Patent Publication Number: US-2019174523-A1

Title: Timing adjustment method, base station, terminal and communication system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of Chinese Patent Application No. 201610659286.3, filed on Aug. 11, 2016, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to the field of communication technologies, and in particular, to a timing adjustment method, base station, terminal and communication system. 
     BACKGROUND 
     Long Term Evolution (LTE) technology supports two duplex modes: Frequency Division Duplex (FDD) and Time Division Duplex (TDD). The TDD mode means that the uplink and downlink use the same working frequency band, and uplink and downlink signals are transmitted at different moments. The FDD mode means that the uplink and downlink use different working frequency bands, and the uplink and downlink signals are transmitted on different frequency carriers at the same moment. 
     In the LTE system, the length of one radio frame of the FDD mode and the TDD mode is 10 ms. One radio frame includes 10 subframes. The length of each subframe is 1 ms. 
     Seven TDD uplink and downlink subframe configurations are defined for a radio frame of the TDD mode, as shown in Table 1, where D represents a downlink subframe, U represents an uplink subframe, and S represents a special subframe. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Con- 
                 Conversion  
                   
               
               
                 figuration 
                 point 
                 subframe No. 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 No. 
                 period 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 0 
                  5 ms 
                 D 
                 S 
                 U 
                 U 
                 U 
                 D 
                 S 
                 U 
                 U 
                 U 
               
               
                 1 
                  5 ms 
                 D 
                 S 
                 U 
                 U 
                 D 
                 D 
                 S 
                 U 
                 U 
                 D 
               
               
                 2 
                  5 ms 
                 D 
                 S 
                 U 
                 D 
                 D 
                 D 
                 S 
                 U 
                 D 
                 D 
               
               
                 3 
                 10 ms 
                 D 
                 S 
                 U 
                 U 
                 U 
                 D 
                 D 
                 D 
                 D 
                 D 
               
               
                 4 
                 10 ms 
                 D 
                 S 
                 U 
                 U 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
               
               
                 5 
                 10 ms 
                 D 
                 S 
                 U 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
               
               
                 6 
                 10 ms 
                 D 
                 S 
                 U 
                 U 
                 U 
                 D 
                 S 
                 U 
                 U 
                 D 
               
               
                   
               
            
           
         
       
     
     In order to improve a transmission rate of a user, an LTE-Advanced (LTE-A) technology is proposed. An LTE-A TDD system and the LTE have the same Hybrid Automatic Repeat Request (HARQ) transmission timing, which includes an HARQ process of downlink data and an HARQ process of uplink data. During the HARQ process of the uplink data, a base station schedules Physical Uplink Shared Channel (PUSCH) resources by transmitting a Physical Downlink Control Channel (PDCCH) to a UE. After receiving the PDCCH, the UE transmits uplink data on a PUSCH channel specified by the PDCCH according to a timing relationship from the PDCCH to the PUSCH. 
     For the timing relationship from the PDCCH to the PUSCH, i.e., the timing relationship of the PUSCH scheduling, assuming the UE receives the PDCCH in a downlink subframe n, the PDCCH controls the PUSCH in an uplink subframe n+k. In this case, a value of k is defined in Table 2. Specifically, for the uplink and downlink configurations 1 to 6, the number of uplink subframes is less than that of downlink subframes, and a unique HARQ transmission timing may be configured. As shown in Table 2, the PUSCH may not be scheduled in one downlink subframe, or the PUSCH in one uplink subframe may only be scheduled. For the uplink and downlink configuration 0, the number of the uplink subframes is greater than that of the downlink subframes, and the PDCCH of each downlink subframe may schedule the PUSCH in two uplink subframes. As such, a UL index (used to indicate the uplink no.) is used in the PDCCH to support scheduling of the PUSCH in the two uplink subframes. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Configuration 
                 Downlink subframe No. n 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 No. 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 0 
                 4, 7 
                 6, 7 
                   
                   
                   
                 4, 7 
                 6, 7 
                   
                   
                   
               
               
                 1 
                   
                 6 
                   
                   
                 4 
                   
                 6 
                   
                   
                 4 
               
               
                 2 
                   
                   
                   
                 4 
                   
                   
                   
                   
                 4 
                   
               
               
                 3 
                 4 
                   
                   
                   
                   
                   
                   
                   
                 4 
                 4 
               
               
                 4 
                   
                   
                   
                   
                   
                   
                   
                   
                 4 
                 4 
               
               
                 5 
                   
                   
                   
                   
                   
                   
                   
                   
                 4 
                   
               
               
                 6 
                 7 
                 7 
                   
                   
                   
                 7 
                 7 
                   
                   
                 5 
               
               
                   
               
            
           
         
       
     
     In the uplink and downlink configuration 0, there are three types of UL Index indications in the PDCCH which schedules the PUSCH, two of which schedule the PUSCH in a single subframe. The scheduling of the PUSCH in the single subframe is indicated by only one bit of two bits of the UL Index being 1. The other is to schedule the PUSCH in two subframes at a time, indicated by both two bits of the UL Index being 1. As shown in  FIG. 1 , when the UE receives the PDCCH in the downlink subframe 0 and the MSB of the UL Index is “1”, the PUSCH in the uplink subframe 4 is scheduled. When the LSB of the UL Index is “1”, the PUSCH in the uplink subframe 7 is scheduled. When the MSB and the LSB of the UL index are both “1”, the PUSCHs in the uplink subframe 4 and the uplink subframe 7 are scheduled. When the UE receives the PDCCH in the downlink subframe 1 and the MSB of the UL Index is “1”, the PUSCH in the uplink subframe 7 is scheduled. When the LSB of the UL Index is “1”, the PUSCH in the uplink subframe 8 is scheduled. When the MSB and the LSB of the UL Index are both “1”, the PUSCHs in the uplink subframe 7 and the uplink subframe 8 are scheduled. 
     During the HARQ process of downlink data, the base station sends a Physical Downlink Shared Channel (PDSCH) to the UE. After receiving the PDSCH, the UE returns acknowledgement of the hybrid automatic repeat request (HARQ-ACK) of the PDSCH in the PUSCH or a Physical Uplink Control Channel (PUCCH) according to a timing relationship from the PDSCH to the PUSCH/PUCCH. 
     For the timing relationship from the PDSCH to the PUSCH/PUCCH, i.e., the PDSCH feedback HARQ-ACK timing relationship, assuming the UE returns the HARQ-ACK in the PUCCH/PUSCH of the uplink subframe n, the PUCCH/PUSCFH indicates HARQ-ACK information of a PDSCH in a downlink subframe n−k, or HARQ-ACK information released by SPS. In this case, a value of k∈K is defined in Table 3. K is a set of M elements (k0, k1, . . . , kM−1), which is associated to the subframe number and the uplink and downlink configurations, and is called a downlink association set. Element k is called a downlink association number. In the present disclosure, a downlink subframe set corresponding to the downlink association set is simply referred to as a bundling window. That is, for all elements k in K, a set formed by n−k is called the bundling window, (n−k, k∈K). The number of the elements in the bundling window is the size of the bundling window. 
     
