JP2883965B2

JP2883965B2 - CDMA mobile communication method, system and mobile station device

Info

Publication number: JP2883965B2
Application number: JP8536371A
Authority: JP
Inventors: 文幸安達
Original assignee: エヌ・ティ・ティ移動通信網株式会社
Priority date: 1995-05-31
Filing date: 1996-05-30
Publication date: 1999-04-19
Anticipated expiration: 2016-05-30

Description

【発明の詳細な説明】技術分野本発明は、セルラ移動通信における受信レベル監視お
よびハンドオフに関するものである。Description: TECHNICAL FIELD The present invention relates to reception level monitoring and handoff in cellular mobile communication.

背景技術セルラ移動通信では、広いサービスエリアに多数の基
地局を配置している。そして、移動局が最も通信品質の
よい基地局と通信を行うことができるように、移動局の
移動につれて接続する基地局を次々と切り替えて、通信
を継続する。この場合、次に接続する基地局を探索する
ために、移動局において、通信中基地局の周辺基地局の
電波を受信し受信レベルを測定している。その測定結果
から、移動局は、最も高いレベルの周辺基地局を次に接
続すべき新基地局と判定し、通信中の基地局に通知す
る。このようにすれば、基地局の切り替え（ハンドオ
フ）が必要になったときには、通信中の基地局の上位局
は、通信中基地局および新基地局に対してハンドオフの
開始を指示する。ハンドオフ中には、通信中基地局およ
び新基地局から同一送信データを送信し、移動局は、送
受信周波数を通信中基地局からの新基地局へ、あるいは
その逆に、交互に切り替える。これが、セルラ移動通信
における周辺基地局監視およびハンドオフの方法であ
る。BACKGROUND ART In cellular mobile communication, a large number of base stations are arranged in a wide service area. Then, as the mobile station moves, the connected base stations are switched one after another so that the mobile station can communicate with the base station having the best communication quality, and the communication is continued. In this case, in order to search for a base station to be connected next, the mobile station receives radio waves from base stations in the vicinity of the communicating base station and measures the reception level. From the measurement result, the mobile station determines that the peripheral base station with the highest level is the new base station to be connected next, and notifies the base station in communication. In this way, when the base station needs to be switched (handoff), the upper station of the communicating base station instructs the communicating base station and the new base station to start handoff. During handoff, the same transmission data is transmitted from the communicating base station and the new base station, and the mobile station alternately switches the transmission / reception frequency from the communicating base station to the new base station or vice versa. This is a method of monitoring and handing off peripheral base stations in cellular mobile communication.

ところで、時分割多元接続方式（TDMA）では、送信時
間をスロットという短い時間に区切り、多数の移動局が
異なるスロットを割り当てられ、送信および受信を周期
的に行っている。このため、移動局の送信および受信ス
ロット以外の時間は空き時間である。この空き時間を用
いて、移動局は周辺基地局監視を行い、最大受信レベル
となる基地局を容易に選択することができる。このよう
にして選択した新基地局にハンドオフする（“デジタル
方式自動車電話システム”標準規格、RCR STD−27B、財
団法人電波システム開発センター、または“Personal d
igital cellular telecommunication system RCR stand
ard,RCR STD−27",Research＆Development Center for
Radio Systemを参照）。By the way, in the time division multiple access system (TDMA), the transmission time is divided into short time slots, and a large number of mobile stations are assigned different slots, and perform transmission and reception periodically. Therefore, the time other than the transmission and reception slots of the mobile station is a free time. Using this idle time, the mobile station monitors the surrounding base stations and can easily select the base station having the maximum reception level. Handoff to the new base station selected in this way (“Digital Car Phone System” standard, RCR STD-27B, Radio System Development Center, or “Personal d
igital cellular telecommunication system RCR stand
ard, RCR STD-27 ", Research & Development Center for
Radio System).

一方、符号分割多元接続方式（CDMA）では、TDMAのよ
うな空き時間がないが、全ての基地局で同一の無線周波
数を用いることができるため、通信中に周辺基地局監視
やハンドオフ時に送受信周波数を切り替える必要がない
（R.Padovani,“Reverse link performance of IS−95
based cellular systems,"IEEE Personal Communicatio
ns,vol.1,pp.28−34,3rd Quarter1994参照）。すなわ
ち、CDMAでは、各基地局は同じ周波数で、異なる拡散符
号系列を用いて送信データを広帯域信号へと拡散してい
る。このため、受信側では、周辺基地局の拡散符号系列
で受信信号を逆拡散する相関器をもう一個、周辺基地局
監視用とハンドオフ用に持てばよい。On the other hand, in Code Division Multiple Access (CDMA), there is no idle time like TDMA, but the same radio frequency can be used by all base stations. (R. Padovani, “Reverse link performance of IS-95
based cellular systems, "IEEE Personal Communicatio
ns, vol. 1, pp. 28-34, 3rd Quarter 1994). That is, in CDMA, each base station spreads transmission data into a wideband signal using different spreading code sequences at the same frequency. Therefore, the receiving side may have another correlator for despreading the received signal with the spreading code sequence of the peripheral base station, for monitoring the peripheral base station and for handoff.

しかし、CDMAにおいても、基地局同士が同一無線周波
数を用いることができない場合もある。これは例えば、
通信範囲が狭いマイクロセル基地局にオーバレイされた
通信範囲が広いマクロセル基地局の場合である。マイク
ロセル基地局の送信電力はマイクロセル基地局の送信電
力より小さいために、もし、同一の無線周波数を用いる
と、マイクロセル基地局の送信信号はマイクロセル基地
局と通信している移動局の受信信号に大きな干渉を与え
てしまう。また、マイクロセルの移動局の送信電力は、
マイクロセル基地局と通信している移動局の送信電力よ
り大きくなることがあるために、マイクロセル基地局の
受信信号に大きな干渉を与えてしまう。このような干渉
を回避するため、マイクロセルとマイクロセル基地局と
では異なる無線周波数を用いる必要がある。このときに
は、マイクロセル基地局からマイクロセル基地局への切
り替えに際して、周辺基地局監視やハンドオフ時に周波
数を切り替える必要がある。However, even in CDMA, the base stations may not be able to use the same radio frequency. This is for example
This is the case of a macrocell base station with a wide communication range overlaid on a microcell base station with a small communication range. Since the transmission power of the microcell base station is smaller than the transmission power of the microcell base station, if the same radio frequency is used, the transmission signal of the microcell base station is transmitted by the mobile station communicating with the microcell base station. Large interference is given to the received signal. Also, the transmission power of the microcell mobile station is
Since the transmission power of the mobile station communicating with the microcell base station may be higher than that of the mobile station, the received signal of the microcell base station may be greatly interfered. In order to avoid such interference, it is necessary to use different radio frequencies for the microcell and the microcell base station. At this time, when switching from the microcell base station to the microcell base station, it is necessary to switch the frequency at the time of monitoring a nearby base station or performing handoff.

CDMAではTDMAのような空き時間がないため、移動局に
おいて周辺基地局監視を行う代わりに、周辺基地局にお
いて、その移動局の送信信号を受信して受信レベルを検
出し、最大のレベルの基地局を新基地局とする方法があ
る。このときには、各基地局にはレベル測定用の受信機
が必要で、通信中の移動局が多くなるに連れて基地局側
のレベル測定用受信機数が多く必要になる。さらに、レ
ベル測定と比較などの制御処理が膨大になる。また、ハ
ンドオフ時には、無線周波数を切り替えることになるた
め通信が瞬断してしまうことになる。In CDMA, since there is no idle time unlike TDMA, instead of monitoring the surrounding base station at the mobile station, the surrounding base station receives the transmission signal of the mobile station and detects the reception level, and the base station of the maximum level There is a method of making a station a new base station. At this time, each base station needs a receiver for level measurement, and as the number of mobile stations in communication increases, the number of level measurement receivers on the base station side increases. Further, control processing such as level measurement and comparison becomes enormous. Further, at the time of handoff, the radio frequency is switched, so that the communication is momentarily interrupted.

発明の開示本発明の目的は、以上の課題を解決するために、CDMA
移動通信において、異なる無線周波数を用いる基地局か
らの受信信号を測定する空き時間を有し、その時間に周
辺基地局からの信号レベルを監視することができる送受
信方法を提供することにある。DISCLOSURE OF THE INVENTION An object of the present invention is to provide a CDMA
It is an object of the present invention to provide a transmission / reception method which has a free time for measuring a signal received from a base station using a different radio frequency in mobile communication and can monitor a signal level from a peripheral base station at that time.

また、本発明の目的は、CDMA移動通信において、異な
る無線周波数を用いる基地局間のハンドオフを瞬断のな
いように行うため、通信中に空き時間を作ることのでき
るハンドオフ中の送受信方法を提供することにある。Also, an object of the present invention is to provide a transmission / reception method during handoff that can make idle time during communication so that handoff between base stations using different radio frequencies is performed without instantaneous interruption in CDMA mobile communication. Is to do.

第１に、本発明によれば、第１の基地局は、ユーザデ
ータを誤り訂正符号化したのち、前記ユーザデータおよ
び誤り訂正チェックビットを１次変調して得られる狭帯
域変調信号を拡散符号で広帯域信号へ２次変調して送信
し、移動局は、前記広帯域信号を狭帯域変調信号へ変換
し、復調し、誤り訂正復号処理して前記ユーザデータを
再生するCDMA移動通信方法において、前記移動局は、前記第１の基地局からの送信された前記ユーザデータ
受信中の第１の時間に、前記ユーザデータを復調する過
程と、前記誤り訂正チェックビット受信中の第２の時間に、
前記誤り訂正復号処理を休止し、誤り訂正復号化しない
前記ユーザデータを出力する過程と、前記第２の時間に、受信周波数を、前記第１の基地局
とは使用周波数の異なる第２の基地局の無線周波数に切
り替えて、前記第２の基地局の受信レベルを監視する過
程とを具備することを特徴とするCDMA移動通信方法が提供
される。First, according to the present invention, the first base station performs error correction coding of user data, and then performs spread code conversion on the narrowband modulation signal obtained by primary modulating the user data and the error correction check bits. In the CDMA mobile communication method, the mobile station converts the wideband signal into a narrowband modulated signal, demodulates the error, and performs error correction decoding processing to reproduce the user data. A mobile station demodulates the user data at a first time during reception of the user data transmitted from the first base station; and at a second time during reception of the error correction check bit,
A step of suspending the error correction decoding process and outputting the user data not subjected to the error correction decoding, and, at the second time, changing a reception frequency to a second base having a different operating frequency from the first base station. Monitoring the reception level of the second base station by switching to the radio frequency of the station, thereby providing a CDMA mobile communication method.

