JP2546897B2 - Interference detection method for mobile station initiated handoff system - Google Patents
Interference detection method for mobile station initiated handoff systemInfo
- Publication number
- JP2546897B2 JP2546897B2 JP1157701A JP15770189A JP2546897B2 JP 2546897 B2 JP2546897 B2 JP 2546897B2 JP 1157701 A JP1157701 A JP 1157701A JP 15770189 A JP15770189 A JP 15770189A JP 2546897 B2 JP2546897 B2 JP 2546897B2
- Authority
- JP
- Japan
- Prior art keywords
- station
- radio base
- mobile station
- signal
- control
- 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.)
- Expired - Fee Related
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- Mobile Radio Communication Systems (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は無線局と移動局との間でデジタル信号を送受
信するデジタル通信に使用される移動局主導ハンドオフ
システムの干渉検出方式に関するものである。The present invention relates to an interference detection method for a mobile station-initiated handoff system used for digital communication for transmitting and receiving digital signals between a wireless station and a mobile station. .
従来のこの種の移動局主導ハンドオフシステムは、１
つの制御局に複数の無線基地局を収容し、各無線基地局
は移動局との間で制御チャンネル信号及び音声チャンネ
ル信号をそれぞれ対応する周波数の回線を通して送受信
する。移動局が各無線基地局からの下り信号の受信電界
強度を判定し通信に最適な無線基地局を選択し無線基地
局間の切り替え要求を示すハンドオフ要求を前記制御局
へ通知すると、制御局は移動局の回線接続先が選択され
た無線基地局になるように周波数の変更制御を行なう
（特開昭64−55924号公報参照）。このようにして移動
局と移動局により選択された無線基地局とが回線接続さ
れた後、その回線が干渉波により障害を受けているかど
うかを検出するために、移動局で無線基地局からの下り
信号のみに対して干渉検出を行なっている。移動局で干
渉波を検出すると無線基地局を介して干渉波検出信号を
制御局に通知する。干渉検出信号を受信した制御局は、
干渉を検出した周波数と異る周波数を移動局及び無線基
地局間の回線に割り当て自局内ハンドオフを行なう。こ
の結果、下り信号の干渉を回避することができる。This type of conventional mobile station-initiated handoff system is
One control station accommodates a plurality of radio base stations, and each radio base station transmits / receives a control channel signal and a voice channel signal to / from a mobile station through lines of corresponding frequencies. When the mobile station notifies the control station of the handoff request indicating the request for switching between the radio base stations by selecting the radio base station optimal for communication by determining the received electric field strength of the downlink signal from each radio base station, the control station Frequency change control is performed so that the line connection destination of the mobile station becomes the selected wireless base station (see Japanese Patent Laid-Open No. 64-55924). After the mobile station and the radio base station selected by the mobile station are connected to each other in this way, in order to detect whether the line is damaged by an interference wave, Interference detection is performed only on the downlink signal. When the mobile station detects the interference wave, it notifies the control station of the interference wave detection signal via the radio base station. The control station that received the interference detection signal
A frequency different from the frequency at which the interference is detected is assigned to the line between the mobile station and the radio base station to perform the handoff in the own station. As a result, downlink signal interference can be avoided.
上述した従来の移動局主導ハンドオフシステムの干渉
検出方式では、上り信号の干渉検出を行なっていないた
め、上り信号にて干渉波による障害が生じても検出する
ことができず、制御チャンネルにおいては上り情報であ
る発呼要求信号，着呼応答信号等が正確に制御局に伝送
されず、又通話チャンネルにおいては音声信号が正確に
伝送されないため、呼処理制御や音声品質に悪影響を及
ぼす欠点がある。In the interference detection method of the conventional mobile station-initiated handoff system described above, interference detection of the uplink signal is not performed, so even if a failure due to an interference wave occurs in the uplink signal, it cannot be detected, and the uplink is not detected in the control channel. Information such as a call request signal and an incoming call response signal are not accurately transmitted to the control station, and the voice signal is not accurately transmitted in the communication channel, which has a drawback of adversely affecting call processing control and voice quality. .
