CN101616491A - Method for mapping uplink ACK/NACK channel - Google Patents

Abstract

The present invention proposes the method for a kind of mapping CCE to ACK/NACK, comprise step: subscriber equipment detects downlink physical control channel, and downlink data receiving; Subscriber equipment is according to the CCE in each subframe being carried out whether comprise the ACK/NACK channel that DwPTS obtains described CCE correspondence in sub-frame of uplink in the boundary value of piecemeal, the current binding window; Subscriber equipment sends described ack/nack signal.

Description

Method for mapping uplink ACK/NACK channel

technical field

The present invention relates to a wireless communication system, more specifically to a method for allocating uplink ACK/NACK channels for downlink data transmission in the wireless communication system.

Background technique

The 3GPP standardization organization is conducting long-term evolution (LTE) of its existing system specifications. Fig. 2 is the frame structure of the LTE TDD system. Each radio frame with a length of 307200×T _s =10 ms is equally divided into two half frames with a length of 153600×T _s =5 ms. Each half-frame contains 8 time slots with a length of 15360T _s =0.5ms and 3 special domains, namely downlink pilot time slot (DwPTS), guard interval (GP) and uplink pilot time slot (UpPTS). The sum of the lengths of the special domains is 30720T _s =1 ms. Each subframe consists of two consecutive time slots, that is, the kth subframe includes time slot 2k and time slot 2k+1. Subframe 1 and subframe 6 include the above three special fields.

According to the current discussion results of LTE, the downlink control channel is transmitted in the first n OFDM symbols of each downlink subframe. The physical control format indicator channel (PCFICH) is used to transmit the value of n above, so that the physical downlink control channel (PDCCH) is transmitted in the first n OFDM symbols. When the system bandwidth is large, n is equal to 1, 2 or 3 for general downlink subframes; n is equal to 1 or 2 for DwPTS. When the system bandwidth is small, n is equal to 2, 3 or 4 for general downlink subframes; for DwPTS, it is not yet defined whether n is equal to 1 or 2, or n can only be equal to 2. Here, PCFICH is transmitted in the first OFDM symbol of each subframe, and PDCCH is obtained by combining one or more control channel elements (CCE). Each CCE contains a fixed number of subcarriers. According to the current results, the number of CCEs included in the PDCCH can be 1, 2, 4 and 8.

According to the current discussion results of LTE, physical time-frequency resources are divided into multiple resource blocks (RB), and RB is the minimum granularity of resource allocation. Each resource block includes M consecutive subcarriers in the frequency domain and N consecutive symbols in time, which are OFDM symbols for downlink and SCFDMA symbols for uplink.

According to the current discussion results of hybrid automatic repeat request (HARQ) based transmission of downlink data in LTE, for dynamic scheduling, the index of the ACK/NACK channel is implicitly bound to the minimum index of the CCEs that make up the PDCCH. The number of actually available CCEs in each downlink subframe is also dynamically configured with the PCFICH, and only the CCEs that are dynamically scheduled for downlink data transmission need to be actually bound to the uplink ACK/NACK channel, which results in the actual number of ACK/NACKs required is dynamic. However, the number of ACK/NACK channels in the uplink direction is configured semi-statically, which leads to the fact that only a part of ACK/NACK channels are occupied under normal circumstances. When all ACK/NACK channels in one or more RBs semi-statically configured for transmitting ACK/NACK information are not occupied, in order to fully utilize system resources, these RBs may be allocated for dynamic scheduling of uplink data.

In the LTE TDD system, when binding ACK/NACK channels for data transmission in each downlink subframe, it may be necessary to map the CCEs of multiple downlink subframes to the ACK/NACK channel of the same uplink subframe. The present invention proposes a method for mapping CCEs to ACK/NACKs, which can minimize the number of required ACK/NACK channels, thereby saving more RBs of control channels, which can be used for dynamic scheduling of uplink data.

Contents of the invention

The purpose of the present invention is to provide a method for allocating uplink ACK/NACK channels for downlink data transmission in a wireless communication system.

