JPH0629948A - Synchronization tracking circuit - Google Patents
Synchronization tracking circuitInfo
- Publication number
- JPH0629948A JPH0629948A JP4206037A JP20603792A JPH0629948A JP H0629948 A JPH0629948 A JP H0629948A JP 4206037 A JP4206037 A JP 4206037A JP 20603792 A JP20603792 A JP 20603792A JP H0629948 A JPH0629948 A JP H0629948A
- Authority
- JP
- Japan
- Prior art keywords
- manchester code
- phase
- signal
- dll
- inverse spread
- 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.)
- Pending
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- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
- Dc Digital Transmission (AREA)
Abstract
Description
【０００１】[0001]
【産業用の利用分野】本発明はスペクトル拡散通信方式
に於ける同期追従回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous tracking circuit in a spread spectrum communication system.
【０００２】[0002]
【従来技術】スペクトル拡散通信方式は広い周波数帯域
に信号を拡散して伝送するため、単位ヘルツ当たりの電
力が小さく他の通信への妨害を与えることが少ないのみ
ならず雑音や伝送路特性の変動の影響を受けにくい特徴
を有していることから、近年多用されつつある。このス
ペクトル拡散通信方式では、送信側に於ける拡散用及び
受信側に於ける逆拡散用のＰＮ符号（疑似雑音信号）と
しては図２に示すように自己相関特性の良好なＭ系列を
（同図に於いて、横軸はＭ系列の位相ずれを、ＴｃはＭ
系列のチップ周期を表す）使用することが多く、又送信
側と受信側とのＭ系列の位相を一致させる、即ち同期を
とる必要がある。このための同期追従回路としては、比
較的簡単な回路構成で同期追従特性が良いことから、一
般にＤｅｌａｙ ＬｏｃｋＬｏｏｐ回路（以下、ＤＬＬ
と称する）が良く用いられる。2. Description of the Related Art In a spread spectrum communication system, a signal is spread and transmitted in a wide frequency band, so that the power per unit hertz is small and interference with other communication is small, and noise and fluctuations in transmission line characteristics are caused. In recent years, it has been widely used because it has a characteristic that it is not easily affected by. In this spread spectrum communication system, as a PN code (pseudo noise signal) for spreading on the transmitting side and for despreading on the receiving side, as shown in FIG. In the figure, the horizontal axis is the phase shift of the M series, and Tc is M
(Which represents the chip cycle of the sequence) is often used, and the phases of the M sequences of the transmitting side and the receiving side must be matched, that is, synchronized. As a synchronization follow-up circuit for this purpose, a delay lock loop circuit (hereinafter, DLL) is generally used because it has a relatively simple circuit configuration and good synchronization follow-up characteristics.
Is called) is often used.
【０００３】以下、このＤＬＬを用いたベースバンドス
ペクトル拡散受信機を図３に示すブロック図を参照して
説明する。同図に於いて、Ｍ０は逆拡散用のＭ系列であ
って、Ｍ系列ＭＥはＭ系列Ｍ０よりも０．５チップ分位
相の進んだＭ系列であり、Ｍ系列ＭＬはＭ系列Ｍ０より
も０．５チップ分位相の遅れたＭ系列で、このようなＭ
系列を使用するＤＬＬは「１Δ−ＤＬＬ」と呼ばれる。
又、ＤＬＬは送信側から送られたスペクトル拡散信号に
対してＭ系列ＭＥ及びＭ系列ＭＬを夫々乗積して求めた
各相関値の絶対値を相互に引き算を行って図４の実線に
示すような出力波形、所謂Ｓカーブを得る。ここで、絶
対値をとるのは受信したＭ系列に乗積されているデータ
によって自己相関の極性が変わり、図４の点線に示すよ
うにＳカーブの傾きが逆になるのを防ぐためである。A baseband spread spectrum receiver using this DLL will be described below with reference to the block diagram shown in FIG. In the figure, M0 is an M sequence for despreading, M sequence ME is an M sequence that is 0.5 chips ahead of M sequence M0 in phase, and M sequence ML is more than M sequence M0. This is an M series with a phase delay of 0.5 chip
A DLL that uses a sequence is called "1Δ-DLL".