       
         
           
               
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Configuration  
                 Subframe n 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 No. 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
               
               
                   
               
               
                 0 
                 — 
                 — 
                 6 
                 — 
                 4 
                 — 
                 — 
                 6 
                 — 
                 4 
               
               
                 1 
                 — 
                 — 
                 7, 6 
                 4 
                 — 
                 — 
                 — 
                 7, 6 
                 4 
                 — 
               
               
                 2 
                 — 
                 — 
                 8, 7, 4, 6 
                 — 
                 — 
                 — 
                 — 
                 8, 7,  
                 — 
                 — 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                 4, 6 
                   
                   
               
               
                 3 
                 — 
                 — 
                 7, 6, 11 
                 6, 5 
                 5, 4 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 4 
                 — 
                 — 
                 12, 8,  
                 6, 5, 4, 7 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                   
                   
                 7, 11 
                   
                   
                   
                   
                   
                   
                   
               
               
                 5 
                 — 
                 — 
                 13, 12,  
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                   
                   
                   
                 9, 8, 7, 5,  
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                   
                 4, 11, 6 
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
                 — 
                 — 
                 7 
                 7 
                 5 
                 — 
                 — 
                 7 
                 7 
                 — 
               
               
                   
               
            
           
         
       
     
     For the uplink and downlink configurations 1 to 6, the number of the uplink subframes is less than or equal to that of the downlink subframes. As such, one uplink subframe may return HARQ-ACK of PDSCHs in multiple downlink subframes. When the PUSCH of the uplink subframe is scheduled each time, the number of downlink subframes corresponding to HARQ-ACK returned by the uplink subframe is indicated by a UL DAI (representing an uplink no., similar to the UL index) in the PDCCH. After the UE learns the UL DAI information, PUSCH coding is performed on the HARQ-ACK of the PDSCH in a more efficient manner. The UL DAI and the UL Index correspond to a same field and contain two bits. When the HARQ process of the uplink/downlink data follows the timing of the uplink and downlink configuration 0, the two bits in the field are used as the UL Index. When the HARQ process of the uplink/downlink data follows the timing of the uplink and downlink configurations 1 to 6, the two bits in the field are used as the UL DAI. 
     In the FDD mode of the LTE system, a terminal receives downlink data in a subframe n−4, and returns signaling indicating whether the data on the downlink subframe needs to be retransmitted in the uplink subframe n. In other words, ACK/NACK information is returned, which is called Physical Downlink Shared Channel. Hybrid Automatic Repeat reQuest (PDSCHHARQ). 
     In order to make a moment at which data of terminals at different locations arrives at the base station is consistent with the timing of the base station, a timing advance (TA) is required when a terminal transmits data. A value of the TA is determined by a distance between the terminal and the base station. In a current LTE system, the maximum value of the TA is 0.67 ms, which is about 9-10 OFDM symbols. To ensure coverage of the base station and uplink synchronization, the terminal may support a current TA value range. 
     In the prior art, a TTI adopted by the LTE is generally 1 ms, which is consistent with the length of the subframe described above, so that it is easier to align in timing. With the development of technology, the LTE system begins to use a short TTI for communication. The length of the short TTI is generally 7 OFDM symbols or 2 OFDM symbols, which is less than the existing TTI length, i.e., 1 ms. When a communication system uses the short TTI to transmit a signal, the timing for the terminal to transmit an uplink signal is changed, which does not comply with the timing required by the current TA. When the signal is transmitted using the short TTI, the terminal transmits the uplink signal earlier than the prior art. In the case that the value of the TA is large, the terminal may not have enough time to process the data, thereby causing the terminal to fail to transmit the uplink signal. 
     SUMMARY 
     In an existing communication system, when TA is large, adopting a short TTI configuration may cause the terminal to have insufficient time to prepare transmitting of an uplink signal. Thus, the present disclosure provides a solution. 
     According to a first aspect of the present disclosure, a timing adjustment method is provided, including: 
     determining, by a base station, timing advance (TA) of a terminal; and 
     adjusting, by the base station according to the TA, a moment for the terminal to transmit an uplink signal. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station; 
     wherein the adjusting, by the base station according to the TA, a moment for the terminal to transmit the uplink data includes: 
     adjusting, by the base station according to the TA, a transmission time interval for the terminal to transmit the uplink data after receiving the uplink scheduling information, so that the terminal has enough time to process data before transmitting the uplink data. 
     In an embodiment, the uplink signal includes an acknowledgement (ACK) or a negative acknowledgement (NACK) of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and downlink data sent by the base station; 
     wherein the adjusting, by the base station according to the TA, a moment for the terminal to transmit the ACK/NACK includes: 
     adjusting, by the base station according to the TA, a transmission time interval for the terminal to transmit the ACK/NACK, so that the terminal has enough time to process data before transmitting the ACK/NACK. 
     In an embodiment, the adjusting, by the base station, a moment for the terminal to transmit the uplink data includes: 
     determining, by the base station, a time adjustment amount M for the terminal to transmit the uplink data, wherein the time adjustment amount M represents m transmission time intervals, indicates that the terminal transmits the uplink data after m transmission time intervals after receiving the uplink scheduling information, or indicates that the terminal transmits the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system, m is a positive integer; 
     transmitting, by the base station, adjustment information to the terminal through the uplink scheduling information, wherein the adjustment information comprises the time adjustment amount M. 
     In an embodiment, the adjusting, by the base station, a moment for the terminal to transmit the ACK/NACK includes: 
     determining, by the base station, a time adjustment amount P for the terminal to transmit the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals, indicates that the terminal transmits the ACK/NACK after p transmission time intervals after receiving the downlink scheduling information, or indicates that the terminal transmits the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system, p is a positive integer; 
