KR20100010014A - Method for transmitting and acquiring cell id information - Google Patents

Abstract

PURPOSE: A cell ID transmitting and receiving method is provided to search for the whole cell ID information in multiple stages. CONSTITUTION: A first synchronous channel signal and a second synchronous channel signal are received. The first synchronous channel signal includes first indexes. The second synchronous channel signal includes second indexes which indicate cell ID by combination with the first index and are grouped corresponding to the number of the first indexes. The first index value is estimated using the first synchronous channel signal. The second index is estimated from the second index group corresponding to the first index value using the second synchronous channel signal.

Description

Transmission and Acquisition Method of Cell ID Information {METHOD FOR TRANSMITTING AND ACQUIRING CELL ID INFORMATION}

The following description relates to the transmission of cell ID information and the acquisition of cell ID information using the same for solving the inter-cell ambiguity problem through a synchronization channel of a mobile communication system.

The cell ID (or cell identification information) refers to an identifier for identifying a cell having a specific location area in a wireless network. The specific location area here coordinates radio related tasks within the coverage area and includes at least one base station (BTS or Node B) that provides a connection over the air interface between the network and the mobile station (or UE). The base station (BTS, Node B or eNode B) described above is an access point for indoor or outdoor coverage.

Such a cell ID may be represented by using two sub-sync channels. In the present technology, the cell ID information to be transmitted is divided and transmitted through two lower synchronization channel signals, thereby allowing the terminal to acquire the full cell ID information in stages. This method reduces the number of hypotheses tests that the terminal must perform by acquiring cell ID information in stages instead of performing hypotheses tests corresponding to the total number of cell IDs at once. This has the effect of reducing the complexity of the terminal.

For example, assume that the total number of cell ID information that one sync channel needs to transmit is 510. There are two sub-sync channels (sub-sync channel 0 and sub-sync channel 1) in one sync channel, Nid0 partial cell ID information in sub sync channel 0, and Nid1 parts in sub sync channel 1 Assume that cell ID information is transmitted. In this case, a total of Nid (= Nid0 * Nid1) cell ID information may be transmitted through one sync channel, and the Nid information may transmit a total of 510 total cell ID information.

For example, Nid0 = 3 and Nid1 = 170 may be set to transmit a total of 510 (= 3 * 170) cell ID information. According to the above example, the UE is required to perform three hypothesis tests on the lower synchronization channel 0 and 170 hypothesis tests on the lower synchronization channel 1. According to the present method, it is possible to acquire all cell ID information by only 173 (= 3 + 170) correlation operations that the UE should perform 510 correlation operations in order to obtain all cell ID information, and about 33.9% Can reduce the amount of computation.

However, in the method of dividing and transmitting cell ID information into two lower synchronization channels as described above, the following ambiguity problem may occur.

1 is an example of cell arrangement for explaining the ambiguity problem occurring in a method of dividing and transmitting cell ID information into two lower synchronization channels.

In the case of FIG. 1, it is assumed that the number of lower synchronization channels is two as in the above-described example. In addition, it is assumed that the total number of cell IDs is 510, the number of partial cell ID information transmitted on the lower synchronization channel 0 is three, and the number of partial cell ID information transmitted on the lower synchronization channel 1 is 170. Under this assumption, it is assumed that the cell ID information combination is represented as (index information of lower sync channel 0, index information of lower sync channel 1). Then, it has a range of 0 <= index information of lower sync channel 0 <= 2, 0 <= index information of lower sync channel 1 <= 169.

In Fig. 1, cell ID information of (0, 1) is shown in segment α of BS 0, cell ID information of (1, 3) is shown in segment β of BS 2, and cell (0, 2) is shown in segment γ of BS 1. It is assumed to have ID information. In this case, there are six combinations of cell ID information that can be received by the MS.

(0,1), (0,2), (0,3), (1,1), (1,2) , (1,3)

Among these, combinations of (0, 3), (1, 1), and (1, 2) shown in bold font are signals that are not actually transmitted from the base station in this example. Such a signal corresponds to a combination generated because different cell ID information combinations are mixed with each other and received by the terminal. For example, in the case of (0, 3), 0 out of ( 0 , 1) from BS 0 segment α and 3 out of (1, 3 ) from BS 2 segment β are combined to generate a false alarm to the terminal. It is to bring about.

Therefore, while maintaining the advantages of using the two lower synchronization channels as described above, a technique for preventing the ambiguity problem described above is required.