上記CDMA移動通信方法において、前記第１の基地局と
前記第２の基地局との間のハンドオフ期間中、前記第１の基地局では、前記第１の時間に前記ユーザ
データを送信し、前記第２の時間には送信を休止する過
程と、前記第２の基地局では、前記第２の時間に前記ユーザ
データを送信し、前記第１の時間には送信を休止する過
程と、前記移動局では、前記第１の時間に前記第１の基地局
からの信号を受信復調し、前記第２の時間に前記第２の
基地局の周波数に受信機の周波数を切り替えて、該第２
の基地局からの信号を受信復調し、前記第１の基地局か
らの信号と前記第２の基地局からの信号とを合成してユ
ーザデータを再生する過程とを具備するようにしてもよい。In the CDMA mobile communication method, during a handoff period between the first base station and the second base station, the first base station transmits the user data at the first time, Suspending transmission at a second time; transmitting, at the second base station, the user data at the second time; suspending transmission at the first time; The station receives and demodulates the signal from the first base station at the first time, switches the frequency of the receiver to the frequency of the second base station at the second time,
Receiving and demodulating a signal from the base station, and combining the signal from the first base station and the signal from the second base station to reproduce user data. .

上記CDMA移動通信方法において、前記ハンドオフ期間
中、前記移動局では、ユーザデータを送信すべき第３の時
間に、ユーザデータを前記第１の基地局に第１の無線周
波数で送信し、誤り訂正チェックビットを送信すべき第
４の時間に、前記ユーザデータを前記第２の基地局に第
２の無線周波数で送信する過程と、前記第１の基地局では、前記第３の時間に受信した前
記ユーザデータを復調する過程と、前記第２の基地局では、前記第４の時間に受信した前
記ユーザデータを復調する過程と、前記第１の基地局および前記第２の基地局の上位局で
は、それらの復調信号を合成することにより前記ユーザ
データを再生する過程とを具備するようにしてよい。In the CDMA mobile communication method, during the handoff period, the mobile station transmits user data to the first base station at a first radio frequency at a third time when user data is to be transmitted, and performs error correction. Transmitting the user data to the second base station at a second radio frequency at a fourth time at which a check bit is to be transmitted; and receiving the user data at the third time at the first base station. A step of demodulating the user data; a step of demodulating the user data received at the fourth time in the second base station; an upper station of the first base station and the second base station And reproducing the user data by combining the demodulated signals.

上記CDMA移動通信方法において、前記第１の基地局と
前記第２の基地局との間のハンドオフ期間中、前記第１の基地局では、前記第１の時間に前記ユーザ
データを送信し、前記第２の時間には送信を休止する過
程と、前記第２の基地局では、前記第２の時間に前記誤り訂
正チェックビットを送信し、前記第１の時間には送信を
休止する過程と、前記移動局では、前記第１の時間に第１の基地局から
の信号を受信復調し、前記第２の時間に前記第２の基地
局の無線周波数に受信機の周波数を切り替えて該第２の
基地局からの信号を受信復調し、前記第１の基地局から
の前記ユーザデータと前記第２の基地局からの前記誤り
訂正チェックビットとを用いて前記ユーザデータを再生
する過程とを具備するようにしてもよい。In the CDMA mobile communication method, during a handoff period between the first base station and the second base station, the first base station transmits the user data at the first time, Suspending transmission at a second time; transmitting, at the second base station, the error correction check bit at the second time, and suspending transmission at the first time; The mobile station receives and demodulates a signal from a first base station at the first time, and switches a frequency of a receiver to a radio frequency of the second base station at the second time to perform the second Receiving and demodulating a signal from the base station, and reproducing the user data using the user data from the first base station and the error correction check bit from the second base station. You may make it.

上記CDMA移動通信方法において、前記ハンドオフ期間
中、前記移動局では、ユーザデータを送信すべき第３の時
間に、ユーザデータを前記第１の基地局に第１の無線周
波数で送信し、誤り訂正チェックビットを送信すべき第
４の時間に、誤り訂正チェックビットを前記第２の基地
局に第２の無線周波数で送信する過程と、前記第１の基地局では、前記第３の時間に受信した前
記ユーザデータを復調する過程と、前記第２の基地局では、前記第４の時間に受信した前
記誤り訂正チェックビットを復調する過程と、前記第１の基地局および前記第２の基地局の上位局で
は、それらの復調信号を用いて誤り訂正復号を行うこと
によって、前記ユーザデータを再生する過程とを具備するようにしてもよい。In the CDMA mobile communication method, during the handoff period, the mobile station transmits user data to the first base station at a first radio frequency at a third time when user data is to be transmitted, and performs error correction. Transmitting an error correction check bit to the second base station at a second radio frequency at a fourth time at which a check bit is to be transmitted; and receiving at the third time at the first base station. Demodulating the user data thus obtained, demodulating the error correction check bit received at the fourth time in the second base station, and the first base station and the second base station. The upper station may perform the error correction decoding using the demodulated signals to reproduce the user data.

第２に、本発明によれば、第１の基地局は、ユーザデ
ータを誤り訂正符号化したのち、前記ユーザデータおよ
び誤り訂正チェックビットに多値変調による１次変調を
行って得た狭帯域変調信号を拡散符号で広帯域信号へ２
次変調して送信し、移動局は、前記広帯域信号を狭帯域
変調信号へ変換し、復調し、誤り訂正復号処理して前記
ユーザデータを再生するCDMA移動通信方法において、前
記移動局が、前記第１の基地局とは異なる第２の基地局
からの信号の受信レベルを監視する受信レベル監視期間
中は、前記第１の基地局では、前記ユーザデータおよび誤り
訂正チェックビットを、前記多値変調の多値数を大きく
して第１の時間に送信することによって、送信を休止す
る第２の時間を作る過程と、前記移動局では、前記第１の時間に前記多値変調の多
値数を大きくして受信信号を復調し、誤り訂正復号処理
して、前記ユーザデータを再生するとともに、前記第２
の時間において、受信周波数を前記第２の基地局の無線
周波数に切り替えて、該第２の基地局の受信レベルを監
視する過程とを具備することを特徴とするCDMA移動通信
方法が提供される。Secondly, according to the present invention, the first base station performs error correction coding on user data, and then performs narrow band narrowband modulation by performing primary modulation by multi-level modulation on the user data and error correction check bits. Modulate signal into wideband signal with spread code 2
In the CDMA mobile communication method of transmitting the next modulated and transmitting, the mobile station converts the wideband signal into a narrowband modulated signal, demodulates, and performs error correction decoding processing to reproduce the user data. During a reception level monitoring period for monitoring a reception level of a signal from a second base station different from the first base station, the first base station transmits the user data and the error correction check bit to the multi-level Creating a second time for pausing transmission by increasing the multi-level number of modulation and transmitting at a first time; and wherein the mobile station performs multi-level modulation of the multi-level modulation at the first time. While increasing the number, the received signal is demodulated, error-correction decoded, and the user data is reproduced.
Switching the reception frequency to the radio frequency of the second base station at the time of (i), and monitoring the reception level of the second base station. .

上記CDMA移動通信方法において、前記第１の基地局
と、前記第２の基地局との間のハンドオフ期間中は、前記第１の基地局では、前記第１の時間に前記ユーザ
データおよびその誤り訂正チェックビットを送信する過
程と、前記第２の基地局では、前記第２の時間に前記ユーザ
データおよびその誤り訂正チェックビットを送信する過
程と、前記移動局では、前記第１の時間に前記第１の基地局
からの前記ユーザデータおよび誤り訂正チェックビット
を受信するとともに、前記第２の時間に受信周波数を前
記第２の基地局の無線周波数に切り替えて前記ユーザデ
ータおよび誤り訂正チェックビットを受信し、前記第１
の基地局からの信号と前記第２の基地局からの信号とを
合成して前記ユーザデータを再生する過程とを具備するようにしてもよい。In the CDMA mobile communication method, during a hand-off period between the first base station and the second base station, the first base station transmits the user data and an error thereof at the first time. Transmitting a correction check bit, the second base station transmitting the user data and its error correction check bit at the second time, and the mobile station transmits the user data and the error correction check bit at the first time. While receiving the user data and the error correction check bit from the first base station, the receiving frequency is switched to the radio frequency of the second base station at the second time to change the user data and the error correction check bit. Receiving the first
Combining the signal from the base station and the signal from the second base station to reproduce the user data.

第３に、本発明によれば、ユーザデータを誤り訂正符
号化したのち、前記ユーザデータおよび誤り訂正チェッ
クビットを１次変調して得えられる狭帯域変調信号を拡
散符号で広帯域信号へ２次変調して送信する第１の基地
局と、前記広帯域信号を狭帯域変調信号へ変換し、復調
し、誤り訂正復号処理して前記ユーザデータを再生する
移動局とを備えたCDMA移動通信システムにおいて、前記
移動局は、前記第１の基地局から送信された前記ユーザデータ受
信中の第１の時間に、前記ユーザデータを復調する復調
部と、前記誤り訂正チェックビット受信中の第２の時間に、
前記誤り訂正復号処理を休止し、誤り訂正復号化しない
前記ユーザデータを出力する誤り訂正復号部と、前記第２の時間に、受信周波数を、前記第１の基地局
とは使用周波数の異なる第２の基地局の無線周波数に切
り替える周波数切換手段と、前記第２の基地局からの信号の受信レベルを監視する
受信レベル測定部とを具備することを特徴とするCDMA移動通信システムが
提供される。Third, according to the present invention, after the user data is error-correction-coded, the narrow-band modulation signal obtained by primary-modulating the user data and the error-correction check bit is converted into a wideband signal by a spread code. A CDMA mobile communication system comprising: a first base station that performs modulation and transmission; and a mobile station that converts the wideband signal to a narrowband modulation signal, demodulates, performs error correction decoding, and reproduces the user data. A mobile station comprising: a demodulation unit for demodulating the user data at a first time during reception of the user data transmitted from the first base station; and a second time during reception of the error correction check bit. To
An error correction decoding unit that suspends the error correction decoding process and outputs the user data that is not subjected to the error correction decoding; and, at the second time, a reception frequency different from a frequency used by the first base station. A frequency switching means for switching to a radio frequency of the second base station; and a reception level measuring unit for monitoring a reception level of a signal from the second base station. .

