CN102244536A - Method and apparatus for uplink synchronization in mobile communication system - Google Patents

Abstract

The invention provides a method and device for uplink synchronization in a mobile communication system, relates to the field of communication, and solves the problem of uplink out-of-synchronization in the prior art when UE has no business transmission for a long time. The method includes: obtaining a receiving sequence of multiple subframes in a local receiving frame and a locally preset local sequence; obtaining the downlink timing of the receiving frame according to the phase information of the multiple receiving sequences and the local sequence Offset information; Uplink synchronization is performed by using the downlink time offset information of the received frame; wherein the received frame is a frame sent by the base station and received locally after being transmitted through a wireless channel. The technical solution provided by the invention can be applied to the field of mobile communication.

Description

Method and device for uplink synchronization in mobile communication system

technical field

The present invention relates to the communication field, in particular to a method and device for uplink synchronization in a mobile communication system.

Background technique

In the LTE (Long Term Envolution, long-term evolution) system, the synchronization between the base station and the UE (user terminal) is a very critical issue, which includes downlink synchronization and uplink synchronization. Primary and secondary synchronization information, obtain the wireless frame header and perform fine synchronization on this basis. Fine synchronization ensures real-time synchronization between the UE and the base station. The uplink synchronization means that the data received by the base station from each UE must be aligned with the wireless frame frequency. Generally, the initial synchronization is obtained through a random access process. The synchronization after access can use the base station to detect uplink data or control signals to obtain The TA (Time Advanced, time advance) value is sent to the UE, and the UE adjusts the data transmission time according to the TA value to achieve uplink synchronization.

With reference to accompanying drawing 1, this figure shows the LTE system synchronization process in the prior art, including steps:

Step S101: NodeB broadcasts a system broadcast message on a broadcast channel;

The system broadcast message contains various parameter configurations of the current cell, specifically bandwidth information, duplex mode, cell type, subframe configuration, random access format time slot configuration, frequency domain resource RB (Resource Blocks, resource block) Occupancy, NCS (Number of cyclic shifts index, cyclic shift numerical index) configuration, root sequence logic index, cyclic shift selection, etc.;

Step S102: UE performs downlink synchronization, searches broadcast channels, and obtains system broadcast messages;

Step S103: UE downlink performs fine synchronization during normal service processing to ensure real-time downlink synchronization;

Step S201: UE generates a preamble sequence according to various parameter configurations of the current cell contained in the system broadcast message;

The leading sequence is shown in Figure 2, including CP (Cyclic Prefix, cyclic prefix) and detection data sequence Sequence. Wherein, the correlation peak information of the leading sequence will be at the starting position of the selected root sequence cyclic shift region;

Step S202: UE sends the generated preamble sequence to NodeB through the antenna interface;

Step S203: NodeB receives the preamble sequence sent by the UE, periodically intercepts the preamble sequence data, and then detects the intercepted data to obtain the air interface transmission delay TA1 value;

The protocol does not distinguish between the TA1 measured by RACH (Random Access Channel) during the access process and the TA2 obtained by the service measurement after access, both of which are recorded as TA. In this method description, they are recorded separately according to the generation time Do TA1 and TA2 for easy description. TA1 refers to the air interface transmission delay between the UE and the base station, which directly reflects the position of the antenna port between the UE and the NodeB, and this value is the air interface-round-trip delay. The range of random access TA1 in the protocol is 0 to 1282. When TA1=0, it means that there is no transmission delay to be overcome between UE and NodeB, and the timings of the two are aligned.

Step S204: NodeB sends TA1 to UE, UE judges whether TA is 0 after obtaining this value, if not 0, enters S205; if it is 0, directly enters S206;

Step S205: UE advances its timing by TA1;

Step S206: UE completes the whole access process, and then sends service data;

Step S207: NodeB receives the service data and measures the TA2 value;

TA2 refers to the time offset value caused by the frequency offset between the UE and NodeB due to the clock local oscillator or the UE is moving. The protocol stipulates that this value ranges from 0 to 63. When TA2=32, it means that the UE and NodeB It is aligned and no timing adjustment is required. When TA2>32, it indicates that the UE transmits late and needs to be adjusted forward, and vice versa.

