WO2011020421A1

WO2011020421A1 - Method and device of preamble configuration

Info

Publication number: WO2011020421A1
Application number: PCT/CN2010/076041
Authority: WO
Inventors: 武春璟; 郑勐
Original assignee: 华为技术有限公司
Priority date: 2009-08-18
Filing date: 2010-08-17
Publication date: 2011-02-24
Also published as: CN101998637B; CN101998637A

Abstract

A method and a device of preamble configuration. The method includes acquiring the identification information of preambles corresponding to a cell. The preambles corresponding to the cell include contention preambles and non-contention preambles. The non-contention preambles include useful non-contention preambles and useless non-contention preambles. According to the identification information, the corresponding contention preambles and useful non-contention preambles are confirmed. The reference root sequence information for creating the contention preambles and the useful non-contention preambles are obtained. According to the reference root sequence information, reference root sequences are generated. The method and device can only obtain the reference root sequence information that generates the contention preambles and the useful non-contention preambles, and thereby generate the reference root sequences only related to the contention preambles and the useful non-contention preambles. The method and device avoid detecting the root sequences of all preambles supported by the cell after receiving a preamble signal. The method and device save resources, reduce detection time delay, and thereby reduce the terminal connecting time delay and switching time delay.

Description

The present invention claims priority to Chinese Patent Application No. 200910091348.5, entitled "Preamble Configuration Method and Apparatus", filed on August 18, 2009, the entire contents of which are hereby incorporated by reference. Combined in this application.

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method and apparatus for configuring a preamble. Background technique

In an Evolved Packet System (EPS) network, the initial non-synchronized random access procedure is part of a user equipment (UE) accessing a cell or performing cell handover. The asynchronous random access signal is usually carried in a random burst, and the content of the random burst is a Physical Random Access Channel preamble. The PRACH preamble is a signal in the time domain. Cyclic shifting of a root sequence can result in a cyclic shift sequence, and a PRACH preamble can be generated based on the cyclic shift sequence. The number of root sequences used by different cells may be different, and each cell needs to support 64 PRACH preambles. By performing correlation detection on the root sequence that generates the PRACH preamble, the uplink clock of the UE can be adjusted to implement uplink synchronization between the UE and the system.

In the existing non-synchronous random access process, when the base station receives a PRACH preamble and performs correlation detection on the root sequence, the detection delay is long, resulting in a longer access delay and a longer handover time of the UE. Summary of the invention

Embodiments of the present invention provide a method and apparatus for configuring a preamble.

In one aspect, an embodiment of the present invention provides a method for configuring a preamble, including:

Acquiring the identification information of the preamble corresponding to the cell, where the preamble corresponding to the cell includes a competitive preamble and a non-competitive preamble, and the non-competitive preamble includes a useful non-competitive predecessor and a useless non-competitive preamble; Determining a corresponding competitive preamble and a useful non-competitive preamble according to the identification information; acquiring reference root sequence information that generates the competitive preamble and the useful non-competitive preamble; and generating a reference root sequence according to the reference root sequence information .

On the other hand, the embodiment of the present invention further provides a preamble configuration apparatus, including: an identifier module, configured to acquire identifier information of a preamble corresponding to a cell, where a preamble corresponding to the cell includes a preamble and a non-contention preamble. The non-competitive predecessor includes useful non-competitive predecessors and useless non-competitive predecessors;

a determining module, configured to determine, according to the identification information acquired by the identifier module, a corresponding competitive preamble and a useful non-competitive preamble;

An obtaining module, configured to obtain reference root sequence information that generates a competitive preamble and a useful non-competitive preamble determined by the determining module;

And a processing module, configured to generate a reference root sequence according to the reference root sequence information acquired by the acquiring module.

In another aspect, an embodiment of the present invention further provides a base station, including the foregoing preamble configuration apparatus. According to the foregoing technical solution, in the embodiment of the present invention, the physical layer of the base station, for example, the base station, may be determined according to the identifier information of the preamble corresponding to the cell, by setting the preamble corresponding to the cell as the contention preamble, the useful non-contention preamble, and the useless non-contention preamble. The competitive preamble and the useful non-competitive predecessor obtain only the reference root sequence information used to generate the competitive preamble and the useful non-competitive preamble, and no longer obtain the reference root sequence information used to generate the useless non-competitive preamble, thereby generating It is only the reference root sequence associated with the competitive leader and the useful non-competitive leader. The embodiment of the invention avoids detecting the reference root sequence corresponding to all the preambles supported by the cell when receiving a preamble signal, saves resources, reduces detection delay, and reduces access delay of the terminal. Switch delay. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in FIG. Other drawings can also be obtained from these drawings on the premise of sex.