     transmitting, by the base station, adjustment information to the terminal through the downlink scheduling information, wherein the adjustment information comprises the time adjustment amount P. 
     According to a second aspect of the present disclosure, a timing adjustment method is provided, including: 
     receiving, by a terminal, uplink scheduling information or downlink scheduling information transmitted by a base station; 
     transmitting, by the terminal, an uplink signal according to adjustment information of a moment for transmitting the uplink signal comprised in the uplink scheduling information or the downlink scheduling information. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to the uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station; 
     wherein the determining, by the terminal, the moment for transmitting the uplink data includes: 
     acquiring, by the terminal, the adjustment information of the moment for transmitting the uplink data according to the uplink scheduling information transmitted by the base station, and determining a time adjustment amount M for transmitting the uplink data, wherein the time adjustment amount M represents m transmission time intervals; 
     wherein the transmitting, by the terminal, the uplink data according to the adjustment information of the moment for transmitting the uplink data includes: 
     after the terminal receives the uplink scheduling information, transmitting, by the terminal according to the time adjustment amount M, the uplink data after m transmission time intervals; or, 
     transmitting, by the terminal according to the time adjustment amount M, the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system. 
     In an embodiment, the method further includes: after the terminal receives the uplink scheduling information, transmitting, by the terminal, the uplink data according to the time adjustment amount M and timing advance (TA). 
     In an embodiment, the uplink signal includes an acknowledgement (ACK) or a negative acknowledgement (NACK) of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and the downlink data transmitted by the base station; 
     wherein the transmitting, by the terminal, the uplink signal according to the adjustment information of the moment for transmitting the ACK/NACK includes: 
     acquiring, by the terminal, the adjustment information of the moment for transmitting the ACK/NACK according to the downlink scheduling information transmitted by the base station; and 
     determining, from the adjustment information, a time adjustment amount P for transmitting the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals; 
     wherein the transmitting, by the terminal, the uplink signal according to the adjustment information of the moment for transmitting the ACK/NACK includes: 
     after the terminal receives the downlink scheduling information, transmitting, by the terminal according to the time adjustment amount P, the ACK/NACK after p transmission time intervals; or, 
     transmitting, by the terminal according to the time adjustment amount P, the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system. 
     In an embodiment, the method further includes: after the terminal receives the downlink scheduling information, transmitting, by the terminal, the ACK/NACK of the downlink data according to the time adjustment amount P and timing advance (TA). 
     According to a third aspect of the present disclosure, a base station is provided, including: a determining module, configured to determine timing advance (TA) of a terminal; and an adjusting module, configured to adjust, according to the TA, a moment for the terminal to transmit an uplink signal. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station; 
     wherein the adjusting module includes: 
     a first adjusting sub-module, configured to adjust, according to the TA, a transmission time interval for the terminal to transmit the uplink data after receiving the uplink scheduling information, so that the terminal has enough time to process data before transmitting the uplink data. 
     In an embodiment, the uplink signal includes an acknowledgement (ACK) or a negative acknowledgement (NACK) of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and downlink data sent by the base station; 
     wherein the adjusting module includes: 
     a second adjusting sub-module, configured to adjust, according to the TA, a transmission time interval for the terminal to transmit the ACK/NACK, so that the terminal has enough time to process data before transmitting the ACK/NACK. 
     In an embodiment, the first adjusting sub-module includes: 
     a first determining unit, configured to determine a time adjustment amount M for the terminal to transmit the uplink data, wherein the time adjustment amount M represents m transmission time intervals, indicates that the terminal transmits the uplink data after m transmission time intervals after receiving the uplink scheduling information, or indicates that the terminal transmits the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system, m is a positive integer; 
     a first transmitting unit, configured to transmit adjustment information to the terminal through the uplink scheduling information, wherein the adjustment information comprises the time adjustment amount M. 
     In an embodiment, the second adjusting sub-module includes: 
     a second determining unit, configured to determine a time adjustment amount P for the terminal to transmit the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals, indicates that the terminal transmits the ACK/NACK after p transmission time intervals after receiving the downlink scheduling information, or indicates that the terminal transmits the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system, p is a positive integer; 
     a second transmitting unit, configured to transmit adjustment information to the terminal through the downlink scheduling information, wherein the adjustment information comprises the time adjustment amount P. 
     According to a fourth aspect of the present disclosure, a terminal is provided, including: 
     a receiving module, configured to receive uplink scheduling information or downlink scheduling information transmitted by a base station; 
     a transmitting module, configured to transmit an uplink signal according to adjustment information of a moment for transmitting the uplink signal comprised in the uplink scheduling information or the downlink scheduling information. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to the uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station; 
     wherein the receiving module includes: 
     a first receiving sub-module, configured to acquire the adjustment information of the moment for transmitting the uplink data according to the uplink scheduling information transmitted by the base station, and determine a time adjustment amount M for transmitting the uplink data, wherein the time adjustment amount M represents m transmission time intervals; 
     wherein the transmitting module includes: 
     a first transmitting sub-module, configured to transmit, after the terminal receives the uplink scheduling information and according to the time adjustment amount M, the uplink data after m transmission time intervals, or transmit, according to the time adjustment amount M, the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system. 
     In an embodiment, the first transmitting sub-module is further configured to transmit, after the terminal receives the uplink scheduling information, the uplink data according to the time adjustment amount M and timing advance (TA). 