According to an aspect of the present invention for solving the above problems, in the method for acquiring cell ID information, a cell ID is represented by a first synchronization channel signal including a first index and a combination with the first index. Receiving a second synchronization channel signal comprising a second index grouped into a number of groups corresponding to the number of first indexes; Estimating the first index value using the received first sync channel signal; And estimating the second index within the second index group corresponding to the estimated first index value by using the received second sync channel signal.

In this case, the cell ID may be specified according to the second index. In addition, each of the first indexes may have a one-to-one relationship with each of the second index groups.

The second index may correspond to one code sequence or may correspond to a code sequence generated by a combination of two different sequences.

In addition, the first synchronization channel signal may be a primary synchronization channel (P-SCH) signal, and the second synchronization channel signal may be a secondary synchronization (S-SCH) channel signal.

According to another aspect of the present invention, there is provided a method for transmitting cell ID information, the method comprising: selecting a first index and transmitting a first synchronization channel signal including the selected first index; And selecting a second index grouped in groups of a number corresponding to the number of the first indexes by combining the first index with a cell index, thereby obtaining a second sync channel signal including the selected second index. A method of transmitting cell ID information, comprising the step of transmitting, is proposed.

In still another aspect of the present invention, in a terminal for acquiring cell ID information, a first sync channel signal including a first index and a combination of the first index and a cell ID are used to represent a cell ID. A receiver for receiving a second sync channel signal comprising a second index grouped into a number of groups corresponding to the number; A storage module for storing information about the second index group corresponding to the first index value; And estimating the first index value by using the first sync channel signal received by the receiver, and corresponding to the estimated first index value by using the received second sync channel signal. A terminal including an index value searcher for estimating the second index in a stored second index group is proposed.

In terms of computation, two or more cell ID information combinations are mixed with each other, while maintaining the advantage of reducing the computation amount by searching the entire cell ID information in stages instead of searching all the cell ID information at once, compared to conventional cell ID detection. This has the advantage of not occurring.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below in conjunction with the appended drawings is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details to assist in a thorough understanding of the present invention. However, those skilled in the art will appreciate that the invention may be practiced without these specific details. For example, the following description will focus on certain terms, but need not be limited to these terms and may refer to the same meaning even when referred to as any term.

In some instances, well-known structures and / or devices may be omitted in order to avoid obscuring the concepts of the present invention, and may be represented in the form of block diagrams and / or flowcharts showing the core functions of each structure and / or device. have. In addition, the same components will be described with the same reference numerals throughout the present specification.

The following embodiments are a combination of the components and features of the present invention in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be embodied in a form that is not combined with other components or features. It is also possible to combine some of the components and / or features to form an embodiment of the invention. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment.

In this document, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a terminal. Here, the base station has a meaning as a terminal node of the network that directly communicates with the terminal. The specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases. That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the term "terminal" may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

In an aspect of the present invention described below, it is proposed to set to satisfy the following matters.

1. The sequence index transmitted on the lower synchronization channel 1 has a one-to-many correspondence with the sequence index transmitted on the lower synchronization channel 0.

2. The sequence index transmitted on the lower synchronization channel 0 has a one-to-one relationship with the group index grouping the sequence index transmitted on the lower synchronization channel 1.

That is, the sequence index transmitted on the lower synchronization channel 0 indicates the entire cell ID information together with the sequence index transmitted on the lower synchronization channel 1. In addition, the present embodiment proposes to set the sequence indexes transmitted on the lower synchronization channel 1 to be grouped into groups of the number corresponding to the number of sequence indexes transmitted on the lower synchronization channel 0. Accordingly, the present embodiment proposes that the sequence index transmitted on the lower synchronization channel 0 corresponds to each one of the sequence index groups transmitted on the lower synchronization channel 1.

The concrete example will be described as follows.

One of the Nid0 sequence indexes may be selected and transmitted through the lower synchronization channel 0. It is assumed that each sequence index has a value in the range of 0 to Nid0-1. One of the sequence indexes of Nid1 can be selected and transmitted through the lower synchronization channel 1, and each sequence index is assumed to have a value in the range of 0 to Nid1 -1. Therefore, the number of cell ID information that can be transmitted through two lower synchronization channels is Nid0 * Nid1. In this case, it is assumed that the "sequence index" includes not only a physical index for a substantial sequence but also a logical index having a specific relationship with the physical index.

Under these assumptions, FIG. 2 is a diagram for describing a method for setting a relationship between sequence indices transmitted through two lower synchronization channels according to an embodiment of the present invention. In FIG. 2, it is assumed that Nid0 ≦ Nid1, but it is apparent to those skilled in the art that the relationship between both sequence indices may be set in the same manner even when Nid0 ≧ Nid1.

