Information transmission method, user equipment, and base station

The present invention discloses an information transmission method, user equipment, and a base station. The method includes: receiving indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal (CRS) is transmitted; determining the first downlink subframe according to the indication information; and performing information transmission according to the first downlink subframe. According to the information transmission method, the user equipment, and the base station of embodiments of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted.

TECHNICAL FIELD

The present invention relates to the communications field, and in particular, to an information transmission method, user equipment, and a base station in the communications field.

BACKGROUND

In a current Long Term Evolution (LTE) system, user equipment (UE) synchronizes with an evolved NodeB (eNB) by detecting a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) that are sent by an evolved NodeB (eNB), user equipment (UE) synchronizes with the eNB and recognizes a physical cell. Then, the UE reads a system broadcast message sent by the eNB, initiates random access to the eNB, and finally can establish a radio resource control (RRC) connection to the eNB, so that the UE can perform data communication with the eNB.

The UE in RRC_CONNECTED mode needs to perform necessary measurement and synchronization tracking to perform data communication with the eNB. For example, the UE needs to measure channel state information (CSI) by using a cell-specific reference signal (CRS) or a channel state information-reference signal (CSI-RS), so that the eNB selects a suitable modulation and coding scheme for data scheduling of the UE. For another example, the UE needs to perform synchronization tracking, that is, fine time and frequency synchronization, by using the CRS, to ensure demodulation performance of data. Still for another example, the UE further needs to perform radio resource management (RRM) measurement by using the CRS, to ensure mobility performance of the UE.

However, in the prior art, user equipment cannot know which downlink subframes are used by a base station to transmit a CRS, and therefore, performance of communication between the user equipment and the base station is severely affected.

SUMMARY

Embodiments of the present invention provide an information transmission method, user equipment, and a base station, so that the user equipment can know a downlink subframe in which a CRS is transmitted, and performance of a communications system can be improved.

According to a first aspect, an information transmission method is provided, where the method includes: receiving indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted; determining the first downlink subframe according to the indication information; and performing information transmission according to the first downlink subframe.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the receiving indication information sent by a base station includes: receiving a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe; and the determining the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the downlink control channel.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and the determining the first downlink subframe according to the downlink control channel includes: determining the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

With reference to the first possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C; and the determining the first downlink subframe according to the downlink control channel includes: determining the first downlink subframe according to the CRS indicator field.

With reference to the first aspect, in a fourth possible implementation manner of the first aspect, the receiving indication information sent by a base station includes: receiving higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe; and the determining the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the second downlink subframe.

With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation manner of the first aspect, the determining the first downlink subframe according to the second downlink subframe includes: determining the second downlink subframe as the first downlink subframe in which the CRS is transmitted.

With reference to the first aspect, in a sixth possible implementation manner of the first aspect, the receiving indication information sent by a base station includes: receiving a master information block MIB sent by the base station, where the MIB is used to indicate the first downlink subframe; and the determining the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the MIB.

With reference to the sixth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe; and the determining the first downlink subframe according to the MIB includes: determining the first downlink subframe according to the CRS indicator field included in the MIB.

According to a second aspect, an information transmission method is provided, where the method includes: determining a first downlink subframe in which a cell-specific reference signal CRS is transmitted; sending, to user equipment, indication information used to indicate the first downlink subframe; and performing information transmission according to the first downlink subframe.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the sending, to user equipment, indication information used to indicate the first downlink subframe includes: sending, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

With reference to the second aspect, in a fourth possible implementation manner of the second aspect, the sending, to user equipment, indication information used to indicate the first downlink subframe includes: sending higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

With reference to the fourth possible implementation manner of the second aspect, in a fifth possible implementation manner of the second aspect, the first downlink subframe in which the CRS is transmitted is the same as the second downlink subframe.

With reference to the second aspect, in a sixth possible implementation manner of the second aspect, the sending, to user equipment, indication information used to indicate the first downlink subframe includes: sending a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

With reference to the sixth possible implementation manner of the second aspect, in a seventh possible implementation manner of the second aspect, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

According to a third aspect, user equipment is provided, where the user equipment includes: a receiving module, configured to receive indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted; a determining module, configured to determine the first downlink subframe according to the indication information received by the receiving module; and a transmission module, configured to perform information transmission according to the first downlink subframe determined by the determining module.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the receiving module includes: a first receiving unit, configured to receive a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe; and the determining module includes: a first determining unit, configured to determine the first downlink subframe according to the downlink control channel received by the first receiving unit.

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, a cyclic redundancy check CRC code of the downlink control channel received by the first receiving unit is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and the first determining unit is specifically configured to determine the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

With reference to the first possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect, a cyclic redundancy check CRC code of the downlink control channel received by the first receiving unit is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C; and the first determining unit is specifically configured to determine the first downlink subframe according to the CRS indicator field.

With reference to the third aspect, in a fourth possible implementation manner of the third aspect, the receiving module includes: a second receiving unit, configured to receive higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe; and the determining module includes: a second determining unit, configured to determine the first downlink subframe according to the second downlink subframe indicated by the higher layer signaling received by the second receiving unit.

With reference to the fourth possible implementation manner of the third aspect, in a fifth possible implementation manner of the third aspect, the second determining unit is specifically configured to determine, as the first downlink subframe in which the CRS is transmitted, the second downlink subframe indicated by the higher layer signaling received by the second receiving unit.

With reference to the third aspect, in a sixth possible implementation manner of the third aspect, the receiving module includes: a third receiving unit, configured to receive a master information block MIB sent by the base station, where the MIB is used to indicate the first downlink subframe; and the determining module includes: a third determining unit, configured to determine the first downlink subframe according to the MIB received by the third receiving unit.

With reference to the sixth possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect, the MIB received by the third receiving unit includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe; and the third determining unit is specifically configured to determine the first downlink subframe according to the CRS indicator field included in the MIB received by the third receiving unit.

According to a fourth aspect, a base station is provided, where the base station includes: a determining module, configured to determine a first downlink subframe in which a cell-specific reference signal CRS is transmitted; a sending module, configured to send, to user equipment, indication information used to indicate the first downlink subframe determined by the determining module; and a transmission module, configured to perform information transmission according to the first downlink subframe determined by the determining module.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the sending module includes: a first sending unit, configured to send, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, a cyclic redundancy check CRC code of the downlink control channel sent by the first sending unit is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the fourth aspect, in a third possible implementation manner of the fourth aspect, a cyclic redundancy check CRC code of the downlink control channel sent by the first sending unit is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

With reference to the fourth aspect, in a fourth possible implementation manner of the fourth aspect, the sending module includes: a second sending unit, configured to send higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

With reference to the fourth possible implementation manner of the fourth aspect, in a fifth possible implementation manner of the fourth aspect, the second downlink subframe indicated by the higher layer signaling sent by the second sending unit is the same as the first downlink subframe in which the CRS is transmitted.