     In an embodiment, the uplink signal includes an acknowledgement (ACK) or a negative acknowledgement (NACK) of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and the downlink data transmitted by the base station; 
     wherein the receiving module includes: 
     a second receiving sub-module, configured to acquire the adjustment information of the moment for transmitting the ACK/NACK according to the downlink scheduling information transmitted by the base station, and determine, from the adjustment information, a time adjustment amount P for transmitting the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals; 
     wherein the transmitting sub-module includes: 
     a second transmitting sub-module, configured to transmit, after the terminal receives the downlink scheduling information and according to the time adjustment amount P, the ACK/NACK after p transmission time intervals, or transmit, according to the time adjustment amount P, the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system. 
     In an embodiment, the second transmitting sub-module is configured to transmit, after the terminal receives the downlink scheduling information, the ACK/NACK of the downlink data according to the time adjustment amount P and timing advance (TA). 
     According to a fifth aspect of the present disclosure, a communication system is provided, including the above-described base station and the above-described terminal. 
     According to a sixth aspect of the present disclosure, a base station is provided, including: 
     a processor; 
     a storage, connected with the processor via a bus interface, and configured to store instructions and data required by the processor in performing operations; 
     a transceiver, configured to communicate with various other devices on a transmission medium; 
     wherein when the processor is called to execute the instructions and data stored in the storage, the base station performs following processing: 
     determining timing advance (TA) of a terminal; and 
     adjusting, according to the TA, a moment for the terminal to transmit an uplink signal. 
     According to a seventh aspect of the present disclosure, a terminal is provided, including: 
     a processor; 
     a storage, connected with the processor via a bus interface, and configured to store instructions and data required by the processor in performing operations; 
     a transceiver, configured to communicate with various other devices on a transmission medium; 
     wherein when the processor is called to execute the instructions and data stored in the storage, the terminal performs following processing: 
     receiving uplink scheduling information or downlink scheduling information transmitted by a base station; 
     transmitting an uplink signal according to adjustment information of a moment for transmitting the uplink signal comprised in the uplink scheduling information or the downlink scheduling information. 
     The beneficial effects of the present disclosure are described as follows. 
     Based on TA configuration in the existing communication system, the present disclosure adaptively adjusts the moment at which the terminal transmits the uplink signal, so that the terminal normally transmits the uplink signal required by the current TA timing under the short TTI transmission configuration. At the same time, the adjustment scheme of the present disclosure can also delay the moment for the terminal to transmit the uplink signal, thereby obtaining sufficient data processing time, and avoiding failure of transmission of the uplink signal resulting from processing data un-promptly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram illustrating frame structure of the TDD; 
         FIG. 2  is a schematic flowchart of a timing adjustment method of the present disclosure on a base station side; 
         FIG. 3  to  FIG. 5  are timing diagrams corresponding to a base station and a terminal according to the timing adjustment method of the present disclosure; 
         FIG. 6  is a schematic flowchart of a timing adjustment method of the present disclosure on a terminal side; 
         FIG. 7  is a schematic diagram illustrating structure of a base station of the present disclosure; 
         FIG. 8  is a schematic diagram illustrating structure of a terminal of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the technical problem, the technical solution, and the advantages of the present disclosure will be clearly described with reference to the accompanying drawings and embodiments. 
     When the TA of the communication system in the prior art is large and when the short TTI configuration is adopted, a terminal may have no processing capability to transmit an uplink signal. In view of this, the present disclosure provides a solution. 
     In one aspect, an embodiment of the present disclosure provides a timing adjustment method on a base station side, as shown in  FIG. 2 , including following operations. 
     At step  21 , a base station determines TA of a terminal. 
     At step  22 , the base station adjusts a moment for the terminal to transmit an uplink signal according to the TA. 
     The method in the embodiment dynamically adjusts the moment at which the terminal transmits the uplink signal according to the actual TA, so that the terminal may reasonably obtain sufficient data processing time to avoid the problem that the uplink signal is not transmitted due to insufficient processing capability of the terminal. 
     Further, in the embodiment, the short TTI is used for communication. According to the scheduling timing defined in the current LTE system, after receiving uplink scheduling information or downlink data, a terminal of which scheduling is on the short TTI may transmit the uplink signal earlier, which reduces the processing time of the terminal. For this reason, in the embodiment, the moment at which the terminal transmits the uplink signal may be delayed, which may provide sufficient processing time for the terminal, so as to avoid the failure of the transmission of the uplink signal. 
     The timing adjustment method of the present embodiment is exemplarily described below. 
     In practice, the uplink signal in the embodiment may be uplink data transmitted by the terminal to the base station in response to uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station. 
     During the entire transmission process, the base station firstly transmits the uplink scheduling information to the terminal. The terminal receives the uplink scheduling information, extracts scheduling information for transmitting uplink data, and then transmits the uplink data to the base station according to the scheduling information. Obviously, a transmission path of the process is base station→terminal→base station. Therefore, the corresponding TA is the sum of time consumed by transmitting the uplink scheduling information from the base station to the terminal and time consumed by transmitting the uplink data from the terminal to the base station. 
     As can be seen from the description in the background art, the embodiment delays the moment at which the terminal transmits the uplink data, so that the terminal has enough time to process data before transmitting the uplink data. 
     As a feasible implementation, the embodiment may determine a time adjustment amount M for the terminal to transmit the uplink data, where the time adjustment amount M represents m (m is a positive integer) transmission time intervals. 
     Then, the base station transmits adjustment information to the terminal through the uplink scheduling information, in which the adjustment information includes the time adjustment amount M. As such, the terminal may determine the time adjustment amount M according to the uplink scheduling information, and determine the moment at which the terminal transmits the uplink data according to the time adjustment amount M and the TA value. 
