WO2012055259A1

WO2012055259A1 - Method for transmission of uplink channel, base station and user equipment

Info

Publication number: WO2012055259A1
Application number: PCT/CN2011/076473
Authority: WO
Inventors: 戴博; 梁春丽; 任璐; 杨维维; 王瑜新
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-10-29
Filing date: 2011-06-28
Publication date: 2012-05-03
Also published as: CN101977099B; CN101977099A

Abstract

A method for transmission of uplink channel is provided in the present invention. The method includes: a base station transmits higher layer control information to a User Equipment (UE), and said higher layer control information indicates if the UE is permitted to transmit Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS) simultaneously. A base station is also provided in the present invention, which is configured so that higher layer control information is transmitted to a UE, and said higher layer control information indicates if the UE is permitted to transmit Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS) simultaneously. A UE is also provided in the present invention, which is configured to receive higher layer control information transmitted by a base station, and to determine transmission of uplink channel according to the higher layer control information.

Description

Method for transmitting uplink channel, base station and user equipment

Technical field

The present invention relates to the field of communications, and in particular, to a new method for transmitting a Sounding Reference Signal (SRS) and a PUCCH and PUSCH, a base station, and a user equipment in a system using a carrier aggregation technology.

Background technique

The uplink physical channel of the Long Term Evolution (LTE) system includes a Physical Random Access Channel (PARCH), a Physical Uplink Shared Channel (PUSCH), and a physical uplink control. Channel (Physical Uplink Control Channel, abbreviated as PUCCH). The uplink and downlink OFDM (Orthogonal Frequency Division Multiplexing) technology is used for multiplexing, and the reference signals and data are multiplexed by TDM (Time Division Multiplexing). The uplink reference signal is divided into a Demodulation Reference Signal (DMRS) and a Sounding Reference Signal (SRS), wherein the DMRS is divided into a PUCCH demodulation reference signal and a PUSCH demodulation reference signal. , used for different channel transmissions. The main role of the DMRS is for the estimation of the uplink channel and the coherent detection and demodulation of the base station (referred to as the eNB). The main function of the SRS is to measure the uplink channel, which is convenient for the eNB to perform frequency selective scheduling. In order to support such frequency selective scheduling, user equipment (UE, User Equipment) needs to measure a large bandwidth, which usually exceeds the bandwidth of data transmission, so SRS is a "wideband" reference signal. In LTE, the eNB may schedule each UE to transmit SRS periodically or periodically. When transmitting periodically, the transmission period may be 2/5/10/20/40/80/160/320 milliseconds. The period of SRS transmission and the offset of the subframe within the period are determined by the signaling SRSConfigurationInfo of the UE-specific lOBit. The bandwidth used by the UE to transmit the SRS depends on the transmission power of the UE, the number of UEs transmitting SRS in the cell, and the like. A more accurate uplink channel quality measurement can be obtained by using a larger transmission bandwidth. However, in the case where the uplink path loss is large, the UE needs a larger transmission power to maintain the transmission power density of the SRS. For each system bandwidth, eight different sets of SRS bandwidths are configured in LTE, within each set, Up to four different SRS bandwidths can be allocated to different UEs in LTE.

LTE specifies that the SRS is transmitted on the last symbol in the subframe, and in order to avoid mutual interference between the SRS and PUSCH data between different users, LTE specifies that the last symbol of the corresponding subframe cannot be used by any UE to transmit PUSCH data. In general, such a rule guarantees that PUCCH and SRS do not conflict with each other. If there is an SRS and a PUCCH transmitted simultaneously, the SRS is dropped to maintain the single carrier characteristic of the uplink. When the format of the PUCCH is PUCCH Formatl/la/lb (the time domain structure is as shown in FIG. 1), the truncated PUCCH format is specified, as shown in FIG. 2, at this time, the last symbol of the subframe is Used to send SRS. When the SRS collides with the PUCCH Format 2/2a/2b or the SR (Scheduling Request), the SRS is often lost. When the ACK/NACK is transmitted simultaneously, the truncated PUCCH and SRS can be selected for simultaneous transmission.

The LTE-A (LTE Advanced, LTE-A for short) system is a next-generation evolution system of the LTE system, which introduces the concept of Carrier Aggregation. The carrier aggregation LTE system bandwidth can be regarded as a component carrier, and each component carrier can also be referred to as a serving cell, that is, one spectrum can be aggregated by n component carrier frequencies (serving cells). Made. The resources of a RIO UE (User Equipment) are composed of n serving cells (component carriers) in the frequency domain, where one cell is called a primary cell and the other cells are called secondary cells. Uplink supports SU-MIMO, and up to 4 antennas can be used as the transmit antenna, that is, the UE can simultaneously transmit SRS on multiple antennas at the same time, and the eNB needs to estimate each strip according to the SRS received on each antenna. Status information on the channel. In the scenario of carrier aggregation, the PUCCH is fixed on a certain uplink component carrier, which will increase the probability that the uplink control channel and the SRS are simultaneously transmitted. If the SRS method is still used, the uplink channel will be affected. Measurement and estimation of downlink channel state, and LTE-A system supports simultaneous transmission of PUCCH and PUSCH, that is to say, in LTE-A, uplink single carrier is not the main consideration for uplink channel transmission design, therefore, LTE The transmission of various uplink channels in -A can be performed in a different manner than LTE. Therefore, it is necessary to rethink the transmission methods of various uplink channels in the carrier aggregation scenario. Summary of the invention

An object of the present invention is to provide an uplink channel transmission method, a base station, and a user equipment. In order to solve the above problem, the present invention provides an uplink channel sending method, including: the base station sends high layer control information to the user equipment, and indicates, by using the high layer control information, whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal. (SRS) Send at the same time.

