JPH10303996A - Method and device for frequency shift detection - Google Patents
Method and device for frequency shift detectionInfo
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- JPH10303996A JPH10303996A JP11220497A JP11220497A JPH10303996A JP H10303996 A JPH10303996 A JP H10303996A JP 11220497 A JP11220497 A JP 11220497A JP 11220497 A JP11220497 A JP 11220497A JP H10303996 A JPH10303996 A JP H10303996A
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- Prior art keywords
- signal
- phase
- detection
- quadrature
- frequency shift
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Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、位相変調(PS
K)の自動周波数制御(AFC)に関するもので、入力
信号が周波数のずれの有無を判断するための方法及びそ
の装置に関するものである。TECHNICAL FIELD The present invention relates to a phase modulation (PS)
The present invention relates to automatic frequency control (AFC) of K), and to a method and an apparatus for determining whether or not an input signal has a frequency shift.
【0002】[0002]
【従来の技術】近年、映像の映像のディジタル化が進
み、衛星、CATV、地上波のそれぞれの放送メディア
においてディジタル放送が各国で行われようとしてい
る。その伝送方式として、衛星放送では、その伝送路の
非直線性により位相変調が主に用いられる。特に4相位
相変調(QPSK)は、欧州のDigital Video Broadc
asting(DVB−S)をはじめ、アメリカ、更には日本
でも通信衛星を利用したCSディジタル放送で用いられ
ている変調方式である。また、今後伝送容量の増大の要
求から、8PSK、16PSKといった多値化が進むも
のと考えられる。2. Description of the Related Art In recent years, digitalization of video has progressed, and digital broadcasting is being carried out in various countries on satellite, CATV, and terrestrial broadcast media. As a transmission method, phase modulation is mainly used in satellite broadcasting due to the non-linearity of the transmission path. In particular, four-phase phase modulation (QPSK) has been adopted by Digital Video Broadc
This is a modulation method used in CS digital broadcasting using communication satellites in the United States and in Japan as well as asting (DVB-S). In addition, it is considered that multi-valued transmission such as 8PSK and 16PSK will proceed in accordance with a demand for an increase in transmission capacity.
【0003】さてQPSK復調に関しては民生レベルで
は実用化されており、数々の文献でも紹介されている。
その中で復調システムの例として、「多賀、石川、小
松,:“QPSK復調システムの一検討”」(テレビジ
ョン学会技術報告,vol.15,No.46,CE’
91−42(1991.08))に記載された内容につ
いて、簡単に説明する。[0003] QPSK demodulation has been put to practical use at the consumer level, and has been introduced in various documents.
Among them, examples of demodulation systems include “Taga, Ishikawa, and Komatsu:“ A study of QPSK demodulation system ”” (Technical Report of the Institute of Television Engineers of Japan, vol. 15, No. 46, CE ').
91-42 (1991.08)) will be briefly described.
【0004】図12は、QPSK復調システムの構成を
示す図である。図12において、10はQPSK変調信
号入力端子、11は固定周波数の局部発振信号で準同期
直交検波を行って、同相成分(I)、直交成分(Q)の
等化低域信号を得る準同期直交検波手段、12a,12
bはI,Qそれぞれの等価低域信号をAD変換する際に
折り返し成分を除去するためのローパスフィルタ、13
a,13bはI,Qそれぞれの等価低域信号をA/D変
換するA/D変換器,14は自動周波数制御に用いられ
る複素乗算器、15a,15bはQPSK変調波のスペ
クトル整形のためのロールオフフィルタ、16は搬送波
再生のための複素乗算器、17はデータ判定回路、18
a,18bはI,Qデータ出力端子である。FIG. 12 is a diagram showing a configuration of a QPSK demodulation system. In FIG. 12, reference numeral 10 denotes a QPSK modulation signal input terminal, and reference numeral 11 denotes a quasi-synchronous signal for performing quasi-synchronous quadrature detection with a local oscillation signal having a fixed frequency to obtain an equalized low-frequency signal of an in-phase component (I) and a quadrature component (Q). Orthogonal detection means, 12a, 12
b is a low-pass filter for removing aliasing components when AD-converting the I and Q equivalent low-pass signals;
Reference numerals a and 13b denote A / D converters for A / D-converting the equivalent low-frequency signals of I and Q, 14 a complex multiplier used for automatic frequency control, and 15a and 15b for spectrum shaping of QPSK modulated waves. Roll-off filter, 16 is a complex multiplier for carrier recovery, 17 is a data decision circuit, 18
a and 18b are I and Q data output terminals.
【0005】上記の様に構成されたQPSK復調システ
ムについて、主に自動周波数制御(AFC)動作につい
て説明する。The automatic frequency control (AFC) operation of the QPSK demodulation system configured as described above will be mainly described.
【0006】入力端子10より入力された、QPSK変
調信号は準同期直交検波手段11に入力される。準同期
直交検波手段11では、固定発振器50でQPSK変調
波の中心周波数と同じ周波数で発振した局部発振信号及
びその発振信号を90゜移相した信号をそれぞれ混合器
11a及び混合器11bに供給し、QPSK変調波と混
合することにより、QPSK変調波の同相成分(I)、
直交成分(Q)の等価低域信号が得られる。[0006] The QPSK modulated signal input from the input terminal 10 is input to the quasi-synchronous quadrature detection means 11. In the quasi-synchronous quadrature detection means 11, a local oscillation signal oscillated by the fixed oscillator 50 at the same frequency as the center frequency of the QPSK modulation wave and a signal obtained by shifting the oscillation signal by 90 ° are supplied to the mixers 11a and 11b, respectively. , QPSK modulated wave, the in-phase component (I) of the QPSK modulated wave,
An equivalent low-frequency signal of the quadrature component (Q) is obtained.
【0007】このI,Qの等価低域信号は、折り返し除
去フィルタ12a,12bを通った後、A/D変換機1
3a,13bで変調シンボルの中心タイミングでA/D
変換される。ディジタル化された、等価低域信号はそれ
ぞれ複素数の実部及び虚部と見なされる。A/D変換器
13a,13bの出力は、複素乗算器14に入力され、
衛星アンテナにおける周波数変換器(図示せず)等の周
波数ずれに起因する、入力端子10に入力されたQPS
K変調信号と固定発振器50との周波数ずれを補正す
る。After the I and Q equivalent low-pass signals pass through the aliasing filters 12a and 12b, the A / D converter 1
A / D at the center timing of the modulation symbol in 3a and 13b
Is converted. The digitized equivalent low-pass signal is considered the real and imaginary part of the complex number, respectively. Outputs of the A / D converters 13a and 13b are input to a complex multiplier 14,
QPS input to input terminal 10 due to a frequency shift of a frequency converter (not shown) or the like in the satellite antenna
The frequency deviation between the K modulation signal and the fixed oscillator 50 is corrected.
【0008】複素乗算器14の出力はQPSK変調波の
スペクトル整形の為のロ−ルオフフィルタ15a,15
bに入力された後、複素乗算器16に入力され搬送波再
生され、位相の回転が補正される。複素乗算器16の出
力はデータ判定回路17を経て、18a,18bより
I,Qの復調データとして出力される。[0008] The output of the complex multiplier 14 is a roll-off filter 15a, 15 for shaping the spectrum of the QPSK modulated wave.
After being input to b, it is input to the complex multiplier 16 where the carrier is reproduced, and the phase rotation is corrected. The output of the complex multiplier 16 passes through the data determination circuit 17 and is output as I and Q demodulated data from 18a and 18b.
【0009】さて、本システムの自動周波数制御(AF
C)は、直交座標より位相角を求めるarctan手段
20、周波数誤差検出器21、AFCループフィルタ4
1、数値制御発振器42、sin変換回路43、cos
変換回路44で構成されており、周波数誤差検出器21
ではarctan手段20の出力から、1シンボル期間
における位相変化を求めて、これを周波数誤差とするも
のである。周波数誤差は、Now, the automatic frequency control (AF
C) is an arctan means 20 for obtaining a phase angle from rectangular coordinates, a frequency error detector 21, an AFC loop filter 4
1. Numerically controlled oscillator 42, sin conversion circuit 43, cos
The frequency error detector 21 includes a conversion circuit 44.
Then, a phase change in one symbol period is obtained from the output of the arctan means 20, and this is used as a frequency error. The frequency error is
【0010】[0010]
【数1】 (Equation 1)
【0011】で、求められる。QPSKの位相状態は、
図13(a)に示すように、45°、135°、−45
°、−135°といったように90°おきに存在するた
め、1シンボル期間の位相変化(θn−θn-1)は0°か
ら90°までしか表すことができない。従って、周波数
誤差検出器21では1シンボル期間の位相変化(θn−
θn-1)をmod90°により演算し、その位相変化が0
<(θn−θn-1)<45°の時は位相進みとみなして
(θn−θn-1)を周波数誤差とし、45°<(θn−θ
n-1)<90°の時は位相遅れとみなして((θn−
θn-1)−90°)を周波数誤差として、出力する。周波
数誤差検出器の出力はAFCループフィルタ41を介し
て、数値演算発振器42に入力され周波数誤差に応じた
sin波、cos波が生成され、複素乗算器14aで周
波数誤差が補正される。[0011] Then, it is required. The phase state of QPSK is
As shown in FIG. 13A, 45 °, 135 °, −45 °
Since it exists every 90 °, such as ° and -135 °, the phase change (θ n −θ n-1 ) in one symbol period can be expressed only from 0 ° to 90 °. Therefore, the frequency error detector 21 changes the phase (θ n −
θ n-1 ) is calculated by mod 90 °, and the phase change is 0
When <(θ n −θ n−1 ) <45 °, it is regarded as a phase advance and (θ n −θ n−1 ) is set as a frequency error, and 45 ° <(θ n −θ
n-1 ) <90 °, it is regarded as a phase delay ((θ n −
θ n-1 ) -90 °) is output as a frequency error. The output of the frequency error detector is input to a numerical operation oscillator 42 via an AFC loop filter 41, where a sine wave and a cosine wave corresponding to the frequency error are generated, and the frequency error is corrected by the complex multiplier 14a.
【0012】このように、直交座標より位相角を求める
arctan手段20を用いて周波数誤差の検出をする
ことは8相位相変調(8PSK)にも応用することが出
来る。 8PSKの位相状態は図13(b)に示すよう
に、0°、45°、90°、135°、180°,−4
5°、−90°、−135°といったように45°おき
に存在するため、1シンボル期間の位相変化(θn−θ
n-1)は0°から45°までしか表すことができない。従
って、周波数誤差検出器21では1シンボル期間の位相
変化(θn−θn-1)をmod45°により演算し、その
位相変化が0<(θn−θn-1)<22.5°の時は位相
進みとみなして(θn−θn-1)を周波数誤差とし、2
2.5°<(θn−θn-1)<45°の時は位相遅れとみ
なして((θn−θn-1)−45°)を周波数誤差とし
て、出力すればよい。As described above, the detection of the frequency error using the arctan means 20 for obtaining the phase angle from the rectangular coordinates can be applied to eight-phase phase modulation (8PSK). The phase state of 8PSK is 0 °, 45 °, 90 °, 135 °, 180 °, −4 as shown in FIG.
Since it exists every 45 ° such as 5 °, −90 °, and −135 °, the phase change in one symbol period (θ n −θ
n-1 ) can only be expressed from 0 ° to 45 °. Therefore, the frequency error detector 21 calculates the phase change (θ n −θ n−1 ) for one symbol period by mod 45 °, and the phase change is 0 <(θ n −θ n−1 ) <22.5 °. In the case of, the phase error is regarded as (θ n −θ n-1 ), and
When 2.5 ° <(θ n −θ n−1 ) <45 °, the phase delay is regarded as ((θ n −θ n−1 ) −45 °) and the frequency error may be output.
【0013】しかしながら、このような直交座標から極
座標への変換は複雑で回路規模が大きくなってしまうと
いう課題があった。However, there is a problem in that the conversion from the rectangular coordinates to the polar coordinates is complicated and the circuit scale becomes large.
【0014】[0014]
【発明が解決しようとする課題】このように上記の従来
例ではAFCの際の周波数ずれの検出では、直交座標か
ら極座標への複雑な変換が必要になり、そのために回路
規模も大きくなるという課題があった。As described above, in the above-described conventional example, the detection of the frequency shift in the AFC requires a complicated conversion from the rectangular coordinates to the polar coordinates, and therefore the circuit scale becomes large. was there.
【0015】また、今後変調の多値化が進み、複数の種
類の位相変調を処理する必要が出てくる。Further, in the future, multi-level modulation will advance, and it will be necessary to process a plurality of types of phase modulation.
【0016】本発明は上記課題を鑑み、簡単な回路構成
で実現できる8PSKにおける周波数ずれ検出方法並び
に、複数の種類の位相変調に対応できる周波数ずれ検出
方法及びその装置を提供することを目的とする。In view of the above problems, an object of the present invention is to provide a method for detecting a frequency shift in 8PSK, which can be realized with a simple circuit configuration, and a method and apparatus for detecting a frequency shift capable of coping with a plurality of types of phase modulation. .
【0017】[0017]
【課題を解決するための手段】このような課題を解決す
るために本願発明は、8相位相変調信号を直交検波して
得られたI、Qの等価低域信号を連続したシンボル間で
遅延検波を施し、その遅延検波信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で示される8つの領域のどの領域にあるのか領域判定を
行い、前記遅延検波信号が、前記8つの領域のうち、 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波信号の同相または直交
成分を周波数ずれ信号とみなすことを特徴とする周波数
ずれ検出方法に関するものであり、またその検出方法を
達成するための装置として、入力した8相位相変調信号
を直交検波する直交検波手段と、前記直交検波手段の出
力であるI、Qの等価低域信号を入力として連続したシ
ンボル間で遅延検波を行う遅延検波手段と、前記遅延検
波手段で得られた遅延検波信号(同相成分(x)、直交
成分(y))を入力として、その位相について、直交座
標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号の
位相が、前記8つの領域のうち直交座標軸を含む領域 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力する選択手段とを備えることを特徴とする周波数ず
れ検出装置に関するものであり、8PSKのAFCにお
ける周波数ずれ検出方法並びに装置が簡単な回路構成、
すなわち極座標に変換せずに周波数ずれを検出すること
ができる。In order to solve such a problem, the present invention provides a method of delaying an I and Q equivalent low band signal obtained by quadrature detection of an eight-phase modulated signal between successive symbols. Detection is performed, and the phase of the delayed detection signal is (nπ / 4) ± (π / 8) (n = 0, 1, 2, 3, 3).