上記CDMA移動通信システムにおいて、前記第１の基地
局と前記第２の基地局との間のハンドオフを指令する上
位局を備え、前記第１の基地局は、前記上位局からのハンドオフ指
令に基づいて、前記第１の時間に前記ユーザデータを送
信し、前記第２の時間には送信を休止させる第１の制御
手段を具備し、前記第２の基地局は、前記ハンドオフ指令に基づい
て、前記第２の時間に前記ユーザデータを送信し、前記
第１の時間には送信を休止させる第２の制御手段を具備
し、前記移動局は、受信機の周波数を前記第１の基地局の
送信周波数および前記第２の送信周波数の一方に合わせ
る受信周波数切換手段と、前記第１の時間に前記第１の
基地局からの信号を受信復調するとともに、前記第２の
時間に前記第２の基地局からの信号を受信復調し、前記
第１の基地局からの信号と前記第２の基地局からの信号
とを合成してユーザデータを再生する復調部とを具備す
るようにしてもよい。The CDMA mobile communication system, further comprising: an upper station instructing a handoff between the first base station and the second base station, wherein the first base station is based on a handoff instruction from the upper station. And transmitting the user data at the first time and suspending the transmission at the second time. The second base station, based on the handoff command, The mobile station includes second control means for transmitting the user data at the second time and suspending the transmission at the first time, wherein the mobile station changes a frequency of a receiver to a frequency of the first base station. Receiving frequency switching means for adjusting to one of a transmission frequency and the second transmission frequency, and receiving and demodulating a signal from the first base station at the first time, and receiving the second signal at the second time. Receive and demodulate the signal from the base station, A demodulation unit that combines the signal from the first base station and the signal from the second base station to reproduce user data may be provided.

上記CDMA移動通信システムにおいて、前記移動局は、送信機の送信周波数を前記第１の基地
局の受信周波数および前記第２の基地局の受信周波数の
一方に切り換える送信周波数切換手段と、ハンドオフ期
間中、ユーザデータを送信すべき第３の時間に、ユーザ
データを前記第１の基地局の受信周波数で送信し、誤り
訂正チェックビットを送信すべき第４の時間に、前記ユ
ーザデータを前記第２の基地局の受信周波数で送信する
送信手段を具備し、前記第１の基地局は、前記第３の時間に受信した前記
ユーザデータを復調する第１の復調部を具備し、前記第２の基地局は、前記第４の時間に受信した前記
ユーザデータを復調する第２の復調部を具備し、前記上位局では、前記各復調部で復調した復調信号を
合成することにより前記ユーザデータを再生する手段を
具備するようにしてもよい。In the CDMA mobile communication system, the mobile station includes: a transmission frequency switching unit configured to switch a transmission frequency of a transmitter to one of a reception frequency of the first base station and a reception frequency of the second base station; Transmitting the user data at a reception frequency of the first base station at a third time to transmit the user data, and transmitting the user data to the second time at a fourth time to transmit an error correction check bit. The first base station includes a first demodulation unit that demodulates the user data received at the third time, wherein the second demodulation unit demodulates the user data received at the third time. The base station includes a second demodulator for demodulating the user data received at the fourth time, and the upper station combines the demodulated signals demodulated by the respective demodulators to synthesize the user data. It may be provided with a means for reproducing.

上記CDMA移動通信システムにおいて、前記第１の基地
局と前記第２の基地局との間のハンドオフを指令する上
位局を備え、前記第１の基地局は、前記上位局からのハ
ンドオフ指令に基づいて、前記第１の時間に前記ユーザ
データを送信し、前記第２の時間には送信を休止させる
第１の制御手段を具備し、前記第２の基地局は、前記ハンドオフ指令に基づい
て、前記第２の時間に前記誤り訂正チェックビットを送
信し、前記第１の時間には送信を休止させる第２の制御
手段を具備し、前記移動局は、受信機の周波数を前記第１の基地局の
送信周波数および前記第２の送信周波数の一方に合わせ
る受信周波数切換手段と、前記第１の時間に前記第１の
基地局からの信号を受信復調するとともに、前記第２の
時間に前記第２の基地局からの信号を受信復調し、前記
第１の基地局からの前記ユーザデータと前記第２の基地
局からの前記誤り訂正チェックビットとを用いて前記ユ
ーザデータを再生する復調部とを具備するようにしても
よい。In the CDMA mobile communication system, the mobile station further includes an upper station for instructing a handoff between the first base station and the second base station, wherein the first base station is based on a handoff instruction from the upper station. And transmitting the user data at the first time and suspending the transmission at the second time. The second base station, based on the handoff command, The mobile station further comprises a second control unit for transmitting the error correction check bit at the second time and suspending the transmission at the first time, wherein the mobile station sets a frequency of a receiver to the first base station. Receiving frequency switching means for adjusting to one of a transmission frequency of a station and the second transmission frequency, and receiving and demodulating a signal from the first base station at the first time; 2 from the base station Demodulates, may be provided with a demodulator for reproducing the user data by using said error correction check bits from said user data and said second base station from said first base station.

以上CDMA移動通信システムにおいて、前記移動局は、送信機の送信周波数を前記第１の基地
局の受信周波数および前記第２の基地局の受信周波数の
一方に切り換える送信周波数切換手段と、前記ハンドオ
フ期間中、ユーザデータを送信すべき第３の時間に、ユ
ーザデータを前記第１の基地局の受信周波数で送信し、
誤り訂正チェックビットを送信すべき第４の時間に、誤
り訂正チェックビットを前記第２の基地局の受信周波数
で送信する送信手段とを具備し、前記第１の基地局は、前記第３の時間に送信した前記
ユーザデータを復調する復調部を具備し、前記第２の基地局は、前記第４の時間に受信した前記
誤り訂正チェックビットを復調する復調部を具備し、前記上位局は、前記各復調部から出力された復調信号
を用いて誤り訂正復号を行うことによって、前記ユーザ
データを再生する手段を具備するようにしてもよい。In the above CDMA mobile communication system, the mobile station includes: a transmission frequency switching unit configured to switch a transmission frequency of a transmitter to one of a reception frequency of the first base station and a reception frequency of the second base station; Transmitting the user data at a reception frequency of the first base station at a third time during which the user data is to be transmitted;
Transmitting means for transmitting an error correction check bit at a reception frequency of the second base station at a fourth time at which an error correction check bit is to be transmitted, the first base station comprising: A demodulation unit for demodulating the user data transmitted at time; the second base station includes a demodulation unit for demodulating the error correction check bit received at the fourth time; And means for reproducing the user data by performing error correction decoding using demodulated signals output from the demodulation units.

第４に、本発明によれば、ユーザデータを誤り訂正符
号化したのち、前記ユーザデータおよび誤り訂正チェッ
クビットに多値変調による１次変調を行って得た狭帯域
変調信号を拡散符号で広帯域信号へ２次変調して送信す
る第１の基地局と、前記広帯域信号を狭帯域変調信号へ
変換し、復調し、誤り訂正復号処理して前記ユーザデー
タを再生する移動局とを備えたCDMA移動通信システムに
おいて、前記第１の基地局は、前記ユーザデータおよび誤り訂
正チェックビットの、前記多値変調の多値数を変化させ
る第１の多値数制御部と、前記移動局が、前記第１の基
地局とは異なる第２の基地局からの信号の受信レベルを
監視する受信レベル監視期間中は、前記多値数を大きく
して第１の時間に送信することによって、送信を休止す
る第２の時間を作る手段とを具備し、前記移動局は、受信機の周波数を前記第１の基地局の
送信周波数および前記第２の送信周波数の一方に合わせ
る受信周波数切換手段と、前記多値変調の多値数を変化
させる第２の多値数制御部と、前記第１の時間に前記多
値数を大きくして受信信号を復調し、誤り訂正復号処理
して、前記ユーザデータを再生する復調部と、前記第２
の時間において、受信周波数を前記第２の基地局の送信
周波数に切り換えて、該第２の基地局の受信レベルを監
視する受信レベル測定部とを具備することを特徴とする
CDMA移動通信システムが提供される。Fourth, according to the present invention, after error correction coding of user data, a narrow band modulation signal obtained by performing primary modulation by multi-level modulation on the user data and the error correction check bits is subjected to a wideband spreading code. A CDMA system comprising: a first base station that performs second-order modulation on a signal and transmits the signal; and a mobile station that converts the wide-band signal into a narrow-band modulated signal, demodulates, performs error correction decoding, and reproduces the user data. In the mobile communication system, the first base station, the user data and the error correction check bit, a first multi-level control unit for changing the multi-level number of the multi-level modulation, the mobile station, During a reception level monitoring period in which a reception level of a signal from a second base station different from the first base station is monitored, the transmission is paused by increasing the multi-level number and transmitting the signal at the first time. Second time to do Means for making the mobile station adjust the frequency of a receiver to one of the transmission frequency of the first base station and the second transmission frequency; and the multi-level modulation of the multi-level modulation. A second multi-level control section for changing the number, a demodulation section for increasing the multi-level number at the first time, demodulating a received signal, performing error correction decoding processing, and reproducing the user data; , The second
A reception level measuring unit that switches the reception frequency to the transmission frequency of the second base station at the time, and monitors the reception level of the second base station.
A CDMA mobile communication system is provided.

上記CDMA移動通信システムにおいて、前記第１の基地
局と前記第２の基地局との間のハンドオフを指令する上
位局を備え、前記第１の基地局は、前記上位局からのハ
ンドオフ指令に基づいて、前記第１の時間に前記ユーザ
データおよびその誤り訂正チェックビットを送信する第
１の送信手段を具備し、前記第２の基地局は、前記ハンドオフ指令に基づい
て、前記第２の時間に前記ユーザデータおよびその誤り
訂正チェックビットを送信する第２の送信手段を具備
し、前記移動局は、前記第１の時間に前記第１の基地局か
らの前記ユーザデータおよび誤り訂正チェックビットを
受信するとともに、前記第２の時間に受信周波数を前記
第２の基地局の送信周波数に切り替えて前記ユーザデー
タおよび誤り訂正チェックビットを受信し、前記第１の
基地局からの信号と前記第２の基地局からの信号とを合
成して前記ユーザデータを再生する手段を具備するよう
にしてよい。In the CDMA mobile communication system, the mobile station further includes an upper station for instructing a handoff between the first base station and the second base station, wherein the first base station is based on a handoff instruction from the upper station. And a first transmitting means for transmitting the user data and its error correction check bit at the first time, wherein the second base station transmits the user data and the error correction check bit at the second time based on the handoff command. The mobile station receives the user data and the error correction check bit from the first base station at the first time. And switching the reception frequency to the transmission frequency of the second base station at the second time to receive the user data and the error correction check bit, A signal from the signal and the second base station from the earth station synthesized to be so as to comprise means for reproducing the user data.

