JP2720745B2 - Signal processing circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal processing circuit for synchronous acquisition and frequency correction in a case where orthogonal spread modulated waves are used in a spread spectrum communication system.

[0002]

2. Description of the Related Art In recent years, a microcell system and a private wireless LAN have been developed.
Practical use of communication networks using wireless networks such as N is being studied, and as one of the communication systems, code division multiple access (Code-Devision-Multip
le-Access: code division multiple access (hereinafter abbreviated as CDMA).

[0003] The spread spectrum system is mainly divided into a direct spread system and a frequency hopping system, and the direct spread system is much higher in frequency (for example, several tens to several hundreds) than an information signal.
This is a method of performing communication by spreading an information signal with a spreading code sequence of (thousands of times).

In the conventional direct spreading method, a two-phase phase modulation (hereinafter, referred to as BPSK) method has been mainly used, but recently, in order to speed up data, an in-phase component (hereinafter, referred to as Ich) and a quadrature component have been used. (Hereinafter referred to as Qch), respectively,
Research on a combined four-phase modulation (hereinafter referred to as QPSK) system has been actively conducted.

[0005] In the spread spectrum system, the influence of the transmission / reception frequency deviation of the carrier at the time of initial synchronization acquisition is an important problem. This is because in other communication systems (for example, FM broadcasting and analog car phones), the transmission / reception frequency deviation is automatically frequency-controlled (Automatically-Frequency-Control: hereinafter referred to as AFC).
, It is possible to perform tracking so that the received signal level is maximized. However, in the spread spectrum method, the desired received signal may be under noise until synchronization acquisition is completed, and AFC cannot be realized in the aforementioned method. It is. Therefore, AFC in the spread spectrum method is
Basically, a method of sweeping within the maximum frequency deviation range is used, but there is a problem that it takes time to acquire synchronization.

Therefore, in the case of the above-described BPSK modulation method, a method of obtaining the magnitude of the envelope regardless of the frequency deviation is used.

FIG. 3 is a block diagram of a conventional BPSK-type synchronization acquisition circuit. In the figure, 310 is a wireless antenna, 320 is a band pass filter (hereinafter referred to as BPF),
330 is an AGC circuit, 341 and 342 are each Ic
h and Qch down mixers, 351 is a local signal source, 352 is a π / 2 phase separator, 361 and 362 are LP
F, 371, 372 are A / D converters, 381, 38
2 is a correlation detector for despreading, 391 and 392 are squarers, 4
00 is an adder, 410 is a synchronization acquisition determination circuit, 420 is a data decoding circuit, 430 is a spreading code generation circuit, and 500 is a code clock recovery circuit.

In the synchronous acquisition circuit shown in FIG. 3, the received signal is quadrature-detected, divided into Ich and Qch, the correlation is detected with the same spreading code sequence, and their outputs are squared and added, whereby the envelope on the phase plane is obtained. The size of the line was determined, and the effect of frequency deviation during synchronization acquisition was removed.

The above operation will be described using equations. Information
No. D_n, Spreading code sequence C = ｛c₀, C ₁... c_M-1｝ (Period =
M), carrier angular frequency ω_c, Transmission / reception frequency deviation Δω, reception
If the noise power in the signal band is N, the received spectrum spread
The signal is

[0010]

(Equation 1)

However,

[0012]

(Equation 2)

It is assumed that: (Number 1) to quadrature detection by exp (j [omega] _c t), a low-pass filter (hereinafter referred to as LPF) signal output after passing through the can,

[0014]

(Equation 3)

[0015]

(Equation 4)

(Equation 3) and (Equation 4) are expressed by a spreading code sequence C ′
When the correlation is detected for each (the same sequence as C but different in phase), a correlation value equal to or greater than a certain value can be obtained only when the phase matches with C ′ = C according to the definition of the spread code sequence. When the phase per one cycle of the spreading sequence due to the frequency deviation can be considered to be substantially constant, the signal levels are Ich and Qch, respectively.