In order to achieve the above object, a method for mapping CCE to ACK/NACK comprises steps:

a) The user equipment detects the downlink physical control channel and receives downlink data;

b) The user equipment obtains the ACK/NACK channel corresponding to the CCE in the uplink subframe according to the boundary value for dividing the CCE in each subframe and whether the current binding window contains DwPTS;

c) The user equipment sends the ACK/NACK signal.

Description of drawings

Figure 1 is the frame structure of LTE TDD;

FIG. 2 is a schematic diagram 1 of block-interleaved mapping ACK/NACK channels;

FIG. 3 is a schematic diagram 2 of mapping ACK/NACK channels by block interleaving.

Detailed ways

For a TDD system, in some frame structures with uplink and downlink configuration ratios, ACK/NACK channels corresponding to multiple downlink subframes need to be transmitted in the same uplink subframe. Here, multiple downlink subframes corresponding to ACK/NACK channels transmitted in the same uplink subframe are defined as bundling windows. Note that the number of downlink subframes in the binding window is D.

Firstly, define a unique set of boundary values {N _k , k=0, 1, 2, ..., k _max } for CCE blocks in the binding window, where N ₀ is fixed equal to 0, so that by CCE Divide the CCEs in each downlink subframe into k _max CCE blocks with the index of k=0, 1, 2, . . . , k _max -1. The k=0 th CCE block includes CCEs with indexes from 0 to N ₁ -1; the k=1 th CCE block includes CCEs with indexes from N ₁ to N ₂ -1, and so on. Here, the number of CCE blocks k _max may be equal to the number of possible values of the number of OFDM symbols used for control channels in a common downlink subframe within the bundling window. In addition, the number of CCEs in the downlink subframe is determined by the number of OFDM symbols used for the control channel in the current subframe and whether the current subframe contains PHICH, and the number of CCEs in the downlink subframe containing PHICH is less than or equal to not containing PHICH The number of CCEs in the downlink subframe of . In this way, the possible values of the number of OFDM symbols used for the control channel in the downlink subframe are indexed in order of arrival from small to k=0, 1, 2, ..., k _max -1, and the boundary value N _k can be It is set to be the maximum value of the number of CCEs of each downlink subframe in the bundling window when the number of OFDM symbols used for the control channel in the downlink subframe takes the k-1th value.

Next, it can be processed separately according to whether the binding window contains DwPTS.

When the binding window does not contain the DwPTS, all downlink subframes in the binding window are indexed, and the index is d=0, 1, 2, . . . D-1. Here, one indexing method is to index according to the time order of the subframes in the binding window; another indexing method is to assign a larger index to the downlink subframes containing PHICH, for example, when the binding window contains When a downlink subframe includes PHICH, its index is D-1. Then, the CCE blocks of each downlink subframe are interleaved, and the ACK/NACK channel indexes to which they are mapped are sequentially calculated. Specifically, firstly, the ACK/NACK channel is mapped to the k=0th CCE block of each subframe in the bundling window in sequence according to the index order of the subframe, that is, the k=0th CCE block of the d=0th subframe is first The CCEs in the CCE block map the ACK/NACK channel; then map the ACK/NACK channel for the CCEs in the k=0th CCE block of the d=1th subframe; and so on until the completion of the d=D-1th subframe The CCEs in the k=0th CCE block of the frame are mapped to ACK/NACK channels. Then, map the ACK/NACK channel for the k=1th CCE block of each subframe in the binding window in sequence according to the index order of the subframe, and so on, until each The k=k _max -1th CCE block of the subframe is mapped to the ACK/NACK channel.

When the binding window contains DwPTS, because the number of possible values of the number of OFDM symbols used for the control channel in the DwPTS is smaller than that of the general downlink subframe, it is recorded as k _max ^DwPTS , namely $k_{\max }^{\mathrm{wxya}}<k_{\max }.$ The possible values of the number of OFDM symbols used for the control channel in a general subframe are indexed in order of arrival from small to k=0, 1, 2, ..., k _max -1, then in DwPTS, for The index of the number of OFDM symbols of the control channel is $k=\mathrm{0,1,2},...,k_{\max }^{\mathrm{wxya}}-1.$ Here, generally the downlink subframe is divided into k _max CCE blocks, but there are only k _max ^DwPTS CCE blocks in the DwPTS. In this way, the index of the CCE block to which the CCE of a downlink subframe belongs is recorded as k, for $k<k_{\max }^{\mathrm{wxya}}$ and $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ In the two cases of , the ACK/NACK channel is mapped to the CCE block respectively.

