JPH1169416A - Cellular communication system and mobile equipment and base station used for the same - Google Patents
Cellular communication system and mobile equipment and base station used for the sameInfo
- Publication number
- JPH1169416A JPH1169416A JP15308998A JP15308998A JPH1169416A JP H1169416 A JPH1169416 A JP H1169416A JP 15308998 A JP15308998 A JP 15308998A JP 15308998 A JP15308998 A JP 15308998A JP H1169416 A JPH1169416 A JP H1169416A
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- Japan
- Prior art keywords
- base station
- signal
- transmission
- base stations
- downlink
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、移動通信システ
ム、特に直接拡散符号分割多元接続（ＤＳ−ＣＤＭＡ）
方式を用いた自動車電話・携帯電話システム（セルラシ
ステム）のハンドオーバー技術に関し、属し、特に、移
動機が複数の基地局と同時に接続されているソフトハン
ドオーバー時に、複数の基地局から移動機へ送信するた
めの下り回線の送信電力制御技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more particularly to a direct sequence code division multiple access (DS-CDMA).
The present invention relates to a handover technology for a mobile phone / cellular phone system (cellular system) using the mobile communication method, and particularly to a mobile device from a plurality of base stations during soft handover in which the mobile device is simultaneously connected to the plurality of base stations. The present invention relates to a downlink transmission power control technique for transmission.
【０００２】[0002]
【従来の技術】本技術における従来技術としては、北米
標準のＴＩＡ／ＥＩＡ ＩＳ−９５に準拠した、符号分
割多元接続（ＣＤＭＡ）方式を用いたセルラシステムが
知られている。このＩＳ−９５標準では、ソフトハンド
オーバーという技術が使われている。このソフトハンド
オーバー技術が使用されるシステムでは、移動機がセル
（またはセクタ）境界に近づいたときには、その移動機
は、この境界近辺のセルをサービスエリアとする複数の
基地局と同時に通信を行う すなわち、移動機が現在通信中の基地局以外に受信レベ
ルの大きい基地局を検出すると、移動機は自身がセル境
界に近づいたと判断し、現基地局及び受信レベルが大き
な他の基地局との複数の基地局との通信を開始する。そ
して、移動機は、複数の基地局から同じ下り情報を受信
し、移動機では複数の基地局からの下り情報を最大比合
成ダイバーシティ受信する。2. Description of the Related Art As a prior art of the present technology, a cellular system using a code division multiple access (CDMA) system conforming to TIA / EIA IS-95 of the North American standard is known. The IS-95 standard uses a technique called soft handover. In a system using the soft handover technique, when a mobile device approaches a cell (or sector) boundary, the mobile device simultaneously communicates with a plurality of base stations having a cell near the boundary as a service area. That is, when the mobile station detects a base station having a high reception level other than the base station with which it is currently communicating, the mobile station determines that it has approached a cell boundary, and determines whether the mobile station has a current base station and another base station having a high reception level. Start communication with a plurality of base stations. Then, the mobile device receives the same downlink information from a plurality of base stations, and the mobile device receives downlink information from the multiple base stations at the maximum ratio combining diversity.
【０００３】移動機の送信する上り情報は、複数の基地
局で受信されてこれら複数の基地局を統括する基地局制
御装置（ＢＳＣ； Base Station Contoller）に伝えら
れる。基地局制御装置は、これら複数の基地局で受信さ
れた上り信号を、最大比合成受信あるいは選択ダイバー
シティ受信する。移動機がセル境界に位置するときは、
基地局における上り信号の受信品質が低下するが、ＢＳ
Ｃにおいて複数の基地局の上り信号受信結果を合成ある
いは選択ダイバーシティ受信することにより、この上り
信号の受信品質低下を緩和できる。[0003] Uplink information transmitted by a mobile station is received by a plurality of base stations and transmitted to a base station controller (BSC) controlling the plurality of base stations. The base station controller receives the uplink signals received by the plurality of base stations at the maximum ratio combining reception or the selection diversity reception. When the mobile is located at the cell boundary,
Although the reception quality of the uplink signal in the base station decreases,
By combining or selecting diversity reception of uplink signal reception results of a plurality of base stations in C, it is possible to mitigate the decrease in the reception quality of the uplink signal.
【０００４】また、移動機がセル境界付近に位置する
と、基地局からの距離が離れているので基地局からの下
り信号の受信レベルが低下する。また、セル境界では、
複数のセルからの干渉を受けるため回線品質が劣化しが
ちであるが、このように複数の基地局と接続する（ソフ
トハンドオーバー）ことにより、下り回線品質の劣化を
防ぐことができる。When a mobile station is located near a cell boundary, the reception level of a downlink signal from the base station decreases because the mobile station is far from the base station. At the cell boundary,
Although the line quality tends to deteriorate due to interference from a plurality of cells, by connecting to a plurality of base stations (soft handover) in this way, it is possible to prevent the deterioration of the downlink quality.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、ＩＳ−
９５等の従来技術では、ソフトハンドオーバー中は、複
数の基地局から下り信号を同時に送信していたため、ソ
フトハンドオーバー技術を使用しないセルラーシステム
に比して、使用中の下り回線数が著しく増加する。すな
わち、ソフトハンドオーバー中の移動機の台数が増える
と、下り回線容量がネックとなって同時使用できる回線
数が制限されるため、回線の有効利用が計れなくなると
いう潜在的な問題があった。However, the IS-
In conventional techniques such as 95, during soft handover, downlink signals are simultaneously transmitted from a plurality of base stations, so the number of downlinks in use increases significantly compared to a cellular system that does not use soft handover technology. I do. In other words, when the number of mobile units during soft handover increases, the number of lines that can be used simultaneously is limited due to a bottleneck in downlink capacity, and there is a potential problem that effective utilization of lines cannot be measured.
【０００６】しかるに、ＩＳ９５では、下り回線の伝送
方式の方が上り回線の伝送方式に比べて効率が良かった
ため、上記のような複数の基地局から下り信号を送信す
るという、一見すると、非効率的な方法を用いても、下
り回線容量がネックになることはなかった。However, in IS95, the downlink transmission system is more efficient than the uplink transmission system, so that downlink signals are transmitted from a plurality of base stations as described above. Even with the conventional method, the downlink capacity did not become a bottleneck.
【０００７】しかし、現在、上り回線容量が下り回線容
量と同等に改善されつつあるため、ソフトハンドオーバ
ーによる下り回線容量の劣化を解決する必要が生じてい
る。However, at present, the uplink capacity is being improved to the same level as the downlink capacity, and it is necessary to solve the degradation of the downlink capacity due to soft handover.
【０００８】それ故に、本発明の主たる目的は、ＣＤＭ
Ａ方式を採用した移動通信システムにおいて、セルある
いはセクタ境界に位置する端末に対するソフトハンドオ
ーバー中の下り送受信方式を改良することにより、下り
回線の効率を向上することができるソフトハンドオーバ
ー方式を提供することにある。[0008] Therefore, the main object of the present invention is to provide a CDM.