     It should be noted that in the embodiment, the role of the time adjustment amount M is to let the terminal determine delaying of the moment for the transmission of the uplink data. In practice, meanings of the time adjustment amount M in the embodiment are different, and may correspond to different values. 
     For example, the time adjustment amount M in the embodiment indicates that after receiving the uplink scheduling information, the terminal transmits the uplink data after m transmission time intervals. As shown in  FIG. 3 , assuming that TTIn is a transmission time interval for the terminal receiving the uplink scheduling information, it is determined that a theoretical transmission time interval for transmitting the uplink data is TTIn+m. The TTIn+m is the theoretical transmission time interval notified by the base station side. In practice, the terminal side may consider time consumed by path transmission, and may transmit the uplink data one TA in advance based on TTIx=n+m. It can be seen from  FIG. 3  that the distance between the base station and the terminal is D1, and a total transmission path of a signal is 2D1. As such, the transmission time interval actually transmitted by the terminal is to advance the transmission time interval consumed by the transmission in the 2D1 path. 
     For another example, the time adjustment amount M of the embodiment indicates that the terminal transmits the uplink data after m transmission time intervals based on the transmission time interval for transmitting the uplink data defined in the current LTE system. Then, when the UE adopts an FDD communication standard, assuming that the TTIn is the transmission time interval for the terminal receiving the uplink scheduling information, the theoretical transmission time interval for the terminal to transmit the uplink data is TTIn+4+m. Similarly, considering the time consumed by the path transmission, as shown in  FIG. 4 , the transmission time terminal for the terminal actually transmitting the uplink data may be one TA ahead of the theoretical transmission time interval TTIn+4+m (i.e., time consumed by transmission of the 2D1 path). Or, when the UE adopts a TDD communication standard, assuming that TTIn is the transmission time interval for the terminal receiving the uplink scheduling information, the theoretical transmission time interval of the uplink data that is finally delayed is TTIn+K+m (k is a fixed value, and corresponds to the uplink and downlink configuration adopted by TDD, referring to background art). As shown in  FIG. 5 , considering the time-consuming influence of the transmission path, the transmission time terminal for the terminal actually transmitting the uplink data may be one TA ahead of the theoretical transmission time interval TTIn+K+m (i.e., time consumed by transmission of the 2D1 path). 
     Obviously, it can be seen from the above description that technical solutions in which the terminal may determine the theoretical transmission time interval for transmitting the uplink data based on the time adjustment amount M belong to the protection scope of the present disclosure regardless of the definition of the time adjustment amount M and the value of m. 
     In addition, in practice, the uplink signal in the embodiment may also be an acknowledgement (ACK) or a negative acknowledgement (NACK) of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and the downlink data sent by the base station. 
     That is, during the entire transmission process, the base station firstly sends the downlink scheduling information and the downlink data to the terminal. The terminal receives the downlink scheduling information, extracts scheduling information for sending the ACK or NACK, and then sends the ACK or NACK to the base station according to the scheduling information. Obviously, a transmission path of the process is the base station→the terminal→the base station. Therefore, the corresponding TA is the sum of the time consumed by transmitting the downlink scheduling information from the base station to the terminal and the time consumed by transmitting the ACK or NACK from the terminal to the base station. 
     Correspondingly, the base station may determine, according to the size of the TA, a time adjustment amount P for the terminal to transmit the uplink data, where the time adjustment amount P represents p (p is a positive integer) transmission time intervals. 
     Then, the base station transmits adjustment information to the terminal through the downlink scheduling information, in which the adjustment information indicates the time adjustment amount P, so that the terminal may transmit the ACK or the NACK according to the time adjustment amount P and the TA in the adjustment information after receiving the downlink scheduling information. 
     It should be noted that in the embodiment, the role of the time adjustment amount P is to allow the terminal to determine a moment for transmitting the ACK or the NACK. In practice, meanings of the time adjustment amount P in the embodiment are different, and may correspond to different values. 
     For example, the time adjustment amount P in the embodiment indicates that after receiving the downlink scheduling information, the terminal transmits the ACK or the NACK after p transmission time intervals. Assuming that the TTIn is the transmission time interval for the terminal receiving the uplink scheduling information, the theoretical time interval for transmitting the uplink data is TTIn+p. 
     For another example, the time adjustment amount P of the embodiment indicates that the terminal transmits the ACK or the NACK after p transmission time intervals based on the transmission time interval for transmitting the uplink data defined in the current LTE system. When the UE adopts the FDD communication standard, assuming that the TTIn is the transmission time interval for the terminal receiving the uplink scheduling information, the theoretical transmission time interval of the transmitted uplink data is TTIx=n+k+p (k is a fixed value, and corresponds to the uplink and downlink configuration adopted by TDD). 
     It can be seen from the above description that the transmission time interval for the terminal actually transmitting the ACK or the NACK may be one TA ahead of the theoretical transmission time interval of the ACK or the NACK. 
     Similarly, technical solutions in which the terminal may determine the theoretical transmission time interval for transmitting the uplink data based on the time adjustment amount P belong to the protection scope of the present disclosure regardless of the definition of the time adjustment amount P and the value of p. 
     In another aspect, corresponding to the timing adjustment method on the base station side, another embodiment of the present disclosure further provides a timing adjustment method on the terminal side, as shown in  FIG. 6 . The method includes following operations. 
     At step  61 , a terminal receives uplink scheduling information or downlink scheduling information transmitted by a base station. 
     At step  62 , the terminal transmits an uplink signal according to adjustment information of a moment for transmitting the uplink signal included in the uplink scheduling information or the downlink scheduling information. 
     Obviously, the timing adjustment method on the terminal side of the present embodiment is applied to the timing adjustment method on the base station side. Therefore, the same advantageous effects as the timing adjustment method on the base station side may be achieved based on the timing adjustment method on the base station side. 
     As an exemplary example, the uplink signal in the embodiment includes uplink data transmitted from the terminal to the base station in response to the uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station. 