The high-level control information is newly defined information; or, is, existing high-level control information.

The existing high-layer control information is the information of the PUCCH-PUSCH-Simultaneous Transmission (PUCCH-PUSCH-Simultaneous Transmission). When the value of the PUCCH-PUSCH-Simultaneous Transmission is true, the user equipment is allowed to simultaneously transmit the PUCCH and the SRS. When the value of the PUCCH-PUSCH-SimultaneousTransmission is false, it indicates that the user equipment is not allowed to simultaneously transmit the PUCCH and the SRS.

The high layer control information is proprietary to the user equipment.

The base station sends the high layer control information to the user equipment by using radio resource control signaling.

The step of indicating, by the high-layer control information, whether the user equipment allows the PUCCH and the SRS to be simultaneously transmitted, includes: the base station indicating, by using the same high-layer control information, whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted, and whether the PUCCH and the aperiodic SRS are allowed simultaneously. Transmit, or, the base station respectively indicates, by the independent high-layer control information, whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted, and whether the PUCCH and the aperiodic SRS are allowed to be simultaneously transmitted.

The method further includes: when the high-level control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, if the ACK/NACK and the SRS simultaneous transmission (AckNackSRS-SimultaneousTransmission) are true, the current subframe needs to simultaneously send the PUCCH format l/la/ In the case of lb/3 and SRS, the user equipment transmits PUCCH format l/la/lb/3 with a truncation structure while transmitting the SRS on the last symbol of the subframe.

The method further includes: when the high-layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, if the AckNackSRS-SimultaneousTransmission is H, the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS, the user The device transmits the PUCCH format l/la/lb/3 using a conventional structure while transmitting the SRS on the last symbol of the subframe. The method further includes: when the high-layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, if the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS, the user equipment sends the PUCCH format 2/2a/2b, while transmitting the SRS on the last symbol of the subframe.

The method further includes: when the high layer control information indicates that the user equipment does not allow PUCCH and

When the SRS is simultaneously transmitted, if the AckNackSRS-SimultaneousTransmission is true, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS, the user equipment sends the PUCCH format l/la/lb with a truncated structure. /3, while transmitting the SRS on the last symbol of the subframe.

When the SRS is simultaneously transmitted, if the AckNackSRS-SimultaneousTransmission is false, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS, the user equipment sends the PUCCH format l/la/lb/ using a conventional structure. 3, and the SRS is not sent on the subframe.

The method further includes: when the high-layer control information indicates that the user equipment does not allow the PUCCH to be sent simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS that carry the ACK/NACK, the user equipment The PUCCH format 2/2a/2b is transmitted in a conventional configuration, and the SRS is not transmitted on the subframe.

The method further includes: when the high-layer control information indicates that the user equipment allows the PUCCH to be transmitted simultaneously with the SRS, and when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS, the user equipment sends the PUCCH according to the scenario that only the PUCCH and the PUSCH are transmitted. PUSCH, and the PUSCH is not transmitted on the last symbol of the subframe, and the SRS is transmitted.

The SRS is a periodic SRS or an aperiodic SRS.

The method further includes: when the high-layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2 and the aperiodic SRS that only carry the channel state information, where the user equipment is in the The aperiodic SRS is sent on the subframe, and the PUCCH format 2 that only carries channel state information is not sent on the subframe.

The method further includes: when the high-level control information indicates that the user equipment does not allow the PUCCH to be sent simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format that carries the channel state information. In the case of the SRS and the periodic SRS, the user equipment sends the PUCCH format 2 carrying the channel state information on the subframe, and the periodic SRS is not sent on the subframe.

The method further includes: when the high-layer control information indicates that the user equipment does not allow the PUCCH to be sent simultaneously with the SRS, and the current subframe needs to simultaneously send a scheduling request (SR) and an aperiodic SRS, where the user equipment is on the subframe The SR is sent, and the aperiodic SRS is not sent on the subframe.

The method is applied to a scenario in which the SRS and the PUCCH are sent on the same component carrier, or the method is applied to a scenario in which the SRS is transmitted on the same component carrier as the PUCCH and the PUSCH.

The present invention further provides a base station, the base station is configured to: send high layer control information to the user equipment, and indicate, by using the high layer control information, whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal (SRS) to be simultaneously sent. .

The high layer control information is proprietary to the user equipment.