第５に、本発明によれば、ユーザデータを誤り訂正符
号化したのち１次変調して得られる狭帯域変調信号を拡
散符号で広帯域信号へ２次変調して送信する第１の基地
局と、前記広帯域信号を狭帯域変調信号へ変換し、復調
し、誤り訂正復号して前記ユーザデータを再生する移動
局とを備えたCDMA移動通信システムにおける移動局であ
って、前記移動局の受信機は、前記第１の基地局から送信された前記ユーザデータ受
信中の第１の時間に、前記ユーザデータを復調する復調
部と、前記誤り訂正チェックビット受信中の第２の時間に、
前記誤り訂正復号処理を休止し、誤り訂正復号化しない
前記ユーザデータを出力する誤り訂正復号部と、前記第２の時間に、受信周波数を、前記第１の基地局
とは使用周波数の異なる第２の基地局の無線周波数に切
り替える周波数切換部と、前記第２の基地局の受信レベルを監視する受信レベル
測定部とを具備することを特徴とする移動局が提供される。Fifth, according to the present invention, a first base station that performs second-order modulation on a narrow-band modulated signal obtained by subjecting user data to error correction encoding and then primary modulation to a broadband signal with a spreading code, and transmits A mobile station in a CDMA mobile communication system, comprising: a mobile station that converts the wideband signal into a narrowband modulation signal, demodulates the error, performs error correction decoding, and reproduces the user data. At a first time during reception of the user data transmitted from the first base station, a demodulation unit that demodulates the user data, at a second time during reception of the error correction check bit,
An error correction decoding unit that suspends the error correction decoding process and outputs the user data that is not subjected to the error correction decoding; and, at the second time, a reception frequency different from a frequency used by the first base station. A mobile station comprising: a frequency switching unit that switches to a radio frequency of a second base station; and a reception level measurement unit that monitors a reception level of the second base station.

上記移動局において、前記移動局の受信機は、受信周波数を、前記第１の基地局の送信周波数および
前記第２の基地局の送信周波数の一方に合わせる受信周
波数切換部と、前記第１の基地局と前記第２の基地局との間のハンド
オフ期間中、前記第１の時間に前記第１の基地局からの
信号を受信復調するとともに、前記第２の時間に前記第
２の基地局からの信号を受信復調し、前記第１の基地局
からの信号と前記第２の基地局からの信号とを合成して
ユーザデータを再生する復調部とを具備し、前記移動局の送信機は、送信周波数を、前記第１の基地局の受信周波数および
前記第２の基地局の受信周波数に合わせる送信周波数切
換部と前記ハンドオフ中には、ハンドオフを送信すべき第３
の時間に、ユーザデータを前記第１の基地局の受信周波
数で送信するとともに、誤り訂正チェックビットを送信
すべき第４の時間に、前記ユーザデータを前記第２の基
地局の受信周波数で送信する送信手段と、前記第１の基地局では、前記第３の時間に受信した前
記ユーザデータを復調する過程と、前記第２の基地局では、前記第４の時間に受信した前
記ユーザデータを復調する過程と、前記第１の基地局および前記第２の基地局の上位局で
は、それらの復調信号を合成することにより前記ユーザ
データを再生する過程とを具備するようにしてもよい。In the mobile station, a receiver of the mobile station includes: a reception frequency switching unit that adjusts a reception frequency to one of a transmission frequency of the first base station and a transmission frequency of the second base station; During a hand-off period between a base station and the second base station, a signal from the first base station is received and demodulated at the first time, and the second base station is received at the second time. And a demodulator for combining the signal from the first base station and the signal from the second base station to reproduce user data, and a transmitter for the mobile station. A transmission frequency switching unit that adjusts a transmission frequency to a reception frequency of the first base station and a reception frequency of the second base station, and a third to transmit a handoff during the handoff.
At the time, the user data is transmitted at the reception frequency of the first base station, and the user data is transmitted at the reception frequency of the second base station at a fourth time at which an error correction check bit is to be transmitted. The first base station demodulates the user data received at the third time; and the second base station transmits the user data received at the fourth time. A demodulation process and a process of reproducing the user data by synthesizing the demodulated signals in an upper station of the first base station and the second base station may be provided.

第６に、本発明によれば、ユーザデータを誤り訂正符
号化したのち、前記ユーザデータおよび誤り訂正チェッ
クビットに値値変調による１次変調を行って得た狭帯域
変調信号を拡散符号で広帯域信号へ２次変調して送信す
る第１の基地局と、前記広帯域信号を狭帯域変調信号へ
変換し、復調し、誤り訂正復号処理して前記ユーザデー
タを再生する移動局とを備え、前記第１の基地局は、前
記ユーザデータおよび誤り訂正チェックビットを、前記
多値変調の多値数を大きくして第１の時間に送信するこ
とによって、送信を休止する第２の時間を作る、CDMA移
動システムにおける移動局であって、前記移動局の受信機は、前記移動局が、前記第１の基地局とは異なる第２の基
地局からの信号の受信レベルを監視する受信レベル監視
期間中は、前記第１の時間に前記多値変調の多値数を大
きくする多値数切換部と、前記第１の時間において、前記ユーザデータおよび誤
り訂正チェックビットを復調し、誤り訂正復号処理し
て、前記ユーザデータを再生する手段と、前記受信機の受信周波数を、前記第１の基地局の送信
周波数および前記第２の基地局の送信周波数の一方に合
わせる受信周波数切換部と、前記第２の時間において、前記第２の基地局の受信レ
ベルを監視する受信レベル測定部とを具備することを特徴とする移動局が提供される。Sixth, according to the present invention, after error correction coding of user data, a narrow band modulation signal obtained by performing primary modulation by value-value modulation on the user data and error correction check bits is subjected to spread code by a spreading code. A first base station that performs secondary modulation on a signal and transmits the signal, and a mobile station that converts the wideband signal into a narrowband modulation signal, demodulates the error, performs error correction decoding, and reproduces the user data, A first base station for transmitting the user data and the error correction check bit at a first time by increasing a multi-level number of the multi-level modulation to create a second time for pausing transmission; A mobile station in a CDMA mobile system, wherein the receiver of the mobile station is a reception level monitoring period in which the mobile station monitors a reception level of a signal from a second base station different from the first base station. Inside is the above A multi-level switching unit for increasing the multi-level number of the multi-level modulation at time 1; demodulating the user data and error correction check bits at the first time, performing error correction decoding processing, Means for reproducing data; a reception frequency switching unit for adjusting a reception frequency of the receiver to one of a transmission frequency of the first base station and a transmission frequency of the second base station; And a reception level measuring unit for monitoring the reception level of the second base station.

上記移動局において、前記移動局の受信機の受信周波
数切換部は、前記第１の基地局と前記第２の基地局との
間のハンドオフ期間中は、受信周波数を、前記第１の時
間には前記第１の基地局の送信周波数に切り換え、前記
第２の時間には前記第２の基地局の送信周波数に切り換
え、前記再生する手段は、前記第１の基地局からの信号
と前記第２の基地局から信号とを合成して前記ユーザデ
ータを再生するようにしてもよい。In the mobile station, a reception frequency switching unit of a receiver of the mobile station, during a handoff period between the first base station and the second base station, changes a reception frequency to the first time. Switches to the transmission frequency of the first base station, switches to the transmission frequency of the second base station at the second time, and the means for reproducing includes a signal from the first base station and the second The user data may be reproduced by synthesizing a signal from the second base station.

本発明によれば、CDMA移動通信において、移動局は異
なる無線周波数を用いる基地局からの信号レベルを測定
する空き時間を作ることができるので、移動局はその時
間に基地局を監視することがきる。According to the present invention, in the CDMA mobile communication, the mobile station can make an idle time for measuring the signal level from the base station using a different radio frequency, so that the mobile station can monitor the base station at that time. Wear.

また、CDMA移動通信において、異なる無線周波数を用
いる基地局間のハンドオフにおいて、基地局と移動局の
ハンドオフ期間に、両基地局の信号を受信でき、かつ両
基地局に同一送信データを送信することができるので、
ハンドオフ中の通信に瞬断のないようにできる。Also, in CDMA mobile communication, in handoff between base stations using different radio frequencies, signals of both base stations can be received and the same transmission data is transmitted to both base stations during a handoff period between the base station and the mobile station. So you can
Communication during handoff can be prevented from being interrupted instantaneously.

図面の簡単な説明図1Aおよび1Bは、それぞれ、本発明によるCDMA移動通
信システムの第１実施例の基地局の送信機および移動局
の受信機を示すブロック図である。BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are block diagrams respectively showing a transmitter of a base station and a receiver of a mobile station of a first embodiment of the CDMA mobile communication system according to the present invention.

図２は、第１実施例における、移動局での受信レベル
測定のタイミングチャートである。FIG. 2 is a timing chart of the reception level measurement at the mobile station in the first embodiment.

図3Aおよび3Bは、それぞれ、本発明によるCDMA移動通
信システムの第２実施例の基地局の送信機および移動局
の受信機を示すブロック図である。3A and 3B are block diagrams respectively showing a transmitter of a base station and a receiver of a mobile station in a second embodiment of the CDMA mobile communication system according to the present invention.

図４は、第２実施例における、移動局での受信レベル
測定のタイミングチャートである。FIG. 4 is a timing chart of the reception level measurement at the mobile station in the second embodiment.

図５は、本発明によるCDMA移動通信システムの第３−
第５実施例において、ハンドオフを行うときのシステム
構成を説明するブロック図である。FIG. 5 is a block diagram of a CDMA mobile communication system according to the present invention.
FIG. 16 is a block diagram illustrating a system configuration when performing handoff in a fifth embodiment.

図６は、本発明によるCDMA移動通信システムの第３実
施例の移動局の送信機を示すブロック図である。FIG. 6 is a block diagram showing a transmitter of a mobile station of a third embodiment of the CDMA mobile communication system according to the present invention.

図７は、第３実施例におけるハンドオフ中の基地局の
動作を示すタイミングチャートである。FIG. 7 is a timing chart showing the operation of the base station during handoff in the third embodiment.

図８は、第３実施例におけるハンドオフ中の移動局の
動作を示すタイミングチャートである。FIG. 8 is a timing chart showing the operation of the mobile station during handoff in the third embodiment.

図９は、本発明によるCDMA移動通信システムの第４実
施例の移動局の送信機を示すブロック図である。FIG. 9 is a block diagram showing a transmitter of a mobile station according to a fourth embodiment of the CDMA mobile communication system according to the present invention.

図10は、第４実施例におけるハンドオフ中の基地局の
動作を示すタイミングチャートである。FIG. 10 is a timing chart showing the operation of the base station during handoff in the fourth embodiment.

図11は、本発明によるCDMA移動通信システムの第５実
施例におけるハンドオフ中の基地局の動作を示すタイミ
ングチャートである。FIG. 11 is a timing chart showing the operation of the base station during handoff in the fifth embodiment of the CDMA mobile communication system according to the present invention.

図12は、本発明によるCDMA移動通信システムの第６実
施例におけるハンドオフ中の移動局の動作を示すタイミ
ングチャートである。FIG. 12 is a timing chart showing the operation of the mobile station during handoff in the sixth embodiment of the CDMA mobile communication system according to the present invention.

発明を実施するための最良の形態以下、図面を参照して、本発明の実施例を説明する。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

第１実施例図1Aおよび1Bは、本発明によるCDMA移動通信システム
の第１実施例の構成を示すブロック図である。図1Aは基
地局の送信機の構成、図1Bは移動局の受信機の構成を示
す。図２は、本発明に使用されるフレーム構成および受
信タイミングを示す。First Embodiment FIGS. 1A and 1B are block diagrams showing a configuration of a first embodiment of a CDMA mobile communication system according to the present invention. FIG. 1A shows the configuration of the transmitter of the base station, and FIG. 1B shows the configuration of the receiver of the mobile station. FIG. 2 shows a frame configuration and reception timing used in the present invention.