First, the index of each downlink subframe in the binding window $k<k_{\max }^{\mathrm{wxya}}$ The CCE block maps the ACKNACK channel. At this time, all downlink subframes in the binding window are indexed, and the index is d=0, 1, 2, ... D-1; here, a method of indexing is to press the subframe in the binding window Indexing in chronological order; another indexing method is to assign a larger index to the downlink subframe containing PHICH, for example, when the binding window contains a downlink subframe containing PHICH, its index is D-1; Then, the CCE blocks of each downlink subframe are interleaved, and the ACK/NACK channel indexes to which they are mapped are sequentially calculated. Specifically, firstly, the subframes map the ACK/NACK channel for the k=0th CCE block of each subframe in the bonding window in sequence according to the index order of the subframes; The k=1th CCE block of each subframe in each subframe is mapped to the ACK/NACK channel; and so on until the index order of the subframe is the first $k=k_{\max }^{\mathrm{wxya}}-1$ CCE blocks are mapped to ACK/NACK channels.

Then, for the index of each downlink subframe in the binding window $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ The CCE block maps the ACKNACK channel. Index all downlink subframes in the binding window except DwPTS, and record the index as d=0, 1, 2, ... D-2; here, a method of indexing is to press the binding window except The time sequence of subframes other than DwPTS is indexed; another indexing method is to assign a larger index to the downlink subframe containing PHICH, for example, when the binding window contains a downlink subframe containing PHICH, its index is D-2; then, starting from the end position of the first k _max ^DwPTS CCE blocks mapping ACK/NACK, interleave the CCE blocks of each downlink subframe except DwPTS, and calculate the ACK/NACK channels to be mapped to in turn index. Specifically, firstly, according to the index order of the subframes, the subframes in the binding window except DwPTS $k=k_{\max }^{\mathrm{wxya}}$ CCE blocks map the ACK/NACK channel; then, according to the index order of the subframes, the order of each subframe in the binding window except DwPTS $k=k_{\max }^{\mathrm{wxya}}+1$ Each CCE block is mapped to the ACK/NACK channel; and so on until the index order of the subframe is used to map the ACK/NACK channel to the k=k _max -1th CCE block of each subframe in the binding window except DwPTS.

Based on the above method of mapping CCEs to ACK/NACK in blocks, the following describes the first method of determining the mapped ACK/NACK channel according to the CCE index. For a CCE whose index is n _CCE in a downlink subframe in the binding window, first determine the CCE block where this CCE is located, and remember that it belongs to the kth CCE block, that is, satisfy N _k <n _CCE <N _k+1 . Then determine its mapped ACK/NACK channel. For the LTE TDD system, when indexing the downlink subframes in the binding window, according to the current definition of HARQ timing, if there is a subframe containing PHICH in a binding window, then this subframe must be located in the binding window , so the downlink subframes in the binding window can be indexed in time order; similarly, when indexing the downlink subframes in the binding window except DwPTS, you can index the downlink subframes in the binding window except DwPTS The downlink subframes of are indexed in time order.

When the DwPTS is not included in the binding window, all downlink subframes in the binding window are indexed, recorded as d=0, 1, 2, . . . D-1. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=(\mathrm{D.}-d-1)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter.

When the binding window contains DwPTS, the $k<k_{\max }^{\mathrm{wxya}}$ and $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ In the two cases of , the ACK/NACK channel is mapped to the CCE respectively.

when $k<k_{\max }^{\mathrm{wxya}}$ When , all downlink subframes in the binding window are indexed, which is recorded as d=0, 1, 2, . . . D-1. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=(\mathrm{D.}-d-1)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter.

when $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ When , all downlink subframes in the binding window except DwPTS are indexed, which is recorded as d=0, 1, 2, ... D-2. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=N_{k_{\max }^{\mathrm{wxya}}}+(\mathrm{D.}-d-2)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter, N _{CCE, and max} ^DwPTS is the maximum number of CCEs included in the DwPTS.

