KR100915005B1 - Method for transmitting Broadcasting signal and random access preamble - Google Patents

Abstract

The present invention relates to a broadcast signal transmission method and a random access preamble transmission method.

In the present invention, the base station transmits the broadcast signal by including the map index to the mobile station so that the mobile station can select the message map used for the preamble transmission according to the cell characteristics of the base station. Upon receipt of the message, the mobile station selects a message map suitable for the characteristics of the cell to which the current mobile station belongs, and configures and transmits a random access preamble using the selected message map.

Description

Broadcast signal transmission method and random access preamble transmission method {Method for transmitting Broadcasting signal and random access preamble}

The present invention relates to a broadcast signal transmission method and a random access preamble transmission method. In particular, the present invention relates to a method of transmitting a broadcast signal by a base station and a method of transmitting a random access preamble by receiving a mobile station.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. .

When a conventional mobile communication system wants to request an uplink resource through transmission of a random access preamble, the mobile station configures the preamble using a fixed message map.

As such, when a preamble is configured using a fixed message map for all cells, initial access, resource request, handover, and resynchronization are performed according to cell characteristics. There is a problem that it is difficult to reflect that the frequency of occurrence of random access, which occurs due to -synchronization), is different.

The present invention provides a method for configuring an efficient random access preamble according to cell characteristics to be achieved and a method for transmitting broadcast signals of a base station.

Broadcast signal transmission method of the base station for achieving the above object,

Associating an index of a message map corresponding to a characteristic of a cell managed by the base station among a plurality of message maps, each message map corresponding to characteristics of one or more cells; And transmitting the broadcast signal including the index to the mobile station.

In addition, the random access preamble transmission method of a mobile station according to another aspect of the present invention,

Receiving a broadcast signal including a message map index; And transmitting a random access preamble using a message map corresponding to the message map index among a plurality of stored message maps, each message map corresponding to characteristics of one or more cells.

According to an embodiment of the present invention, a base station transmits an index of a message map that matches cell characteristics to a mobile station, and the mobile station uses a message map selected by the base station as appropriate for the current cell. By configuring and transmitting a random access preamble, according to cell characteristics, a random access collision probability can be lowered by allocating more random IDs to connection reasons with high frequency.

1 is a flowchart illustrating a random access process according to an embodiment of the present invention.

2 is a diagram illustrating an example of a message map used for configuring a random access preamble according to an embodiment of the present invention.

3 is a diagram illustrating another example of a message map used for configuring a random access preamble according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

In this specification, a mobile station (MS) is a terminal, a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment (User Equipment). It may also refer to a user equipment (UE), an access terminal (AT), and the like, and may include all or some functions of a mobile terminal, a subscriber station, a portable subscriber station, a user device, and the like.

In the present specification, a base station (BS) is an access point (AP), a radio access station (Radio Access Station, RAS), a Node B (Node B), a base transceiver station (Base Transceiver Station, BTS), MMR ( Mobile Multihop Relay) -BS and the like, and may include all or part of functions such as an access point, a radio access station, a Node B, a base transceiver station, and an MMR-BS.

Hereinafter, a method of transmitting a broadcasting signal of a base station and a method of transmitting a random access preamble of a mobile station according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a random access process between a mobile station 100 and a base station 200 according to an embodiment of the present invention.

Referring to FIG. 1, the base station 200 periodically transmits a broadcasting channel (BCH) signal, which is a broadcast signal (S101). The BCH signal transmits system specific information necessary for the mobile station 100 to communicate with the base station 200, and the system related information is required for the mobile station 100 to transmit a random access preamble. A sequence index, a cyclic shift value, and a message map index. Here, the message map index includes the index of the message map selected according to the characteristics of the cell to which the base station 200 belongs. In this case, the message map index uses a predetermined message map index according to the characteristics of the cell managed by the base station 200, or the base station controller (not shown) transmits a message map index suitable for the cell managed by the base station 200. If so, the base station 200 may receive and use it.

Meanwhile, the mobile station 100 receiving the BCH transmits a random access preamble using the message map corresponding to the message map index included in the BCH signal (S102). That is, the mobile station 100 stores a plurality of message maps, and uses the message map corresponding to the message map index transmitted by the base station 200 to randomly access the mobile station 100 and cause downlink. A random access preamble including channel quality information (CQI) is configured and transmitted to the base station 200.

On the other hand, the base station controller (not shown) stores the same message map as the message map stored in the mobile station 100, and shares the index of each message map. Accordingly, when the base station control apparatus or the base station 200 selects a message map suitable for cell characteristics to the mobile station 100 and transmits an index of the selected message map to inform the mobile station 100 of the mobile station 100, the mobile station 100 transmits the index through the corresponding index. Alternatively, the random access preamble may be transmitted by using the same message map selected by the base station 200.

2 is a diagram illustrating an example of a message map used for configuring a random access preamble according to an embodiment of the present invention.

