CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of PCT Application No. PCT/CN2017/106491 filed on Oct. 17, 2017, which claims a priority to Chinese Patent Application No. 201611146857.x filed on Dec. 13, 2016, the disclosure of which is incorporated in its entirety by reference herein.

TECHNICAL FIELD

The present disclosure relates to the field of communication technology, in particular to a method for data transmission, a base station and a terminal.

BACKGROUND

A wireless communication system includes at least one transmitter and one receiver. In a downlink transmission of a cellular communication system, a transmitter is a base station (such as an eNB in 3GPP LTE) and a receiver is a user equipment (UE). The eNB transmits a downlink reference signal, and the UE receives the downlink reference signal to perform a channel measurement. Various types of reference signals (RSs) may be supported depending on different purposes of the channel measurement. For example, in 3GPP LTE, channel state information reference signal (CSI-RS) is used in channel measurement and channel state information (CSI) feedback. The system performs a selection from multiple CSI-RS resource configurations, and here each CSI-RS resource configuration uniquely determines one group of time and frequency resources (such as a resource element RE) for transmitting the CSI-RS. In LTE, a UE may be semi-statically configured with one or more CSI-RS resources. Each CSI-RS is transmitted periodically, that is, the CSI-RS is merely transmitted in a pre-defined set of subframes, and a period and a subframe offset of a periodic CSI-RS are semi-statically configured to the UE. When the UE receives downlink data (such as a physical downlink shared channel (PDSCH)), an RE for transmitting the CSI-RS cannot be used for transmitting the PDSCH; hence, PDSCH rate matching needs to be performed in consideration of the semi-statically configured periodic CSI-RS.

The above-described CSI-RS has a non-zero transmission power and is defined as a NZP-CSI-RS. In addition, a network may further configure one or more periodic zero-power CSI-RS (ZP-CSI-RS) resources, and PDSCH rate matching needs to be performed in consideration of these configured periodic CSI-RS resources.

Subframe periods and subframe offsets of periodic transmissions for the ZP-CSI-RS and the NZP-CSI-RS are indicated by a subframe configuration signaling subframe_config in a high-layer signaling information element (IE) region, where the subframe_config is a part of resource configurations for the ZP-CSI-RS and the NZP-CSI-RS.

Aperiodic CSI-RS is recently introduced to support RS sharing among different REs and to achieve higher spectrum efficiency. One example of such aperiodic CSI-RS is an aperiodic CSI-RS (a aperiodic CSI-RS which is transmitted merely once) which can be transmitted in one-shoot manner in any subframe. Since the aperiodic CSI-RS can be transmitted anywhere in time domain, it does not need configuration by subframe_config. In a case that the eNB is configured with multiple aperiodic CSI-RS resources, it may be indicated, through a dynamic signaling, that one or more aperiodic CSI-RSs are to be transmitted in a certain subframe.

Another example of aperiodic CSI-RS is a multi-shot CSI-RS, which is an aperiodic CSI-RS transmitted multiple times. A period and a subframe offset of the multi-shot CSI-RS still need to be configured by a high-layer signaling and indicated by the IE field of subframe_config; in this way, the multi-shot CSI-RS is transmitted periodically. Transmission of a multi-shot CSI-RS is only performed after it is activated by the eNB, and is stopped when deactivated by the eNB.

With the introduce of the aperiodic CSI-RS, a downlink control signaling for scheduling a data transmission needs to be enhanced. That is, the eNB needs to indicate the UE whether an aperiodic CSI-RS is transmitted and indicate the UE about a configuration of the aperiodic CSI-RS if the aperiodic CSI-RS is transmitted. In this way, the UE may perform PDSCH rate matching correctly.

However, no solution is given to ensure that the UE can perform the PDSCH rate matching correctly after the aperiodic CSI-RS is introduced, so data cannot be transmitted correctly.

SUMMARY

The present disclosure is to provide a method for data transmission, a base station and a terminal, which may solve a problem in relevant technology that data cannot be correctly transmitted with introduce of an aperiodic CSI-RS.