本発明の移動局主導ハンドオフシステムの干渉検出方
式は、１つの制御局に移動局との間で前記制御局からの
制御チャンネル信号及び音声チャンネル信号をそれぞれ
対応する周波数の回線を通して送受信する複数の無線基
地局を収容し、前記移動局が前記各無線基地局からの下
り信号の受信状況に基づいて通信に最適な無線基地局を
選択し無線基地局間の切り替え要求を示すハンドオフ要
求を前記制御局へ通知することにより前記移動局の回線
接続先を選択された無線基地局に変更する移動局主導ハ
ンドオフを行うデジタル移動通信システムにおいて、 前記各無線基地局に、回線接続された前記移動局から
の上り信号の受信信号品質を監視し、劣化を検出すると
前記移動局からの前記ハンドオフ要求の有無に応じて劣
化の原因が干渉波によるものか判定し、干渉波による場
合は自無線基地局対応の他の周波数への切り替え要求を
示す自局内ハンドオフ要求を前記制御局へ通知する手段
を備え、 前記制御局に、前記各無線基地局から前記自局内ハン
ドオフ要求を受けると当該無線基地局及び前記移動局に
対し回線接続用周波数を当該無線基地局対応の他の周波
数に変更させる手段を備えている。An interference detection method for a mobile station-initiated handoff system according to the present invention comprises a plurality of radios for transmitting and receiving a control channel signal and a voice channel signal from the control station to and from a mobile station through a line of corresponding frequency. A base station is accommodated, the mobile station selects a wireless base station most suitable for communication based on a reception condition of a downlink signal from each of the wireless base stations, and issues a handoff request indicating a switching request between the wireless base stations to the control station. In a digital mobile communication system that performs a mobile station-initiated handoff that changes the circuit connection destination of the mobile station to the selected radio base station by notifying the When the deterioration is detected by monitoring the received signal quality of the upstream signal, the cause of the deterioration is the interference wave depending on the presence or absence of the handoff request from the mobile station. It is provided with means for notifying the control station of a handoff request within the own station indicating a request to switch to another frequency corresponding to its own radio base station if it is due to an interference wave, to the control station, each radio base station And a means for changing the line connection frequency to another frequency corresponding to the radio base station when the intra-station handoff request is received from the radio base station and the mobile station.
〔実施例〕 第１図は本発明の一実施例の系統図である。制御局10
0は、呼処理制御時に交換局10と、制御線150−４を介し
て制御信号の送受信を行なう。無線基地局200−１、200
−２および200−３はそれぞれ、移動局50と制御信号や
音声信号の送受信を行なっている。制御線150−１、150
−２、150−３は、制御局100と各無線基地局200−１、2
00−２、200−３との制御信号の送受信をするための制
御線である。参照番号250−１、250−２、250−３は各
無線基地局200−１、200−２、200−３のサービスエリ
アを示す。[Embodiment] FIG. 1 is a system diagram of an embodiment of the present invention. Control station 10
0 transmits / receives a control signal to / from switching center 10 via control line 150-4 during call processing control. Radio base stations 200-1, 200
-2 and 200-3 transmit and receive control signals and voice signals to and from the mobile station 50, respectively. Control lines 150-1, 150
-2, 150-3 are the control station 100 and the respective radio base stations 200-1, 2
A control line for transmitting and receiving control signals to and from 00-2 and 200-3. Reference numerals 250-1, 250-2 and 250-3 indicate service areas of the respective radio base stations 200-1, 200-2 and 200-3.
第２図は本実施例の各無線基地局200−１、200−２、
200−３で信号品質判定するためのヴィタビ復号器を用
いた受信系を示すブロック図である。例えば移動局50の
通話中に上り信号の干渉検出を行なう時には、移動局50
の上り信号を無線基地局200−１のアンテナ300にて受信
し、波器301を経て受信機302にて復調して、ヘッダ検
出器303に入力する。ヘッダ検出器303は、信号のヘッダ
を検出するとバッファ306をリセットし最大値に設定す
る。最大値とは、比較器305及びバッファ306のビット数
によって決まる。例えば、ビット数が４ビットの場合は
15（10進法）となる。この最大値は、ヴィタビ復号器30
4から出力されるパスメトリック値の最大値と最小値と
の差と比較して大きければ、いかなる値をとってもかま
わない。その後信号はヴィタビ復号器304にて復号され
信号制御器307に入力される。更にウィタビ復号器304に
て復号される時、信号品質と相関のあるパスメトリック
値の最大値と最小値との差を比較器305の一端に入力
し、バッファ306の値と比較して小さい方の値を出力
し、信号制御器307およびバッファ306に送る。この動作
を、受信したデジタル信号の復号が終了するまで繰り返
し行なうことにより、パスメトリック値の最大値と最小
値との差の最小値を求めることができ、これが信号制御
器307に入力される。パスメトリック値の最大値と最小
値との差の最小値は、信号品質と相関関係にあり、信号
制御器307はパスメトリックの差により信号品質を求め
る。FIG. 2 shows each of the wireless base stations 200-1, 200-2 of this embodiment.