     In step  61 , the terminal acquires the adjustment information of the moment for transmitting the uplink data according to the uplink scheduling information transmitted by the base station, and determines, from the adjustment information, a time adjustment amount M for transmitting the uplink data. In this case, the time adjustment amount M represents m transmission time intervals. 
     Correspondingly, in step  62 , after the terminal receives the uplink scheduling information, the terminal transmits the uplink data after m transmission time intervals according to the time adjustment amount M. Alternatively, the terminal transmits, according to the time adjustment amount M, the uplink data after m transmission time intervals based on the transmission time interval for transmitting the uplink data defined in the current LTE system. 
     For example, when the terminal transmits the uplink data after m transmission time intervals according to the time adjustment amount M after the terminal receives the uplink scheduling information, assuming that TTIn is the transmission time interval for the terminal receiving the uplink scheduling information, a corresponding theoretical transmission time interval is TTIn+m. In practice, the terminal may consider the TA to transmit the uplink data. Therefore, the transmission time interval for actually transmitting the uplink data is one TA ahead of the theoretical transmission time interval TTIn+m. 
     For another example, when the terminal transmits, according to the time adjustment amount M, the uplink data after m transmission time intervals based on the transmission time interval for transmitting the uplink data defined in the current LTE system, and when the UE adopts the FDD communication standard, the theoretical transmission time interval for transmitting the uplink data is TTIx=n+4+m, and the transmission time interval for actually transmitting the uplink data is one TA ahead of TTIx=n+4+m. When the UE adopts the TDD communication standard, the theoretical time interval for transmitting the uplink data is TTIx=n+k+m (k is a fixed value, which corresponds to the uplink and downlink configuration adopted by TDD), and the transmission time interval for actually transmitting the uplink data is one TA ahead of TTIx=n+4+m. 
     In addition, as another exemplary example, the uplink signal in the embodiment may further include an ACK or a NACK of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and the downlink data sent by the base station. 
     Correspondingly, in step  61 , the terminal acquires adjustment information of a moment for transmitting the ACK or the NACK according to the downlink scheduling information sent by the base station, and determines a time adjustment amount P for transmitting the ACK or the NACK from the adjustment information. 
     Correspondingly, in step  62 , after the terminal receives the downlink scheduling information, the terminal transmits the ACK or the NACK after p transmission time intervals according to the time adjustment amount P. Alternatively, the terminal transmits, according to the time adjustment amount P, the ACK or the NACK after p transmission time intervals based on the transmission time interval for transmitting the ACK or the NACK defined in the current LTE system (the principle is the same as that of the method corresponding to the time adjustment amount M described above, which is not repeated herein). 
     Hereinafter, several embodiments of the timing adjustment method of the present disclosure are described in detail combining the timing adjustment method on the base station side and the timing adjustment method on the terminal side. 
     First Embodiment 
     In the first embodiment, a terminal UE adopts the FDD communication standard, and it is assumed that the time required for the terminal to process data is shortened according to the shortening of the short ITI. 
     It is assumed that after the terminal receives downlink scheduling information and downlink data at TTIn, the terminal is to transmit an ACK/NACK of the downlink data at TTIn+4, and the terminal is to transmit an uplink signal after 3 TTIs after receiving downlink scheduling information and downlink data. 
     Similar to scheduling timing of FDD in the LTE system, it is further assumed that the length of one TTI is 2 OFDM symbols, a transmission delay from the terminal UE to the base station is 2 OFDM symbols, and the length of the TA is the time domain length of 4 OFDM symbols (i.e., 2 short TTIs), which is approximately equal to 0.285 ms. 
     After the base station learns the TA, the base station may determine whether the UE has a processing capability for transmitting the ACK/NACK under the short TTI configuration. As an exemplary example, the determination process is described as follows. 
     The base station compares the TA with a preset threshold TA1. When the TA is greater than TA1, the moment for transmitting the ACK/NACK is to be adjusted. Otherwise, no adjustment is made, and the ACK/NACK is returned according to the scheduling timing defined in the current LTE system. 
     In practice, the UE may use TTIs with different lengths. In the embodiment, a TA1 may be respectively configured for the TTIs with different lengths. For example, in a short TTI, the processing time of the terminal is less, and a value of a corresponding TA1 is relatively small. In this case, the present embodiment may determine whether the terminal may transmit the ACK/NACK under the current TTI based on a reasonable evaluation criterion. 
     Obviously, in the embodiment, the TA is greater than TA1. As such, the base station determines that the terminal does not have the processing capability for transmitting the ACK/NACK according to the scheduling timing defined in the current LTE system, and then adjusts a transmission moment. In other words, the base station determines a time adjustment amount P, and transmits the time adjustment amount P to the terminal through the downlink scheduling information. 
     It is assumed that in the first embodiment, the time adjustment amount P indicates that the terminal transmits the ACK/NACK of the downlink data after p transmission time intervals based on the transmission time interval for transmitting the ACK/NACK defined in the LTE system. In this case, p is equal to 2, which is consistent with TA. 
     After the UE receives the downlink scheduling information and the downlink data, the base station is to receive the ACK/NACK of the downlink data on TTIn+4. The UE determines that the theoretical transmission time interval of the ACK/NACK is TTIn+4+2 according to the time adjustment amount P in the downlink scheduling information. The UE completes the transmission of the ACK/NACK based on the theoretical transmission time interval TTIn+4+2. 
     Alternatively, in the first embodiment, it is assumed that the time adjustment amount P indicates that the terminal transmits the ACK/NACK after p transmission time intervals after receiving the downlink scheduling information. In this case, p is equal to 6. 
     After receiving the downlink scheduling information, the UE consumes three TTIs to perform related processing, and determines, from the time adjustment amount P in the downlink scheduling information, that the theoretical transmission time interval of the ACK/NACK is TTIn+6. The UE completes the transmission of the ACK/NACK based on the theoretical transmission time interval TTIn+6. 
     By comparing the above two different definitions of the time adjustment amount P, it may be seen that the time that the terminal finally delays the transmission of the ACK/NACK is the same. 
     Second Embodiment 
     In the second embodiment, a terminal UE adopts the FDD communication standard, and it is assumed that the time required for the terminal to process data is shortened according to the shortening of the short TTI. 
     It is assumed that the terminal receives uplink scheduling information at subframe TTIn, transmits uplink data at TTIn+4, and transmits an uplink signal after 3 TTIs after receiving downlink scheduling information and downlink data. 