In a mobile communication system employing the A scheme, a soft handover scheme capable of improving downlink efficiency by improving a downlink transmission / reception scheme during soft handover to a terminal located at a cell or sector boundary is provided. It is in.
【０００９】[0009]
【課題を解決するための手段】本発明は、直接拡散符号
分割多元接続方式を用いたセルラシステムであり、移動
機が複数の基地局とソフトハンドオーバーを行うセルラ
システムであり、前記移動機は、前記ソフトハンドオー
バー状態にある複数の基地局からの下り信号の受信品質
をモニタする下り受信品質モニタ手段と； 前記複数の
下り受信品質モニタ結果に従って送信すべき基地局を指
示する信号を送出する基地局指定手段と； 前記基地局
指定信号を上り信号に多重化して前記複数の基地局に送
信する多重化手段と； 前記ハンドオーバー状態にある
複数の基地局からの受信信号を合成受信する受信手段と
を含み、前記基地局は、前記上り信号に多重化された基
地局指定信号を復調する復調手段と； 前記復調された
基地局指定信号に従って、該当する移動機への下り送信
信号の送信を制御する送信制御手段；とを含む。SUMMARY OF THE INVENTION The present invention is a cellular system using a direct spreading code division multiple access system, wherein a mobile station performs soft handover with a plurality of base stations. Downlink reception quality monitoring means for monitoring reception quality of downlink signals from a plurality of base stations in the soft handover state; and transmitting a signal indicating a base station to be transmitted according to the plurality of downlink reception quality monitoring results. Base station designating means; multiplexing means for multiplexing the base station designating signal into an uplink signal and transmitting the multiplexed signal to the plurality of base stations; reception for combining and receiving received signals from the plurality of base stations in the handover state And demodulation means for demodulating a base station designation signal multiplexed on the uplink signal; and demodulation means according to the demodulated base station designation signal. Transmission control means for controlling transmission of a downlink transmission signal to a corresponding mobile station.
【００１０】移動局はハンドオーバー中の複数の基地局
からの下り信号の品質をモニタし、品質の最も良い基地
局を指定する信号を上り信号に多重化して送り返すこと
により、ハンドオーバー中でも回線状態の良い基地局の
み下り送信を行い、その他の基地局の送信を停止するこ
とが可能となり、下り回線の周波数利用効率を高めるこ
とができる。The mobile station monitors the quality of downlink signals from a plurality of base stations during handover, multiplexes a signal designating the base station with the best quality into an uplink signal and sends it back, so that the line condition is maintained even during handover. It is possible to perform downlink transmission only for base stations with good transmission and stop transmission of other base stations, thereby improving downlink frequency utilization efficiency.
【００１１】[0011]
【発明の実施の形態】次に本発明につき、図面を参照し
ながら説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.
【００１２】図１は本発明に係る第１の実施形態に係る
移動機の構成を示すブロック図、図２は本発明にの第１
の実施形態に係る係る基地局の構成を示すブロック図で
ある。FIG. 1 is a block diagram showing a configuration of a mobile station according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing a first embodiment of the present invention.
FIG. 9 is a block diagram showing a configuration of a base station according to the embodiment.
【００１３】図１に示されるとおり、本発明の第１の実
施形態に係る移動機は、１または複数の基地局から無線
信号を受信するアンテナ１０１と；送受共用器（デュー
プレクサ；ＤＵＰ）１０２と、無線信号を受信ベースバ
ンド信号に変換する無線受信部（Ｒｘ）１０３と；ハン
ドオーバー中の複数の基地局のパイロット信号を受信
し、受信品質をモニタする受信品質モニタ手段１０４
と；複数の基地局の下り回線品質のモニタ結果から、受
信品質の良い基地局を選択し、この受信品質の良い基地
局に対応する基地局指定信号（ＢＳｓｅｌ）を出力する
基地局指定手段１０５と；、この基地局指定信号（ＢＳ
ｓｅｌ）を含む付随制御チャネルと上り通信チャネルデ
ータ（ｒ−ｔｘｄ）を多重化し上り送信信号を生成する
マルチプレクサ（ＭＵＸ）１０９と；上り送信信号を拡
散し、送信ベースバンド信号を出力する拡散回路１１０
と；送信ベースバンド信号を無線信号に変換して送信す
る無線送信部（Ｔｘ）１１１と；ハンドオーバー状態に
ある複数の基地局からの受信ベースバンド信号を合成受
信するＲＡＫＥ受信機１０８とにより構成されている。As shown in FIG. 1, a mobile station according to a first embodiment of the present invention includes an antenna 101 for receiving a radio signal from one or a plurality of base stations; a duplexer (DUP) 102; A radio reception unit (Rx) 103 for converting a radio signal into a reception baseband signal; reception quality monitoring means 104 for receiving pilot signals of a plurality of base stations during handover and monitoring reception quality
And base station specifying means 105 for selecting a base station having good reception quality from the results of monitoring the downlink qualities of a plurality of base stations and outputting a base station specifying signal (BSsel) corresponding to the base station having good reception quality. And this base station designation signal (BS
sel) and a multiplexer (MUX) 109 for multiplexing the uplink communication channel data (r-txd) including the uplink communication channel data (r-txd); and a spreading circuit 110 for spreading the uplink transmission signal and outputting a transmission baseband signal.
A radio transmission unit (Tx) 111 that converts a transmission baseband signal into a radio signal and transmits the radio signal; and a RAKE receiver 108 that combines and receives reception baseband signals from a plurality of base stations in a handover state. Have been.
【００１４】ＲＡＫＥ受信機１０８は相関器１０６と、
下り通信チャネルデータ（ｆ−ｔｘｄ）を出力する最大
比合成器１０７とを有している。The RAKE receiver 108 includes a correlator 106,
A maximum ratio combiner 107 for outputting downlink communication channel data (f-txd).
【００１５】移動機の下り受信品質モニタ手段１０４
は、基地局のそれぞれからすべての移動機に対して常時
送信されるパイロットチャネルを用いて受信品質を測定
する。[0015] Downlink reception quality monitoring means 104 of the mobile station
Measures reception quality using a pilot channel that is constantly transmitted from each of the base stations to all mobile stations.
【００１６】基地局指定手段１０５は、複数の基地局の
下り受信品質が良い基地局を選択し、選択された基地局
を示す基地局指定信号を出力する。この選択の基準とし
ては、例えば、次の基準のいずれでも使用することがで
きる。 （１）最良の受信品質を示す基地局と、この最良の受信
品質との差が小である基地局とを選択する。 （２）受信品質の良い順に、現在ハンドオーバー対象と
なっている基地局の数以下の所定数の、基地局を選択す
る。 （３）受信品質が予め定められた値よりも大きな基地局
を選択する。ただし、全ての基地局の受信品質が全てこ
の予め定められた値より小さい場合には、受信品質の良
い順に所定数の基地局を選択する。この付加的な条件
は、ソフトハンドオーバー状態にある全ての基地局の、
移動機での下り信号受信品質が低い場合に、全ての基地
局が送信停止してしまうことを防止するために設けられ
ている。The base station designating means 105 selects a base station having a good downlink reception quality of a plurality of base stations, and outputs a base station designating signal indicating the selected base station. As a criterion for this selection, for example, any of the following criteria can be used. (1) Select a base station exhibiting the best reception quality and a base station having a small difference from the best reception quality. (2) Select a predetermined number of base stations equal to or less than the number of base stations that are currently subject to handover in order of good reception quality. (3) Select a base station whose reception quality is larger than a predetermined value. However, when the reception qualities of all the base stations are all smaller than the predetermined value, a predetermined number of base stations are selected in descending order of the reception qualities. This additional condition applies to all base stations in soft handover state.
This is provided to prevent all base stations from stopping transmission when the reception quality of the downlink signal at the mobile device is low.
【００１７】図２を参照すると、本発明の第１の実施形
態に係る基地局は、複数の通信チャネルで共通に利用す
る共通部と、通信チャネル毎に分かれたチャネル部２０
８とに分けることができる。Referring to FIG. 2, a base station according to the first embodiment of the present invention includes a common unit commonly used for a plurality of communication channels, and a channel unit 20 divided for each communication channel.
8 can be divided.
【００１８】共通部は、移動機からの無線信号を受信す
るアンテナ２０１と、送受共用器（デュープレクサ；Ｄ
ＵＰ）２０２と；無線信号を受信ベースバンド信号に変
換する無線受信部（Ｒｘ）２０３と；パイロットチャネ
ル（ＰＬＣＨ）を拡散する拡散回路２１８と、パイロッ
トチャネルおよび複数のチャネル部２０８からの複数の
チャネルの送信信号を加算合成する加算器２０９とで構
成される。これら、パイロットチャネルと複数の通信チ
ャネルとでは、使用される拡散符号が異なっている。The common unit includes an antenna 201 for receiving a radio signal from a mobile station and a duplexer (duplexer; D).
UP) 202; a radio receiving unit (Rx) 203 for converting a radio signal into a received baseband signal; a spreading circuit 218 for spreading a pilot channel (PLCH); and a plurality of channels from a pilot channel and a plurality of channel units 208 And an adder 209 for adding and combining the transmission signals of the above. These pilot channels and the plurality of communication channels use different spreading codes.
【００１９】通信チャネル毎に必要なチャネル部２０８
は、マルチパス伝搬路を経由した受信信号を逆拡散して
最大比合成するＲＡＫＥ受信機２０４と；ＲＡＫＥ受信
機２０４出力から上り通信チャネルデータ（ｒ−ｒｘ
ｄ）と基地局指定信号（ＢＳｓｅｌ）を含む付随制御チ
ャネルとを分離するデマルチプレクサ（ＤＭＵＸ）２０
５と；下り通信チャネルデータ（ｆ−ｔｘｄ）を拡散す
る拡散器２０６と、移動機からの付随制御チャネルデー
タに含まれている基地局指定信号（ＢＳｓｅｌ）に従っ
て、送信のＯＮ／ＯＦＦを制御する送信制御手段２０７
と、により構成されている。Channel unit 208 required for each communication channel
Is a RAKE receiver 204 for despreading a received signal that has passed through a multipath propagation path and performing maximum ratio combining; and uplink communication channel data (r-rx
d) and a demultiplexer (DMUX) 20 for separating an associated control channel including a base station designation signal (BSsel).
5; ON / OFF of transmission is controlled according to a spreader 206 for spreading downlink communication channel data (f-txd) and a base station designation signal (BSsel) included in accompanying control channel data from the mobile station. Transmission control means 207
, And is constituted.
【００２０】次に本発明の第１の実施の形態例の動作に
ついて図３を参照して説明する。図３はこれから説明す
るソフトハンドオーバー動作を行う時の移動機の動きを
示す図である。Next, the operation of the first embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram showing the movement of the mobile station when performing the soft handover operation described below.
【００２１】移動機（ＭＳ）３０３が、基地局（ＢＳ
１）３０１のサービスエリアから基地局（ＢＳ２）３０
２のサービスエリアに移動し、２つの基地局３０１，３
０２のサービスエリアが重なる部分に位置すると、基地
局（ＢＳ２）３０２は、移動機からの上り信号が受信可
能となり、基地局（ＢＳ２）３０２は、移動機３０３か
らの上り信号の受信が可能になった旨を基地局制御装置
に伝える。すると基地局制御装置は、基地局（ＢＳ１）
３０１からの上り信号と基地局（ＢＳ２）３０２からの
上り信号とを最大比合成受信あるいは選択ダイバーシテ
ィ受信して、その結果を移動通信用交換機（ＭＳＣ）に
転送する。また、基地局制御装置は、それまで基地局
（ＢＳ１）３０１にのみ伝えていた移動通信用交換機か
ら移動機３０３への下り信号を、基地局（ＢＳ２）３０
２にも転送する。この動作については、ＩＳー９５標準
等に規定された従来技術と同様である。A mobile station (MS) 303 is connected to a base station (BS)
1) From the service area 301 to the base station (BS2) 30
2 to the two service areas 301 and 3
When the service area 02 is located in the overlapping area, the base station (BS2) 302 can receive the uplink signal from the mobile device, and the base station (BS2) 302 can receive the uplink signal from the mobile device 303. It informs the base station control device that it has become. Then, the base station control device sets the base station (BS1)
The uplink signal from the base station (BS2) 302 and the uplink signal from the base station (BS2) 302 are subjected to maximum ratio combining reception or selective diversity reception, and the result is transferred to the mobile switching center (MSC). Further, the base station controller transmits the downlink signal from the mobile communication exchange to the mobile station 303, which has been transmitted only to the base station (BS1) 301, to the base station (BS2) 30.
Also transfer to 2. This operation is the same as in the prior art defined in the IS-95 standard or the like.
【００２２】次に、本発明の根幹をなす、移動機及び基
地局の下り信号に対する動作につき説明する。この図３
の例では、前述した選択基準は、全て一致することとな
り、良い受信品質を示した方の基地局のみが選択され、
選択されなかった基地局は、移動通信用交換機（ＭＳ
Ｃ）、基地局制御装置（ＢＳＣ）を介して供給された下
り信号の送信を停止する。Next, a description will be given of the operation of the mobile station and the base station with respect to a downlink signal, which is the basis of the present invention. This figure 3
In the example of the above, all the selection criteria described above match, and only the base station that shows good reception quality is selected,
The base station not selected is a mobile communication exchange (MS).