A determination is made as to which of the eight regions represented by (4,5,6,7) is present, and the differential detection signal is obtained by comparing the (nπ / 2) ± (π / 8) Area (n = 0, 1,
The present invention relates to a frequency shift detecting method characterized in that the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal only when the signal is in (2) or (3), and as an apparatus for achieving the detection method. A quadrature detection unit for performing quadrature detection on the input 8-phase phase modulated signal, and a delay detection unit for performing delay detection between consecutive symbols using as input the I and Q equivalent low band signals output from the quadrature detection unit; The delay detection signal (in-phase component (x), quadrature component (y)) obtained by the above-mentioned delay detection means is input, and its phase is y = x · tan (π / 8) y = −x in the quadrature coordinate system. Tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) Area determination means for performing area determination by dividing the area into eight areas, and the area determination means Output of the differential detection signal Phases, the eight regions including the orthogonal coordinate axes of the areas (nπ / 2) ± (π / 8) in the region (n = 0, 1,
Selecting means for outputting the in-phase component (x) or the quadrature component (y) of the differential detection output signal as a frequency shift signal only when the delay detection output signal is in (2, 3). The method and apparatus for detecting a frequency shift in the 8PSK AFC have a simple circuit configuration,
That is, it is possible to detect a frequency shift without converting to polar coordinates.
【0018】[0018]
【発明の実施の形態】本発明の請求項1記載の発明は、
8相位相変調信号を直交検波して得られたI、Qの等価
低域信号を連続したシンボル間で遅延検波を施し、その
遅延検波信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で示される8つの領域のどの領域にあるのか領域判定を
行い、前記遅延検波信号が、前記8つの領域のうち、 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波信号の同相または直交
成分を周波数ずれ信号とみなすことを特徴とする周波数
ずれ検出方法である。BEST MODE FOR CARRYING OUT THE INVENTION
I and Q equivalent low-frequency signals obtained by quadrature detection of an 8-phase phase modulated signal are subjected to delay detection between consecutive symbols, and the phase of the delayed detection signal is (nπ / 4) ± (π / 8). ) (N = 0, 1, 2, 3,
A determination is made as to which of the eight regions represented by (4,5,6,7) is present, and the differential detection signal is obtained by comparing the (nπ / 2) ± (π / 8) Area (n = 0, 1,
A frequency shift detection method characterized in that the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal only when the differential detection signal is in (2, 3).
【0019】本発明の請求項2記載の発明は、入力した
8相位相変調信号を直交検波する直交検波手段と、前記
直交検波手段の出力であるI、Qの等価低域信号を入力
として連続したシンボル間で遅延検波を行う遅延検波手
段と、前記遅延検波手段で得られた遅延検波信号(同相
成分(x)、直交成分(y))を入力として、その位相
について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号の
位相が、前記8つの領域のうち直交座標軸を含む領域 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力する選択手段とを備えることを特徴とする周波数ず
れ検出装置である。According to a second aspect of the present invention, there is provided a quadrature detection means for quadrature detection of an inputted eight-phase modulated signal, and an I and Q equivalent low band signal output from the quadrature detection means as input signals. And a delay detection means for performing delay detection between the detected symbols, and a delay detection signal (in-phase component (x) and quadrature component (y)) obtained by the delay detection means, and the phase thereof is represented by y = Xtan (π / 8) y = -xtan (π / 8) y = xcot (π / 8) y = -xcot (π / 8) An area determining means for performing an area determination, and a phase of the delayed detection signal based on an output of the area determining means, wherein the phase (nπ / 2) ± (π / 8) of a region (nπ / 2) ± (π / 8) including a rectangular coordinate axis among the eight regions = 0,1,
(2) Only when the signal is in (3), a selecting means for outputting the in-phase component (x) or the quadrature component (y) of the differential detection output signal as a frequency shift signal is provided. is there.
【0020】本発明の請求項3記載の発明は、入力した
8相位相変調信号を直交検波する直交検波手段と、直交
検波手段の出力であるI、Qの等価低域信号を入力とし
て連続したシンボル間で遅延検波を行う遅延検波手段
と、前記遅延検波手段で得られた遅延検波信号(同相成
分(x)、直交成分(y))を入力として、その位相に
ついて、直交座標系で、 y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号の
位相が、前記8つの領域のうち直交座標軸を含む領域 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときにのみ、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力し、それ以外の領域にあるときは前に領域判定をし
た周数ずれ信号を保持する選択手段とを備えることを特
徴とする周波数ずれ検出装置である。According to the invention of claim 3 of the present invention, the quadrature detection means for quadrature detection of the input eight-phase modulated signal, and the I and Q equivalent low band signals output from the quadrature detection means are continuously input. A delay detection means for performing delay detection between symbols, and a delay detection signal (in-phase component (x), quadrature component (y)) obtained by the delay detection means as inputs, and the phase thereof is represented by y in a quadrature coordinate system. = X · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) An area determining means for performing area determination, and a phase of the delayed detection signal based on an output of the area determining means, wherein the area (nπ / 2) ± (π / 8) in the area (nπ / 2) ± (π / 8) including the orthogonal coordinate axes among the eight areas = 0,1,
The in-phase component (x) or the quadrature component (y) of the differential detection output signal is output as a frequency shift signal only when the differential detection output signal is in (2, 3). A frequency shift detecting device, comprising: a selector for holding a frequency shift signal.
【0021】本発明の請求項4記載の発明は、8相位相
変調信号を直交検波して得られたI、Qの等価低域信号
を連続したシンボル間で遅延検波を施し、その遅延検波
信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,4,5,6,7) で示される8つの領域のどの領域にあるか領域判定を行
い、前記遅延検波信号が、前記8つの領域のうち、 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号の同相成分(x)と直
交成分(y)との差を周波数ずれ信号とみなすことを特
徴とする周波数ずれ検出方法である。According to a fourth aspect of the present invention, an I and Q equivalent low band signal obtained by quadrature detection of an eight-phase modulated signal is subjected to delay detection between successive symbols, and the delayed detection signal is obtained. For each of the eight regions, the phase is determined as to which of the eight regions represented by (nπ / 4) ± (π / 8) (n = 0,1,2,3,4,5,6,7) When the differential detection signal is in an area (n = 0, 1, 2, 3) within ((π / 4) + (nπ / 2)) ± (π / 8) among the eight areas. Is a frequency shift detection method, wherein a difference between an in-phase component (x) and a quadrature component (y) of the differential detection signal is regarded as a frequency shift signal.
【0022】本発明の請求項5記載の発明は、入力した
8相位相変調信号を直交検波する直交検波手段と、前記
直交検波手段の出力であるI、Qの等価低域信号を入力
として連続したシンボル間で遅延検波を行う遅延検波手
段と、前記遅延検波手段で得られた遅延検波信号(同相
成分(x)、直交成分(y))を入力として、その位相
について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含まな
い領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときにのみ、前記遅延検波信号の同相成分(x)
と直交成分(y)との差を周波数ずれ信号として出力す
る選択手段とを備えることを特徴とする周波数ずれ検出
装置である。According to a fifth aspect of the present invention, there is provided a quadrature detecting means for quadrature detecting an inputted eight-phase modulated signal, and an I and Q equivalent low band signal output from the quadrature detecting means as an input. And a delay detection means for performing delay detection between the detected symbols, and a delay detection signal (in-phase component (x) and quadrature component (y)) obtained by the delay detection means, and the phase thereof is represented by y = X · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) The phase of the differential detection signal is based on an output of the area determination means for performing area determination and an output of the area determination means, and the phase of the eight areas does not include a rectangular coordinate axis ((π / 4) + (nπ / 2)) ± Only when in the region (n = 0,1,2,3) within (π / 8) Phase component of the serial delay detection signal (x)
And a selection unit that outputs a difference between the frequency component and the orthogonal component (y) as a frequency deviation signal.
【0023】本発明の請求項6記載の発明は、入力した
8相位相変調信号を直交検波する直交検波手段と、前記
直交検波手段の出力であるI、Qの等価低域信号を入力
として連続したシンボル間で遅延検波を行う遅延検波手
段と、前記遅延検波手段で得られた遅延検波信号(同相
成分(x)、直交成分(y))を入力として、その位相
について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含まな
い領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときにのみ、前記遅延検波信号の同相成分(x)
と直交成分(y)との差を周波数ずれ信号として出力
し、それ以外の領域のときは前に領域判定を行った周波
数ずれ信号を保持する選択手段とを備えることを特徴と
する周波数ずれ検出装置である。According to a sixth aspect of the present invention, there is provided a quadrature detection means for quadrature detection of an inputted eight-phase modulation signal, and an I and Q equivalent low-frequency signal output from the quadrature detection means as inputs. And a delay detection means for performing delay detection between the detected symbols, and a delay detection signal (in-phase component (x) and quadrature component (y)) obtained by the delay detection means, and the phase thereof is represented by y in a quadrature coordinate system. = Xtan (π / 8) y = -xtan (π / 8) y = xcot (π / 8) y = -xcot (π / 8) The phase of the differential detection signal is based on an output of the area determination means for performing area determination and an output of the area determination means, and the phase of the eight areas does not include a rectangular coordinate axis ((π / 4) + (nπ / 2)) ± Only when in the region (n = 0,1,2,3) within (π / 8) Phase component of the serial delay detection signal (x)
Frequency difference detection means for outputting a difference between the frequency shift signal and the orthogonal component (y) as a frequency shift signal, and for other areas, holding a frequency shift signal for which the area determination has been performed before. Device.
【0024】本発明の請求項7記載の発明は、8相位相
変調信号を直交検波して得られたI、Qの等価低域信号
を連続したシンボル間で遅延検波を施し、その遅延検波
信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で示される8つの領域のどの領域にあるのかを領域判定
を行い、前記8つの領域のうち (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときは、遅延検波信号の同相または直交成分を周
波数ずれ信号とみなし、また前記8つの領域のうち ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号を(π/4)だけ位相
回転させた信号の同相または直交成分を周波数ずれ信号
とみなすことを特徴とする周波数ずれ検出方法である。According to a seventh aspect of the present invention, an I and Q equivalent low band signal obtained by quadrature detection of an eight-phase modulated signal is subjected to delay detection between successive symbols, and the delayed detection signal is obtained. , The phase is (nπ / 4) ± (π / 8) (n = 0, 1, 2, 3,
A region determination is performed to determine which of the eight regions represented by (4, 5, 6, 7) is located, and a region (n = 0) within (nπ / 2) ± (π / 8) of the eight regions , 1,
2,3), the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal, and ((π / 4) + (nπ / 2)) ± (π / 8) When the differential detection signal is in the region (n = 0, 1, 2, 3), the in-phase or quadrature component of the signal obtained by rotating the differential detection signal by (π / 4) is regarded as a frequency shift signal. Frequency deviation detection method.
【0025】本発明の請求項8記載の発明は、入力した
8相位相変調信号を直交検波する直交検波手段と、前記
直交検波手段の出力であるI、Qの等価低域信号を入力
として連続したシンボル間で遅延検波を行う遅延検波手
段と、前記遅延検波手段の出力を入力として遅延検波信
号を(π/4)位相回転を行う位相回転手段と、前記遅
延検波手段で得られた遅延検波信号(同相成分(x)、
直交成分(y))を入力として、その位相について、直
交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含む領
域 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときは、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力し、直交座標軸を含まない領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記位相回転手段で遅延検波信号を(π
/4)だけ位相回転させた信号の同相成分(x)、また
は直交成分(y)を周波数ずれ信号として出力する選択
手段とを備えることを特徴とする周波数ずれ検出装置で
ある。According to an eighth aspect of the present invention, there is provided a quadrature detection means for quadrature detection of an inputted eight-phase modulated signal, and an I and Q equivalent low band signal output from the quadrature detection means as an input. Delay detecting means for performing delay detection between the symbols detected, phase rotating means for performing the (π / 4) phase rotation of the delayed detection signal by using the output of the delay detecting means as input, and delay detecting means obtained by the delay detecting means. Signal (in-phase component (x),
With the quadrature component (y)) as input, the phase is calculated in the orthogonal coordinate system as follows: y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8), a region determination unit that performs region determination by dividing the region into eight regions, and the phase of the differential detection signal is orthogonal from the eight regions based on the output of the region determination unit. Area (n = 0/2, 1) within the area (nπ / 2) ± (π / 8) including the coordinate axes
2,3), the in-phase component (x) or the quadrature component (y) of the differential detection output signal is output as a frequency shift signal, and the region ((π / 4) + (nπ / 2)) ± (π / 8), the range (n = 0, 1, 2, 3) is satisfied.
/ 4), and a selecting means for outputting an in-phase component (x) or a quadrature component (y) of the signal whose phase has been rotated by / 4) as a frequency shift signal.
【0026】本発明の請求項9記載の発明は、8相位相
変調信号を直交検波して得られたI、Qの等価低域信号
を連続したシンボル間で遅延検波を施し、その遅延検波
信号について、 (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) の8つの領域で領域判定を行い、前記8つの領域のうち ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号の同相成分と直交成分
との差を周波数ずれ信号とみなし、 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときは、前記遅延検波信号を(π/4)だけ位相
回転させた信号の同相成分と直交成分との差を周波数ず
れ信号とみなすことを特徴とする周波数ずれ検出方法で
ある。According to a ninth aspect of the present invention, an I and Q equivalent low band signal obtained by quadrature detection of an eight-phase modulated signal is subjected to delay detection between consecutive symbols, and the delay detection signal is obtained. For (nπ / 4) ± (π / 8) (n = 0,1,2,3,
Region determination is performed on eight regions of (4, 5, 6, 7), and a region (n = 0) within ((π / 4) + (nπ / 2)) ± (π / 8) among the eight regions , 1, 2, 3), the difference between the in-phase component and the quadrature component of the differential detection signal is regarded as a frequency shift signal, and the region (n = 0) within (nπ / 2) ± (π / 8) , 1,
2,3), the difference between the in-phase component and the quadrature component of the signal obtained by rotating the differential detection signal by (π / 4) is regarded as a frequency shift signal. is there.