図1Aにおいて、101は、入力されたデータをフレーム
化するフレーム構成部、102はフレーム構成されたデー
タを誤り訂正符号化する誤り訂正符号化部、103は誤り
訂正符号化部102の出力を位相変調する１次変調部であ
る。105は、１次変調された信号に対して、拡散系列発
生器104で生成した拡散符号で拡散する２次変調部であ
る。106は拡散された信号を送信周波数に変換する周波
数変換部である。107は電力増幅を行う送信電力増幅部
である。109は、上述した各部を制御する主制御部であ
る。In FIG. 1A, reference numeral 101 denotes a frame configuration unit that frames input data, 102 denotes an error correction encoding unit that performs error correction encoding on framed data, and 103 denotes a phase of an output of the error correction encoding unit 102. This is a primary modulation unit that performs modulation. Reference numeral 105 denotes a secondary modulation unit that spreads the primary modulated signal with a spreading code generated by the spreading sequence generator 104. Reference numeral 106 denotes a frequency conversion unit that converts the spread signal into a transmission frequency. Reference numeral 107 denotes a transmission power amplifier that performs power amplification. Reference numeral 109 denotes a main control unit that controls each unit described above.

図1Bにおいて、151は受信信号をベースバンドに変換
する周波数変換部であり、152はこのベースバンド信号
を拡散系列発生器153の発生した拡散符号で逆拡散する
相関器である。逆拡散された信号は、復調部154で復調
され、符号判別部157でもとの信号に戻る。158は誤り訂
正復号部で、戻された信号は誤り訂正される。159は速
度変換部で、元の符号速度に変換されて完全にもと信号
にもどる。155は受信レベル測定部、156は主制御部、16
0は副制御部である。主制御部156は上述した受信機各部
を制御する。主制御部156には、誤り訂正復号部158から
供給されたフレームデータから抽出された制御情報が入
力される。副制御部160は、主制御部156によって制御さ
れる。In FIG. 1B, reference numeral 151 denotes a frequency conversion unit that converts a received signal into a baseband, and 152 denotes a correlator that despreads the baseband signal with a spreading code generated by a spreading sequence generator 153. The despread signal is demodulated in demodulation section 154 and returned to the original signal in code discrimination section 157. An error correction decoding unit 158 corrects an error in the returned signal. Reference numeral 159 denotes a rate conversion unit, which converts the code rate into the original code rate and returns to the original signal. 155 is a reception level measurement unit, 156 is a main control unit, 16
0 is a sub control unit. The main control unit 156 controls each unit of the receiver described above. The control information extracted from the frame data supplied from the error correction decoding unit 158 is input to the main control unit 156. The sub control unit 160 is controlled by the main control unit 156.

副制御部160は、周波数切換部162、拡散符号切換部16
4、イネーブル信号発生部166およびレベル測定制御部16
8を有し、主制御部156からの制御情報に基づいて、受信
周波数の切り換え、拡散符号の切り換え、誤り訂正復号
の実行／休止および受信レベル測定のタイミングを制御
する。The sub control unit 160 includes a frequency switching unit 162, a spreading code switching unit 16
4.Enable signal generator 166 and level measurement controller 16
8, which controls the switching of the reception frequency, the switching of the spreading code, the execution / pause of the error correction decoding, and the timing of the reception level measurement based on the control information from the main control unit 156.

図1Aに示す基地局の送信部の動作を説明する。基地局
におけるユーザデータ系列は、まず、フレーム構成部10
1であらかじめ定めた１フレーム時間（Tf）毎のデータ
にまとめられる。１フレーム分の送信データは、誤り訂
正符号化部102で誤り訂正符号化され、送信データ系列
と誤り訂正チェックビット系列が図２に示すように配置
される。この信号に対して、一次変調部103で例えば４
値位相変調を行う。４値位相変調信号はこのあと、拡散
系列発生部104からの拡散符号系列により広帯域信号へ
と２次変調部105で帯域拡散（２次変調）される。広帯
域信号は、周波数変換部106で無線周波数帯へ周波数変
換され、送信電力増幅部107で電力増幅されたのち、送
信される。The operation of the transmitting section of the base station shown in FIG. 1A will be described. The user data sequence in the base station is first transmitted to the frame forming unit 10
The data is collected into data for each one frame time (Tf) determined in advance in 1. The transmission data for one frame is subjected to error correction coding in error correction coding section 102, and a transmission data sequence and an error correction check bit sequence are arranged as shown in FIG. For this signal, the primary modulator 103
Value phase modulation is performed. The quaternary phase-modulated signal is thereafter subjected to band spreading (secondary modulation) by the secondary modulation unit 105 into a wideband signal by the spreading code sequence from the spreading sequence generation unit 104. The wideband signal is frequency-converted into a radio frequency band by frequency conversion section 106, power-amplified by transmission power amplification section 107, and then transmitted.

図1Bに示す移動局の受信機では、まず、周波数変換部
151が、受信信号をベースバンド信号に変換する。つぎ
に、相関器152で、拡散符号系列と受信信号との相関
（逆拡散）をとり、４値位相変調信号を得る。この拡散
符号系列は、基地局での送信に用いたものと同じ符号で
あり、拡散系列発生器153で発生される。その後、復調
部154で復調し、符号判定部157で符号判定する。通常の
通信時（通常モード）においては、判定データを誤り訂
正復号部158で誤り訂正し、速度変換部159で速度変換し
て基地局から送信されたデータを再生する。In the mobile station receiver shown in FIG.
151 converts the received signal into a baseband signal. Next, a correlation (despreading) between the spread code sequence and the received signal is performed by the correlator 152 to obtain a quaternary phase modulated signal. This spreading code sequence is the same code used for transmission at the base station, and is generated by spreading sequence generator 153. Thereafter, demodulation is performed by demodulation section 154, and code determination is performed by code determination section 157. At the time of normal communication (normal mode), the error correction decoding unit 158 corrects the error of the decision data, the speed conversion unit 159 converts the speed, and reproduces the data transmitted from the base station.

一方、周辺基地局監視モードのときには、移動局は、
副制御部160により、図２（Ａ）に示すように、フレー
ムのユーザデータ系列部分のみを受信するようにする。
この制御は、次のように行われる。まず、主制御部156
は、受信信号の各フレーム先頭部の制御データからユー
ザデータのデータ長を検出し、この情報を副制御部160
に供給する。この情報に基づいて、副制御部160のイネ
ーブル信号発生部166は、誤り訂正チェックビット期間
中の、誤り訂正復号部158による誤り訂正を休止させ
る。また、この期間中、副制御部160のレベル測定制御
部168は、受信レベル測定部155に信号を送り、受信レベ
ルの測定を指示する。また、周波数切換部162は、周波
数変換部151に信号を送り、受信機の周波数を周辺基地
局の周波数へ切り替えさせる。On the other hand, when in the peripheral base station monitoring mode, the mobile station
As shown in FIG. 2A, the sub control unit 160 receives only the user data sequence portion of the frame.
This control is performed as follows. First, the main control unit 156
Detects the data length of the user data from the control data at the beginning of each frame of the received signal, and transmits this information to the sub-controller 160
To supply. Based on this information, the enable signal generator 166 of the sub controller 160 suspends the error correction by the error correction decoder 158 during the error correction check bit period. Also, during this period, the level measurement control section 168 of the sub control section 160 sends a signal to the reception level measurement section 155 to instruct the reception level measurement. Further, frequency switching section 162 sends a signal to frequency conversion section 151 to switch the frequency of the receiver to the frequency of the peripheral base station.

図２（Ｂ）は、このときの受信周波数の切り替えのタ
イミングを示す。訂正能力を高めるために符号化率1/2
程度の誤り訂正符号を用いている（したがって、ユーザ
データ長とチェックビット長は同程度になる）。図２
（Ａ）において、foは通信中基地局の無線周波数、fkは
受信レベル測定をする相手の基地局の無線周波数であ
る。誤り訂正チェックビット期間中に、受信周波数を切
換えて、周波数fkの周辺基地局の受信レベルを測定して
いる様子を示している。こうすれば、受信を断すること
なく、周辺基地局監視ができる。FIG. 2B shows the timing of switching the reception frequency at this time. Coding rate 1/2 to increase correction capability
(For example, the user data length and the check bit length are almost the same). FIG.
In (A), fo is the radio frequency of the base station during communication, and fk is the radio frequency of the base station with which the reception level is measured. The figure shows how the reception frequency is switched during the error correction check bit period, and the reception level of the peripheral base station at the frequency fk is measured. By doing so, it is possible to monitor peripheral base stations without interrupting reception.

このように、本発明におけるレベル監視期間中におい
ては、誤り訂正復号しないことになる。このため、基地
局では送信データ系列部分の基地局送信パワーを増加す
ることにより、信頼性の劣化をある程度救済することも
できる。Thus, error correction decoding is not performed during the level monitoring period in the present invention. Therefore, the base station can relieve the deterioration of reliability to some extent by increasing the base station transmission power of the transmission data sequence portion.

第２実施例図３は本発明の他の実施例を示す。Second Embodiment FIG. 3 shows another embodiment of the present invention.

図3Aおよび3Bは、本発明によるCDMA移動通信システム
の第２実施例の構成を示すブロック図である。図3Aは基
地局の送信機の構成、図3Bは移動局の受信機の構成を示
す。図４は、本発明に使用されるフレーム構成および受
信タイミングを示す。3A and 3B are block diagrams showing the configuration of a second embodiment of the CDMA mobile communication system according to the present invention. FIG. 3A shows the configuration of the transmitter of the base station, and FIG. 3B shows the configuration of the receiver of the mobile station. FIG. 4 shows a frame configuration and reception timing used in the present invention.

図3Aの基地局の送信機が、図1Aに示す基地局の送信機
と異なる点は、多値レベル制御部304を有する点と、そ
れによって１次変調部303を制御し、例えば４値位相変
調から16値位相変調へと、多値変調の多値数を切換可能
とした点である。The difference between the transmitter of the base station of FIG. 3A and the transmitter of the base station shown in FIG. 1A is that the transmitter of the base station has a multi-level level controller 304 and thereby controls the primary modulation unit 303, The point is that the multilevel number of the multilevel modulation can be switched from modulation to 16-level phase modulation.

また、図3Bの移動局の受信機が、図1Bに示す基地局の
受信機と異なる点は、多値レベル制御部355を有する点
と、それによって復調部357を制御する点である。The receiver of the mobile station in FIG. 3B is different from the receiver of the base station shown in FIG.