The base station is configured to indicate, by using the high layer control information, whether the user equipment allows PUCCH and SRS to be simultaneously transmitted according to the following manner: indicating, by using the same high layer control information, whether the user equipment allows PUCCH and periodic SRS to be simultaneously transmitted, and whether to allow PUCCH and aperiodic The SRSs are simultaneously transmitted; or the independent high-layer control information respectively indicates whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted, and whether the PUCCH and the aperiodic SRS are allowed to be simultaneously transmitted.

The user equipment is further configured to: receive the high layer control information sent by the base station, and determine the uplink channel transmission according to the high layer control information; wherein the high layer control information indicates whether the user equipment allows physical uplink Control channel (PUCCH) and measurement reference letter The number (SRS) is sent at the same time.

The user equipment is configured to determine transmission of an uplink channel by: when the high layer control information indicates that the user equipment allows PUCCH to be simultaneously transmitted with the SRS and the ACK/NACK and SRS simultaneous transmission (AckNackSRS-SimultaneousTransmission) is true, then the current When the subframe needs to transmit PUCCH format l/la/lb/3 and SRS simultaneously, the PUCCH format l/la/lb/3 is transmitted with the truncation structure, and the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to be sent simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, the PUCCH format is required to be simultaneously transmitted in the current subframe. At /la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted using a conventional structure while the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, when the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS Transmitting the PUCCH format 2/2a/2b with a conventional structure while transmitting the SRS on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is true, the PUCCH format needs to be simultaneously sent in the current subframe. When l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted with a truncation structure, and the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, the PUCCH format needs to be simultaneously sent in the current subframe. When l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted by a conventional structure, and the SRS is not transmitted on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, then the PUCCH format 2 carrying the ACK/NACK needs to be simultaneously transmitted in the current subframe. In the case of /2a/2b and SRS, the PUCCH format 2/2a/2b is transmitted using a conventional structure, and the SRS is not transmitted on the subframe. The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS, according to only The PUCCH and PUSCH transmitted scenarios transmit PUCCH and PUSCH, and do not transmit PUSCH on the last symbol of the subframe, and transmit the SRS.

The SRS is a periodic SRS or an aperiodic SRS.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, the PUCCH format that only carries the channel state information needs to be simultaneously transmitted in the current subframe. 2 and aperiodic SRS, the aperiodic SRS is sent on the subframe, and the PUCCH format 2 that only carries channel state information is not sent on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, then the PUCCH format 2 that needs to simultaneously transmit the channel state information in the current subframe is required. And the periodic SRS, the PUCCH format 2 carrying the channel state information is sent on the subframe, and the periodic SRS is not sent on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, then the scheduling request (SR) and the aperiod need to be simultaneously sent in the current subframe. In the SRS, the SR is sent on the subframe, and the aperiodic SRS is not sent on the subframe.

The present invention provides a method for transmitting various uplink channels in a carrier aggregation scenario. The present invention solves the problem of simultaneous transmission of SRS, PUCCH, PUCCH, SRS, and PUSCH by setting high-level signaling enablement, and improves SRS transmission efficiency, so that the base station can obtain uplink and downlink channel information state information more accurately and timely, thereby performing more Good scheduling to improve overall system performance. BRIEF abstract

1 is a schematic diagram of a time-frequency position of a PUCCH format 1/la/lb in the prior art;

2 is a diagram showing a truncated structure of PUCCH format 1/la/lb when SRS is transmitted in the prior art. Frequency position diagram;

3 is a schematic diagram of a time-frequency position of simultaneous transmission of PUCCH format 1/la/lb and SRS in the present invention;

4 is a schematic diagram showing the time-frequency positions of PUCCH format 1/la/lb and SRS and PUSCH simultaneously transmitted in the present invention;

5 is a schematic diagram of a time-frequency position of a PUCCH format 2/2a/2b/3 in the prior art;

6 is a schematic diagram showing a time-frequency position of a truncated structure of PUCCH format 3 when SRS is transmitted in the prior art;

7 is a schematic diagram showing the time-frequency position of simultaneous transmission of PUCCH format 2/2a/2b/3 and SRS in the present invention;

Figure 8 is a diagram showing the time-frequency positions of PUCCH format 2/2a/2b/3 and SRS and PUSCH simultaneously transmitted in the present invention.

Preferred embodiment of the invention

The core idea of the present invention is: The base station configures the user equipment whether to allow the PUCCH to transmit the high layer control information simultaneously with the SRS, and the user equipment determines the uplink channel transmission according to the high layer control information.

The present invention provides an uplink channel sending method, including: the base station sends high layer control information to the user equipment, and the high layer control information indicates whether the user equipment allows the PUCCH to be simultaneously transmitted with the SRS.

The high layer control information is UE specific (user equipment specific), and the user equipment is notified by RRC (Radio Resource Control) signaling.

The high-level control information may be configured independently or in the same configuration for the periodic and aperiodic SRS. That is, the base station indicates, by using the same high-layer control information, whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted and whether the PUCCH and the PUCCH are allowed. The aperiodic SRS is simultaneously transmitted; or the base station separately indicates whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted through independent high-layer control information, and whether the PUCCH and the aperiodic SRS are allowed to be simultaneously transmitted.