C) The transmission of the downlink signal supplied via the base station controller (BSC) is stopped.
【００２３】基地局３０１、３０２の送信制御手段２０
７は、基地局指定信号が自基地局を指定していない場合
には、送信を停止する。また、送信制御手段２０７は、
基地局指定信号が自基地局を指定している場合および基
地局指定信号に伝送誤りを検出した場合に移動機への送
信を行い、それ以外の場合に送信を停止する。Transmission control means 20 of base stations 301 and 302
7 stops transmission when the base station designation signal does not designate its own base station. Further, the transmission control means 207
The transmission to the mobile station is performed when the base station designation signal designates the own base station and when a transmission error is detected in the base station designation signal, and otherwise, the transmission is stopped.
【００２４】図４は、この時の基地局３０１および基地
局３０２の下り受信品質の遷移、および、各基地局（Ｂ
Ｓ１，ＢＳ２）３０１，３０２の送信ＯＮ／ＯＦＦのタ
イミングを示すタイムチャートである。FIG. 4 shows the transition of the downlink reception quality of the base station 301 and the base station 302 at this time, and each base station (B
5 is a time chart showing transmission ON / OFF timings of (S1, BS2) 301 and 302.
【００２５】従来方式（例えばＩＳ９５）では、図４
ａ）、ｂ）に示されるとおり、２つの基地局の受信品質
差が一定値より小さくなるとソフトハンドオーバー状態
に入り、２つの基地局で移動機に送信を開始する。この
ソフトハンドオーバー状態は、２つの基地局の受信品質
差が一定値以上に開き、完全に新しい基地局（ＢＳ２）
３０２のサービスエリアに入るまで継続される。すなわ
ち、従来例では、ソフトハンドオーバー中は２つの基地
局で送信を行っている。In the conventional system (for example, IS95), FIG.
As shown in a) and b), when the difference between the reception qualities of the two base stations becomes smaller than a certain value, a soft handover state is entered, and the two base stations start transmitting to the mobile station. In this soft handover state, the reception quality difference between the two base stations opens above a certain value, and a completely new base station (BS2)
The process is continued until the service area 302 is entered. That is, in the conventional example, transmission is performed by two base stations during soft handover.
【００２６】一方、図４ｃ）〜ｅ）は本発明の一実施例
における、基地局指定信号および２つの基地局（ＢＳ
１，ＢＳ２）３０１，３０２の送信ＯＮ／ＯＦＦのタイ
ミングを示している。ハンドオーバー中も受信品質の変
化に伴って、基地局指定信号が変化し、常に伝搬状態の
良い片方の基地局からのみ送信が行われることを示して
いる。On the other hand, FIGS. 4C to 4E show a base station designation signal and two base stations (BS) in one embodiment of the present invention.
1, BS2) 301, 302 indicate the transmission ON / OFF timing. Even during the handover, the base station designation signal changes with the change of the reception quality, indicating that transmission is performed only from one base station having a good propagation state at all times.
【００２７】この図３の例における、ソフトハンドオー
バーの手順は次の通りである。 ［１］従来技術と同様に、移動機３０３は周辺基地局の
パイロットチャネルの受信品質を測定し基地局に報告す
る。現在通信中の基地局のパイロットチャネルの受信品
質と一定差以内の基地局が検出されると、ソフトハンド
オーバー状態に入る。 ［２］基地局より、ソフトハンドオーバー状態の基地局
とその番号を移動機に通知する。 ［３］ソフトハンドオーバー状態の複数の基地局は、従
来と同様、移動機の上り情報を最大比合成あるいは選択
ダイバーシティ受信する。 ［４］移動機はソフトハンドオーバー状態の基地局のパ
イロットチャネルの品質をモニタし、最も品質の良い基
地局の番号を上り回線の付随制御チャネルを用いて、ソ
フトハンドオーバー状態の全基地局に通知する。品質測
定・通知は、レイリーフェージングに追従する必要はな
く、建物の陰に入る等の伝播経路の変化（シャドウイン
グ）に追従できればよい。 ［５］移動機３０３に指示された基地局のみ下り情報を
送信する。上り回線の誤り等により、１局も下り情報を
送信しない危険があるが、付随制御チャネルのＣＲＣで
誤りを検出した基地局でも送信する等の方法により避け
ることが可能である。 ［６］移動機３０３は複数の基地局からの信号を選択あ
るいは最大比合成により受信する。 ［７］パイロットチャネルの受信品質の差が一定値以上
になったときは、ソフトハンドオーバ状態を解除する。The procedure of the soft handover in the example of FIG. 3 is as follows. [1] As in the prior art, the mobile station 303 measures the reception quality of the pilot channel of the peripheral base station and reports it to the base station. When a base station within a certain difference from the reception quality of the pilot channel of the base station that is currently communicating is detected, a soft handover state is entered. [2] The base station notifies the mobile station of the base station in the soft handover state and its number. [3] The plurality of base stations in the soft handover state receive the uplink information of the mobile station at the maximum ratio combining or selective diversity reception as in the related art. [4] The mobile station monitors the quality of the pilot channel of the base station in the soft handover state, and assigns the number of the base station with the highest quality to all the base stations in the soft handover state using the associated control channel of the uplink. Notice. The quality measurement / notification does not need to follow the Rayleigh fading, but only needs to be able to follow a change in the propagation path (shadowing) such as entering the shadow of a building. [5] Only the base station instructed by the mobile station 303 transmits downlink information. Although there is a danger that none of the stations will transmit the downlink information due to an uplink error or the like, it can be avoided by a method such as transmitting even the base station that has detected the error by the CRC of the associated control channel. [6] The mobile station 303 receives signals from a plurality of base stations by selection or maximum ratio combining. [7] When the difference between the reception qualities of the pilot channels becomes equal to or more than a certain value, the soft handover state is released.
【００２８】このような手順で基地局および移動機３０
３が動作する事により、ソフトハンドオーバー状態で
も、伝搬品質の良い一部の基地局のみが、下り送信を行
うことになり、伝搬品質の悪い基地局からは下り送信を
行なわなくて済むため、下り回線の周波数利用効率を改
善することができる。In this manner, the base station and the mobile station 30
3 operates, even in the soft handover state, only some base stations with good propagation quality perform downlink transmission, and do not need to perform downlink transmission from base stations with poor propagation quality. It is possible to improve the frequency utilization efficiency of the downlink.
【００２９】移動機３０３は、基地局サーチおよび同期
検波を行うために、基地局毎に全回線で共通利用するパ
イロットチャネルを用いて下り回線品質の測定を行うた
め、送信停止状態の基地局の下り回線品質もモニタ可能
である。したがって、移動機は、その移動機に対する下
り通信を停止している基地局に、下り送信の再開をしじ
できる。The mobile station 303 measures downlink quality using a pilot channel shared by all base stations for base station search and synchronous detection. Downlink quality can also be monitored. Therefore, the mobile station can restart downlink transmission to the base station that has stopped downlink communication with the mobile station.