Further, the DLL performs mutual subtraction of the absolute values of the respective correlation values obtained by multiplying the spread spectrum signal sent from the transmission side by the M series ME and the M series ML, and shows the solid line in FIG. Such an output waveform, so-called S curve, is obtained. Here, the absolute value is taken in order to prevent the polarity of the autocorrelation from changing depending on the received data multiplied by the M sequence, and preventing the slope of the S curve from being reversed as shown by the dotted line in FIG. .
【０００４】更に、ＤＬＬはそのＳカーブを制御電圧と
して前記各Ｍ系列の基準クロック発生用電圧制御発振回
路ＶＣＯに印加することにより基準クロックの周波数を
制御し、前記Ｍ系列Ｍ０の位相を送信側の拡散用Ｍ系列
の位相に同期させていた。従って、ＤＬＬの性能はＳカ
ーブの形状によって決まり、これに要求される条件とし
ては、（１）原点近傍での傾きが大であること、（２）
原点を除く原点近傍のなるべく広い範囲で絶対値が大で
あること、等が挙げられる。Further, the DLL controls the frequency of the reference clock by applying the S curve as a control voltage to the voltage control oscillation circuit VCO for generating the reference clock of each M series, and the phase of the M series M0 is transmitted. It was synchronized with the phase of the spreading M series. Therefore, the performance of the DLL is determined by the shape of the S curve, and the conditions required for this are (1) a large inclination near the origin, (2)
The absolute value is large in as wide a range as possible near the origin, excluding the origin.
【０００５】上述したような拡散符号としてＭ系列を用
いたスペクトル拡散通信方式では上記の条件を満足して
いるが、図５の実線に示すようにＭ系列には直流近傍の
周波数成分が多いため、送受信間を結ぶ伝送路の直流近
傍の周波数特性が劣悪な場合、又はその伝送路に対しス
ペクトル拡散通信と直流信号伝送との兼用を希望する場
合、各Ｍ系列で逆拡散した信号のレベルが劣化するか
ら、図５の点線に示すように直流近傍の周波数成分が小
さなマンチェスタ符号を用いるのが一般的である。即
ち、図６に示すようにＭ系列を所定のクロック信号に掛
け算したものを前記Ｍ系列に替えて使用する手段が考え
られる。しかしながら、マンチェスタ符号の自己相関特
性は図７（ａ）に示すようにサイドローブを持ち、Ｓカ
ーブは図７（ｂ）に示すようにその原点近傍で傾斜が逆
になるから、ＤＬＬの同期追従特性が大幅に劣化すると
いう問題があった。The above-mentioned condition is satisfied in the spread spectrum communication system using the M series as the spread code as described above, but the M series has many frequency components near DC as shown by the solid line in FIG. , If the frequency characteristics near the direct current of the transmission line connecting the transmitter and the receiver are poor, or if it is desired to use both spread spectrum communication and DC signal transmission for that transmission line, the level of the despread signal in each M series is Since it deteriorates, it is common to use a Manchester code having a small frequency component near DC as shown by the dotted line in FIG. That is, as shown in FIG. 6, a means of using a product obtained by multiplying a M-sequence by a predetermined clock signal instead of the M-sequence can be considered. However, the autocorrelation characteristic of the Manchester code has a side lobe as shown in FIG. 7A, and the S curve has a reverse slope near its origin as shown in FIG. There is a problem that the characteristics are significantly deteriorated.
【０００６】[0006]
【発明の目的】本発明は上述したような従来のＤＬＬの
問題を解決するためになされたものであって、伝送路の
直流近傍の周波数特性が劣悪な場合、又は伝送路に対し
スペクトル拡散通信と直流信号伝送との兼用を希望する
場合にマンチェスタ符号を使用しても同期追従を正常に
行うことが可能なＤＬＬを提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional DLL as described above, and when the frequency characteristic near the direct current of the transmission line is poor, or the spread spectrum communication is performed on the transmission line. It is an object of the present invention to provide a DLL that can normally perform synchronous tracking even if Manchester code is used when it is desired to combine the use of DC code and DC signal transmission.