     Similar to scheduling timing of FDD in the LTE system, it is further assumed that the length of one TTI is 2 OFDM symbols, a transmission delay from the terminal UE to the base station is 2 OFDM symbols, and the length of the TA is the time domain length of 4 OFDM symbols (i.e., 2 short TTIs), which is approximately equal to 0.285 ms. 
     After the base station learns the TA, the base station may determine whether the UE has a processing capability for transmitting the uplink data under the TTI with such length. 
     It is assumed that in the embodiment, the base station determines that the terminal does not have the processing capability for transmitting the uplink data according to the scheduling timing defined in the current LTE system, and then adjusts a transmission moment. In other words, the base station determines a time adjustment amount M, and transmits the time adjustment amount M to the terminal through the uplink scheduling information. 
     It is assumed that in the embodiment, the time adjustment amount M indicates that the terminal transmits the uplink data after m transmission time intervals based on the transmission time interval for transmitting the uplink data defined in the current LTE system. In this case, m is equal to 2, which is consistent with TA. 
     After receiving the uplink scheduling information, it is assumed that the UE consumes three TTIs to perform related processing. The terminal determines, according to the time adjustment amount m in the uplink scheduling information, that the theoretical transmission time interval of the uplink data is TTIn+4+2, and completes the transmission of the uplink data based on the theoretical transmission time interval TTIn+4+2. 
     Alternatively, in the embodiment, it is assumed that the time adjustment amount M indicates that the terminal transmits the uplink data after m transmission time intervals after receiving the uplink scheduling information. In this case, m is equal to 6. 
     After receiving the uplink scheduling information, the UE consumes three TTIs to perform related processing. The UE determines, from the time adjustment amount m in the uplink scheduling information, that the theoretical transmission time interval of the uplink data is TTIn+6. The UE completes the transmission of the uplink data based on the theoretical transmission time interval TTIn+6. 
     Third Embodiment 
     In the third embodiment, a UE adopts the TDD communication standard. It is assumed that the time required for the terminal to process data is shortened according to the shortening of the short TTI, and the terminal transmits ACK/NACK of downlink data after 3 short TTIs after the terminal receives downlink scheduling DCI and the downlink data. 
     Since the number of uplink subframes and the number of downlink subframes in one radio frame configured for different subframe configurations in the TDD are different, subframe configuration is considered in addition to considering the time for the terminal to process data. That is, the base station indicates, in the downlink scheduling information, the feedback time of the ACK/NACK of the downlink data according to the time required by the terminal to process the data, the actual TA, and the subframe configuration. 
     In an example, a subframe adopts configuration no. 1 in Table 1. It is assumed that the length of the short TTI in the subframe is 2 OFDM symbols, and the terminal consumes at least three short TTIs to process data after receiving downlink scheduling information and downlink data. Assuming that the length of the TA is the time domain length of 4 OFDM symbols (i.e., two short TTIs), the terminal receives the downlink scheduling information and the downlink data at the first available short TTIn (n=1) in subframe 0. Then, according to the TA and the time required by the terminal to process the data, the terminal returns the downlink ACK/NACK at short TTIn+6. However, since the short TTIn+6=1+6=7 is in subframe 1 and the subframe 1 is a special subframe, a position corresponding to TTI 7 in this period is DwPTS, and an uplink channel may not be transmitted. Therefore, in the embodiment, the value of the time adjustment amount P needs to consider that the time interval for transmitting the ACK/NACK that is finally delayed falls on an uplink subframe. 
     As an example, the time adjustment amount P of the embodiment includes p=13 time intervals, indicating that the terminal delays 13 TTIs after receiving the downlink scheduling information. The time interval for the terminal to transmit the ACK/NACK is TTIn+13, which corresponds to an uplink subframe. 
     Fourth Embodiment 
     In the fourth embodiment, a UE adopts the TDD communication standard. It is assumed that the time required for the terminal to process data is shortened according to the shortening of the short TTI, and the terminal consumes 3 TTIs for related processing after receiving the uplink scheduling information. Since the number of uplink subframes and the number of downlink subframes in one radio frame configured for different subframe configurations in the TDD are different, subframe configuration is considered in addition to considering the time for the terminal to process data. 
     That is, the base station indicates, in the uplink scheduling information, the short TTI of transmission of the uplink data according to the time required by the terminal to process the data, the actual TA, and the subframe configuration. 
     In an example, a subframe adopts configuration no. 1 in Table 1. It is assumed that the length of the short TTI in the subframe is 2 OFDM symbols, and the terminal consumes at least three short TTIs to process data after receiving the uplink scheduling information. Assuming that the length of the TA is the time domain length of 4 OFDM symbols (i.e., two short TTIs), the terminal receives the uplink scheduling information at the first available short TTIn (n=1) in subframe 0. Then, according to the TA and the time required by the terminal to process the data, the terminal transmits the uplink data at short TTIn+6. 
     However, since the short TTIn+6=1+6=7 is in subframe 1 and the subframe 1 is a special subframe, a position corresponding to TTI 7 in this period is DwPTS, and an uplink channel may not be transmitted. Therefore, in the embodiment, the value of m needs to consider that the time interval for the terminal to transmit the uplink data falls on an uplink subframe. 
     As an example, the time adjustment amount M of the embodiment includes m=13 time intervals, indicating that the terminal delays 13 TTIs after receiving the downlink scheduling information. The time interval for the terminal to transmit the ACK/NACK is TTIn+13, which corresponds to an uplink subframe. 
     It should be noted that in the first embodiment to the fourth embodiment, the time domain length of the short TTI is 2 OFDM symbols. The time domain length of the short TTI may be 7 OFDM symbols or 3 OFDM symbols or 4 OFDM symbols. The time required by the terminal to process the data after receiving the downlink scheduling information and the downlink data or the uplink scheduling information may be defined as other time, such as five short TTIs. The processing time is related to the capability of the terminal, which is not limited in the present disclosure. In addition, the present disclosure does not limit how the base station determines whether the terminal has the processing capability of transmitting an uplink signal under the current TA and TTI value. 
     Correspondingly, an embodiment of the present disclosure further provides a base station, as shown in  FIG. 7 . The base station includes: 
     a determining module, configured to determine TA of a terminal; and 
     an adjusting module, configured to adjust, according to the TA, a moment for the terminal to transmit an uplink signal. 