For the TDD system, because the ACK/NACK of multiple downlink subframes needs to be transmitted in the same uplink subframe, the overhead of the ACK/NACK channel in this uplink subframe is relatively large. The following is based on block mapping CCE to ACK The /NACK method describes a method for reducing the overhead of the ACK/NACK channel in the uplink subframe. Here, for every m consecutive CCEs in the downlink subframe, only the first CCE is mapped to the ACK/NACK channel; or, every m consecutive CCEs in the downlink subframe can be mapped to the same ACK/NACK channel. Here, the PDCCH used for downlink scheduling may be restricted to only occupy several CCEs starting from the CCE with the smallest index among the m CCEs. As for the PDCCH used for uplink scheduling, like the PDCCH used for uplink scheduling, it can be restricted to occupy only a few CCEs starting from the CCE with the smallest index among the m CCEs; or, there is no restriction. For example, taking the LTE system as an example, the values of m can be configured to be 1, 2, 4, and 8.

Based on the above method of mapping CCEs to ACK/NACK in blocks, the following describes the second method of determining the mapped ACK/NACK channel according to the CCE index. For a CCE whose index is n _CCE in a downlink subframe in the binding window, first determine the CCE block where this CCE is located, and remember that it belongs to the kth CCE block, that is, satisfy N _k <n _CCE <N _k+1 . Then determine its mapped ACK/NACK channel. Same as the first method, when indexing the downlink subframes in the binding window, the downlink subframes in the binding window can be indexed in time order; when indexing the downlink subframes in the binding window except DwPTS When indexing, the downlink subframes in the binding window other than the DwPTS may be indexed in time order.

When the DwPTS is not included in the binding window, all downlink subframes in the binding window are indexed, recorded as d=0, 1, 2, . . . D-1. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

这里，N_PUCCH ⁽¹⁾可以是半静态配置的参数。

Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter.

When the binding window contains DwPTS, the $k<k_{\max }^{\mathrm{wxya}}$ and $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ In the two cases of , the ACK/NACK channel is mapped to the CCE respectively.

when $k<k_{\max }^{\mathrm{wxya}}$ When , all downlink subframes in the binding window are indexed, which is recorded as d=0, 1, 2, . . . D-1. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

这里，N_PUCCH ⁽¹⁾可以是半静态配置的参数。

Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter.

when $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ When , all downlink subframes in the binding window except DwPTS are indexed, which is recorded as d=0, 1, 2, ... D-2. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

Here, N _PUCCH ⁽¹⁾ may be a semi-statically configured parameter, N _{CCE, and max} ^DwPTS is the maximum number of CCEs included in the DwPTS.

In order to simplify the formula for CCE mapping ACK/NACK, the following method for indexing subframes can be used. Note that the number of subframes in the binding window is D. When DwPTS is included in the binding window, the largest index D-1 is fixed for DwPTS, and the indexes of other subframes are d=0, 1, 2, ... D -1. Here, subframes other than DwPTS can be directly indexed in time order; in addition, when a subframe other than DwPTS contains PHICH, the second largest index D-2 can also be assigned to this subframe containing PHICH, and for The remaining subframes are indexed in time order as d=0, 1, 2, . . . D-3. When the binding window does not contain DwPTS, here, each subframe can be directly indexed in time order d=0, 1, 2, ... D-1; in addition, when a subframe contains PHICH, it can also be The subframe containing the PHICH is assigned the largest index D-1, and the remaining subframes are indexed in time order as d=0, 1, 2, . . . D-2.

Next, the CCE blocks of each downlink subframe are interleaved, and the ACK/NACK channel indexes to which they are mapped are sequentially calculated. Specifically, firstly, the ACK/NACK channel is mapped to the k=0th CCE block of each subframe in the bundling window in sequence according to the index order of the subframe, that is, the k=0th CCE block of the d=0th subframe is first The CCEs in the CCE block map the ACK/NACK channel; then map the ACK/NACK channel for the CCEs in the k=0th CCE block of the d=1th subframe; and so on until the completion of the d=D-1th subframe The CCEs in the k=0th CCE block of the frame are mapped to ACK/NACK channels. Then, map the ACK/NACK channel for the k=1th CCE block of each subframe in the binding window in sequence according to the index order of the subframe, and so on, until each The k=k _max -1th CCE block of the subframe is mapped to the ACK/NACK channel.