With reference to the fourth aspect, in a sixth possible implementation manner of the fourth aspect, the sending module includes: a third sending unit, configured to send a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

With reference to the sixth possible implementation manner of the fourth aspect, in a seventh possible implementation manner of the fourth aspect, the MIB sent by the third sending unit includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

According to a fifth aspect, user equipment is provided, and the user equipment includes a processor, a memory, a bus system, and a transceiver, where the processor, the memory and the transceiver are connected by using the bus system, the memory is configured to store an instruction, and the processor is configured to execute the instruction stored by the memory, to control the transceiver to receive a signal or send a signal; and the transceiver is configured to receive indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted; the processor is configured to determine the first downlink subframe according to the indication information; and the transceiver is further configured to perform information transmission according to the first downlink subframe.

With reference to the fifth aspect, in a first possible implementation manner of the fifth aspect, the receiving, by the transceiver, indication information sent by a base station includes: receiving a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe; and the determining, by the processor, the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the downlink control channel.

With reference to the first possible implementation manner of the fifth aspect, in a second possible implementation manner of the fifth aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and the determining, by the processor, the first downlink subframe according to the downlink control channel includes: determining the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

With reference to the first possible implementation manner of the fifth aspect, in a third possible implementation manner of the fifth aspect, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A, or a DCI format 1C; and the determining, by the processor, the first downlink subframe according to the downlink control channel includes: determining the first downlink subframe according to the CRS indicator field.

With reference to the fifth aspect, in a fourth possible implementation manner of the fifth aspect, the receiving, by the transceiver, indication information sent by a base station includes: receiving higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe; and the determining, by the processor, the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the second downlink subframe.

With reference to the fourth possible implementation manner of the fifth aspect, in a fifth possible implementation manner of the fifth aspect, the determining, by the processor, the first downlink subframe according to the second downlink subframe includes: determining the second downlink subframe as the first downlink subframe in which the CRS is transmitted.

With reference to the fifth aspect, in a sixth possible implementation manner of the fifth aspect, the receiving, by the transceiver, indication information sent by a base station includes: receiving a master information block MIB sent by the base station, where the MIB is used to indicate the first downlink subframe; and the determining, by the processor, the first downlink subframe according to the indication information includes: determining the first downlink subframe according to the MIB.

With reference to the sixth possible implementation manner of the fifth aspect, in a seventh possible implementation manner of the fifth aspect, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe; and the determining, by the processor, the first downlink subframe according to the MIB includes: determining the first downlink subframe according to the CRS indicator field included in the MIB.

According to a sixth aspect, a base station is provided, and the base station includes a processor, a memory, a bus system, and a transceiver, where the processor, the memory and the transceiver are connected by using the bus system, the memory is configured to store an instruction, and the processor is configured to execute the instruction stored by the memory, to control the transceiver to receive a signal or send a signal; and the processor is configured to determine a first downlink subframe in which a cell-specific reference signal CRS is transmitted; the transceiver is configured to send, to user equipment, indication information used to indicate the first downlink subframe; and the transceiver is further configured to perform information transmission according to the first downlink subframe.

With reference to the sixth aspect, in a first possible implementation manner of the sixth aspect, the sending, by the transceiver, to user equipment, indication information used to indicate the first downlink subframe includes: sending, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the sixth aspect, in a second possible implementation manner of the sixth aspect, a cyclic redundancy check CRC code of the downlink control channel sent by the transceiver is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

With reference to the first possible implementation manner of the sixth aspect, in a third possible implementation manner of the sixth aspect, a cyclic redundancy check CRC code of the downlink control channel sent by the transceiver is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

With reference to the sixth aspect, in a fourth possible implementation manner of the sixth aspect, the sending, by the transceiver, to user equipment, indication information used to indicate the first downlink subframe includes: sending higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

With reference to the fourth possible implementation manner of the sixth aspect, in a fifth possible implementation manner of the sixth aspect, the first downlink subframe in which the CRS is transmitted is the same as the second downlink subframe.

With reference to the sixth aspect, in a sixth possible implementation manner of the sixth aspect, the sending, by the transceiver, to user equipment, indication information used to indicate the first downlink subframe includes: sending a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

With reference to the sixth possible implementation manner of the sixth aspect, in a seventh possible implementation manner of the sixth aspect, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

Based on the foregoing technical solutions and according to the information transmission method, the user equipment, and the base station of the embodiments of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

DETAILED DESCRIPTION

It should also be understood that in the embodiments of the present invention, user equipment (UE) may be referred to as a terminal (Terminal), a mobile station (MS), a mobile terminal (Mobile Terminal), and the like. The user equipment may communicate with one or more core networks by using a radio access network (RAN). For example, the user equipment may be a mobile phone (also referred to as a “cellular” phone) or a computer with a mobile terminal. For example, the user equipment may also be a portable, pocket-sized, handheld, computer built-in, or in-vehicle mobile apparatus, which exchanges voice and/or data with the radio access network.

In the embodiments of the present invention, a base station may be a base station (BTS) in the GSM or CDMA, or may be a base station (NodeB, “NB” for short) in the WCDMA, or may be an evolved NodeB (Evolutional Node B, “eNB” or “e-NodeB” for short) in the LTE, which is not limited in the present invention. However, for ease of description, the following embodiments are described by using an eNB as an example.

FIG. 1is a schematic flowchart of an information transmission method100according to an embodiment of the present invention. The method100may be executed by a device on a user equipment side, for example, may be executed by UE. As shown inFIG. 1, the method100includes:

S110: Receive indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted,

S120: Determine the first downlink subframe according to the indication information.

S130: Perform information transmission according to the first downlink subframe.

Specifically, user equipment determines the first downlink subframe in which the cell-specific reference signal CRS is transmitted, or user equipment determines, according to the indication information, the first downlink subframe in which the cell-specific reference signal CRS is transmitted, and therefore may perform information transmission according to the first downlink subframe. For example, after determining the first downlink subframe in which the CRS is transmitted, the base station may send, to the user equipment, the indication information used to indicate the first downlink subframe; the user equipment may receive the indication information sent by the base station, so that the user equipment may determine, according to the indication information, the first downlink subframe in which the CRS is transmitted, and may perform information transmission according to the first downlink subframe, for example, transmitting a CRS, or detecting a channel to transmit a channel signal, or transmitting data.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In an LTE system, UE in an RRC_CONNECTED mode needs to perform necessary measurement and synchronization tracking to perform data communication with an eNB. To meet requirements of the foregoing measurement and synchronization, time-frequency granularity of a signal in the LTE system may be: A sending period of a PSS and an SSS is both 5 ms, and two orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, “OFDM” for short) symbols of six resource blocks at the center of a carrier are occupied for each transmission; each subframe that carries a CRS requires fullband transmission, which generally occupies two or four resource units in two OFDM symbols of one resource block; especially, for a later evolved LTE system, a non-backward compatible carrier is introduced, and a sending period of the CRS at least needs to be kept as 5 ms; as a reference signal for CSI measurement, such as a CSI-RS, a current shortest sending period is 5 ms, and an occupied resource is more sparse than that of the CRS.

It can be seen that, sending periods of some reference signals, such as the PSS, the SSS, and the CRS in the LTE system are relatively short; even if there is no UE requiring a service, the eNB still needs to send the foregoing reference signals, and therefore, power efficiency of the eNB is not very high. On the other hand, even if there is no UE requiring a service, because the eNB needs to send the CRS in each subframe, the sent CRS still causes interference to data communication of another cell, affecting system performance of the another cell.

