WO2012122755A1

WO2012122755A1 - Adaptive transmission method and apparatus for physical downlink control channel

Info

Publication number: WO2012122755A1
Application number: PCT/CN2011/076224
Authority: WO
Inventors: 谭源春; 周晖
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-03-11
Filing date: 2011-06-23
Publication date: 2012-09-20
Also published as: CN102685893A; CN102685893B

Abstract

The present invention discloses an adaptive transmission method for a physical downlink control channel (PDCCH), including: by checking a discontinuous transmission (DTX) information of a user, a base station adjusts an outer-loop factor to obtain the current outer-loop factor; according to the current outer-loop factor, the base station assigns the control channel element (CCE) resources satisfying the target block error rate (BLER) to the PDCCH of the user. The present invention also correspondingly discloses an adaptive transmission apparatus for the PDCCH. The present invention controls the CCE aggregation used by the PDCCH through checking the DTX information of the user by the base station, thereby improving the reliability of the PDCCH and guaranteeing the system performance of the PDCCH.

Description

PDCCH adaptive transmission method and device

The present invention relates to a PDCCH (High Speed Physical Downlink Control Channel) adaptive transmission technology, and in particular, to a PDCCH adaptive transmission method and apparatus. Background technique

The PDCCH is composed of a CCE (Control Channel Element) and is used to carry DCI (Downlink Control Information) in the Long-Term Evolution (TE) technology.

In the scenario of multi-cell and multi-user, the location of the cell and the status of each cell are different. If some users are walking and some users are in-vehicle, the PDCCH needs to be adaptively transmitted to ensure the reliability of PDCCH transmission. .

In the prior art, the CCE aggregation degree of the PDCCH is controlled by the downlink quality information, such as the CQI (Channel Quality Indicator) and the RSRP (Reference Signal Receiving Power), to ensure the reliability of the PDCCH. . However, the reliability of the above method is low, and the system performance of the PDCCH cannot be guaranteed. Summary of the invention

An object of the present invention is to provide a PDCCH adaptive transmission method and apparatus, which are used to solve the problem that the PDCCH has poor reliability and cannot guarantee the performance of the PDCCH system.

According to an aspect of the present invention, a PDCCH adaptive transmission method is provided, including the following steps:

The base station passes DTX (Discontinuous Transmission) information to the user. Detection, adjusting the outer loop factor to obtain the current outer loop factor;

The base station allocates a CCE resource that meets a target BLER (Block Error Ratio) to the PDCCH of the user according to the current outer ring factor.

Preferably, when the base station detects the DTX information of the user, the base station adds an increase step to the outer loop factor;

When the base station does not detect the DTX information of the user, the base station reduces the outer loop factor by one down step.

Preferably, the method further includes:

The base station determines the value of the up-stepping step and the value of the down-stepping step according to the target BLER.

Preferably, the base station allocates a CCE resource that satisfies the BLER to the PDCCH of the user according to the current outer ring factor:

The base station obtains the current CCE aggregation degree according to the current outer loop factor;

The base station allocates a CCE resource corresponding to the current CCE aggregation degree to the PDCCH of the user.

Preferably, the base station obtains the current CCE aggregation degree according to the current outer ring factor, including:

The base station obtains the value of the CCE aggregation degree corresponding to the current outer loop factor according to the mapping relationship between the outer loop factor and the value of the CCE aggregation degree;

The base station determines the current CCE aggregation degree according to the value of the CCE aggregation degree corresponding to the current outer ring factor. According to another aspect of the present invention, a PDCCH adaptive transmission apparatus is provided, including: a DTX detection unit, configured to detect DTX information of a user;

An outer loop adjustment unit, configured to adjust an outer loop factor according to DTX information to obtain a current outer loop factor;

And a resource allocation unit, configured to allocate, according to the current outer ring factor, a physical downlink control channel PDCCH of the user to a control channel unit CCE resource that satisfies the target BLER.

Preferably, the outer ring adjustment unit comprises:

Up-regulating sub-unit, used to increase the outer loop factor when detecting the user's DTX information Step up;

The sub-unit is adjusted to reduce the outer loop factor by one down step when no DTX information of the user is detected.

Preferably, the outer ring adjustment unit further includes:

The step size calculation sub-unit is configured to determine the value of the step-up step and the value of the step-down step according to the target BLER.

Preferably, the resource allocation unit comprises:

The CCE aggregation degree obtaining sub-unit is configured to obtain a CCE aggregation degree corresponding to the current outer ring factor according to the mapping relationship between the outer ring factor and the CCE aggregation degree, and determine the current value according to the CCE aggregation degree corresponding to the current outer ring factor. CCE polymerization degree;

The CCE allocation sub-unit is configured to allocate a CCE resource corresponding to the current CCE aggregation degree to the PDCCH of the user.