When the high layer control information indicates that the user equipment allows the PUCCH to transmit simultaneously with the SRS, if the high layer information ACK/NACK and SRS simultaneous transmission (AckNackSRS-SimultaneousTransmission) is TRUE (true), the current subframe needs to be the same When transmitting PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS), the UE will use the truncation structure to transmit PUCCH format l/la/lb/3, while the last symbol in the subframe Sending SRS on top; If the high-level information AckNackSRS-SimultaneousTransmission is FALSE, the current subframe needs to transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS) simultaneously, the UE will use the conventional structure. Send PUCCH format l/la/lb/3, and send SRS on the last symbol of the subframe;

When the high-layer control information indicates that the user equipment allows the PUCCH to transmit simultaneously with the SRS, when the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS (including the periodic SRS and the aperiodic SRS), the UE adopts the conventional structure. Transmitting PUCCH format 2/2a/2b while transmitting SRS on the last symbol of the subframe;

When the high-level control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, if the high-level information AckNackSRS-SimultaneousTransmission is TRUE, the current subframe needs to simultaneously transmit the PUCCH format l/la/lb/3 and the SRS (including the period and In the case of aperiodic SRS, the UE will transmit the PUCCH format l/la/lb/3 with the truncation structure, and send the SRS on the last symbol of the subframe;

When the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, if the high-level information AckNackSRS-SimultaneousTransmission is FALSE, the current subframe needs to simultaneously transmit the PUCCH format l/la/lb/3 and the SRS (including the period and the non- In the case of the periodic SRS), the UE will transmit the PUCCH format l/la/lb/3 using the conventional structure, and the UE will not transmit the SRS; when the high-layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, the current sub- When a frame needs to simultaneously transmit PUCCH format 2/2a/2b and SRS (including periodic and aperiodic SRS) carrying ACK/NACK, the UE will transmit PUCCH format 2/2a/2b using the conventional structure, and the UE will not transmit SRS. ;

When the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2 and the aperiodic SRS carrying the CSI (Channel state information), the UE will send the aperiodic The SRS, at the same time, the UE will not transmit the PUCCH format 2 carrying the CSI; when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2 and the periodic SRS carrying the channel state information, Transmitting, by the user equipment, the bearer letter on the subframe The PUCCH format 2 of the channel status information, and the period SRS is not transmitted on the subframe.

When the high-layer control information indicates that the user equipment does not allow the PUCCH to be transmitted simultaneously with the SRS, when the current subframe needs to simultaneously send the SR and the aperiodic SRS, the user equipment sends the SR on the subframe, and the child The aperiodic SRS is not transmitted on the frame.

The high-level control information is newly defined information; or, is, existing high-level control information. The high-level control information may be that the base station implicitly indicates whether the user equipment allows the PUCCH and the SRS to be simultaneously transmitted according to the existing high-level configuration information.

The existing high-level configuration information may be PUCCH-PUSCH-Simultaneous Transmission (PUCCH-PUSCH-Simultaneous Transmission) information; when PUCCH-PUSCH-SimultaneousTransmission is TRUE, the user equipment allows PUCCH and SRS to be simultaneously transmitted, when PUCCH-PUSCH-SimultaneousTransmission When FALSE, the user equipment does not allow PUCCH and SRS to be sent simultaneously.

When the high-layer control information indicates that the user equipment allows the PUCCH to transmit simultaneously with the SRS, when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS (including the periodic SRS and the aperiodic SRS), the PUCCH and the PUSCH are transmitted according to only the PUCCH and the PUSCH. The scenario is sent, where the PUSCH is not sent on the last symbol of the uplink component carrier where the SRS is located, and the SRS is sent.

In order to facilitate the understanding of the present invention, the present invention will be further described below in conjunction with the specific embodiments. method one:

Defining a new high-level information PUCCH-SRS-SimultaneousTransmission, when the PUCCH-SRS-SimultaneousTransmission is TRUE, the user equipment is allowed to simultaneously transmit the PUCCH and the SRS, and when the PUCCH-SRS-SimultaneousTransmission is the FLASE, the user equipment is not allowed to simultaneously transmit the PUCCH and the SRS;

Method 2:

The base station implicitly indicates whether the user equipment allows the PUCCH and the SRS to be simultaneously transmitted according to the existing high-level configuration information. The existing high-level configuration information may be

PUCCH-PUSCH-SimultaneousTransmission ;

When PUCCH-PUSCH-SimultaneousTransmission is TRUE, the user equipment is allowed to simultaneously transmit PUCCH and SRS. When PUCCH-PUSCH-SimultaneousTransmission is FALSE, the user equipment is not allowed to send PUCCH and SRS at the same time.