【００３０】複数の基地局の下り回線品質がほぼ同等
で、最大比合成により複数の基地局からの受信信号を無
駄なく合成可能と判断した場合は、移動機３０３は該当
する複数の基地局に対して下り送信を指示することによ
り、ダイバーシティゲインを得ることも可能である。If it is determined that the downlink quality of the plurality of base stations is substantially equal and the signals received from the plurality of base stations can be combined without waste by the maximum ratio combining, the mobile station 303 transmits to the corresponding plurality of base stations. It is also possible to obtain a diversity gain by instructing downlink transmission.
【００３１】また、すべての基地局の下り回線品質がす
べて劣化しており、１局の送信では所要品質を満たすこ
とができないと判断した場合は、移動機は受信品質が比
較的良い複数の基地局に対して下り送信を指示すること
により、所要受信品質を得ることが可能である。If it is determined that the downlink quality of all the base stations is degraded and that the transmission of one station cannot satisfy the required quality, the mobile station transmits to a plurality of base stations having relatively good reception quality. By instructing the station to perform downlink transmission, it is possible to obtain required reception quality.
【００３２】移動機３０３の送信する基地局指定信号の
受信を誤ることを想定しなければならない。特にソフト
ハントオーバーが複数の基地局にまたがる場合、各基地
局の復調結果が異なり、どの基地局も送信指示されてい
ないと判断する可能性がある。このようなケースを避け
るため、復調結果に誤りを検出した場合は自局の送信が
指示されていない場合にも送信することにより、すべて
の基地局が送信しない確率を非常に小さくすることがで
きる（上記手順［５］）。It must be assumed that the base station designation signal transmitted by the mobile station 303 is erroneously received. In particular, when the soft huntover extends over a plurality of base stations, the demodulation results of each base station are different, and it may be determined that no base station has been instructed to transmit. In order to avoid such a case, when an error is detected in the demodulation result, by transmitting even when transmission of the own station is not instructed, the probability that all base stations do not transmit can be extremely reduced. (Procedure [5] above).
【００３３】しかしながら、複数の基地局で基地局指定
信号の復調結果が同一であると保証できる場合は、誤り
検出の有無に関わらず、基地局指定信号の通りに送信を
ＯＮ／ＯＦＦすればよい。例えば、ソフトハンドオーバ
ーが１基地局内の複数のセクターの場合は、基地局指定
信号の復調結果をセクタ間で共通とすることが容易に可
能であるから、基地局指定信号の通りに送信セクタを選
択しても良い。However, when it is possible to guarantee that the demodulation result of the base station designation signal is the same at a plurality of base stations, the transmission may be turned on / off as the base station designation signal regardless of whether an error is detected. . For example, when the soft handover is performed for a plurality of sectors within one base station, it is easy to make the demodulation result of the base station designation signal common among the sectors. You may choose.
【００３４】次に、図５及び図６を参照して、本発明の
第２の実施形態を説明する。図５は、本発明の第２の実
施形態に係る移動機の構成を示すブロック図であり、図
６は、本発明の第２の実施形態に係る基地局の構成を示
すブロック図である。Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram illustrating a configuration of a mobile device according to the second embodiment of the present invention, and FIG. 6 is a block diagram illustrating a configuration of a base station according to the second embodiment of the present invention.
【００３５】図１と図５との比較から明らかなように、
第２の実施形態の移動機は、第１の実施形態が備えてい
た基地局指定手段１０５を備えていない。その代わり
に、第２の実施形態に係る移動機では、当該移動機が受
信可能な基地局のパイロット信号の受信品質モニターの
モニター結果が、対応する基地局を特定する信号ととも
にマルチプレクサ１０９に供給される。マルチプレクサ
１０９ａは、受信品質モニター出力と上り通信チャネル
データ（ｒ−ｔｘｄ）を多重化し上り送信信号を生成
し、拡散回路１１０に供給する。図５のその他の構成要
素の動作は、図１に示した移動機と同様である。As is clear from the comparison between FIG. 1 and FIG.
The mobile station according to the second embodiment does not include the base station specifying means 105 provided in the first embodiment. Instead, in the mobile station according to the second embodiment, the monitoring result of the reception quality monitor of the pilot signal of the base station receivable by the mobile station is supplied to the multiplexer 109 together with a signal specifying the corresponding base station. You. The multiplexer 109a multiplexes the reception quality monitor output and the uplink communication channel data (r-txd) to generate an uplink transmission signal, and supplies the uplink transmission signal to the spreading circuit 110. The operation of the other components in FIG. 5 is the same as that of the mobile device shown in FIG.
【００３６】また、図２と図６との比較から明らかなよ
うに、第２の実施形態の基地局は、ＲＡＫＥ受信機２０
４と送信制御手段２０７との間に、ＲＡＫＥ受信機２０
４出力から「上り通信チャネルデータ（ｒ−ｒｘｄ）」
と移動機（図５）が検出したパイロット信号の受信品質
及びそれに対応する基地局を特定する信号」とを分離す
るデマルチプレクサ（ＤＭＵＸ）２０５と；これら受信
品質及びそれに対応する基地局を特定する信号から、パ
イロット信号を除く自局の送信を停止するか否かを示す
送信停止信号を生成し送信制御手段２０７に供給する送
信停止信号生成手段１０５ａとを備えている。なお、こ
の送信停止信号生成手段１０５ａの構成・動作は、図１
の基地局指定手段と同様である。また、図６に於いて、
説明を省略した構成要素の動作は、図２で同一参照符号
を付したものと同様である。As is clear from the comparison between FIG. 2 and FIG. 6, the base station according to the second embodiment includes a RAKE receiver 20.
4 and the transmission control means 207, the RAKE receiver 20
"Uplink communication channel data (r-rxd)" from 4 outputs
A demultiplexer (DMUX) 205 for separating the reception quality of the pilot signal detected by the mobile station (FIG. 5) and a signal specifying the base station corresponding to the pilot signal; and specifying the reception quality and the corresponding base station. A transmission stop signal generation unit 105 a that generates a transmission stop signal indicating whether to stop transmission of the own station excluding a pilot signal from the signal and supplies the transmission stop signal to the transmission control unit 207. The configuration and operation of the transmission stop signal generation means 105a are the same as those shown in FIG.
This is the same as the base station designating means. In FIG. 6,
The operations of the constituent elements whose description is omitted are the same as those in FIG.
