JP2006074082A - Method of controlling radio measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect time difference of a system frame number to be provided to soft handover with a simple configuration by applying this apparatus to a radio measuring apparatus of a cell phone system of, for example, WCDMA with respect to the radio measuring apparatus. <P>SOLUTION: In this apparatus, the rough time difference of the system frame number is detected from a timing of receiving a system frame number concerning a presently receiving base station and a base station in a moving destination cell. After that, a phase difference of a frame is detected and corrected concerning the presently receiving base station and the base station in the moving destination. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of controlling a wireless measurement device, and can be applied to a wireless measurement device of a mobile phone system related to WCDMA (Wideband Code Division Multiple Access), for example. The present invention detects a rough time difference between the system frame numbers from the reception timing of the system frame numbers related to the base station currently receiving and the base station of the destination cell, and then detects the base station currently receiving and the destination cell. By detecting and correcting the phase difference of the frames related to the base station, it is possible to detect the time difference between the system frame numbers used for soft handover with a simple configuration.

  In recent years, in mobile phone systems such as WCDMA, when moving between cells, communication is ensured by soft handover.

  Here, as described in, for example, Japanese Patent Laid-Open No. 2003-179954, the soft handover is a system frame number (SFN) notified from the base station currently communicating and the base station of the destination cell. ) (SFN−SFN observed Time Differnce) is detected by the user terminal device, and this time difference is notified to the communicating base station, thereby establishing synchronization with the destination cell.

  For this reason, in a user terminal based on WCDMA, the system frame number can be detected simultaneously by the hardware configuration of both the base station currently communicating and the base station of the destination cell.

  On the other hand, in such a mobile phone system, a radio communication wave transmitted from a base station is received by a radio measurement device, and the reception result is evaluated, so that maintenance of the equipment is performed.

In such a wireless measurement device, there is a case where measurement is continued by moving a cell. Therefore, it is desired that such a wireless measurement device also secures communication by soft handover when moving between cells. . As a matter of course, a simple configuration is desired for such soft handover.
Japanese Patent Laid-Open No. 2003-179954

  The present invention has been made in consideration of the above points, and an object of the present invention is to propose a control method for a radio measurement apparatus capable of detecting a time difference between system frame numbers used for soft handover with a simple configuration.

  In order to solve this problem, the invention of claim 1 is applied to a control method of a radio measurement apparatus according to a code division multiple access radio communication system, and receives a system frame number reception timing of a currently receiving base station. And the reception timing of the system frame number related to the base station of the destination cell, and based on the detection result, the system frame number related to the currently receiving base station and the base of the destination cell Detecting a rough time difference with a system frame number related to the station, detecting a phase difference between the frame related to the currently receiving base station and the frame related to the base station of the destination cell, and based on the detection result, Correcting a rough time difference, the system frame number related to the currently receiving base station and the system frame number related to the base station of the destination cell To detect the difference.

  The configuration of claim 1 is applied to a control method of a radio measurement apparatus according to a radio communication system of code division multiple access, and the reception timing of a system frame number related to a currently receiving base station and the base of a destination cell Sequentially detecting the reception timing of the system frame number related to the station, and based on the detection result, the system frame number related to the currently receiving base station, and the system frame number related to the base station of the destination cell, In the case of detecting a rough time difference, it is possible to detect the rough time difference by sequentially switching the operation of one system of the receiving mechanism. Further, even when detecting a phase difference between the frame related to the currently receiving base station and the frame related to the base station of the target cell, it is detected by processing the received data obtained by a single reception mechanism. can do. Accordingly, the rough time difference is corrected based on the detection result thus obtained, and the time difference between the system frame number related to the currently receiving base station and the system frame number related to the base station of the destination cell is calculated. If detected, it is possible to detect a time difference between system frame numbers used for soft handover with a simple hardware configuration.

  According to the present invention, it is possible to detect a time difference between system frame numbers used for soft handover with a simple configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 1 is a block diagram illustrating a wireless measurement device according to an embodiment of the present invention. The wireless measurement device 1 receives a wireless communication wave transmitted from a base station and performs various measurements for evaluation of reception results for a mobile phone system using WCDMA.

  That is, in the wireless measuring device 1, the display unit 2 displays various measurement results under the control of the system control unit 3. The RF unit 5 amplifies a radio communication wave obtained from the antenna 5 under the control of the system control unit 3, performs baseband conversion, and outputs the amplified signal. An analog-digital conversion circuit (AD) 6 performs analog-digital conversion processing on the baseband output of the RF unit 4 and outputs received data.

