JP2005005919A

JP2005005919A - Mobile telephone unit and peripheral cell searching method used therefor

Info

Publication number: JP2005005919A
Application number: JP2003165841A
Authority: JP
Inventors: Osamu Hasegawa; 修長谷川
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2003-06-11
Filing date: 2003-06-11
Publication date: 2005-01-06
Anticipated expiration: 2023-06-11
Also published as: JP4218430B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile telephone device which is capable of dispensing with unnecessary cell searches so as to reduce current consumption. <P>SOLUTION: Receiving signals inputted through an antenna 11 are outputted to a cell searching circuit 12 and a quality measurement circuit 13. The cell searching circuit 12 detects cells on the basis of the receiving signals inputted through the antenna 11, and outputs the detected cells to the quality measurement circuit 13. The quality measurement circuit 13 measures the quality of the cells detected by the cell searching circuit 12, and outputs the measurement result to a peripheral cell counting circuit 14. The peripheral cell counting circuit 14 calculates the number of undetected cells existing around on the basis of the qualities of waiting cells and monitor cells detected by the quality measurement circuit 13, and the number of the undetected cells is outputted to the cell searching circuit 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は携帯電話装置及びそれに用いる周辺セルサーチ方法に関し、特にＩＭＴ−２０００（ＩｎｔｅｒｎａｔｉｏｎａｌＭｏｂｉｌｅＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ−２０００）方式の携帯電話装置において待ち受け時に行う周辺セルサーチに関する。
【０００２】
【従来の技術】
従来、この種の携帯電話装置においては、通信待ち受け時における間欠受信モードで、下りリンクにおいて最も受信電力（逆拡散後の相関ピーク電力）の大きな共通パイロットチャネル（ＣＰＩＣＨ：ＣｏｍｍｏｎＰｉｌｏｔＣｈａｎｎｅｌ）のスクランブルコードを有するセルを検出するセルサーチが行われている。
【０００３】
すなわち、この携帯電話装置では、通信待ち受け時において、一定時間毎に最大受信レベルの共通パイロットチャネルを有するセルを検出するセルサーチと、このセルからのページングチャネル（ＰＣＨ：ＰａｇｉｎｇＣｈａｎｎｅｌ）の受信を間欠的に行う。
【０００４】
これによって、携帯電話装置では、サーチすべき周辺セルのスクランブルコードの種類及び自装置における共通パイロットチャネルの平均的な受信タイミングが既知となるので、短時間での周辺セルサーチが可能となる（例えば、非特許文献１参照）。
【０００５】
上記の携帯電話装置において周辺セルサーチを行う回路部分を図３に示す。図３において、携帯電話装置２はアンテナ２１と、セルサーチ回路２２と、品質測定回路２３とを備えている。
【０００６】
アンテナ２１より受信される受信信号はセルサーチ回路２２で信号解析され、待ち受けセル（ＳｅｒｖｉｎｇＣｅｌｌ）とモニタセル（ＭｏｎｉｔｏｒＣｅｌｌ）とが決定される。それら待ち受けセル及びモニタセルの情報は品質測定回路２３に通達され、品質測定回路２３で待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏが測定される。
【０００７】
【非特許文献１】
「Ｗ−ＣＤＭＡ移動通信方式２無線伝送方式２−２Ｗ−ＣＤＭＡ基本伝送技術２−２−２セルサーチ」（立川敬二監修、丸善株式会社刊、平成１３年６月２５日発行、第３５−４５頁）
【０００８】
【発明が解決しようとする課題】
上述した従来の携帯電話装置では、待ち受け時に行う周辺セルサーチを、待ち受けセルの品質に依らず、常に周辺にセルがないかのサーチを実施するか、もしくは待ち受けセルの品質がある一定以上の場合に全く周辺をサーチしない。
【０００９】
逆に、従来の携帯電話装置では、待ち受けセルの品質がある一定以下だと、常に周辺にセルがないかのサーチを実施しているため、存在しうるセルをモニタセルとして全て検出済みであっても、不要なサーチを実施して消費電流を増大させることとなる。
【００１０】
そこで、本発明の目的は上記の問題点を解消し、不要なセルサーチを省略することができ、消費電流を低減することができる携帯電話装置及びそれに用いる周辺セルサーチ方法を提供することにある。
【００１１】
【課題を解決するための手段】
本発明による携帯電話装置は、待ち受け時に所定周期で周辺セルサーチを行う携帯電話装置であって、前記待ち受け時に待ち受けセルとモニタセルとの品質に応じて未検出セル数を予想する手段と、その予想したセル数だけ前記周辺セルサーチを行う手段とを備えている。
【００１２】
本発明による他の携帯電話装置は、セルを検出するためのセルサーチ回路と、前記セルサーチ回路で検出されたセルの品質を測定する品質測定回路と、前記品質測定回路で測定された待ち受けセルとモニタセルとの品質結果を基に周辺に存在しうる未検出のセル数を算出する周辺セル数算出回路とを備え、前記周辺セル数算出回路で算出された前記未検出のセル数だけ前記セルサーチ回路でセルサーチを行っている。
【００１３】
本発明による周辺セルサーチ方法は、待ち受け時に所定周期で周辺セルサーチを行う携帯電話装置の周辺セルサーチ方法であって、前記携帯電話装置側で、前記待ち受け時に待ち受けセルとモニタセルとの品質に応じて未検出セル数を予想し、その予想したセル数だけ前記周辺セルサーチを行っている。
【００１４】
本発明による他の周辺セルサーチ方法は、セルサーチ回路で検出されたセルの品質を品質測定回路で測定し、その測定された待ち受けセルとモニタセルとの品質結果を基に周辺に存在しうる未検出のセル数を周辺セル数算出回路で算出し、前記周辺セル数算出回路で算出された前記未検出のセル数だけ前記セルサーチ回路でセルサーチを行っている。
【００１５】
すなわち、本発明の周辺セルサーチ方法は、ＩＭＴ−２０００（ＩｎｔｅｒｎａｔｉｏｎａｌＭｏｂｉｌｅＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ−２０００）方式の携帯電話装置において、特に待ち受け時に待ち受けセル（ＳｅｒｖｉｎｇＣｅｌｌ）とモニタセル（ＭｏｎｉｔｏｒＣｅｌｌ）との品質Ｅｃ／Ｎｏに応じて未検出セル数を予想し、予想したセル数だけをサーチすることで、不要なセルサーチを省略し、消費電流を削減することを特徴とする。
【００１６】