【００３７】以上の説明から明らかなように、第１の実
施形態と第２の実施形態とは、次の点で異なっている。
第１の実施形態では、ソフトハンドオーバー時に、どの
基地局の下り送信を停止させるかの決定は移動局側が決
定していた。これに対して、第２の実施形態は、ソフト
ハンドオーバー時に、どの基地局の下り送信を停止させ
るかの決定は基地局が行っている。この第２の実施形態
では、第１の実施形態で不可欠であった、移動機（図
１）の基地局指定手段１０５が不要となるので、移動機
を第１の実施形態よりも小型化できる。また、移動機の
消費電力も、第２の実施形態の方が、第１の実施形態よ
りも小とすることができる。As is clear from the above description, the first embodiment differs from the second embodiment in the following points.
In the first embodiment, the mobile station determines which base station should stop downlink transmission during soft handover. On the other hand, in the second embodiment, at the time of soft handover, the base station determines which base station should stop downlink transmission. In the second embodiment, since the base station designating means 105 of the mobile device (FIG. 1), which is indispensable in the first embodiment, is not required, the mobile device can be made smaller than in the first embodiment. . Also, the power consumption of the mobile device can be made smaller in the second embodiment than in the first embodiment.
【００３８】なお、第２の実施形態の送信停止信号生成
手段１０５ａが送信停止信号を出力する基準としては、
例えば、次の３つのいずれかを用いることができる。 （１ａ）自局の移動機での下り信号受信品質が、最良の
受信品質を示す基地局の下り信号受信品質との差が大で
ある場合に、送信停止信号を出力する。 （２ａ）自局の移動機での下り信号受信品質が、受信品
質の良い順に、所定の順位より下位であるときは、送信
停止信号を出力する。 （３ａ）自局の移動機での下り信号受信品質が予め定め
られた値よりも小さな値のとき、送信停止信号を出力す
る。ただし、全ての基地局の受信品質が全てこの予め定
められた値より小さい場合には、自局の受信品質が、受
信品質の良い順に所定の順位より上位である場合には、
下り信号受信品質が予め定められた値よりも小さな値で
あっても、送信停止信号を出力しない。この付加的な条
件は、ソフトハンドオーバー状態にある全ての基地局
の、移動機での下り信号受信品質が低い場合に、全ての
基地局が送信停止してしまうことを防止するために設け
られている。The transmission stop signal generating means 105a of the second embodiment outputs a transmission stop signal based on the following criteria.
For example, any of the following three can be used. (1a) When the difference between the downlink signal reception quality of the mobile station of the own station and the downlink signal reception quality of the base station exhibiting the best reception quality is large, a transmission stop signal is output. (2a) If the downlink signal reception quality at the mobile station of the own station is lower than a predetermined order in descending order of the reception quality, a transmission stop signal is output. (3a) When the downlink signal reception quality at the mobile station of the own station is smaller than a predetermined value, the mobile station outputs a transmission stop signal. However, if the reception qualities of all base stations are all smaller than the predetermined value, if the reception quality of the own station is higher than a predetermined order in descending order of the reception quality,
Even if the downlink signal reception quality is smaller than a predetermined value, the transmission stop signal is not output. This additional condition is provided in order to prevent all base stations from stopping transmission when the quality of downlink signal reception at the mobile device of all base stations in the soft handover state is low. ing.
【００３９】[0039]
【発明の効果】以上述べたとおり、本発明では、ソフト
ハンドオーバー中も最も受信品質の良い少数の基地局か
らのみ下り送信が行われるため、下り回線の周波数利用
効率が損なわれない。従って、本発明の採用により、下
り回線の容量がネックとなって回線容量が制約されるこ
とを回避することができる。また、本発明では、ソフト
ハンドオーバー状態であっても伝搬状態の悪い基地局は
送信しないため、基地局の平均送信電力を下げることが
でき、基地局の送信パワーアンプを簡易化できる。As described above, according to the present invention, even during soft handover, only a small number of base stations having the best reception quality perform downlink transmission, so that the frequency utilization efficiency of the downlink is not impaired. Therefore, by adopting the present invention, it is possible to avoid that the capacity of the downlink becomes a bottleneck and the capacity of the line is restricted. Further, in the present invention, even in a soft handover state, a base station in a poor propagation state does not transmit, so that the average transmission power of the base station can be reduced and the transmission power amplifier of the base station can be simplified.
【図１】本発明の第１の実施形態に係る移動機の構成を
示すブロック図である。FIG. 1 is a block diagram illustrating a configuration of a mobile device according to a first embodiment of the present invention.
【図２】本発明の第１の実施形態に係る基地局の構成を
示すブロック図である。FIG. 2 is a block diagram illustrating a configuration of a base station according to the first embodiment of the present invention.
【図３】本発明のソフトハンドオーバー動作に入る移動
機の動きを示す図である。FIG. 3 is a diagram illustrating the movement of a mobile station entering a soft handover operation according to the present invention.
【図４】本発明および従来例における受信品質と送信Ｏ
Ｎ／ＯＦＦタイミングを示すタイムチャートである。FIG. 4 shows reception quality and transmission O in the present invention and the conventional example.
It is a time chart which shows N / OFF timing.
【図５】本発明の第２の実施形態に係る移動機の構成を
示すブロック図である。FIG. 5 is a block diagram illustrating a configuration of a mobile device according to a second embodiment of the present invention.
【図６】本発明の第２の実施形態に係る基地局の構成を
示すブロック図である。FIG. 6 is a block diagram illustrating a configuration of a base station according to a second embodiment of the present invention.
１０１、２０１ アンテナ １０２、２０２ 送受共用器 １０３、２０３ 無線受信部 １０４ 受信品質モニタ手段 １０５ 基地局指定手段 １０６ 相関器 １０７ 最大比合成器 １０８、２０４ ＲＡＫＥ受信機 １０９ マルチプレクサ １１０、２０６、２１８ 拡散回路 １１０、２１０ 無線送信部 ２０５ デマルチプレクサ ２０７ 送信制御手段 ２０８ チャネル部 ２０９ 加算器 ３０１、３０２ 基地局 ３０３ 移動機 101, 201 antenna 102, 202 duplexer 103, 203 radio receiver 104 reception quality monitoring means 105 base station designation means 106 correlator 107 maximum ratio combiner 108, 204 RAKE receiver 109 multiplexer 110, 206, 218 spreading circuit 110 , 210 Radio transmission section 205 Demultiplexer 207 Transmission control means 208 Channel section 209 Adder 301, 302 Base station 303 Mobile station
Claims (24)
ルラシステムであり、移動機が複数の基地局とソフトハ
ンドオーバーを行うセルラシステムであり、 前記移動機は、 前記ソフトハンドオーバー状態にある複数の基地局から
の下り信号の受信品質をモニタする下り受信品質モニタ
手段と、 前記複数の下り受信品質モニタ結果に従って送信すべき
基地局を指示する信号を送出する基地局指定手段と、 前記基地局指定信号を上り信号に多重化して前記複数の
基地局に送信する多重化手段と、 前記ハンドオーバー状態にある複数の基地局からの受信
信号を合成受信する受信手段とを含み、 前記基地局は、 前記上り信号に多重化された基地局指定信号を復調する
復調手段と、 前記復調された基地局指定信号に従って、該当する移動
機への下り送信信号の送信を制御する送信制御手段とを
含むセルラシステム。1. A cellular system using a direct spreading code division multiple access system, wherein a mobile station performs a soft handover with a plurality of base stations, wherein the mobile station is in the soft handover state. Downlink reception quality monitoring means for monitoring reception quality of downlink signals from a plurality of base stations; base station designation means for transmitting a signal indicating a base station to be transmitted according to the plurality of downlink reception quality monitoring results; A multiplexing unit that multiplexes a station designation signal into an uplink signal and transmits the multiplexed signal to the plurality of base stations; and a receiving unit that combines and receives reception signals from the plurality of base stations in the handover state. A demodulating means for demodulating a base station designating signal multiplexed with the uplink signal, and a demodulator for a corresponding mobile station according to the demodulated base station designating signal. Cellular system and a transmission control means for controlling the transmission of the transmission signal.