Step S208: NodeB sends TA2 to the UE, and the UE judges whether the TA value is greater than 32, and if so, enters S210; otherwise, enters 209;

Step S209: Determine whether TA2 is less than 32, if less, go to S211, otherwise go to S206;

Step S210: UE adjusts its timing forward by TA2-32, and enters S206;

Step S211: UE adjusts its timing backward by 32-TA2, and enters S206.

In the process of realizing the above, the inventor found that if there is no uplink service uploaded to the NodeB for a long time, the NodeB cannot obtain TA2 according to the service data, and the UE cannot make TA2 adjust its own timing, which may cause uplink loss of synchronization.

Contents of the invention

The present invention provides a method and device for uplink synchronization in a mobile communication system, which solves the problem in the prior art that the uplink is out of synchronization when the UE has no business transmission for a long time.

In order to solve the problems of the technologies described above, the present invention provides the following technical solutions:

A method for uplink synchronization in a mobile communication system, comprising:

Obtain the reception sequence of multiple subframes in the local reception frame and the local preset local sequence;

Acquiring downlink time offset information of the received frame according to the phase information of the plurality of received sequences and the local sequence;

performing uplink synchronization by using the downlink time offset information of the received frame;

The received frame is a frame sent by the base station and received locally after being transmitted through a wireless channel.

Further, the downlink time offset information of the received frame is obtained in the following manner:

Obtaining the phase difference between each received sequence and the same adjacent point in the local sequence;

Obtaining downlink time offset information of each subframe in the received frame according to the phase difference between the adjacent points;

Acquire the downlink time offset information of the received frame according to the downlink time offset information of each subframe in the received frame.

Further, the downlink time offset information of each subframe in the received frame is

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; \&angle;</span><span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; ,</span>$

Where r(k) represents the received sequence of the subframe in the received frame, s(k) represents the local local sequence, * represents the conjugation, ∠ represents the operation of taking the phase angle, and M represents the received sequence or the local sequence The number of midpoints, where k=0, . . . , M-1.

Further, the uplink synchronization includes adjusting the uplink timing and length of the transmission frame that needs to be sent locally to the base station,

Wherein, adjusting the uplink timing of the sending frame includes: if the downlink timing offset information of the receiving frame is equal to 0, then not adjusting the uplink timing of the sending frame; if it is greater than 0, then adjusting backward the timing of the sending frame Uplink timing; if it is less than 0, then adjust the uplink timing of the sending frame forward, wherein the adjustment position of the uplink timing is the starting position of the next frame frequency of the current uplink timing, and the change size of the uplink timing is the specified The absolute value of the downlink time offset information of the received frame;

Wherein adjusting the length of the sending frame includes: if the downlink time offset information of the receiving frame is equal to 0, then not adjusting the length of the sending frame; if greater than 0, increasing the length of the sending frame; if less than 0, Then reduce the length of the sending frame; wherein the adjustment range of the frame length is the cyclic prefix (CP) of one symbol in the sending frame, and the change size of the frame length is the downlink time offset information of the receiving frame the absolute value of .

A device for uplink synchronization in a mobile communication system, comprising:

The first obtaining module is used to obtain the receiving sequence of multiple subframes in the local receiving frame and the locally preset local sequence;

A second acquisition module, connected to the first acquisition module, configured to acquire the downlink time offset information of the received frame according to the phase information of the plurality of received sequences and the local sequence;

A synchronization module, connected to the second acquisition module, configured to use the downlink time offset information of the received frame to perform uplink synchronization;

The received frame is a frame sent by the base station and received locally after being transmitted through a wireless channel.

Further, the second acquisition module includes:

a first acquiring unit, configured to acquire a phase difference between each received sequence and the same adjacent point in the local sequence;

A second acquisition unit, connected to the first acquisition unit, configured to obtain downlink time offset information of each subframe in the received frame according to the phase difference between the adjacent points;

A third obtaining unit, connected to the second obtaining unit, configured to obtain the downlink time offset information of the received frame according to the downlink time offset information of each subframe in the received frame.