Example 1:

Only scenes where PUCCH and SRS are transmitted simultaneously:

When the PUCCH-SRS-SimultaneousTransmission is TRUE, if the high-level information AckNackSRS-SimultaneousTransmission is TRUE, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS), the UE will use Truncating the structure to send PUCCH format l/la/lb/3, and sending SRS on the last symbol of the subframe, as shown in Figure 2 and Figure 6; if the high-level information AckNackSRS-SimultaneousTransmission is FALSE, the current subframe needs to be simultaneously When PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS) are transmitted, the UE will transmit PUCCH format l/la/lb/3 using the conventional structure and send on the last symbol of the subframe. SRS, as shown in Figures 3 and 7;

When PUCCH-SRS-SimultaneousTransmission is TRUE, when the current subframe needs to simultaneously transmit PUCCH format 2/2a/2b and SRS (including periodic SRS and aperiodic SRS), the UE will transmit PUCCH format 2/2a/2b using the conventional structure. And send the SRS on the last symbol of the subframe, as shown in Figure 7;

When the PUCCH-SRS-SimultaneousTransmission is FLASE, if the high-level information AckNackSRS-SimultaneousTransmission is TRUE, then the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS), the UE will 釆Transmitting PUCCH format l/la/lb/3 with a truncated structure, and transmitting SRS on the last symbol of the subframe, as shown in FIG. 2 and FIG. 6;

When PUCCH-SRS-SimultaneousTransmission is FLASE, if the high-level information AckNackSRS-SimultaneousTransmission is FALSE, the current subframe needs to transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS) simultaneously, the UE will use Often The structure is configured to send PUCCH format l/la/lb/3, and the UE will not send SRS, as shown in Figure 1 and Figure 5;

When PUCCH-SRS-SimultaneousTransmission is FLASE, when the current subframe needs to simultaneously transmit PUCCH format 2/2a/2b and SRS (including periodic and aperiodic SRS) carrying ACK/NACK, the UE will use the conventional structure to transmit PUCCH format. 2/2a/2b, while the UE will not send SRS, as shown in Figure 1;

When PUCCH-SRS-SimultaneousTransmission is FLASE, when the current subframe needs to transmit the PUCCH format 2 and the aperiodic SRS carrying the CSI, the UE will send the aperiodic SRS, and the UE will not send the PUCCH format 2 carrying the CSI.

Example 2:

Only scenes where PUCCH and SRS are simultaneously transmitted;

When the PUCCH-PUSCH-SimultaneousTransmission is TRUE, if the high-level information AckNackSRS-SimultaneousTransmission is TRUE, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS), the UE will use the UE. Truncated structure to send PUCCH format l/la/lb/3, and send SRS on the last symbol of the subframe; if the high-level information AckNackSRS-SimultaneousTransmission is FALSE, the current subframe needs to send PUCCH format l/la/lb/ at the same time 3 and SRS (including periodic and aperiodic SRS), the UE will use the normal structure to send PUCCH format l/la/lb/3, and send SRS on the last symbol of the subframe, as shown in Figure 4 and Figure 8. The frequency domain locations of the PUSCH and the SRS may be the same or different.

When PUCCH-PUSCH-SimultaneousTransmission is TRUE, when the current subframe needs to simultaneously transmit PUCCH format 2/2a/2b and SRS (including periodic SRS and aperiodic SRS), the UE will transmit PUCCH format 2/2a/2b using the conventional structure. And transmitting the SRS on the last symbol of the subframe, as shown in FIG. 8, where the frequency domain positions of the PUSCH and the SRS may be the same or different;

When the PUCCH-PUSCH-SimultaneousTransmission is FLASE, if the high-level information AckNackSRS-SimultaneousTransmission is TRUE, the current subframe needs to be sent simultaneously. When PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS) are sent, the UE will transmit PUCCH format l/la/lb/3 with truncation structure and send on the last symbol of the subframe. SRS, as shown in Figure 2 and Figure 6;

When the PUCCH-PUSCH-SimultaneousTransmission is FLASE, if the high-level information AckNackSRS-SimultaneousTransmission is FALSE, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS (including periodic and aperiodic SRS), the UE will use the UE. The conventional structure sends PUCCH format l/la/lb/3, and the UE will not send SRS, as shown in FIG. 1 and FIG. 5;

When PUCCH-PUSCH-SimultaneousTransmission is FLASE, when the current subframe needs to simultaneously transmit PUCCH format 2/2a/2b and SRS (including periodic and aperiodic SRS) carrying ACK/NACK, the UE will use the conventional structure to transmit PUCCH format. 2/2a/2b, while the UE will not send SRS, as shown in Figure 5;

When PUCCH-PUSCH-SimultaneousTransmission is FLASE, when the current subframe needs to transmit both PUCCH format 2 and aperiodic SRS carrying CSI, the UE will send a non-periodic SRS, and the UE will not transmit PUCCH format 2 carrying only CSI.

