KR100437646B1 - Spread code allocate and cancellation method that use spread code management method through double state management of plane tree structure - Google Patents

Abstract

The present invention relates to a spreading code management method through dual state management of a planar tree structure, a spreading code allocation and release method using the same, and a computer-readable recording medium recording a program for implementing the methods. In order to implement efficient OVSF code allocation and release in the control station of (UTRAN), the storage structure of OVSF codes is organized into a one-dimensional array, and the double state management of each code eliminates the complicated search process when allocating and releasing, to provide. To this end, in order to satisfy the law of allocation of spreading codes, each spreading code is divided into two fields for dual management. The first status field indicates whether it is used, the second status field indicates whether it is available, and the spreading state. By managing the resources of the code tree in a flat tree structure of one-dimensional array, when accessing the lower spreading codes and the upper spreading codes, the index of the array is directly accessed without additional link information or retrieval process.

Description

Spread code allocate and cancellation method that use spread code management method through double state management of plane tree structure}

The present invention relates to a spreading code management method through dual state management of a planar tree structure in a wireless communication control station, a spreading code allocation / deletion method using the same, and a computer-readable recording medium recording a program for implementing the methods. For the channelization of downlink channels in a control station of a next generation mobile communication network (UTRAN: UTMS Terrestrial Radio Access Network) such as International Mobile Telecommunication (IMT-2000) and Universal Mobile Telecommunications System (UMTS) A method of allocating and freeing orthogonal variable spreading factor (OVSF) codes used. At this time, in order to induce a real-time call processing process and provide an efficient and simple OVSF code management method, a planar tree structure through dual state management is introduced to manage allocation and release of OVSF codes.

1 is an exemplary configuration diagram of a general wireless communication system, and shows an asynchronous mobile communication system (UTRAN), which is a mobile station (UE) 10, an asynchronous radio access network (RAN) 20, and A wireless communication core network (eg, GSM-MAP core network) 50 is organically connected and configured.

Asynchronous mobile communication system (UTRAN) is composed of a plurality of asynchronous radio access network (RAN) 20 connected to the wireless communication core network 50 through the Iu interface.

In Fig. 1, " Iu " is an interface between the radio communication core network 50 and an asynchronous radio access network (RAN) 20, and " Iur " is a control station of the asynchronous radio access network (RAN) 20. RNC: logical interface between Radio Network Controller (40) 40, and " Iub " represents an interface between control station (RNC) 40 and base station (Node-B) 30, respectively. On the other hand, "Uu" represents an air interface between an asynchronous radio access network (RAN) 20 and a user equipment (UE) 10. Here, a base station (Node-B) 30 is a logical node that is responsible for radio transmission and reception from one or more cells to a mobile station (UE) 10.

An asynchronous radio access network (RAN) 20 is composed of a control station (RNC) 40 and a base station (Node-B) 30, each base station (Node-B) 30 is one or more cells (Cell) Is connected to the control station (RNC) 40 through the Iub interface.

The control station (RNC) 40 performs the combination / splitting function during the handover between the base stations (Node-B) 30, and the combination / splitting in the case of the inter-cell handover in the same base station (Node-B) 30. The function may be performed by the control station (RNC) 40 or may be performed by the base station (Node-B) 30.

Here, a method of allocating and releasing an OVSF code used for channelization of downlink channels is performed in a call control processor in a control station (RNC) 40 of an asynchronous radio access network (RAN) 20.

The control station (RNC) 40 of the asynchronous radio access network (RAN) 20 ensures orthogonality of downlink channels by spreading to OVSF codes, and OVSF codes are orthogonal to each other using repetition and inversion of one higher code. Has the feature of generating two subcodes.

As shown in FIG. 2, in general, the number of orthogonal codes varies according to a spreading factor (SF) code, and codes of the same spreading factor are orthogonal to each other and all codes connected to the same branch are different. They are not orthogonal to each other. For example, C _4,1 and C _4,2 are orthogonal to each other, but C _4,1 and C _8,2 are not orthogonal.

When the OVSF code tree is viewed as a binary tree structure, each node can be regarded as a spreading code and a degree as a spreading factor. In addition, each node having the same order is orthogonal to each other, and the higher the order, the higher the diffusion coefficient.