Based on this method of mapping CCEs to ACK/NACKs in blocks, for a CCE whose index is n _CCE in a downlink subframe in the binding window, first determine the CCE block where this CCE is located, and remember that it belongs to the kth CCE block, that is N _k <n _CCE <N _k+1 is satisfied. The downlink subframes in the binding window are indexed as d=0, 1, 2, . . . D-1. Here, when DwPTS is included, the index of DwPTS is D-1. In this way, for the CCE whose index is n _CCE in the dth downlink subframe, the index n _PUCCH ⁽¹⁾ of the ACKNACK channel mapped by it can be calculated by the following formula:

${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=(\mathrm{D.}-d-1)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ When considering reducing the overhead of the ACK/NACK channel, it can be calculated by the following formula:

这里，N_PUCCH ⁽¹⁾可以是半静态配置的参数，m是降低ACK/NACK开销的参数。

Here, N _PUCCH ⁽¹⁾ may be a parameter for semi-static configuration, and m is a parameter for reducing ACK/NACK overhead.

Example

This section presents two embodiments of the invention. In order to avoid making the description of this patent too lengthy, in the following description, detailed descriptions of functions or devices that are well known to the public are omitted.

Embodiment one:

This embodiment takes the LTE TDD system as an example to describe a method for mapping CCEs to ACK/NACKs by block interleaving when the system bandwidth is relatively large. For a larger bandwidth, the number of OFDM symbols used for the control channel in a general subframe can be 1, 2 or 3, while the number of OFDM symbols used for the control channel in DwPTS can only be 1 or 2. That is, k _max is equal to 3 and k _max ^DwPTS is equal to 2. Define a set of boundary values {N ₀ , N ₁ , N ₂ , N ₃ }, so that the CCEs in each downlink subframe are divided into blocks according to their index order. Here, N ₀ is equal to 0, N ₁ is the maximum number of CCEs in each downlink subframe in the bundling window when the number of OFDM symbols used for the control channel is equal to 1; N ₂ is the maximum number of CCEs used for the control channel When the number _of OFDM symbols is equal to 2, the maximum number of CCEs in each downlink subframe in the bonding window; The maximum number of CCEs in a subframe. Assuming that the binding window contains 4 subframes, the first two are downlink subframes not including PHICH, the next one is DwPTS, and the last one is downlink subframe including PHICH. Here, because the DwPTS does not include the PHICH, when the number of OFDM symbols used for the control channel is 1 or 2, the number of CCEs in the DwPTS is equal to that of a general downlink subframe that does not include the PHICH.

Fig. 2 is a schematic diagram of mapping from CCE to ACK/NACK in the present invention. In Example 1, it is assumed that the number of OFDM symbols used for the control channel of the DwPTS in the bundling window is equal to 2, and the number of OFDM symbols used for the control channel of other subframes is equal to 3. Because the number of CCEs N ₃ of the subframe containing ^PHICH is smaller than the number of CCEs N ₃ of other downlink subframes, the number of CCEs in the k=2th CCE block of the subframe containing PHICH is less than that of the other downlink subframes k=the number of CCEs of 2 CCE blocks. The k=2th CCE block of the subframe containing PHICH is mapped to the last ACK/NACK channel, and these reduced N ₃ -N ₃ ^PHICH CCEs do not need to map ACK/NACK, so it is possible to free up a larger Uplink resource block. In Example 2, it is assumed that the number of OFDM symbols used for the control channel in all subframes within the bundling window is equal to 2. Because the number of CCEs N ₂ of the subframe containing ^PHICH is smaller than the number of CCEs N ₂ of other downlink subframes, the number of CCEs in the k=1th CCE block of the subframe containing PHICH is less than that of other downlink subframes k=the number of CCEs in one CCE block. The k=1th CCE block of the subframe containing PHICH is mapped to the last ACK/NACK channel. These reduced N ₂ -N ₂ ^PHICH CCEs do not need to map ACK/NACK, so it is possible to free up a larger uplink resource blocks. In Example 3, it is assumed that the number of OFDM symbols used for the control channel in all subframes within the bundling window is equal to 1. Because the number of CCEs N ₁ PHICH in the subframe containing ^PHICH is smaller than the number N ₁ of CCEs in other downlink subframes, the number of CCEs in the k=0th CCE block of the subframe containing PHICH is less than that in other downlink subframes The number of CCEs of k=0 CCE blocks. The k=0th CCE block of the subframe containing PHICH is mapped to the last ACK/NACK channel. These reduced N ₁ -N ₁ ^PHICH CCEs do not need to map ACK/NACK, so it is possible to free up a larger uplink resource blocks.