Example 3

a scenario in which PUSCH, PUCCH, and SRS are simultaneously transmitted;

When the high-layer control information indicates that the PUCCH-PUSCH-SimultaneousTransmission is TRUE, when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS (including the periodic SRS and the aperiodic SRS), the PUCCH and the PUSCH are transmitted according to the scenario in which only the PUCCH and the PUSCH are transmitted, where The PUSCH is not sent on the last symbol of the uplink component carrier where the SRS is located, and the SRS is sent;

When the PUCCH-PUSCH-SimultaneousTransmission is the FLASE, the UCI (Uplink Control Information) is carried on the PUSCH, where the PUSCH is not sent on the last symbol of the uplink component carrier where the SRS is located, and the SRS is sent; where the UCI includes the ACK/ One or more of NACK, CSI, SR (Scheduling Request). Example 4

When the high-level control information indicates that the user equipment does not allow the PUCCH and the SRS to transmit simultaneously: the scenario that only PUCCH and SRS are simultaneously transmitted;

When the current subframe needs to transmit ACK/NACK and SRS (periodic and aperiodic) simultaneously, the UE will transmit ACK/NACK on the subframe and not transmit the SRS;

When the current subframe needs to transmit both the SR (Scheduling Request) and the SRS (periodic and aperiodic), the UE will transmit the SR on the subframe and not transmit the aperiodic SRS; the current subframe needs to transmit the CSI at the same time. And the periodic SRS, the UE will transmit CSI on the subframe, and does not transmit the periodic SRS;

When the current subframe needs to transmit CSI and aperiodic SRS simultaneously, the UE will transmit the non-periodic SRS on the subframe and not transmit the CSI;

Currently, the scenario where the PUSCH, the PUCCH, and the SRS are simultaneously transmitted, the UCI is carried on the PUSCH, where the PUSCH is not transmitted on the last symbol, and the SRS is transmitted; the UCI includes one or more of ACK/NACK, CSI, and SR.

The present invention further provides a base station, where the base station is configured to: send high layer control information to the user equipment, and the high layer control information indicates whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal (SRS) to be simultaneously transmitted. The high-level control information is newly defined information; or, is, existing high-level control information. The high-level control information is that the existing PUCCH and PUSCH are simultaneously transmitted.

(PUCCH-PUSCH-SimultaneousTransmission) information, when the value of the PUCCH-PUSCH-SimultaneousTransmission is true, the user equipment is allowed to simultaneously send the PUCCH and the SRS, and when the value of the PUCCH-PUSCH-SimultaneousTransmission is false, the user equipment is not allowed to send at the same time. PUCCH and SRS.

The high layer control information is specific to the user equipment. The base station is configured to send the high layer control information to the user equipment by using radio resource control signaling. The base station indicates, by using the same high layer control information, whether the user equipment allows PUCCH. Simultaneously transmitting with the periodic SRS and allowing the PUCCH and the aperiodic SRS to be simultaneously transmitted; or the base station respectively indicates whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted through independent high-layer control information, whether the PUCCH and the aperiodic are allowed. SRS is sent simultaneously.

The user equipment is further configured to: receive the high layer control information sent by the base station, and determine the uplink channel transmission according to the high layer control information; wherein the high layer control information indicates whether the user equipment allows physical uplink The Control Channel (PUCCH) and the Measurement Reference Signal (SRS) are transmitted simultaneously.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to transmit simultaneously with the SRS and the AckNackSRS-Simultaneous Transmission information is true, in the current subframe. When PUCCH format l/la/lb/3 and SRS need to be transmitted simultaneously, PUCCH format l/la/lb/3 is transmitted with a truncation structure, and SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the uplink channel transmission by: when the high layer control information indicates that the user equipment allows the PUCCH to be sent simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, and the PUCCH format needs to be simultaneously sent in the current subframe. For l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted using a conventional structure while the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, and the PUCCH format 2/2a/2b and the SRS need to be simultaneously transmitted in the current subframe. The PUCCH format 2/2a/2b is transmitted with a conventional structure while the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is true, and the PUCCH needs to be simultaneously sent in the current subframe. When format l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted with a truncation structure, and the SRS is transmitted on the last symbol of the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-level control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, and the current subframe needs to be simultaneously sent. In PUCCH format l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted by a conventional structure, and the SRS is not transmitted on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, the PUCCH format that carries the ACK/NACK is required to be simultaneously transmitted in the current subframe. In the case of 2/2a/2b and SRS, the PUCCH format 2/2a/2b is transmitted using a conventional structure, and the SRS is not transmitted on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS, according to Only the PUCCH and PUSCH transmission scenarios transmit PUCCH and PUSCH, and the PUSCH is not transmitted on the last symbol, and the SRS is transmitted.

The SRS is a periodic SRS or an aperiodic SRS.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, the PUCCH that only carries the channel state information needs to be simultaneously transmitted in the current subframe. In the format 2 and the aperiodic SRS, the aperiodic SRS is sent on the subframe, and the PUCCH format 2 that only carries channel state information is not sent on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high-layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, the PUCCH format that needs to simultaneously transmit the bearer channel state information in the current subframe In the case of the SRS and the periodic SRS, the PUCCH format 2 carrying the channel state information is transmitted on the subframe, and the periodic SRS is not transmitted on the subframe.

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, the scheduling request (SR) and the non-send need to be simultaneously sent in the current subframe. During periodic SRS, the SR is sent on the subframe, and the aperiodic SRS is not sent on the subframe.