Further, the downlink time offset information of each subframe in the received frame is

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; \&angle;</span><span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; ,</span>$

Where r(k) represents the receiving sequence of the subframe in the receiving frame, s(k) represents the local local sequence; * represents conjugation, ∠ represents the operation of taking the phase angle, and M represents the receiving sequence or the local sequence The number of midpoints, where k=0, . . . , M-1.

Further, the synchronization module includes:

The first adjustment unit is configured to adjust the uplink timing of the sending frame that needs to be sent locally to the base station. If the downlink timing offset information of the receiving frame is equal to 0, the uplink timing of the sending frame is not adjusted; if it is greater than 0, adjust the uplink timing of the sending frame backward; if it is less than 0, adjust the uplink timing of the sending frame forward, wherein the adjustment position of the uplink timing is the start of the next frame frequency of the current uplink timing position, the variation of the uplink timing is the absolute value of the downlink time offset information of the received frame;

The second adjustment unit, used to adjust the length of the sending frame that needs to be sent locally to the base station includes: if the downlink time offset information of the receiving frame is equal to 0, then not adjusting the length of the sending frame; if it is greater than 0, then Increase the length of the sending frame; if it is less than 0, then reduce the length of the sending frame; wherein the adjustment range of the frame length is the cyclic prefix (CP) of a symbol in the frame that the local needs to send to the base station ), the variation of the frame length is the absolute value of the downlink time offset information of the received frame.

One or more embodiments provided by the present invention use the downlink time offset determined by the phase difference between the received sequence and the local sequence to perform uplink synchronization, and can perform uplink synchronization in real time, which is similar to that in the prior art that can only perform uplink synchronization when there is service data. Compared with that, there will be no uplink out-of-sync problem, which improves the reliability of the network.

Description of drawings

FIG. 1 is a schematic flow diagram of a method for uplink synchronization in a mobile communication system in the prior art;

FIG. 2 is a schematic diagram of a preamble data format in the prior art;

FIG. 3 is a schematic flowchart of an embodiment of a method for uplink synchronization in a mobile communication system provided by the present invention;

FIG. 4 is a schematic flowchart of an application example of a method for uplink synchronization in a mobile communication system provided by the present invention;

FIG. 5 is a schematic diagram 1 of timing and data before and after timing adjustment in the present invention;

FIG. 6 is a schematic diagram 2 of timing and data before and after timing adjustment in the present invention;

FIG. 7 is a schematic structural diagram of an embodiment of a device for uplink synchronization in a mobile communication system provided by the present invention;

FIG. 8 is a schematic structural diagram of a second acquisition module 702 in the embodiment shown in FIG. 7;

FIG. 9 is a schematic structural diagram of the synchronization module 703 in the embodiment shown in FIG. 7 .

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 3 is a schematic flowchart of an embodiment of a method for uplink synchronization in a mobile communication system provided by the present invention. The method embodiment shown in Figure 3 includes:

Step S301: Obtain the receiving sequence of multiple subframes in the local receiving frame and the locally preset local sequence;

Step S302: Obtain downlink time offset information of the received frame according to the phase information of the plurality of received sequences and the local sequence;

Step S303: Perform uplink synchronization by using the downlink time offset information of the received frame;

The received frame is a frame sent by the base station and received locally after being transmitted through a wireless channel.

The method provided by the embodiment of the present invention uses the downlink time offset determined by the phase difference between the received sequence and the local sequence to perform uplink synchronization, and can perform uplink synchronization in real time. Compared with the prior art, uplink synchronization can only be performed when there is service data. There will be a problem of uplink out-of-sync, which improves the reliability of the network.

The method provided by the present invention is further described below:

Fig. 4 is a schematic flowchart of an application example of the uplink synchronization method in the mobile communication system provided by the present invention. The application example shown in Figure 4 includes:

Step S401: The UE detects that the local area and the base station have not achieved accurate uplink synchronization;

Among them, the coarse adjustment method for uplink synchronization in the prior art is applicable to the present invention, for example, it can be realized in the following way:

The UE obtains downlink synchronization, and obtains the parameter configuration of the current cell contained in the system broadcast message; generates a preamble sequence according to the cell-related parameters obtained in the downlink, and sends it to the NodeB to obtain the air interface delay TA1 detected by the NodeB; The air interface delay TA1 value overcomes the transmission delay between UE and NodeB.