1 is a schematic flowchart of a method for configuring a preamble according to Embodiment 1 of the present invention; 2 is a schematic flowchart of a configuration method of a preamble according to Embodiment 2 of the present invention; and FIG. 3 is a schematic structural diagram of a preamble configuration apparatus according to Embodiment 3 of the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

FIG. 1 is a schematic flowchart of a method for configuring a preamble according to Embodiment 1 of the present invention. As shown in FIG. 1 , a method for configuring a preamble in this embodiment may include the following steps:

Step 101: Obtain identification information of a preamble corresponding to the cell, where the preamble corresponding to the cell includes a competitive preamble and a non-competitive preamble, and the non-competitive preamble includes a useful non-competitive preamble and a useless non-competitive preamble; Step 102, according to the foregoing identifier The information determines the competition leading and the useful non-competitive predecessor corresponding to the cell;

Step 103: Acquire reference root sequence information for generating a competition preamble and a useful non-contention preamble; Step 104: Generate a reference root sequence according to the reference root sequence information of the foregoing competition preamble and the useful non-contention preamble.

In this embodiment, since the non-contention access preamble is mainly used for cell handover of the UE, and which preamble used by the UE can be specified by the base station. Therefore, all PRACH preambles corresponding to the cell can be set to three categories: competitive preamble, useful non-competitive predecessor, useless non-competitive predecessor. The base station only needs to select from the useful non-competition predecessor when assigning the non-competitive preamble to the to-be-switched terminal.

In this embodiment, the preamble corresponding to the cell is set as a preamble, a useful non-competitive preamble, and a useless non-competitive preamble through the protocol upper layer (layer 2 or layer 3) of the base station, and the identifier information of the foregoing various preambles is set, The physical layer of the base station may determine the contention preamble and the useful non-contention preamble according to the identifier information of the preamble corresponding to the cell acquired from the upper layer, and obtain the reference root sequence information used to generate the contention preamble and the useful non-contention preamble without acquiring The reference root sequence information used to generate the useless non-competitive preamble, thereby generating a reference root sequence that is only relevant to the competitive preamble and the useful non-competitive preamble. In the embodiment of the present invention, when receiving the preamble signal sent by the UE in one cell, the physical layer of the base station detects only the root sequence corresponding to the partial preamble supported by the cell, instead of supporting the entire cell. The root sequence corresponding to the preamble is detected, which saves the detection processing resources and reduces the detection delay, thereby reducing the access delay and handover delay of the terminal.

The sequence used in the PRACH preamble in the embodiment of the present invention is a ZC (Zadoff-Chu) sequence, and the sequence obtained after cyclic shifting of the ZC sequence is still a ZC sequence. Therefore, the 64 preambles corresponding to each cell can be obtained by cyclic shifting of thousands of ZC 4艮 sequences. Different cell radius and different speed scenarios require different numbers of ZC root sequences. Generally speaking, the cell radius is large. In the high speed scene, the number of ZC root sequences required is large. At most, each cell needs 64 ZC root sequences to generate 64 preambles.

FIG. 2 is a schematic flowchart of a method for configuring a preamble according to Embodiment 2 of the present invention. As shown in FIG. 2, the method for configuring a preamble in this embodiment may include the following steps:

Step 201: The physical layer of the base station acquires channel parameter information of the PRACH and the identifier information of the preamble corresponding to the cell, where the preamble corresponding to the cell includes a contention preamble and a non-contention preamble, and the non-competitive preamble includes a useful non-competitive preamble and a useless non-competitive Competing for the lead.

The channel parameter information may include: a number of cyclic shifts Ncs, a channel configuration (PRACH Configuration), a root sequence start logical index, a speed scene (high-speed cell or low-speed cell) identifier, and frequency domain location information of the channel.