To improve the power efficiency of the eNB and reduce interference between cells, a dynamic base-station discontinuous transmission (DTX) technology may be introduced in a later evolved system. In the technology, a signal may not be sent in any downlink subframe in a cell, but the following restrictions need to be satisfied:

(1) if a transmission mode (transmission modes1to10) is configured for one or more UEs in UEs served by the cell, then a PSS/SSS/CRS is sent according to a rule in LTE version 8 to LTE version 11, that is, the PSS/SSS is sent in a period of 5 ms, and the CRS is sent in each subframe; and

(2) if a transmission mode x is configured for one or more UEs in UEs served by the cell, and the transmission mode x is an enhanced transmission mode and is a transmission mode other than transmission modes1to10, only a downlink subframe0and a downlink subframe5certainly transmit the CRS, and whether the CRS is transmitted in other downlink subframes is not limited.

In the foregoing DTX technology, for user equipment UE for which the transmission mode x is configured, the UE can clearly know only that the downlink subframe0and the downlink subframe5transmit the CRS, but cannot know whether the CRS is transmitted in other downlink subframes. However, whether the CRS is transmitted in a downlink subframe has great impact on information transmission between user equipment and a base station, for example, has impact on channel detection, channel information measurement, and the like performed by the user equipment, for example, has impact on detection of a physical downlink shared channel (PDSCH), detection of a physical downlink control channel (PDCCH), detection of an enhanced physical downlink control channel (EPDCCH), detection of a physical hybrid automatic repeat request indicator channel (PHICH, where a hybrid automatic repeat request (Hybrid Automatic Repeat Request) is referred to “HARQ” for short), and the like. For another example, if the CRS is transmitted in a downlink subframe, but when decoding a PDSCH, the user equipment considers that no CRS is transmitted, and performs detection by considering the CRS signal as a PDSCH signal, which therefore causes that the user equipment cannot correctly receive the PDSCH, thereby greatly affecting performance of data communication between the user equipment and the base station.

In this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved. For example, the user equipment can correctly perform channel detection and channel information measurement according to the downlink subframe in which the CRS is transmitted; for another example, the user equipment can correctly detect a channel such as a PDSCH, a PDCCH, an EPDCCH, and a PHICH according to the downlink subframe in which the CRS is transmitted, so that the user equipment can correctly receive data of the base station, can also correctly send data to the base station, and therefore can correctly communicate with the base station. In this way, performance of a communications system can be improved.

The information transmission method according to this embodiment of the present invention is described in detail below with reference toFIG. 2toFIG. 4.

As shown inFIG. 2, in this embodiment of the present invention, optionally, the receiving indication information sent by a base station includes:

S111: Receive a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

The determining the first downlink subframe according to the indication information includes:

S121: Determine the first downlink subframe according to the downlink control channel.

Specifically, in S111, user equipment receives the downlink control channel sent by the base station, the downlink control channel is carried in the downlink subframe0and/or the downlink subframe5, and the downlink control channel is used to indicate the first downlink subframe. That is, the downlink control channel may include the indication information used to indicate the first downlink subframe, or the downlink control channel itself is the indication information that is used by the base station to indicate the first downlink subframe to the user equipment, but this embodiment of the present invention is not limited thereto.

It should be understood that, in this embodiment of the present invention, the downlink control channel is a type of resource that is used to transmit information of a control plane. A downlink subframe may carry resource indication information used to indicate a resource, that is, the receiving a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5may be understood as: receiving resource indication information that is sent by the base station and that is used to indicate the downlink control channel, where the resource indication information is carried in the downlink subframe0and/or the downlink subframe5.

In S121, the user equipment may determine, according to the downlink control channel, the first downlink subframe in which the CRS is transmitted.

That is, in this embodiment of the present invention, the user equipment receives the downlink control channel carried in the downlink subframe0and/or the downlink subframe5, and may determine, according to the downlink control channel, the first downlink subframe in which the cell-specific reference signal CRS is transmitted, so that the user equipment may perform information transmission according to the first downlink subframe.

That is, in this embodiment of the present invention, the indication information used to indicate the first downlink subframe in which the CRS is transmitted is a downlink control channel, and the user equipment may determine, according to the downlink control channel, the first downlink subframe in which the CRS is transmitted.

It should be understood that, in this embodiment of the present invention, the first downlink subframe represents one or more downlink subframes in which the cell-specific reference signal CRS is transmitted. It should further be understood that, in this embodiment of the present invention, the first downlink subframe determined by the user equipment according to the indication information may include the downlink subframe0and the downlink subframe5in which the CRS is transmitted, or may not include the downlink subframe0and the downlink subframe5. In addition, the first downlink subframe may further include a downlink subframe in a radio subframe except the downlink subframe0and the downlink subframe5, where the CRS is transmitted in the downlink subframe. This embodiment of the present invention is not limited thereto.

It should further be understood that, this embodiment of the present invention only uses the DTX technology as an example for description, but the present invention is not limited thereto. The information transmission method based on this embodiment of the present invention may also be applied to another technology, so that the user equipment can know the downlink subframe in which the CRS is transmitted, can also know whether the CRS is transmitted in each downlink subframe, and can correctly communicate with the base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In this embodiment of the present invention, a downlink control information (DCI) format used by the downlink control channel may be used to indicate the first downlink subframe. For example, a hybrid automatic repeat request (HARQ) field in the DCI format may be used to indicate the first downlink subframe, and another field in the DCI format may also be used to indicate the first downlink subframe. For example, the DCI format may include a CRS indicator field used to indicate the first downlink subframe.

Optionally, in this embodiment of the present invention, a cyclic redundancy check (CRC) code of the downlink control channel is scrambled by using a first radio network temporary identifier (RNTI), where the first RNTI includes at least one of a random access RNTI (RA-RNTI), a paging RNTI (Paging RNTI, “P-RNTI” for short), and a system information RNTI (System Information RNTI, “SI-RNTI” for short), and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and

the determining the first downlink subframe according to the downlink control channel includes:

determining the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

Specifically, in this embodiment of the present invention, the downlink control channel may be a PDCCH, or may be an EPDCCH; the first DCI format used by the downlink control channel may be the DCI format 1A, and the HARQ process number field in the DCI format 1A may be used to indicate the first downlink subframe in which the CRS is transmitted. Therefore, the user equipment may determine, according to the HARQ process number field included in the DCI format 1A used by the received downlink control channel, the first downlink subframe in which the CRS is transmitted. Specifically, the user equipment may determine, according to the HARQ process number field included in the DCI format 1A used by the received downlink control channel and a preset correspondence between a value of the HARQ process number field and a downlink subframe in which the CRS is transmitted, the first downlink subframe in which the CRS is transmitted.

