Patent Description:
In 3GPP LTE standardization process, in release <NUM>, TDD carrier aggregation can only support using the same frame configuration of TDD uplink and downlink between different component carriers. While since release <NUM> evolves to release <NUM>, TDD carrier aggregation between different frequency bands has been able to support using different frame configurations of TDD uplink and downlink between different component carriers. For A/N (ACK/NACK) bit mapping and the resource allocation used for PUCCH format <NUM>, the standardization has reached some agreement. A UE can be configured to have PUCCH format <NUM> or PUCCH format 1b, and have the channel selection used for HARQ-ACK transmission.

In RAN1#68bis meeting, in the case of self-scheduling (i.e. the scheduling of downlink subframe data of a secondary cell is transmitted by the cell), the industry agrees that: the PDSCH HARQ in the secondary cell will refer to the TDD reference uplink and downlink frame configuration. As shown in the following table <NUM>:.

The table shows that when uplink and downlink frame configurations of a primary cell and a secondary cell are certain configurations respectively, which reference frame configuration it is, on which the implementation of HARQ feedback is based. when the frame configuration of a primary cell is the type <NUM>, and the frame configuration of a secondary cell is the type <NUM>, the reference frame configuration on which the implementation of HARQ feedback is based is the type <NUM>.

The reference frame configuration on which HARQ feedback is based is shown in table <NUM>. <NUM>-<NUM> in 3GPP TS <NUM>, and the following table <NUM> lists the table:.

The meaning of the table is that, for seven kinds of uplink and downlink frame configurations respectively, it regulates the HARQ-ACK transmission of which downlink subframe is carried by which uplink subframe. Taking the type <NUM> as an example, No.<NUM> subframe is the only uplink subframe, the uplink subframe is responsible for carrying the HARQ feedback of the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th and 6th downlink subframe counted backward from the uplink subframe.

This kind of relation between the uplink subframe and the downlink subframe, the HARQ feedback of which this uplink subframe carries, can also be called as association, and the set of one or multiple downlink subframes associated with a certain uplink subframe is recorded as K: {k<NUM>,k<NUM>,···kM-<NUM>}.

<NPL> discloses HARQ-ACK feedback for TDD inter-band CA.

Currently for release <NUM>, the agreed solution is that, for the UE configured the PUCCH format <NUM> used for HARQ-ACK transmission, the regulation of HARQ-ACK transmission is the same as release <NUM>, except for the following difference:.

Currently, for the HARQ-ACK transmission transmitted in PUSCH adjusted by UL grants in the uplink subframe n, when the reference frame configuration is the type <NUM>, the industry hasn't agreed about what is the quantity of downlink subframes actually fed back.

And, for the HARQ-ACK transmission transmitted in PUSCH adjusted by UL grants in the uplink subframe n, when the reference frame configuration is the type <NUM>, the industry hasn't agreed about what is the quantity of downlink subframes actually fed back.

Besides, for the case of implementing cross-CC scheduling (i.e. the scheduling information of downlink subframe data of one scheduled cell is transmitted by another scheduling cell), the industry hasn't agreed about how to implement the HARQ-ACK transmission.

In order to fill the above technology blank, according to the first aspect of the invention, a method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network is provided, wherein, the carrier aggregation network comprises self-scheduling a primary cell and a secondary cell, and the method comprises the following steps:.

According to the aspect, in the case that the reference frame configuration is the type <NUM>, it can accurately determine the quantity of downlink subframes actually needing to be fed back, fill the existing technology blank, and avoid resource waste caused by excessive subframes fed back, and also avoid the absent of HARQ information caused by much less subframes fed back.

According to the second aspect of the invention, when the reference frame configuration is the type <NUM>, i.e. the frame configuration of the primary cell and the secondary cell both are the type <NUM>, the invention proposes to continue using the HARQ-ACK transmission design of release <NUM>.

According to the third aspect of the invention, a method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network is proposed, wherein, the carrier aggregation network comprises a scheduling cell and a scheduled cell, and the method comprises the following steps:.

This aspect provides the technical solution of implementing automatically retransmission feedback for the downlink subframe of the scheduled secondary cell when implementing cross-CC scheduling, and fills the existing technology blank.