It is a block diagram which shows the receiving system which used the Viterbi decoder for signal quality determination in 200-3. For example, when detecting an interference of an up signal during a call of the mobile station 50, the mobile station 50
The uplink signal is received by the antenna 300 of the radio base station 200-1, demodulated by the receiver 302 via the wave device 301, and input to the header detector 303. When the header detector 303 detects the header of the signal, it resets the buffer 306 and sets it to the maximum value. The maximum value depends on the number of bits of the comparator 305 and the buffer 306. For example, if the number of bits is 4 bits
It becomes 15 (decimal). This maximum value is for Viterbi decoder 30
Any value may be used as long as it is larger than the difference between the maximum value and the minimum value of the path metric value output from 4. After that, the signal is decoded by the Viterbi decoder 304 and input to the signal controller 307. Further, when it is decoded by the Viterbi decoder 304, the difference between the maximum value and the minimum value of the path metric value that is correlated with the signal quality is input to one end of the comparator 305, which is smaller than the value in the buffer 306. The value of is output and sent to the signal controller 307 and the buffer 306. By repeating this operation until the decoding of the received digital signal is completed, the minimum value of the difference between the maximum value and the minimum value of the path metric value can be obtained, and this is input to the signal controller 307. The minimum value of the difference between the maximum value and the minimum value of the path metric value is correlated with the signal quality, and the signal controller 307 obtains the signal quality from the difference of the path metric.
もし信号品質が許容限度よりも劣化している時、信号
制御器307は、移動局50からの受信信号（上り信号）の
信号品質の劣化が受信電界強度の衰弱によるものなの
か、あるいは、干渉波によるものなのかを判断する。こ
の判断は、移動局50からの下り信号の受信電界強度の衰
弱によるハンドオフ要求信号の有無により行なう。例え
ば、上り信号の信号品質劣化を検出したと同時に移動局
50から受信電界強度の衰弱によるハンドオフ要求信号を
受信した場合は、移動局50が無線基地局200−１のサー
ビスエリア250−１の境界あたりで通信していることが
推定され、上り信号でも同様に受信電界強度の衰弱が発
生する。この場合、無線基地局200−１では、信号品質
劣化の原因を受信電界強度が弱くなったためであると判
断し、従来と同様の処理のみ行ない移動局50からのハン
ドオフ要求信号を制御局100に転送する。これにより無
線基地局が切り替えられる。一方、上り信号の信号品質
劣化を検出した時に移動局50から受信電界強度の衰弱に
よるハンドオフ要求信号を受信していない場合は、電波
伝搬のロスによる信号品質劣化ではないので、上り信号
の回線に使用されている周波数に対して干渉波が発生し
ていると判断し、信号制御器307は無線基地局200−１で
使用できる他の周波数への変更を要求する信号、つまり
自局内ハンドオフ要求信号を制御局100に報告する。そ
の後制御局100により自局内ハンドオフ要求信号を交換
局10に報告し、交換局10では無線基地局200−１の使用
できる他の周波数の回線を設定する。そして交換局10か
ら自局内ハンドオフ命令信号を制御局100、無線基地局2
00−１を介し移動局50に報告し、移動局50は自局内ハン
ドオフ命令信号に含まれる周波数に切り替り、自局内ハ
ンドオフを完了する。If the signal quality deteriorates below the allowable limit, the signal controller 307 determines whether the deterioration of the signal quality of the reception signal (uplink signal) from the mobile station 50 is due to the weakening of the reception electric field strength or interference. Determine if it was due to waves. This determination is made based on the presence or absence of the handoff request signal due to the weakening of the received electric field strength of the downlink signal from the mobile station 50. For example, when the mobile station detects the deterioration of the signal quality of the uplink signal,