  The baseband processing unit 8 processes the reception data output from the analog-digital conversion circuit 6 under the control of the system control unit 3, thereby outputting various data necessary for processing in the wireless measurement device 1. That is, in the baseband processing unit 8, the search processing unit 8A performs a cell search process under the control of the system control unit 3, and detects a sync frame number, a chip offset, a scrambling code, and the like. The data demodulator 8B detects various data transmitted from the base station by processing the received data using the scrambling code detected by the search processor 8A. In addition to the search processing unit 8A and the data demodulating unit 8B, the baseband processing unit 8 is provided with various processing units related to the measurement function of the wireless measurement device 1, and for example, RSCP is performed by processing by these various processing units. (Received Signal Code Power) etc. can be detected.

  The system control unit 3 is constituted by arithmetic processing means, and controls the operation of the wireless measuring device 1 by executing a predetermined processing program in response to the operation of the operator by the user. In this control, when the system control unit 3 moves to an adjacent cell, the system frame number time difference notified from the currently communicating base station and the base station of the destination cell by executing the processing procedure shown in FIG. And the time difference is notified to the communicating base station, thereby executing a series of processes by soft handover.

  That is, when starting this processing procedure, the system control unit 3 moves from step SP1 to step SP2, and for the base station currently communicating, the time stamp Chip # Off # a at the time of receiving the system frame number SFN # ai and the BCH frame Is detected. Here, in this case, the system control unit 3 uses a so-called three-step cell search method established by 3GPP (3rd Generation Partnership Project) under the control of the search processing unit 8A to establish a dedicated channel (DPCH) with a base station that is currently communicating. : Dedicated Physical Channel) is detected, and the system frame number SFN # ai for the currently communicating base station is detected by detecting the system frame number corresponding to the connection frame number of this dedicated channel. Further, the chip offset Chip # Off # a is detected by detecting the BCH frame reception time by the frame of the system frame number SFN # ai and the measurement baseband clock by the chip.

  Subsequently, the system control unit 3 moves to step SP3, detects the system frame number SFN # bi related to the handover in the same manner as in step SP2 for the base station of the destination cell under the control of the search processing unit 8A, A chip offset Chip # Off # b is detected by detecting the BCH frame reception time by the measurement baseband clock by the chip.

  Here, the difference value Chip # Off # b−Chip # Off # a of the chip offset Chip # Off # a and Chip # Off # b detected in this way is set as ΔChip # diff, and this difference value ΔChip # diff is set to 1. When the integer and the remainder divided by the number of chips of the frame 38400 are set as ΔSFN and ΔCHIPS, respectively, the time difference Time # Diff between the system frame numbers notified from the currently communicating base station and the base station of the movement destination cell is calculated in step SP2. Assuming that there is no change in the time reference used for detecting the chip offset in SP3, it can be expressed by the following equation. Here, 256 is the number of system frame numbers in one cycle.

  However, in practice, in the measurement at steps SP2 and SP3, fluctuations in delay time, software operation time, etc. in the RF unit 4 also occur, so the time difference Time # Diff according to the equation (1) includes an error. Will be.

  As a result, the system control unit 3 proceeds to step SP4, instructs the search processing unit 8A to perform unspecified base station measurement, and detects the chip offset value between the base station in communication and the base station of the destination cell. To do. Here, the unspecified base station measurement is a process of detecting scrambling codes and the like related to all receivable base stations. In this embodiment, the so-called CPICH search method that directly detects CPICH (Common Point Channel). The reception data obtained from the analog-digital conversion circuit 6 is recorded and held in a memory, and the phase of all scrambling codes allocatable to the base station is sequentially changed with respect to the reception data recorded and held in the memory. By detecting the correlation value, the currently received base station scrambling code is detected.

  In this series of processing, the system control unit 3 detects the phase at which the correlation value rises by sequentially changing the phase of the scrambling code for the base station in communication and the base station of the movement destination cell. Based on this detection result, the inter-frame phase difference between these two base stations is detected by the chip offset value ΔChips # Scan # bit.

  Thereby, in step SP4, the system control unit 3 performs the difference between the sync frame numbers detected by the sync frame numbers SFN # ai, SFN # bi, chip offset Chip # Off # a, and Chip # Off # b detected in steps SP2 and SP3. Using ΔSFN and the chip offset value ΔChips # Scan # bit detected in step SP4, the calculation processing of the following equation is executed, and this is notified from the base station currently communicating and the base station of the destination cell Find the frame number time difference Time # Diff.

  As a result, the system control unit 3 detects the system frame number time difference Time # Diff roughly by individually detecting the reception timing of the system frame number for the currently communicating base station and the base station of the destination cell. Thereafter, correction is made by the phase difference between the frames related to the system frame number detected by the unspecified base station measurement, thereby providing a system frame for soft handover with a simple configuration by a processing system of one system of received data. The time difference between numbers can be detected.