[0017]

(Equation 5)

[0018]

(Equation 6)

## EQU1 ## When the signals of (Equation 5) and (Equation 6) are each squared and added,

[0020]

(Equation 7)

Then, the frequency deviation value Δω disappears and the square value of the envelope remains, so that it is possible to determine the synchronization acquisition.

[0022]

SUMMARY OF THE INVENTION However, QPS
In the case of using the K system, if different spreading code sequences are used for the Ich spreading code sequence (hereinafter referred to as C _I ) and the Qch spreading code sequence (hereinafter referred to as C _Q ), for example, Δω = When it becomes π / 2, correlation detection cannot be obtained. As represented by the above equation, the received signal in this case is

[0023]

(Equation 8)

[0024] (Formula 8) and quadrature detection by exp (j [omega] _c t), the signal output after passing through the LPF, the

[0025]

(Equation 9)

[0026]

(Equation 10)

By substituting Δω = π / 2 into (Equation 9) and (Equation 10),

[0028]

[Equation 11]

[0029]

(Equation 12)

Since the signal including C _I in Ich and the signal including C _Q in Qch disappear before correlation is obtained, the influence of the frequency deviation is eliminated in the method used in the above-described BPSK method. And synchronization acquisition becomes difficult.

[0031]

In order to solve the above-mentioned problems, the present invention provides, as one of them, a quadrature in which an in-phase component and a quadrature component are directly spread on an information signal by using different spreading code sequences. A frequency conversion circuit that converts the spread modulated wave from a received carrier band to a baseband signal in which an in-phase component and a quadrature component are separated, and an in-phase component for both the in-phase component and the quadrature component baseband signal. The first and second despreading correlation detectors with the spreading code sequence of the component, and the third and the second spreading code sequences of the orthogonal component with respect to both the in-phase component and the baseband signal of the quadrature component. 4 despreading correlation detectors, a decoding circuit for decoding data from a plurality of outputs of the four despreading correlators, and a first circuit for squaring the output of the first despreading correlation detector. And a second despreading correlation A second multiplier for squaring the output of the output unit, a first adder for adding the first and second multiplier outputs, and a synchronization acquisition determination according to an output level of the first adder And a first and second despreading correlation detector output, or a third and fourth despreading correlation detector output, or a first despreading correlation detector output, A second adder for adding a fourth despreading correlation detector output,
A subtractor for subtracting the output of the second despreading correlation detector and the output of the third despreading correlation detector, and a combination of any one of the outputs of the second adder and the subtractor And a correction circuit for obtaining a frequency deviation and performing correction at the time of data decoding.

[0032]

According to the present invention, the receiving side separates an in-phase component and a quadrature component by quadrature detection on a QPSK modulated wave using different spreading code sequences for Ich and Qch, respectively. signal or the respect both signal and the spread code sequence C _I transmission Ich transmission Qch
Provides the ability to eliminate the effects of frequency deviation by performing correlation detection with the spread code sequence C _Q of each of the above, and performing synchronization acquisition determination using the sum of squares of the correlation outputs of C _I and C _Q for the same signal. Is what you do.

After synchronization acquisition, a frequency deviation value is obtained from the correlation output of C _I and C _Q and AFC is performed.

The present invention is concretely expressed by an equation. When correlation is detected by C _I ′ and C _Q ′ for each of the Ich signal (Equation 9) and the Qch signal (Equation 10) after quadrature detection, a spread code According to the definition of the series, the cross-correlation C _I × C _Q when the auto-correlation of C _I and C _Q is detected becomes sufficiently small and can be ignored. Also, since noise is averaged in one spreading sequence cycle, when the phase per spreading sequence cycle due to the frequency deviation can be regarded as substantially constant, the output of each correlator is:

[0035]

(Equation 13)

[0036]

[Equation 14]

[0037]

(Equation 15)

[0038]

(Equation 16)

## EQU1 ## Therefore, (Equation 13), (Equation 15)
Are squared and added.

[0040]

[Equation 17]

As in the case of the BPSK modulation, when the phase per one cycle of the spread sequence due to the frequency deviation can be regarded as substantially constant, the synchronous detection can be performed without being affected by the frequency deviation.

