KR100746412B1 - Multi-mode mobile communication terminal and method for reselecting cells of multi-mode mobile communication terminal using cell division code - Google Patents

Abstract

The present invention relates to a multi-mode mobile communication terminal and a cell reselection method of a multi-mode mobile communication terminal using a cell identification code. In particular, two or more different radio access methods using a cell identification code for cell reselection The present invention relates to a technique for effectively performing cell reselection between Access Technology (RAT).

A multi-mode mobile communication terminal according to the present invention comprises at least one RF transceiver for one or more specific radio access methods (RAT); At least one modulation and demodulation device for a particular RAT including a cell searcher and a finger; And a call quality comparison unit for performing call quality measurement and comparison between the RAT control unit for controlling the specific RAT RF transceiver and the specific RAT modulation and demodulation device and the RAT, the search result of the cell search unit, and the comparison result of the call quality comparison unit. And a multi-mode control device having a service selection unit for selecting a service accordingly.

Description

MULTI-MODE MOBILE COMMUNICATION TERMINAL AND METHOD FOR RESELECTING CELLS OF MULTI-MODE MOBILE COMMUNICATION TERMINAL USING CELL DIVISION CODE}

1 is a block diagram illustrating a multi-mode mobile communication terminal according to a preferred embodiment of the present invention.

2A and 2B are flowcharts illustrating a cell reselection method of a multi-mode mobile communication terminal using a cell identification code according to a preferred embodiment of the present invention.

3 is an exemplary diagram illustrating a cell reselection process between different RAT cells.

<Description of Symbols for Main Parts of Drawings>

10: RF transceiver

20: modulation and demodulation device

30: multi mode controller

40: cell search unit

50: finger portion

60: RAT control unit

70: call quality comparison unit

80 service selection unit

The present invention relates to a multi-mode mobile communication terminal and a cell reselection method of a multi-mode mobile communication terminal using a cell identification code. In particular, two or more different radio access methods using a cell identification code for cell reselection The present invention relates to a multi-mode mobile communication terminal and a cell reselection method for efficiently performing cell reselection between RATs.

The wireless mobile communication network basically supports a function (cell reselection) for moving between cells of the same radio access method (RAT) when the mobile communication terminal is operating in an idle mode. However, inter-RAT cell reselection of different RATs is not rapid.

For example, suppose that a WCDMA base station is partially installed and serviced above a synchronous CDMA base station currently installed nationwide. If a multi-mode mobile communication terminal supporting both WCDMA and synchronous CDMA is in and out of the WCDMA service area, the mobile communication terminal must switch quickly to receive CDMA service. However, when the mobile communication terminal cannot receive WCDMA service at all, it attempts to search for another service, which causes call reception and call origination failure. In addition, the existing beacon cells also help cell reselection only at different frequencies of the same service, and have not performed cell switching to other RATs.

In order to solve the above problems, the present invention provides a multi-mode mobile communication terminal and a multi-mode mobile terminal which effectively performs cell reselection between two or more different radio access methods (RATs) using a cell identification code for cell reselection. An object of the present invention is to provide a cell reselection method of a communication terminal.

A multi-mode mobile communication terminal according to the present invention comprises at least one RF transceiver for one or more specific radio access methods (RAT); At least one modulation and demodulation device for a particular RAT including a cell searcher and a finger; And a call quality comparison unit for performing call quality measurement and comparison between the RAT control unit for controlling the specific RAT RF transceiver and the specific RAT modulation and demodulation device and the RAT, the search result of the cell search unit, and the comparison result of the call quality comparison unit. And a multi-mode control device having a service selection unit for selecting a service accordingly.

In addition, the cell reselection method of the multi-mode mobile communication terminal using the cell identification code according to the present invention comprises the steps of: reading the stored priority RAT information and cell identification code information; First operating a RAT module designated as a RAT to search for a cell; Providing a RAT service if a suitable cell is detected through the search, and searching for a cell by operating all RAT modules when a suitable cell is not detected through the search; Performing a search and comparison operation between RATs when a suitable cell is found through the search by all the RAT modules; And providing a priority RAT service when the optimal cell is a priority RAT cell according to a result of the comparison operation, and providing a sub-RAT service when the optimal cell is not a priority RAT cell.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail.