The principle of OVSF code allocation is that the code must match the required spreading factor and be orthogonal to the channels in use. Therefore, when one code is assigned, not only the node representing the code but also the codes of all the child nodes whose node is the parent node and the codes of the parent node of the node cannot be used at the same time.

3 shows a rule when allocating an OVSF code, and FIG. 4 shows a manner when releasing an OVSF code.

3A shows a state of a code tree to which a code having a diffusion coefficient of 8 is assigned. For example, if code C _8,1 is assigned, the higher codes C _4,1 and C _2,1 and C _1,1 cannot be used until this code is released.

(B) of Fig. 3 is a C _4,1 is not available, assigning a C _4,2 geotinde showing a state of assignment of the code spreading factor of 4 from the state of (a) of Figure 3, the spreading factor is 4 Done. At this time, in order to ensure orthogonality, the lower codes C _8,3 and C _8,4 of C _4,2 cannot be used.

3C and 3D also show correct assignment states in the same manner.

Figure 4 shows the release process step by step, showing that the available code varies according to the release order.

(B) of Fig. 4, the continued even after the release of the code C _8,2 While not use a higher code C _4,1 and C _2,1 and C _1,1, (C) of Fig. 4 C _8,5 After the release of, the upper codes C _4,3 and C _2,2 can be used.

However, in the conventional resource management schemes, the OVSF code is managed using a binary tree data structure using the OVSF code format. If the resource management is done in the same tree structure as the OVSF code, the node will be deleted when the code is assigned, and the node will be added when the code is released. However, in the process of adding or deleting nodes, the nodes in the tree must be searched and the process of restoring the shape of the tree is added. Therefore, when the depth of the tree is large, a considerable processing time is required and a complicated algorithm is required. Debugging and modification will not be easy.

Alternatively, consider how to manage the code by storing the OVSF tree structure in a one-dimensional array. However, this algorithm is relatively simple, but it is difficult to guarantee real-time code allocation because it causes excessive execution procedure to search not only the use of allocation code but also the use of higher and lower codes in order to allocate one code. . In addition, in order to guarantee the orthogonality of the OVSF, the release process must go through a process of searching for use of all codes as well as the codes of the connected branches.

Therefore, the OVSF code allocation in the control station (RNC) 40 of the asynchronous radio access network (RAN) 20 through such a conventional resource allocation scheme not only does not perform real-time call processing, but also in a state where a large number of calls are connected. There was a problem that could cause excessive processing delays and errors during allocation and deallocation.

The present invention has been proposed in order to meet the above-described requirements. In order to implement efficient OVSF code allocation and release in a control station of an asynchronous mobile communication system (UTRAN), the storage structure of the OVSF code is configured in a one-dimensional array, Spreading code management method through double state management of planar tree structure that provides a complex method of real-time execution by eliminating complicated retrieval process during allocation and release through dual state management of code, and realizing spreading code allocation / deletion method using the same The object of the present invention is to provide a computer-readable recording medium having recorded thereon a program.

1 is an exemplary configuration diagram of a general wireless communication system.

2 is a diagram illustrating the structure and characteristics of an OVSF code tree used for channelization of downlink channels in a general asynchronous mobile communication system.

3 is an explanatory diagram showing a correct allocation method of OVSF codes in a general tree structure.

4 is an explanatory diagram showing a correct release method of an OVSF code having a general tree structure.

5 is a diagram illustrating an embodiment of a spreading code management method through dual state management of a planar tree structure according to the present invention;

6A and 6B are flow diagrams of one embodiment of a spreading code allocation and release method in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

10: mobile station (UE) 20: radio access network (RAN)

30: base station (Node-B) 40: control station (RNC)

50: Core Network (CN)

In order to achieve the above object, the present invention provides a method for managing a spreading code in a call processing processor in a wireless communication control station, in which a state is divided into two fields for each spreading code in order to satisfy an allocation rule of spreading codes. The first state field indicates whether the first state field is enabled, the second state field indicates whether it is available, and the resources of the spreading code tree are managed in a flat tree structure of a one-dimensional array to access lower spreading codes and higher spreading codes. It is characterized in that the index is directly accessed without going through the link information or retrieval process.