When the handoff request signal due to the weakening of the received electric field strength is received from 50, it is estimated that the mobile station 50 is communicating around the boundary of the service area 250-1 of the wireless base station 200-1, and the same applies to the uplink signal. The received electric field strength weakens. In this case, in the wireless base station 200-1, it is determined that the cause of the signal quality deterioration is that the received electric field strength is weakened, and the handoff request signal from the mobile station 50 is performed to the control station 100 by performing only the same processing as the conventional one. Forward. As a result, the wireless base station is switched. On the other hand, if the handoff request signal due to the weakening of the received electric field strength is not received from the mobile station 50 when the deterioration of the signal quality of the upstream signal is detected, it is not the signal quality deterioration due to the loss of the radio wave propagation, and therefore the signal of the upstream signal is not transmitted to the line. The signal controller 307 determines that an interference wave is generated with respect to the frequency being used, and the signal controller 307 is a signal requesting a change to another frequency that can be used by the radio base station 200-1, that is, a handoff request signal within the own station. To the control station 100. After that, the control station 100 reports a handoff request signal within itself to the exchange station 10, and the exchange station 10 sets a line of another frequency that can be used by the radio base station 200-1. Then, the exchange station 10 sends a local handoff command signal to the control station 100 and the wireless base station 2.
After reporting to the mobile station 50 via 00-1, the mobile station 50 switches to the frequency included in the in-station handoff command signal and completes the in-station handoff.
以上説明したように本発明は、下り信号の受信状況に
基づく移動局の主導により選択されある周波数を用いて
回線接続された無線基地局にて移動局からの上り信号の
信号品質を監視し、劣化を検出すると移動局からのハン
ドオフ要求の有無に応じて劣化の原因が干渉波（外来
波）によるものか判定し、干渉波による場合は自局内ハ
ンドオフ要求を制御局へ通知することにより、無線基地
局及び移動局間の回線接続用周波数を当該無線基地局対
応の他の周波数に変更させるので、従来方式では知り得
なかった上り信号の外来波による干渉を検出することが
でき、外来波による呼処理制御の妨害や通話品質の劣化
を防げる効果がある。As described above, the present invention monitors the signal quality of the uplink signal from the mobile station in the radio base station line-connected using a certain frequency selected by the initiative of the mobile station based on the reception status of the downlink signal, When deterioration is detected, it is determined whether the cause of the deterioration is due to an interference wave (external wave) according to the presence / absence of a handoff request from the mobile station. Since the frequency for line connection between the base station and the mobile station is changed to another frequency compatible with the radio base station, it is possible to detect the interference due to the external wave of the upstream signal, which cannot be known by the conventional method, and it is possible to detect the external wave. This has the effect of preventing interference with call processing control and deterioration of call quality.
第１図は本発明の実施例の系統図、第２図は本発明の実
施例のブロック図である。 10……交換局、50……移動局、100……制御局、150−
１、150−２、150−３、150−４……制御線、200−１、
200−２、200−３……無線基地局、250−１、250−２、
250−３……サービスエリア、300……アンテナ、301…
…波器、302……受信機、303……ヘッダ検出器、304
……ヴィタビ復号器、305……比較器、306……バッフ
ァ、307……信号制御器。FIG. 1 is a system diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention. 10 ... Exchange station, 50 ... Mobile station, 100 ... Control station, 150-
1, 150-2, 150-3, 150-4 ... Control line, 200-1,
200-2, 200-3 ... radio base stations, 250-1, 250-2,
250-3 ... Service area, 300 ... Antenna, 301 ...