より具体的に説明すると、本発明の周辺セルサーチ方法では、セルを検出するためのセルサーチ回路と、検出できたセルの品質を測定する品質測定回路と、測定された品質を基に周辺セル数を算出する周辺セル数算出回路とを携帯電話装置に具備し、品質測定回路で測定された待ち受けセルとモニタセルとの品質結果を基に周辺セル数算出回路が周辺に存在しうる未検出のセル数を算出し、その未検出のセル数をセルサーチ回路へ与えることで、存在する可能性のあるセル数だけをサーチしている。
【００１７】
これによって、本発明の周辺セルサーチ方法では、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏを測定し、その測定された品質Ｅｃ／Ｎｏを総和することで、周辺に存在しうるセル数を予め算出することが可能となるので、存在しうるセル数以上のセルサーチを行わなくて済むため、不要なセルサーチを省略することが可能となり、消費電流を低減することが可能となる。
【００１８】
【発明の実施の形態】
次に、本発明の実施例について図面を参照して説明する。図１は本発明の一実施例による携帯電話装置における周辺セルサーチを行う回路部分の構成を示すブロック図である。図１において、携帯電話装置１はＩＭＴ−２０００（ＩｎｔｅｒｎａｔｉｏｎａｌＭｏｂｉｌｅＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ−２０００）方式の携帯電話装置であり、アンテナ１１と、セルサーチ回路１２と、品質測定回路１３と、周辺セル数算出回路１４とから構成されている。
【００１９】
アンテナ１１は入力される受信信号をセルサーチ回路１２と品質測定回路１３とにそれぞれ出力する。セルサーチ回路１２はアンテナ１１からの受信信号を基にセルを検出し、検出したセルを品質測定回路２に出力する。
【００２０】
品質測定回路１３はセルサーチ回路１２で検出されたセルの品質を測定し、その測定結果を周辺セル数算出回路１４に出力する。周辺セル数算出回路１４は品質測定回路１３で測定された待ち受けセルとモニタセルとの品質結果を基に、周辺に存在しうる未検出のセル数を算出し、その未検出のセル数をセルサーチ回路１２に出力する。
【００２１】
図２は図１の携帯電話装置１の動作を示すフローチャートである。これら図１及び図２を参照して携帯電話装置１の動作について説明する。
【００２２】
アンテナ１１で受信された受信信号はセルサーチ回路１２で信号解析され、待ち受けセル（ＳｅｒｖｉｎｇＣｅｌｌ）とモニタセル（ＭｏｎｉｔｏｒＣｅｌｌ）とが決定される。その待ち受けセル及びモニタセルの情報は品質測定回路１３に通達され、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏが測定される。
【００２３】
待ち受けセルとモニタセルとの品質情報は周辺セル数算出回路１４に入力され、周辺セル数算出回路１４で周辺に存在しうる未検出なセル数が算出され、算出結果がセルサーチ回路１２に通達される。セルサーチ回路１２は周辺セル数算出回路１４から通達される未検出セル数がある場合に、未検出セル数分だけ検出するようにサーチ動作を繰り返す。
【００２４】
例えば、品質測定回路１４では、図２に示すように、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏを測定する。図２には、測定結果として、
＜Ｅｘａｍｐｌｅ１＞
ＳｈｅｒｖｉｎｇＣｅｌｌ：Ｅｃ／Ｎｏ＝３ｄＢ
＜Ｅｘａｍｐｌｅ２＞
ＳｈｅｒｖｉｎｇＣｅｌｌ：Ｅｃ／Ｎｏ＝６ｄＢ
ＭｏｎｉｔｏｒＣｅｌｌ：Ｅｃ／Ｎｏ＝６ｄＢ
＜Ｅｘａｍｐｌｅ３＞
ＳｈｅｒｖｉｎｇＣｅｌｌ：Ｅｃ／Ｎｏ＝６ｄＢ
ＭｏｎｉｔｏｒＣｅｌｌ：Ｅｃ／Ｎｏ＝１２ｄＢ
の３つの例を図示している。
【００２５】
図２を参照して周辺セル数算出回路１４の動作について説明する。ＩＭＴ−２０００方式で、常時、図示せぬ基地局から送信されているＰ−ＣＰＩＣＨ（ＰｒｉｍａｒｙＣｏｍｍｏｎＰｉｌｏｔＣｈａｎｎｅｌ）とＰ−ＣＣＰＣＨ（ＰｒｉｍａｒｙＣｏｍｍｏｎＣｏｎｔｒｏｌＰｈｙｓｉｃａｌＣｈａｎｎｅｌ）を、例えば、Ｐ−ＣＰＩＣＨ／Ｐ−ＣＣＰＣＨ＝０ｄＢとしている場合について説明する。
【００２６】
品質の測定は、一般的に、Ｐ−ＣＰＩＣＨのＥｃ／Ｎｏ［＝ＲＳＣＰ（ＲｅｃｅｉｖｅｄＳｉｇｎａｌＣｏｄｅＰｏｗｅｒ）−ＲＳＳＩ（ＲｅｃｅｉｖｅＳｉｇｎａｌＳｔｒｅｎｇｔｈＩｎｄｉｃａｔｉｏｎ）］を測定して求められる。
【００２７】
したがって、１セル理想環境では、Ｐ−ＣＰＩＣＨ／ＰＣＣＰＣＨ＝０ｄＢであることから、品質Ｅｃ／Ｎｏが−３ｄＢとなる（図２ステップＳ１）。よって、例えば、待ち受けセルの品質Ｅｃ／Ｎｏが−３ｄＢの場合には周辺にセルが存在しないので（図２ステップＳ２）、未検出セルのサーチを実施しない（図２ステップＳ４）。
【００２８】
また、待ち受けセルの品質Ｅｃ／Ｎｏが−６ｄＢの場合には、周辺にセルが少なくとも１セルは存在する可能性があるので（図２ステップＳ２）、モニタしているセルがなければ、未検出セルが少なくとも１セルあるとして１セル分サーチを実施する（図２ステップＳ３）。
【００２９】
モニタしているセルが１セルある場合には、モニタセルの品質Ｅｃ／Ｎｏが−６ｄＢであれば、他のセルが存在しないので、未検出セルをサーチしない。また、モニタセルの品質Ｅｃ／Ｎｏが−６ｄＢ未満の場合には、他のセルが１セル存在する可能性があるので、未検出セルが少なくとも１セルあるとして、１セル分サーチを実施する。
【００３０】
上述したように、本実施例では、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏの総和から存在しうるセル数を算出することが可能となり、未検出セルが存在する可能性がある場合のみセルサーチ回路１２が周辺セル数算出回路１４から指示され、サーチ動作を実施する。
【００３１】
このように、本実施例では、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏを測定し、その測定された品質Ｅｃ／Ｎｏを総和することで、周辺に存在しうるセル数を予め算出することができ、存在しうるセル数以上のセルサーチを行わなくて済むため、不要なセルサーチを省略することができ、消費電流を低減することができる。
【００３２】
尚、本発明では、オペレータによってＰ−ＣＰＩＣＨとＰ−ＣＣＰＣＨとのパワー比が違う場合もあるので、携帯電話装置１内部に、測定された品質Ｅｃ／Ｎｏの総和と算出された周辺に存在しうるセル数との関係を学習する学習機能を持たせることで、周辺に存在しうるセル数をより精度が高く予見することができる。
【００３３】
また、本発明では、待ち受けセルとモニタセルとの品質Ｅｃ／Ｎｏの総和によって、品質の悪い、例えば品質Ｅｃ／Ｎｏ＝−１５ｄＢ未満の未検出セルが存在しうることを算出することができた場合に、品質の悪いセルを検出しても有益ではないため、予めある閾値以下の未検出セルの存在を算出することができてもサーチを実施しないとすることも可能である。これによって、不要なサーチを削減することができ、消費電流の低減を実現することができる。
【００３４】
さらに、本発明では、上記の周辺セルサーチ方法を通信中にも利用することが可能である。携帯電話装置１においては通信中、常にセルサーチを行っているので、消費電流削減の効果はないが、不要なサーチを省略することでアクティブセル（ＡｃｔｉｖｅＣｅｌｌ）やモニタセルのサーチ周期を早めることが可能となり、より精度の高いサーチと平均化とが可能となる。
【００３５】
例えば、Ａｃｔｉｖｅ１、Ａｃｔｉｖｅ２、及びＭｏｎｉｔｏｒ１が見えており、それぞれのセルの品質Ｅｃ／Ｎｏの和が存在しうるセルの値と等しくなる場合には、未検出な周辺セルが存在しないことになる。したがって、この場合には毎回、Ａｃｔｉｖｅ１、Ａｃｔｉｖｅ２、及びＭｏｎｉｔｏｒ１だけを周期監視していれば良いことになる。
【００３６】
【発明の効果】
以上説明したように本発明は、上述したような構成及び動作とすることで、不要なセルサーチを省略することができ、消費電流を低減することができるという効果が得られる。
【図面の簡単な説明】
【図１】本発明の一実施例による携帯電話装置における周辺セルサーチを行う回路部分の構成を示すブロック図である。
【図２】図１の携帯電話装置の動作を示すフローチャートである。
【図３】従来例による携帯電話装置における周辺セルサーチを行う回路部分の構成を示すブロック図である。