【0027】本発明の請求項10記載の発明は、入力し
た8相位相変調信号を直交検波する直交検波手段と、前
記直交検波手段の出力であるI、Qの等価低域信号を入
力として連続したシンボル間で遅延検波を行う遅延検波
手段と、前記遅延検波手段の出力を入力として前記遅延
検波信号を(π/4)位相回転を行う位相回転手段と、
前記遅延検波手段で得られた遅延検波信号(同相成分
(x)、直交成分(y))を入力として、その位相につ
いて、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号
が、8つの領域のうち直交座標軸を含まない領域 ((π/4+nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは遅延検波信号の同相成分(x)と直交成分
(y)との差を周波数ずれ信号として出力し、直交座標
軸を含む領域( nπ/2±π/8内の領域:n=0,
1,2,3)にあるときは、前記位相回転手段で前記遅
延検波信号(π/4)だけ位相回転させた信号の同相成
分(x)と直交成分(y)との差を周波数ずれ信号とし
て出力する選択手段とを備えることを特徴とする周波数
ずれ検出装置である。According to a tenth aspect of the present invention, there is provided a quadrature detection means for quadrature detection of an inputted eight-phase modulated signal, and an I and Q equivalent low-pass signal output from the quadrature detection means as inputs. Delay detection means for performing delay detection between the selected symbols, phase rotation means for performing (π / 4) phase rotation of the differential detection signal by using an output of the delay detection means as an input,
The delay detection signal (in-phase component (x), quadrature component (y)) obtained by the above-mentioned delay detection means is input, and its phase is y = x · tan (π / 8) y = −x in the quadrature coordinate system. Tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) Area determination means for performing area determination by dividing the area into eight areas, and the area determination means From the output of the above, the delayed detection signal is a region within the region ((π / 4 + nπ / 2)) ± (π / 8) which does not include the orthogonal coordinate axis among the eight regions.
When (n = 0, 1, 2, 3), the difference between the in-phase component (x) and the quadrature component (y) of the differential detection signal is output as a frequency shift signal, and the region including the quadrature coordinate axis (nπ / 2 Area within ± π / 8: n = 0,
1, 2, 3), the difference between the in-phase component (x) and the quadrature component (y) of the signal rotated in phase by the delayed detection signal (π / 4) by the phase rotation means is used as a frequency shift signal. And a selecting means for outputting the frequency deviation.
【0028】本発明の請求項11記載の発明は、遅延検
波信号の直交座標系の領域判定について、領域判定直線
を位相変調の種類によって切り替えるとともに、その領
域判定により、遅延検波出力が直交座標の座標軸を含む
領域にあるときは、遅延検波信号の同相または直交成分
を周波数ずれ信号とみなすことを特徴とする周波数ずれ
検出方法である。According to an eleventh aspect of the present invention, in the area determination of the differential detection signal in the orthogonal coordinate system, the area determination straight line is switched according to the type of phase modulation, and the differential detection output is determined by the area determination. A frequency shift detection method is characterized in that when in an area including a coordinate axis, an in-phase or quadrature component of a differential detection signal is regarded as a frequency shift signal.
【0029】発明の請求項12記載の発明は、遅延検波
信号の直交座標系の領域判定手段に、位相変調の種類に
応じて判定領域の切り替えを行う判定領域切り替え手段
を備え領域判定手段の出力により、遅延検波信号が直交
座標の座標軸を含む領域にあるときのみ、遅延検波信号
の同相成分(x)、または直交成分(y)を周波数ずれ
信号として出力する選択手段、とを備えることを特徴と
する周波数ずれ検出装置である。According to a twelfth aspect of the present invention, the area detection means of the quadrature coordinate system of the differential detection signal includes a determination area switching means for switching the determination area according to the type of phase modulation. Selection means for outputting the in-phase component (x) or the quadrature component (y) of the differential detection signal as a frequency shift signal only when the differential detection signal is in a region including the coordinate axes of the rectangular coordinates. Is a frequency shift detecting device.
【0030】以下、本発明の実施の形態について、図1
から図4を用いて説明する。 (実施の形態1)図1は本発明の第1の実施の形態の周
波数ずれ検出装置の構成図を示したものであり、1a,
1bは8PSK信号を直交検波して得られた同相成分
(I)、直交成分(Q)の等価低域信号入力端子、2は
1シンボル遅延手段、3は複素共役生成手段、4は複素
乗算手段、5は領域判定手段、6a,6bは符号反転手
段、7は選択手段、8は周波数ずれ信号出力端子であ
る。以下にその動作を説明する。Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 shows a configuration diagram of a frequency shift detecting apparatus according to a first embodiment of the present invention.
1b is an equivalent low-band signal input terminal for an in-phase component (I) and a quadrature component (Q) obtained by quadrature detection of an 8PSK signal, 2 is a 1-symbol delay unit, 3 is a complex conjugate generation unit, 4 is a complex multiplication unit Numeral 5 is a region determining means, 6a and 6b are sign inverting means, 7 is a selecting means, and 8 is a frequency shift signal output terminal. The operation will be described below.
【0031】8PSK信号を直交検波して得られた同相
成分(I)、直交成分(Q)の等価低域信号は1a,1
bの入力端子に入力される。このI,Qの等価低域信号
はディジタル化されており、等価低域信号はそれぞれ複
素数の実部及び虚部と見なされる。この等価低域信号は
衛星アンテナにおける周波数変換器(図示せず)等に起
因する周波数ずれを含んでいる。The equivalent low-frequency signals of the in-phase component (I) and the quadrature component (Q) obtained by quadrature detection of the 8PSK signal are 1a, 1
is input to the input terminal b. The I and Q equivalent low band signals are digitized, and the equivalent low band signals are regarded as a real part and an imaginary part of a complex number, respectively. This equivalent low-frequency signal includes a frequency shift caused by a frequency converter (not shown) in the satellite antenna or the like.
【0032】周波数ずれを含んだI,Qの等価低域信号
は、1シンボル期間での遅延検波が行われる。遅延検波
は1シンボル遅延手段2と、複素共役生成手段3と、複
素乗算手段4とによって構成され、現在の等価低域信号
と、1シンボル前の等価低域信号の複素共役信号とが複
素乗算される。これを式で表すとThe I and Q equivalent low-frequency signals including the frequency shift are subjected to delay detection in one symbol period. The differential detection is constituted by one-symbol delay means 2, complex conjugate generation means 3, and complex multiplication means 4, and performs complex multiplication of the current equivalent low band signal and the complex conjugate signal of the equivalent low band signal one symbol before. Is done. This can be expressed as
【0033】[0033]
【数2】 (Equation 2)
【0034】のようになる。この(数2)より、等価低
域信号に周波数ずれが無ければ遅延検波出力の位相状態
は、図12の位相状態図の●によって示すように、π/
4・n(n=0〜7)の8点にある。しかし、周波数ず
れ(Δf)があると、位相が2π・Δf・Ts分、●の
位置よりずれることになる。Is as follows. From this (Equation 2), if there is no frequency shift in the equivalent low-frequency signal, the phase state of the differential detection output becomes π / π as shown by ● in the phase state diagram of FIG.
There are eight points of 4 · n (n = 0 to 7). However, if there is a frequency shift (Δf), the phase shifts by 2π · Δf · Ts from the position of ●.
【0035】さてこの遅延検波出力より周波数ずれを求
めるのに、直交座標から極座標に変換することなく行う
ために、直交座標上で周波数ずれとほぼ比例する値を選
ぶ必要がある。そこで、図2(a)に示すように遅延検
波出力結果を nπ/4±π/8 (n=0,1,2,3,4,5,
6,7) で8つの領域に分け、そのうち座標軸を含む領域 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3)) すなわち領域a,領域b,領域c,領域dの各領域に、
遅延検波出力の位相が入ったときに、遅延検波出力の同
相成分(x)と、直交成分(y)が周波数ずれに比例す
る値とみなすことが出来る。Now, in order to obtain a frequency shift from the delayed detection output without converting the rectangular coordinates into polar coordinates, it is necessary to select a value substantially proportional to the frequency shift on the rectangular coordinates. Therefore, as shown in FIG. 2A, the delay detection output result is expressed as nπ / 4 ± π / 8 (n = 0, 1, 2, 3, 4, 5,
6,7) to divide into eight areas, of which the area (nπ / 2) ± (π / 8) including the coordinate axes (n = 0,1,
2, 3)) That is, in each of the area a, the area b, the area c, and the area d,
When the phase of the differential detection output enters, the in-phase component (x) and the quadrature component (y) of the differential detection output can be regarded as values proportional to the frequency shift.
【0036】例えば、a領域((0)±(π/8)内の
領域)について考えると、0を境に(+π/8)までが
周波数が進んでおり、遅延検波出力の直交成分(y)は
正になり、周波数の進みが大きくなるとともにその値も
大きくなる。一方、0を境に(−π/8)までが周波数
が遅れており、遅延検波出力の直交成分(y)は負にな
り、周波数の遅れが大きくなると共にその値も小さくな
る。For example, considering the region a (region within (0) ± (π / 8)), the frequency is advanced from (0) to (+ π / 8), and the quadrature component (y ) Becomes positive, and the value increases as the frequency advance increases. On the other hand, the frequency is delayed from (0) to (−π / 8), the quadrature component (y) of the differential detection output becomes negative, and the value of the frequency delay increases and the value decreases.
【0037】このように図2のa,b,c,d領域の
時、その周波数ずれに比例する値として、図2(b)に
示すように、それぞれy(直交成分),−x(同相成
分),−y(直交成分),x(同相成分)を周波数ずれ
信号として出力し、それ以外のときは出力しないように
することが本発明の特徴である。As shown in FIG. 2B, in the case of the regions a, b, c, and d in FIG. 2, y (quadrature component) and −x (in-phase It is a feature of the present invention to output the component, −y (quadrature component), and x (in-phase component) as frequency shift signals, and not output them at other times.
【0038】そのために、遅延検波出力は領域判定手段
5に入力され、図2(a),図2(b)に示すように、
直交座標系でy=x・tan(π/8)、 y=−x・
tan(π/8)、y=x・cot(π/8)、及びy
=―x・cot(π/8)の直線により区切られた領域
に、その遅延検波信号の位相が、どこに含まれるのかを
検知し、すなわち8つの領域での領域判定を行う。選択
手段7は領域判定手段5の領域判定結果により、遅延検
波信号が8つの領域のうち、y=x・tan(π/8)
とy=−x・tan(π/8)に挟まれた領域a,領域
cのうち、領域aのとき(y<x・tan(π/8)か
つ、y>−x・tan(π/8)のとき)は遅延検波信
号の直交成分(y)を周波数ずれ信号とし、領域cのと
き(y>x・tan(π/8)かつ、y<−x・tan
(π/8)のとき)は遅延検波信号の直交成分(y)・
(−1)を周波数ずれ信号とし、また、y=x・cot
(π/8)とy=―x・cot(π/8)に挟まれた領
域b,領域dのうち、領域bのとき(y>x・cot
(π/8)かつ、y>−x・cot(π/8)のとき)
は遅延検波信号の同相成分(x)・(−1)を周波数ず
れ信号とし、領域dのとき(y<x・cot(π/8)
かつ、y<−x・cot(π/8)のとき)は遅延検波
信号の同相成分(x)を周波数ずれ信号として出力す
る。For this purpose, the differential detection output is input to the area determining means 5, and as shown in FIGS. 2 (a) and 2 (b),
Y = x · tan (π / 8) in a rectangular coordinate system, y = −x ·
tan (π / 8), y = x · cot (π / 8), and y
It detects where the phase of the differential detection signal is included in a region delimited by a straight line of = −x · cot (π / 8), that is, performs region determination in eight regions. The selection means 7 determines y = x · tan (π / 8) of the eight areas of the differential detection signal based on the area determination result of the area determination means 5.
And y = −x · tan (π / 8), the region a and the region c, when the region a (y <x · tan (π / 8) and y> −x · tan (π / 8)), the quadrature component (y) of the differential detection signal is used as the frequency shift signal, and in the region c (y> xtan (π / 8) and y <-xtan)
(When π / 8)) is the orthogonal component (y) ·
(-1) is a frequency shift signal, and y = x · cot
(Π / 8) and y = −x · cot (π / 8), among the regions b and d, when region b (y> x · cot)
(Π / 8) and y> -x · cot (π / 8)
Is the in-phase component (x) · (−1) of the differential detection signal as a frequency shift signal, and in a region d (y <x · cot (π / 8)
When y <−x · cot (π / 8)), the in-phase component (x) of the differential detection signal is output as a frequency shift signal.
【0039】そして、上記領域a,領域b,領域c,領
域d以外の領域のときは、何も出力しないか、もしくは
前の周波数ずれ信号を保持するようにする。In areas other than the areas a, b, c and d, no signal is output or the previous frequency shift signal is held.
【0040】以上により、周波数ずれを求めるのに、直
交座標から極座標に変換する複雑な変換をすることな
く、周波数ずれを検出することが可能になる。As described above, it is possible to detect a frequency shift without performing a complicated conversion from the rectangular coordinates to the polar coordinates in order to obtain the frequency shift.