It can be seen from the above embodiments that the method provided by the present invention solves the problem of simultaneous transmission of SRS, PUCCH, PUCCH, SRS, and PUSCH by setting corresponding signaling enablement, and improves SRS. The transmission efficiency enables the base station to obtain uplink and downlink channel state information more accurately and timely, thereby performing better scheduling and improving overall system performance.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Industrial applicability

Compared with the prior art, the present invention solves the problem of simultaneous transmission of SRS, PUCCH, PUCCH, SRS, and PUSCH by setting high-layer signaling enablement, improves SRS transmission efficiency, and enables the base station to acquire uplink and downlink channels more accurately and timely. Signal status information for better scheduling and overall system performance.

Claims

Claim

1. An uplink channel sending method, comprising:

The base station sends the high layer control information to the user equipment, and indicates, by the high layer control information, whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal (SRS) to be simultaneously transmitted.

2. The method of claim 1 wherein

3. The method of claim 2, wherein

The existing high-layer control information is information that is transmitted by the existing PUCCH and the physical uplink shared channel (PUSCH) (PUCCH-PUSCH-Simultaneous Transmission), and when the PUCCH-PUSCH-SimultaneousTransmission is true, the user equipment is allowed to be indicated. The PUCCH and the SRS are simultaneously sent. When the value of the PUCCH-PUSCH-SimultaneousTransmission is false, the user equipment is not allowed to simultaneously transmit the PUCCH and the SRS.

4. The method of claim 1, wherein the high layer control information is user device specific.

5. The method according to claim 1, wherein the base station sends the high layer control information to the user equipment by using radio resource control signaling.

The method of claim 1, wherein the step of indicating, by the higher layer control information, whether the user equipment allows PUCCH and SRS to be simultaneously transmitted comprises:

The base station indicates, by using the same high-layer control information, whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted, and whether the PUCCH and the aperiodic SRS are simultaneously transmitted; or the base station separately indicates whether the user equipment allows the PUCCH through the independent high-layer control information. Simultaneously transmitted with the periodic SRS, whether the PUCCH and the aperiodic SRS are allowed to be simultaneously transmitted.

7. The method of claim 1 further comprising:

When the high layer control information indicates that the user equipment allows the PUCCH to be transmitted simultaneously with the SRS, if the ACK/NACK and SRS simultaneous transmission (AckNackSRS-SimultaneousTransmission) are true, the current subframe needs to be simultaneously transmitted. 11〇01 &111^ 1/1 /11)/3 and 81 8, the user setting The PUCCH format l/la/lb/3 is transmitted with a truncated structure, and the SRS is transmitted on the last symbol of the subframe.

8. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment allows the PUCCH to be transmitted simultaneously with the SRS, if the AckNackSRS-SimultaneousTransmission is false, and the current subframe needs to simultaneously transmit the PUCCH format l/la/lb/3 and the SRS, the user equipment uses the conventional The structure transmits the PUCCH format l/la/lb/3 while transmitting the SRS on the last symbol of the subframe.

9. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment allows the PUCCH to be transmitted simultaneously with the SRS, if the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS, the user equipment sends the PUCCH format 2/2a by using a conventional structure. /2b while transmitting the SRS on the last symbol of the subframe.

10. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to be transmitted simultaneously with the SRS, if the AckNackSRS-SimultaneousTransmission is true, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS, the user equipment uses The truncated structure transmits the PUCCH format l/la/lb/3 while transmitting the SRS on the last symbol of the subframe.

11. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to be transmitted simultaneously with the SRS, if the AckNackSRS-SimultaneousTransmission is false, and the current subframe needs to simultaneously transmit PUCCH format l/la/lb/3 and SRS, the user equipment uses The conventional structure transmits the PUCCH format l/la/lb/3, and the SRS is not transmitted on the subframe.

12. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to be transmitted simultaneously with the SRS, when the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS carrying the ACK/NACK, the user equipment uses the conventional structure to send the The PUCCH format 2/2a/2b is described, and the SRS is not transmitted on the subframe.

13. The method of claim 1 further comprising: When the high-layer control information indicates that the user equipment allows the PUCCH to be transmitted simultaneously with the SRS, when the current subframe needs to transmit the PUCCH, the PUSCH, and the SRS simultaneously, the user equipment sends the PUCCH and the PUSCH according to the scenario in which only the PUCCH and the PUSCH are transmitted, and The PUSCH is not transmitted on the last symbol of the sub-frame, and the SRS is transmitted.

14. The method according to any one of claims 7 to 13, wherein

The SRS is a periodic SRS or an aperiodic SRS.

15. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2 and the aperiodic SRS that only carry the channel state information, the user equipment sends the subframe. The aperiodic SRS, and the PUCCH format 2 that only carries channel state information is not sent on the subframe.

16. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to be transmitted simultaneously with the SRS, and the current subframe needs to simultaneously transmit the PUCCH format 2 and the periodic SRS that carry the channel state information, the user equipment sends the The PUCCH format 2 carrying the channel state information, and the periodic SRS is not transmitted on the subframe.