Compared with the prior art, the present invention has the following advantages: The present invention controls the CCE aggregation degree used by the PDCCH by detecting the DTX information of the user by the base station, thereby improving the reliability of the PDCCH and ensuring the performance of the PDCCH system. DRAWINGS

1 is a schematic flowchart of a PDCCH adaptive transmission method provided by the present invention; FIG. 2 is a schematic structural diagram of a PDCCH adaptive transmission apparatus provided by the present invention; and FIG. 3 is a schematic diagram of a base station detecting DTX information of a PDCCH downlink according to the present invention. ;

FIG. 3b is a schematic diagram of a base station detecting DTX information of a PDCCH uplink according to the present invention; FIG.

4 is a flowchart of an implementation of a PDCCH adaptive transmission processing method provided by the present invention. detailed description

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic flowchart of a PDCCH adaptive transmission method provided by the present invention. As shown in FIG. 1, the process includes:

Step S101: The base station detects the DTX information of the user. When the DTX information of the user is detected, the outer loop factor of the user is increased by an upward adjustment step. When the DTX information of the user is not detected, the outer loop factor of the user is decreased. A down step to get the current outer loop factor.

Here, the value of the up-step step and the value of the down-step are determined by the base station according to the target BLER. In step S102, the base station obtains the value of the CCE aggregation degree corresponding to the current outer loop factor according to the mapping relationship between the outer loop factor and the value of the CCE aggregation degree, and the CCE aggregation degree corresponding to the value of the CCE aggregation degree is the current CCE aggregation degree, and the base station A CCE resource corresponding to the current CCE aggregation degree is allocated to the PDCCH of the user.

Here, the CCE resource represents the number of allocated CCEs, which is determined according to the degree of CCE aggregation.

FIG. 2 shows a schematic structural diagram of a PDCCH adaptive transmission apparatus provided by the present invention. As shown in FIG. 2, the apparatus includes a DTX detection unit, an outer loop adjustment unit, and a resource allocation unit.

The DTX detection unit is configured to detect whether the current TTI (Transmission Time Interval) of the user is DTX.

The outer loop adjusting unit calculates an outer loop factor of the current user according to the output result of the DTX detecting unit, and specifically includes a step calculating subunit, a lifting subunit, and a down subunit; wherein the step calculating subunit calculates the outer loop according to the target BLER The value of the step-up step and the value of the step-down step required for the factor adjustment;

When the output of the DTX detection unit is that the DTX information of the user is detected, the upper loop sub-unit adds an up-step step to the outer loop factor, thereby obtaining the current outer loop factor; When the output of the DTX detection unit is that the DTX information of the user is not detected, the outer loop factor is reduced by one down step, thereby obtaining the current outer loop factor.

The resource allocation unit calculates the CCE aggregation degree of the target BLER that is used by the user in the PDCCH of the current TTI according to the current outer ring factor obtained by the outer ring adjustment unit, and allocates corresponding CCE resources to the PDCCH of the user according to the CCE aggregation degree. The CCE resource represents the number of allocated CCEs, which is determined according to the CCE aggregation degree. As shown in FIG. 2, the resource allocation unit specifically includes a CCE aggregation degree obtaining subunit and a CCE allocation subunit;

The CCE aggregation degree obtaining sub-unit obtains the value of the CCE aggregation degree corresponding to the current outer ring factor according to the mapping relationship between the outer ring factor and the CCE aggregation degree, and obtains the corresponding value according to the CCE aggregation degree corresponding to the current outer ring factor. CCE polymerization degree, which is the current CCE polymerization degree;

The CCE allocation sub-unit allocates a CCE resource corresponding to the current CCE aggregation degree output by the CCE aggregation degree acquisition sub-unit to the PDCCH of the user.

FIG. 3a is a schematic diagram of a base station for detecting downlink DTX information of a PDCCH according to the present invention. As shown in FIG. 3a, a base station transmits uplink DCI1 information through a PDCCH at time a, and detects ACK information fed back by a user at time b. The DCI1 information is transmitted through the PDCCH at time c. Since the user does not receive the DCI1 information, the base station checks the DTX information at time d.

FIG. 3b is a schematic diagram of the base station detecting DTX information of the PDCCH uplink according to the present invention. As shown in FIG. 3b, the base station side a time transmits downlink DCI0 information through the PDCCH, and detects the PUSCH information sent by the user at time b. The DCIO information is transmitted through the PDCCH at time c. Since the user does not receive the DCIO information, the base station checks the DTX information at time d.