For example, the preset correspondence between a value of the HARQ process number field and a downlink subframe in which the CRS is transmitted may be shown in Table 1, and the user equipment may determine, according to a value ‘100’ of the HARQ process number field, that the first downlink subframe in which the CRS is transmitted is a downlink subframe1and a downlink subframe6. For another example, the user equipment may determine, according to a value ‘110’ of the HARQ process number field, that the first downlink subframe in which the CRS is transmitted is a downlink subframe1, a downlink subframe2, a downlink subframe6, and a downlink subframe7. For still another example, the user equipment may determine, according to a value ‘111’ of the HARQ process number field, that the first downlink subframe in which the CRS is transmitted is all downlink subframes.

It should be understood that, this embodiment of the present invention is described by using the correspondence shown in Table 1 as an example only, but the present invention is not limited thereto. For example, a value ‘100’ of the HARQ process number field may also be used to indicate that the downlink subframe in which the CRS is transmitted is a downlink subframe1.

In this embodiment of the present invention, after determining the first downlink subframe in which the CRS is transmitted, the user equipment may perform information transmission according to the determined first downlink subframe, for example, transmitting a CRS, or detecting a channel to transmit a channel signal, or transmitting data.

For example, in the downlink subframe in which the CRS is transmitted, the user equipment performs information transmission based on the assumption that a CRS has been transmitted. For example, the user equipment may detect, in the downlink subframe in which the CRS is transmitted, PDCCH common search space (CSS). For another example, the user equipment detects a PHICH only in the downlink subframe in which the CRS is transmitted. For still another example, in the downlink subframe in which the CRS is transmitted, the user equipment performs EPDCCH detection or performs PDCCH detection or the like based on the assumption that a CRS has been transmitted.

For example, for a downlink subframe in which no CRS is transmitted, the user equipment performs information transmission based on the assumption that no CRS has been transmitted. For example, for a downlink subframe in which no CRS is transmitted, the user equipment does not need to detect PDCCH CSS. For another example, for a downlink subframe in which no CRS is transmitted, the user equipment does not need to detect a PHICH. For still another example, for a downlink subframe in which no CRS is transmitted, the user equipment performs EPDCCH detection or performs PDCCH detection or the like based on the assumption that no CRS has been transmitted.

That is, in this embodiment of the present invention, the user equipment receives the downlink control channel whose CRC code is scrambled by using the first RNTI, the downlink control channel is carried in the downlink subframe0and/or the downlink subframe5, the downlink control channel is a PDCCH or an EPDCCH, the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and the first downlink control information DCI format used by the downlink control channel is the DCI format 1A. The user equipment determines the first downlink subframe according to the hybrid automatic repeat request HARQ process number field in the DCI format 1A, so that the user equipment may perform information transmission according to the first downlink subframe.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, a reserved bit in the DCI format 1A for indicating public message sending is reused to indicate the first downlink subframe in which the CRS is transmitted. On the one hand, a problem of how to indicate, to UE, a first downlink subframe in which a CRS is transmitted is resolved; on the other hand, because no new indication signaling needs to be introduced in the method, standard complexity can be reduced and system resources can be saved.

In this embodiment of the present invention, optionally, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C; and

the determining the first downlink subframe according to the downlink control channel includes:

determining the first downlink subframe according to the CRS indicator field.

Specifically, in this embodiment of the present invention, the downlink control channel may be a PDCCH, or may be an EPDCCH, and the second RNTI for scrambling the CRC code is used to indicate that the downlink control channel carries the information that indicates the first downlink subframe; in addition, the second DCI format used by the downlink control channel includes the CRS indicator field used to indicate the first downlink subframe, and the size of the second DCI format may be the same as the size of the DCI format 1A or the DCI format 1C, so as to reduce standard complexity. Therefore, the user equipment may determine, according to the CRS indicator field included in the second DCI format used by the received downlink control channel, the first downlink subframe in which the CRS is transmitted. Specifically, the user equipment may determine, according to the CRS indicator field and a correspondence between a value of the CRS indicator field and a downlink subframe in which the CRS is transmitted, the first downlink subframe in which the CRS is transmitted.

For example, as shown in Table 2, the user equipment may determine, according to a value ‘0000’ of the CRS indicator field, a downlink subframe in which no CRS is transmitted; for another example, the user equipment may determine, according to a value ‘0001’ of the CRS indicator field, that the first downlink subframe in which the CRS is transmitted is a downlink subframe1or a downlink subframe6; for still another example, the user equipment may determine, according to a value ‘ 0011’ of the CRS indicator field, that the first downlink subframe in which the CRS is transmitted is a downlink subframe1and a downlink subframe2, or may determine that the first downlink subframe in which the CRS is transmitted is a downlink subframe6and a downlink subframe7, or the like.

It should be understood that, this embodiment of the present invention is described by using the correspondence shown in Table 2 as an example only, but the present invention is not limited thereto. For example, a value ‘0001’ of the HARQ process number field may also be used to indicate that the downlink subframe in which the CRS is transmitted is a downlink subframe2or a downlink subframe7.

In this embodiment of the present invention, after determining the first downlink subframe in which the CRS is transmitted, the user equipment may perform information transmission according to the determined first downlink subframe, for example, transmitting a CRS, or detecting a channel to transmit a channel signal, or transmitting data.

That is, in this embodiment of the present invention, the user equipment receives the downlink control channel whose CRC code is scrambled by using the second RNTI, the downlink control channel is carried in a downlink subframe0and/or a downlink subframe5, the downlink control channel is a PDCCH or an EPDCCH, the second RNTI is used to indicate that the downlink control channel carries the information that indicates the first downlink subframe, the second downlink control information DCI format used by the downlink control channel includes the CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and the size of the second DCI format is the same as the size of the DCI format 1A or the DCI format 1C; the user equipment determines the first downlink subframe according to the CRS indicator field, so that the user equipment may perform information transmission according to the first downlink subframe.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

It should be understood that, in this embodiment of the present invention, the downlink control channel used to indicate the first downlink subframe may be carried in the downlink subframe0and/or the downlink subframe5, so as to reduce standard complexity, but the present invention is not limited thereto; the downlink control channel used to indicate the first downlink subframe may also be carried in another downlink subframe except the downlink subframe0and the downlink subframe5.

It should further be understood that, in this embodiment of the present invention, that the DCI format used by the downlink control channel indicates the first downlink subframe is merely used as an example for description, but the present invention is not limited thereto, for example, other information related to the downlink control channel may also be used for the first downlink subframe, or the downlink control channel may include indication information used to indicate the first downlink subframe.

In this embodiment of the present invention, optionally, as shown inFIG. 3, the receiving indication information sent by a base station includes:

S112: Receive higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

The determining the first downlink subframe according to the indication information includes:

S122: Determine the first downlink subframe according to the second downlink subframe.

Specifically, the user equipment may learn, according to the received higher layer signaling, the second downlink subframe in which the common search space of the PDCCH is transmitted, and therefore determines the first downlink subframe according to an association relationship between the second downlink subframe and the first downlink subframe in which the CRS is transmitted.

In this embodiment of the present invention, the user equipment may determine a part of downlink subframes in the second downlink subframe as the first downlink subframe. For example, the user equipment may determine a downlink subframe having a smallest sequence number in the second downlink subframe as the first downlink subframe in which the CRS is transmitted; or the user equipment may determine a downlink subframe having a largest sequence number in the second downlink subframe as the first downlink subframe in which the CRS is transmitted; or the like.