【0041】これによって得られた周波数ずれ信号は、
図16に示すように、ディジタルAFCとして、ループ
フィルタ41、数値演算発振回路(NCO)42、si
n変換手段43,cos変換手段44、複素乗算器14
を介して周波数制御が可能であるとともに、また図17
に示すように、準同期直交検波の局部発振回路を電圧制
御発振器(VCO)とすることにより、ループフィルタ
41、D/A変換器70、準同期直交検波を介したAF
Cが可能となる。The resulting frequency shift signal is
As shown in FIG. 16, as a digital AFC, a loop filter 41, a numerical operation oscillation circuit (NCO) 42, si
n conversion means 43, cos conversion means 44, complex multiplier 14
The frequency can be controlled through the
As shown in (1), the local oscillation circuit of the quasi-synchronous quadrature detection is a voltage controlled oscillator (VCO), so that the loop filter 41, the D / A converter 70, and the AF through the quasi-synchronous quadrature detection
C becomes possible.
【0042】なお、領域判定手段5における領域判定に
ついて、遅延検波出力の絶対値をとり直交座標の第1象
現(x≧0かつy≧0)において y=x・tan(π
/8)、y=x・cot(π/8)の直線で0からπ/
2までの範囲の領域を判定し、遅延検波出力x、yの符
号を用いて座標の象現を判定することにより、8つの領
域を判定することができることは言うまでもない。In the area judgment by the area judgment means 5, the absolute value of the differential detection output is taken, and in the first quadrant (x ≧ 0 and y ≧ 0) of the orthogonal coordinates, y = x · tan (π
/ 8), y = x · cot (π / 8) on a straight line from 0 to π /
It is needless to say that eight regions can be determined by determining the region of up to 2 and determining the coordinate representation using the signs of the differential detection outputs x and y.
【0043】また、領域判定に用いるtan(π/8)
及びcot(π/8)の値についは、有限値にしても問
題にならないことは言うまでもない。Also, tan (π / 8) used for area determination
It goes without saying that there is no problem even if the values of and cot (π / 8) are finite.
【0044】(実施の形態2)図3は本発明の第2の実
施の形態を示したものであり、1a,1bは8PSK信
号を直交検波して得られた同相成分(I)、直交成分
(Q)の等価低域信号入力端子、2は1シンボル遅延手
段、3は複素共役生成手段、4は複素乗算手段、5は領
域判定手段、106a,106bは絶対値生成手段、1
07は引き算手段、108は符号反転手段、7は選択手
段、8は周波数ずれ信号出力端子である。以下にその動
作を説明する。(Embodiment 2) FIG. 3 shows a second embodiment of the present invention, wherein 1a and 1b denote in-phase components (I) and quadrature components obtained by quadrature detection of an 8PSK signal. (Q) Equivalent low band signal input terminal, 2 is one symbol delay means, 3 is complex conjugate generation means, 4 is complex multiplication means, 5 is area determination means, 106a and 106b are absolute value generation means, 1
07 is a subtraction means, 108 is a sign inversion means, 7 is a selection means, and 8 is a frequency shift signal output terminal. The operation will be described below.
【0045】8PSK信号を直交検波して得られた同相
成分(I)、直交成分(Q)の等価低域信号は1a,1
bの入力端子に入力される。このI,Qの等価低域信号
はディジタル化されており、等価低域信号はそれぞれ複
素数の実部及び虚部と見なされる。この等価低域信号は
衛星アンテナにおける周波数変換器(図示せず)等に起
因する周波数ずれを含んでいる。The equivalent low band signals of the in-phase component (I) and the quadrature component (Q) obtained by quadrature detection of the 8PSK signal are 1a, 1
is input to the input terminal b. The I and Q equivalent low band signals are digitized, and the equivalent low band signals are regarded as a real part and an imaginary part of a complex number, respectively. This equivalent low-frequency signal includes a frequency shift caused by a frequency converter (not shown) in the satellite antenna or the like.
【0046】周波数ずれを含んだI,Qの等価低域信号
は、1シンボル期間での遅延検波が行われる。遅延検波
を構成するのは1シンボル遅延手段2と、複素共役生成
手段3と、複素乗算手段4とで構成され、現在の等価低
域信号と、1シンボル前の等価低域信号の複素共役信号
とが複素乗算される。これを式で表すと(数2)のよう
になる。The I and Q equivalent low-frequency signals including the frequency shift are subjected to differential detection in one symbol period. The delay detection is composed of a one-symbol delay means 2, a complex conjugate generation means 3, and a complex multiplication means 4, and is a complex conjugate signal of the current equivalent low-band signal and the equivalent low-band signal of one symbol before. And are complex multiplied. When this is expressed by an equation, it becomes as shown in (Equation 2).
【0047】この(数2)より、等価低域信号に周波数
ずれが無ければ遅延検波出力の位相状態は図12の位相
状態図の●に示すようにπ/4・n(n=0〜7)にあ
る。しかし、周波数ずれΔfがあると2π・Δf・Ts
の分、位相が●よりずれることになる。From this (Equation 2), if there is no frequency shift in the equivalent low band signal, the phase state of the differential detection output is π / 4 · n (n = 0 to 7) as shown by ● in the phase diagram of FIG. )It is in. However, if there is a frequency shift Δf, 2π · Δf · Ts
, The phase is shifted from ●.
【0048】さて、この遅延検波出力より周波数ずれを
求めるのに、直交座標から極座標に変換することなく行
うために、直交座標上で周波数ずれとほぼ比例する値を
選ぶ必要がある。そこで、図4(a)の位相状態図に示
すように、遅延検波出力結果を (nπ/4)±(π/8)(n=0,1,2,3,4,
5,6,7) で8つの領域に分け、そのうち座標軸を含まない領域、
すなわち (π/4)+(nπ/2)±(π/8) 内の領域(n
=0,1,2,3) 領域e,領域f,領域g,領域hの各領域に入ったとき
に、図4(b)に示すように遅延検波出力の同相成分
(x)と、直交成分(y)との差が周波数ずれとほぼ比
例した信号とみなすことが出来る。Now, in order to obtain the frequency shift from the delayed detection output without converting from the rectangular coordinates to the polar coordinates, it is necessary to select a value substantially proportional to the frequency shift on the rectangular coordinates. Therefore, as shown in the phase diagram of FIG. 4A, the delay detection output result is expressed as (nπ / 4) ± (π / 8) (n = 0, 1, 2, 3, 4, 4).
5,6,7) to divide into 8 areas, of which area does not include coordinate axes,
That is, the region (n) within (π / 4) + (nπ / 2) ± (π / 8)
= 0, 1, 2, 3) When entering each of the regions e, f, g and h, the in-phase component (x) of the differential detection output and the quadrature The difference from the component (y) can be regarded as a signal substantially proportional to the frequency shift.
【0049】例えば、e領域(π/4±π/8内の領
域)であると、π/4を境にπ/4+π/8までが周波
数が進んでおり、遅延検波出力の同相成分(x)と、直
交成分(y)との差(|y|−|x|)は正になり、周
波数の進みが大きくなるとともにその値も大きくなる。
一方、π/4を境にπ/4−π/8までが周波数が遅れ
ており、遅延検波出力の同相成分(x)と、直交成分
(y)との差(|y|−|x|)は負になり、周波数の
遅れが大きくなると共にその値も小さくなる。For example, in the e region (region within π / 4 ± π / 8), the frequency advances from π / 4 to π / 4 + π / 8, and the in-phase component (x ) And the orthogonal component (y) become positive (| y | − | x |), and the value increases as the frequency advance increases.
On the other hand, the frequency is delayed from π / 4 to π / 4−π / 8 at the boundary of π / 4, and the difference (| y | − | x |) between the in-phase component (x) of the differential detection output and the quadrature component (y) is delayed. ) Becomes negative, the value of which becomes smaller as the frequency lag increases.
【0050】このように領域e,領域f,領域g,領域
hの時、その周波数ずれに比例する値として、図4
(c)に示すように、それぞれ (|y|−|x|)、−(|y|−|x|) (|y|−|x|)、−(|y|−|x|) を周波数ずれ信号として出力し、それ以外のときは出力
しないようにするのが本発明の特徴である。。As described above, in the case of the region e, the region f, the region g, and the region h, a value proportional to the frequency shift is shown in FIG.
As shown in (c), (| y |-| x |),-(| y |-| x |), (| y |-| x |) and-(| y |-| x |) It is a feature of the present invention that the signal is output as a frequency shift signal and is not output at other times. .
【0051】そのために、遅延検波出力は領域判定手段
5に入力され、図4(a),図4(c)に示すように、
直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により遅延検波信号を8つの領域で領域判定を行
い、また、遅延検波出力(x),(y)は絶対値生成手
段106a、106b、引き算手段107、及び符号反
転手段108により、 (π/4)+(nπ/2)±(π/8) 内の領域(n
=0,1,2,3) における周波数ずれに比例する値となる (|y|−|x|) 及び、 −(|y|−|x|) を生成する。For this purpose, the differential detection output is input to the area determining means 5, and as shown in FIGS. 4 (a) and 4 (c),
Delayed in a rectangular coordinate system by a straight line of y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) The detection signal is subjected to area determination in eight areas, and the delayed detection outputs (x) and (y) are calculated by the absolute value generation means 106a and 106b, the subtraction means 107, and the sign inversion means 108 by (π / 4) + The region (n) within (nπ / 2) ± (π / 8)
= 0, 1, 2, 3) (| y |-| x |) and-(| y |-| x |), which are values proportional to the frequency shift at (= 0, 1, 2, 3).
【0052】選択手段7は領域判定手段5の領域判定結
果により、遅延検波信号が8つの領域のうちy=x・t
an(π/8)と y=x・cot(π/8)に挟まれ
た領域eのとき、すなわちy>x・tan(π/8)
かつ y<x・cot(π/8) のとき及び、領域g
のとき、すなわちy<x・tan(π/8)かつ、y>
x・cot(π/8)のときは遅延検波信号の(|y|
−|x|)を周波数ずれ信号とし、また、y=−x・t
an(π/8)とy=―x・cot(π/8)に挟まれ
た領域fのとき、すなわちy>−x・tan(π/8)
かつ y<−x・cot(π/8) のとき及び、領
域hのとき、すなわちy<−x・tan(π/8) か
つ y>−x・cot(π/8) のときは遅延検波信
号の−(|y|−|x|)を周波数ずれ信号として出力
する。Based on the area judgment result of the area judgment means 5, the selection means 7 determines that the delayed detection signal is y = x · t out of the eight areas.
In the region e sandwiched between an (π / 8) and y = x · cot (π / 8), ie, y> x · tan (π / 8)
And y <x · cot (π / 8) and the region g
, That is, y <x · tan (π / 8) and y>
When x · cot (π / 8), (| y |
− | X |) as a frequency shift signal, and y = −x · t
When the region f is sandwiched between an (π / 8) and y = −x · cot (π / 8), that is, y> −x · tan (π / 8)
And when y <−x · cot (π / 8) and in the region h, that is, when y <−x · tan (π / 8) and y> −x · cot (π / 8), differential detection is performed. The signal-(| y |-| x |) is output as a frequency shift signal.
【0053】そして、上記領域e,領域f,領域g,領
域h以外の領域のときは、何も出力しないか、もしくは
前の周波数ずれ信号を保持するようにする。In a region other than the regions e, f, g and h, nothing is output or the previous frequency shift signal is held.
【0054】以上の構成により、周波数ずれを求めるの
に、直交座標から極座標に変換する複雑な変換をするこ
となく、周波数ずれを検出することが可能になる。With the above configuration, it is possible to detect a frequency shift without performing a complicated conversion from a rectangular coordinate to a polar coordinate to obtain the frequency shift.
【0055】これによって得られた、周波数ずれ信号は
図16に示すようにディジタルAFCとして、ループフ
ィルタ41、数値演算発振回路(NCO)42、sin
変換手段43,cos変換手段44、複素乗算器を介し
て周波数制御が可能である共に、図15に示すように準
同期直交検波の局部発振回路を電圧制御発振器(VC
O)とすることにより、ループフィルタ、D/A変換
器、準同期直交検波を介したAFCが可能となる。The frequency shift signal obtained in this way is converted into a digital AFC as shown in FIG. 16 as a loop filter 41, a numerical operation oscillator (NCO) 42,
The frequency control is possible via the conversion means 43, the cos conversion means 44, and the complex multiplier, and the local oscillation circuit for quasi-synchronous quadrature detection is connected to a voltage controlled oscillator (VC) as shown in FIG.
By setting O), AFC through a loop filter, a D / A converter, and quasi-synchronous quadrature detection becomes possible.
【0056】なお、領域判定手段5における領域判定に
ついて、遅延検波出力の絶対値をとり直交座標の第1象
現(x≧0かつy≧0)において y=x・tan(π
/8)、y=x・cot(π/8)の直線で0からπ/
2までの範囲の領域を判定し、遅延検波出力x、yの符
号を用いて座標の象現を判定することにより、8つの領
域を判定することができることは言うまでもない。In the area judgment by the area judgment means 5, the absolute value of the delay detection output is taken and y = x · tan (π) in the first quadrant (x ≧ 0 and y ≧ 0) of the orthogonal coordinates.
/ 8), y = x · cot (π / 8) on a straight line from 0 to π /
It is needless to say that eight regions can be determined by determining the region of up to 2 and determining the coordinate representation using the signs of the differential detection outputs x and y.
【0057】また、領域判定に用いるtan(π/8)
及びcot(π/8)の値についは、有限値にしても問
題にならないことは言うまでもない。Also, tan (π / 8) used for area determination
It goes without saying that there is no problem even if the values of and cot (π / 8) are finite.
【0058】(実施の形態3)図5は本発明の第3の実
施の形態を示したものであり、1a,1bは8PSK信
号を直交検波して得られた同相成分(I)、直交成分
(Q)の等価低域信号入力端子、2は1シンボル遅延手
段、3は複素共役生成手段、4は複素乗算手段、5は領
域判定手段、6a,6b,6c,6dは符号反転手段、
7は選択手段、110はπ/4移相手段、8は周波数ず
れ信号出力端子である。以下にその動作を説明する。(Embodiment 3) FIG. 5 shows a third embodiment of the present invention, wherein 1a and 1b show an in-phase component (I) and a quadrature component obtained by quadrature detection of an 8PSK signal. (Q) Equivalent low band signal input terminal, 2 is one symbol delay means, 3 is complex conjugate generation means, 4 is complex multiplication means, 5 is area determination means, 6a, 6b, 6c and 6d are sign inversion means,
7 is a selection means, 110 is a π / 4 phase shift means, and 8 is a frequency shift signal output terminal. The operation will be described below.