このような構成において、通常モードにおいては、基
地局は送信する送信信号を４値位相変調する。しかし、
周辺基地局監視モードのときには、例えば16値位相変調
する。前者では２ビットで４つの変調状態の中のひとつ
の変調状態を表すが、後者では４ビットで16の変調状態
の中のひとつを表すことができる。したがって、移動局
における受信信号のレベル測定時に送信される16値変調
信号は、図４（Ａ）に示すように、フレームの半分の時
間だけ存在し、残りは変調信号のない空き時間となる。
すなわち、送信に空き時間が発生する。In such a configuration, in the normal mode, the base station performs quaternary phase modulation on a transmission signal to be transmitted. But,
In the peripheral base station monitoring mode, for example, 16-level phase modulation is performed. In the former, two bits represent one of four modulation states, while in the latter, four bits represent one of sixteen modulation states. Therefore, as shown in FIG. 4A, the 16-level modulated signal transmitted at the time of measuring the level of the received signal in the mobile station exists only for half the time of the frame, and the rest is the idle time without the modulated signal.
That is, idle time occurs in transmission.

こうすれば、移動局では通信を断することなく、図４
（Ｂ）に示すように、空き時間中に受信機の周波数を切
り替えて、周波数kfの周辺基地局の受信レベルを測定す
ることができる。In this way, the mobile station does not disconnect the communication,
As shown in (B), the frequency of the receiver is switched during the idle time, and the reception level of the peripheral base station at the frequency kf can be measured.

なお、監視モード期間中は、多値数を増加することに
ともなう信頼性の劣化を救済するために、基地局送信パ
ワーを増加させることもできる。During the monitoring mode, the transmission power of the base station can be increased to relieve the deterioration of reliability due to the increase in the number of multi-values.

第３実施例図1Aおよび1B、および図２で説明したレベル監視を行
う場合において、同様の装置を用いて通信中に基地局を
切り替えるハンドオフを図５−図８を用いて説明する。Third Embodiment In the case of performing the level monitoring described in FIGS. 1A and 1B and FIG. 2, a handoff for switching a base station during communication using a similar device will be described with reference to FIGS.

ハンドオフを行う場合のシステム構成を図５に示す。
いま、移動局504は通信中基地局502と通信している。そ
して、測定の結果、新基地局503のほうが測定結果がよ
く、新基地局503にハンドオフする必要が生じている。
この場合、通信中基地局502と新基地局503の上位局501
により制御されて、ハンドオフを行う。FIG. 5 shows a system configuration for performing a handoff.
Now, the mobile station 504 is communicating with the communicating base station 502. As a result of the measurement, the new base station 503 has a better measurement result, and it is necessary to perform handoff to the new base station 503.
In this case, the upper base station 501 of the communicating base station 502 and the new base station 503
To perform a handoff.

図６は、移動局504の送信部の構成を示すブロック図
である。この図において、符号60X（Ｘ＝１−８）は、
図1Aの符号10Xに対応する。FIG. 6 is a block diagram showing a configuration of the transmission unit of mobile station 504. In this figure, reference numeral 60X (X = 1-8) indicates
This corresponds to the symbol 10X in FIG. 1A.

この送信部が、図1Aに示す基地局の送信部と異なる点
は、副制御部620を有している点である。副制御部620
は、送信データ制御部622と、拡散符号切換部624と、周
波数切換部626とを有しおり、これら各部には、主制御
部609から制御情報が供給されている。送信データ制御
部622は、誤り訂正符号部602に信号を送り、図８（Ａ）
に示すように、１フレーム期間の間に、ユーザデータを
２回繰り返して出力するように制御する。これら２回の
繰り返しデータのうち、初めのデータは通信中基地局50
2に送信され、次のデータは新基地局503に送信される。
これに応じて、拡散符号切換部624は、拡散系列発生器6
04に信号を送り、拡散符号を切り換えるように制御する
とともに、周波数切換部626は、周波数変換部606に信号
を送り、その出力周波数を切り換えるように制御する。This transmitting section differs from the transmitting section of the base station shown in FIG. 1A in that it has a sub-control section 620. Sub-control unit 620
Has a transmission data control unit 622, a spreading code switching unit 624, and a frequency switching unit 626, and these units are supplied with control information from a main control unit 609. The transmission data control unit 622 sends a signal to the error correction code unit 602, and FIG.
As shown in (1), control is performed such that the user data is repeatedly output twice during one frame period. Of these two repetitions, the first data is the base station 50 during communication.
2 and the next data is transmitted to the new base station 503.
In response, spreading code switching section 624 provides
The signal is transmitted to the frequency conversion unit 606, and the frequency switching unit 626 controls the frequency conversion unit 606 to switch the output frequency.

なお、基地局の送信部および移動局の受信部は、図1A
および1Bに示す送信部および受信部の構成と同様であ
る。また、基地局の受信部は、図1Bに示す移動局の受信
部から、周波数切換部162と拡散符号切換部164を除いた
構成と同様である。The transmitting section of the base station and the receiving section of the mobile station are shown in FIG.
And 1B have the same configuration as the transmission unit and the reception unit. Further, the receiving unit of the base station has the same configuration as the receiving unit of the mobile station shown in FIG. 1B except that the frequency switching unit 162 and the spreading code switching unit 164 are removed.

図７は、ハンドオフ期間中の、通信中基地局502と新
基地局503の送信信号を示す。ハンドオフ期間中は、上
位局501の制御の下に、ハンドオフを行う２つの基地局5
02および503において、誤り訂正符号はせ生成せず、ユ
ーザデータ系列部分のみを変調して、通信中の基地局50
2と新基地局503の両方から送信するようにする。具体的
には、各基地局の主制御部109（図1A参照）は、上位局5
01からの指令に基づいて、誤り訂正符号部102をイネー
ブルまたはディスエーブルして、図７のタイミングでユ
ーザデータを送信する。FIG. 7 shows transmission signals of the communicating base station 502 and the new base station 503 during the handoff period. During the handoff period, two base stations 5 that perform handoff under the control of the upper station 501.
In 02 and 503, no error correction code is generated and only the user data sequence portion is modulated, and the base station 50 in communication is
2 and the new base station 503. Specifically, the main control unit 109 of each base station (see FIG. 1A)
Based on the command from 01, the error correction coding unit 102 is enabled or disabled, and user data is transmitted at the timing shown in FIG.

一方、移動局504では、フレームの途中で受信周波数
を切り替えて、通信中基地局502と新基地局503からの送
信信号を受信し復調する。そして、切換えたとき受信し
た２つの信号は図示しないメモリに蓄積し、読み出して
合成して符号判定する。このことにより、切換えたとき
においても信頼性の高いユーザデータを再生することが
できる。On the other hand, the mobile station 504 switches the reception frequency in the middle of the frame, and receives and demodulates transmission signals from the communicating base station 502 and the new base station 503. Then, the two signals received at the time of switching are stored in a memory (not shown), read out, combined, and code-determined. As a result, highly reliable user data can be reproduced even at the time of switching.

ハンドオフを行う場合の、移動局からの送信のタイミ
ングを図８に示す。移動局において、ユーザデータを１
次変調、２次変調して送信している。ハンドオフをする
場合、ハンドオフ期間は、誤り訂正符号は生成せず、ユ
ーザデータのみをフレームの途中で周波数を切換えて２
回送信している。その送信信号を図８（Ａ）に示してい
る。この場合、図８（Ｂ）に示すように、同じユーザデ
ータを送信周波数を切り替えて通信中基地局502と新基
地局503へ送信している。通信中基地局502および新基地
局503では送信信号をそれぞれ受信、復調し、符号判定
してそのデータを上位局501に伝送する。上位局501の再
生部510は、２つの復調信号のうちのどちらかを選択し
て、信頼性の高いユーザデータを再生する。このとき、
受信レベルの大きい方を選択する方法を用いることがで
きる。こうすることにより、受信品質を損なうことな
く、瞬断のないハンドオフが可能となる。あるいは、通
信中基地局502からの復調信号と、新基地局503からの復
調信号とを合成して、移動局からのユーザデータを再生
してもよい。FIG. 8 shows the timing of transmission from the mobile station when performing handoff. In the mobile station, the user data is set to 1
Secondary modulation and secondary modulation are transmitted. When handoff is performed, during the handoff period, no error correction code is generated, and only user data is switched in the middle of a frame by switching frequencies.
Has been sent times. The transmission signal is shown in FIG. In this case, as shown in FIG. 8B, the same user data is transmitted to the communicating base station 502 and the new base station 503 by switching the transmission frequency. The transmitting base station 502 and the new base station 503 receive and demodulate the transmission signal, judge the code, and transmit the data to the upper station 501. The reproducing unit 510 of the upper station 501 selects one of the two demodulated signals and reproduces highly reliable user data. At this time,
A method of selecting the higher reception level can be used. By doing so, it is possible to perform a handoff without instantaneous interruption without deteriorating the reception quality. Alternatively, the demodulated signal from the communicating base station 502 and the demodulated signal from the new base station 503 may be combined to reproduce the user data from the mobile station.

第４実施例図3A、3B、4Aおよび4Bで説明したレベル監視を行った
場合において、同様の装置を用いて通信中に基地局を切
り替えるハンドオフを、図５、図９および図10を用いて
説明する。図９は移動局の送信機の構成を示し、図10は
ハンドオフのタイミングを示している。Fourth Embodiment In the case where the level monitoring described in FIGS. 3A, 3B, 4A, and 4B is performed, a handoff for switching a base station during communication using a similar device will be described with reference to FIGS. 5, 9, and 10. explain. FIG. 9 shows the configuration of the transmitter of the mobile station, and FIG. 10 shows the timing of handoff.

図９は、移動局504の送信部の構成を示すブロック図
である。この図において、符号90X（Ｘ＝１−９）は、
図3Aの符号30Xに対応する。FIG. 9 is a block diagram showing the configuration of the transmission unit of mobile station 504. In this figure, reference numeral 90X (X = 1-9) indicates
This corresponds to reference numeral 30X in FIG. 3A.

この送信部が、図3Aに示す基地局の送信部と異なる点
は、副制御部920を有している点である。副制御部920
は、多値数切換部922と、拡散符号切換部924と、周波数
切換部926とを有しており、これら各部には、フレーム
構成部901から制御情報が供給されている。多値数切換
部922は、多値レベル制御部904に信号を送り、多値数を
制御する。すなわち、通常モードでは、１フレーム期間
にユーザデータと誤り訂正チェックビットとを出力し、
ハンドオフモードでは、図10に示すように、1/2フレー
ム期間に、ユーザデータと誤り訂正チェックビットとを
出力するように、多値数を制御する。これに応じて、拡
散符号切換部924は、拡散系列発生器906に信号を送り、
拡散符号を切り換えるように制御するとともに、周波数
切換部926は、周波数変換部908に信号を送り、その出力
周波数を切り換えるように制御する。This transmitting section differs from the transmitting section of the base station shown in FIG. 3A in that it has a sub-control section 920. Sub-control unit 920
Has a multi-level number switching unit 922, a spreading code switching unit 924, and a frequency switching unit 926, and control information is supplied to these units from the frame configuration unit 901. The multi-level switching unit 922 sends a signal to the multi-level control unit 904 to control the multi-level. That is, in the normal mode, the user data and the error correction check bit are output during one frame period,
In the handoff mode, as shown in FIG. 10, a multi-valued number is controlled so that user data and an error correction check bit are output in a 1/2 frame period. In response, spreading code switching section 924 sends a signal to spreading sequence generator 906,
In addition to controlling to switch the spreading code, frequency switching section 926 sends a signal to frequency conversion section 908 and controls to switch the output frequency.