FIG. 4 shows an implementation flow of a PDCCH adaptive transmission processing method provided by the present invention. As shown in FIG. 4, the process includes:

Step S401: The base station detects DTX information of the user in the current TTI, and if the user does not receive the DCI1 and does not perform ACK/NACK feedback, or if the user does not receive the DCIO, does not send When the PUSCH is sent, the base station will detect the DTX information of the user.

Step S402, determining, according to the result of step S401, whether the DTX information of the user is detected. If the base station detects the DTX information of the current user, the process proceeds to step S403. If the base station does not detect the DTX information of the user in the current TTI, Then, the process proceeds to step S404.

Step S403, the base station adds an uplink step to the outer loop factor DeltaCCEdB of the user.

StepUp, the formula is as follows:

DeltaCCEdB=DeltaCCEdB+StepUp (丄)

Step S404, the base station reduces the outer loop factor DeltaCCEdB of the user by one downward step.

StepDown, the formula is as follows:

DeltaCCEdB=DeltaCCEdB-StepDown In step S403 and step S404, the target BLER is the TargetBler, the step-up stepStepU and the down-step step StepDown and the TargetBler can be obtained according to a certain relationship, for example, according to the relationship StepUp: StepDown=(l -TargetBler ) : TargetBler gets, if TargetBler is 1%, StepU: StepDown=( 1 -TargetBler) : TargetBler=99: 1 , where StepUp cannot exceed 3dB.

Step S405: The base station allocates, according to the outer loop factor DeltaCCEdB, the CCE resource that satisfies the target BLER for the PDCCH of the user.

Specifically, the base station determines the dB value of each CCE aggregation degree in the CCE aggregation degree set according to the CCE aggregation degree CCEinit initially used by the user, where CCEinit is 0 dB. For example, if the CCE aggregation degree is set to { 1,2,4,8} and CCEinit is 8, the CCE polymerization degree 1 is -9 dB, the CCE polymerization degree 2 is -6 dB, the CCE polymerization degree 4 is -3 dB, and the CCE polymerization degree is The relationship between the CCEalloc and the CCE aggregation degree dB value PDCCHres is as follows:

PDCCHres = 10 * log lO{CCEalloci/ CCEinit) ( ₃ ) The user's outer ring factor DeltaCCEdB at the current TTI is mapped to the dB value of the appropriate CCE aggregation degree. For example, the user can put the outer loop factor DeltaCCEdB pair of the user at the current frame. The dB value of the closest CCE polymerization degree should be taken. If there is two dB values corresponding to the CCE polymerization degree corresponding to DeltaCCEdB, a large dB value is taken.

Determining the CCE aggregation degree corresponding to the dB value according to the dB value of the CCE aggregation degree corresponding to the outer loop factor DeltaCCEdB, the CCE aggregation degree is the CCE aggregation degree used by the user at the current time, that is, the current CCE aggregation degree, and the base station The user currently uses the current CCE aggregation degree to perform PDCCH transmission.

In addition, the CCE aggregation degree used by the set PDCCH of the user may be set to the maximum CCE aggregation degree 8 or other values may be set, and any aggregation degree in the CCE aggregation degree set may be used as the initial value of the CCE aggregation degree.

Set the initial value of the user's outer loop factor DelataCCEdB, which can be set to 0.

The flow of Fig. 4 will be specifically described below by means of two embodiments.

Embodiment 1

Let the target PDCCH of the user's PDCCH be 1%, StepU be 0.99dB, StepDown be O.OldB, the initial CCE aggregation degree CCEinit is 8, and the current TTI user's outer loop factor DelataCCEdB is -2dB.

If the user does not receive DCI1 and does not perform ACK/NACK feedback, the base station detects the DTX information of the user at the current time. Therefore, the base station adds an up step StepUp to the outer ring factor of the user, and the current outer ring factor is -1.01. dB.

The base station determines the dB value of each CCE aggregation degree in the CCE aggregation degree set according to the CCE aggregation degree CCEinit initially used by the user, where CCEinit is OdB, CCE aggregation degree set is {1, 2, 4, 8}, CCE aggregation degree CCEinit When it is 8, the CCE polymerization degree 1 is -9 dB, the CCE polymerization degree 2 is -6 dB, the CCE polymerization degree 4 is -3 dB, and the CCE polymerization degree 8 is OdB.

The user's outer loop factor -1.01 is closest to OdB at the current frame. Therefore, the user's outer loop factor -1.01 of the current TTI corresponds to OdB. According to the dB value OdB of the CCE aggregation degree corresponding to the outer loop factor DeltaCCEdB, the CCE polymerization degree used by the user in the current TTI is obtained as the dB value. The corresponding CCE polymerization degree is 8.