【０００７】[0007]
【発明の概要】上述の目的を達成するため、本発明に於
いては以下のように構成する。即ち、逆拡散用マンチェ
スタ符号よりも位相が同一チップ分進んだマンチェスタ
符号及び遅れたマンチェスタ符号夫々で逆拡散した信号
夫々の差分信号レベルに比例して前記逆拡散用マンチェ
スタ符号の位相を制御し、その位相を送信側のマンチェ
スタ符号の位相に同期させる手段に於いて、前記逆拡散
用マンチェスタ符号で逆拡散した信号を２値化して求め
た＋１又は−１の状態信号を前記差分信号に掛け合わせ
て求めた信号レベルに比例して逆拡散用マンチェスタ符
号の位相を制御するように構成する。SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is configured as follows. That is, the phase of the despreading Manchester code is controlled in proportion to the differential signal level of the despread signals of the Manchester code and the delayed Manchester code whose phases are advanced by the same chip as the despreading Manchester code. In the means for synchronizing the phase with the phase of the Manchester code on the transmission side, the differential signal is multiplied by the status signal of +1 or -1 obtained by binarizing the signal despread by the Manchester code for despreading. The phase of the Manchester code for despreading is controlled in proportion to the obtained signal level.
【０００８】[0008]
【実施例】以下、本発明を図面に示した実施例に基づい
て詳細に説明する。図１は本発明に係るＤＬＬを具えた
スペクトル拡散受信機の一実施例を示す構成図である。
同図に於いて符号１はスペクトル拡散受信機であって、
そのスペクトル拡散受信機１は図示を省略した送信側と
同一のマンチェスタ符号Ｐ０、その符号Ｐ０よりも０．
５チップ分位相が進んだマンチェスタ符号ＰＥ及び符号
Ｐ０よりも０．５チップ分位相が遅れたマンチェスタ符
号ＰＬ各々を発生する拡散符号発生器２を具えたＤＬＬ
３を設ける。又、スペクトル拡散受信機１は前記送信側
から送致されたスペクトル拡散信号Ｓを増幅器４に供給
すると共に、乗算器５によりその増幅信号を前記マンチ
ェスタ符号Ｐ０で逆拡散し、その逆拡散信号をローパス
フィルタ６を介してデータ復調器７に供給し、その出力
端から元のデータを復調するように接続する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings. FIG. 1 is a block diagram showing an embodiment of a spread spectrum receiver including a DLL according to the present invention.
In the figure, reference numeral 1 is a spread spectrum receiver,
The spread spectrum receiver 1 has the same Manchester code P0 as that of the transmitting side (not shown), which is 0.
A DLL including a spreading code generator 2 for generating a Manchester code PE having a phase advanced by 5 chips and a Manchester code PL having a phase delayed by 0.5 chip from the code P0.
3 is provided. Further, the spread spectrum receiver 1 supplies the spread spectrum signal S sent from the transmitting side to the amplifier 4, and the multiplier 5 despreads the amplified signal with the Manchester code P0, and the despread signal is low-passed. The data is supplied to the data demodulator 7 through the filter 6, and the output terminal thereof is connected so as to demodulate the original data.
【０００９】一方、前記ＤＬＬ３は乗算器８により前記
増幅信号をマンチェスタ符号ＰＥで逆拡散し、その逆拡
散信号をローパスフィルタ９を介して加算器１０の＋端
子に供給すると共に、乗算器１１により前記増幅信号を
マンチェスタ符号ＰＬで逆拡散し、その逆拡散信号をロ
ーパスフィルタ１２を介して前記加算器１０の−端子に
供給する。又、ＤＬＬ３は加算器１０の出力端を乗算器
１３の一方の入力端に接続すると共に、前記ローパスフ
ィルタ６の出力端を２値化回路１４を介して前記乗算器
１３の他方の入力端に接続し、その出力端をループフィ
ルタ１５及び前記各マンチェスタ符号の基準クロックを
発生するための電圧制御発振回路（以下、ＶＣＯと称す
る）１６を介して前記拡散符号発生器２の制御端子に接
続し、送信側のマンチェスタ符号と前記マンチェスタ符
号Ｐ０との同期をとった後にその状態を保持するように
構成する。On the other hand, the DLL 3 despreads the amplified signal with the Manchester code PE by the multiplier 8, supplies the despread signal to the + terminal of the adder 10 through the low-pass filter 9, and the multiplier 11 also. The amplified signal is despread with the Manchester code PL, and the despread signal is supplied to the-terminal of the adder 10 via the low-pass filter 12. The DLL 3 connects the output terminal of the adder 10 to one input terminal of the multiplier 13 and connects the output terminal of the low-pass filter 6 to the other input terminal of the multiplier 13 via the binarization circuit 14. The output terminal is connected to the control terminal of the spread code generator 2 via a loop filter 15 and a voltage controlled oscillator circuit (hereinafter referred to as VCO) 16 for generating a reference clock for each Manchester code. , The transmission-side Manchester code and the Manchester code P0 are synchronized and then held in that state.