  Accordingly, the system control unit 3 notifies the time difference Time # Diff of the system frame numbers detected in this way to the currently communicating base station, and then proceeds to step SP6 to end this processing procedure. .

(2) Operation of Embodiment In the above-described configuration, in this wireless measuring device 1, after the wireless communication wave obtained via the antenna 5 is processed by the RF unit 4, it is converted into received data by the analog-digital conversion circuit 6. The received data is processed by the baseband processing unit 8 to detect various measurement data. In the wireless measurement device 1, the measurement data is displayed on the display unit 2, thereby providing information necessary for maintenance of the base station related to the measurement location.

  In the wireless measuring device 1, various measurement processes are performed while moving the measurement point. When the cell is moved by such a movement, the base station that has been received up to that point by the soft handover is used. The communication with the station is switched to the communication with the base station of the destination cell.

  Prior to this soft handover, in the radio measurement apparatus 1, the search processing unit 8A detects the system frame number and chip offset associated with the current base station, thereby receiving the system frame number associated with this base station. Timing is detected. Further, by switching the operation of the search processing unit 8A, the system frame number and the chip offset are detected for the base station of the destination cell, thereby detecting the reception timing of the system frame number related to the base station of the destination cell. Is done.

  In the wireless measuring device 1, the time difference between the system frame numbers between these base stations is roughly detected based on the system frame numbers and chip offsets related to the two base stations detected at these different times. However, the time difference detected in this way includes an error.

  As a result, in the wireless measuring device 1, the phase difference between the frames related to these two base stations is detected by the unspecified base station measurement in the search processing unit 8A, and the system frame number roughly detected by the phase difference between these frames is detected. The time difference is corrected and the time difference of the correct system frame number is detected.

  Thus, in the detection of such a rough time difference between the system frame numbers, the operation of the single hit processing unit 8A can be sequentially switched and executed, whereas the phase difference between frames is also detected by one search. It can be executed by processing the received data by the processing unit 8A.

  As a result, in this wireless measuring device 1, it is possible to configure the system with one system of receiving mechanism and detect the time difference between the system frame numbers, and to that extent, the system frame number used for soft handover with a simple hardware configuration. It is designed to be able to detect the time difference.

  In the case where the operation of the receiving mechanism is sequentially switched and the time difference between the system frame numbers is detected step by step, it is assumed that the wireless measurement device 1 does not move greatly during these processes. However, in a normal user terminal device applied to this type of system, there may be a large movement during such a series of processes due to, for example, movement of a vehicle or the like. It becomes difficult. However, in this type of wireless measuring apparatus 1, even if the time difference between the system frame numbers is detected stepwise in this manner by moving while performing various measurement processes by the operation of the operator, it is practically sufficient. Can be used practically. As a result, in this embodiment, the hardware configuration is simplified to reduce power consumption, and resources can be used effectively.

(3) Effects of the embodiment According to the above configuration, after detecting a rough time difference between the system frame numbers from the reception timing of the system frame numbers related to the currently receiving base station and the base station of the destination cell, By detecting and correcting the phase difference between the base station currently receiving and the base station of the destination cell, it is possible to detect the time difference between the system frame numbers used for soft handover with a simple configuration.

  In the above-described embodiment, the reception timing of the system frame number is detected in the order of the base station currently receiving and the base station of the destination cell, and then the base station of the base station currently receiving and the destination cell base Although the case where the phase difference of the frame related to the station is detected has been described, the present invention is not limited to this, and the detection order can be variously changed as necessary.

  In the above-described embodiments, the case where the present invention is applied to the wireless measurement device of the mobile phone system related to wide area code division multiple access has been described. However, the present invention is not limited to this, and the present invention relates to normal code division multiple access. The present invention can be widely applied to wireless measuring devices for mobile phone systems.

  The present invention can be applied to a wireless measurement device of a cellular phone system related to wide area code division multiple access.

It is a block diagram which shows the wireless measuring device which concerns on the Example of this invention. It is a flowchart which shows the process sequence of the system control part in the wireless measuring device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wireless measuring device, 3 ... System control part, 8 ... Baseband processing part, 8A ... Search processing part, 8B ... Data demodulation part

Claims (1)

A control method of a radio measurement apparatus according to a code division multiple access radio communication system,
The reception timing of the system frame number related to the currently receiving base station and the reception timing of the system frame number related to the base station of the target cell are sequentially detected, and based on the detection result, Detecting a rough time difference between a system frame number related to a base station and a system frame number related to a base station of the destination cell;
Detecting a phase difference between the frame related to the currently received base station and the frame related to the base station of the target cell, correcting the rough time difference based on the detection result, and then receiving the currently received base station A method for controlling a radio measurement apparatus, comprising: detecting a time difference between a system frame number related to a base station and a system frame number related to a base station of the destination cell.

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