Referring to FIG. 2, the message maps used in the urban cell 300 and the highway neighboring cell 400 may be different from each other.

In the case of the urban cell 300, the handover request rate of the mobile stations 100 is smaller, and the initial access and resource request rate are higher than those of the neighboring highway 400. Accordingly, the message map 310 used in the urban cell 300 allocates more random IDs to initial access and resource requests than the message map 410 used in the highway neighboring cell 400. In addition, since the neighboring highway 400 has a higher handover request rate of the mobile stations 100 than the urban cell 300, the highway neighboring cell 400 allocates more random IDs to the handover than the message map of the urban cell 300.

In general, the random access preamble is transmitted in a 6-bit message. Therefore, 64 types of random access preambles can be transmitted by the mobile station 100. If each preamble is referred to as one random ID, as shown in FIG. 2, one message map 310 or 410 may be represented by 64 random IDs, and the random IDs may be used for the connection of the mobile station 100 and It is classified according to channel quality information (CQI).

The message map 310 of the urban cell 300 allocates 18 random IDs for the case that the access reason of the mobile station 100 is initial access, which is again good channel condition according to the channel state information. Eight are assigned to Good and ten are assigned to Bad channels. For resource request, the same method as for the initial connection described above is used if the reason for connection is a resource request and the channel condition is good, and if the reason for connection is a resource request and the channel condition is not good, 10 Is assigned a random ID. On the other hand, since the request rate in the urban cell 300 is higher in the case of the initial access and resource request than the neighboring cell 400 of the highway, the message map 310 used in the urban cell 300 provides an initial access and resource request. In order to allocate more random IDs than the message map 410 used in the highway neighboring cell 400.

In the case of the highway neighboring cell 400, 40 random IDs are allocated for handover in the message map 410. This is more allocated than the 24 of the message map 310 used in the urban cell 300, and the ratio of handover requests of the mobile stations 100 to the cell around the highway 400 is higher than that of the urban cell 300. It reflects high characteristics.

3 is a diagram illustrating another example of a message map used for configuring a random access preamble according to an embodiment of the present invention.

3 illustrates an example of configuring a message map by separating a connection reason having a high request rate and other remaining connection reasons according to characteristics of each cell.

For example, in the urban cell 300, since the ratio of initial access is high, the message map 320 classifies the access reason into only an initial access and a non-initial access. 32 random IDs are assigned to requests that are not initially connected. When the random ID is allocated in this manner, the mobile station 100 can transmit the random access preamble in a 6-bit message, so that 1 bit of information can be used to indicate a connection reason. That is, the mobile station 100 may notify the base station 200 by using only one bit of information whether the connection reason of the mobile station 100 is an initial connection or a request rather than an initial connection.

In addition, since the ratio of handover is high in the highway neighboring cell 400, the reason for connection is classified in the message map 420 as hand-over and non-hand-over only. Random IDs are allocated. In this case, since the mobile station 100 can transmit the connection reason to the base station 200 with one bit of information as in the above-described urban cell 300, the complexity of the message map is reduced.

As described above, when the base station 200 notifies the mobile station 100 of the message map suitable for the characteristics of the cell to which the current mobile station 100 belongs, the mobile station 100 randomly accesses the message map. The method of transmitting the preamble has an effect of lowering the probability of random access collision of the mobile station 100 by assigning more random IDs to the reason for the occurrence of frequent access.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (12)

In the broadcast signal transmission method of the base station, Transmitting, to a mobile station, a broadcast signal including an index of a message map selected according to characteristics of a cell managed by the base station among a plurality of message maps having different numbers of random IDs allocated for each connection reason; And Receiving a random access preamble configured from the mobile station using the message map corresponding to the index Broadcast signal transmission method comprising a. delete The method of claim 1, And the index is received from the base station control apparatus. The method of claim 1, The index is a broadcast signal transmission method using a preset value corresponding to the characteristics of the cell managed by the base station. The method of claim 1, And a method of allocating a random ID of each message map included in the plurality of message maps. The method of claim 1, And a method of classifying connection reason of each message map included in the plurality of message maps. In the random access preamble transmission method of a mobile station, Selecting a message map corresponding to a message map index included in a broadcast signal received from a base station among a plurality of message maps having different numbers of random IDs allocated for each connection reason; And Transmitting a random access preamble generated based on random ID classification information included in the selected message map Random access preamble transmission method comprising a. The method of claim 7, wherein And the message map index is an index corresponding to a message map selected from the plurality of message maps according to the characteristics of the cell in which the mobile station is located. delete The method of claim 8, Each message map included in the plurality of message maps has a different method of classifying connection reasons according to characteristics of a corresponding cell. The method of claim 7, wherein And the random access preamble includes one bit information corresponding to a connection reason of the mobile station. The method of claim 11, And wherein the one bit information indicates whether the connection reason corresponds to a connection reason having a maximum frequency in a cell in which the mobile station is located.