In this embodiment of the present invention, the user equipment may determine all of downlink subframes in the second downlink subframe as the first downlink subframe. That is, optionally, the determining the first downlink subframe according to the second downlink subframe includes: determining the second downlink subframe as the first downlink subframe in which the CRS is transmitted.

That is, in this embodiment of the present invention, the user equipment receives higher layer signaling, where the higher layer signaling indicates a second downlink subframe in which common search space of a physical downlink control channel PDCCH is transmitted; and may determine, according to the second downlink subframe, the first downlink subframe in which the cell-specific reference signal CRS is transmitted. Optionally, the user equipment determines the second downlink subframe as the first downlink subframe in which the cell-specific reference signal CRS is transmitted.

That is, in this embodiment of the present invention, the indication information used to indicate the first downlink subframe in which the CRS is transmitted is higher layer signaling, more specifically, the indication information is a second downlink subframe indicated by the higher layer signaling, and therefore the user equipment may determine, according to the second downlink subframe, the first downlink subframe in which the CRS is transmitted.

Optionally, when the user equipment determines, according to the second downlink subframe in which the common search space of the PDCCH is transmitted, the first downlink subframe in which the CRS is transmitted, step S110may also be receiving indication information sent by a base station; step S120may also be determining, according to the indication information, the first downlink subframe in which the CRS is transmitted; step S130may still be performing information transmission according to the first downlink subframe. In this case, step S112may be: receiving higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe in which common search space of a physical downlink control channel PDCCH is transmitted; step S122may be determining, according to the second downlink subframe, the first downlink subframe in which the CRS is transmitted, and may be specifically that the user equipment determines the second downlink subframe as the first downlink subframe in which the cell-specific reference signal CRS is transmitted.

It should further be understood that, in this embodiment of the present invention, the user equipment may determine, according to an association relationship or a correspondence between the second downlink subframe and the first downlink subframe in which the CRS is transmitted, a downlink subframe that does not belong to the second downlink subframe as the first downlink subframe, but the present invention is not limited thereto.

It should be understood that, in this embodiment of the present invention, “first” and “second” are merely used to distinguish different objects, but are not intended to limit the scope of this embodiment of the present invention. For example, the first downlink subframe represents one or more downlink subframes in which the CRS is transmitted, and the second downlink subframe represents one or more downlink subframes used to transmit common search space of a physical downlink control channel PDCCH, but the present invention is not limited thereto.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

Besides, in the information transmission method of this embodiment of the present invention, the first downlink subframe in which the CRS is transmitted is associated with the second downlink subframe in which the PDCCH CSS is transmitted. One the one hand, a problem of how to indicate, to UE, a first downlink subframe in which a CRS is transmitted is resolved; one the other hand, because no new indication signaling needs to be introduced in the method, standard complexity can be reduced and system resources can be saved.

As shown inFIG. 4, in this embodiment of the present invention, optionally, the receiving indication information sent by a base station includes:

S113: Receive a master information block (MIB) sent by the base station, where the MIB is used to indicate the first downlink subframe.

The determining the first downlink subframe according to the indication information includes:

S123: Determine the first downlink subframe according to the MIB.

Specifically, in S113, the user equipment may receive a broadcast channel, so as to receive the MIB carried on the broadcast channel, where the MIB may include information used to indicate the first downlink subframe in which the CRS is transmitted. For example, the broadcast channel may be a physical broadcast channel (PBCH). In S123, the user equipment may determine the first downlink subframe according to the received MIB.

In this embodiment of the present invention, optionally, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

The determining the first downlink subframe according to the MIB includes:

determining the first downlink subframe according to the CRS indicator field included in the MIB.

For example, the MIB may include a downlink transmission bandwidth indicator field of three bits, a physical hybrid automatic repeat request indicator channel PHICH configuration information indicator field of three bits, a system frame number indicator field of eight bits, and a CRS indicator field of ten bits, and the user equipment may determine, according to a value of the CRS indicator field, the first downlink subframe in which the CRS is transmitted. Specifically, the user equipment may determine, according to the CRS indicator field and a correspondence between a value of the CRS indicator field and a downlink subframe in which the CRS is transmitted, the first downlink subframe in which the CRS is transmitted.

It should be understood that, in this embodiment of the present invention, the MIB may include the CRS indicator field used to indicate the first downlink subframe, the user equipment may determine the first downlink subframe according to the CRS indicator field, where a size of the CRS indicator field may be of another value, for example, the size of the CRS indicator field may be four bits, six bits, eight bits, or the like, and this embodiment of the present invention is not limited thereto.

In this embodiment of the present invention, optionally, the determining the first downlink subframe according to the MIB includes: determining the first downlink subframe according to the PHICH configuration information indicator field included in the MIB.

For example, the MIB may include a physical hybrid automatic repeat request indicator channel PHICH configuration information indicator field of three bits, and the user equipment may determine, according to the PHICH configuration information indicator field and a correspondence between a value of the PHICH configuration information indicator field and a downlink subframe in which the CRS is transmitted, the first downlink subframe in which the CRS is transmitted.

For example, as shown in Table 3, the user equipment may determine, according to a value ⅙ of the PHICH configuration information indicator field, that the first downlink subframe in which the CRS is transmitted is all downlink subframes; for another example, the user equipment may determine, according to a value 2 of the PHICH configuration information indicator field, that the first downlink subframe in which the CRS is transmitted is a downlink subframe1or a downlink subframe6.

That is, in this embodiment of the present invention, the user equipment receives the master information block MIB, and may determine, according to the MIB, the first downlink subframe in which the cell-specific reference signal CRS is transmitted, so that the user equipment may perform information transmission according to the first downlink subframe. For example, the user equipment may determine, according to the CRS indicator field that is included in the MIB and that is used to indicate the first downlink subframe in which the cell-specific reference signal CRS is transmitted, the first downlink subframe in which the cell-specific reference signal CRS is transmitted; the user equipment may also determine, according to the PHICH configuration information indicator field, the first downlink subframe in which the cell-specific reference signal CRS is transmitted.

That is, in this embodiment of the present invention, the indication information used to indicate the first downlink subframe in which the CRS is transmitted is a master information block MIB, and therefore the user equipment may determine, according to the MIB, the first downlink subframe in which the CRS is transmitted.

It should be understood that, in this embodiment of the present invention, that the CRS indicator field or the PHICH configuration information indicator field included in the MIB indicates the first downlink subframe is merely used as an example for description, but the present invention is not limited thereto. Another field included in the MIB may also be used to indicate the first downlink subframe.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, a reserved field or PHICH configuration information indicator field in an MIB is reused to indicate the first downlink subframe in which the CRS is transmitted. On the one hand, a problem of how to indicate, to UE, a first downlink subframe in which a CRS is transmitted is resolved; on the other hand, because no new indication signaling needs to be introduced in the method, standard complexity can be reduced and system resources can be saved.

The information transmission method of the embodiments of the present invention is described in detail above from the perspective of user equipment with reference toFIG. 1toFIG. 4, and the information transmission method of the embodiments of the present invention is described in detail below from the perspective of a base station with reference toFIG. 5andFIG. 6.