【符号の説明】
１携帯電話装置
１１アンテナ
１２セルサーチ回路
１３品質測定回路
１４周辺セル数算出回路[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile phone device and a peripheral cell search method used for the mobile phone device, and more particularly to a peripheral cell search performed at the time of standby in an IMT-2000 (International Mobile Telecommunications-2000) mobile phone device.
[0002]
[Prior art]
Conventionally, in this type of mobile phone device, a scramble code of a common pilot channel (CPICH: Common Pilot Channel) having the largest reception power (correlation peak power after despreading) in the downlink in the intermittent reception mode when waiting for communication A cell search is performed to detect cells having
[0003]
That is, in this mobile phone device, when waiting for communication, a cell search for detecting a cell having a common pilot channel with a maximum reception level every certain time and a reception of a paging channel (PCH) from this cell are intermittent. Do it.
[0004]
As a result, since the mobile phone device knows the type of the scramble code of the neighboring cell to be searched and the average reception timing of the common pilot channel in the own device, the neighboring cell search can be performed in a short time (for example, Non-Patent Document 1).
[0005]
FIG. 3 shows a circuit portion for performing a peripheral cell search in the above mobile phone device. In FIG. 3, the mobile phone device 2 includes an antenna 21, a cell search circuit 22, and a quality measurement circuit 23.
[0006]
The received signal received from the antenna 21 is subjected to signal analysis by the cell search circuit 22, and a standby cell (Serving Cell) and a monitor cell (Monitor Cell) are determined. Information on these standby cells and monitor cells is sent to the quality measurement circuit 23, and the quality measurement circuit 23 measures the quality Ec / No between the standby cells and the monitor cells.
[0007]
[Non-Patent Document 1]
"W-CDMA mobile communication system 2-wireless transmission system 2-2W-CDMA basic transmission technology 2-2-2 cell search" (supervised by Keiji Tachikawa, published by Maruzen Co., Ltd., June 25, 2001, No. 35-45) page)
[0008]
[Problems to be solved by the invention]
In the above-described conventional mobile phone device, the peripheral cell search performed at the time of standby is always performed as to whether there is a cell in the vicinity regardless of the quality of the standby cell, or the quality of the standby cell is a certain level or higher. Does not search the neighborhood at all.
[0009]
On the other hand, in the conventional mobile phone device, if the quality of the standby cell is below a certain level, a search is always performed for cells in the vicinity, so all the cells that can exist are detected as monitor cells. However, an unnecessary search is performed to increase current consumption.
[0010]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a mobile phone device that can eliminate the above-described problems, omit unnecessary cell search, and reduce current consumption, and a peripheral cell search method used therefor. .
[0011]
[Means for Solving the Problems]
The mobile phone device according to the present invention is a mobile phone device that performs a peripheral cell search at a predetermined period when waiting, and means for predicting the number of undetected cells according to the quality of the standby cell and the monitor cell at the standby time, and its prediction Means for performing the neighboring cell search by the number of cells obtained.
[0012]