Further, in the present invention, after synchronization acquisition, the magnitude of the frequency deviation is obtained using the outputs of the four correlators (Equation 13) to (Equation 16). For example, (Equation 13)
And (Equation 15)

[0043]

(Equation 18)

TanΔωt is obtained. Therefore,

[0045]

[Equation 19]

As a result, Δωt becomes −π / 2 ≦ Δωt
When it is within the range of ≦ π / 2, it can be determined.
(Equation 13), (Equation 14) instead of (Equation 15), (Equation 1)
Δωt can be obtained in the same manner by using 6).

Further, using (Equation 13) to (Equation 16)

[0048]

(Equation 20)

[0049]

(Equation 21)

[0050]

(Equation 22)

As another method, there is a method of obtaining Δωt. The detection method on the receiving side is asynchronous quadrature detection, and the Δω information obtained by the AFC circuit is sent to the data decoding circuit, and (Equation 13)
(Equation 16) can be divided by cosΔωt, and the frequency deviation can be corrected for delay detection. Using Δω obtained by the AFC circuit, the local signal frequency at the time of conversion from the carrier band to the baseband band is corrected from exp (jωct) to exp {j (ωc−Δω) t}, and the absolute synchronous detection is performed. It is also possible to do.

Since the present invention is not affected by the frequency deviation at the time of synchronization acquisition by the above configuration, it is possible to shorten the time until synchronization acquisition in the method of sweeping within the maximum frequency deviation range.

Further, since the magnitude of the frequency deviation can be obtained by using the output from each correlator, the frequency deviation is corrected in the baseband band after the synchronous detection method requiring carrier wave reproduction and the asynchronous quadrature detection. It can be used for any of the differential detection systems.

[0054]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a synchronization acquisition and AFC circuit on the receiving side, which is a main part of the signal processing circuit according to the first embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a radio antenna;
Is a BPF for band-passing a signal received via the radio antenna 10, 30 is an AGC circuit for automatically controlling the output of the BPF 20, 41 and 42 are Ich and Qch down mixers, 51 is a local signal generation source, and 52 is a local signal generation source. π /
Two-phase separators, 61 and 62 are LPFs, 71 and 72 are A / D converters for converting the input from analog to digital, 81
84 to 84 are correlation detectors for despreading, 91 and 92 are squarers for squaring the input signal, 100 is an AFC circuit, 110 is a data decoding circuit, 151 is an adder for adding the outputs of the correlators 81 and 84, 152 is an adder that adds the output of the correlator 82 and the negative output of the correlator 84; 120 is an adder that adds the outputs of both the squarers 91 and 92; 130 is a synchronization acquisition determination circuit; The code generation circuit 200 is a code clock recovery circuit.

In the figure, QPSK modulation is performed and Ich
A spread code sequence C _I is used for data, and a spread code sequence C _Q is used for Qch data. The quadrature modulated spread spectrum signal received at 10 is a BPF 20 and an AGC
The signal is sent to mixers 41 and 42 for frequency conversion to a baseband band through a circuit 30. Here, the signals are generated by the local signal source 51 and are orthogonally separated by 52 to be 41 and 42, respectively.
The received signal is down-converted into a baseband separated into Ich and Qch according to the carrier frequency input to the mixer.

The received signals converted to the baseband are passed through the LPFs of the respective channels, and then A / D converters 71 and 72.
A / D-converted at the spreading code rate by LP at the same time
The signal after passing through F is sent to the code clock recovery circuit, and the spread code clock is recovered.