Before this step, in addition to the channel parameter information of the PRACH, the upper layer of the base station needs to set all the preambles (64 preambles) corresponding to the cell according to the number of UEs in the cell and the switching frequency of the UE. For the forefront, useful non-competitive predecessors and useless non-competitive predecessors. The specific predecessor setting method can be the following three ways:

method one:

Continuously setting the competitive leading and non-competitive predecessors, and continuously setting useful non-competitive predecessors and useless non-competitive predecessors, the preamble identification information may include the number of useful non-competitive predecessors, the starting of useful non-competitive predecessors Logical index

Method 2:

Continuously setting the competition for the leading and non-competitive predecessors, and discontinuously setting the useful non-competitive predecessor and the useless non-competitive predecessor, the preamble identification information may include the identification of the proactive leader, the identification of the useful non-competitive predecessor, and the useless The logo of the predecessor.

Method three: If the competitive predecessor and the non-competitive predecessor are not consecutively set, and the non-competitive predecessor and the useless non-competitive predecessor are not continuously set, the preamble identification information may include the logo of the proactive leader, the identification of the useful non-competitive predecessor, and uselessness. The logo of the non-competitive predecessor.

In the first method, since the predecessor and the non-competitive predecessor are continuously allocated, that is, the logical index of the predecessor and the non-competitive preamble are continuous, for example: the logical index number is 0-n The preamble is the predecessor, and the preamble with the logical index number n+1-63 is the non-competitive preamble. When dividing the non-competitive predecessor into a useful non-competitive predecessor and a useless non-competitive predecessor, the same method of continuous allocation is also adopted, and the fixed non-competitive predecessor is placed in front, that is, 64 predecessors are continuously assigned to compete. Leading, useful non-competitive predecessors and useless non-competitive predecessors. In this way, the upper layer of the base station can only send the number of useful non-competitive preambles and the starting logical index of the useful non-competitive preamble to the physical layer along with the channel parameter information of the PRACH.

In the second method and the third method, since the useful non-competitive predecessor and the useless non-competitive predecessor may be discontinuously allocated, that is, the logical index of the useful non-competitive predecessor and the useless non-competitive preamble is discontinuous, for example: The bitmap is used to identify the preamble, and the identifier of the preamble and the identifier of the useful non-competitive preamble may be required to be detected, and set to 1 (or 0), useless non-competitive preamble The identifier may be an unneeded detection flag indicating that detection is not required, and is set to 0 (or 1). A 64-bit length data can be used to identify the preamble and the preamble that need to be detected in the 64 preambles in the cell in a bitmap, as shown below.

bitO PreambleO

Bitl Preamblel bit62 Preamble62

Bit63 Preamble63 can also be expressed as: bitO Preamble63

Bitl Preamble62 Bit62 Preamblel

Bit63 PreambleO

You can set the bit to 0 to indicate that detection is required, set to 1 to indicate that no detection is required, or set bit 1 to require detection, and set to 0 to indicate that detection is not required.

In this embodiment, the base station sets all the preambles (64 preambles) corresponding to the cell as the competitive preamble, the useful non-competitive preamble, and the useless non-competitive preamble according to parameters such as the number of UEs in the cell and the handover frequency of the UE. The following principles can be adopted: For example, when the cell specification (cell radius and bandwidth) is unchanged, the number of competitive preambles and non-competitive preambles required by the cell is limited by the number of cell users when a certain user collision probability is met ( That is, the number of UEs and the number of accesses that need to be supported per second (the switching frequency of the UE), and when the number of users increases, the number of accesses that need to be supported per second increases, and the corresponding required leading numbers The number will also increase. Assuming that the number of cell users is 3000, the number of used and the number of non-competitive accesses that need to be supported per second are 36 times/second and 29 times/second, respectively, corresponding to the need for competitive lead and useful non-competitive predecessors. The number is 13 and 4 respectively, corresponding to 64-13-4=47 leading idles and becomes a useless non-competitive preamble; when the number of cell users drops to 1000, the number of accesses required to be supported per second is correspondingly reduced. Here, for the sake of simplicity, only the number of times of competitive access can be reduced, and the number of useful non-contention accesses remains unchanged. The number of required predecessors at this time will also be 1/3 of that of 3000 users. That is 5, then the number of useless non-competitive predecessors reached 64-5-4=55. According to the determined number of competitive predecessors, useful non-competitive predecessors and useless non-competitive predecessors, all the predecessors (64 preambles) corresponding to the cell are set to be competitive predecessors and useful non-exhaustions by any of the above methods. It is pointed out that the above examples are only for the purpose of helping understanding, and are not intended to limit the scope of protection of the present invention, and those skilled in the art also according to the number of UEs in the cell. The setting of the switching frequency of the UE is performed in other manners.

