WO2012048570A1 - Uplink emission timing control method and device in long term evolution (lte) system - Google Patents

Abstract

An uplink emission timing control method in the Long Term Evolution (LTE) system is disclosed in the present invention. The method includes the steps of: setting an accumulation adjusting amount; tracing a downlink reception boundary, updating the accumulation adjusting amount according to the adjusting amount for adjusting the downlink reception boundary for each time, and adjusting an uplink emission boundary according to the current accumulation adjusting amount when adjusting the uplink emission boundary; dynamically monitoring whether there is an Time Advance (TA) command sent by a Base Station (BS) needed to be executed, if yes, adjusting the uplink emission boundary according to the TA command in priority, and resetting the accumulation adjusting amount. By means of tracing and adjusting the downlink reception boundary, performing corresponding uplink emission boundary adjusting according to the accumulation adjusting amount, and simultaneously dynamically monitoring whether there is a TA command needed to be executed, if yes, executing the TA command in priority, thereby the present invention ensures that the offset value between the uplink emission boundary and the downlink reception boundary is the value expected by the BS, and ensures successful reception by the BS in a better way.

Description

 Uplink transmission timing control method and device in LTE system

 The present invention relates to the field of wireless communications, and in particular, to an uplink transmit timing control method and apparatus in a Long Term Evolution (LTE) system. Background technique

 In the LTE system, the uplink uses single carrier frequency division (SC-FDMA) multiple access technology, which requires different user terminal (UE) uplink data to reach the base station (eNB) within the cyclic prefix (CP) length as much as possible. To ensure orthogonality between different UEs, the LTE system guarantees/limits the uplink transmission time from the following aspects:

 First, the UE's transmission has a Timing Advance (TA) relative to the reception. The timing advance TA is related to the distance between the UE and the eNB. The TA actually reflects the Round Trip Delay (RTD). . The eNB performs uplink transmission timing control by adjusting the TA of each UE according to the reception timing estimation; the TA adjustment command in the LTE is transmitted to the UE through the medium access control MAC signaling manner. The schematic diagram of the uplink emission boundary adjustment by TA is shown in Figure 1:

In terms of protocol, the advance of the transmit (uplink) timing relative to the receive (downlink) timing is expressed as: (NTA + NTA offset) ^x Ts; where in the frequency division duplex FDD system, N _TA . _Ffset =0; Under the time division duplex TDD system, N _TA . _Ffset =624, used to _reserve the uplink and downlink conversion interval of about 20 us; N _TA is adjusted by the eNB through the TA command; In the protocol, the TA adjustment has the following timing constraints: For the nth subframe The obtained TA command requires that the corresponding transmission timing adjustment be performed in the subframe n+6, and if the transmission of the n+6th subframe overlaps with the n+5th subframe due to the adjustment of the transmission timing, the UE completely transmits. The n+5th subframe does not transmit the beginning overlap of the n+6th subframe. Secondly, in addition to responding to the TA command of the eNB, the UE completes the uplink transmission boundary adjustment at the specified timing, and also needs to handle the automatic autonomous tracking caused by the downlink reception timing change; usually, in order to ensure downlink reception Performance, after the initial cell search finds the downlink reception boundary, the receiver of the UE needs to be able to continuously track and update the downlink reception boundary, and since (N _TA + N _{TA ffset} ) x Ts represents "transmission (uplink) timing) The advancement amount TA" with respect to the reception (downlink) timing, and the value of the base station is unchanged before the base station transmits the TA command. Therefore, if the downlink reception boundary is changed, if the uplink-downward advance amount TA is not adjusted, This will cause the UE uplink transmission timing to continuously follow the downlink reception boundary change and quickly hop, which will bring great trouble to the reception of the eNB. The automatic uplink timing tracking is triggered by the change of the downlink reception timing. The tracking frequency and amplitude are also limited in the protocol:

 Each individual adjustment step does not exceed Tq;

Minimum adjustment rate: Adjust at least 7*T _S per second;

 Maximum adjustment rate: Adjust Tq at most every 200ms.

 In the prior art, the adjustment of the foregoing two aspects is performed separately, and the uplink adjustment period of the uplink transmission boundary is generally selected to be 200 ms, and the corresponding maximum adjustment step size is Tq, so that the processing exists in different channel environments as follows. The problem is that when the uplink transmission boundary is frequently changed in the high-speed mobile environment, when the uplink adjustment period is selected as 200ms, the change of the uplink transmission boundary cannot be quickly tracked, and the uplink advance timing TA cannot be adjusted in time. The UE uplink transmission timing continuously follows the downlink reception boundary change and rapidly hops, which causes great trouble for the eNB receiving; when in the static or low-speed mobile environment, the uplink transmission boundary is unchanged or the transition period is very long. In the large case, when the selection period is 200ms, the overhead of the system may be increased, and the energy consumption of the device is wasted. Summary of the invention

The main technical problem to be solved by the present invention is to provide an uplink transmission timing control method and apparatus in an LTE system, which can track and adjust the downlink reception boundary, and obtain the tracking result according to the tracking. During the adjustment of the corresponding uplink adjustment boundary, the current advance adjustment amount is dynamically monitored by the time advance command sent by the base station to better ensure the smooth reception of the base station.