Embodiment two:

This embodiment takes the LTE TDD system as an example to describe a method for mapping CCEs to ACK/NACKs by block interleaving when the system bandwidth is small. For a smaller bandwidth, the number of OFDM symbols used for the control channel in a general subframe is 2, 3 or 4, and it is assumed that the number of OFDM symbols used for the control channel in the DwPTS can only be 2. That is, k _max is equal to 3, and k _max ^DwPTS is equal to 1. Define a set of boundary values {N ₀ , N ₁ , N ₂ , N ₃ }, so that the CCEs in each downlink subframe are divided into blocks according to their index order. Here, N ₀ is equal to 0, N ₁ is the maximum number of CCEs in each downlink subframe in the bundling window when the number of OFDM symbols used for the control channel is equal to 2; N ₂ is the maximum number of CCEs used for the control channel When the number of OFDM symbols is equal to ₃ , the maximum number of CCEs in each downlink subframe in the bonding window; The maximum number of CCEs in a subframe. Assuming that the binding window contains 4 subframes, the first two are downlink subframes not including PHICH, the next one is DwPTS, and the last one is downlink subframe including PHICH. Here, because the DwPTS does not include the PHICH, when the number of OFDM symbols used for the control channel is 2, the number of CCEs in the DwPTS is equal to that of a general downlink subframe that does not include the PHICH.

Fig. 3 is a schematic diagram of mapping from CCE to ACK/NACK in the present invention. In Example 1, it is assumed that the number of OFDM symbols used for the control channel of the DwPTS in the bundling window is equal to 2, and the number of OFDM symbols used for the control channel of other subframes is equal to 4. Because the number of CCEs N ₃ of the subframe containing ^PHICH is smaller than the number of CCEs N ₃ of other downlink subframes, the number of CCEs in the k=2th CCE block of the subframe containing PHICH is less than that of the other downlink subframes k=the number of CCEs of 2 CCE blocks. The k=2 CCE block of the subframe containing PHICH is mapped to the last

ACK/NACK channels, and these reduced N ₃ -N ₃ ^PHICH CCEs do not need to map ACK/NACK, so it is possible to free up larger uplink resource blocks. In Example 2, it is assumed that the number of OFDM symbols used for the control channel of the DwPTS in the bundling window is equal to 2, and the number of OFDM symbols used for the control channel of other subframes is equal to 3. Because the number of CCEs N ₂ of the subframe containing ^PHICH is smaller than the number of CCEs N ₂ of other downlink subframes, the number of CCEs in the k=1th CCE block of the subframe containing PHICH is less than that of other downlink subframes k=the number of CCEs in one CCE block. The k=1th CCE block of the subframe containing PHICH is mapped to the last ACK/NACK channel. These reduced N ₂ -N ₂ ^PHICH CCEs do not need to map ACK/NACK, so it is possible to free up a larger uplink resource blocks. In Example 3, it is assumed that the number of OFDM symbols used for the control channel in all subframes within the bundling window is equal to 2. Because the number of CCEs N ₁ PHICH in the subframe containing ^PHICH is smaller than the number N ₁ of CCEs in other downlink subframes, the number of CCEs in the k=0th CCE block of the subframe containing PHICH is less than that in other downlink subframes The number of CCEs of k=0 CCE blocks. The k=0th CCE block of the subframe containing PHICH is mapped to the last ACK/NACK channel, and these reduced N ₁ -N ₁ ^PHICH CCEs do not need to map ACK/NACK, which may free up more uplink resources piece.