As shown inFIG. 5, an information transmission method300of an embodiment of the present invention includes:

S310: Determine a first downlink subframe in which a cell-specific reference signal CRS is transmitted,

S320: Send, to user equipment, indication information used to indicate the first downlink subframe.

S330: Perform information transmission according to the first downlink subframe.

That is, in this embodiment of the present invention, a base station sends indication information to the user equipment, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted, and therefore the base station may perform information transmission according to the first downlink subframe.

Specifically, to enable the user equipment to know whether the CRS is transmitted in a downlink subframe, so as to enable the user equipment to correctly communicate with the base station, after determining the first downlink subframe in which the CRS is transmitted, the base station may use many manners to indicate the first downlink subframe to the user equipment. For example, the base station may send a downlink control channel to the user equipment, where the downlink control channel is used to indicate the first downlink subframe; the base station may also send higher layer signaling to the user equipment, so as to indicate the first downlink subframe to the user equipment; the base station may also send a broadcast channel to the user equipment, where the broadcast channel may carry indication information used to indicate the first downlink subframe. After determining the first downlink subframe in which the CRS is transmitted, the base station may perform information transmission according to the first downlink subframe, for example, the base station may transmit the CRS according to the first downlink subframe; the base station may also transmit a channel according to the first downlink subframe, for example, transmit a channel such as a PDSCH, a PDCCH, an EPDCCH, a PHICH, or the like; the base station may also transmit other information with the user equipment according to the first downlink subframe, but the present invention is not limited thereto.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

In this embodiment of the present invention, after determining the first downlink subframe in which the CRS is transmitted, the base station may use many manners to indicate the first downlink subframe to the user equipment, and details are described below with reference toFIG. 6.

In this embodiment of the present invention, optionally, as shown inFIG. 6, the sending, to user equipment, indication information used to indicate the first downlink subframe includes:

S321: Send, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

That is, the base station sends a downlink control channel to the user equipment to indicate the first downlink subframe in which the CRS is transmitted, the downlink control channel may include the indication information used to indicate the first downlink subframe, or the downlink control channel itself is the indication information that is used by the base station to indicate the first downlink subframe to the user equipment, but the present invention is not limited thereto.

That is, in this embodiment of the present invention, the base station sends a downlink control channel to the user equipment, where the downlink control channel is carried in a downlink subframe0and/or a downlink subframe5, and the downlink control channel is used to indicate the first downlink subframe in which the cell-specific reference signal CRS is transmitted, so that the base station may perform information transmission according to the first downlink subframe.

Specifically, in this embodiment of the present invention, optionally, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

In this embodiment of the present invention, the downlink control channel may be a PDCCH, or may be an EPDCCH, and a downlink control information (DCI) format used by the downlink control channel may be used to indicate the first downlink subframe. For example, a hybrid automatic repeat request (HARQ) field in the DCI format may be used to indicate the first downlink subframe, and another field in the DCI format may also be used to indicate the first downlink subframe, for example, the DCI format may include a CRS indicator field used to indicate the first downlink subframe.

Optionally, in this embodiment of the present invention, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

It should be understood that, in this embodiment of the present invention, the downlink control channel used to indicate the first downlink subframe may be carried in the downlink subframe0and/or the downlink subframe5, so as to reduce standard complexity, but the present invention is not limited thereto; the downlink control channel used to indicate the first downlink subframe may also be carried in another downlink subframe except the downlink subframe0and the downlink subframe5.

It should further be understood that, in this embodiment of the present invention, that the DCI format used by the downlink control channel indicates the first downlink subframe is merely used as an example for description, but the present invention is not limited thereto, for example, other information related to the downlink control channel may also be used for the first downlink subframe, or the downlink control channel may include indication information used to indicate the first downlink subframe.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

In this embodiment of the present invention, optionally, as shown inFIG. 6, the sending, to user equipment, indication information used to indicate the first downlink subframe includes:

S322: Send higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

Specifically, the base station may send higher layer signaling to the user equipment, where a second downlink subframe indicated by the higher layer signaling may further be used to indicate the first downlink subframe in which the CRS is transmitted. The first downlink subframe may be a part of downlink subframes in the second downlink subframe, or may be all downlink subframes in the second downlink subframe, or may include a downlink subframe that does not belong to the second downlink subframe, but the present invention is not limited thereto.

Optionally, the first downlink subframe in which the CRS is transmitted is the same as the second downlink subframe.

However, it should be understood that, in this embodiment of the present invention, the base station may use, according to an association relationship or a correspondence between the second downlink subframe and the first downlink subframe in which the CRS is transmitted, the second downlink subframe to indicate the first downlink subframe in which the CRS is transmitted, but the present invention is not limited thereto.

That is, in this embodiment of the present invention, the base station sends higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe in which common search space of a physical downlink control channel PDCCH is transmitted; therefore, the user equipment may determine, according to the second downlink subframe, the first downlink subframe in which the cell-specific reference signal CRS is transmitted. Optionally, the user equipment determines the second downlink subframe as the first downlink subframe in which the cell-specific reference signal CRS is transmitted. Therefore, the base station may perform information transmission according to the first downlink subframe.

Optionally, in this embodiment of the present invention, as shown inFIG. 6, the sending, to user equipment, indication information used to indicate the first downlink subframe includes:

S323: Send a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

Specifically, the base station may send a broadcast channel to the user equipment, where the broadcast channel may carry the MIB, and the MIB is used to indicate the first downlink subframe. For example, the MIB may include a CRS indicator field of ten bits used to indicate the first downlink subframe, and another field included in the MIB may also be used to indicate the first downlink subframe. For example, the MIB may include a downlink transmission bandwidth indicator field of three bits, a physical hybrid automatic repeat request indicator channel PHICH configuration information indicator field of three bits, a system frame number indicator field of eight bits, and a CRS indicator field of ten bits, where the CRS indicator field is used to indicate the first downlink subframe.

In this embodiment of the present invention, optionally, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

It should be understood that, in this embodiment of the present invention, the MIB may include the CRS indicator field used to indicate the first downlink subframe, and the CRS indicator field may be used to indicate the first downlink subframe, where a size of the CRS indicator field may be of another value, for example, the size of the CRS indicator field may be four bits, six bits, eight bits, or the like, and this embodiment of the present invention is not limited thereto.

In this embodiment of the present invention, optionally, the PHICH configuration information indicator field included in the MIB is used to indicate the first downlink subframe.

For example, the MIB may include a downlink transmission bandwidth indicator field of three bits, a physical hybrid automatic repeat request indicator channel PHICH configuration information indicator field of three bits, and a system frame number indicator field of eight bits, where the PHICH configuration information indicator field is used to indicate the first downlink subframe.

That is, in this embodiment of the present invention, the base station sends the master information block MIB to the user equipment, and therefore the user equipment determines, according to the MIB, the first downlink subframe in which the cell-specific reference signal CRS is transmitted. Optionally, the user equipment may determine, according to the CRS indicator field that is included in the MIB and that is used to indicate the first downlink subframe in which the cell-specific reference signal CRS is transmitted, the first downlink subframe in which the cell-specific reference signal CRS is transmitted; the user equipment may also determine, according to the PHICH configuration information indicator field, the first downlink subframe in which the cell-specific reference signal CRS is transmitted. Therefore, the base station may perform information transmission according to the first downlink subframe.