【００１０】このように構成する受信機１は以下のよう
に動作する。即ち、受信機１はスペクトル拡散信号Ｓを
受信した際に、ＤＬＬ３が加算器１０を使用してローパ
スフィルタ９の出力信号からローパスフィルタ１２の出
力信号を差し引いて図８の点線に示すようなＳカーブε
ｐを生成すると共に、２値化回路１４を使用してローパ
スフィルタ６の出力信号を２値化して＋１又は−１の状
態値を生成し、乗算器１３から図８の実線に示すような
Ｓカーブεａを生成する。又、ＤＬＬ３はＳカーブεａ
をループフィルタ１５により制御電圧とし、その電圧値
に比例して前記ＶＣＯ１６の基準クロック周波数を制御
する。ここで、Ｓカーブεａは前記図７（ｂ）に示すよ
うな従来のＤＬＬに於けるＳカーブのように、その原点
近傍で傾斜が逆にならずその傾きが大きいから、ＶＣＯ
１６はマンチェスタ符号Ｐ０の位相と送信側のマンチェ
スタ符号の位相とを正確に同期させると共に、その同期
状態を保持するように発振クロックを制御することがで
き、スペクトル拡散受信機１はデータ復調器７から元の
データを正常に復調することができる。The receiver 1 configured as described above operates as follows. That is, when the receiver 1 receives the spread spectrum signal S, the DLL 3 subtracts the output signal of the low-pass filter 12 from the output signal of the low-pass filter 9 by using the adder 10 to obtain the S as shown by the dotted line in FIG. Curve ε
In addition to generating p, the binarization circuit 14 is used to binarize the output signal of the low-pass filter 6 to generate a state value of +1 or -1, and the multiplier 13 outputs S as shown by the solid line in FIG. A curve εa is generated. DLL3 has an S curve εa
Is set as a control voltage by the loop filter 15, and the reference clock frequency of the VCO 16 is controlled in proportion to the voltage value. Here, the S-curve εa does not reverse the slope in the vicinity of its origin and has a large slope unlike the S-curve in the conventional DLL as shown in FIG.
16 can precisely synchronize the phase of the Manchester code P0 and the phase of the Manchester code on the transmission side, and can control the oscillation clock so as to maintain the synchronization state. The original data can be demodulated normally.
【００１１】更に、送信側及び受信側では直流近傍の周
波数成分が少ないマンチェスタ符号を使用しているか
ら、送受信間を結ぶ伝送路の直流近傍の周波数特性が劣
悪な場合、又はその伝送路に対しスペクトル拡散通信と
直流信号伝送との兼用を希望する場合であっても、これ
等の条件に左右されることなく同期追従を正常に行うこ
とができる。Further, since the transmitting side and the receiving side use the Manchester code, which has few frequency components near DC, when the frequency characteristic near DC of the transmission line connecting the transmission and reception is poor, or for that transmission line. Even when the spread spectrum communication and the DC signal transmission are desired to be combined, the synchronization follow-up can be normally performed without being influenced by these conditions.
【００１２】尚、上述の実施例では逆拡散用マンチェス
タ符号Ｐ０よりも０．５チップ分位相が進んだマンチェ
スタ符号ＰＥ及び符号Ｐ０よりも０．５チップ分位相が
遅れたマンチェスタ符号ＰＬを使用したＤＬＬを説明し
たが、本発明はこれに限らず逆拡散用マンチェスタ符号
Ｐ０よりも所定量位相が進んだマンチェスタ符号及び符
号Ｐ０よりも所定量位相が遅れたマンチェスタ符号ＰＬ
を使用したＤＬＬであっても良く、上述の実施例と同様
の効果が得られることは自明であろう。In the above embodiment, the Manchester code PE which is 0.5 chips ahead of the despreading Manchester code P0 and the Manchester code PL which is 0.5 chips behind the code P0 are used. Although the DLL has been described, the present invention is not limited to this, and the Manchester code PL having a predetermined phase advance from the despreading Manchester code P0 and the Manchester code PL having a predetermined phase delay from the code P0.