     The base station in the embodiment dynamically adjusts the moment at which the terminal transmits the uplink signal according to the actual TA, so that the terminal may reasonably obtain sufficient data processing time to avoid the problem that the uplink signal is not transmitted due to insufficient processing capability of the terminal. 
     Specifically, the determining module in the embodiment may delay the moment at which the terminal transmits the uplink signal according to the TA. 
     The delay scheme of the uplink signal is described in detail below. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station. 
     The adjusting module includes: 
     a second receiving sub-module, configured to acquire the adjustment information of the moment for transmitting the ACK/NACK according to the downlink scheduling information transmitted by the base station, and determine, from the adjustment information, a time adjustment amount P for transmitting the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals; 
     a first adjusting sub-module, configured to adjust, according to the TA, a transmission time interval for the terminal to transmit the uplink data after receiving the uplink scheduling information, so that the terminal has enough time to process data before transmitting the uplink data. 
     Specifically, the first adjusting sub-module includes: 
     a first determining unit, configured to determine a time adjustment amount M for the terminal to transmit the uplink data, wherein the time adjustment amount M represents m transmission time intervals, indicates that the terminal transmits the uplink data after m transmission time intervals after receiving the uplink scheduling information, or indicates that the terminal transmits the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system, m is a positive integer; 
     a first transmitting unit, configured to transmit adjustment information to the terminal through the uplink scheduling information, wherein the adjustment information comprises the time adjustment amount M. 
     In another embodiment, the uplink signal includes an ACK or a NACK of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and downlink data sent by the base station. 
     The adjusting module includes: 
     a second adjusting sub-module, configured to adjust, according to the TA, a transmission time interval for the terminal to transmit the ACK/NACK, so that the terminal has enough time to process data before transmitting the ACK/NACK. 
     The second adjusting sub-module includes: 
     a second determining unit, configured to determine a time adjustment amount P for the terminal to transmit the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals, indicates that the terminal transmits the ACK/NACK after p transmission time intervals after receiving the downlink scheduling information, or indicates that the terminal transmits the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system, p is a positive integer; 
     a second transmitting unit, configured to transmit adjustment information to the terminal through the downlink scheduling information, wherein the adjustment information comprises the time adjustment amount P. 
     Obviously, the base station in the present embodiment corresponds to the timing adjustment method on the base station side described above. Therefore, the same technical effects as the timing adjustment method on the base station side may be achieved. 
     Correspondingly, an embodiment of the present disclosure further provides a terminal, as shown in  FIG. 8 . The terminal includes: 
     a receiving module, configured to receive uplink scheduling information or downlink scheduling information transmitted by a base station; 
     a transmitting module, configured to transmit an uplink signal according to adjustment information of a moment for transmitting the uplink signal comprised in the uplink scheduling information or the downlink scheduling information. 
     Obviously, the terminal in the present embodiment corresponds to the timing adjustment method on the base station side described above. Therefore, the same advantageous effects as the timing adjustment method on the base station side may be achieved based on the timing adjustment method on the base station side. 
     In an embodiment, the uplink signal includes uplink data transmitted by the terminal to the base station in response to the uplink scheduling information after the terminal receives the uplink scheduling information transmitted by the base station. 
     The receiving module includes: 
     a first receiving sub-module, configured to acquire the adjustment information of the moment for transmitting the uplink data according to the uplink scheduling information transmitted by the base station, and determine a time adjustment amount M for transmitting the uplink data, wherein the time adjustment amount M represents m transmission time intervals. 
     The transmitting sub-module includes: 
     a first transmitting sub-module, configured to transmit, after the terminal receives the uplink scheduling information and according to the time adjustment amount M, the uplink data after m transmission time intervals, or transmit, according to the time adjustment amount M, the uplink data after m transmission time intervals based on a transmission time interval for transmitting the uplink data defined in a current LTE system. 
     Specifically, the first transmitting sub-module is further configured to transmit, after the terminal receives the uplink scheduling information, the uplink data according to the time adjustment amount M and TA. 
     In another embodiment, the uplink signal includes an ACK or a NACK of downlink data returned by the terminal to the base station after the terminal receives downlink scheduling information and the downlink data transmitted by the base station. 
     The receiving module includes: 
     a second receiving sub-module, configured to acquire the adjustment information of the moment for transmitting the ACK/NACK according to the downlink scheduling information transmitted by the base station, and determine, from the adjustment information, a time adjustment amount P for transmitting the ACK/NACK, wherein the time adjustment amount P represents p transmission time intervals. 
     The transmitting sub-module includes: 
     a second transmitting sub-module, configured to transmit, after the terminal receives the downlink scheduling information and according to the time adjustment amount P, the ACK/NACK after p transmission time intervals, or transmit, according to the time adjustment amount P, the ACK/NACK after p transmission time intervals based on a transmission time interval for transmitting the ACK/NACK defined in a current LTE system. 
     Specifically, the second transmitting sub-module is configured to transmit, after the terminal receives the downlink scheduling information, the ACK/NACK of the downlink data according to the time adjustment amount P and TA. 
     Obviously, the terminal in the present embodiment corresponds to the timing adjustment method on the terminal side described above. Therefore, the same technical effects as the timing adjustment method on the terminal side may be achieved. 
     In addition, the present disclosure also provides a communication system including the above-described base station and the above-described terminal. Obviously, based on the base station and the terminal provided by the present disclosure, when the communication system is configured with a short TTI, the terminal farther from the base station may normally transmit an uplink signal, which also meets a timing requirement of current TA. 
     The foregoing are several embodiments of the present disclosure. It should be noted that, for persons having ordinary skill in the art, various improvements and retouches, which are made without departing from the principle of the present disclosure, should be covered by the present disclosure.