 To solve the above technical problem, the present invention provides an uplink transmission timing control method in an LTE system, including: setting a cumulative adjustment amount; the method includes the following steps:

 Tracking the downlink receiving boundary, updating the accumulated adjustment amount according to the adjustment amount adjusted for each downlink receiving boundary, and performing uplink transmission boundary adjustment according to the current accumulated adjustment amount when the uplink transmission boundary is adjusted;

 Dynamically monitoring whether there is a time advance command sent by the base station needs to be executed, and then preferentially performing uplink transmission boundary adjustment according to the time advance command, and clearing the accumulated adjustment amount.

 In an embodiment of the present invention, the uplink transmission boundary is adjusted according to the current cumulative adjustment amount to: perform an uplink boundary adjustment at a periodic point of a preset uplink adjustment period, where the uplink adjustment period includes At least one level.

 In an embodiment of the present invention, the downlink receiving boundary is adjusted to: perform downlink receiving boundary adjustment at a periodic point of a preset downlink adjustment period;

 The dynamically monitoring whether there is a time advance command sent by the base station needs to be performed as follows: determining whether the period of the uplink adjustment period and the period of the downlink adjustment period arrive before or at the same time.

 When the uplink adjustment period includes multiple levels, different levels of uplink adjustment periods correspond to different maximum adjustment steps.

 In an embodiment of the present invention, the ratio of the maximum adjustment step size corresponding to the uplink adjustment period of each level other than the highest level to the maximum adjustment step size corresponding to the highest level uplink adjustment period, and the highest level The other aspects of the uplink adjustment period are the same as the highest level of the uplink adjustment period.

In an embodiment of the present invention, when the uplink adjustment period is the highest level uplink adjustment period, the corresponding maximum adjustment step size is an absolute adjustment step; When the value is 1/2, 1/4, and 1/8 of the highest-level uplink adjustment period, the maximum adjustment step corresponding to the maximum adjustment step is 1/2, 1/4, and 1 of the absolute adjustment step. /8.

 In an embodiment of the present invention, the method further includes: selecting, according to an adjustment frequency of the uplink transmission boundary of different channels, the uplink adjustment period corresponding thereto.

 In an embodiment of the present invention, the uplink transmission boundary is adjusted according to the current accumulated adjustment amount to: determine whether the accumulated adjustment amount is greater than a maximum adjustment step of the uplink adjustment period, and if not, The adjustment amount of the uplink emission boundary adjustment is directly the cumulative adjustment amount, and the accumulated adjustment amount is cleared; if yes, the adjustment amount of the uplink emission boundary adjustment is the maximum adjustment step size, and the cumulative adjustment amount corresponds to The step of determining the cumulative adjustment amount is repeated when the cycle point of the next uplink adjustment period comes.

 An uplink transmission timing control apparatus in an LTE system, comprising: a downlink reception boundary tracking adjustment module, an uplink transmission boundary adjustment module, and a timing advance command processing module; wherein the downlink reception boundary tracking adjustment module is used for tracking a downlink receiving boundary, updating the preset cumulative adjustment amount according to the adjustment amount adjusted for each downlink receiving boundary, and transmitting the accumulated adjustment amount to the uplink transmitting boundary adjustment module; the uplink transmitting boundary adjustment module, And performing, according to the current accumulated adjustment amount obtained by tracking the downlink receiving boundary, performing corresponding uplink transmission boundary adjustment; the time advance command processing module is configured to dynamically monitor whether a time advance command needs to be executed, and the priority is based on The timing advance command commands an uplink transmission boundary adjustment and clears the accumulated adjustment amount.

 In an embodiment of the present invention, the uplink transmission boundary adjustment module performs the uplink transmission boundary adjustment according to the cumulative adjustment amount, which is performed at a periodic point of a preset uplink adjustment period, where the uplink adjustment period includes At least one level.

 In an embodiment of the present invention, the downlink receiving boundary adjustment performed by the downlink receiving boundary tracking adjustment module is performed at a periodic point of a preset downlink adjustment period;

The timing advance command processing module is further configured to dynamically monitor whether there is a base station sending The time advance command needs to be executed before determining whether there is a periodic point of the uplink adjustment period and a period point of the downlink adjustment period before or at the same time.

 In an embodiment of the present invention, when the uplink adjustment period includes multiple levels, the uplink adjustment periods of different levels correspond to different maximum adjustment step sizes.