In order to achieve the above object, the present invention provides a spreading code allocation method in a call processing processor in a wireless communication control station, wherein when a spreading code allocation request is made, a spreading index (SF) is matched and a code index of 1 is calculated. A first step of making; A second step of determining whether the corresponding spreading code is in use or not based on the code index; And updating the state information of the corresponding spreading code to be allocated, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes according to the determination result of the second step. It is characterized by comprising a third step.

In addition, after performing the first step, within the range where the spreading coefficients SF coincide, the code index is sequentially increased to determine the state of the corresponding spreading code, and then the fourth step of performing the third step is further performed. Characterized in that the made up.

According to an aspect of the present invention, there is provided a spreading code release method in a call processing processor in a wireless communication control station, wherein the spreading code release request calculates a code index using a spreading factor (SF) and a code number. Stage 1; A second step of determining whether the corresponding spreading code is in use based on the code index; And updating the state information of the corresponding spreading code to be released, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes according to the determination result of the second step. It is characterized by comprising a third step.

In order to achieve the above object, the present invention provides a spreading code management apparatus including a processor, in which a state is divided into two fields for each spreading code in order to satisfy the spreading rule allocation rule. It indicates whether or not it is used, and whether it is available in the second status field, and manages the resources of the spreading code tree in a flat tree structure of a one-dimensional array, so that additional link information or retrieval process can be performed when accessing lower spreading codes and higher spreading codes. Provided is a computer readable recording medium having recorded thereon a program for realizing a function of directly accessing an array index without going through it.

The present invention for achieving the above object, for spreading code allocation, calculates a code index of which the spreading factor (SF) matches and the code number is 1 when spreading code allocation is requested to a wireless communication control station having a processor. A first function of doing; A second function of determining whether the corresponding spreading code is in use or not based on the code index; And updating the state information of the corresponding spreading code to be allocated, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes according to the determination result of the second function. A computer readable recording medium having recorded thereon a program for realizing the third function is provided.

In addition, according to the present invention, after performing the first function, the code index is sequentially increased within the range where the spreading coefficients (SF) coincide, and after determining the state of the corresponding spreading code, a fourth function of performing the third function is performed. A computer readable recording medium having recorded thereon a program for further realizing the function is provided.

In order to achieve the above object, the present invention provides a method for calculating a code index by using a spreading factor (SF) and a code number when a spreading code release request is made to a wireless communication control station having a processor for spreading code release. 1 function; A second function of determining whether a corresponding spreading code is used based on the code index; And updating the state information of the corresponding spreading code to be released upon updating the state information, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes according to the determination result of the second function. A computer readable recording medium having recorded thereon a program for realizing the third function is provided.

The call processing processor in the control station of the asynchronous mobile communication system manages the OVSF code used as the spreading code for channelization of the downlink channel during call setup and release. In the resource management module, a mechanism for allocating and releasing OVSF codes in real time is required in consideration of characteristics such as spreading coefficients and orthogonalities according to OVSF codes. Therefore, in the present invention, the OVSF code tree is stored as a one-dimensional array of a planar tree structure, and a double state field indicating whether or not to be used for each code is configured to remove a search procedure generated during the allocation and release process. Real-time resource management is induced by updating fields.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a diagram illustrating a spreading code management method through dual state management of a planar tree structure according to an embodiment of the present invention. FIG. 5 illustrates a resource storage structure and features. An example of mapping is shown below.

In the present invention, in order to satisfy the OVSF code allocation rule, the state is divided into two fields 5a and 5b for each code and dually managed.

Here, the first status field 5a indicates whether to use or not, and has one of "IDLE", "BUSY", and "QUASI-BUSY". At this time, "IDLE" means the status of available code, "BUSY" means the code currently in use, and "QUASI-BUSY" status cannot be used by lower codes connected to the same branch due to the use of higher codes. Indicates.

The second state field 5b is for managing availability, and stores the number of codes (BUSY-CHILD) of the current "BUSY" state among the lower codes of the corresponding code.

In addition, the present invention aligns the OVSF tree, which is a code resource, in a plane, that is, a one-dimensional array, to minimize processing time and facilitate management. That is, as shown in FIG. 5, the array is stored in order from the smallest spreading code and the smallest code number. In addition, each component code in the array can be directly accessed to the upper code and the lower code by using the code index, so that no search time is required and no additional link information is stored. Each component of the array is composed of a structure consisting of code status information, call information, and fields for storing code information.

6a and 6b show an OVSF code allocation and release method of the present invention, respectively.

First, referring to FIG. 6A, a method for allocating an OVSF code will be described with reference to FIG. 6A, in response to a code assignment request (601), when an OVSF code is allocated, a spreading factor (SF) previously inputted by a call processing processor of a control station (RNC). Using the call information, the index of the code array having the same spreading coefficient SF and the code number 1 is calculated (602), and the state of the corresponding code is determined based on the code index (603). That is, based on the code index, a valid code whose status is IDLE or not available (# BUSY-CHILD) is 0 is searched for status information update (603).

If the result of the search is not "IDLE" or the availability (# BUSY-CHILD) is not 0, the code index is increased by 1 (609) within the range where the diffusion coefficient (SF) matches (610). The state of the code is determined based on the index (603).

As a result of the search, if the use is "IDLE" and the availability (# BUSY-CHILD) is 0, the status information should be updated, and the data to be updated can be largely classified into three types. That is, the state information of the corresponding code to be allocated is updated (604), the state information of the lower codes is updated (605), and the state information of the higher codes is updated (606).

In detail, first, a state of using a corresponding code to be allocated is changed from a state of an available code (IDLE) to a state of a code currently being used (BUSY) (604). Then, the use status of the lower codes is changed from the available code status (IDLE) to the status (QUASI-BUSY) indicating that the lower codes connected in the same branch cannot be used due to the use of the upper code (605). As a result, the number of higher codes (BUSY-CHILD) is increased by one (606).

Thereafter, after the call information is stored in the code array (607), it is notified that the code allocation with the code number was successful (608).

Then, referring to FIG. 6B, referring to the OVSF code release method, in response to the code release request 621, when OVSF code is released, the spreading factor and the OVSF code number first inputted by the call processing processor of the control station RNC The index of the code array is calculated using the operation 622, and the state of the corresponding code is determined based on the code index (623). That is, based on the code index, it is checked whether the state of the corresponding code is the current code BUSY (623).

If the result of the check is that the state of the code is not " BUSY ", it indicates that the code release failed (624).

As a result of the check, if the status of the corresponding code is "BUSY", the status information should be updated, and the data to be updated can be classified into three types as in the code assignment process. That is, the state information of the corresponding code to be released is updated (625), the state information of the lower codes is updated (626), and the state information of the higher codes is updated (627).

In detail, first, the state of using the corresponding code to be released is changed from the state (BUSY) of the code currently being used to the state (IDLE) of the code available (625). Then, the state of using the lower codes is changed from the state (QUASI-BUSY) indicating that the same code connected to the same branch cannot be used due to the use of the upper code (QUASI-BUSY), and the available code state (IDLE) (626). As a result, the number of higher codes (BUSY-CHILD) is reduced by one (627).

Thereafter, after initializing the code array (628), it is notified that the code release was successful (629).

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention can perform a real-time call processing process and eliminate an error that may occur when allocating and releasing because the state search of related codes is not necessary when allocating and releasing through dual state management of OVSF codes. It has an effect.

In addition, the present invention introduces a planar tree structure that stores OVSF code trees in a one-dimensional array, which simplifies the processing, shortens the processing time, and facilitates expansion and modification in the program.

Claims (16)