【0059】8PSK信号を直交検波して得られた同相
成分(I)、直交成分(Q)の等価低域信号は1a,1
bの入力端子に入力される。このI,Qの等価低域信号
はディジタル化されており、等価低域信号はそれぞれ複
素数の実部及び虚部と見なされる。この等価低域信号は
衛星アンテナにおける周波数変換器(図示せず)等に起
因する周波数ずれを含んでいる。The equivalent low-frequency signals of the in-phase component (I) and the quadrature component (Q) obtained by quadrature detection of the 8PSK signal are 1a, 1
is input to the input terminal b. The I and Q equivalent low band signals are digitized, and the equivalent low band signals are regarded as a real part and an imaginary part of a complex number, respectively. This equivalent low-frequency signal includes a frequency shift caused by a frequency converter (not shown) in the satellite antenna or the like.
【0060】周波数ずれを含んだI,Qの等価低域信号
は、1シンボル期間での遅延検波が行われる。遅延検波
を構成するのは1シンボル遅延手段2と、複素共役生成
手段3と、複素乗算手段4とで構成され、現在の等価低
域信号と、1シンボル前の等価低域信号の複素共役信号
とが複素乗算される。これを式で表すと(数2)のよう
になる。The I and Q equivalent low-frequency signals including the frequency shift are subjected to delay detection in one symbol period. The delay detection is composed of a one-symbol delay means 2, a complex conjugate generation means 3, and a complex multiplication means 4, and is a complex conjugate signal of the current equivalent low-band signal and the equivalent low-band signal of one symbol before. And are complex multiplied. When this is expressed by an equation, it becomes as shown in (Equation 2).
【0061】この(数2)より、等価低域信号に周波数
ずれが無ければ遅延検波出力の位相状態は図12の位相
状態図の●に示すようにπ/4・n(n=0〜7)にあ
る。しかし、周波数ずれΔfがあると2π・Δf・Ts
の分、位相が●よりずれることになる。From this (Equation 2), if there is no frequency shift in the equivalent low band signal, the phase state of the differential detection output is π / 4 · n (n = 0 to 7) as shown by ● in the phase state diagram of FIG. )It is in. However, if there is a frequency shift Δf, 2π · Δf · Ts
, The phase is shifted from ●.
【0062】さてこの遅延検波出力より周波数ずれを求
めるのに、直交座標から極座標に変換することなく行う
ために、直交座標上で周波数ずれとほぼ比例する値を選
ぶ必要がある。そこで、位相状態図の図6(a)に示す
ように、遅延検波出力結果を (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で8つの領域に分け、そのうち座標軸を含む領域、すな
わち (nπ/2)±(π/8) 内の領域(n=0,1,
2,3)) 領域a,領域b,領域c,領域dの各領域に入ったとき
に、遅延検波出力の同相成分(x)または、直交成分
(y)は周波数ずれと比例した信号とみなすことが出来
る。In order to determine the frequency shift from the delayed detection output without converting the rectangular coordinates to the polar coordinates, it is necessary to select a value substantially proportional to the frequency shift on the rectangular coordinates. Therefore, as shown in the phase diagram of FIG. 6A, the delay detection output result is expressed as (nπ / 4) ± (π / 8) (n = 0, 1, 2, 3, 3).
4,5,6,7) to divide into eight regions, of which a region including the coordinate axes, that is, a region (n = 0,1,) within (nπ / 2) ± (π / 8)
2, 3)) When entering each of the regions a, b, c and d, the in-phase component (x) or the quadrature component (y) of the differential detection output is regarded as a signal proportional to the frequency shift. I can do it.
【0063】例えば、a領域(0±π/8内の領域)で
あると、0を境に(+π/8)までが周波数が進んでお
り、遅延検波出力の直交成分(y)は正になり、周波数
の進みが大きくなるとともにその値も大きくなる。一
方、0を境に(−π/8)までが周波数が遅れており、
遅延検波出力の直交成分(y)は負になり、周波数の遅
れが大きくなると共にその値も小さくなる。For example, in the area a (area within 0 ± π / 8), the frequency is advanced from (0) to (+ π / 8), and the quadrature component (y) of the differential detection output is positive. That is, as the advance of the frequency increases, the value also increases. On the other hand, the frequency is delayed from (0) to (−π / 8),
The quadrature component (y) of the differential detection output becomes negative, and as the frequency delay increases, its value also decreases.
【0064】このように領域a,領域b,領域c,領域
dの時、その周波数ずれに比例する値として、図6
(a)に示すように、それぞれy,−x,−y,xを周
波数ずれ信号として出力する。As described above, in the case of the region a, the region b, the region c, and the region d, a value proportional to the frequency shift is shown in FIG.
As shown in (a), y, -x, -y, x are output as frequency shift signals.
【0065】一方、8つの領域の内、座標軸を含まない
領域、すなわち (π/4)+(nπ/2)±(π/8) 内の領域(n
=0,1,2,3) 領域e,領域f,領域g,領域hの各領域にある時、図
6(b)に示すように遅延検波信号をπ/4だけ位相回
転させることにより、その信号の同相成分(x)、直交
成分(y)もまた、周波数ずれと比例した信号とみなす
ことが出来る。On the other hand, of the eight regions, a region not including the coordinate axis, that is, a region (n) within (π / 4) + (nπ / 2) ± (π / 8)
= 0, 1, 2, 3) When the differential detection signal is in each of the regions e, f, g and h, the phase of the differential detection signal is rotated by π / 4 as shown in FIG. The in-phase component (x) and the quadrature component (y) of the signal can also be regarded as signals proportional to the frequency shift.
【0066】そのために、遅延検波出力は領域判定手段
5に入力され、図6(a)に示すように、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により遅延検波信号を8つの領域で領域判定を行
い、また、遅延検波出力(x),(y)は位相回転手段
110により、π/4だけ位相が回転される。For this purpose, the delay detection output is input to the area determining means 5, and as shown in FIG. 6A, y = x · tan (π / 8) y = −x · tan (π) in the rectangular coordinate system. / 8) y = x · cot (π / 8) y = −x · cot (π / 8) The area of the differential detection signal is determined in eight areas, and the differential detection output (x), (x In y), the phase is rotated by π / 4 by the phase rotation means 110.
【0067】π/4の位相回転は、The phase rotation of π / 4 is
【0068】[0068]
【数3】 (Equation 3)
【0069】で表すことができる。位相回転手段110
としても、図8に示すように複素乗算は不要で、加算と
減算と定数の乗算で実現できる。複素乗算手段4と、位
相回転手段110の出力は選択手段7に入力され、領域
判定手段5の領域判定結果により、図7に示すように、
遅延検波信号が8つの領域のうち、領域aのとき、すな
わちy<x・tan(π/8) かつ y>−x・ta
n(π/8) のときは、遅延検波信号の直交成分
(y)を周波数ずれ信号とし、領域bのとき、すなわち
y>x・cot(π/8) かつ y>−x・cot
(π/8) のときは、遅延検波信号の同相成分(x)
・(−1)を周波数ずれ信号とし、領域cのとき、すな
わちy>x・tan(π/8) かつ y<−x・ta
n(π/8) のときは、遅延検波信号の直交成分
(y)・(−1)を周波数ずれ信号とし、領域dのと
き、すなわちy<x・cot(π/8) かつ y<−
x・cot(π/8) のときは、遅延検波信号の同相
成分(x)を周波数ずれ信号とし、領域eのとき、すな
わちy>x・tan(π/8) かつ y<x・cot
(π/8) のときは、π/4位相回転後の遅延検波信
号の同相成分(x)・(−1)を周波数ずれ信号とし、
領域fのとき、すなわちy>−x・tan(π/8)
かつ y<−x・cot(π/8) のときは、π/4
位相回転後の遅延検波信号の直交成分(y)・(−1)
を周波数ずれ信号とし、領域gのとき、すなわちy<x
・tan(π/8) かつ y>x・cot(π/8)
のときは、π/4位相回転後の遅延検波信号の同相成
分(x)を周波数ずれ信号とし、領域hのとき、すなわ
ちy<−x・tan(π/8) かつ y>−x・co
t(π/8)のときは、π/4位相回転後の遅延検波信
号の同相成分(y)を周波数ずれ信号として出力する。Can be represented by Phase rotation means 110
However, as shown in FIG. 8, complex multiplication is unnecessary, and can be realized by addition, subtraction, and constant multiplication. The outputs of the complex multiplication means 4 and the phase rotation means 110 are input to the selection means 7 and, based on the area determination result of the area determination means 5, as shown in FIG.
When the differential detection signal is in the area a among the eight areas, that is, y <x · tan (π / 8) and y> −x · ta
When n (π / 8), the quadrature component (y) of the differential detection signal is used as a frequency shift signal, and in the region b, that is, y> x · cot (π / 8) and y> −x · cot
(Π / 8), the in-phase component (x) of the differential detection signal
(-1) is a frequency shift signal, and in a region c, that is, y> x · tan (π / 8) and y <−x · ta
When n (π / 8), the quadrature component (y) · (−1) of the differential detection signal is used as a frequency shift signal, and in the region d, that is, y <x · cot (π / 8) and y <−.
In the case of x · cot (π / 8), the in-phase component (x) of the differential detection signal is used as a frequency shift signal, and in the region e, that is, y> x · tan (π / 8) and y <x · cot
In the case of (π / 8), the in-phase component (x) · (−1) of the delayed detection signal after the π / 4 phase rotation is used as a frequency shift signal,
In the case of the area f, that is, y> −x · tan (π / 8)
And when y <−x · cot (π / 8), π / 4
Quadrature component (y) · (−1) of differential detection signal after phase rotation
Is a frequency shift signal, and in a region g, that is, y <x
Tan (π / 8) and y> x · cot (π / 8)
In the case of, the in-phase component (x) of the delayed detection signal after the π / 4 phase rotation is used as a frequency shift signal, and in a region h, that is, y <−x · tan (π / 8) and y> −x · co
At t (π / 8), the in-phase component (y) of the delayed detection signal after the π / 4 phase rotation is output as a frequency shift signal.
【0070】以上により、周波数ずれを求めるのに、直
交座標から極座標に変換する複雑な変換をすることな
く、周波数ずれを検出することが可能になる。As described above, it is possible to detect a frequency shift without performing a complicated conversion from the rectangular coordinates to the polar coordinates in order to obtain the frequency shift.
【0071】これによって得られた、周波数ずれ信号は
図16に示すようにディジタルAFCとして、ループフ
ィルタ41、数値演算発振回路(NCO)42、sin
変換手段43,cos変換手段44、複素乗算器14を
介して周波数制御が可能である共に、図17に示すよう
に準同期直交検波の局部発振回路を電圧制御発振器(V
CO)とすることにより、ループフィルタ41、D/A
変換器70、準同期直交検波を介したAFCが可能とな
る。The frequency shift signal obtained in this way is converted into a digital AFC as shown in FIG. 16 as a loop filter 41, a numerical operation oscillator (NCO) 42, a sin
The frequency can be controlled via the conversion means 43, the cos conversion means 44, and the complex multiplier 14, and the local oscillation circuit for quasi-synchronous quadrature detection is connected to a voltage controlled oscillator (V
CO), the loop filter 41, D / A
The converter 70 enables AFC via quasi-synchronous quadrature detection.
【0072】なお、領域判定手段5における領域判定に
ついて、遅延検波出力の絶対値をとり直交座標の第1象
現(x≧0かつy≧0)において y=x・tan(π
/8)、y=x・cot(π/8)の直線で0からπ/
2までの範囲の領域を判定し、遅延検波出力x、yの符
号を用いて座標の象現を判定することにより、8つの領
域を判定することができることは言うまでもない。In the area judgment by the area judgment means 5, the absolute value of the delay detection output is taken, and y = x · tan (π) in the first quadrant (x ≧ 0 and y ≧ 0) of the orthogonal coordinates.
/ 8), y = x · cot (π / 8) on a straight line from 0 to π /
It is needless to say that eight regions can be determined by determining the region of up to 2 and determining the coordinate representation using the signs of the differential detection outputs x and y.
【0073】また、領域判定に用いるtan(π/8)
及びcot(π/8)の値についは、有限値にしても問
題にならないことは言うまでもない。Also, tan (π / 8) used for area determination
It goes without saying that there is no problem even if the values of and cot (π / 8) are finite.
【0074】(実施の形態4)図9は本発明の第4の実
施の形態を示したものであり、1a,1bは8PSK信
号を直交検波して得られた同相成分(I)、直交成分
(Q)の等価低域信号入力端子、2は1シンボル遅延手
段、3は複素共役生成手段、4は複素乗算手段、5は領
域判定手段、106a,106b,116a,116b
は絶対値生成手段、107,117は引き算手段、10
8,118は符号反転手段、7は選択手段、110はπ
/4位相回転手段、8は周波数ずれ信号出力端子であ
る。以下にその動作を説明する。(Embodiment 4) FIG. 9 shows a fourth embodiment of the present invention, wherein 1a and 1b show an in-phase component (I) and a quadrature component obtained by quadrature detection of an 8PSK signal. (Q) Equivalent low band signal input terminal, 2 is one symbol delay means, 3 is complex conjugate generation means, 4 is complex multiplication means, 5 is area determination means, 106a, 106b, 116a, 116b
Are absolute value generation means, 107 and 117 are subtraction means, 10
8, 118 are sign inversion means, 7 is selection means, 110 is π
A / 4 phase rotation means 8 is a frequency shift signal output terminal. The operation will be described below.