Another cell phone device according to the present invention includes a cell search circuit for detecting a cell, a quality measurement circuit for measuring the quality of the cell detected by the cell search circuit, and a standby cell measured by the quality measurement circuit. And a peripheral cell number calculation circuit that calculates the number of undetected cells that can exist in the vicinity based on the quality results of the monitor cell and the number of undetected cells calculated by the peripheral cell number calculation circuit A cell search is performed by the search circuit.
[0013]
A neighbor cell search method according to the present invention is a neighbor cell search method for a mobile phone device that performs a neighbor cell search at a predetermined period when waiting, and the mobile phone device according to the quality of the stand-by cell and the monitor cell at the stand-by time Thus, the number of undetected cells is predicted, and the neighboring cell search is performed for the estimated number of cells.
[0014]
According to another peripheral cell search method of the present invention, the quality of a cell detected by the cell search circuit is measured by a quality measurement circuit, and the quality of the measured standby cell and monitor cell can be present in the vicinity. The number of detected cells is calculated by a peripheral cell number calculating circuit, and cell search is performed by the cell search circuit by the number of undetected cells calculated by the peripheral cell number calculating circuit.
[0015]
That is, the peripheral cell search method according to the present invention is suitable for the quality Ec / No of the waiting cell (serving cell) and the monitor cell (monitor cell) in the IMT-2000 (International Mobile Telecommunications-2000) type mobile phone device, particularly when waiting. Accordingly, the number of undetected cells is predicted, and only the predicted number of cells is searched, so that unnecessary cell search is omitted and current consumption is reduced.
[0016]
More specifically, in the peripheral cell search method of the present invention, a cell search circuit for detecting a cell, a quality measurement circuit for measuring the quality of the detected cell, and a peripheral cell based on the measured quality A peripheral cell number calculation circuit for calculating the number of cells is provided in the mobile phone device, and the peripheral cell number calculation circuit that can exist in the vicinity based on the quality results of the standby cell and the monitor cell measured by the quality measurement circuit is detected. By calculating the number of cells and giving the number of undetected cells to the cell search circuit, only the number of cells that may exist is searched.
[0017]
Accordingly, in the neighboring cell search method of the present invention, the quality Ec / No of the standby cell and the monitor cell is measured, and the measured quality Ec / No is summed, so that the number of cells that can exist in the vicinity is calculated in advance. Therefore, it is not necessary to perform a cell search more than the number of cells that can exist, so that an unnecessary cell search can be omitted and current consumption can be reduced.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a circuit portion for performing a peripheral cell search in a mobile phone device according to an embodiment of the present invention. In FIG. 1, a mobile phone device 1 is an IMT-2000 (International Mobile Telecommunications-2000) mobile phone device, and includes an antenna 11, a cell search circuit 12, a quality measurement circuit 13, a peripheral cell number calculation circuit 14, and the like. It is composed of