Specifically, according to the example of FIG. 2, when the sequence index no transmitted through the lower synchronization channel 0 is 0, the sequence index n1 transmitted through the lower synchronization channel 1 has a value within the range of 0 to Nid1 / Nid0 −1. Can be. When the sequence index no transmitted through the lower synchronization channel 0 is 1, the sequence index n1 transmitted through the lower synchronization channel 1 may be one value within the range of Nid1 / Nid0 to 2Nid1 / Nid0-1. Similarly, when n0 = 2, n1 may be a value within a range of 2Nid1 / Nid0 to 3Nid1 / Nid0-1. In the example of FIG. 2, the case where Nid1 is divided by Nid0 is described as an example. However, when Nid1 is not divided by Nid0, each sequence index group transmitted through the lower synchronization channel 1 has floor (Nid1 / Nid0) indexes. It will be apparent to those skilled in the art that the present invention can be set in such a way that the same method can be applied.

As described above, in the present embodiment, since the sequence index transmitted through the lower synchronization channel 1 is grouped and set in advance between the transmitting and receiving end to have a one-to-one relationship with the sequence index transmitted through the lower synchronization channel 0, as described above, When different cell ID information combinations are mixed, the mixed cell ID combination is not included in the preset cell ID combination, thereby solving the ambiguity problem described above.

In this case, n0 may define Nid0 sequences and n1 may define Nid1 sequences. Further, Nid0 and Nid1 pieces of information may be transmitted through the lower sync channel 0 and the lower sync channel 1, respectively, and the total number of cell ID information delivered is Nid1. That is, each of all cell ID information may be specified by an index of n1.

In this embodiment, the sequence of n1 may correspond to the terminal sequence code. Also, the sequence of n1 may be defined as a combination of two or more code sequences.

In the system as described above, the terminal may first detect a code of n0 under the assumption of Nid0. For example, the terminal may detect an index value of n0 by performing detection according to a maximum likelihood (ML) scheme. Thereafter, when the UE wants to detect the index received through the lower synchronization channel 1, the UE may attempt to detect only the index group corresponding to the n0 index value among the Nid1 n1 index groups. The second index search may also be the ML method described above. By using this method, the amount of ML search operations for detecting the n1 index by the UE is reduced to N_id2 / N_id1.

Hereinafter, as another aspect of the present invention, a sequence and a physical mapping that are transmitted on each lower sync channel will be described.

In the above example, when cell ID information is configured and transmitted in two sets, each sub-sync channel signal is mapped in two ways: localized mapping and interleaved mapping to the physical resource region as follows. Can be sent.

3 and 4 illustrate a method of mapping two sync channel signals to a physical sync channel region in accordance with an embodiment of the present invention.

Here, it is assumed that the amount of resources (eg, the number of subcarriers or the sequence length) allocated to each of "sub-sync0" and "sub-sync1" is the same, but different cases will be described below by the same principle. The mapping method described can be applied. In detail, FIG. 3 illustrates a method of mapping a signal of sub-synchronous channel 0 and a signal of sub-synchronous channel 1 according to a local mapping method, and FIG. 4 illustrates a signal of sub-synchronous channel 0 and a signal of sub-synchronous channel 1 according to an interleaving method. The method of mapping is shown.

In addition, for convenience, a total of 512 cell IDs are defined, and it is assumed that three partial cell IDs are transmitted in the lower sync channel 0 and 170 partial cell IDs in the lower sync channel 1. In addition, the sequence length allocated to each lower synchronization channel may be any.

In general, for the system described above, only three sequence sets may be defined as the sequence for the lower synchronization channel 0, and only 170 sequence sets may be defined as the sequence for the lower synchronization channel 1. However, in the above-described embodiment of the present invention, three sequence sets are defined as the sequence for the lower synchronization channel 0, and 510 (= the number of information required for the lower synchronization channel 1 * the lower synchronization channel) are defined as the sequence for the lower synchronization channel 1. A sequence set of 0) is defined and used. At this time, the sequence set defined in the lower synchronization channel 0 and the lower synchronization channel 1 may be defined identically or differently.

The UE needs only to find 170 partial cell IDs according to a predetermined group without finding all 510 in the lower synchronization channel 1.

In terms of computation, it compares with detecting the existing cell ID of 510. In the case of transmitting 510 cell IDs in the related art, 510 correlation operations are required, and when a sequence length is N, a total of 510 * N complex addition operations are required. However, if the present embodiment is applied, only the complex summation operations of the lower synchronization channel 0 and the lower synchronization channel 1 and 170 times, that is, the total 173 complex summation operations are required.