It should be understood that, in this embodiment of the present invention, that the CRS indicator field or the PHICH configuration information indicator field included in the MIB indicates the first downlink subframe is merely used as an example for description, but the present invention is not limited thereto. Another field included in the MIB may also be used to indicate the first downlink subframe.

It should be understood that, in this embodiment of the present invention, the first downlink subframe indicated by the base station to the user equipment may include the downlink subframe0and the downlink subframe5in which the CRS is transmitted in the DTX technology, or may include a downlink subframe in a radio subframe except the downlink subframe0and the downlink subframe5, where the CRS is transmitted in the downlink subframe. This embodiment of the present invention is not limited thereto.

It should further be understood that, this embodiment of the present invention only uses the DTX technology as an example for description, but the present invention is not limited thereto. The information transmission method based on this embodiment of the present invention may also be applied to another technology, so that the user equipment can know whether the CRS is transmitted in a downlink subframe, and can correctly communicate with the base station. In this way, performance of a communications system can be improved.

Therefore, in the information transmission method of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the information transmission method of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

The information transmission method of the embodiments of the present invention is described in detail above with reference toFIG. 1toFIG. 6, and user equipment and a base station of the embodiments of the present invention are described in detail below with reference toFIG. 7andFIG. 14.

As shown inFIG. 7, user equipment500of an embodiment of the present invention includes:

a receiving module510, configured to receive indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted;

a determining module520, configured to determine the first downlink subframe according to the indication information received by the receiving module510; and

a transmission module530, configured to perform information transmission according to the first downlink subframe determined by the determining module520.

Therefore, in the user equipment of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that the user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the user equipment of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

In this embodiment of the present invention, optionally, as shown inFIG. 8, the receiving module510includes:

a first receiving unit511, configured to receive a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe; and

the determining module520includes:

a first determining unit521, configured to determine the first downlink subframe according to the downlink control channel received by the first receiving unit511.

Optionally, in this embodiment of the present invention, a cyclic redundancy check CRC code of the downlink control channel received by the first receiving unit511is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and

the first determining unit521is specifically configured to determine the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

Optionally, in this embodiment of the present invention, a cyclic redundancy check CRC code of the downlink control channel received by the first receiving unit511is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C; and

the first determining unit521is specifically configured to determine the first downlink subframe according to the CRS indicator field.

In this embodiment of the present invention, optionally, as shown inFIG. 9, the receiving module510includes:

a second receiving unit512, configured to receive higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe; and

the determining module520includes:

a second determining unit522, configured to determine the first downlink subframe according to the second downlink subframe indicated by the higher layer signaling received by the second receiving unit512.

Optionally, the second determining unit522is specifically configured to determine, as the first downlink subframe in which the CRS is transmitted, the second downlink subframe indicated by the higher layer signaling received by the second receiving unit512.

In this embodiment of the present invention, optionally, as shown inFIG. 10, the receiving module510includes:

a third receiving unit513, configured to receive a master information block MIB sent by the base station, where the MIB is used to indicate the first downlink subframe; and

the determining module520includes:

a third determining unit523, configured to determine the first downlink subframe according to the MIB received by the third receiving unit513.

Optionally, the MIB received by the third receiving unit513includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe; and

the third determining unit523is specifically configured to determine the first downlink subframe according to the CRS indicator field included in the MIB received by the third receiving unit.

The user equipment500according to this embodiment of the present invention may correspond to the user equipment in the embodiments of the present invention, the foregoing and other operations and/or functions of the modules in the user equipment500are for implementing corresponding procedures in the methods inFIG. 1toFIG. 6, and for convenience, details are not described herein again.

Therefore, in the user equipment of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that the user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the user equipment of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

FIG. 11is a schematic block diagram of a base station700according to an embodiment of the present invention. As shown inFIG. 11, the base station700includes:

a determining module710, configured to determine a first downlink subframe in which a cell-specific reference signal CRS is transmitted;

a sending module720, configured to send, to user equipment, indication information used to indicate the first downlink subframe determined by the determining module710; and

a transmission module730, configured to perform information transmission according to the first downlink subframe determined by the determining module710.

Therefore, in the base station of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with the base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the base station of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

In this embodiment of the present invention, optionally, as shown inFIG. 12, the sending module720includes:

a first sending unit721, configured to send, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

Optionally, a cyclic redundancy check CRC code of the downlink control channel sent by the first sending unit721is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

Optionally, a cyclic redundancy check CRC code of the downlink control channel sent by the first sending unit721is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

In this embodiment of the present invention, optionally, as shown inFIG. 12, the sending module720includes:

a second sending unit722, configured to send higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

Optionally, the second downlink subframe indicated by the higher layer signaling sent by the second sending unit722is the same as the first downlink subframe in which the CRS is transmitted.

In this embodiment of the present invention, optionally, as shown inFIG. 12, the sending module720includes:

a third sending unit723, configured to send a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

Optionally, the MIB sent by the third sending unit723includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

The base station700according to this embodiment of the present invention may correspond to the base station in the embodiments of the present invention, the foregoing and other operations and/or functions of the modules in the base station700are for implementing corresponding procedures in the methods inFIG. 1toFIG. 6, and for convenience, details are not described herein again.

Therefore, in the base station of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with the base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the base station of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

It should be understood that, in this embodiment of the present invention, “B corresponding to A” represents that B is associated with A, and B may be determined according to A. However, it should further be understood that, determining B according to A does not mean that B is determined according to A only, but B may also be determined according to A and/or other information.

As shown inFIG. 13, an embodiment of the present invention further provides user equipment800. The user equipment800includes a processor810, a memory820, a bus system830, and a transceiver840. The processor810, the memory820and the transceiver840are connected by using the bus system830, the memory820is configured to store an instruction, and the processor810is configured to execute the instruction stored by the memory820, to control the transceiver840to receive a signal or send a signal. The transceiver840is configured to receive indication information sent by a base station, where the indication information is used to indicate a first downlink subframe in which a cell-specific reference signal CRS is transmitted; the processor810is configured to determine the first downlink subframe according to the indication information; and the transceiver840is further configured to perform information transmission according to the first downlink subframe.

Therefore, in the user equipment of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that the user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the user equipment of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

It should be understood that in the embodiment of the present invention, the processor810may be a central processing unit (CPU), or the processor810may be another general purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or another programmable logical device, discrete gate or transistor logical device, discrete hardware component, or the like. The general purpose processor may be a microprocessor or the processor may be any conventional processor and the like.

The memory820may include a read-only memory and a random access memory, and provides an instruction and data to the processor810. A part of the memory820may further include a non-volatile random access memory. For example, the memory820may further store device type information.

The bus system830may include a power bus, a control bus, a status signal bus, and the like in addition to a data bus. However, for clear description, various types of buses in the figure are marked as the bus system830.