Regarding the above problem, some embodiments of the present disclosure provide a method for data transmission applied to a base station. The method includes:

configuring the number of bits occupied by downlink control information (DCI) used to indicate physical downlink shared channel (PDSCH) scheduling on each of all carriers corresponding to a to-be-scheduled terminal to be N, where N is a maximum number of bits occupied by the DCI that is used to indicate the PDSCH scheduling on a carrier configured with an aperiodic channel state information reference signal (CSI-RS); and

constructing scheduling information for indicating the PDSCH scheduling based on the configured DCI, and transmitting the scheduling information to the to-be-scheduled terminal.

Optionally, the configuring the number of bits occupied by the DCI used to indicate the PDSCH scheduling on each of all carriers corresponding to the to-be-scheduled terminal to be N includes:

adding an aperiodic zero-power (ZP) CSI-RS indication field occupying a corresponding number of bits to the DCI of each carrier based on the N.

Optionally, the adding the aperiodic ZP CSI-RS indication field occupying the corresponding number of bits to the DCI of a carrier that is not configured with an aperiodic CSI-RS includes:

padding the aperiodic ZP CSI-RS indication field with values preset between the base station and a terminal, or with self-configured values.

Optionally, for carriers configured with aperiodic CSI-RSs, each state corresponding to values of bits in the aperiodic ZP CSI-RS indication field on each carrier indicates both a CSI process index and a ZP CSI-RS index.

Optionally, before configuring the aperiodic CSI-RS, the method for data transmission further includes:

configuring, by a radio resource control (RRC), the CSI process index and the ZP CSI-RS index corresponding to each state; or

predefining, in a system, the CSI process index and the ZP CSI-RS index corresponding to each state.

The present disclosure further provides a method for data transmission applied to a terminal, including:

receiving scheduling information for indicating physical downlink shared channel (PDSCH) scheduling transmitted by a base station, where the number of bits occupied by downlink control information (DCI) in the scheduling information is a maximum number of bits occupied by the DCI that is used to indicate the PDSCH scheduling on a carrier configured with an aperiodic channel state information reference signal (CSI-RS); and

performing PDSCH rate matching based on the scheduling information.

Optionally, the scheduling information includes an aperiodic zero-power (ZP) CSI-RS indication field that is newly added to the DCI.

Optionally, in a case that the DCI is DCI of a carrier configured with an aperiodic CSI-RS, the step of performing the PDSCH rate matching based on the scheduling information includes: obtaining values of bits of a part of or all of an area in the scheduling information, where the area is used to indicate the PDSCH rate matching and includes the aperiodic ZP CSI-RS indication field; and performing the PDSCH rate matching based on a state corresponding to the values of the bits.

Optionally, in a case that the DCI is DCI of a carrier not configured with an aperiodic CSI-RS, the performing PDSCH rate matching based on the scheduling information includes: obtaining values of bits of a part of or all of an area in the scheduling information, where the area is used to indicate the PDSCH rate matching and does not include the aperiodic ZP CSI-RS indication field; and performing the PDSCH rate matching based on a state corresponding to the values of the bits.

Optionally, before performing PDSCH rate matching based on the scheduling information, the method for data transmission further includes: decoding the DCI based on the maximum value.

The present disclosure further provides a base station, including: a configuration module, used to configure the number of bits occupied by downlink control information (DCI) used to indicate physical downlink shared channel (PDSCH) scheduling on each of all carriers corresponding to a to-be-scheduled terminal to be N, where N is a maximum number of bits occupied by the DCI that is used to indicate the PDSCH scheduling on a carrier configured with an aperiodic channel state information reference signal (CSI-RS); and a first processing module, configured to construct scheduling information for indicating the PDSCH scheduling based on the configured DCI, and transmit the scheduling information to the to-be-scheduled terminal.

Optionally, the configuration module is used to: add an aperiodic zero-power (ZP) CSI-RS indication field occupying a corresponding number of bits to the DCI of each carrier based on the N.

Optionally, for a carrier that is not configured with an aperiodic CSI-RS, the configuration module includes a padding sub-module, configured to pad the aperiodic ZP CSI-RS indication field with values preset between the base station and a terminal, or with self-configured values.