なお、基地局の送信部および移動局の受信部は、図3A
および3Bに示す送信部および受信部の構成と同様であ
る。また、基地局の受信部は、図3Bに示す移動局の受信
部から、周波数切換部362と拡散符号切換部364を除いた
構成と同様である。The transmitting unit of the base station and the receiving unit of the mobile station are shown in FIG.
And 3B have the same configuration as the transmission unit and the reception unit. Further, the receiving unit of the base station has the same configuration as that of the receiving unit of the mobile station shown in FIG. 3B except that frequency switching unit 362 and spreading code switching unit 364 are omitted.

さて、本実施例におけるハンドオフは、１次変調の多
値数を変えて行う。通信中基地局502及び新基地局503の
双方は、ハンドオフを行う期間中、上位局501の制御の
下に、図10に示したように、１次変調の多値数を変えて
空き時間を作り出す。ここで、第３実施例の場合のハン
ドオフとは異なり、誤り訂正符号を除く必要はなく、ユ
ーザデータ＋誤り訂正チェックビットを送信する。The handoff in the present embodiment is performed by changing the multi-level number of the primary modulation. During the handoff period, both the communicating base station 502 and the new base station 503 change the multilevel value of the primary modulation to increase the idle time under the control of the upper station 501 as shown in FIG. produce. Here, unlike the handoff in the third embodiment, there is no need to remove the error correction code, and user data + error correction check bits are transmitted.

移動局504では、上記のハンドオフ期間に受信する局
を切換える。受信側では、１フレームの途中で受信周波
数を切り替えてハンドオフを行う。そして、切換えた２
つの基地局502,503の信号を受信復調し、復調した信号
を図示しないメモリに蓄積し、読み出して合成する。そ
して、１フレームの信号として、誤り訂正復号し、送信
データを再生することができる。The mobile station 504 switches the receiving station during the above handoff period. On the receiving side, handoff is performed by switching the receiving frequency in the middle of one frame. And 2 which switched
The signals of the two base stations 502 and 503 are received and demodulated, and the demodulated signals are stored in a memory (not shown), read, and combined. Then, as a signal of one frame, error correction decoding can be performed, and transmission data can be reproduced.

一方、移動局504における送信側のハンドオフすると
き、移動局504は変調の多値数を変更して送信データを
変調し、送信する周波数を１フレームの途中で切換え、
２回送信する。ハンドオフ対象の双方の基地局502,503
では、受信した信号を誤り訂正復号し、送信データを再
生して上位局501に転送する。上位局501では、通信中の
基地局と新基地局で受信再生したデータのどちらかを選
択する。このとき、例えば受信レベルの大きい方を選択
すればよい。On the other hand, when handing off the transmitting side in the mobile station 504, the mobile station 504 modulates the transmission data by changing the multi-level number of modulation, and switches the transmission frequency in the middle of one frame.
Send twice. Both base stations 502 and 503 to be handed off
Then, the received signal is subjected to error correction decoding, the transmission data is reproduced, and transferred to the upper station 501. The upper station 501 selects either the base station in communication or the data received and reproduced by the new base station. At this time, for example, one having a higher reception level may be selected.

第５実施例図1A、1B、および２で説明した測定を用いた場合にお
いて、同様の装置を用いて通信中に基地局を切り替える
ハンドオフの他の方式を図５および図11を用いて説明す
る。図11は、ハンドオフを行うときの基地局の送信のタ
イミングを示す。Fifth Embodiment In the case where the measurement described in FIGS. 1A, 1B, and 2 is used, another method of handoff for switching a base station during communication using a similar device will be described with reference to FIGS. . FIG. 11 shows the transmission timing of the base station when performing handoff.

この場合の、基地局の送信機および移動局の受信機
は、図1Aおよび1Bに示すものと同様である。また、移動
局の送信機および基地局の受信機も、図1Aおよび1Bに示
すものと同様である。In this case, the transmitter of the base station and the receiver of the mobile station are the same as those shown in FIGS. 1A and 1B. Also, the transmitter of the mobile station and the receiver of the base station are the same as those shown in FIGS. 1A and 1B.

通信中の基地局502は、図11に示すように、ハンドオ
フ期間中上位局501の制御により誤り訂正符号は生成せ
ず、ユーザデータ系列部分のみを変調して送信する。新
基地局503からは、誤り訂正符号化チェックビットのみ
を変調して送信をする。As shown in FIG. 11, the communicating base station 502 does not generate an error correction code under the control of the upper station 501 during the handoff period, and modulates and transmits only the user data sequence portion. From the new base station 503, only the error correction coded check bits are modulated and transmitted.

移動局504は、フレームの途中で受信周波数を切り替
えて、通信中の基地局502からのユーザデータと新基地
局503からの誤り訂正符号化チェックビットを受信す
る。そして、双方の基地局からのデータをメモリに記憶
し、読み出して合成して、もとのデータを再生する。新
基地局503から誤り訂正符号化チェックビットを受信し
ているので、合成した１フレームのデータに対して誤り
訂正復号ができ、より信頼性の高い送信データを再生す
ることができる。The mobile station 504 switches the reception frequency in the middle of the frame and receives the user data from the communicating base station 502 and the error correction coded check bits from the new base station 503. Then, the data from both base stations is stored in the memory, read out and combined, and the original data is reproduced. Since the error correction coding check bits are received from the new base station 503, error correction decoding can be performed on the combined data of one frame, and more reliable transmission data can be reproduced.

第６実施例図1A、1B、および２で説明した測定を用いた場合にお
いて、同様の装置を用いて通信中に基地局を切り替える
ハンドオフのさらに他の方式を図５におよび図12を用い
て説明する。図12は、ハンドオフを行うときの移動局の
送信のタイミングを示す。Sixth Embodiment In the case of using the measurement described in FIGS. 1A, 1B, and 2, still another method of handoff for switching a base station during communication using a similar device will be described with reference to FIGS. 5 and 12. explain. FIG. 12 shows transmission timing of the mobile station when performing handoff.

この場合の、基地局の送信機および移動局の受信機
は、図1Aおよび1Bに示すものと同様である。また、移動
局の送信機および基地局の受信機は、図６に示す送信機
および図1Bに示す受信機と同様である。In this case, the transmitter of the base station and the receiver of the mobile station are the same as those shown in FIGS. 1A and 1B. Further, the transmitter of the mobile station and the receiver of the base station are the same as the transmitter shown in FIG. 6 and the receiver shown in FIG. 1B.

移動局504は、図12に示すように、ハンドオフ期間中
には、ユーザデータと誤り訂正チェックビットとを変調
して交互に送信する。すなわち、フレーム前半部では、
通信中基地局502の受信周波数foでユーザデータを送信
し、フレーム後半部では、新基地局503の受信周波数fk
で誤り訂正チェックビットを送信する。As shown in FIG. 12, the mobile station 504 modulates user data and error correction check bits and transmits them alternately during the handoff period. That is, in the first half of the frame,
The user data is transmitted at the reception frequency fo of the communicating base station 502, and the reception frequency fk of the new base station 503 is transmitted in the latter half of the frame.
Transmits the error correction check bit.

通信中基地局502は、フレーム前半部のユーザデータ
を受信し、新基地局503は、フレーム後半部の誤り訂正
符号化チェックビットを受信する。そして、上位局501
の再生部510は、双方の基地局からのデータをメモリに
記憶し、読み出して合成して、もとのデータを再生す
る。この場合、上位局501は、新基地局503からの誤り訂
正符号化チェックビットを受信しているので、合成した
１フレームのデータに対して誤り訂正復号ができ、より
信頼性の高い送信データを再生することができる。The communicating base station 502 receives the user data in the first half of the frame, and the new base station 503 receives the error correction coding check bits in the second half of the frame. And the upper station 501
The reproducing unit 510 stores data from both base stations in the memory, reads out and combines the data, and reproduces the original data. In this case, since the upper station 501 has received the error correction coding check bit from the new base station 503, the upper station 501 can perform error correction decoding on the combined one frame data, and transmit more reliable transmission data. Can be played.

Claims

(57) [Claims]

A first base station performs error correction coding on user data, and then converts a narrowband modulation signal obtained by primary-modulating the user data and error correction check bits into a wideband signal using a spreading code. Then, the mobile station transmits
In the CDMA mobile communication method for converting the wideband signal to a narrowband modulation signal, demodulating, error correcting and decoding, and reproducing the user data, the mobile station transmits the user transmitted from the first base station. Demodulating the user data at a first time during data reception; and suspending the error correction decoding process at a second time during reception of the error correction check bits, the user data not performing error correction decoding. And switching the receiving frequency to the radio frequency of the second base station having a different operating frequency from the first base station at the second time, so that the reception level of the second base station is changed. Monitoring a CDMA mobile communication method.

2. The CDMA mobile communication method according to claim 1, wherein during a handoff period between said first base station and said second base station, said first base station comprises: Transmitting the user data at a first time and suspending the transmission at the second time; and transmitting the user data at the second time at the second base station; Suspending the transmission at the time of, and the mobile station receives and demodulates the signal from the first base station at the first time, and the frequency of the second base station at the second time. Switching the frequency of the receiver, receiving and demodulating the signal from the second base station, combining the signal from the first base station and the signal from the second base station, and converting the user data. Regenerating a CDMA mobile communication method.

3. The CDMA mobile communication method according to claim 2, wherein during the handoff period, the mobile station transmits user data to the first base station at a third time when user data is to be transmitted. A fourth radio frequency to transmit to the station and transmit error correction check bits
The user data to the second base station for a second time
Transmitting at the first base station, demodulating the user data received at the third time, and receiving at the fourth time at the second base station. Demodulating the user data, and regenerating the user data by combining the demodulated signals in an upper station of the first base station and the second base station. CDMA mobile communication method.

4. The CDMA mobile communication method according to claim 1, wherein, during a handoff period between said first base station and said second base station, said first base station comprises: Transmitting the user data at a first time, suspending the transmission at the second time; and transmitting the error correction check bit at the second time at the second base station, Suspending the transmission at a first time, wherein the mobile station receives and demodulates a signal from the first base station at the first time, and the second base station at the second time The frequency of the receiver is switched to the radio frequency of
Receiving and demodulating a signal from the base station, and reproducing the user data using the user data from the first base station and the error correction check bit from the second base station. CDMA mobile communication method.