[0019]
The antenna 11 outputs the input received signal to the cell search circuit 12 and the quality measurement circuit 13, respectively. The cell search circuit 12 detects a cell based on the received signal from the antenna 11 and outputs the detected cell to the quality measurement circuit 2.
[0020]
The quality measurement circuit 13 measures the quality of the cells detected by the cell search circuit 12 and outputs the measurement result to the peripheral cell number calculation circuit 14. The peripheral cell number calculation circuit 14 calculates the number of undetected cells that can exist in the vicinity based on the quality results of the standby cell and the monitor cell measured by the quality measurement circuit 13, and performs cell search for the number of undetected cells. Output to the circuit 12.
[0021]
FIG. 2 is a flowchart showing the operation of the mobile phone device 1 of FIG. The operation of the cellular phone device 1 will be described with reference to FIGS.
[0022]
The received signal received by the antenna 11 is subjected to signal analysis by the cell search circuit 12, and a standby cell (Serving Cell) and a monitor cell (Monitor Cell) are determined. The information of the standby cell and the monitor cell is notified to the quality measurement circuit 13, and the quality Ec / No between the standby cell and the monitor cell is measured.
[0023]
The quality information of the standby cell and the monitor cell is input to the peripheral cell number calculation circuit 14, the number of undetected cells that can exist in the periphery is calculated by the peripheral cell number calculation circuit 14, and the calculation result is notified to the cell search circuit 12. The When there is an undetected cell number notified from the peripheral cell number calculation circuit 14, the cell search circuit 12 repeats the search operation so as to detect only the number of undetected cells.
[0024]
For example, the quality measuring circuit 14 measures the quality Ec / No of the standby cell and the monitor cell as shown in FIG. In FIG. 2, as a measurement result,
<Example 1>
Shelving Cell: Ec / No = 3dB
<Example 2>
Shelving Cell: Ec / No = 6dB
Monitor Cell: Ec / No = 6dB
<Example 3>
Shelving Cell: Ec / No = 6dB
Monitor Cell: Ec / No = 12dB
These three examples are illustrated.
[0025]
The operation of the peripheral cell number calculation circuit 14 will be described with reference to FIG. In the IMT-2000 system, P-CPICH (Primary Common Pilot Channel) and P-CCPCH (Primary Common Control Physical Channel), which are always transmitted from a base station (not shown), for example, P-CPICH / P-CCPCH = A case where 0 dB is set will be described.
[0026]
The measurement of quality is generally obtained by measuring Ec / No of P-CPICH [= RSCP (Received Signal Code Power) -RSSI (Receive Signal Strength Indication)].
[0027]
Therefore, in the 1-cell ideal environment, since P-CPICH / PCCPCH = 0 dB, the quality Ec / No becomes −3 dB (step S1 in FIG. 2). Therefore, for example, when the quality Ec / No of the standby cell is −3 dB, there is no cell in the vicinity (step S2 in FIG. 2), so the search for undetected cells is not performed (step S4 in FIG. 2).
[0028]
When the standby cell quality Ec / No is -6 dB, there is a possibility that at least one cell exists in the vicinity (step S2 in FIG. 2). A search for one cell is performed assuming that there is at least one cell (step S3 in FIG. 2).
[0029]