前記基地局のそれぞれからすべての移動機に対して常時
送信されるパイロットチャネルを用いて受信品質を測定
することを特徴とする請求項１記載のセルラシステム。2. The downlink reception quality monitoring means of the mobile device,
The cellular system according to claim 1, wherein the reception quality is measured using a pilot channel that is constantly transmitted from each of the base stations to all mobile stations.
信号が自基地局では無い場合に送信を停止する請求項１
記載のセルラシステム。3. The transmission control means of the base station stops transmission when the base station designation signal is not the own base station.
The cellular system as described.
信号が自基地局の場合および基地局指定信号に伝送誤り
を検出した場合に送信を行う請求項３に記載のセルラシ
ステム。4. The cellular system according to claim 3, wherein the transmission control means of the base station performs transmission when the base station designating signal is the base station designation and when a transmission error is detected in the base station designating signal.
地局の下り受信品質の差があらかじめ決められた値より
小さい場合に、複数の基地局を指定することを特徴とす
る請求項１に記載のセルラシステム。5. The base station designating means of the mobile station designates a plurality of base stations when a difference between downlink reception qualities of the plurality of base stations is smaller than a predetermined value. 2. The cellular system according to 1.
基地局の下り受信品質があらかじめ決められた値より小
さい場合に、複数の基地局を指定することを特徴とする
請求項１に記載のセルラシステム。6. The mobile station according to claim 1, wherein said base station designating means designates a plurality of base stations when the downlink reception quality of all base stations is smaller than a predetermined value. The cellular system as described.
ルラシステムであり、移動機が複数の基地局とソフトハ
ンドオーバーを行うセルラシステムに用いられる移動機
であり、 前記ソフトハンドオーバー状態にある複数の基地局から
の下り信号の受信品質をモニタする下り受信品質モニタ
手段と、 前記複数の下り受信品質モニタ結果に従って送信すべき
基地局を指示する信号を送出する基地局指定手段と、 前記基地局指定信号を上り信号に多重化して前記複数の
基地局に送信する多重化手段と、 前記ハンドオーバー状態にある複数の基地局からの受信
信号を合成受信する受信手段とを含む移動機。7. A cellular system using a direct spreading code division multiple access system, wherein the mobile device is used in a cellular system performing soft handover with a plurality of base stations, and is in the soft handover state. Downlink reception quality monitoring means for monitoring reception quality of downlink signals from a plurality of base stations; base station designation means for transmitting a signal indicating a base station to be transmitted according to the plurality of downlink reception quality monitoring results; A mobile station comprising: multiplexing means for multiplexing a station designation signal into an uplink signal and transmitting the multiplexed signal to the plurality of base stations; and receiving means for combining and receiving signals received from the plurality of base stations in the handover state.
前記基地局のそれぞれからすべての移動機に対して常時
送信されるパイロットチャネルを用いて受信品質を測定
することを特徴とする請求項７記載の移動機。8. The downlink reception quality monitoring means of the mobile device,
The mobile station according to claim 7, wherein the reception quality is measured using a pilot channel constantly transmitted from each of the base stations to all mobile stations.
信号が自基地局では無い場合に送信を停止する請求項７
記載の移動機。9. The transmission control means of the base station stops transmission when the base station designation signal is not the own base station.
Mobile device as described.
定信号が自基地局の場合および基地局指定信号に伝送誤
りを検出した場合に送信を行う請求項９に記載の移動
機。10. The mobile station according to claim 9, wherein the transmission control means of the base station performs transmission when the base station designating signal is the own base station and when a transmission error is detected in the base station designating signal.
基地局の下り受信品質の中で最良品質を示す基地局とこ
の最良品質との差があらかじめ決められた値より小さい
基地局を指定することを特徴とする請求項７に記載の移
動機。11. The base station designating means of the mobile station selects a base station exhibiting the best quality among downlink reception qualities of a plurality of base stations and a base station whose difference between the best quality is smaller than a predetermined value. The mobile device according to claim 7, wherein the mobile device is designated.
の基地局の下り受信品質があらかじめ決められた値より
小さい場合に、複数の基地局を指定することを特徴とす
る請求項７に記載の移動機。12. The mobile station according to claim 7, wherein said base station designating means designates a plurality of base stations when downlink reception qualities of all base stations are smaller than a predetermined value. Mobile device as described.
セルラシステムであり、移動機が複数の基地局とソフト
ハンドオーバーを行うセルラシステムに用いられる基地
局であり、 前記移動機からの上り信号に多重化された基地局指定信
号を復調する復調手段と、 前記復調された基地局指定信号に従って、該当する移動
機への下り送信信号の送信を制御する送信制御手段とを
含む基地局。13. A cellular system using a direct spreading code division multiple access system, wherein the mobile station is a base station used in a cellular system performing soft handover with a plurality of base stations, and an uplink signal from the mobile station. A base station comprising: a demodulation unit that demodulates a base station designation signal multiplexed into the base station; and a transmission control unit that controls transmission of a downlink transmission signal to a corresponding mobile station in accordance with the demodulated base station designation signal.
定信号が自基地局では無い場合に送信を停止する請求項
１３記載の基地局。14. The base station according to claim 13, wherein said transmission control means of said base station stops transmission when the base station designating signal is not its own base station.
定信号が自基地局の場合および基地局指定信号に伝送誤
りを検出した場合に送信を行う請求項１４に記載の基地
局。15. The base station according to claim 14, wherein the transmission control means of the base station performs transmission when the base station designating signal is the own base station and when a transmission error is detected in the base station designating signal.