After the A / D conversion, for each of the Ich and Qch signals, a despreading correlator correlates the data for each data symbol section with the spread code sequences C _I and C _Q generated by the spread code generation circuit 140. Perform detection. That is, the despreading correlation detector 81 correlates the Ich signal and the spread code sequence C _I represented by (Equation 13), 82 the correlation between the Ich signal and C _Q represented by the equation (14), 83 Detects the correlation between the Qch signal represented by (Equation 15) and C _I, and 84 detects the correlation between the Qch signal represented by (Equation 16) and C _Q. The synchronous acquisition detection uses the value obtained by squaring the correlation values detected by the correlators 81 and 83 by the squarers 91 and 92 and adding them by the adder 120 according to (Equation 17). The synchronization acquisition determination circuit 130 determines whether or not synchronization has been acquired from the output value of the adder 120, and controls the generated code pattern of the spreading code generation circuit 140 to perform initial synchronization acquisition.

Next, when synchronization acquisition of the spread code sequence is established, the AFC circuit 100 starts a process of correcting a frequency deviation.
In this embodiment, it is assumed that the frequency deviation is obtained according to (Equation 22). The output value of the adder 151 obtained by adding the correlation output of the correlator 81 and the correlation output of the correlator 84, and the output value of the adder 152 obtained by adding the inverted value of the correlation output of the correlator 82 and the correlation output of the correlator 84. The AFC circuit 100 calculates the frequency deviation Δω by using the obtained value, and sends correction value information to the data decoding circuit 110. In the data decoding circuit 110, all the correlators 81 to 8
4, and decodes the data based on the correction value information from the AFC circuit 100.

As described above, in the present embodiment, I after quadrature detection is used.
A despreading correlator is provided for each of the spreading codes C _I and C _Q for each of the signals of channel ch and channel _Q , and the output value of
By performing the synchronization acquisition determination using the sum of squares, when the phase per one cycle of the spreading sequence due to the transmission / reception frequency deviation can be regarded as substantially constant, the influence of the frequency deviation can be eliminated, and the synchronization acquisition time at the time of the initial synchronization acquisition can be reduced. Can be shortened. Further, since the frequency deviation value is obtained using the output of each correlator, the frequency deviation can be corrected at the time of data decoding.

In this embodiment, the circuit configuration according to (Equation 22) is used to determine the frequency deviation value.
There is no problem with the circuit configuration according to 9). In this case, the adders 151 and 152 in FIG. 1 are eliminated. Further, in this embodiment, the combination of the outputs of the correlators 81 and 83 is used for the synchronization acquisition determination.
The same operation can be performed with a combination of the outputs. Further, in the present embodiment, four correlator outputs are used for data decoding, but a combination of two correlator outputs of correlators 81 and 84 or 82 and 83 can also be used.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of a synchronization acquisition and AFC circuit on the receiving side, which is a main part of a signal processing circuit according to a second embodiment of the present invention.

In FIG. 2, reference numeral 10 denotes a radio antenna;
Is a BPF, 30 is an AGC circuit, 41 and 42 are I
ch and Qch down mixers, 51 is a local signal source, 52 is a π / 2 phase separator, 61 and 62 are LPFs, 7
1, 72 are A / D converters, 91, 92 are squarers, 1
Reference numeral 00 denotes an AFC circuit, 110 denotes a data decoding circuit, 120 denotes an adder, 130 denotes a synchronization acquisition determination circuit, 140 denotes a spreading code generation circuit, and 200 denotes a code clock recovery circuit. The above is the same as the configuration in FIG. . The difference from the configuration of FIG. 1 is that the despreading correlation detectors 81 to 84 have Qch
C _I against the signal only obtains the correlation between each of the spreading code sequence C _Q, signals of Ich is the circuit configuration for obtaining a correlation between C _I, correlators 82 and adder 15 for despreading
1 and 152 are removed.