17. The method of claim 1 further comprising:

When the high-level control information indicates that the user equipment does not allow the PUCCH to be sent simultaneously with the SRS, and the current subframe needs to simultaneously send the scheduling request (SR) and the aperiodic SRS, the user equipment sends the SR in the subframe. And the aperiodic SRS is not sent on the subframe.

18. The method according to any one of claims 1 to 13, 15 to 17, wherein

A base station, the base station is configured to: send high-level control information to the user equipment, and indicate, by the high-layer control information, whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal (SRS) to be simultaneously transmitted.

20. The base station according to claim 19, wherein The high-level control information is newly defined information; or, is, existing high-level control information.

21. The base station according to claim 20, wherein

The base station according to claim 19, wherein the high layer control information is specific to the user equipment.

The base station according to claim 19, wherein the base station is configured to send the high layer control information to the user equipment by using radio resource control signaling.

The base station according to claim 19, wherein the base station is configured to indicate, by using the high layer control information, whether the user equipment allows PUCCH and SRS to be simultaneously transmitted according to the following manner: indicating, by using the same high layer control information, whether the user equipment allows PUCCH Simultaneously transmitting with the periodic SRS and allowing the PUCCH and the aperiodic SRS to be simultaneously transmitted; or respectively, indicating whether the user equipment allows the PUCCH and the periodic SRS to be simultaneously transmitted through independent high-layer control information, whether to allow the PUCCH and the aperiodic SRS to be simultaneously transmitted. .

25, a user equipment,

The user equipment is configured to: receive high-layer control information sent by the base station, and determine, according to the high-layer control information, the uplink channel, where the high-layer control information indicates whether the user equipment allows the physical uplink control channel (PUCCH) and the measurement reference signal. (SRS) Send at the same time.

The user equipment according to claim 25, wherein

The user equipment is configured to determine transmission of an uplink channel by: when the high layer control information indicates that the user equipment allows PUCCH to be simultaneously transmitted with the SRS and the ACK/NACK and SRS simultaneous transmission (AckNackSRS-SimultaneousTransmission) is true, if If the current subframe needs to transmit PUCCH format l/la/lb/3 and SRS simultaneously, then the PUCCH format l/la/lb/3 is transmitted with the truncation structure, and the SRS is transmitted on the last symbol of the subframe.

27. The user equipment according to claim 25, wherein The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, if the current subframe needs to simultaneously send the PUCCH format l/la/lb/3 and SRS, then the PUCCH format l/la/lb/3 is transmitted using a conventional structure while the SRS is transmitted on the last symbol of the subframe.

28. The user equipment of claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, and when the current subframe needs to simultaneously transmit the PUCCH format 2/2a/2b and the SRS Then, the PUCCH format 2/2a/2b is transmitted by a conventional structure while the SRS is transmitted on the last symbol of the subframe.

29. The user equipment of claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is true, if the current subframe needs to simultaneously send the PUCCH format For l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted with a truncation structure, and the SRS is transmitted on the last symbol of the subframe.

30. The user equipment according to claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to transmit simultaneously with the SRS, and the AckNackSRS-SimultaneousTransmission is false, if the PUCCH needs to be simultaneously sent in the current subframe Format l/la/lb/3 and SRS, the PUCCH format l/la/lb/3 is transmitted in a conventional structure, and the SRS is not transmitted on the subframe.

The user equipment according to claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, and the PUCCH format 2/ carrying the ACK/NACK is required to be simultaneously transmitted in the current subframe. In the case of 2a/2b and SRS, the PUCCH format 2/2a/2b is transmitted using a conventional structure, and the SRS is not transmitted on the subframe.

32. The user equipment according to claim 25, wherein The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment allows the PUCCH to be simultaneously transmitted with the SRS, and when the current subframe needs to simultaneously transmit the PUCCH, the PUSCH, and the SRS, according to only the PUCCH The PUCCH and the PUSCH are transmitted in the scenario of the PUSCH transmission, and the PUSCH is not transmitted on the last symbol of the subframe, and the SRS is transmitted.

33. The user equipment according to any one of claims 25 to 32, wherein

The SRS is a periodic SRS or an aperiodic SRS.

34. The user equipment of claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, and the PUCCH format 2 that only carries the channel state information needs to be simultaneously transmitted in the current subframe. And the aperiodic SRS, the aperiodic SRS is sent on the subframe, and the PUCCH format that only carries the channel state information is not sent on the subframe.

35. The user equipment of claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, and the PUCCH format 2 that carries the channel state information needs to be simultaneously transmitted in the current subframe. During periodic SRS, the PUCCH format 2 carrying the channel state information is transmitted on the subframe, and the periodic SRS is not transmitted on the subframe.

36. The user equipment of claim 25, wherein

The user equipment is configured to determine the transmission of the uplink channel by: when the high layer control information indicates that the user equipment does not allow the PUCCH to be simultaneously transmitted with the SRS, and the scheduling request (SR) and the aperiodic SRS are simultaneously sent in the current subframe. The SR is sent on the subframe, and the aperiodic SRS is not sent on the subframe.