… Wave device, 302… Receiver, 303… Header detector, 304
... Viterbi decoder, 305 ... comparator, 306 ... buffer, 307 ... signal controller.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭64−12628（ＪＰ，Ａ) 特開 昭64−55924（ＪＰ，Ａ) 特開 昭63−245025（ＪＰ，Ａ) 特開 昭58−137337（ＪＰ，Ａ) 特開 平２−241249（ＪＰ，Ａ) 特開 平２−215236（ＪＰ，Ａ) 特開 平２−69026（ＪＰ，Ａ) 特開 昭63−180229（ＪＰ，Ａ) 特開 昭57−17246（ＪＰ，Ａ) 特開 昭60−226232（ＪＰ，Ａ) 特開 昭60−33750（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 64-12628 (JP, A) JP-A 64-55924 (JP, A) JP-A 63-245025 (JP, A) JP-A 58- 137337 (JP, A) JP-A-2-241249 (JP, A) JP-A-2-215236 (JP, A) JP-A-2-69026 (JP, A) JP-A-63-180229 (JP, A) JP-A-57-17246 (JP, A) JP-A-60-226232 (JP, A) JP-A-60-33750 (JP, A)
Claims (1)
からの制御チャンネル信号及び音声チャンネル信号をそ
れぞれ対応する周波数の回線を通して送受信する複数の
無線基地局を収容し、前記移動局が前記各無線基地局か
らの下り信号の受信状況に基づいて通信に最適な無線基
地局を選択し無線基地局間の切り替え要求を示すハンド
オフ要求を前記制御局へ通知することにより前記移動局
の回線接続先を選択された無線基地局に変更する移動局
主導ハンドオフを行うデジタル移動通信システムにおい
て、 前記各無線基地局に、回線接続された前記移動局からの
上り信号の受信信号品質を監視し、劣化を検出すると前
記移動局からの前記ハンドオフ要求の有無に応じて劣化
の原因が干渉波によるものか判定し、干渉波による場合
は自無線基地局対応の他の周波数への切り替え要求を示
す自局内ハンドオフ要求を前記制御局へ通知する手段を
備え、 前記制御局に、前記各無線基地局から前記自局内ハンド
オフ要求を受けると当該無線基地局及び前記移動局に対
し回線接続用周波数を当該無線基地局対応の他の周波数
に変更させる手段を備えたことを特徴とする移動局主導
ハンドオフシステムの干渉検出方式。1. A mobile station that accommodates a plurality of radio base stations for transmitting and receiving a control channel signal and a voice channel signal from the control station to and from a mobile station in one control station. Of the mobile station by notifying the control station of a handoff request indicating a request for switching between radio base stations by selecting the optimum radio base station for communication based on the reception status of the downlink signal from each of the radio base stations. In a digital mobile communication system that performs a mobile station-initiated handoff to change a line connection destination to a selected radio base station, each radio base station monitors the received signal quality of an upstream signal from the line-connected mobile station. When deterioration is detected, it is determined whether the cause of the deterioration is an interference wave according to the presence or absence of the handoff request from the mobile station. A station is provided with means for notifying the control station of an in-station handoff request indicating a request to switch to another frequency corresponding to the station, and the control station receives the in-station handoff request from each of the radio base stations, and the radio base station concerned. And an interference detection method for a mobile station-initiated handoff system, comprising means for changing the line connection frequency of the mobile station to another frequency corresponding to the radio base station.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1157701A JP2546897B2 (en) | 1989-06-19 | 1989-06-19 | Interference detection method for mobile station initiated handoff system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1157701A JP2546897B2 (en) | 1989-06-19 | 1989-06-19 | Interference detection method for mobile station initiated handoff system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0322636A JPH0322636A (en) | 1991-01-31 |
| JP2546897B2 true JP2546897B2 (en) | 1996-10-23 |
Family
ID=15655490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1157701A Expired - Fee Related JP2546897B2 (en) | 1989-06-19 | 1989-06-19 | Interference detection method for mobile station initiated handoff system |
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| Country | Link |
|---|---|
| JP (1) | JP2546897B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58137337A (en) * | 1982-02-10 | 1983-08-15 | Nippon Telegr & Teleph Corp <Ntt> | Interference detection system |
| JP2558684B2 (en) * | 1987-03-31 | 1996-11-27 | 日本電信電話株式会社 | Mobile radio channel control system |
| JPS6412628A (en) * | 1987-07-06 | 1989-01-17 | Nippon Telegraph & Telephone | Time division multiplex mobile communication system |
| JPS6455924A (en) * | 1987-08-26 | 1989-03-02 | Nec Corp | Digital mobile communication system and mobile terminal equipment |
-
1989
- 1989-06-19 JP JP1157701A patent/JP2546897B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0322636A (en) | 1991-01-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |