described on the basis of the 3GPP TDD system, the technical solution of the present invention can also be applied in other networks or systems, for example in half-duplex FDD systems (HD-FDD), provided that requires reporting the ACK / NAKs of a plurality of downlink subframes in one uplink subframe. Therefore, any modification, equivalent variation or improvement made without departing from the principle of the present invention will be within the scope of the present invention.