In this embodiment, after determining the number of competitive preambles and useful non-competitive preambles required by the cell, the number of useless non-competitive preambles can be obtained by combining all the preamble numbers corresponding to the cell. For example, in the example given above, the cell corresponds to all 64 preambles, and the number of competing predecessors and useful non-competitive preambles is 13 and 4 respectively, and the number of useless non-competitive preambles is 64-13- 4 = 47.

Step 202: The physical layer of the base station determines, according to the foregoing identification information, a corresponding competitive preamble and useful Not competing for the lead.

In this step, the physical layer can determine the number of the preamble and its starting logical index, the number of useful non-competitive preambles, and its starting logical index according to the preamble identification information. Or based on the prescriptive identification information, it can be determined which is the competition leader and which is the useful non-competition leader;

Step 203: The physical layer of the base station obtains reference root sequence information used to generate a contention preamble and a useful non-contention preamble according to the obtained channel parameter information of the PRACH, where the reference root sequence information includes the number of reference root sequences.

In this step, the physical layer calculates reference root sequence information corresponding to the contention preamble and the useful non-contention preamble according to the obtained channel parameter according to the obtained channel parameter, for example, the reference ZC root sequence information. The reference ZC root sequence information may include: a reference number of ZC root sequences, a number of cyclic shift sequences on each reference ZC root sequence, a position, a length, and a number of search windows corresponding to each cyclic shift sequence, etc. Parameter information.

If the number of ZC root sequences used to generate all the preambles corresponding to the cell is N, and the number of reference ZC root sequences is Ν', and both Ν and N' are positive integers greater than or equal to 1, the reference ZC root sequence is used. The number N' is less than or equal to 1\1.

Step 204: The physical layer of the base station generates a reference root sequence that the physical layer needs to detect according to the number of the reference root sequence and the root sequence start logical index in the channel parameter information of the PRACH.

In this step, the physical layer generates N' reference ZC root sequences that the physical layer needs to detect according to the number of reference ZC root sequences and the root sequence start logical index in the channel parameter information of the upper layer configuration, and saves them.

Step 205: The physical layer of the base station receives a preamble signal sent by the UE in the cell.

It is not difficult to understand that one or more UEs in the cell transmit a preamble to the base station through the air interface. If only one UE transmits the preamble, the preamble signal received by the base station includes the UE transmitting the preamble; if there are multiple UEs transmitting the preamble, the preambles sent by the UEs are superimposed to generate a preamble signal in the air interface, and the preamble signal received by the base station includes multiple Leading. In this embodiment, the preamble signal may be a PRACH preamble step 206. The physical layer of the base station detects the reference root sequence and the received preamble signal, and determines to generate a sequence of preambles included in the preamble signal.

In this step, the physical layer of the base station will receive the PRACH preamble signal and the locally stored N' The reference ZC root sequences are sequentially subjected to time domain correlation detection to obtain a plurality of related sequences. The search window corresponding to each cyclic shift sequence is determined by referring to the position, length and number of search windows corresponding to each cyclic shift sequence included in the ZC root sequence information. Using the detected correlation sequence, a peak search is performed in a search window corresponding to each cyclic shift sequence to complete PRACH detection. When the maximum value of the correlation energy in a search window exceeds the threshold value, determining a cyclic shift sequence corresponding to the search window, that is, a sequence for generating a certain preamble included in the preamble signal; when a search window is correlated When the maximum value of the energy does not exceed the threshold value, determining that the cyclic shift sequence corresponding to the search window is not generating a sequence of a preamble included in the preamble signal, or determining that the cyclic shift sequence is not included in the preamble signal Corresponding preamble.