The base station transmits the PDCCH to the user at the current CCE aggregation degree 8. Embodiment 2

Let the target PDCCH of the user's PDCCH be 1%, StepU be 0.99dB, StepDown be O.OldB, the initial CCE aggregation degree CCEinit is 8, and the current TTI user's outer loop factor DelataCCEdB is -3.02dB.

The base station does not detect the DTX information of the user at the current time, so the base station reduces the outer loop factor of the user by one down step StepDown, and the current outer loop factor is -3.03 dB.

The base station determines the dB value of each CCE aggregation degree in the CCE aggregation degree set according to the CCE aggregation degree CCEinit initially used by the user, so that CCEinit is OdB, the CCE aggregation degree set is {1, 2, 4, 8}, and the CCE aggregation degree CCEinit is 8 , the CCE polymerization degree 1 is -9 dB, the CCE polymerization degree 2 is -6 dB, the CCE polymerization degree 4 is -3 dB, and the CCE polymerization degree 8 is OdB.

The user's outer loop factor -3.03 is closest to -3dB, so the user's current outer loop factor -3.03 corresponds to -3dB. According to the dB value of the CCE aggregation degree corresponding to the outer loop factor DeltaCCEdB -3dB, the CCE aggregation degree corresponding to the dB value used by the user in the current 为 is obtained as 4, which is the CCE aggregation degree corresponding to the dB value.

The base station transmits the PDCCH to the user at the current CCE aggregation degree 4. In summary, the present invention has the following technical effects: The present invention controls the CCE aggregation degree used by the PDCCH of the user by detecting the DTX information of the user by the base station, thereby improving the reliability of the PDCCH to a large extent.

Although the invention has been described in detail above, the invention is not limited thereto, and various modifications may be made by those skilled in the art in accordance with the principles of the invention. Therefore, modifications in accordance with the principles of the invention should be understood as falling within the scope of the invention.

Claims

Claim

A PDCCH adaptive transmission method for a physical downlink control channel, the method comprising:

The base station adjusts the outer loop factor by detecting the discontinuous transmission DTX information of the user to obtain the current outer loop factor;

The base station allocates a control channel element CCE resource that satisfies the target error rate BLER for the PDCCH of the user according to the current outer ring factor.

2. The method according to claim 1, wherein the base station adjusts the outer loop factor by detecting the non-continuous transmission of the DTX information of the user:

When the base station detects the DTX information of the user, the base station adds an uplink step to the outer loop factor; when the base station does not detect the DTX information of the user, the base loop factor decreases by one down step.

3. The method according to claim 2, wherein the method further comprises: the base station determining a value of the step-up step and a value of the step-down step according to the target BLER.

The method according to claim 3, wherein the base station allocates a CCE resource satisfying the BLER to the PDCCH of the user according to the current outer ring factor:

The base station obtains a current CCE aggregation degree according to the current outer ring factor;

The method according to claim 4, wherein the base station obtains the current CCE aggregation degree according to the current outer loop factor, including:

The base station determines the current CCE aggregation degree according to the value of the CCE aggregation degree corresponding to the current outer ring factor.

A PDCCH adaptive transmission device, the device comprising: a DTX detection unit, an outer loop adjustment unit, and an outer loop adjustment unit; The DTX detecting unit is configured to detect DTX information of the user;

The outer loop adjustment unit is configured to adjust an outer loop factor according to the DTX information, where the resource allocation unit is configured to allocate a CCE resource that satisfies a target BLER according to the current outer loop factor.

The device according to claim 6, wherein the outer ring adjusting unit includes a toping subunit and a downregulating subunit;

The up-conversion sub-unit is configured to: when the DTX information of the user is detected, increase an outer step factor by an increase step size;

The down-conversion sub-unit is configured to reduce the outer loop factor by one down-step step when the DTX information of the user is not detected.

The device according to claim 7, wherein the outer ring adjusting unit further comprises:

The device according to claim 8, wherein the resource allocation unit includes a CCE aggregation degree acquisition subunit and a CCE allocation subunit;

The CCE aggregation degree obtaining sub-unit is configured to obtain a CCE aggregation degree corresponding to the current outer ring factor according to a mapping relationship between the outer ring factor and the CCE degree of polymerization, and according to the current outer ring factor corresponding CCE polymerization degree Value determines the current CCE aggregation degree;

The CCE allocation subunit is configured to allocate a CCE resource corresponding to the current CCE aggregation degree to the PDCCH of the user.