In this embodiment, the operation of the synchronization acquisition determination is basically the same as that of the first embodiment. However, the method of deriving the frequency deviation value after the establishment of the synchronization acquisition is expressed by (Equation 19), and the correlation in the AFC circuit is determined. Δω is obtained from the output values of the correlator 81 and the correlator 83 and sent to the data decoding circuit 110 as correction value information. In the data decoding circuit, the output values of the correlators 81 and 84 and A
Data is decoded based on the correction value information from the FC circuit 110.

As described above, for only one of the signals after quadrature detection, the correlation with the respective spreading code sequences of C _I and C _Q is obtained, and the synchronization acquisition and the frequency deviation Δ
By obtaining ω, the same effect as that of the first embodiment of eliminating the influence of the frequency deviation can be obtained, and the circuit configuration can be simplified.

In this embodiment, the correlation between the Qch signal and the respective spread code sequences of C _I and C _Q is obtained. However, the spread of the C _I and C _Q signals of the Ich signal is obtained. the correlation between the code sequence signal Qch course also be possible as a circuit configuration for obtaining a correlation between C _Q.

As described above, in the first and second embodiments, an active correlator is assumed as a despreading correlation detector as can be seen from the use of a spreading code generation circuit. There is no problem even if other correlators are used. Further, in this embodiment, the signal processing is performed using the A / D conversion rate as the spread code rate. However, the same processing can be performed by performing A / D conversion at a rate higher than the spread code rate.

In this embodiment, the AFC correction is performed at the time of data decoding by asynchronous quadrature detection. However, since the frequency deviation Δω is obtained, the AFC can be performed by the carrier recovery method in the absolute synchronous detection circuit. it can.

[0071]

As described above, the effects of the present invention are as follows. The QPSK modulated wave using different spreading code sequences is separated from the carrier band into Ich and Qch of the baseband band on the receiving side, and each signal is separated. Correlation detection is performed for each of C _I and C _Q , and the use of the sum of squares of the correlation output makes it possible to determine synchronization acquisition without being affected by frequency deviation, thereby shortening the synchronization acquisition time.

Further, by calculating the frequency deviation amount using the output value of the correlation detector in the AFC circuit, it is possible to correct the frequency deviation in any of the delay detection method and the synchronous detection method.

[Brief description of the drawings]

FIG. 1 is a block diagram of a main part of a signal processing circuit according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a main part of a signal processing circuit according to a second embodiment of the present invention;

FIG. 3 is a block connection diagram of a conventional BPSK-type synchronization acquisition circuit.

[Explanation of symbols]

 Reference Signs List 10 wireless antenna 20 BPF 30 AGC circuit 41, 42 down mixer 51 local signal source 52 π / 2 phase separator 61, 62 LPF 71, 72 A / D converter 81-84 despreading correlation detector 91, 92 2 Device 100 AFC circuit 110 QPSK modulation data decoding circuit 120, 151, 152 Adder 130 Synchronization acquisition judgment circuit 140 Spread code generation circuit 200 Code clock reproduction circuit

Claims (10)

(57) [Claims] 1. A quadrature spread modulated wave in which an information signal is directly spread on a transmitting side by using different spreading code sequences for an in-phase component and a quadrature component, and a base in which the in-phase component and the quadrature component are separated from a received carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A third and fourth despreading correlation detectors for the in-phase component and the quadrature-component baseband signal with a quadrature-component spreading code sequence, and the four despreading correlators, respectively. A decoding circuit for decoding data from a plurality of outputs, a first multiplier for squaring the output of the first despreading correlation detector, and squaring the output of the second despreading correlation detector A second multiplier; and the first,
A first adder for adding a second multiplier output;
A determination circuit for performing synchronization acquisition determination in accordance with the output level of the adder, and a first and second despreading correlation detector output, or a third and fourth despreading correlation detector output, or A second adder for adding a first despreading correlation detector output and a fourth despreading correlation detector output; and a second despreading correlation detector output and a third despreading. A subtractor for subtracting the output from the correlation detector for use, and a correction circuit for obtaining a frequency deviation based on a combination of any one of the outputs of the second adder and the subtractor and performing correction at the time of data decoding. Signal processing circuit. 2. A quadrature spread modulated wave in which an information signal is directly spread on a transmitting side by using spreading code sequences different from each other for an in-phase component and a quadrature component, and a base separated from an in-phase component and a quadrature component from a reception carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A third and fourth despreading correlation detectors for the in-phase component and the quadrature-component baseband signal with a quadrature-component spreading code sequence, and the four despreading correlators, respectively. A decoding circuit for decoding data from a plurality of outputs, a first multiplier for squaring the output of the third despreading correlation detector, and squaring the output of the fourth despreading correlation detector A second multiplier; and the first,
A first adder for adding a second multiplier output;
A determination circuit for performing synchronization acquisition determination in accordance with the output level of the adder, and a first and second despreading correlation detector output, or a third and fourth despreading correlation detector output, or A second adder for adding a first despreading correlation detector output and a fourth despreading correlation detector output; and a second despreading correlation detector output and a third despreading. A subtractor for subtracting the output from the correlation detector for use, and a correction circuit for obtaining a frequency deviation based on a combination of any one of the outputs of the second adder and the subtractor and performing correction at the time of data decoding. Signal processing circuit. 3. A quadrature spread modulated wave in which an information signal is directly spread on a transmitting side by using spreading code sequences different from each other for an in-phase component and a quadrature component, and a base having the in-phase component and the quadrature component separated from a receiving carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A third and fourth despreading correlation detectors for the in-phase component and the quadrature-component baseband signal with a quadrature-component spreading code sequence, and the four despreading correlators, respectively. A decoding circuit for decoding data from a plurality of outputs, a first multiplier for squaring the output of the first despreading correlation detector, and squaring the output of the second despreading correlation detector A second multiplier; and the first,
A first adder that adds the output of the second multiplier, a determination circuit that performs synchronization acquisition determination according to the output level of the adder,
A first and second despreading correlation detector output, or a third and fourth despreading correlation detector output, or a first despreading correlation detector output, and a fourth despreading detector A second adder for adding a correlation detector output, a subtractor for subtracting the second despreading correlation detector output and a third despreading correlation detector output, and the second addition A signal processing circuit comprising: an automatic frequency control circuit that determines a frequency deviation based on a combination of any one of outputs of a subtractor and a subtractor and corrects a local signal in the frequency conversion circuit. 4. A quadrature spread modulated wave in which an in-phase component and a quadrature component are directly spread on an information signal using different spreading code sequences on a transmission side, and a base in which the in-phase component and the quadrature component are separated from a reception carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A third and fourth despreading correlation detectors for the in-phase component and the quadrature-component baseband signal with a quadrature-component spreading code sequence, and the four despreading correlators, respectively. A decoding circuit for decoding data from a plurality of outputs, a first multiplier for squaring the output of the third despreading correlation detector, and squaring the output of the fourth despreading correlation detector Adding a second multiplier and the outputs of the two multipliers A first adder, a determination circuit for performing synchronization acquisition determination according to the output level of the first adder, the first and second despreading correlation detector outputs, or the third and third A second adder for adding the output of the fourth correlation detector for despreading, or the output of the first correlation detector for despreading, and the output of the fourth correlation detector for despreading; A subtractor for subtracting the output of the correlation detector for spreading and the output of the third correlation detector for despreading; and a frequency deviation obtained by combining any one of the outputs of the second adder and the subtractor. A signal processing circuit comprising: an automatic frequency control circuit that corrects a local signal in the conversion circuit. 5. A quadrature spread modulated wave in which an information signal is directly spread on a transmitting side by using spreading code sequences different from each other for an in-phase component and a quadrature component, and a base having the in-phase component and the quadrature component separated from a reception carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A third despreading correlation detector for the orthogonal component baseband signal and the orthogonal component spreading code sequence, and a decoding circuit for decoding data from the outputs of the first and third despreading correlators. A first multiplier for squaring the output of the first despreading correlation detector, a second multiplier for squaring the output of the second despreading correlation detector,
A signal processing circuit comprising: an adder that adds the first and second multiplier outputs; and a determination circuit that performs synchronization acquisition determination according to an output level of the adder. 6. A quadrature spread modulated wave in which an information signal is directly spread on a transmitting side by using different spreading code sequences for an in-phase component and a quadrature component, and a base in which the in-phase component and the quadrature component are separated from a received carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. A frequency deviation is obtained from the outputs of the third despreading correlation detector of the orthogonal component baseband signal and the orthogonal component spreading code sequence, and the first and second despreading correlation detectors. 6. The signal processing circuit according to claim 5, further comprising a circuit for performing correction at the time of decoding. 7. A quadrature spread modulated wave in which an in-phase component and a quadrature component are directly spread on an information signal by using different spreading code sequences on a transmitting side, and a base in which the in-phase component and the quadrature component are separated from a reception carrier band. A frequency conversion circuit for converting into a band-band signal, and first and second despreading correlation detectors for the in-phase component spread code sequence with respect to both the in-phase component and the quadrature component baseband signal, respectively. Calculating a frequency deviation from outputs of a third despreading correlation detector of the orthogonal component baseband signal and the orthogonal component spreading code sequence, and the first and second despreading correlation detectors. 6. The signal processing circuit according to claim 5, further comprising an automatic frequency control circuit for correcting a local signal in the frequency conversion circuit. 8. A quadrature spread modulated wave in which an in-phase component and a quadrature component are directly spread by using a spreading code sequence different from each other on a transmitting side, to obtain a base signal obtained by separating an in-phase component and a quadrature component from a reception carrier band. A frequency conversion circuit that converts the signal into a band signal, and a baseband signal of the in-phase component,
A first despreading correlation detector for the in-phase component spreading code sequence, and a second and a quadrature component spreading code sequence for both the in-phase component and the quadrature component baseband signal.
A third despreading correlation detector, a decoding circuit for decoding data from the outputs of the first and third despreading correlators,
A first multiplier for squaring the output of the inverse spread correlation detector, a second multiplier for squaring the output of the third inverse spread correlation detector, and the first and second multiplications A signal processing circuit comprising: an adder that adds the outputs of the adders; and a determination circuit that performs synchronization acquisition determination according to the output level of the adder. 9. A quadrature spread modulated wave in which an in-phase component and a quadrature component are directly spread by using a spreading code sequence different from each other on the transmitting side to obtain a base having the in-phase component and the quadrature component separated from a reception carrier band. A frequency conversion circuit that converts the signal into a band signal, and a baseband signal of the in-phase component,
A first despreading correlation detector for the in-phase component spreading code sequence, and a second and a quadrature component spreading code sequence for both the in-phase component and the quadrature component baseband signal.
9. The signal processing according to claim 8, further comprising a third despreading correlation detector, and a correction circuit for obtaining a frequency deviation from outputs of the second and third despreading correlation detectors and performing correction at the time of data decoding. circuit. 10. A quadrature spread modulated wave in which an in-phase component and a quadrature component are directly spread using an spreading code sequence different from each other on a transmitting side, to obtain a base signal obtained by separating an in-phase component and a quadrature component from a reception carrier band. A frequency conversion circuit for converting the signal into a band signal, a first despreading correlation detector for a spread code sequence of the in-phase component for the baseband signal of the in-phase component, and a base for the in-phase component and the quadrature component. For both band signals, the second and third despreading correlation detectors with the orthogonal component spreading code sequence, and the frequency deviation from the outputs of the second and third despreading correlation detectors, respectively. 9. The signal processing circuit according to claim 8, further comprising an automatic frequency control circuit for determining a local signal in the frequency conversion circuit.