Step S402: The UE obtains the received sequence of multiple subframes and the local local sequence in the received frame sent by the NodeB.

The NodeB will actively send a frame including pilot signal information to the UE. After the wireless channel transmission, the UE receives the frame and reads all or part of the subframe sequence from the frame including the pilot signal information as the received frame. sequence;

The local sequence is generated by the UE according to the protocol. For a specific UE, the local sequence is unique, that is, all received sequences are correlated with this local sequence.

Step S403, the UE acquires the phase difference between each received sequence and the same adjacent point in the local sequence;

In this step, it is assumed that r(k), k=0,..., M-1 is the received sequence, s(k), k=0,..., M-1 is the local sequence, where k represents the received sequence or local sequence.

k＝0，...，M-1，其中N表示FFTSIZE(fastFouriertransform SIZE，快速傅立叶变化的大小)；When the current bias is m points, without considering the influence of channel and noise, the relationship between received data and sent data is

k=0,..., M-1, wherein N represents FFTSIZE (fastFouriertransform SIZE, the size of fast Fourier transform);

The phase difference between adjacent points is obtained as follows:

${\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}$

$<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; j</span>}\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\mathrm{<span\; class="notranslate">\; km</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}$

$<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; m</span>}}{<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}$

$<span\; class="notranslate">\; =</span>{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; |</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; e</span>}}^{\mathrm{<span\; class="notranslate">\; j</span>}\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; N</span>}}\mathrm{<span\; class="notranslate">\; m</span>}}$

Step 404: The UE obtains the downlink time offset information of each subframe in the received frame according to the phase difference between each adjacent point.

In this step, the downlink time offset information of each subframe is calculated using the following formula

$\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; \&angle;</span><span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; \}</span>$

in Represents the downlink time offset estimated value of each subframe, r(k) represents the sequence of subframes in the received frame, s(k) represents the local sequence corresponding to the local and received sequence, ^ represents the operation of obtaining the estimated value, * represents the conjugate, ∠ represents the operation of taking the phase angle, M is the number of midpoints in the receiving sequence or the local sequence, where k=0,...,M-1.

Step S405: The UE obtains the downlink time offset information of the received frame according to the downlink time offset information of each subframe in the received frame.

In this step, the downlink time offset information of each subframe is averaged to obtain the downlink time offset information of the received frame.

Step S406, the UE uses the downlink time offset information of the received frame to perform uplink synchronization.

In this step, the uplink synchronization includes adjusting the uplink timing and length of the transmission frame that needs to be sent locally to the base station,

The adjustment of the uplink timing of the sending frame includes: if the downlink timing offset information of the receiving frame is equal to 0, then the uplink timing of the sending frame is not adjusted; if it is greater than 0, then the uplink timing of the sending frame is adjusted backward; if it is less than 0, then Adjusting the uplink timing of the sending frame forward, wherein the adjusted position of the uplink timing is the starting position of the next frame rate of the current uplink timing, and the change of the uplink timing is the absolute value of the downlink time offset information of the received frame;

Wherein adjusting the length of the sending frame includes: if the downlink time offset information of the receiving frame is equal to 0, then do not adjust the length of the sending frame; if it is greater than 0, then increase the length of the sending frame; if it is less than 0, then reduce the length of the sending frame; The adjustment range of the frame length is the cyclic prefix (CP) of one symbol in the sending frame, and the variation of the frame length is the absolute value of the downlink time offset information of the receiving frame.

Specifically, one subframe includes 14 symbols, and one symbol includes L pieces of IQ (Inphase Quadrature) data, and L varies with different application bandwidths. In actual application, the first symbol, the second symbol or other symbols can be selected for adjustment; when the number of IQ data in the CP is adjusted, the added or deleted IQs are continuous.

5 and 6 are schematic diagrams of timing and data before and after timing adjustment in the present invention, wherein the schematic diagram shown in FIG. 5 is a schematic diagram when the downlink time offset information is less than 0; the schematic diagram shown in FIG. Schematic diagram for case 0.