If there is one cell to be monitored, if the quality Ec / No of the monitor cell is −6 dB, no other cell exists, so no undetected cell is searched. When the monitor cell quality Ec / No is less than −6 dB, there is a possibility that another cell exists, and therefore, a search for one cell is performed assuming that there is at least one undetected cell.
[0030]
As described above, in this embodiment, the number of cells that can exist can be calculated from the sum of the quality Ec / No of the standby cell and the monitor cell, and the cell search is performed only when there is a possibility that an undetected cell exists. The circuit 12 is instructed by the peripheral cell number calculation circuit 14 and performs a search operation.
[0031]
As described above, in this embodiment, the number of cells that can exist in the vicinity can be calculated in advance by measuring the quality Ec / No of the standby cell and the monitor cell and summing the measured quality Ec / No. In addition, since it is not necessary to perform cell search more than the number of cells that can exist, unnecessary cell search can be omitted, and current consumption can be reduced.
[0032]
In the present invention, since the power ratio between P-CPICH and P-CCPCH may differ depending on the operator, it exists in the mobile phone device 1 in the vicinity of the sum of the measured quality Ec / No and the calculated sum. By providing a learning function for learning the relationship with the number of possible cells, the number of cells that can exist in the vicinity can be predicted with higher accuracy.
[0033]
Further, in the present invention, when the quality Ec / No of the standby cell and the monitor cell can be calculated that there can be an undetected cell with poor quality, for example, quality Ec / No = −15 dB or less. In addition, since it is not useful to detect a cell having a low quality, it is possible not to perform a search even if the presence of an undetected cell below a certain threshold value can be calculated in advance. As a result, unnecessary searches can be reduced and current consumption can be reduced.
[0034]
Furthermore, in the present invention, the above-described neighboring cell search method can be used during communication. Since the cell phone device 1 constantly performs cell search during communication, there is no effect of reducing current consumption. However, by omitting unnecessary search, the search cycle of the active cell or monitor cell can be accelerated. This makes it possible to search and average with higher accuracy.
[0035]
For example, when Active1, Active2, and Monitor1 are visible and the sum of the quality Ec / No of each cell is equal to the value of a cell that can exist, there is no undetected neighboring cell. Therefore, in this case, it is only necessary to periodically monitor only Active1, Active2, and Monitor1 each time.
[0036]
【The invention's effect】
As described above, according to the present invention having the above-described configuration and operation, an unnecessary cell search can be omitted, and an effect that current consumption can be reduced can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a circuit portion that performs a peripheral cell search in a mobile phone device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing an operation of the mobile phone device of FIG. 1;
FIG. 3 is a block diagram showing a configuration of a circuit portion for performing a peripheral cell search in a mobile phone device according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cellular phone apparatus 11 Antenna 12 Cell search circuit 13 Quality measurement circuit 14 Peripheral cell number calculation circuit