The preferred embodiment proposes, in the case that the scheduling cell is a primary cell and the scheduled cell is a secondary cell, the HARQ-ACK transmission of the scheduled cell should be based on the HARQ-ACK configuration of the primary cell and should further be unified with downlink subframes of the secondary cell.

The above three technical solutions further propose the detailed solution to implement hybrid automatically retransmitting under different conditions.

The preferred embodiment proposes, in the case that the scheduling cell is a secondary cell and the scheduled cell is a secondary cell, the HARQ-ACK transmission of the scheduled secondary cell should be based on the reference configuration of the scheduling secondary cell and should further be unified with downlink subframes of the scheduling secondary cell and the scheduled secondary cell, wherein, the reference frame configuration is the frame configuration unified between the scheduling secondary cell and the primary cell.

While for the technical solution of implementing hybrid automatically retransmission feedback to the downlink subframes of scheduling secondary cell in implementing scheduling for cross-CC, in the fourth aspect of the invention, a method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network is proposed, the method comprises the following steps:.

In the fourth aspect, it proposes hybrid automatically retransmission feedback of the scheduling secondary cell should be based on the HARQ-ACK transmission of the primary cell and should be the unified with the downlink subframe of the scheduling primary cell.

The advantages of the invention is to fill the blank in the current technology, and to provide detailed solutions of hybrid automatically retransmission feedback in the several cases that are not yet specified, which makes UEs can accurately determine the quantity of downlink subframes actually needing to be fed back and avoid resource waste and insufficient feedback.

By reading the detailed description for unlimited embodiments by referring the following attached drawings, other features, purposes and advantages of the invention will be clearer.

According to an embodiment of the invention, a method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network is provided, wherein, the carrier aggregation network comprises self-scheduling a primary cell and a secondary cell, and the method comprises the following steps:.

In detail, in the carrier aggregation between different frequency bands being able to have different frame configurations, the reference frame configuration of the secondary cell will be determined according to the foregoing table <NUM>.

When the reference frame configuration of a certain secondary cell is the type <NUM>, combined with the specification of table <NUM>, A/N feedback bits of the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th, and 6th downlink subframe before the second uplink subframe should be carried by the second uplink subframe.

Since in the frame configuration of the secondary cell, the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th, 6th subframes before the second uplink subframe are not necessarily downlink subframes, i.e. not necessarily needing to implement A/N feedback, thus, it should determine the actual downlink subframes of the secondary cell in the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th, 6th subframes before the second uplink subframe, according to the actual frame configuration of the secondary cell, i.e. the downlink subframes of the secondary cell being able to implement feedback, recorded as Kc, whose subframe quantity is Mc.

And, for a primary cell and a secondary cell respectively, the UE receives the physical downlink shared channel and physical downlink control channel, and thus determines respectively the quantity Uc of downlink subframes needing to feed back, respectively of the primary cell and the secondary cell. And, the UE determines the maximum U in the quantity Uc of downlink subframes needing to feed back, of the primary cell and the secondary cell respectively.

The UE extracts the parameter <MAT> from the DCI <NUM>/<NUM> field of the uplink grant, and calculates the second quantity N according to the parameter <MAT> and the maximum quantity U. Specially, N is calculated according to the following formula: <MAT>, wherein, ┌ ┐ is ceiling function symbol.

Then, the UE takes the smaller value of the first quantity Mc and the second quantity N as the actual quantity <MAT>, i.e. <MAT>.

When implementing hybrid automatically retransmission feedback, the UE implements automatically retransmission feedback for downlink frames of the actual quantity <MAT> in the physical shared channel, adjusted by uplink grants, in the uplink subframes.

The following will describe the above embodiment combined with a detailed example.

As shown in <FIG>, the frame configuration of the primary cell is the type <NUM>, the frame configuration of the secondary cell is the type <NUM>. According to table <NUM>, the HARQ-ACK for the secondary cell should meet the type <NUM>, i.e. the reference frame configuration of the secondary cell is the type <NUM>.

The HARQ-ACK transmission is scheduled in the uplink subframe #<NUM> of the third frame. The downlink subframe set Kc associated with the uplink subframe #<NUM> includes the downlink subframe with serial number n-k, wherein k ∈ K, and K is the item { <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} corresponding to the uplink subframe #<NUM> of the type <NUM> in table <NUM>. In <FIG>, the 13th, 12th, 9th, 8th, 7th, 5th, 4th, 11th, 6th subframes before the uplink subframe #<NUM> of the third frame are marked with oblique lines.