 In an embodiment of the present invention, the ratio of the maximum adjustment step size corresponding to the uplink adjustment period of each level other than the highest level to the maximum adjustment step size corresponding to the highest level uplink adjustment period, and the highest level The other aspects of the uplink adjustment period are the same as the highest level of the uplink adjustment period.

 In an embodiment of the present invention, when the uplink transmission boundary adjustment module performs uplink transmission boundary adjustment according to the accumulated adjustment amount, it is determined whether the cumulative adjustment amount is greater than the maximum adjustment of the corresponding uplink adjustment period. Step size, if not, the adjustment amount of the uplink emission boundary adjustment is directly the cumulative adjustment amount, and clears the accumulated adjustment amount; if yes, the adjustment amount of the uplink emission boundary adjustment is the maximum adjustment step size The cumulative adjustment amount correspondingly decreases the maximum adjustment step size, and when the cycle point of the next uplink adjustment period comes, the operation of determining the accumulated adjustment amount is repeated.

 The beneficial effects of the present invention are as follows: The present invention performs tracking adjustment on the downlink receiving boundary, and accumulates each adjustment amount to obtain a cumulative adjustment amount. When the periodic point of the uplink adjustment period arrives, the corresponding cumulative adjustment amount is performed according to the current cumulative adjustment amount. Uplink emission boundary adjustment; and during the above cycle, dynamically monitoring whether there is a time advance command to be executed, if yes, prioritizing the uplink emission boundary according to the time advance command, and clearing the accumulated adjustment amount, thereby ensuring The value of the time advance of the uplink transmission boundary with respect to the downlink reception boundary is a value expected by the base station to better ensure the smooth reception of the base station. DRAWINGS

1 is a schematic diagram of the principle of uplink transmission timing control according to an embodiment of the present invention; FIG. 2 is an overall block diagram of an embodiment of the present invention; FIG. 3 is a flowchart of downlink receiving boundary tracking adjustment according to an embodiment of the present invention; FIG.

 FIG. 4 is a flowchart of automatically adjusting an uplink transmission boundary according to an embodiment of the present invention; FIG.

 FIG. 5 is a flowchart of processing a time advance command according to an embodiment of the present invention; FIG.

 Figure 6 is an overall detailed flow chart of an embodiment of the present invention. detailed description

 In the LTE system, since the uplink uses the single-carrier frequency division SC-FDMA multiple access technology, it is required that different UE uplink data can reach the eNB within the CP length as much as possible to ensure orthogonality between different UEs. Therefore, the LTE system needs to guarantee/limit the uplink transmission time from two aspects: First, the TA command sent by the eNB adjusts the uplink (TX) transmission boundary of the UE side, and secondly, the UE side needs to continuously track the downlink (RX). The receiving boundary, when it is found that there is a change in the RX boundary, it is also necessary to actively adjust the TX boundary; therefore, in order to better ensure the smooth reception of the eNB, the above two aspects need to be organically combined, and flexible for different channel environments. Choose to adjust the parameters to meet their different performance needs.

 The present invention will be further described in detail with reference to the accompanying drawings in which: FIG.

 An embodiment of the method of the present invention comprises the following steps:

 Set the cumulative adjustment amount;

 Tracking the downlink receiving boundary, updating the accumulated adjustment amount according to the adjustment amount adjusted for each downlink receiving boundary, and performing uplink transmission boundary adjustment according to the current accumulated adjustment amount when the uplink transmission boundary is adjusted;

Dynamically monitoring whether there is a time advance command sent by the base station needs to be executed. If yes, the uplink emission boundary adjustment is preferentially performed according to the time advance command, and the accumulated adjustment amount is cleared, and the initial dynamic accumulation amount can be set to zero. ; Performing the uplink transmission boundary adjustment according to the current accumulated adjustment amount is performed at a periodic point of the preset uplink adjustment period; where the uplink adjustment period includes at least one level, and when the uplink adjustment period includes multiple levels, different levels The uplink adjustment period corresponds to different maximum adjustment step sizes; for example, the ratio of the maximum adjustment step size corresponding to the uplink adjustment period of each level other than the highest level to the maximum adjustment step size corresponding to the highest level uplink adjustment period, and The ratio of the uplink adjustment period of each level other than the highest level to the highest level of the uplink adjustment period may be the same; the specific one may be as follows: When the uplink adjustment period is the highest level of the uplink adjustment period, the corresponding maximum adjustment step When the value of the uplink adjustment period is 1/2, 1/4, and 1/8 of the highest level uplink adjustment period, the maximum adjustment step corresponding to the maximum adjustment step is the absolute adjustment step. Long 1/2, 1/4, and 1/8; For example: The highest level of the upstream adjustment period takes 200 milliseconds When the corresponding adjustment step is the absolute adjustment step length Tq; when the value of the uplink adjustment period is 1/2, 1/4, and 1/8 of 200 milliseconds, the corresponding maximum adjustment step length may be Tq /2, Tq/4, and Tq/8; Of course, according to actual needs, the uplink adjustment period can also be flexibly selected as other ratio values of 200 milliseconds, and the corresponding maximum adjustment step size is selected as the ratio corresponding to the absolute adjustment step size Tq. The value, for example, when the uplink adjustment period is 3/4 of 200 milliseconds, the corresponding maximum adjustment step size can be 3*Tq/4.