In terms of performance, it is compared with the conventional simple two-set structure approach.

The amount of computation is the same in both cases requiring 173 complex summations.

However, in the simple two-set structure, the above-described cell ambiguity problem occurs, whereas the above-described cell-cell ambiguity problem does not occur.

It looks at the structure of the terminal for performing the function as described above.

5 is a diagram schematically illustrating a terminal structure according to an embodiment of the present invention.

According to the embodiments described above, a terminal for acquiring cell ID information includes a storage module 502 for storing a relationship between a receiver 501 for receiving a synchronization channel, a lower synchronization channel signal 0, and a lower synchronization channel signal 1; The sub-sync channel signal 0 and the sub-sync channel signal 1 are detected by using the received signal of the receiver 501 and the mapping relationship stored in the storage module 502, and an index value searcher 503 for obtaining cell ID information. In detail, the receiver 501 receives n0 included in the lower synchronization channel 0 and n1 included in the lower synchronization channel 1. Meanwhile, n1 is grouped into a group corresponding to n0, and such grouping information is previously stored in the storage module 502.

In this way, n0 and n1 received by the receiver 501 are transferred to the index value searcher 503, and the index value searcher 503 detects the index of the lower synchronization channel 0 from n0, and the n1 group corresponding to the n0 value. Detects the n1 index value received in the.

Meanwhile, the method as described above may be applied to the following frame structure.

6 is a diagram illustrating a frame structure according to another embodiment of the present invention.

In FIG. 6, SCH type 1 may be the above-described sub-sync0 and SCH type 2 may be sub-sync 1. In addition, SCH type 1 and SCH type 2 may correspond to P-SCH and S-SCH, respectively.

The detailed description of the preferred embodiments of the invention disclosed as described above is provided to enable any person skilled in the art to make and practice the invention. Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. I can understand that you can.

Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

As described above, the present invention can be applied to various wireless communication systems for transmitting cell ID information through a synchronization channel.

1 is an example of cell arrangement for explaining the ambiguity problem occurring in a method of dividing and transmitting cell ID information into two lower synchronization channels.

2 is a diagram for describing a method of setting a relationship between sequence indices transmitted through two lower synchronization channels according to an embodiment of the present invention.

3 and 4 illustrate a method of mapping two sync channel signals to a physical sync channel region in accordance with an embodiment of the present invention.

5 is a diagram schematically illustrating a terminal structure according to an embodiment of the present invention.

6 is a diagram illustrating a frame structure according to another embodiment of the present invention.

Claims (12)

In the method for obtaining cell ID information, A second synchronization channel signal including a first synchronization channel signal including a first index, and a second index representing a cell ID by combination with the first index and grouped into a group of a number corresponding to the number of the first indexes Receiving; Estimating the first index value using the received first sync channel signal; And Estimating the second index within the second index group corresponding to the estimated first index value using the received second sync channel signal. The method of claim 1, And the cell ID is specified according to the second index. The method of claim 1, And each of the first indexes has a one-to-one relationship with each of the second index groups. The method of claim 1, And the second index corresponds to one code sequence. The method of claim 1, And wherein the second index corresponds to a code sequence generated by a combination of two different sequences. The method of claim 1, And the first sync channel signal is a main sync channel signal and the second sync channel signal is a sub sync channel signal. In the method for transmitting cell ID information, Selecting a first index to transmit a first sync channel signal including the selected first index; And Transmit a second synchronization channel signal including the selected second index by selecting a second index grouped into a group of a number corresponding to the number of the first indexes by indicating a cell ID in combination with the first index. And transmitting the cell ID information. The method of claim 7, wherein And the cell ID is specified according to the second index. The method of claim 7, wherein And the second index corresponds to one code sequence. The method of claim 7, wherein And the second index corresponds to a code sequence generated by a combination of two different sequences. The method of claim 7, wherein And the first sync channel signal is a main sync channel signal, and the second sync channel signal is a sub sync channel signal. In the terminal for obtaining cell ID information, A second synchronization channel signal including a first synchronization channel signal including a first index, and a second index representing a cell ID by combination with the first index and grouped into a group of a number corresponding to the number of the first indexes A receiver for receiving; A storage module for storing information about the second index group corresponding to the first index value; And Estimating the first index value using the first sync channel signal received by the receiver, and corresponding to the estimated first index value using the received second sync channel signal to the storage module. And an index value finder for estimating the second index in the stored second index group.

Images