It is obvious that a DLL using the above may be used, and the same effect as that of the above-described embodiment can be obtained.
【００１３】又、上述の実施例では２値化回路１４を使
用してローパスフィルタ６の出力信号を２値化して＋１
又は−１の状態値を生成し、乗算器１３の他方の入力端
に供給したが、本発明はこれに替えて例えば状態値が１
及び０のデータを夫々状態値＋１及び−１に変換する手
段をデータ復調器７と前記乗算器１３の他方の入力端と
の間に接続しても良く、上述した実施例と同様の効果が
得られる。In the above embodiment, the binarizing circuit 14 is used to binarize the output signal of the low-pass filter 6 to +1.
Alternatively, a state value of -1 was generated and supplied to the other input terminal of the multiplier 13. However, the present invention replaces this with, for example, a state value of 1
Means for converting the data of 0 and 0 to the state values +1 and -1, respectively, may be connected between the data demodulator 7 and the other input terminal of the multiplier 13, and the same effect as the above-mentioned embodiment can be obtained. can get.
【００１４】[0014]
【発明の効果】本発明は以上説明したように、逆拡散用
マンチェスタ符号よりも位相が進んだマンチェスタ符号
及び位相が遅れたマンチェスタ符号各々でスペクトル拡
散信号を逆拡散した両信号の相互の差分から求めたＳカ
ーブと、前記逆拡散用マンチェスタ符号でスペクトル拡
散信号を逆拡散した信号を２値化して求めた＋１又は−
１の状態信号とを乗積した信号レベルに比例して拡散用
マンチェスタ符号の位相を制御したので、送受信間を結
ぶ伝送路の直流近傍の周波数特性が劣悪な場合、又はそ
の伝送路に対しスペクトル拡散通信と直流信号伝送との
兼用を希望する場合であっても、Ｓカーブの性能を悪化
させることなく送信側と受信側とのマンチェスタ符号の
同期及び同期保持を正確に行うことが可能なＤＬＬを提
供する上で効果がある。As described above, according to the present invention, the spread spectrum signal is despread with the Manchester code whose phase is advanced and the Manchester code whose phase is delayed from the despreading Manchester code. +1 or − obtained by binarizing the obtained S curve and the signal obtained by despreading the spread spectrum signal by the Manchester code for despreading.
Since the phase of the Manchester code for spreading is controlled in proportion to the signal level obtained by multiplying the status signal by 1, the frequency characteristic near the direct current of the transmission line connecting the transmitter and the receiver is poor, or the spectrum for that transmission line is poor. Even if it is desired to use both spread communication and DC signal transmission, a DLL capable of accurately synchronizing and maintaining synchronization of Manchester codes on the transmitting side and the receiving side without deteriorating the performance of the S curve. Is effective in providing.
【図１】本発明の一実施例を示す構成図である。FIG. 1 is a configuration diagram showing an embodiment of the present invention.
【図２】Ｍ系列の自己相関特性図である。FIG. 2 is an autocorrelation characteristic diagram of M series.
【図３】従来のＤＬＬを説明するためのスペクトル拡散
受信機の構成図である。FIG. 3 is a configuration diagram of a spread spectrum receiver for explaining a conventional DLL.
【図４】Ｍ系列を使用した従来のＤＬＬに於けるＳカー
ブを示す図である。FIG. 4 is a diagram showing an S curve in a conventional DLL using an M sequence.
【図５】Ｍ系列及びマンチェスタ符号の周波数スペクト
ルを示す図である。FIG. 5 is a diagram showing frequency spectra of M-sequence and Manchester code.
【図６】マンチェスタ符号の構成を説明するための図で
ある。FIG. 6 is a diagram for explaining the configuration of Manchester code.