 The downlink receiving boundary adjustment is performed at a periodic point of the preset downlink adjustment period. The monitoring of whether there is a time advance command sent by the base station needs to be performed to determine whether there is a periodic point of the uplink adjustment period and the downlink adjustment period. Before the cycle point arrives or is performed at the same time, of course, according to the actual needs of the system, whether or not the TA command needs to be performed for real-time monitoring can be monitored at any time.

The value of the uplink adjustment period is selected according to the adjustment frequency of the uplink transmission boundary of the different channel environment, and the adjustment frequency of the uplink transmission boundary may also be set to include at least one level, and the level thereof corresponds to the level of the uplink adjustment period. When the adjustment frequency of the uplink transmission boundary falls within a preset level, the uplink boundary adjustment period of the corresponding level is selected, for example, the uplink is uplinked. The adjustment frequency of the transmission boundary can also be divided into four levels corresponding to the above uplink adjustment period according to the actual situation of the system. When the adjustment frequency of the uplink transmission boundary falls within the level with the largest adjustment frequency, the corresponding uplink adjustment period is selected. The minimum upstream adjustment period allows fast tracking of the upstream transmit boundary and adjusts accordingly.

 When the uplink transmission boundary adjustment is performed according to the cumulative adjustment amount, it is determined whether the cumulative adjustment amount is greater than a maximum adjustment step of the uplink adjustment period: If not, the adjustment amount of the uplink transmission boundary adjustment is directly the cumulative adjustment amount And clearing the accumulated adjustment amount; if yes, the adjustment amount of the uplink transmission boundary adjustment is the maximum adjustment step length, and the cumulative adjustment amount correspondingly decreases the maximum adjustment step length, in the next uplink adjustment period Repeat the above steps when the cycle point arrives.

 When it is detected that there is a time advance command to be executed, the time advance command is executed preferentially, and the accumulated adjustment amount is cleared.

 The method of the present invention is illustrated below from a specific example:

 See Figure 3 for the RX boundary tracking adjustment process. Due to the uplink (TX) transmission timing, the following line (RX) reception timing is always referenced. Therefore, it is necessary to track and obtain a more accurate RX boundary to accurately adjust the TX. boundary. In the initial synchronization process, an initial cell search using the PSS/SSS (synchronization signal/secondary synchronization signal) signal can obtain an initial RX boundary called "coarse synchronization"; subsequently, the downlink reception opportunity is continuously based on the downlink The reference signal (RS) is used for channel estimation. In this process, the RX boundary can be further fine-tuned, which is called "precision synchronization". At the same time, for the sake of concise expression, the following physical quantities can be designed:

 System absolute time MRTR;

 The offset of the RX boundary from the absolute time of the system RX_offset;

 The actual offset of the uplink transmit boundary and the downlink receive boundary TX_offset;

 RX boundary adjustment period RX_tracking_period;

Adjustment amount Adjust-value; The cumulative adjustment is Adjust-accumulated.

 The adjustment amount Adjust_value described above is an adjustment amount for each adjustment of the RX reception boundary. The downlink reception timing can be obtained by MRTR and RX_offset, which can be used as the boundary of the radio frequency (RF). For the Adjust_value, when the cycle point of RX_tracking_period arrives, it will be directly adjusted to RX_offset each time; meanwhile, due to the adjustment of the TX boundary It can only be performed at the TX adjustment cycle point. In order to ensure that each adjustment of RX_offset does not immediately affect the adjustment of the TX boundary, TX_offset needs to be updated accordingly, that is, Adjust_value is added; Adjust-accumulated is accumulated by Adjust_value, mainly For the subsequent TX adjustment service; it should be noted that the initial value of RX_offset is obtained by the "rough synchronization" process, and the initial value of Adjust-accumulated is set to 0; RX_tracking_period can be flexibly designed according to the performance required by the system.

 See Figure 4 for a flowchart of automatic adjustment of the TX boundary; TX automatically adjusts the boundary based on the Adjust-accumulated resulting from the adjustment of the tracking RX boundary. Similarly, the following physical quantities can be designed:

 The actual offset of the uplink transmit boundary and the downlink receive boundary TX_offset;

 The expected offset of the uplink transmit boundary and the downlink receive boundary controlled by the TA command TX_target; TX adjustment period TX_tracking_period;

 During each TX adjustment period, adjust the value: Tq'.

 For Tq', in order to meet the maximum adjustment rate in the protocol: "Maximum adjustment frequency of Tq per 200ms", the level of the upstream adjustment period can be designed as the following table:

Among them, the value of Tq, the agreement has the following requirements: Downlink bandwidth (MHz) Tq

 1.4 16*Ts

 3 8*Ts

 5 4*Ts

> 10 2*Ts As mentioned earlier, the LTE protocol has clear requirements for tracking frequency and amplitude. According to the "maximum adjustment rate: the maximum adjustment of Tq per 200ms" limit, a table is designed to enable TX_tracking_period and Tq' Correct matching can not only meet the requirements of adjusting the frequency, but also effectively control the TX boundary tracking adjustment frequency by using different corresponding items in the table. Of course, according to actual needs, other proportions of uplink adjustment period can also be set to meet the system. Performance needs. According to the above table, in the actual environment, the parameter can be flexibly configured to meet actual needs. For example, the adjustment frequency of the uplink transmission boundary for different systems can also be divided into four corresponding to the above TX_tracking_period according to the actual situation of the system. Level, when the adjustment frequency of the uplink transmission boundary falls within the level with the largest adjustment frequency, the corresponding TX_tracking_period selects the minimum level of the uplink adjustment period, so that the downlink reception boundary can be quickly tracked and adjusted accordingly. Of course, the user can also select according to the actual situation of the system. In the environment where the uplink transmission boundary frequently hops (such as in a high-speed mobile environment), a smaller TX_tracking_period can be selected to reach the fast and accurate tracking of the uplink transmission boundary. In the environment where the uplink transmission boundary is infrequently hopping (such as in a static environment), a larger TX_tracking_period can be selected to reduce the processing overhead of the device and save power; meanwhile, to meet "each individual adjustment" The step size does not exceed the Tq" limit. After using the designed table, it becomes "each individual adjustment step does not exceed Tq'". Correspondingly, when the cycle point of TX_tracking_period arrives, the RX is adjusted in TX_tracking_period. Adjust-accumulated to judge, if it is greater than Tq', it needs to complete the uplink emission boundary adjustment multiple times, each adjustment amount is Tq ', the corresponding Adjust-accumulated decrease Tq ', the updated Adjust_accumulated repeats the above steps when the cycle point of TX_tracking_period arrives; if it is less than Tq' (this may have been adjusted more than once, or the RX boundary adjustment is small), then it is directly adjusted to the eNB expectation The uplink and downlink receive boundary offset (TX_target); thus, the TX transmission boundary can be constantly fine-tuned, so that the eNB can continuously maintain uplink synchronization, and finally adjust the TX transmission boundary to the time desired by the eNB.

 Referring to the flowchart of the TA command processing of FIG. 5, it is unpredictable for the UE to issue the TA command when compared with the "automatic uplink timing tracking caused by the downlink receiving timing change", and the priority of the TA command is compared. Higher, so when performing the above steps, when the TA command is detected, the TA command must be executed first, and Adjust-accumulated is cleared. Similarly, for a clearer description, the following physical quantities can be defined:

 Upstream transmit advance command (value) TX_cmd.

 Each subframe needs to determine whether it is currently required to execute the TA command; once a TA command needs to be performed in this subframe, the TX_offset (accumulated by TX_cmd) is directly adjusted to the eNB's desired uplink and downlink reception boundary offset value (TX_target), and Regardless of whether there is a need to adjust the TX emission boundary due to the RX boundary adjustment and affecting the TX, the Adjust-accumulated is cleared to Adjust-accumulated=0, which also reflects the higher priority of the TA command. It should be noted that, in the protocol, it is required that for the TA command received in the nth subframe, the corresponding transmission timing adjustment is performed in the subframe n+6, and if the transmission timing is adjusted, the n+6th subframe is caused. If the transmission overlaps with the n+5th subframe, the UE completely transmits the n+5th subframe without transmitting the first overlapping portion of the n+6th subframe; and in the nth subframe to the n+5th subframe The time gap does not affect the RX receive boundary tracking adjustment and the TX transmit boundary automatic adjustment.

Please refer to FIG. 6 for an overall detailed flowchart of an embodiment of the present invention, which is specifically as follows: Initially, the accumulated adjustment amount Adjust_accumulated is set to 0; when each subframe arrives, it is determined whether a TA command needs to be executed, If yes, execute the TA command and perform uplink transmit boundary adjustment according to the TA command, that is, directly TX_offset (accumulate TX_cm by TX_target) = TX_target+TX_cmd ) Adjust to the desired uplink and downlink receive boundary offset value ( ΤΧ — target ) of the eNB and clear Adjust—accumulated to Adjust—accumulated=0. If there is no TA command to be executed, determine whether the cycle point of RX_tracking_period is Arrival, if it arrives, RX's receiving boundary adjustment according to Adjust_value, that is, RX_offset is updated to RX_offset+Adj ust_value, and Adj ust_accumulated=Adj ust_accumulated+ Adjust_value, in order to ensure that each adjustment of RX_offset does not immediately affect the adjustment of the TX boundary, TX_offset is also updated accordingly, ie TX_offset=TX_offset + Adjust_value; If the cycle point of RX_tracking_period does not arrive, the reception boundary of RX is not adjusted, and it is determined whether the cycle point of TX_tracking_period arrives, and if it arrives, TX is based on Adjust-accumulated The value of the TX emission boundary is adjusted as follows: Adjust_accumulated < Tq , directly adjust TX_target to TX_target + Adjust-accumulated', when Adjust-accumulated > Tq, adjust TX_target to TX_target+Tq ' The Adjust-accumulated is updated to Ad just-accumulated - Tq , and the updated Adjust-accumulated repeats the above steps when the cycle point of the next TX_tracking _period arrives. When the cycle point of TX_tracking_period does not arrive, the TX emission boundary is not adjusted. .

 An embodiment of the device of the present invention includes a downlink receiving boundary tracking adjustment module, an uplink transmitting boundary adjustment module and a timing advance command processing module; a downlink receiving boundary tracking adjusting module is configured to track a downlink receiving boundary, and accumulate each downlink receiving The adjustment amount of the boundary adjustment is obtained, and the cumulative adjustment amount is obtained, and the accumulated adjustment amount is transmitted to the uplink transmission boundary adjustment module; the uplink transmission boundary adjustment module is configured to perform corresponding uplink transmission according to the current cumulative adjustment amount obtained by tracking the downlink reception boundary. Boundary adjustment; the time advance command processing module is configured to dynamically monitor whether a time advance command arrives, and if so, prioritize the uplink transmit boundary adjustment according to the time advance command, and clear the accumulated adjustment amount.

The downlink receiving boundary tracking adjustment module performs only when the downlink adjustment period point arrives. The adjustment of the downlink reception boundary, the uplink transmission boundary adjustment module also performs the corresponding uplink transmission boundary adjustment according to the accumulated adjustment amount when the uplink adjustment period point arrives, and monitors whether there is a time advance quantity command to arrive to determine whether there is a downlink adjustment period. The cycle point or the cycle point of the uplink adjustment cycle arrives before or at the same time; of course, according to the actual needs of the system, it is also possible to perform real-time detection on whether there is a time advance command arrival, that is, to monitor it at any time, Meet the needs of the system.

 In the embodiment of the device, the uplink adjustment period may be selected according to the table or the actual requirement in the above method, and the corresponding maximum step size of the adjustment may also be selected according to the above proportional relationship.

 The apparatus of the present invention is illustrated below from a specific example:

Please refer to FIG. 2, which is an overall block diagram of an embodiment of the present invention. In the present embodiment, the corresponding physical quantities are the physical quantities in the above-mentioned methods cited. Initially, the cumulative adjustment amount Adjust_accumulated is set to 0; since the priority of the timing advance command is the highest, when each subframe arrives, the timing advance command processing module can first determine whether there is a TA command to be processed, if any Then, according to the TA command, the TX transmission boundary adjustment directly adjusts TX_offset (accumulated by TX_cmd) to the eNB's desired uplink and downlink reception boundary offset value (TX_target), and clears Adjust-accumulated to Adjust-accumulated= If there is no TA command to be processed, the downlink receiving boundary tracking adjustment module determines whether the periodic point of the RX_tracking_Period arrives. If yes, the downlink receiving boundary tracking adjustment module determines that the RX receiving boundary adjustment is performed according to the Adjust_value, that is, the RX_offset is updated to RX_offset+ Adjust_value , and Adj ust_accumulated= Ad just_accumulated+ Adjust—value , in order to ensure that each adjustment of RX_offset does not immediately affect the adjustment of the TX boundary, TX_offset needs to be updated accordingly, ie TX_offset=TX_offset+ Adjust_value; if RX_tracki If the periodic point of ng_period does not arrive, the downlink receiving boundary tracking adjustment module does not perform RX receiving boundary adjustment, and the uplink transmitting boundary adjustment module determines whether the periodic point of TX_tracking_period arrives, and if it arrives, then The row emission boundary adjustment module adjusts the TX emission boundary according to the value of Adjust_accumulated, as follows: If Adjust-accumulated Tq, directly adjust TX_target to TX_target+ Adjust-accumulated', if Adjust-accumulated >Tq', adjust TX_target to TX_target +Tq,, correspondingly, Adjust-accumulated is updated to Adjust-accumulated - Tq', and the updated Adjust-accumulated repeats the above steps when the cycle point of the next TX_tracking_period arrives. When the cycle point of TX_tracking_period does not arrive, the uplink emission boundary The adjustment module TX does not make adjustments.

 For a better understanding of the invention, a more specific example is given below for further explanation:

Initially, the accumulated adjustment amount Adjust_accumulated is set to 0, and the TX transmission boundary has adjusted the TX offset boundary and the actual offset TX_offset value of the RX reception boundary to the expected value of the eNB TX_target=l seconds according to the TA command; During a certain period of time, during the arrival of multiple RX_tracking_period periodic points, no TA command needs to be executed, and no cycle point of TX_tracking_period arrives. The RX receiving boundary is in the process of automatic tracking adjustment at the above multiple RX_tracking _period cycle points. The value of accumulated is updated to 0.5 seconds, that is, the RX receiving boundary is shifted in a certain direction by 0.5 seconds during this period. Referring to Figure 1, RX can be shifted to the right by 0.5 second; at this time, TX_offset=1.5; The offset value of the TX transmission boundary and the RX reception boundary is the value expected by the eNB, and the transmission boundary must also be shifted to the right by 0.5 seconds. The maximum adjustment step length Tq' corresponding to the TX_tracking_period is 0.25 seconds. If the TA command needs to be executed before the arrival of the cycle point of TX_tracking_period, and the TA command expects the expected offset of the TX transmission boundary and the RX reception boundary TX If _target is 2 seconds, that is, TX_cmd=0.5 sent by the TA command at this time, the TX transmission boundary should be offset by 0.5 seconds in the opposite direction of the RX reception boundary adjustment according to the TA command, so that TX_target=2 seconds, and Adjust-accumulated is cleared. If the cycle point of TX_tracking_period arrives without a TA command to be executed and no cycle point of RX_tracking_period arrives, the TX emission boundary is based on The ratio of Adjust_accumulated to Tq' is judged. At this time, the value of Adjust-accumulated is 0.5, which is greater than 0.25, so the direction of the TX emission boundary shifting to the RX receiving boundary is shifted by 0.25. At this time, TX_offset=1.25; Adjust_accumulated=0.5-0.25 When the cycle point of the next TX_tracking_period arrives, if there is a TA command to execute, and the TA command expects the expected offset TX_target of the TX transmission boundary and the RX reception boundary to be 2 seconds, that is, the TX_cmd=0.75 sent by the TA command, the TX transmission The boundary is offset by 0.75 seconds from the TA command to the opposite direction of the RX receive boundary adjustment (left in Figure 1) so that TX_target = 2 seconds, and Adjust-accumulated is cleared; if after adjusting the above TX transmit boundary until When the next TX_tracking_period point arrives, if there is no TA command to be executed and the value of Adjust-accumulated is still 0.25 seconds, then adjust TX_target to 1 according to the above TX transmission boundary adjustment, that is, keep the TA as expected by the base station. After the value is adjusted, Adj ust_accumulated to zero.

 In the present invention, the tracking adjustment is performed on the downlink receiving boundary, and each adjustment of Adjust_va lue is performed to obtain Adjust_accumulated. When the uplink adjustment period is reached, the uplink transmission boundary adjustment is performed according to the current Adjust-accumulated; During the above steps, when each subframe arrives, before detecting whether there is a periodic point of the uplink adjustment period or a period point of the downlink adjustment period, or at the same time, it is detected whether there is a TA command to be executed, and if so, the priority is based on the TA. The TX_cmd of the command adjusts the uplink transmission boundary and clears Adjust-accumulated to ensure that the time advance value of the uplink transmission boundary relative to the downlink reception boundary is the value expected by the base station, so as to better ensure the smooth reception of the base station.

In the present invention, the downlink adjustment period can be selected according to the needs of the specific situation, and the uplink adjustment period of the present invention can also be adjusted according to actual needs. For example, when the uplink transmission boundary frequently hops, a smaller uplink can be selected. Adjust the period to quickly track the transition of the uplink transmission boundary. When the row emission boundary is infrequently hopping, a larger uplink adjustment period can be selected, thereby reducing system overhead and saving energy. Therefore, this embodiment can satisfy different channel environments. Different performance requirements.

 In addition, the present invention sets the priority of the timing advance command to the highest priority, thereby processing the timing advance command and the uplink transmission boundary of the uplink transmission boundary according to the accumulated adjustment amount obtained by tracking the downlink reception boundary. Automatically adjust the organic combination to better ensure the reception of the base station.

 The above is a further detailed description of the present invention in connection with the specific embodiments, and the specific embodiments of the present invention are not limited to the description. It is to be understood by those skilled in the art that the present invention may be practiced without departing from the spirit and scope of the invention.