【0075】8PSK信号を直交検波して得られた同相
成分(I)、直交成分(Q)の等価低域信号は1a,1
bの入力端子に入力される。このI,Qの等価低域信号
はディジタル化されており、等価低域信号はそれぞれ複
素数の実部及び虚部と見なされる。この等価低域信号は
衛星アンテナにおける周波数変換器(図示せず)等に起
因する周波数ずれを含んでいる。The equivalent low-frequency signals of the in-phase component (I) and the quadrature component (Q) obtained by quadrature detection of the 8PSK signal are 1a, 1
is input to the input terminal b. The I and Q equivalent low band signals are digitized, and the equivalent low band signals are regarded as a real part and an imaginary part of a complex number, respectively. This equivalent low-frequency signal includes a frequency shift caused by a frequency converter (not shown) in the satellite antenna or the like.
【0076】周波数ずれを含んだI,Qの等価低域信号
は、1シンボル期間での遅延検波が行われる。遅延検波
を構成するのは1シンボル遅延手段2と、複素共役生成
手段3と、複素乗算手段4とで構成され、現在の等価低
域信号と、1シンボル前の等価低域信号の複素共役信号
とが複素乗算される。これを式で表すと(数2)のよう
になる。The I and Q equivalent low-frequency signals including the frequency shift are subjected to delay detection in one symbol period. The delay detection is composed of a one-symbol delay means 2, a complex conjugate generation means 3, and a complex multiplication means 4, and is a complex conjugate signal of the current equivalent low-band signal and the equivalent low-band signal of one symbol before. And are complex multiplied. When this is expressed by an equation, it becomes as shown in (Equation 2).
【0077】この(数2)より、等価低域信号に周波数
ずれが無ければ遅延検波出力の位相状態は図12の位相
状態図の●に示すようにπ/4・n(n=0〜7)にあ
る。しかし、周波数ずれΔfがあると2π・Δf・Ts
の分、位相が●よりずれることになる。From this (Equation 2), if there is no frequency shift in the equivalent low-frequency signal, the phase state of the differential detection output is π / 4 · n (n = 0 to 7) as shown by ● in the phase diagram of FIG. )It is in. However, if there is a frequency shift Δf, 2π · Δf · Ts
, The phase is shifted from ●.
【0078】さてこの遅延検波出力より周波数ずれを求
めるのに、直交座標から極座標に変換することなく行う
ために、直交座標上で周波数ずれとほぼ比例する値を選
ぶ必要がある。Now, in order to obtain the frequency shift from the delayed detection output without converting from the rectangular coordinates to the polar coordinates, it is necessary to select a value substantially proportional to the frequency shift on the rectangular coordinates.
【0079】そこで、図9(a)に示すように遅延検波
出力結果を (nπ/4)±(π/8)(n=0,1,2,3,4,
5,6,7) で8つの領域に分け、そのうち座標軸を含まない領域、
すなわち (π/4)+(nπ/2)±π/8 内の領域(n=
0,1,2,3)) の領域e,領域f,領域g,領域hの各領域に入ったと
きに、図4(b)に示すように遅延検波出力の同相成分
(x)と、直交成分(y)との差が周波数ずれとほぼ比
例した信号とみなすことが出来る。Therefore, as shown in FIG. 9A, the delay detection output result is expressed as (nπ / 4) ± (π / 8) (n = 0, 1, 2, 3, 4,
5,6,7) to divide into 8 areas, of which area does not include coordinate axes,
That is, the region (n = (n / 4) + (nπ / 2) ± π / 8)
0, 1, 2, 3)), when entering each of the regions e, f, g, and h, as shown in FIG. 4B, the in-phase component (x) of the differential detection output, The difference from the orthogonal component (y) can be regarded as a signal substantially proportional to the frequency shift.
【0080】例えば、e領域(π/4±π/8内の領
域)であると、π/4を境に(π/4)+(π/8)ま
でが周波数が進んでおり、遅延検波出力の同相成分
(x)と、直交成分(y)との差(|y|−|x|)は
正になり、周波数の進みが大きくなるとともにその値も
大きくなる。一方、π/4を境に(π/4)−(π/
8)までが周波数が遅れており、遅延検波出力の同相成
分(x)と、直交成分(y)との差(|y|−|x|)
は負になり、周波数の遅れが大きくなると共にその値も
小さくなる。For example, in the e region (region within π / 4 ± π / 8), the frequency is advanced from (π / 4) to (π / 8) at the boundary of π / 4, and the delay detection is performed. The difference (| y |-| x |) between the in-phase component (x) and the quadrature component (y) of the output becomes positive, and the value increases as the frequency advance increases. On the other hand, at the boundary of π / 4, (π / 4) − (π /
The frequency is delayed up to 8), and the difference (| y | − | x |) between the in-phase component (x) and the quadrature component (y) of the differential detection output
Becomes negative, and its value decreases as the frequency delay increases.
【0081】このように領域e,領域f,領域g,領域
hの時、その周波数ずれに比例する値として、図9
(a)に示すように、それぞれ (|y|−|x|)、−(|y|−|x|) (|y|−|x|)、−(|y|−|x|) を周波数ずれ信号として出力する。As described above, in the case of the region e, the region f, the region g, and the region h, the value proportional to the frequency shift is shown in FIG.
As shown in (a), (| y |-| x |),-(| y |-| x |), (| y |-| x |) and-(| y |-| x |) Output as a frequency shift signal.
【0082】一方、8つの領域の内、座標軸を含む領
域、すなわち (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) 領域a,領域b,領域c,領域dの各領域にある時、図
10(b)に示すように遅延検波信号をπ/4だけ位相
回転させることにより、その信号の同相成分(x)、直
交成分(y)の差もまた、周波数ずれとほぼ比例した信
号とみなすことが出来る。On the other hand, of the eight regions, a region including the coordinate axis, that is, a region (n = 0, 1, 1) within (nπ / 2) ± (π / 8)
2, 3) When in the regions a, b, c and d, the differential detection signal is rotated by π / 4 as shown in FIG. The difference between (x) and the orthogonal component (y) can also be regarded as a signal substantially proportional to the frequency shift.
【0083】そのために、遅延検波出力は領域判定手段
5に入力され、図10(a)に示すように、直交座標系
で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により遅延検波信号を8つの領域で領域判定を行
い、また、遅延検波出力(x),(y)は絶対値生成手
段106a、106b、引き算手段107、及び符号反
転手段108により、 (π/4)+(nπ/2)±(π/8) 内の領域(n
=0,1,2,3) における周波数ずれに比例する値となる(|y|−|x
|)及び、−(|y|−|x|)を生成するとともに、
遅延検波出力(x),(y)は位相回転手段110によ
り、π/4だけ位相が回転され、その出力は絶対値生成
手段116a、116b、引き算手段117、及び符号
反転手段118により、 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) における周波数ずれに比例する値となる(|y|−|x
|)及び、−(|y|−|x|)を生成し、選択手段7
に入力される。For this purpose, the differential detection output is input to the area determining means 5, and as shown in FIG. 10A, y = x · tan (π / 8) y = −x · tan (π) in the rectangular coordinate system. / 8) y = x · cot (π / 8) y = −x · cot (π / 8) The area of the differential detection signal is determined in eight areas, and the differential detection output (x), (x y) is calculated by the absolute value generating means 106a and 106b, the subtracting means 107, and the sign inverting means 108 in the area (n) within (π / 4) + (nπ / 2) ± (π / 8).
= 0, 1, 2, 3), and becomes a value proportional to the frequency deviation (| y |-| x
|) And-(| y |-| x |), and
The phases of the differential detection outputs (x) and (y) are rotated by π / 4 by the phase rotation means 110, and the outputs are (nπ) by the absolute value generation means 116a and 116b, the subtraction means 117, and the sign inversion means 118. / 2) region (n = 0, 1, ±) within ± (π / 8)
2,3) becomes a value proportional to the frequency shift (| y | − | x
|) And-(| y |-| x |), and the selecting unit 7
Is input to
【0084】ところで、π/4の位相回転は(数3)で
表す事ができ、位相回転手段110としても図8に示す
ように、複素乗算は不要で、加算と減算と定数の乗算で
実現できる。By the way, the phase rotation of π / 4 can be expressed by (Equation 3). As shown in FIG. 8, the phase rotation means 110 does not require complex multiplication, and is realized by addition, subtraction, and constant multiplication. it can.
【0085】選択手段7は領域判定手段5の領域判定結
果により、図11に示すように、遅延検波信号が8つの
領域のうち、領域eのとき、すなわちy>x・tan
(π/8) かつ y<x・cot(π/8) のと
き、及び、領域gのとき、すなわちy<x・tan(π
/8) かつ y>x・cot(π/8) のときは、
遅延検波信号の(|y|−|x|)を周波数ずれ信号と
し、領域fのとき、すなわちy>−x・tan(π/
8) かつ y<−x・cot(π/8) のとき及
び、領域hのとき、すなわちy<−x・tan(π/
8) かつ y>−x・cot(π/8) のときは遅
延検波信号の−(|y|−|x|)を周波数ずれ信号と
し、領域aのとき、すなわちy<x・tan(π/8)
かつ y>−x・tan(π/8) のとき及び、領
域cのとき、すなわちy>x・tan(π/8) かつ
y<−x・tan(π/8) のときは、π/4位相
回転後の遅延検波信号の(|y|−|x|)を周波数ず
れ信号とし、領域bのとき、すなわちy>x・cot
(π/8) かつ y>−x・cot(π/8) のと
き及び、領域dのとき、すなわちy<x・cot(π/
8) かつ y<−x・cot(π/8) のときは、
π/4位相回転後の遅延検波信号の遅延検波信号の−
(|y|−|x|)を周波数ずれ信号として出力する。As shown in FIG. 11, the selecting means 7 determines, based on the area determination result of the area determining means 5, when the differential detection signal is in the area e among eight areas, ie, y> xtan.
(Π / 8) and y <x · cot (π / 8) and in the region g, ie, y <x · tan (π
/ 8) and y> x · cot (π / 8),
(| Y |-| x |) of the differential detection signal is used as a frequency shift signal, and in the region f, that is, y> −x · tan (π /
8) and y <−x · cot (π / 8) and in the region h, ie, y <−x · tan (π /
8) And when y> −x · cot (π / 8), − (| y | − | x |) of the differential detection signal is used as a frequency shift signal, and in the region a, that is, y <x · tan (π). / 8)
When y> −x · tan (π / 8) and in the region c, that is, when y> x · tan (π / 8) and y <−x · tan (π / 8), π / (| Y |-| x |) of the differential detection signal after the four-phase rotation is used as a frequency shift signal, and in a region b, that is, y> x · cot
(Π / 8) and y> −x · cot (π / 8) and in the region d, ie, y <x · cot (π /
8) And when y <−x · cot (π / 8),
-of the delayed detection signal of the delayed detection signal after the π / 4 phase rotation
(| Y |-| x |) is output as a frequency shift signal.
【0086】以上により、周波数ずれを求めるのに、直
交座標から極座標に変換する複雑な変換をすることな
く、周波数ずれを検出することが可能になる。As described above, it is possible to detect a frequency shift without performing a complicated conversion from orthogonal coordinates to polar coordinates in order to obtain the frequency shift.
【0087】これによって得られた、周波数ずれ信号は
図16に示すようにディジタルAFCとして、ループフ
ィルタ41、数値演算発振回路(NCO)42、sin
変換手段43、cos変換手段44、複素乗算器14を
介して周波数制御が可能である共に、図17に示すよう
に準同期直交検波の局部発振回路を電圧制御発振器(V
CO)とすることにより、ループフィルタ41、D/A
変換器70、準同期直交検波を介したAFCが可能とな
る。The frequency shift signal obtained as described above is converted into a digital AFC as shown in FIG. 16 as a loop filter 41, a numerical operation oscillation circuit (NCO) 42,
The frequency can be controlled via the conversion means 43, the cos conversion means 44, and the complex multiplier 14, and the local oscillation circuit for quasi-synchronous quadrature detection is connected to a voltage controlled oscillator (V
CO), the loop filter 41, D / A
The converter 70 enables AFC via quasi-synchronous quadrature detection.
【0088】なお、領域判定手段5における領域判定に
ついて、遅延検波出力の絶対値をとり直交座標の第1象
現(x≧0かつy≧0)において y=x・tan(π
/8)、y=x・cot(π/8)の直線で0からπ/
2までの範囲の領域を判定し、遅延検波出力x、yの符
号を用いて座標の象現を判定することにより、8つの領
域を判定することができることは言うまでもない。In the area judgment by the area judgment means 5, the absolute value of the differential detection output is taken, and y = x · tan (π) in the first quadrant (x ≧ 0 and y ≧ 0) of the orthogonal coordinates.
/ 8), y = x · cot (π / 8) on a straight line from 0 to π /
It is needless to say that eight regions can be determined by determining the region of up to 2 and determining the coordinate representation using the signs of the differential detection outputs x and y.
【0089】また、領域判定に用いるtan(π/8)
及びcot(π/8)の値についは、有限値にしても問
題にならないことは言うまでもない。Also, tan (π / 8) used for area determination
It goes without saying that there is no problem even if the values of and cot (π / 8) are finite.
【0090】(実施の形態5)図13は本発明の第5の
実施の形態を示したものであり、1a,1bは周波数ず
れを含んだI,Qの等価低域信号入力端子、2は1シン
ボル遅延手段、3は複素共役生成手段、4は複素乗算手
段、5は領域判定手段、6a,6bは符号反転手段、7
は選択手段、8は周波数ずれ信号出力端子、9は判定条
件切り替え手段である。(Embodiment 5) FIG. 13 shows a fifth embodiment of the present invention. Reference numerals 1a and 1b denote I and Q equivalent low-frequency signal input terminals including a frequency shift, and 2 denotes a terminal. 1 symbol delay means, 3 is a complex conjugate generating means, 4 is a complex multiplying means, 5 is a region determining means, 6a and 6b are sign inverting means, 7
Is a selection means, 8 is a frequency shift signal output terminal, and 9 is a judgment condition switching means.
【0091】実施の形態1で説明した構成で示したもの
と同じ記号のブロックは同じ動作を行うため、その説明
は割愛する。さて、遅延検波出力より周波数ずれを求め
るのに、直交座標から極座標に変換することなく行うの
には、直交座標上で周波数ずれとほぼ比例する値を選ん
でやればよい。実施の形態1の8PSKの場合には、図
2に示すように検波出力結果を、8つの領域に分け、そ
のうち座標軸を含む領域a,領域b,領域c,領域dの
各領域に入ったときは、周波数ずれに比例する量とし
て、それぞれ検波出力の直交成分または同相成分である
y,−x,−y,xを周波数ずれ信号とし、それ以外の
ときは出力しないようにしていた。これを複数の位相変
調でも対応させるためには、まず、領域判定切り替え手
段9により、領域判定直線を切り替える。例えば、QP
SK受信時ではy=x、y=−xの直線で4つの領域に
分け、8PSK受信時では y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=―x・cot(π/8) の直線により遅延検波信号を8つの領域に分ける。そし
て、図13(b)に示したように、それぞれの領域のう
ち領域判定手段の出力により、遅延検波信号が直交座標
の座標軸を含む領域にあるときのみ、遅延検波信号の同
相成分(x)、または直交成分(y)を周波数ずれに比
例する量として、その周波数ずれと極性を合わせて出力
することによって、複数の位相変調に対して、直交座標
から極座標に変換する複雑な変換をすることなく、周波
数ずれを検出することが可能になる。Blocks having the same reference numerals as those shown in the configuration described in the first embodiment perform the same operations, and thus description thereof will be omitted. Now, in order to obtain the frequency shift from the delayed detection output without converting the rectangular coordinates to the polar coordinates, a value substantially proportional to the frequency shift on the rectangular coordinates may be selected. In the case of 8PSK according to the first embodiment, when the detection output result is divided into eight regions as shown in FIG. 2, when the detection output result enters each of regions a, b, c, and d including the coordinate axes. Is a variable proportional to the frequency shift, and sets the quadrature component or the in-phase component of the detection output, y, -x, -y, x, as the frequency shift signal, and does not output the signal at other times. In order to make this correspond to a plurality of phase modulations, first, the area determination switching means 9 switches the area determination straight line. For example, QP
At the time of SK reception, it is divided into four regions by a straight line of y = x, y = −x, and at the time of 8PSK reception, y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) The differential detection signal is divided into eight regions by a straight line of y = −x · cot (π / 8). Then, as shown in FIG. 13 (b), the in-phase component (x) of the delayed detection signal is obtained only when the delayed detection signal is located in the area including the coordinate axes of the rectangular coordinates, based on the output of the area determination means among the respective areas. , Or a quadrature component (y) as an amount proportional to the frequency shift and outputting the same with the frequency shift and the polarity, thereby performing a complex conversion for converting a plurality of phase modulations from orthogonal coordinates to polar coordinates. Frequency deviation can be detected.
【0092】これによって得られた、周波数ずれ信号は
図16に示すようにディジタルAFCとして、ループフ
ィルタ41、数値演算発振回路(NCO)42、sin
変換手段43,cos変換手段44、複素乗算器14を
介して周波数制御が可能である共に、図17に示すよう
に準同期直交検波の局部発振回路を電圧制御発振器(V
CO)とすることにより、ループフィルタ41、D/A
変換器70、準同期直交検波を介したAFCが可能とな
る。The frequency shift signal obtained in this way is converted into a digital AFC as shown in FIG. 16 as a loop filter 41, a numerical operation oscillator (NCO) 42, a sin
The frequency can be controlled via the conversion means 43, the cos conversion means 44, and the complex multiplier 14, and the local oscillation circuit for quasi-synchronous quadrature detection is connected to a voltage controlled oscillator (V
CO), the loop filter 41, D / A
The converter 70 enables AFC via quasi-synchronous quadrature detection.
【0093】なお、領域判定手段5における領域判定に
ついて、遅延検波出力の絶対値をとり直交座標の第1象
現(x≧0かつy≧0)において y=x・tan(π
/8)、y=x・cot(π/8)の直線で0からπ/
2までの範囲の領域を判定し、遅延検波出力x、yの符
号を用いて座標の象現を判定することにより、8つの領
域を判定することができることは言うまでもない。In the area judgment by the area judgment means 5, the absolute value of the delayed detection output is taken and y = x · tan (π) in the first quadrant (x ≧ 0 and y ≧ 0) of the orthogonal coordinates.
/ 8), y = x · cot (π / 8) on a straight line from 0 to π /
It is needless to say that eight regions can be determined by determining the region of up to 2 and determining the coordinate representation using the signs of the differential detection outputs x and y.
【0094】また、領域判定に用いるtan(π/8)
及びcot(π/8)の値についは、有限値にしても問
題にならないことは言うまでもない。Also, tan (π / 8) used for area determination
It goes without saying that there is no problem even if the values of and cot (π / 8) are finite.
【0095】[0095]
【発明の効果】本発明の周波数ずれ検出方法および周波
数ずれ検出装置においては、8PSKのAFCにおける
周波数ずれ検出が、直交座標から極座標への変換を行う
ことなく、簡単な方法並びに簡単な回路構成で実現でき
る。According to the frequency shift detecting method and the frequency shift detecting apparatus of the present invention, the frequency shift detection in the 8PSK AFC can be performed by a simple method and a simple circuit configuration without performing conversion from rectangular coordinates to polar coordinates. realizable.
【0096】また、本発明の周波数ずれ検出方法および
周波数ずれ検出装置においては、複数の種類の位相変調
に対応できる周波数ずれ検出方法並びに装置を回路構成
で実現できる。Further, in the frequency shift detecting method and the frequency shift detecting apparatus according to the present invention, the frequency shift detecting method and apparatus which can cope with a plurality of types of phase modulation can be realized by a circuit configuration.
【図1】本発明の第1の実施の形態である周波数ずれ検
出装置の構成図FIG. 1 is a configuration diagram of a frequency shift detecting device according to a first embodiment of the present invention;
【図2】同周波数ずれ検出装置における領域判定とそれ
に伴う選択手段の出力を表した図FIG. 2 is a diagram showing an area determination and an output of a selection means accompanying the area determination in the frequency shift detecting apparatus.
【図3】本発明の第2の実施の形態である周波数ずれ検
出装置の構成図FIG. 3 is a configuration diagram of a frequency shift detecting device according to a second embodiment of the present invention;
【図4】同周波数ずれ検出装置における領域判定とそれ
に伴う選択手段の出力を表した図FIG. 4 is a diagram showing an area determination and an output of a selection means accompanying the area determination in the frequency shift detecting apparatus.
【図5】本発明の第3の実施の形態である周波数ずれ検
出装置の構成図FIG. 5 is a configuration diagram of a frequency shift detecting device according to a third embodiment of the present invention;
【図6】同周波数ずれ検出装置における領域判定を示す
位相状態図FIG. 6 is a phase state diagram showing a region determination in the frequency shift detecting device.
【図7】同周波数ずれ検出装置における領域判定により
選択手段の出力を表した図FIG. 7 is a diagram showing an output of a selection unit based on a region determination in the frequency shift detection device.
【図8】本発明の周波数ずれ検出装置のπ/4位相回転
手段の構成図FIG. 8 is a configuration diagram of a π / 4 phase rotation unit of the frequency deviation detection device of the present invention.
【図9】本発明の第4の実施の形態である周波数ずれ検
出装置の構成図FIG. 9 is a configuration diagram of a frequency shift detecting device according to a fourth embodiment of the present invention.
【図10】同周波数ずれ検出装置における領域判定を示
す位相状態図FIG. 10 is a phase state diagram showing area determination in the frequency shift detecting device.
【図11】同周波数ずれ検出装置における領域判定によ
り選択手段の出力を表した図FIG. 11 is a diagram showing an output of a selection unit based on area determination in the frequency shift detecting apparatus.
【図12】8PSKの遅延検波出力信号の位相状態を示
す図FIG. 12 is a diagram illustrating a phase state of an 8PSK differential detection output signal.
【図13】本発明の第5の実施の形態である周波数ずれ
検出装置の構成図FIG. 13 is a configuration diagram of a frequency shift detecting device according to a fifth embodiment of the present invention.
【図14】従来のQPSK復調システムの構成を示す図FIG. 14 is a diagram showing a configuration of a conventional QPSK demodulation system.
【図15】QPSK及び8PSKの位相状態を表した図FIG. 15 is a diagram showing phase states of QPSK and 8PSK.
【図16】本発明の周波数ずれ検出装置を用いた自動周
波数制御の構成図FIG. 16 is a configuration diagram of automatic frequency control using the frequency deviation detecting device of the present invention.
【図17】本発明の周波数ずれ検出装置を用いた自動周
波数制御の構成図FIG. 17 is a configuration diagram of automatic frequency control using the frequency deviation detection device of the present invention.
1a,1b 等価低域信号入力端子 2 1シンボル遅延手段 3 複素共役生成手段 4 複素乗算手段 5 領域判定手段 6a,6b,6c,6d,108,118 符号反転手
段 7 選択手段 8 周波数ずれ信号出力端子 9 判定領域切り替え手段 10 QPSK変調信号入力端子 11 準同期直交検波手段、 12a,12b ローパスフィルタ 13a,13b A/D変換器 14 AFCの為の複素乗算器 15a,15b ロールオフフィルタ 16 搬送波再生のための複素乗算器 17 データ判定回路、 18a,18b I,Qデータ出力端子 20 直交座標−極座標 変換手段 21 周波数誤差検出手段 106a,106b,116a,116b 絶対値生成
手段 107、117 引き算手段1a, 1b Equivalent low-frequency signal input terminal 2 1 symbol delay means 3 Complex conjugate generation means 4 Complex multiplication means 5 Area determination means 6a, 6b, 6c, 6d, 108, 118 Sign inversion means 7 Selection means 8 Frequency shift signal output terminal Reference Signs List 9 decision area switching means 10 QPSK modulation signal input terminal 11 quasi-synchronous quadrature detection means 12a, 12b low-pass filter 13a, 13b A / D converter 14 complex multiplier for AFC 15a, 15b roll-off filter 16 for carrier wave reproduction 17 Multiplier 17 Data decision circuit, 18a, 18b I, Q data output terminal 20 Cartesian coordinate-polar coordinate conversion means 21 Frequency error detection means 106a, 106b, 116a, 116b Absolute value generation means 107, 117 Subtraction means
───────────────────────────────────────────────────── フロントページの続き (72)発明者 大本 紀顕 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Noriaki Omoto 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.
Claims (12)
たI、Qの等価低域信号を連続したシンボル間で遅延検
波を施し、その遅延検波信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で示される8つの領域のどの領域にあるのか領域判定を
行い、前記遅延検波信号が、前記8つの領域のうち、 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波信号の同相または直交
成分を周波数ずれ信号とみなすことを特徴とする周波数
ずれ検出方法。An I and Q equivalent low band signal obtained by quadrature detection of an 8-phase phase modulated signal is subjected to delay detection between successive symbols, and the phase of the delayed detection signal is (nπ / 4). ± (π / 8) (n = 0, 1, 2, 3,
A determination is made as to which of the eight regions represented by (4,5,6,7) is present, and the differential detection signal is obtained by comparing the (nπ / 2) ± (π / 8) Area (n = 0, 1,
A frequency shift detection method, wherein the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal only when the signal is in (2) or (3).
る直交検波手段と、前記直交検波手段の出力であるI、
Qの等価低域信号を入力として連続したシンボル間で遅
延検波を行う遅延検波手段と、前記遅延検波手段で得ら
れた遅延検波信号(同相成分(x)、直交成分(y))
を入力として、その位相について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号の
位相が、前記8つの領域のうち直交座標軸を含む領域 (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときにのみ、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力する選択手段とを備えることを特徴とする周波数ず
れ検出装置。2. Quadrature detection means for performing quadrature detection on an inputted eight-phase modulation signal, and I, which is an output of the quadrature detection means,
A delay detection means for performing delay detection between consecutive symbols using an equivalent low-frequency signal of Q as an input, and a delay detection signal (in-phase component (x), quadrature component (y)) obtained by the delay detection means
, And y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot ( area determining means for performing area determination by dividing the area into eight areas using a straight line of (π / 8), and a phase (nπ / 2) Region within ± (π / 8) (n = 0, 1,
2. A frequency shift detecting apparatus, comprising: a selector that outputs an in-phase component (x) or a quadrature component (y) of the differential detection output signal as a frequency shift signal only when the signal is in the second or third mode.
る直交検波手段と、直交検波手段の出力であるI、Qの
等価低域信号を入力として連続したシンボル間で遅延検
波を行う遅延検波手段と、前記遅延検波手段で得られた
遅延検波信号(同相成分(x)、直交成分(y))を入
力として、その位相について、直交座標系で、 y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号の
位相が、前記8つの領域のうち直交座標軸を含む領域 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときにのみ、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力し、それ以外の領域にあるときは前に領域判定をし
た周数ずれ信号を保持する選択手段とを備えることを特
徴とする周波数ずれ検出装置。3. A quadrature detection means for quadrature detection of an inputted eight-phase modulation signal, and a delay detection for performing a delay detection between consecutive symbols by inputting I and Q equivalent low band signals output from the quadrature detection means. Means and the delayed detection signal (in-phase component (x), quadrature component (y)) obtained by the delay detection means, and the phase thereof is expressed in a quadrature coordinate system as: y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) Area determination means for performing area determination by dividing the area into eight areas, From the output of the area determination means, the phase of the differential detection signal is set to an area (nπ / 2) ± (π / 8) including an orthogonal coordinate axis among the eight areas (n = 0, 1,
The in-phase component (x) or the quadrature component (y) of the differential detection output signal is output as a frequency shift signal only when the differential detection output signal is in (2, 3). A frequency deviation detection device, comprising: a selection unit for holding a frequency deviation signal.
たI、Qの等価低域信号を連続したシンボル間で遅延検
波を施し、その遅延検波信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,4,5,6,7) で示される8つの領域のどの領域にあるか領域判定を行
い、前記遅延検波信号が、前記8つの領域のうち、 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号の同相成分(x)と直
交成分(y)との差を周波数ずれ信号とみなすことを特
徴とする周波数ずれ検出方法。4. An I and Q equivalent low band signal obtained by quadrature detection of an 8-phase phase modulated signal is subjected to delay detection between successive symbols, and the phase of the delayed detection signal is (nπ / 4). An area determination is made as to which of the eight areas represented by ± (π / 8) (n = 0, 1, 2, 3, 4, 5, 6, 7), and the differential detection signal In the two regions, ((π / 4) + (nπ / 2)) ± (π / 8) the region (n = 0,1,2,3), the in-phase component of the differential detection signal A frequency shift detection method, wherein a difference between (x) and the orthogonal component (y) is regarded as a frequency shift signal.
る直交検波手段と、前記直交検波手段の出力であるI、
Qの等価低域信号を入力として連続したシンボル間で遅
延検波を行う遅延検波手段と、前記遅延検波手段で得ら
れた遅延検波信号(同相成分(x)、直交成分(y))
を入力として、その位相について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含まな
い領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときにのみ、前記遅延検波信号の同相成分(x)
と直交成分(y)との差を周波数ずれ信号として出力す
る選択手段とを備えることを特徴とする周波数ずれ検出
装置。5. A quadrature detection means for quadrature detection of an inputted eight-phase modulation signal, and I, which is an output of said quadrature detection means,
A delay detection means for performing delay detection between consecutive symbols using an equivalent low-frequency signal of Q as an input, and a delay detection signal (in-phase component (x), quadrature component (y)) obtained by the delay detection means
, And y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot ( area determining means for performing area determination by dividing the area into eight areas by a straight line of (π / 8), and an area in which the phase of the differential detection signal is based on an output of the area determining means and which does not include a rectangular coordinate axis among the eight areas. (Π / 4) + (nπ / 2)) ± (π / 8) Only in the region (n = 0, 1, 2, 3), the in-phase component (x) of the differential detection signal
A frequency deviation detection device for outputting a difference between the frequency component and the orthogonal component (y) as a frequency deviation signal.
る直交検波手段と、前記直交検波手段の出力であるI、
Qの等価低域信号を入力として連続したシンボル間で遅
延検波を行う遅延検波手段と、前記遅延検波手段で得ら
れた遅延検波信号(同相成分(x)、直交成分(y))
を入力として、その位相について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含まな
い領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときにのみ、前記遅延検波信号の同相成分(x)
と直交成分(y)との差を周波数ずれ信号として出力
し、それ以外の領域のときは前に領域判定を行った周波
数ずれ信号を保持する選択手段とを備えることを特徴と
する周波数ずれ検出装置。6. A quadrature detecting means for quadrature detecting the input 8-phase phase modulated signal, and I, which is an output of the quadrature detecting means,
A delay detection means for performing delay detection between consecutive symbols using an equivalent low-frequency signal of Q as an input, and a delay detection signal (in-phase component (x), quadrature component (y)) obtained by the delay detection means
, And y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot ( area determining means for performing area determination by dividing the area into eight areas by a straight line of (π / 8), and an area in which the phase of the differential detection signal is based on an output of the area determining means and which does not include a rectangular coordinate axis among the eight areas. (Π / 4) + (nπ / 2)) ± (π / 8) Only in the region (n = 0, 1, 2, 3), the in-phase component (x) of the differential detection signal
Frequency difference detection means for outputting a difference between the frequency shift signal and the orthogonal component (y) as a frequency shift signal, and for other areas, holding a frequency shift signal for which the area determination has been performed before. apparatus.
たI、Qの等価低域信号を連続したシンボル間で遅延検
波を施し、その遅延検波信号について、位相が (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) で示される8つの領域のどの領域にあるのかを領域判定
を行い、前記8つの領域のうち (nπ/2)±(π/8) 内の領域(n=0,1,
2,3) にあるときは、遅延検波信号の同相または直交成分を周
波数ずれ信号とみなし、また前記8つの領域のうち ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号を(π/4)だけ位相
回転させた信号の同相または直交成分を周波数ずれ信号
とみなすことを特徴とする周波数ずれ検出方法。7. An I and Q equivalent low band signal obtained by quadrature detection of an 8-phase phase modulated signal is subjected to delay detection between successive symbols, and the phase of the delayed detection signal is (nπ / 4). ± (π / 8) (n = 0, 1, 2, 3,
A region determination is performed to determine which of the eight regions represented by (4, 5, 6, 7) is located, and a region (n = 0) within (nπ / 2) ± (π / 8) of the eight regions , 1,
2,3), the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal, and ((π / 4) + (nπ / 2)) ± (π / 8) When the differential detection signal is in the region (n = 0, 1, 2, 3), the in-phase or quadrature component of the signal obtained by rotating the differential detection signal by (π / 4) is regarded as a frequency shift signal. Frequency shift detection method.
る直交検波手段と、前記直交検波手段の出力であるI、
Qの等価低域信号を入力として連続したシンボル間で遅
延検波を行う遅延検波手段と、前記遅延検波手段の出力
を入力として遅延検波信号を(π/4)位相回転を行う
位相回転手段と、前記遅延検波手段で得られた遅延検波
信号(同相成分(x)、直交成分(y))を入力とし
て、その位相について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より前記遅延検波信
号の位相が、前記8つの領域のうち直交座標軸を含む領
域 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときは、前記遅延検波出力信号の同相成分
(x)、または直交成分(y)を周波数ずれ信号として
出力し、直交座標軸を含まない領域 ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記位相回転手段で遅延検波信号を(π
/4)だけ位相回転させた信号の同相成分(x)、また
は直交成分(y)を周波数ずれ信号として出力する選択
手段とを備えることを特徴とする周波数ずれ検出装置。8. A quadrature detecting means for quadrature detecting the input eight-phase modulated signal, and I, which is an output of the quadrature detecting means,
Delay detection means for performing delay detection between successive symbols by using an equivalent low-frequency signal of Q as input, phase rotation means for performing (π / 4) phase rotation of the delay detection signal by using an output of the delay detection means as input, The delay detection signal (in-phase component (x), quadrature component (y)) obtained by the above-mentioned delay detection means is input, and its phase is y = x · tan (π / 8) y = −x in the quadrature coordinate system. Tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8) Area determination means for performing area determination by dividing the area into eight areas, and the area determination means From the output of the above, the phase of the differential detection signal is a region (nπ / 2) ± (π / 8) of the eight regions including the orthogonal coordinate axes (n = 0, 1,
2,3), the in-phase component (x) or the quadrature component (y) of the differential detection output signal is output as a frequency shift signal, and the region ((π / 4) + (nπ / 2)) ± (π / 8), the range (n = 0, 1, 2, 3) is satisfied.
/ 4) a selecting means for outputting an in-phase component (x) or a quadrature component (y) of a signal rotated by a phase as a frequency shift signal as a frequency shift signal.
たI、Qの等価低域信号を連続したシンボル間で遅延検
波を施し、その遅延検波信号について、 (nπ/4)±(π/8) (n=0,1,2,3,
4,5,6,7) の8つの領域で領域判定を行い、前記8つの領域のうち ((π/4)+(nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは、前記遅延検波信号の同相成分と直交成分
との差を周波数ずれ信号とみなし、 (nπ/2)±(π/8) 内の領域 (n=0,1,
2,3) にあるときは、前記遅延検波信号を(π/4)だけ位相
回転させた信号の同相成分と直交成分との差を周波数ず
れ信号とみなすことを特徴とする周波数ずれ検出方法。9. An I and Q equivalent low band signal obtained by quadrature detection of an 8-phase phase modulated signal is subjected to delay detection between consecutive symbols, and the (nπ / 4) ± (nπ / 4) ± ( π / 8) (n = 0, 1, 2, 3,
Region determination is performed on eight regions of (4, 5, 6, 7), and a region (n = 0) within ((π / 4) + (nπ / 2)) ± (π / 8) among the eight regions , 1, 2, 3), the difference between the in-phase component and the quadrature component of the differential detection signal is regarded as a frequency shift signal, and the region (n = 0) within (nπ / 2) ± (π / 8) , 1,
2. A frequency shift detection method according to claim 1, wherein a difference between an in-phase component and a quadrature component of the signal obtained by rotating the differential detection signal by (π / 4) is regarded as a frequency shift signal.
する直交検波手段と、前記直交検波手段の出力である
I、Qの等価低域信号を入力として連続したシンボル間
で遅延検波を行う遅延検波手段と、前記遅延検波手段の
出力を入力として前記遅延検波信号を(π/4)位相回
転を行う位相回転手段と、前記遅延検波手段で得られた
遅延検波信号(同相成分(x)、直交成分(y))を入
力として、その位相について、直交座標系で y=x・tan(π/8) y=−x・tan(π/8) y=x・cot(π/8) y=−x・cot(π/8) の直線により8つの領域に分けて領域判定を行う領域判
定手段と、前記領域判定手段の出力より遅延検波信号
が、8つの領域のうち直交座標軸を含まない領域 ((π/4+nπ/2))±(π/8) 内の領域
(n=0,1,2,3) にあるときは遅延検波信号の同相成分(x)と直交成分
(y)との差を周波数ずれ信号として出力し、直交座標
軸を含む領域 ((nπ/2)±(π/8) 内の領域 (n=0,
1,2,3) にあるときは、前記位相回転手段で前記遅延検波信号
(π/4)だけ位相回転させた信号の同相成分(x)と
直交成分(y)との差を周波数ずれ信号として出力する
選択手段とを備えることを特徴とする周波数ずれ検出装
置。10. A quadrature detector for performing quadrature detection on an input 8-phase phase modulated signal, and a delay for performing delay detection between consecutive symbols using I and Q equivalent low-frequency signals output from the quadrature detector as inputs. Detection means, phase rotation means for performing the (π / 4) phase rotation of the delayed detection signal by using the output of the delay detection means as an input, and a delayed detection signal (in-phase component (x), With the quadrature component (y)) as input, the phase is calculated in the orthogonal coordinate system as follows: y = x · tan (π / 8) y = −x · tan (π / 8) y = x · cot (π / 8) y = −x · cot (π / 8), a region determination unit that performs region determination by dividing the region into eight regions, and a delayed detection signal from the output of the region determination unit that does not include the orthogonal coordinate axis among the eight regions. Within the area ((π / 4 + nπ / 2)) ± (π / 8) Area
When (n = 0, 1, 2, 3), the difference between the in-phase component (x) and the quadrature component (y) of the differential detection signal is output as a frequency shift signal, and the region including the quadrature coordinate axis ((nπ / 2) Region within ± (π / 8) (n = 0,
1, 2, 3), the difference between the in-phase component (x) and the quadrature component (y) of the signal whose phase has been rotated by the delayed detection signal (π / 4) by the phase rotation means is a frequency shift signal. A frequency deviation detecting device, comprising: selecting means for outputting the frequency deviation.
交座標系の領域判定について、領域判定直線を位相変調
の種類によって切り替えるとともに、その領域判定によ
り、遅延検波出力が直交座標の座標軸を含む領域にある
ときは、遅延検波信号の同相または直交成分を周波数ず
れ信号とみなすことを特徴とする請求項1記載の周波数
ずれ検出方法。11. The method according to claim 1, wherein the area detection line is switched in accordance with the type of the phase modulation in the area detection of the differential detection signal in the orthogonal coordinate system, and the area detection causes the differential detection output to include the coordinate axes of the orthogonal coordinates. 2. The frequency shift detecting method according to claim 1, wherein the in-phase or quadrature component of the differential detection signal is regarded as a frequency shift signal.
延検波信号の直交座標系の領域判定手段に、位相変調の
種類に応じて判定領域の切り替えを行う判定領域切り替
え手段を備え、領域判定手段の出力により、遅延検波信
号が直交座標の座標軸を含む領域にあるときのみ、遅延
検波信号の同相成分(x)、または直交成分(y)を周
波数ずれ信号として出力する選択手段、とを備えること
を特徴とする請求項2または請求項3記載の周波数ずれ
検出装置。12. The area determining means according to claim 2, wherein the area determining means of the orthogonal coordinate system of the differential detection signal includes a determination area switching means for switching the determination area according to the type of phase modulation. Selecting means for outputting the in-phase component (x) or the quadrature component (y) of the differential detection signal as a frequency shift signal only when the differential detection signal is in a region including the coordinate axes of the rectangular coordinates. The frequency deviation detecting device according to claim 2 or 3, wherein:
Priority Applications (1)
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---|---|---|---|
JP11220497A JPH10303996A (en) | 1997-04-30 | 1997-04-30 | Method and device for frequency shift detection |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11220497A JPH10303996A (en) | 1997-04-30 | 1997-04-30 | Method and device for frequency shift detection |
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Publication Number | Publication Date |
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JPH10303996A true JPH10303996A (en) | 1998-11-13 |
Family
ID=14580868
Family Applications (1)
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JP11220497A Pending JPH10303996A (en) | 1997-04-30 | 1997-04-30 | Method and device for frequency shift detection |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002019559A1 (en) * | 2000-08-30 | 2002-03-07 | Matsushita Electric Industrial Co., Ltd. | Radio receiver |
US8228970B2 (en) | 2007-06-26 | 2012-07-24 | Nihon Dempa Kogyo Co., Ltd | Signal processing device and wireless apparatus |
-
1997
- 1997-04-30 JP JP11220497A patent/JPH10303996A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002019559A1 (en) * | 2000-08-30 | 2002-03-07 | Matsushita Electric Industrial Co., Ltd. | Radio receiver |
US7139307B2 (en) | 2000-08-30 | 2006-11-21 | Matsushita Electric Industrial, Co., Ltd. | Radio receiver |
US8228970B2 (en) | 2007-06-26 | 2012-07-24 | Nihon Dempa Kogyo Co., Ltd | Signal processing device and wireless apparatus |
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