In practical applications, since the frequency offset always exists between UE and NodeB, after a period of time, when the time offset value obtained in step S405 is greater than the minimum granularity that can be detected locally, uplink synchronization needs to be performed.

It should be noted that in this application example, since the UE performs uplink synchronization using the downlink time offset determined by the phase difference between the received sequence and the local sequence, the uplink synchronization can be performed in real time, which is different from the prior art in which uplink synchronization can only be performed when there is service data. In contrast, there will be no situation where uplink synchronization is not performed for a long time, thereby avoiding the occurrence of uplink out-of-sync phenomenon.

Here are two specific application examples:

Specific application example one:

Assuming that in a NodeB and UE system, the frequency of the local oscillator of the UE is faster than that of the NodeB, the implementation steps of using this patent are as follows:

Step 1: The UE obtains downlink synchronization, and obtains the parameter configuration of the current cell contained in the system broadcast message;

Step 2: The UE uplink generates a preamble sequence based on the cell-related parameters solved in the downlink, and sends it to the NodeB. The NodeB detects the air interface delay TA1, and sends it to the UE;

Step 3: On the basis of downlink synchronization, the UE advances the uplink timing by the value of TA1 to obtain the uplink timing;

Step 4: The UE demodulates the pilot signal received in the downlink, and then performs a correlation operation according to a certain algorithm to obtain the estimated value of the downlink time offset. Here, it is assumed that the estimated value of the calculated time offset is 6TS;

Step 5: The UE judges whether the estimated time offset value is greater than 0. At this time, 6TS is greater than 0. Then, on the basis of the current uplink timing, at the starting position of the next frame frequency, the uplink timing is delayed by 6TS, so that the uplink timing and NodeB are reached. micro-synchronization;

Step 6: Another operation that is synchronized with step 5 is that the UE needs to adjust the data. The starting position of the next frame after obtaining the estimated time offset value of 6TS in the uplink is the first symbol of the CP in the current frame. Add 6 IQ data before the IQ data. From the perspective of the UE, the CP value length of the first symbol of the adjusted frame is increased by 6TS, that is, the CP length is changed from 160TS to 166TS. At this point, an uplink micro-synchronization ends;

Specific application example two

Assume that in a NodeB and UE system, the local oscillator frequency of the UE is slower than that of the NodeB;

Step 1: The UE obtains downlink synchronization, and obtains the parameter configuration of the current cell contained in the system broadcast message;

Step 2: The UE uplink generates a preamble sequence based on the cell-related parameters solved in the downlink, and sends it to the NodeB. The NodeB detects the air interface delay TA1, and sends it to the UE;

Step 3: On the basis of downlink synchronization, the UE advances the uplink timing by the value of TA1 to obtain the uplink timing;

Step 4: The UE demodulates the pilot signal received in the downlink, and obtains the estimated value of the downlink time offset. Here, it is assumed that the estimated value of the calculated time offset is -6TS;

Step 5: The UE judges whether the estimated time offset value is greater than 0. At this time, -6TS is less than 0. Then, on the basis of the current uplink timing, at the starting position of the next frame frequency, the uplink timing is advanced by 6TS, so that the uplink timing and the NodeB are Micro-synchronization is achieved;

Step 7: The UE adjusts the data, and sends the first symbol CP of the current frame from the seventh IQ data at the starting position of the next frame after obtaining the estimated time offset value of -6TS in the uplink, that is, does not send the first symbol CP For the first 6 IQ data of a symbol CP, from the perspective of UE, the length of the first symbol CP of this adjustment frame changes from 160TS to 154TS, and of course the length of this adjustment frame changes from 307200 to 307194. So far, an uplink micro-synchronization ends.

Fig. 7 is a schematic structural diagram of an embodiment of an apparatus for uplink synchronization in a mobile communication system provided by the present invention. Combining the contents shown in Figures 3 to 6, the device shown in Figure 7 includes:

The first acquiring module 701 is configured to acquire the receiving sequence of multiple subframes in the local receiving frame and the locally preset local sequence;

A second acquisition module 702, connected to the first acquisition module 701, configured to acquire downlink time offset information of the received frame according to the phase information of the multiple received sequences and the local sequence;

The synchronization module 703 is connected to the second acquisition module 702 and configured to perform uplink synchronization by using the downlink time offset information of the received frame.