【図７】（ａ）はマンチェスタ符号の自己相関特性を、
（ｂ）はマンチェスタ符号を使用した従来のＤＬＬに於
けるＳカーブを示す図である。FIG. 7A shows the autocorrelation characteristic of Manchester code,
(B) is a diagram showing an S curve in a conventional DLL using Manchester code.
【図８】本発明の一実施例に於けるＳカーブを説明する
ための図である。FIG. 8 is a diagram for explaining an S curve in one embodiment of the present invention.
１ スペクトル拡散受信機、２ 拡散符号発生器、３
ＤＬＬ、４ 増幅器、５、８、１１ 乗算器、６、９、
１２及び１３ ローパスフィルタ、７ データ復調器、
１０ 加算器、１４ ２値化回路、１５ ループフィル
タ、１６ 電圧制御発振回路。1 spread spectrum receiver, 2 spread code generator, 3
DLL, 4 amplifiers, 5, 8, 11 multipliers, 6, 9,
12 and 13 low pass filter, 7 data demodulator,
10 adder, 14 binarization circuit, 15 loop filter, 16 voltage controlled oscillator circuit.
Claims (1)
同一チップ分進んだマンチェスタ符号及び遅れたマンチ
ェスタ符号夫々で逆拡散した信号夫々の差分信号レベル
に比例して前記逆拡散用マンチェスタ符号の位相を制御
し、その位相を送信側のマンチェスタ符号の位相に同期
させる手段に於いて、前記逆拡散用マンチェスタ符号で
逆拡散した信号を２値化して求めた＋１又は−１の状態
信号を前記差分信号に掛け合わせて求めた信号レベルに
比例して逆拡散用マンチェスタ符号の位相を制御したこ
とを特徴とする同期追従回路。1. The phase of the despreading Manchester code is proportional to the differential signal level of each of the signals despread by the Manchester code whose phase is advanced by the same chip as the despreading Manchester code and the delayed Manchester code. In the means for controlling and synchronizing the phase with the phase of the Manchester code on the transmission side, the state signal of +1 or -1 obtained by binarizing the signal despread by the Manchester code for despreading is the difference signal. A synchronous tracking circuit characterized in that the phase of the Manchester code for despreading is controlled in proportion to the signal level obtained by multiplying by.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4206037A JPH0629948A (en) | 1992-07-09 | 1992-07-09 | Synchronization tracking circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4206037A JPH0629948A (en) | 1992-07-09 | 1992-07-09 | Synchronization tracking circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0629948A true JPH0629948A (en) | 1994-02-04 |
Family
ID=16516857
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4206037A Pending JPH0629948A (en) | 1992-07-09 | 1992-07-09 | Synchronization tracking circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0629948A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6208683B1 (en) | 1997-06-10 | 2001-03-27 | Nec Corporation | Receiving apparatus for use in CDMA type mobile radio communication system comprising a plurality of path receivers each including a follow-up path detection unit |
| KR100307007B1 (en) * | 1998-09-08 | 2001-11-07 | 가네꼬 히사시 | Mobile communication device having a good tracking precision and a wide following range of synchronization |
| WO2004070981A1 (en) * | 2003-02-05 | 2004-08-19 | Nippon Telegraph And Telephone Corporation | Wireless communication system, wireless transmitter, wireless receiver, wireless communication method, wireless transmission method and wireless reception method |
-
1992
- 1992-07-09 JP JP4206037A patent/JPH0629948A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6208683B1 (en) | 1997-06-10 | 2001-03-27 | Nec Corporation | Receiving apparatus for use in CDMA type mobile radio communication system comprising a plurality of path receivers each including a follow-up path detection unit |
| KR100307007B1 (en) * | 1998-09-08 | 2001-11-07 | 가네꼬 히사시 | Mobile communication device having a good tracking precision and a wide following range of synchronization |
| WO2004070981A1 (en) * | 2003-02-05 | 2004-08-19 | Nippon Telegraph And Telephone Corporation | Wireless communication system, wireless transmitter, wireless receiver, wireless communication method, wireless transmission method and wireless reception method |
| US7545845B2 (en) | 2003-02-05 | 2009-06-09 | Nippon Telegraph And Telephone Corporation | Wireless communication system, wireless transmitter, wireless receiver, wireless communication method, wireless transmission method and wireless reception method |
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