5. The CDMA mobile communication method according to claim 4, wherein, during the handoff period, the mobile station transmits user data to the first base station at a third time when user data is to be transmitted. A fourth radio frequency to transmit to the station and transmit error correction check bits
Transmitting an error correction check bit to the second base station at a second radio frequency at a time of; and demodulating the user data received at the third time at the first base station. A step of demodulating the error correction check bits received at the fourth time in the second base station; and a step of demodulating the error correction check bits received in the higher order station in the first base station and the second base station. Recovering the user data by performing error correction decoding using a signal.

6. A first base station, after error correction coding of user data, performs spread code on a narrow band modulation signal obtained by performing primary modulation by multi-level modulation on the user data and error correction check bits. In the CDMA mobile communication method, the mobile station converts the wideband signal into a narrowband modulated signal, demodulates the error, and performs error correction decoding processing to reproduce the user data. During a reception level monitoring period in which a mobile station monitors a reception level of a signal from a second base station different from the first base station, the first base station includes the user data and an error correction check bit. Creating a second time to suspend transmission by increasing the multi-level number of the multi-level modulation at a first time; and wherein the mobile station performs the multi-level modulation at the first time. Multi-level value modulation And demodulate the received signal, perform error correction decoding processing, and reproduce the user data.At the second time, switch the reception frequency to the radio frequency of the second base station. Monitoring the reception level of the second base station.

7. The CDMA mobile communication method according to claim 6, wherein during the handoff period between said first base station and said second base station, said first base station comprises: Transmitting the user data and its error correction check bit at the first time; transmitting the user data and its error correction check bit at the second time at the second base station; The mobile station receives the user data and the error correction check bit from the first base station at the first time, and changes a reception frequency at the second time to a radio frequency of the second base station. Switching to a frequency, receiving the user data and the error correction check bit, and combining the signal from the first base station and the signal from the second base station to reproduce the user data A CDMA mobile communication method, comprising:

8. After error correction coding of user data,
A first base station that performs secondary modulation of a narrowband modulated signal obtained by primary-modulating the user data and the error correction check bit into a wideband signal with a spreading code and transmits the wideband signal to a narrowband modulated signal; A mobile station that converts, demodulates, and performs error correction decoding processing to reproduce the user data.
In the CDMA mobile communication system, the mobile station includes: a demodulation unit that demodulates the user data at a first time during reception of the user data transmitted from the first base station; An error correction decoding unit that suspends the error correction decoding process at a second time, and outputs the user data that is not subjected to the error correction decoding; and, at the second time, sets a reception frequency to the first base station. CDMA comprising: frequency switching means for switching to a radio frequency of a second base station having a different operating frequency; and a reception level measuring unit for monitoring a reception level of a signal from the second base station. Mobile communication system.

9. The CDMA mobile communication system according to claim 8, further comprising: an upper station instructing a handoff between said first base station and said second base station; The base station, based on a handoff command from the upper station, transmits the user data at the first time, and includes first control means for suspending transmission at the second time, 2 base stations, based on the handoff command,
Transmitting the user data at the second time;
The mobile station further comprises a second control unit for suspending the transmission at the time, wherein the mobile station switches a reception frequency to one of the transmission frequency of the first base station and the second transmission frequency. Means for receiving and demodulating a signal from the first base station at the first time and receiving and demodulating a signal from the second base station at the second time; A CDMA mobile communication system comprising: a demodulation unit that combines a signal from the second base station with a signal from the second base station to reproduce user data.

10. The CDMA mobile communication system according to claim 9, wherein said mobile station sets a transmission frequency of a transmitter to a reception frequency of said first base station and a reception frequency of said second base station. Transmission frequency switching means for switching to one of the following, and during a handoff period, at a third time when user data is to be transmitted, user data is transmitted at the reception frequency of the first base station, and an error correction check bit is to be transmitted. And transmitting means for transmitting the user data at a reception frequency of the second base station at a fourth time, wherein the first base station demodulates the user data received at the third time. A first demodulation unit, the second base station includes a second demodulation unit for demodulating the user data received at the fourth time, Demodulated demodulated signal CDMA mobile communication system characterized by comprising means for reproducing the user data by combining.

11. The CDMA mobile communication system according to claim 8, further comprising: an upper station instructing a handoff between said first base station and said second base station; The base station, based on a handoff command from the upper station, transmits the user data at the first time, and includes first control means for suspending transmission at the second time, 2 base stations, based on the handoff command,
The mobile station further comprises a second control unit for transmitting the error correction check bit at the second time and suspending the transmission at the first time, wherein the mobile station sets a frequency of a receiver to the first base station. Receiving frequency switching means for adjusting to one of a transmission frequency of a station and the second transmission frequency, and receiving and demodulating a signal from the first base station at the first time; A demodulator that receives and demodulates a signal from the second base station, and reproduces the user data using the user data from the first base station and the error correction check bit from the second base station. A CDMA mobile communication system, comprising:

12. The CDMA mobile communication system according to claim 11, wherein said mobile station sets a transmission frequency of a transmitter to a reception frequency of said first base station and a reception frequency of said second base station. Transmission frequency switching means for switching to one of the following: transmitting the user data at the reception frequency of the first base station and transmitting an error correction check bit at a third time during which the user data is to be transmitted during the handoff period. And transmitting means for transmitting an error correction check bit at a receiving frequency of the second base station at a fourth time to be transmitted, wherein the first base station receives the user data at the third time. The second base station includes a demodulation unit that demodulates the error correction check bit received at the fourth time, and the upper station outputs an output from each of the demodulation units. Is A CDMA mobile communication system comprising means for reproducing the user data by performing error correction decoding using the demodulated signal.

13. A narrowband modulated signal obtained by subjecting user data and error correction check bits to primary modulation by multi-level modulation after error correction encoding of user data, and secondary-modulating the narrowband modulated signal to a wideband signal by a spread code. A CDMA mobile communication system comprising a first base station for transmitting and transmitting, and a mobile station for converting the wideband signal to a narrowband modulated signal, demodulating, performing error correction decoding, and reproducing the user data, A first multi-level control unit for changing a multi-level number of the multi-level modulation of the user data and the error correction check bit; and the mobile station, the first base station During the reception level monitoring period for monitoring the reception level of the signal from the second base station different from the second time, the multi-level number is increased and transmitted at the first time, so that the transmission is paused for the second time. Means of making Comprising: receiving frequency switching means for adjusting a frequency of a receiver to one of a transmitting frequency of the first base station and the second transmitting frequency; and changing a multi-level number of the multi-level modulation. A second multi-level control unit for causing the multi-level number to be increased at the first time, demodulating a received signal, performing error correction decoding processing, and reproducing the user data; And a reception level measuring unit for monitoring a reception level of the second base station by switching a reception frequency to a transmission frequency of the second base station at time 2.
MA mobile communication system.

14. The CDMA mobile communication system according to claim 13, further comprising an upper station instructing a hand-off between said first base station and said second base station, The base station includes a first transmitting unit that transmits the user data and the error correction check bit thereof at the first time based on a handoff command from the upper station, The second base station includes: Based on the handoff command,
The mobile station further comprises second transmitting means for transmitting the user data and the error correction check bit thereof at the second time, wherein the mobile station transmits the user data and the user data from the first base station at the first time. While receiving the error correction check bit, the receiving frequency is switched to the transmission frequency of the second base station at the second time to receive the user data and the error correction check bit, and from the first base station, A CDMA mobile communication system comprising: means for combining a signal and a signal from the second base station to reproduce the user data.

15. A first base station for performing second-order modulation of a narrow-band modulated signal obtained by subjecting user data to error-correction encoding and then primary modulation to a wide-band signal with a spreading code, and transmitting the wide-band signal. A mobile station for converting to a narrowband modulated signal, demodulating, error correcting and decoding, and reproducing the user data.
A mobile station in a CDMA mobile communication system, wherein the receiver of the mobile station comprises: a demodulation unit that demodulates the user data at a first time during reception of the user data transmitted from the first base station. An error correction decoding unit that suspends the error correction decoding process at a second time during reception of the error correction check bit and outputs the user data that is not subjected to error correction decoding; and a reception frequency at the second time. A frequency switching unit that switches to a radio frequency of a second base station having a different operating frequency from the first base station, and a reception level measurement unit that monitors a reception level of the second base station. A mobile station characterized by the following.

16. The mobile station according to claim 15, wherein the receiver of the mobile station determines a reception frequency of a transmission frequency of the first base station and a transmission frequency of the second base station. A reception frequency switching unit adapted to one of the first base station and a handoff period between the first base station and the second base station, for receiving and demodulating a signal from the first base station at the first time; The second time at the second time
And a demodulation unit for receiving and demodulating a signal from the base station, combining a signal from the first base station and a signal from the second base station, and reproducing user data. A transmission frequency switching unit that adjusts a transmission frequency to a reception frequency of the first base station and a reception frequency of the second base station; and a third to transmit user data during the handoff.
At the time, the user data is transmitted at the reception frequency of the first base station, and the user data is transmitted at the reception frequency of the second base station at a fourth time at which an error correction check bit is to be transmitted. The first base station demodulates the user data received at the third time; and the second base station transmits the user data received at the fourth time. A mobile station, comprising: a step of demodulating; and a step of reproducing the user data by combining demodulated signals in an upper station of the first base station and the second base station. .

17. A narrowband modulated signal obtained by performing primary modulation by multi-level modulation on user data and error correction check bits after error correction coding of user data, and secondary-modulating the narrowband modulated signal with a spreading code to a wideband signal. A first base station that converts the wideband signal into a narrowband modulation signal, demodulates the error signal, and performs error correction decoding processing to reproduce the user data. A mobile station in a CDMA mobile system, wherein the user data and the error correction check bits are transmitted at a first time by increasing the multi-level number of the multi-level modulation, thereby creating a second time for pausing transmission. A receiver of the mobile station, wherein the mobile station monitors a reception level of a signal from a second base station different from the first base station during a reception level monitoring period. One hour Wherein the multi-level number switching unit to increase the multi-level number of the multi-level modulation, in the first time, the demodulated user data and error correction check bits, and error correction decoding process,
Means for reproducing the user data; a reception frequency switching unit for adjusting a reception frequency of the receiver to one of a transmission frequency of the first base station and a transmission frequency of the second base station; A reception level measuring unit for monitoring a reception level of the second base station during time.

18. The mobile station according to claim 17, wherein a reception frequency switching unit of a receiver of said mobile station comprises a handoff period between said first base station and said second base station. In the meantime, the reception frequency is switched to the transmission frequency of the first base station during the first time, and the transmission frequency is switched to the transmission frequency of the second base station during the second time. A mobile station for reproducing the user data by combining a signal from the first base station and a signal from the second base station.