1 is a block diagram illustrating a multi-mode mobile communication terminal according to a preferred embodiment of the present invention.

The multi-mode mobile communication terminal of FIG. 1 is composed of at least one RF transceiver 10 for a specific radio access method (RAT), at least one modulator / modulation device 20 for a specific RAT, and a multi-mode controller 30.

The at least one specific demodulation device 20 for a RAT includes a cell searching unit 40 for searching each RAT cell and a finger unit 50 for demodulating data. The cell searcher 40 may detect a first cell discrimination code for cell reselection between RATs and a second cell discrimination code for cell reselection of a specific RAT.

The cell discrimination code detection method of a cell using ISDMA or CDMA2000 standard CDMA as RAT is as follows.

First scan the corresponding CDMA frequency band.

As a result of the scan, the correlation value is calculated by changing the PN offset, which is a CDMA cell discrimination code, from 0 to 511 for a frequency having a high reception power. In this case, the Walsh code is 0, which is a value of a pilot channel.

If a PN offset having a high correlation is not found, a correlation value calculation process is performed for another frequency. If a PN offset having a high correlation is found, the PN offset becomes the cell identification code of the CDMA cell.

The cell discrimination code detection method of a cell using WCDMA as RAT is as follows.

First scan the corresponding CDMA frequency band.

An initial synchronization process is performed to find a cell identification code for a frequency having a high reception power.

First, slot synchronization is synchronized from a primary sync channel (P-SCH), and frame synchronization is synchronized from a secondary sync channel (S-SCH). In addition, a group of first scrambling codes may be known through a process of calculating correlation values with the S-SCH.

The first scrambling code is divided into 64 groups of 8 pieces each with 512 pieces. Since the group of the first scrambling codes can be known through the process of calculating the correlation with the S-SCH, a correlation value with the common pilot channel (CPICH) for the eight first scrambling codes in the group is obtained. The first scrambling code can be detected.

The multi-mode controller 30 includes a RAT control unit 60 for controlling a specific RAT RF transceiver 10 and a specific RAT modulation / demodulation device 20, and a call quality comparison unit for measuring and comparing call quality between RATs ( 70) and a service selector 80 for selecting a service according to a comparison result of the search result of the cell search unit 40 and the call quality comparison unit 70.

The call quality comparison unit 70 may compare call quality by measuring Ec / No (dB), which is the call quality of each RAT cell, and making an absolute comparison.

The service selector 80 provides a priority RAT service when the optimal cell is a priority RAT cell according to the comparison result of the call quality comparison unit 70, and provides a sub-RAT service when the priority cell is not a priority RAT cell.

2A and 2B are flowcharts illustrating a cell reselection method of a multi-mode mobile communication terminal using a cell identification code according to a preferred embodiment of the present invention.

Referring to FIGS. 2A and 2B, first, stored priority RAT information and cell discrimination code information for cell reselection are read (S100).

First, the cell is searched by operating the RAT module designated as RAT (S110).

The cell search method of a cell using ISDMA or CDMA2000 standard CDMA as RAT is as follows.

First scan the corresponding CDMA frequency band.

As a result of the scan, the correlation value is calculated by changing the PN offset, which is a CDMA cell discrimination code, from 0 to 511 for a frequency having a high reception power. At this time, the Walsh code is 0, which is a value of a pilot channel.

If a PN offset having a high correlation is not found, a correlation value calculation process is performed for another frequency. If a PN offset having a high correlation is found, the PN offset becomes the cell identification code of the CDMA cell.

After the cell identification code of the CDMA cell is found, the sync channel of Walsh code 32 and the paging channel of Walsh code 1 are demodulated.

The synchronization channel includes information about the base station itself, base station pilot transmission power, base station pilot PN phase offset, data transmission of the paging channel, and the like. With this information, the terminal can set the time of the system and determine the transmission power for transmitting the signal.

The call channel includes additional information provided to the terminal by the base station, call information for the specific terminal, channel allocation information, and the like.

The cell search method of a cell using WCDMA as RAT is as follows.

First scan the corresponding CDMA frequency band.

An initial synchronization process is performed to find a cell identification code for a frequency having a high reception power.

First, slot synchronization is synchronized from a primary sync channel (P-SCH), and frame synchronization is synchronized from a secondary sync channel (S-SCH). In addition, a group of first scrambling codes may be known through a process of calculating correlation values with the S-SCH.

The first scrambling code is divided into 64 groups of 8 pieces each with 512 pieces. Since the group of the first scrambling codes can be known through the process of calculating the correlation with the S-SCH, a correlation value with the common pilot channel (CPICH) for the eight first scrambling codes in the group is obtained. The first scrambling code can be detected.

After finding the cell identification code of the WCDMA cell, demodulate the primary common control physical channel (P-CCPCH) and the secondary common control physical channel (S-CCPCH) to provide system time, transmit power, call information, and channel allocation provided by the base station. Information and the like.

If a suitable cell is detected through the search, a first RAT service is provided (S120). If a suitable cell is not detected through the search, all RAT modules are operated to search for a cell (S130).

If a suitable cell is found through the search by all the RAT modules, the RAT call quality measurement and comparison are performed (S140).

Measurement and comparison of call quality between RATs can be performed by measuring Ec / No (dB) of each RAT cell and making an absolute comparison.

According to the result of the comparison operation, if the optimal cell is a priority RAT cell, a priority RAT service is provided, and if it is not a priority RAT cell, a sub-RAT service is provided (S150).

When a new cell signal is detected in the step of providing the priority RAT service, the cell identification code of the detected cell is checked (S160).

If the cell discrimination code is the first cell discrimination code for cell reselection between RATs, all RAT modules are operated to search for cells, and the service quality is measured and compared between RATs to determine a service (S130, S140, S150).

If the cell discrimination code is a second cell discrimination code for cell reselection of a specific RAT, a specific RAT module is operated to search for a cell, and a service quality is measured and compared between RATs to determine a service (S170, S140, S150).

If the cell identification code is not the first cell identification code or the second cell identification code, the existing priority RAT service is continuously provided (S120).

When a new cell signal is detected in the step of providing the sub RAT service, the cell identification code of the detected cell is checked (S180).

If the cell discrimination code is the first cell discrimination code for cell reselection between RATs, all RAT modules are operated to search for cells, and the service quality is measured and compared between RATs to determine a service (S130, S140, S150).

If the cell identification code is the second cell identification code for cell reselection of a specific RAT, a specific RAT module is operated to search for a cell, and call quality measurement and comparison between RATs are performed to determine a service (S170, S140). , S150).

If the cell discrimination code is not the first cell discrimination code or the second cell discrimination code, it is determined whether other RATs are available in cell information (S190). If there is a priority RAT, the priority RAT module is operated to search for a cell. Then, the service is determined by performing the call quality measurement and comparison operation between the RAT (S200, S140, S150).

3 is an exemplary diagram illustrating a cell reselection process between different RAT cells.

Here, first, the RAT is a WCDMA system, the (a) cell is a WCDMA cell, the (C) and (D) cells are synchronous CDMA cells, the (B) cell is a WCDMA beacon cell for cell reselection, (B) It is assumed that the cell uses the first cell identification code.

Referring to FIG. 3, when the mobile communication terminal is turned on in the area A, the mobile communication terminal first operates a WATDMA RAT module that is a RAT to search for a cell, and then performs a cell search to detect a signal of a cell, which is a WCDMA cell. Is detected and the RAT service state is first entered.

When the mobile communication terminal moves from area A to area B, the mobile communication terminal detects a signal of (B) cell, which is a WCDMA beacon cell for cell reselection, and checks the cell classification code of (B) cell to determine the first cell. As it is a delimiter code, all RAT modules are activated to search for cells.

When the RAT module of the synchronous CDMA system detects a signal of the (multi) cell, which is a synchronous CDMA cell, the call quality comparison unit of the multi-mode controller compares the call quality of the cell with the (a) cell and the ( The cell is selected as an optimal cell, thereby entering a sub-RAT service state.