FIG. 8 is a schematic structural diagram of the second acquiring module 702 in the embodiment shown in FIG. 7 . The second acquiring module 702 shown in FIG. 9 includes:

The first acquiring unit 801 is configured to acquire the phase difference between each received sequence and the same adjacent point in the local sequence;

The second obtaining unit 802 is connected to the first obtaining unit 801, and is configured to obtain the downlink time offset information of each subframe in the receiving frame according to the phase difference between the adjacent points;

A third obtaining unit, connected to the second obtaining unit, configured to obtain the downlink time offset information of the received frame according to the downlink time offset information of each subframe in the received frame.

A third obtaining unit 803, connected to the second obtaining unit 802, configured to obtain the downlink time offset information of each subframe in the received frame according to the phase difference between the adjacent points;

Wherein the downlink time offset information of each subframe in the received frame is

$\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; m</span>}}\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}\frac{\mathrm{<span\; class="notranslate">\; N</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}}<span\; class="notranslate">\; \&angle;</span><span\; class="notranslate">\; \{</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; r</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; \}</span><span\; class="notranslate">\; ,</span>$

Where r(k) represents the received sequence of the subframe in the received frame, s(k) represents the local local sequence, * represents the conjugation, ∠ represents the operation of taking the phase angle, and M represents the received sequence or the local sequence The number of midpoints, where k=0, . . . , M-1.

FIG. 9 is a schematic structural diagram of the synchronization module 703 in the embodiment shown in FIG. 7 . Synchronization module 803 shown in Figure 9 includes:

The first adjustment unit is configured to adjust the uplink timing of the sending frame that needs to be sent locally to the base station. If the downlink timing offset information of the receiving frame is equal to 0, the uplink timing of the sending frame is not adjusted; if it is greater than 0, adjust the uplink timing of the sending frame backward; if it is less than 0, adjust the uplink timing of the sending frame forward, wherein the adjustment position of the uplink timing is the start of the next frame frequency of the current uplink timing position, the variation of the uplink timing is the absolute value of the downlink time offset information of the received frame;

The second adjustment unit is used to adjust the length of the sending frame that needs to be sent locally to the base station. If the downlink time offset information of the receiving frame is equal to 0, the length of the sending frame will not be adjusted; if it is greater than 0, then increase The length of the sending frame; if less than 0, then reduce the length of the sending frame; wherein the adjustment range of the frame length is the cyclic prefix (CP) of a symbol in the sending frame, the change of the frame length The size is the absolute value of the downlink time offset information of the received frame.

The device provided by the present invention uses the downlink time offset determined by the phase difference between the receiving sequence and the local sequence to perform uplink synchronization, and can perform uplink synchronization in real time. The problem of uplink out-of-synchronization improves the reliability of the network.

Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned embodiments can be implemented using a computer program flow, the computer program can be stored in a computer-readable storage medium, and the computer program can be run on a corresponding hardware platform (such as system, device, device, device, etc.), and when executed, includes one or a combination of the steps of the method embodiment.

Optionally, all or part of the steps in the above embodiments can also be implemented using integrated circuits, and these steps can be fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module accomplish. As such, the present invention is not limited to any specific combination of hardware and software.

The devices/functional modules/functional units in the above embodiments can be realized by general-purpose computing devices, and they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices.

When each device/functional module/functional unit in the above-mentioned embodiments is realized in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer-readable storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope described in the claims.

Claims (8)

1. the method for a uplink synchronous in mobile communication system is characterized in that, comprising:

Obtain the receiving sequence and the local local sequence that sets in advance of a plurality of subframes in the local received frame;

According to the phase information of described a plurality of receiving sequences and described local sequence, breath believes one side only when obtaining described received frame descending;

The breath that believes one side only when adopting described received frame descending carries out uplink synchronous;

Wherein said received frame is that the base station sends and transmits the frame of back local reception through wireless channel.

2. method according to claim 1 is characterized in that, the breath that believes one side only during described received frame descending obtains in the following way:

Obtain the phase difference between identical consecutive points in described each receiving sequence and the described local sequence;

Breath believes one side only when obtaining each subframe in the described received frame descending according to the phase difference between described consecutive points;

The breath that believes one side only during according to each subframe in the described received frame descending, breath believes one side only when obtaining described received frame descending.