The number N of reference ZC root sequences in this embodiment is smaller than the number N of generating all preamble ZC root sequences corresponding to the cell, and the physical layer of the base station receives the preamble sent by the UE in the cell. When the signal is received, only the root sequence of the partial preamble supported by the cell (Ν' reference ZC root sequence) is detected, instead of detecting the root sequence of all the preambles supported by the cell, which saves detection processing resources and reduces detection. Delay, thereby reducing the access delay and handover delay of the terminal.

The embodiment of the invention reduces the consumption of the physical layer detection resources of the base station, thereby reducing the detection delay of the physical layer. In the case that the number of terminal users in the cell is small, 64 preambles of a cell correspond to 64 root sequences (high-speed scene or low-speed scene). If 10 preambles can be allocated as useless non-competitive preambles, correspondingly, less detection can be performed. With 10 root sequences, the detection delay of the corresponding physical layer can be reduced by about 15%. In the Frequency Division Duplex (FDD) mode, there can be at most one PRACH per subframe. Therefore, under the above assumptions, the detection delay of the physical layer can be reduced by about 15%. In time division duplexing In the Time Division Duplex (TDD) mode, there can be at most 6 PRACHs per subframe, and each PRACH supports the same PRACH preamble. Therefore, under the above assumptions, each PRACH can reduce the detection delay by 15%. In this embodiment, the PRACH detection delay of the physical layer is reduced, so that the upper layer can send a RACH response (Response) message to the UE in advance, thereby reducing the access delay and handover delay of the terminal.

3 is a schematic structural diagram of a preamble configuration apparatus according to Embodiment 3 of the present invention. As shown in FIG. 3, the preamble configuration apparatus of this embodiment may include an identification module 31, a determination module 32, and an acquisition module 33. And processing module 34. The identifier module 31 is configured to obtain the identifier information of the preamble corresponding to the cell, where the preamble corresponding to the cell may include a competitive preamble and a non-competitive preamble, and the non-competitive preamble may include a useful non-competitive preamble and a useless non-competitive preamble. . The determining module 32 is configured to determine a corresponding competitive preamble and a useful non-competitive preamble according to the foregoing identification information acquired by the identification module 31. The obtaining module 33 is configured to obtain reference root sequence information, where the reference root sequence information is used to generate a competitive preamble and a useful non-competitive preamble determined by the determining module 32. The processing module 34 is configured to generate a reference root sequence according to the reference root sequence information acquired by the obtaining module 33.

The preamble configuration apparatus of this embodiment may be located within the base station, because the non-contention access preamble is mainly used for cell handover of the UE, and which preamble the UE uses may be specified by the upper layer of the base station. Therefore, the upper layer of the base station can set all PRACH preambles corresponding to the cell into three categories: competitive preamble, useful non-competitive predecessor, useless non-competitive predecessor. The base station only needs to select from the useful non-competitive predecessor when assigning the non-competitive preamble to the to-be-switched terminal. In addition to the channel parameter information of the PRACH, the upper layer of the base station needs to set all the preambles (64 preambles) corresponding to the cell to be competitive preambles according to parameters such as the number of UEs in the cell and the handover frequency of the UE. Non-competitive predecessors and useless non-competitive predecessors. The identity module may obtain the channel parameter information of the PRACH and the identifier information of the preamble corresponding to the cell from the upper layer of the base station.

Further, the configuration apparatus of the preamble of the embodiment may further include a setting module (not shown), configured to set the preamble corresponding to the cell to be competitive according to the number of UEs in the cell and the switching frequency of the UE. Leading, useful non-competitive predecessors and useless non-competitive predecessors, and set the identification information of the above various predecessors. The determining module 32 may determine the corresponding competitive preamble and the useful non-competitive preamble according to the foregoing identification information acquired by the identifying module 31, and the obtaining module 33 only obtains the reference root sequence information for generating the competitive preamble and the useful non-competitive preamble, instead of Then obtain the reference root sequence information for generating the useless non-competitive preamble. Processing module 34 generates a reference root sequence that is only relevant to the competitive leader and the useful non-competitive leader.