Claims

A cellular phone device that performs a peripheral cell search at a predetermined period when waiting, and means for predicting the number of undetected cells according to the quality of the standby cell and the monitor cell at the time of standby, and the peripheral cell search by the estimated number of cells And a mobile phone device.

A cell search circuit for detecting a cell, a quality measurement circuit for measuring the quality of the cell detected by the cell search circuit, and a peripheral based on the quality results of the standby cell and the monitor cell measured by the quality measurement circuit A peripheral cell number calculating circuit for calculating the number of undetected cells that may exist in the cell search circuit, and performing cell search by the cell search circuit for the number of undetected cells calculated by the peripheral cell number calculating circuit. A mobile phone device.

A learning function for learning a relationship between a quality result of the standby cell and the monitor cell measured by the quality measuring circuit and an undetected cell number calculated by the peripheral cell number calculating circuit, and the peripheral cell number calculating circuit includes: 3. The mobile phone device according to claim 2, wherein the number of undetected cells that can exist in the vicinity is calculated from a learning result of the learning function and a measurement result of the quality measurement circuit.

4. The mobile phone device according to claim 2, wherein the peripheral cell search is suppressed when the number of undetected cells calculated by the peripheral cell number calculation circuit is equal to or less than a preset threshold value.

The peripheral cell number calculating circuit calculates the number of undetected cells during communication,
5. The mobile phone device according to claim 2, wherein the cell search circuit performs the cell search based on a calculation result of the peripheral cell number calculation circuit.

A peripheral cell search method of a mobile phone device that performs a peripheral cell search at a predetermined period when waiting, and predicting the number of undetected cells according to the quality of the standby cell and the monitor cell at the mobile phone device side, A neighboring cell search method, wherein the neighboring cell search is performed by the estimated number of cells.

The quality of the cells detected by the cell search circuit is measured by the quality measurement circuit, and the number of undetected cells that can exist in the vicinity based on the measured quality results of the standby cell and the monitor cell is calculated by the peripheral cell number calculation circuit. A peripheral cell search method comprising: calculating and performing cell search by the cell search circuit for the number of undetected cells calculated by the peripheral cell number calculation circuit.

The relationship between the quality result of the standby cell and the monitor cell measured by the quality measuring circuit and the number of undetected cells calculated by the peripheral cell number calculating circuit is learned by a learning function, and the peripheral cell number calculating circuit 8. The neighboring cell search method according to claim 7, wherein the number of undetected cells that can exist in the vicinity is calculated from a learning result of a learning function and a measurement result of the quality measuring circuit.

The peripheral cell search method according to claim 7 or 8, wherein the peripheral cell search is suppressed when the number of undetected cells calculated by the peripheral cell number calculation circuit is equal to or less than a preset threshold value. .

The peripheral cell number calculating circuit calculates the number of undetected cells during communication,
The peripheral cell search method according to any one of claims 7 to 9, wherein the cell search circuit performs the cell search based on a calculation result of the peripheral cell number calculation circuit.