3. method according to claim 2 is characterized in that, the breath that believes one side only during each subframe descending in the described received frame is

The receiving sequence of subframe in the described received frame of r (k) expression wherein, the local local sequence of s (k) expression, * represents conjugation, and ∠ represents to get the computing of phase angle, and M represents the number of described receiving sequence or described local sequence mid point, k=0 wherein ..., M-1.

4. method according to claim 1 is characterized in that, described uplink synchronous comprises need carry out the adjustment of up sequential and length to the transmit frame that described base station sends to this locality,

The up sequential of wherein adjusting described transmit frame comprises: if the breath that believes one side only during described received frame descending equals 0, then the up sequential of described transmit frame is not adjusted; If greater than 0, then adjust the up sequential of described transmit frame backward; If less than 0, then adjust the up sequential of described transmit frame forward, the adjustment position of wherein said up sequential is the original position of the next frame frequency of current up sequential, believe one side only during for described received frame the descending absolute value of breath of the variation of described up sequential size;

The length of wherein adjusting described transmit frame comprises: if the breath that believes one side only during described received frame descending equals 0, then do not adjust the length of described transmit frame; If greater than 0, then increase the length of described transmit frame; If less than 0, then reduce the length of described transmit frame; The adjusting range of wherein said frame length is the Cyclic Prefix (CP) of a symbol in the described transmit frame, believe one side only during for described received frame the descending absolute value of breath of the variation of described frame length size.

5. the device of a uplink synchronous in mobile communication system is characterized in that, comprising:

First acquisition module is used for obtaining the receiving sequence of the local a plurality of subframes of received frame and the local sequence that this locality sets in advance;

Second acquisition module links to each other with described first acquisition module, is used for the phase information according to described a plurality of receiving sequences and described local sequence, and breath believes one side only when obtaining described received frame descending;

Synchronization module links to each other with described second acquisition module, and the breath that believes one side only when being used to adopt described received frame descending carries out uplink synchronous;

Wherein said received frame is that the base station sends and transmits the frame of back local reception through wireless channel.

6. device according to claim 5 is characterized in that, described second acquisition module comprises:

First acquiring unit is used for obtaining the phase difference between described each receiving sequence and the identical consecutive points of described local sequence;

Second acquisition unit links to each other with described first acquiring unit, and breath believes one side only when being used for obtaining each subframe in the described received frame descending according to the phase difference between described consecutive points;

The 3rd acquiring unit links to each other with described second acquisition unit, the breath that believes one side only when being used for according to each subframe in the described received frame descending, and breath believes one side only when obtaining described received frame descending.

7. device according to claim 6 is characterized in that, the breath that believes one side only during each subframe descending in the described received frame is

Wherein r (k) represents the receiving sequence of subframe in the described received frame, the local local sequence of s (k) expression; * represent conjugation, ∠ represents to get the computing of phase angle, and M represents the number of described receiving sequence or described local sequence mid point, k=0 wherein ..., M-1.

8. device according to claim 5 is characterized in that, described synchronization module comprises:

First adjustment unit is used to adjust the up sequential of the transmit frame that this locality need send to described base station, if the breath that believes one side only during described received frame descending equals 0, then the up sequential of described transmit frame is not adjusted; If greater than 0, then adjust the up sequential of described transmit frame backward; If less than 0, then adjust the up sequential of described transmit frame forward, the adjustment position of wherein said up sequential is the original position of the next frame frequency of current up sequential, believe one side only during for described received frame the descending absolute value of breath of the variation of described up sequential size;

Second adjustment unit is used to adjust the length of the transmit frame that this locality need send to described base station, if the breath that believes one side only during described received frame descending equals 0, does not then adjust the length of described transmit frame; If greater than 0, then increase the length of described transmit frame; If less than 0, then reduce the length of described transmit frame; The adjusting range of wherein said frame length is the Cyclic Prefix (CP) of a symbol in the described transmit frame, believe one side only during for described received frame the descending absolute value of breath of the variation of described frame length size.

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