A spreading code management method in a call processing processor in a wireless communication control station, In order to satisfy the law of allocation of spreading codes, each spreading code is divided into two fields for dual management. The first state field indicates whether it is used, the second state field indicates whether it can be used, A method for managing spreading codes by managing resources in a flat tree structure of a one-dimensional array so that when accessing lower spreading codes and higher spreading codes, the indexes of the arrays are directly accessed without additional link information or retrieval. The method of claim 1, The first status field includes a state indicating that IDLE of an available spreading code, BUSY of a spreading code currently being used, and lower spreading codes connected to the same branch due to use of a higher spreading code are not available. QUASI-BUSY) information, The second status field indicates spreading code number (# BUSY-CHILD) information of a current " BUSY " state among lower spreading codes of the corresponding spreading code, so as to guarantee orthogonality between the codes. Spreading code management method characterized in that to omit the search process. The method according to claim 1 or 2, The spreading code, Preferably, the spreading code management method, characterized in that the orthogonal variable spread coefficient (OVSF) code used for the channelization of the downlink channels. A spreading code allocation method in a call processing processor in a wireless communication control station, A first step of calculating a code index in which a spreading factor (SF) coincides with a code number of 0 when a spreading code allocation request is made; A second step of determining whether the corresponding spreading code is in use or not based on the code index; And In response to the determination result of the second step, updating the state information of the corresponding spreading code to be allocated, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes when updating the state information. 3 steps Spreading code allocation method comprising a. The method of claim 4, wherein After performing the first step, within the range where the diffusion coefficients (SF) coincide, the code index is sequentially increased to determine the state of the corresponding spreading code, and then the fourth step is performed. Spreading code allocation method further comprising. The method according to claim 4 or 5, The second step, Based on the code index, spreading code allocation for searching for a valid spreading code having a status of IDLE that can be used or not and availability of # BUSY-CHILD is 0 for updating status information Way. The method of claim 6, The third step, Changes the availability state of the corresponding spreading code to be allocated from the state of the available spreading code (IDLE) to the state of the spreading code currently being used (BUSY), and the state of the available spreading code in the state of the available spreading code ( IDLE) changes to the state (QUASI-BUSY) indicating that the same branched lower spreading code is unavailable due to the use of the higher spreading code, and increases the number of available spreading codes (BUSY-CHILD) by one. Spreading code allocation method, characterized in that. The method of claim 7, wherein The spreading code, Preferably, the spreading code allocation method, characterized in that the orthogonal variable spreading factor (OVSF) code used for channelization of the downlink channels. A spreading code release method in a call processing processor in a wireless communication control station, A first step of calculating a code index by using a spreading coefficient (SF) and a code number in the spreading code release request; A second step of determining whether the corresponding spreading code is in use based on the code index; And According to the determination result of the second step, when updating the state information, updating the state information of the corresponding spreading code to be released, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes. 3 steps Spreading code release method comprising a. The method of claim 9, The second step, Based on the code index, checking whether the state of the corresponding spreading code is a current code (BUSY). The method of claim 10, The third step, The state of using the corresponding spreading code to be released is changed from the state of the current spreading code (BUSY) to the state of available spreading code (IDLE), and the state of use of lower spreading codes is changed due to the use of the higher spreading code. Change from the state (QUASI-BUSY) indicating that the same spreading lower spreading code is unavailable (QUASI-BUSY) to the state of available spreading code (IDLE), which reduces the number of high spreading codes (BUSY-CHILD) by one. The spreading code release method, characterized in that. The method according to any one of claims 9 to 11, The spreading code, Preferably, the spreading code release method, characterized in that the orthogonal variable spread coefficient (OVSF) code used for channelization of the downlink channels. In a spreading code management device having a processor, In order to satisfy the law of allocation of spreading codes, each spreading code is divided into two fields for dual management. The first state field indicates whether it is used, the second state field indicates whether it can be used, Manages resources in a flat tree structure of one-dimensional array so that when accessing lower spreading codes and higher spreading codes, it directly accesses the array index without additional link information or retrieval process. A computer-readable recording medium having recorded thereon a program for realizing this. For spreading code assignment, to a wireless communication control station having a processor, A first function of calculating a code index in which a spreading factor (SF) coincides with a code number of 0 when a spreading code allocation request is made; A second function of determining whether the corresponding spreading code is in use or not based on the code index; And In response to the determination result of the second function, updating the state information of the corresponding spreading code to be allocated, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes when updating the state information. 3 functions A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 14, After performing the first function, within a range where the spreading coefficients (SF) coincide, the code index is sequentially increased to determine the state of the corresponding spreading code, and then the fourth function is performed. A computer-readable recording medium that records a program for further realization. In a wireless communication control station having a processor for spreading code release, A first function of calculating a code index by using a spreading coefficient (SF) and a code number in the spreading code release request; A second function of determining whether a corresponding spreading code is used based on the code index; And In response to the determination result of the second function, updating the state information of the corresponding spreading code to be released, updating the state information of the lower spreading codes, and then updating the state information of the higher spreading codes when the state information is updated. 3 functions A computer-readable recording medium having recorded thereon a program for realizing this.