Next, according to the frame configuration type <NUM> of the secondary cell, it determines that in these subframes, the previous 13th, 12th, and 11th and the previous 7th, 6th, 5th, and 4th subframes are downlink subframes, the automatically retransmission feedback of the seven downlink subframes should be fed back in the uplink subframe #<NUM> of the third frame, shown as the lines in <FIG>, and they constitute the set Kc. Thus, based on the type <NUM> of the time slot configuration, the first quantity Mc of the downlink subframe Kc of the secondary cell that can be fed back in the uplink subframe #<NUM> of the third frame, is <NUM>.

And, the HARQ-ACK transmission is scheduled by the uplink grant into the PUSCH of the uplink subframe #<NUM> of the third frame, and the MSB and LSB of the DCI <NUM>/<NUM> in the uplink grant are <NUM>, i.e. representing the parameter, transmitted from a base station, about the number of downlink subframes fed back is <MAT>.

In the actual communication, on the side of UEs, for the communication of a primary cell, it receives four downlink subframes, and U<NUM> =<NUM> ; for the communication of a secondary cell, as shown in <FIG>, the 7th downlink subframe before the uplink subframe #<NUM> of the third frame does not have downlink transmission, the UE successfully receives the communication of other six downlink subframes, and U<NUM> =<NUM>. Then, U = max {<NUM>, <NUM>} =<NUM> , and the UE can calculate to obtain the second quantity <MAT>.

Finally, base on the embodiment of the invention, the actual quantity of downlink subframes actually fed back is <MAT>.

The embodiment of the invention can accurately determine the quantity of downlink subframes actually fed back in the PUSCH, without needing other redundant feedback.

For the case of implementing cross-CC scheduling, in the case that the secondary cell is scheduled by the primary cell, the technical solution proposed by the inventor is that the hybrid automatically retransmission feedback of downlink subframes of the secondary cell should complies with the feedback configuration of the primary cell.

According to the second embodiment of the invention, a method of implementing automatically retransmission feedback in a UE in a carrier aggregation network is provided, wherein, the carrier aggregation network comprises a scheduling cell and a scheduled cell, the scheduling cell is a primary cell, the scheduled cell is a secondary cell, and the method comprises the following steps:.

In detail, for the UE configured with the PUCCH format <NUM> used for the HARQ-ACK transmission, the HARQ-ACK transmission should continue using the regulation of release <NUM>, except for the following each items:.

As shown in <FIG>, the frame configuration of the primary cell and secondary cell are unified with those in <FIG> , the frame configuration of the primary cell is the type <NUM>, and the frame configuration of the secondary cell is the type <NUM>. For the #<NUM> uplink subframe of the second subframe, the downlink subframe set Kc associated with it includes the downlink subframe which serial number is n-k, wherein k∈ K , and K is the item {<NUM>, <NUM>, <NUM>, <NUM>} corresponding to the uplink subframe #<NUM> of the type <NUM> in table <NUM>. As shown in <FIG>, the 8th, 7th, 4th, 6th subframes before the uplink subframe #<NUM> of the second frame are marked with lines.

When cross-CC scheduling, only when the subframes of the scheduling cell and the scheduled cell are both downlink subframes, the scheduling cell can schedule the downlink transmission in the scheduled cell. Thus, it should determine the actual downlink subframes of the secondary cell in the previous 8th, 7th, 4th, 6th subframes of the uplink subframe #<NUM>, according to the actual frame configuration of the secondary cell, i.e. the downlink subframes of the secondary cell that can be fed back, recorded as <MAT>, and its subframe quantity <MAT>. As shown in <FIG>, for the previous 4th subframe of the uplink subframe #<NUM>, the scheduled cell is not a downlink subframe. Thus, the downlink subframe <MAT> of the secondary cell that can be fed back is the previous 8th, 7th, 6th subframes of the uplink subframe #<NUM>, as shown in <FIG>, <MAT> is <NUM>.

Next, if the HARQ-ACK transmitted in the uplink subframe #<NUM> of the second frame is transmitted in the PUCCH or the PUSCH not adjusted by UL grants, the actual quantity <MAT> of downlink subframes actually fed back is the quantity <MAT> of downlink subframes in the downlink subframe set Kc that can be fed back, i.e. <MAT>.