Further, the configuration device of the preamble of the embodiment may further include a receiving module 35 and a detecting module 36. The receiving module 35 receives the preamble signal sent by the terminal in the cell, and the detecting module 36 acquires a cyclic shift sequence according to the reference root sequence generated by the processing module 34, where the cyclic shift sequence is used to generate the preamble signal. The lead. The process by which the detection module 36 acquires the cyclic shift sequence can be seen in the description of the above embodiment, such as step 206. In this embodiment, when the receiving module 35 of the base station receives a preamble signal sent by the UE in the cell, the detecting module 36 only uses the cell. The root sequence of the supported partial preamble is detected, instead of detecting the root sequence of all the preambles supported by the cell, which saves the detection processing resources and reduces the detection delay, thereby reducing the access delay and handover delay of the terminal. .

The embodiment of the present invention may further provide a base station, including the foregoing preamble configuration apparatus in Embodiment 3 of the present invention.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

It should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: The technical solutions described in the foregoing embodiments are modified, or some of the technical features are equivalently replaced; and the modifications or substitutions do not deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

Rights request

A preamble configuration method, comprising:

Acquiring the identifier information of the preamble corresponding to the cell, where the preamble corresponding to the cell includes a competition preamble and a non-competition preamble, and the non-competition preamble includes a useful non-competition predecessor and a useless non-competition preamble;

Determining, according to the identifier information, a contention preamble and a useful non-contention preamble corresponding to the cell; acquiring reference root sequence information that generates the contention preamble and the useful non-contention preamble; generating a reference root according to the reference root sequence information sequence.

2. The method according to claim 1, further comprising:

Receiving a preamble signal sent by a terminal in the cell;

A sequence for generating a preamble included in the preamble signal is obtained according to the reference root sequence.

The method according to claim 1 or 2, further comprising: setting, according to the number of terminals in the cell and the switching frequency of the terminal, a preamble corresponding to the cell as a competitive preamble, a useful non- Competing for the lead and useless and non-competitive.

The method according to claim 3, wherein the preamble corresponding to the cell is set as a competitive preamble and a useful non-competitive preamble according to the number of terminals in the cell and the switching frequency of the terminal. And useless non-competitive predecessors include:

And continuously setting the competitive preamble and the non-competitive preamble according to the number of terminals in the cell and the switching frequency of the terminal, and continuously setting the useful non-competitive preamble and the useless non-competitive preamble, The identification information includes the number of useful non-competitive preambles, and a starting logical index of the useful non-competitive preamble.

And setting the competitive preamble and the non-competitive predecessor according to the number of terminals in the cell and the switching frequency of the terminal, and discontinuously setting the useful non-competitive preamble and the useless non-competitive preamble, The identification information includes an identifier of the competitive preamble, an identifier of the useful non-competitive preamble, and an identifier of the useless non-competitive preamble.

The method according to claim 3, wherein the according to the terminal in the cell The number and the switching frequency of the terminal set the preamble corresponding to the cell as a competitive preamble, a useful non-competitive preamble, and a useless non-competitive preamble include:

Discontinuously setting the contention preamble and the non-contention preamble according to the number of terminals in the cell and the switching frequency of the terminal, and discontinuously setting the useful non-competitive preamble and the useless non-competitive preamble The identifier information includes an identifier of the competitive preamble, an identifier of the useful non-competitive preamble, and an identifier of the useless non-competitive preamble.

The method according to claim 5 or 6, wherein the identifier of the competition preamble and the identifier of the useful non-competitive preamble indicate that detection is required, and the identifier of the useless non-competitive preamble includes No testing is required.

8. A preamble configuration device, comprising:

The identifier module is configured to obtain the identifier information of the preamble corresponding to the cell, where the preamble corresponding to the cell includes a contention preamble and a non-competition preamble, and the non-competition preamble includes a useful non-competition preamble and a useless non-competition preamble;

An obtaining module, configured to obtain reference root sequence information, where the reference root sequence information is used to generate a competitive preamble and a useful non-competitive preamble determined by the determining module;

9. The device according to claim 8, further comprising:

a receiving module, configured to receive a preamble signal sent by a terminal in the cell;

And a detecting module, configured to acquire, according to the reference root sequence generated by the processing module, a sequence for generating a preamble included in the preamble received by the receiving module.

The device according to claim 8 or 9, further comprising: a setting module, configured to set a preamble corresponding to the cell to be actual according to the number of terminals in the cell and the switching frequency of the terminal For the forefront, useful non-competitive predecessors and useless non-competitive predecessors.

A base station, characterized by comprising the former according to any one of claims 8 to 10.