セルラシステムであり、移動機が複数の基地局とソフト
ハンドオーバーを行うセルラシステムであり、 前記移動機は、 前記ソフトハンドオーバー状態にある複数の基地局から
の下り信号の受信品質をモニタし、モニター結果とそれ
に対応する基地局を示す信号とからなる副信号を出力す
る受信品質モニタ手段と、 前記副信号を上り信号に多重化して前記複数の基地局に
送信する多重化手段と、 前記ハンドオーバー状態にある複数の基地局からの受信
信号を合成受信する受信手段とを含み、 前記基地局は、 前記上り信号に多重化された副信号を復調する復調手段
と、 前記復調された副信号に従って、自局の下り信号の送信
を停止するか否かを示す送信停止信号を生成する送信停
止信号生成手段と、 前記送信停止信号が送信停止を示しているときは、移動
機への下り送信信号の送信を停止する送信制御手段とを
含むセルラシステム。16. A cellular system using a direct spreading code division multiple access system, wherein a mobile station performs soft handover with a plurality of base stations, wherein the mobile station is in the soft handover state. A reception quality monitoring unit that monitors reception quality of downlink signals from a plurality of base stations and outputs a sub signal including a monitoring result and a signal indicating the corresponding base station, and multiplexes the sub signal into an uplink signal. Multiplexing means for transmitting to the plurality of base stations, and receiving means for combining and receiving signals received from the plurality of base stations in the handover state, wherein the base station is multiplexed with the uplink signal. Demodulation means for demodulating a sub-signal; a transmission stop signal for generating a transmission stop signal indicating whether to stop transmission of a downlink signal of the own station according to the demodulated sub signal. A cellular system comprising: generating means; and transmission control means for stopping transmission of a downlink transmission signal to a mobile device when the transmission stop signal indicates transmission stop.
記基地局のそれぞれからすべての移動機に対して常時送
信されるパイロットチャネルを用いて受信品質を測定す
ることを特徴とする請求項１６記載のセルラシステム。17. The reception quality monitoring means of the mobile station measures the reception quality using a pilot channel constantly transmitted from each of the base stations to all the mobile stations. The cellular system as described.
号に誤りが検出されたときは、前記下り信号の送信を停
止しない請求項１６に記載のセルラシステム。18. The cellular system according to claim 16, wherein said transmission control means of said base station does not stop transmission of said downlink signal when an error is detected in said sub-signal.
基地局の下り受信品質があらかじめ決められた値より小
さい場合には、自局の下り信号品質が所定の順位以上で
あるときには、前記送信停止信号を出力しないことを特
徴とする請求項１６に記載のセルラシステム。19. The transmission stop signal generating means, if the downlink reception quality of all base stations is smaller than a predetermined value, and if the downlink signal quality of the own station is higher than a predetermined order, the transmission stop signal generation means. 17. The cellular system according to claim 16, wherein a stop signal is not output.
セルラシステムであり、移動機が複数の基地局とソフト
ハンドオーバーを行うセルラシステムに用いられる移動
機であり、 前記ソフトハンドオーバー状態にある複数の基地局から
の下り信号の受信品質をモニタし、モニター結果とそれ
に対応する基地局を示す信号とからなる副信号を出力す
る受信品質モニタ手段と、 前記副信号を上り信号に多重化して前記複数の基地局に
送信する多重化手段と、 前記ハンドオーバー状態にある複数の基地局からの受信
信号を合成受信する受信手段とを含む移動機。20. A cellular system using a direct spreading code division multiple access system, wherein the mobile device is used in a cellular system performing soft handover with a plurality of base stations, and is in the soft handover state. A reception quality monitoring unit that monitors reception quality of downlink signals from a plurality of base stations and outputs a sub signal including a monitoring result and a signal indicating the corresponding base station, and multiplexes the sub signal into an uplink signal. A mobile station comprising: multiplexing means for transmitting to the plurality of base stations; and receiving means for combining and receiving signals received from the plurality of base stations in the handover state.
記基地局のそれぞれからすべての移動機に対して常時送
信されるパイロットチャネルを用いて受信品質を測定す
ることを特徴とする請求項２０記載の移動機。21. The reception quality monitoring means of the mobile station measures reception quality using a pilot channel which is constantly transmitted from each of the base stations to all mobile stations. Mobile device as described.
セルラシステムであり、移動機が複数の基地局とソフト
ハンドオーバーを行うセルラシステムに用いられる基地
局であり、移動機からの上り信号にその移動機とソフト
ハンドオーバー状態にある複数の基地局からの下り信号
の受信品質のモニタ結果とそれに対応する基地局を示す
信号とからなる副信号とが多重化された上り信号を受信
する基地局であり、 前記副信号を復調する復調手段と、 前記復調された副信号に従って、自局の下り信号の送信
を停止するか否かを示す送信停止信号を生成する送信停
止信号生成手段と、 前記送信停止信号が送信停止を示しているときは、移動
機への下り送信信号の送信を停止する送信制御手段とを
含む基地局。22. A cellular system using a direct spreading code division multiple access system, wherein the mobile station is a base station used in a cellular system performing soft handover with a plurality of base stations, and the mobile station transmits an uplink signal from the mobile station. A base station for receiving an uplink signal in which a result of monitoring reception quality of downlink signals from a plurality of base stations in a soft handover state with the mobile device and a sub-signal composed of a signal indicating the corresponding base station are multiplexed. A station, a demodulation means for demodulating the sub-signal, and a transmission stop signal generating means for generating a transmission stop signal indicating whether to stop transmitting the downlink signal of the own station according to the demodulated sub-signal, A transmission control unit for stopping transmission of the downlink transmission signal to the mobile station when the transmission stop signal indicates transmission stop.
が検出されたときは、前記下り信号の送信を停止しない
請求項２２に記載の基地局。23. The base station according to claim 22, wherein said transmission control means does not stop transmission of said downlink signal when an error is detected in said sub-signal.
基地局の下り受信品質があらかじめ決められた値より小
さい場合には、自局の下り信号品質が所定の順位以上で
あるときには、前記送信停止信号を出力しないことを特
徴とする請求項２３に記載の基地局。24. The transmission stop signal generating means, if the downlink reception quality of all base stations is smaller than a predetermined value, and if the downlink signal quality of the own station is higher than a predetermined order, the transmission stop signal generation means. The base station according to claim 23, wherein the base station does not output a stop signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15308998A JP2991185B2 (en) | 1997-06-09 | 1998-06-02 | Cellular communication system, and mobile station and base station used therein |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9-151072 | 1997-06-09 | ||
| JP15107297 | 1997-06-09 | ||
| JP15308998A JP2991185B2 (en) | 1997-06-09 | 1998-06-02 | Cellular communication system, and mobile station and base station used therein |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1169416A true JPH1169416A (en) | 1999-03-09 |
| JP2991185B2 JP2991185B2 (en) | 1999-12-20 |
Family
ID=26480447
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15308998A Expired - Lifetime JP2991185B2 (en) | 1997-06-09 | 1998-06-02 | Cellular communication system, and mobile station and base station used therein |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2991185B2 (en) |
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