If the mobile communication terminal is turned on in the region B, the mobile communication terminal moves from the region A to the region B as in the above case and selects the cell (C) as an optimal cell to be in the sub-RAT service state.

Subsequently, when the mobile communication terminal moves from the B area to the A area, the mobile communication terminal detects a signal of the (D) cell, which is a synchronous CDMA cell, and first of all, the service of the (A) cell, which is a RAT cell, from the cell information of the (D) cell. Check whether or not.

The mobile communication terminal first searches for a cell by operating a RAT module of a WCDMA system, which is a RAT, and detects a signal of a cell, which is a cell of a WCDMA system, through a cell search to enter a RAT service state.

The cell reselection method of the multi-mode mobile communication terminal using the multi-mode mobile communication terminal and the cell identification code according to the present invention has the following effects.

First, inter-RAT cell reselection between different RATs can be performed in the same manner as cell reselection in the same RAT.

Second, inter-RAT cell reselection between different RATs may be implemented by adding a first cell identification code or a second cell identification code for cell reselection to an existing beacon cell.

In addition, a preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, replacements and additions through the spirit and scope of the appended claims, such modifications and changes are the following claims It should be seen as belonging to a range.

Claims (6)

An RF transceiver for one or more specific radio access schemes (RATs); At least one modulation and demodulation device for a particular RAT including a cell searcher and a finger; And According to the RAT control unit for controlling the specific RAT RF transceiver and the RAT modulation and demodulation device and the call quality comparison unit for performing the call quality measurement and comparison between the RAT and the search results of the cell search unit and the comparison result of the call quality comparison unit Multi-mode controller having a service selector for selecting a service Multi-mode mobile communication terminal comprising a. The method of claim 1, The cell search unit detects a first cell discrimination code for cell reselection between RATs and a second cell discrimination code for cell reselection of a specific RAT. The method of claim 1, The service selection unit provides a priority RAT service when the optimal cell is a priority RAT cell according to a comparison result of the call quality comparison unit, and provides a sub-RAT service when the priority cell is not a priority RAT cell. Reading stored priority RAT information and cell identification code information; First operating a RAT module designated as a RAT to search for a cell; Providing a RAT service if a suitable cell is detected through the search, and searching for a cell by operating all RAT modules when a suitable cell is not detected through the search; Performing call-measurement and comparison between RATs when a suitable cell is found through searching by all the RAT modules; And Providing a priority RAT service if the optimal cell is a priority RAT cell according to a result of the comparison operation, and providing a sub-RAT service if the priority cell is not a priority RAT cell; Cell reselection method of a multi-mode mobile communication terminal using a cell identification code comprising a. The method of claim 4, wherein Checking a cell identification code of the detected cell when a new cell signal is detected in the providing of the priority RAT service; If the cell discrimination code is a first cell discrimination code for cell reselection between RATs, operating all RAT modules to search for cells, and determining a service by performing call quality measurement and comparison between RATs; If the cell discrimination code is a second cell discrimination code for cell reselection of a specific RAT, operating a specific RAT module to search for a cell, and determining a service by performing call quality measurement and comparison between RATs; And Continuing to provide an existing priority RAT service when the cell separation code is not the first cell identification code or the second cell identification code. Cell reselection method of a multi-mode mobile communication terminal using a cell identification code characterized in that it further comprises. The method of claim 4, wherein Checking a cell identification code of the detected cell when a new cell signal is detected in the providing of the sub RAT service; If the cell discrimination code is a first cell discrimination code for cell reselection between RATs, operating all RAT modules to search for cells, and determining a service by performing call quality measurement and comparison between RATs; If the cell discrimination code is a second cell discrimination code for cell reselection of a specific RAT, operating a specific RAT module to search for a cell, and determining a service by performing call quality measurement and comparison between RATs; And If the cell identification code is not the first cell identification code or the second cell identification code, it is determined whether other RATs are available in the cell information of the detected cell. Operation to search for cells and measure and compare call quality between RATs to determine service Cell reselection method of a multi-mode mobile communication terminal using a cell identification code characterized in that it further comprises.

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