Optionally, for carriers configured with aperiodic CSI-RSs, each state corresponding to values of bits in the aperiodic ZP CSI-RS indication field on each carrier indicates both a CSI process index and a ZP CSI-RS index.

Optionally, the base station further includes a second processing module used to: configure, by a radio resource control (RRC), the CSI process index and the ZP CSI-RS index corresponding to each state or predefine, in a system, the CSI process index and the ZP CSI-RS index corresponding to each state, before the aperiodic CSI-RS is configured.

The present disclosure further provides a terminal, including: a receiving module, used to receive scheduling information for indicating a physical downlink shared channel (PDSCH) scheduling transmitted by a base station, where the number of bits occupied by downlink control information (DCI) in the scheduling information is a maximum number of bits occupied by the DCI that is used to indicate the PDSCH scheduling on a carrier configured with an aperiodic channel state information reference signal (CSI-RS); and a matching module, used to perform PDSCH rate matching based on the scheduling information.

Optionally, the scheduling information includes an aperiodic zero-power (ZP) CSI-RS indication field that is newly added to the DCI.

Optionally, in a case that the DCI is DCI of a carrier configured with an aperiodic CSI-RS, the matching module includes: a first obtaining sub-module used to obtain values of bits of a part of or all of an area in the scheduling information, where the area is used to indicate the PDSCH rate matching and includes the aperiodic ZP CSI-RS indication field; and a first matching sub-module used to perform the PDSCH rate matching based on a state corresponding to the values of the bits.

Optionally, in a case that the DCI is DCI of a carrier not configured with an aperiodic CSI-RS, the matching module includes: a second obtaining sub-module used to obtain values of bits of a part of or all of an area in the scheduling information, where the area is used to indicate the PDSCH rate matching and does not include the aperiodic ZP CSI-RS indication field; and a second matching sub-module used to perform the PDSCH rate matching based on a state corresponding to the values of the bits.

Optionally, the terminal further includes a decoding module, used to decode the DCI based on the maximum value before the matching module performs the PDSCH rate matching based on the scheduling information.

The present disclosure further provides a base station, including: a processor, and a memory and a transceiver that are connected to the processor. The memory is used to store programs and data to be used by the processor when executing operations. When calling and executing the programs and data stored in the memory, the processor performs the following processes: configuring the number of bits occupied by downlink control information (DCI) used to indicate physical downlink shared channel (PDSCH) scheduling on each of all carriers corresponding to a to-be-scheduled terminal to be N, where N is a maximum number of bits occupied by the DCI that is used to indicate the PDSCH scheduling on a carrier configured with an aperiodic channel state information reference signal (CSI-RS); and constructing scheduling information for indicating the PDSCH scheduling based on the configured DCI, and transmitting the scheduling information to the to-be-scheduled terminal. The transceiver is used to receive and transmit data under control of the processor.

The present disclosure further provides a terminal, including: a processor, and a memory and a transceiver that are connected to the processor. The memory is used to store programs and data to be used by the processor when executing operations. When calling and executing the programs and data stored in the memory, the processor performs the following processes: receiving, via the transceiver, scheduling information for indicating a physical downlink shared channel (PDSCH) scheduling transmitted by a base station, where the number of bits occupied by downlink control information (DCI) in the scheduling information is a maximum number of bits occupied by DCI that is of a carrier configured with an aperiodic channel state information reference signal (CSI-RS) and is used to indicate the PDSCH scheduling; and performing PDSCH rate matching based on the scheduling information. The transceiver is used to receive and transmit data under control of the processor.

Beneficial effects of the above technical solutions of the present disclosure are described as follows. The numbers of the bits occupied by the pieces of DCI used to indicate the PDSCH scheduling on the all carriers corresponding to the to-be-scheduled terminal are set to be N, such that the terminal only needs to obtain a size of one kind of DCI by blindly decoding the DCI no matter whether the carriers are configured with aperiodic CSI-RSs. In this way, computation complexity of the terminal is reduced; a search area for a size of each piece of DCI and flexibility of the PDSCH scheduling are ensured; and it is ensured, with the introduce of aperiodic CSI-RS, that the UE can perform PDSCH rate matching accurately and data can be transmitted correctly.