If the HARQ-ACK transmitted in the uplink subframe #<NUM> of the second frame is transmitted in the PUSCH adjusted by UL grants, we set up the following scenario: in the subframe #<NUM> of the first frame and the subframe #<NUM> of the second frame, cross-CC scheduling the UE to receive the PUCCH or PDSCH needing automatically retransmission feedback in these subframes of the scheduled cell, and the scheduling cell doesn't have a downlink transmission in the subframe #<NUM> of the second frame, as shown in <FIG>, i.e. not cross-CC scheduling the UE to receive the PUCCH or PDSCH in this subframe of the scheduled cell, thus <MAT> transmitted by the base station, i.e. indicating that the UE needs to transmit the automatically retransmission feedback of the subframe #<NUM> of the first frame and the subframe #<NUM> of the second frame. Thus, according to the embodiment of the invention, <MAT>.

For the case of implementing cross-CC scheduling, in the case that the secondary cell is scheduled by another secondary cell, the technical solution proposed by the inventor is that for the scheduling secondary cell, its automatically retransmission feedback for downlink subframes should complies with the reference configuration based on the primary cell and the scheduling secondary cell, and considers the downlink subframe location of the scheduled secondary cell; while for the scheduled secondary cell, its automatically retransmission feedback for downlink subframes should complies with the reference configuration based on the primary cell and the scheduling secondary cell, and considers the downlink subframe location of the scheduling secondary cell and the scheduled secondary cell. In detail:
For implementing hybrid automatically retransmission feedback for downlink subframes of the scheduling secondary cell, the invention proposes a method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network, wherein, the carrier aggregation network comprises a scheduling secondary cell, the method implements automatically retransmission feedback for downlink frames of the scheduling secondary cell, wherein, the method comprises the following steps:.

The method further comprises the following steps:.

wherein, the fourth quantity N‴ is calculated according to the following formula:
<MAT>, wherein, <MAT> is the parameter, and U is the maximum quantity in the quantities of downlink subframes needing to be fed back for the primary cell and the scheduling secondary cell.

For implementing hybrid automatically retransmission feedback for downlink subframes of the scheduled secondary cell, the technical solution proposed by the invention is that: the automatically retransmission feedback of downlink subframes of the secondary cell should complies with the reference frame configuration of the scheduling secondary cell.

In detail, according to the second embodiment of the invention, a method of implementing automatically retransmission feedback in a UE in a carrier aggregation network is provided, wherein, the carrier aggregation network comprises a scheduling cell and a scheduled cell, the scheduling cell is a primary cell, the scheduled cell is a secondary cell, and the method comprises the following steps:.

In principle, after determining the downlink subframes <MAT> needing to be fed back, and determining the first quantity Mc" of the downlink subframes Kc" needing to be fed back, for various cases of implementing feedback in the PUCCH or PUSCH, the operation the UE implementing is similar with the embodiment <NUM>.

Certainly, there are other multiple embodiments in the invention, without departing from the scope of the invention, as defined by the claims.

Claim 1:
A method of implementing hybrid automatically retransmission feedback in a UE in a carrier aggregation network according to the long term evolution, LTE, standard, wherein, the carrier aggregation network comprises a self-scheduling primary cell and a secondary cell, and the method comprises the following steps:
i. determining a reference frame configuration of type <NUM>;
ii. determining a first quantity, Mc, of downlink subframes , Kc, of the secondary cell needing to be acknowledged in uplink subframes, according to a frame configuration of the secondary cell and the reference frame configuration ;
iii. receiving from a base station a parameter , <MAT>, and calculating a second quantity , N, of downlink subframes needing to be acknowledged in the uplink subframes, based on the parameter as <MAT> wherein ┌ ┐ denotes the ceiling function and U denotes a maximum quantity in quantities of downlink subframes needing to be acknowledged for the primary cell and the secondary cell;
iv. determining an actual quantity , <MAT>, of downlink subframes actually needing to be acknowledged, based on the first quantity , Mc, and the second quantity , N, by taking the smaller value of the first quantity, Mc, and the second quantity , N, as the actual quantity , <MAT>;
v. implementing automatically retransmission feedback for downlink frames of the actual quantity , <MAT>, in a physical shared channel, adjusted by uplink grants, in the uplink subframes.