Claims

Claim  An uplink transmission timing control method in an LTE system, characterized in that: a cumulative adjustment amount is set; the method further includes:  Tracking the downlink receiving boundary, updating the accumulated adjustment amount according to the adjustment amount adjusted for each downlink receiving boundary, and performing uplink transmission boundary adjustment according to the current accumulated adjustment amount when the uplink transmission boundary is adjusted;  The dynamic monitoring of whether there is a time advance command sent by the base station needs to be performed, and then the uplink transmission boundary adjustment is performed according to the time advance command, and the accumulated adjustment amount is cleared.  The method according to claim 1, wherein the performing the uplink transmission boundary adjustment according to the current accumulated adjustment amount is: performing an uplink transmission boundary adjustment at a preset period of the uplink adjustment period, The uplink adjustment period includes at least one level.  The method according to claim 1, wherein the downlink receiving boundary is adjusted to: perform downlink receiving boundary adjustment at a periodic point of a preset downlink adjusting period;  The dynamically monitoring whether there is a time advance command sent by the base station needs to be performed as follows: determining whether the period of the uplink adjustment period and the period of the downlink adjustment period arrive before or at the same time.  4. The method according to claim 3, wherein when the uplink adjustment period includes multiple levels, different levels of uplink adjustment periods correspond to different maximum adjustment step sizes.  The method according to claim 4, wherein a ratio of a maximum adjustment step corresponding to an uplink adjustment period of each of the highest levels other than the highest level to a maximum adjustment step corresponding to the highest level of the uplink adjustment period, The ratio of the uplink adjustment period of each level other than the highest level to the highest level of the uplink adjustment period is the same. The method according to claim 5, wherein when the uplink adjustment period is the highest level of the uplink adjustment period, the corresponding maximum adjustment step size is an absolute adjustment step; and the value of the uplink adjustment period is For the highest level of the upstream adjustment period of 1/2, 1/4, and 1/8, The corresponding maximum adjustment step size is 1/2, 1/4, and 1/8 of the absolute adjustment step.  7. The method according to claim 6, wherein the method further comprises: selecting the uplink adjustment period corresponding thereto according to an adjustment frequency of the uplink transmission boundary of the different channel.  The method according to claim 7, wherein the performing the uplink transmission boundary adjustment according to the current accumulated adjustment amount is: determining whether the accumulated adjustment amount is greater than a maximum adjustment step corresponding to the uplink adjustment period Long, if not, the adjustment amount of the uplink emission boundary adjustment is directly the cumulative adjustment amount, and the accumulated adjustment amount is cleared; if yes, the adjustment amount of the uplink emission boundary adjustment is the maximum adjustment step size, The cumulative adjustment amount correspondingly decreases the maximum adjustment step size, and when the period point of the next uplink adjustment period comes, the step of determining the cumulative adjustment amount is repeated.  An uplink transmission timing control apparatus in an LTE system, wherein the apparatus includes a downlink reception boundary tracking adjustment module, an uplink transmission boundary adjustment module, and a timing advance command processing module;  The downlink receiving boundary tracking adjustment module is configured to track a downlink receiving boundary, update a preset cumulative adjustment amount according to an adjustment amount adjusted for each downlink receiving boundary, and transmit the accumulated adjustment amount to the uplink transmission Boundary adjustment module;  The uplink transmission boundary adjustment module is configured to perform corresponding uplink transmission boundary adjustment according to the current cumulative adjustment amount obtained by tracking the downlink receiving boundary.  The time advance command processing module is configured to dynamically monitor whether a time advance command is required to be executed, and then perform uplink transmit boundary adjustment according to the time advance command, and clear the accumulated adjustment amount. The apparatus according to claim 9, wherein the uplink transmission boundary adjustment module performs uplink transmission boundary adjustment according to the cumulative adjustment amount, which is performed at a periodic point of a preset uplink adjustment period, where The uplink adjustment period includes at least one level. The apparatus according to claim 9, wherein the downlink receiving boundary adjustment performed by the downlink receiving boundary tracking adjustment module is performed at a periodic point of a preset downlink adjustment period;  The time advance command processing module is further configured to dynamically monitor whether a time advance command sent by the base station needs to be executed before determining whether there is a periodic point of the uplink adjustment period and a period point of the downlink adjustment period is reached or At the same time.  12. The apparatus according to claim 11, wherein when the uplink adjustment period includes multiple levels, different levels of uplink adjustment periods correspond to different maximum adjustment step sizes.  The apparatus according to claim 12, wherein a ratio of a maximum adjustment step corresponding to an uplink adjustment period of each of the highest levels other than the highest level to a maximum adjustment step corresponding to the highest level of the uplink adjustment period, The ratio of the uplink adjustment period of each level other than the highest level to the highest level of the uplink adjustment period is the same.  The device of claim 13, wherein the uplink transmission boundary adjustment module determines whether the cumulative adjustment amount is greater than the corresponding uplink adjustment period when the uplink transmission boundary adjustment is performed according to the cumulative adjustment amount. The maximum adjustment step size, if not, the adjustment amount of the uplink emission boundary adjustment is directly the cumulative adjustment amount, and the accumulated adjustment amount is cleared; if yes, the adjustment amount of the uplink emission boundary adjustment is The maximum adjustment step size is reduced, and the cumulative adjustment amount is correspondingly reduced by the maximum adjustment step size, and when the cycle point of the next uplink adjustment period comes, the operation of determining the accumulated adjustment amount is repeated.