Claims (9)

1. A method for mapping CCE to ACK/NACK, comprising steps: a) The user equipment detects the downlink physical control channel and receives downlink data; b) The user equipment obtains the ACK/NACK channel corresponding to the CCE in the uplink subframe according to the boundary value for dividing the CCE in each subframe and whether the current binding window contains DwPTS; c) The user equipment sends the ACK/NACK signal. 2. method according to claim 1, it is characterized in that in step b), when the number of the OFDM symbol of the control channel of corresponding subframe gets different values, boundary value is the CCE number of each downlink subframe in the bonding window the maximum value. 3. The method according to claim 1, wherein in step b), when DwPTS is not included in the current binding window, the CCE blocks of each downlink subframe are interleaved, and the ACK/ NACK channel index. 4. The method according to claim 3, wherein, for the CCE whose index is n _CCE , determine the index k of the CCE block to which it belongs, then the index of the dth downlink subframe is the ACKNACK mapped by the CCE of n _CCE The channel index n _PUCCH ⁽¹⁾ is ${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=(\mathrm{D.}-d-1)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ or

Here, D is the number of subframes in the bonding window, N _k is the boundary value for dividing CCE blocks, N _PUCCH ⁽¹⁾ is a parameter for semi-static configuration, and m is a parameter for reducing ACK/NACK overhead. 5. The method according to claim 1, characterized in that in step b), the current binding window includes DwPTS, the index of each downlink subframe $k<k_{\max }^{\mathrm{wxya}}$ The CCE blocks of each downlink subframe are interleaved, and the ACK/NACK channel indexes to which they are mapped are sequentially calculated. 6. The method according to claim 5, wherein, for the CCE whose index is n _CCE , determine the index k of the CCE block to which it belongs, then the index of the dth downlink subframe is the ACKNACK mapped by the CCE of n _CCE The channel index n _PUCCH ⁽¹⁾ is ${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=(\mathrm{D.}-d-1)\&times;N_{\mathrm{CCE},\mathrm{no}}+d\&times;N_{\mathrm{CCE},\mathrm{no}+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ or

Here, D is the number of subframes in the bonding window, N _k is the boundary value for dividing CCE blocks, N _PUCCH ⁽¹⁾ is a parameter for semi-static configuration, and m is a parameter for reducing ACK/NACK overhead. 7. The method according to claim 1, characterized in that in step b), the current binding window contains DwPTS, the index of each downlink subframe $k\&Greater\; Equal;k_{\max }^{\mathrm{wxya}}$ CCE blocks, and starting from the end position where the first n _DwPTS CCE blocks are mapped to ACK/NACK, interleave the CCE blocks of each downlink subframe except DwPTS, and calculate the ACK/NACK channel index to be mapped to in turn. 8. The method according to claim 7, wherein, for the CCE whose index is n _CCE , determine the index k of the CCE block to which it belongs, then the index of the dth downlink subframe is the ACKNACK mapped by the CCE of n _CCE The channel index n _PUCCH ⁽¹⁾ is ${\mathrm{no}}_{\mathrm{PUCCH}}^{\left(1\right)}=N_{k_{\max }^{\mathrm{wxya}}}+(\mathrm{D.}-d-2)\&times;N_k+d\&times;N_{k+1}+{\mathrm{no}}_{\mathrm{CCE}}+N_{\mathrm{PUCCH}}^{\left(1\right)},$ or

Here, D is the number of subframes in the bonding window, N _k is the boundary value for dividing CCE blocks, N _PUCCH ⁽¹⁾ is a semi-static configuration parameter, k _max ^DwPTS is the number of OFDM symbols used for control channels in DwPTS The number of possible values of the number, m is a parameter to reduce ACK/NACK overhead. 9. The method according to any one of claims 4-8, wherein the ACK/NACK channel corresponding to the downlink physical control channel is calculated according to the smallest index n _CCE among the CCEs of the downlink physical control channel.

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