In an implementation process, steps in the foregoing methods may be completed by using an integrated logic circuit in a form of hardware or an instruction in a form of software in the processor810. The steps of the methods disclosed in the embodiments of the present invention may be directly completed and performed by a hardware processor, or be completed and performed by combination of hardware and software modules in a processor. The software modules may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electronically erasable programmable memory, or a register. The storage medium is located in the memory820. The processor810reads information in the memory820, and completes the steps of the foregoing methods by combining using of the hardware of the processor810. To avoid repetition, details are not described herein again.

Optionally, as an embodiment, the receiving, by the transceiver840, indication information sent by a base station includes:

receiving a downlink control channel that is sent by the base station and that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe; and

the determining, by the processor810, the first downlink subframe according to the indication information includes:

determining the first downlink subframe according to the downlink control channel.

Optionally, as an embodiment, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, and a first downlink control information DCI format used by the downlink control channel is a DCI format 1A; and

the determining, by the processor810, the first downlink subframe according to the downlink control channel includes:

determining the first downlink subframe according to a hybrid automatic repeat request HARQ process number field in the DCI format 1A.

Optionally, as an embodiment, a cyclic redundancy check CRC code of the downlink control channel is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C; and

the determining, by the processor810, the first downlink subframe according to the downlink control channel includes:

determining the first downlink subframe according to the CRS indicator field.

Optionally, as an embodiment, the receiving, by the transceiver840, indication information sent by a base station includes:

receiving higher layer signaling sent by the base station, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe; and

the determining, by the processor810, the first downlink subframe according to the indication information includes:

determining the first downlink subframe according to the second downlink subframe.

Optionally, as an embodiment, the determining, by the processor810, the first downlink subframe according to the second downlink subframe includes:

determining the second downlink subframe as the first downlink subframe in which the CRS is transmitted.

Optionally, as an embodiment, the receiving, by the transceiver840, indication information sent by a base station includes:

receiving a master information block MIB sent by the base station, where the MIB is used to indicate the first downlink subframe; and

the determining, by the processor810, the first downlink subframe according to the indication information includes:

determining the first downlink subframe according to the MIB.

Optionally, as an embodiment, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe; and

the determining, by the processor810, the first downlink subframe according to the MIB includes:

determining the first downlink subframe according to the CRS indicator field included in the MIB.

The user equipment800according to this embodiment of the present invention may correspond to an execution body that executes the method of the embodiments of the present invention and the user equipment500, the foregoing and other operations and/or functions of the modules in the user equipment800are for implementing corresponding procedures in the methods inFIG. 1toFIG. 6, and for convenience, details are not described herein again.

Therefore, in the user equipment of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that the user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with a base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the user equipment of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

As shown inFIG. 14, an embodiment of the present invention further provides a base station900. The base station900includes a processor910, a memory920, a bus system930, and a transceiver940. The processor910, the memory920and the transceiver940are connected by using the bus system930, the memory920is configured to store an instruction, and the processor910is configured to execute the instruction stored by the memory920, to control the transceiver940to receive a signal or send a signal. The processor910is configured to determine a first downlink subframe in which a cell-specific reference signal CRS is transmitted; the transceiver940is configured to send, to user equipment, indication information used to indicate the first downlink subframe; and the transceiver940is further configured to perform information transmission according to the first downlink subframe.

Therefore, in the base station of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with the base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the base station of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.

It should be understood that in the embodiment of the present invention, the processor910may be a central processing unit (CPU), or the processor910may be another general purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or another programmable logical device, discrete gate or transistor logical device, discrete hardware component, or the like. The general purpose processor may be a microprocessor or the processor may be any conventional processor and the like.

The memory920may include a read-only memory and a random access memory, and provides an instruction and data to the processor910. A part of the memory920may further include a non-volatile random access memory. For example, the memory920may further store device type information.

The bus system930may include a power bus, a control bus, a status signal bus, and the like in addition to a data bus. However, for clear description, various types of buses in the figure are marked as the bus system930.

In an implementation process, steps in the foregoing methods may be completed by using an integrated logic circuit in a form of hardware or an instruction in a form of software in the processor910. The steps of the methods disclosed in the embodiments of the present invention may be directly completed and performed by a hardware processor, or be completed and performed by combination of hardware and software modules in a processor. The software modules may be located in a mature storage medium in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electronically erasable programmable memory, or a register. The storage medium is located in the memory920. The processor910reads information in the memory920, and completes the steps of the foregoing methods by combining using of the hardware of the processor910. To avoid repetition, details are not described herein again.

Optionally, as an embodiment, the sending, by the transceiver940to user equipment, indication information used to indicate the first downlink subframe includes:

sending, to the user equipment, a downlink control channel that is carried in a downlink subframe0and/or a downlink subframe5, where the downlink control channel is used to indicate the first downlink subframe.

Optionally, as an embodiment, a cyclic redundancy check CRC code of the downlink control channel sent by the transceiver940is scrambled by using a first radio network temporary identifier RNTI, where the first RNTI includes at least one of a random access RNTI, a paging RNTI, and a system information RNTI, a first downlink control information DCI format used by the downlink control channel is a DCI format 1A, and a hybrid automatic repeat request HARQ process number field in the DCI format 1A is used to indicate the first downlink subframe.

Optionally, as an embodiment, a cyclic redundancy check CRC code of the downlink control channel sent by the transceiver940is scrambled by using a second radio network temporary identifier RNTI, where the second RNTI is used to indicate that the downlink control channel carries information that indicates the first downlink subframe, a second downlink control information DCI format used by the downlink control channel includes a CRS indicator field, the CRS indicator field is used to indicate the first downlink subframe, and a size of the second DCI format is the same as a size of a DCI format 1A or a DCI format 1C.

Optionally, as an embodiment, the sending, by the transceiver940to user equipment, indication information used to indicate the first downlink subframe includes:

sending higher layer signaling to the user equipment, where the higher layer signaling indicates a second downlink subframe used to transmit common search space of a physical downlink control channel PDCCH, and the second downlink subframe is used to indicate the first downlink subframe.

Optionally, as an embodiment, the first downlink subframe in which the CRS is transmitted is the same as the second downlink subframe.

Optionally, as an embodiment, the sending, by the transceiver940to user equipment, indication information used to indicate the first downlink subframe includes:

sending a master information block MIB to the user equipment, where the MIB is used to indicate the first downlink subframe.

Optionally, as an embodiment, the MIB includes a CRS indicator field of 10 bits, and the CRS indicator field is used to indicate the first downlink subframe.

The base station900according to this embodiment of the present invention may correspond to an execution body that executes the method of the embodiments of the present invention and the base station700, the foregoing and other operations and/or functions of the modules in the base station900are for implementing corresponding procedures in the methods inFIG. 1toFIG. 6, and for convenience, details are not described herein again.

Therefore, in the base station of this embodiment of the present invention, indication information is used to indicate a downlink subframe in which a cell-specific reference signal is transmitted, so that user equipment can know, according to the indication information, the downlink subframe in which the CRS is transmitted, and therefore the user equipment can correctly communicate with the base station according to the downlink subframe in which the CRS is transmitted. In this way, performance of a communications system can be improved.

In addition, in the base station of this embodiment of the present invention, an existing channel, existing signaling, an existing message, or the like is reused to indicate, to the user equipment, the first downlink subframe in which the CRS is transmitted, which can also simplify an operation procedure and save system resources.