JP2000299649A - Device and method for acquiring synchronization - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability by plurally varying the generated phase of a diffusion code system on a receiving side, concerning the diffusion code system being the same diffusion code system as a diffusion code system used for diffusion on a transmitting side, to obtain a correlation value so as to improve a synchronization acquiring ratio. SOLUTION: Since a phase stored in a correlating phase storing part 1 is random in a relation with the address number of a RAM 1, a correlating part 2 executes the correlating arithmetic of one correlating interval by the same probability. When the same phases exist in a phase stored in the RAM 1 by at least three, a correlating interval is executed once in probability. A write position deciding part 5 excludes the correlating interval and only correlating data obtained from the correlating section is stored in a synchronizing position candidate storing part 6. At the time of receiving a correlation set finishing signal S6 from a counter part 3, a synchronization deciding part 7 output the portion of the number of passes set as a synchronizing position signal S15 which is not the same pass from the correlating data. The generating phase of the same diffusion code system as that used on a transmitting side is plurally varied on a receiving side to obtain a correlating value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization acquisition apparatus and method, and is applied to, for example, a case where code synchronization is established in a demodulation unit of a receiving apparatus of a mobile communication system employing CDMA (code division multiple access). Can be done.

[0002]

2. Description of the Related Art A CDMA receiving apparatus generates a spreading code which is the same as a spreading code of a transmitting apparatus, and performs despreading using this spreading code.

However, since the phase of the code sequence included in the received signal received by the receiving device and the phase of the spread code sequence generated at the receiver usually do not match, it is necessary to perform an operation for matching these. Required.

[0004] An operation for matching these and establishing code synchronization is synchronization acquisition.

As a specific method of the conventional synchronous acquisition, for example, there is a method described in the following document.

Literature 1: "Digital mobile communication technology" (Japan Industrial Technology Center, p. 126) In the sliding correlation method disclosed in Literature 1, the phase of the PN code generated on the receiving side is shifted while the phase on the transmitting side is shifted. And the point on the receiving side where the phases match are sequentially searched.

[0007]

A more specific description will be given on the basis of the principle of the method described in Document 1 in consideration of an actual circuit. First, on the transmitting side, continuous fixed data (for example, all 1's) Code sequence) with a predetermined PN
The signal is spread by a code and transmitted wirelessly to the propagation path.

[0008] Although the transmission side data SD shown in FIG. 3A is continuous fixed data of all ones, change data "-1" is inserted in the third bit from the left end. A spreading code (for example, P
N code) In order to identify each code of SC, as shown in FIG.
The numbers from number 8 to number 8, that is, 0, 1,...

Next, this signal that has passed through the radio propagation path is:
The data is received by the receiving device as receiving data AD as shown in FIG.

The state shown in FIG. 3C is a case where the spreading code generated for despreading the receiving side data AD in the receiving side device is the spreading code SC0 of phase 0.

The receiving apparatus that has received the receiving data AD first generates a spreading code SC0 shown in FIG. 3C so that a correlation operation can be performed using the spreading code of phase 0.

The correlation power (correlation value) obtained as a result of the correlation operation is considered to indicate a higher value as the two phases are better matched. The correlation power is compared with the correlation power. If the correlation power is large, the phase 0 is stored as a candidate for a synchronous position.

In the state shown in FIG. 3 (C), the spreading codes SC0 and SDC are not synchronized (matched) in any correlation section, so that the obtained correlation powers are all less than the threshold value.

[0014] Therefore, in the receiving side device, the phase of the spreading code is shifted by 1 (that is, one chip) thereafter.
The correlation calculation between the reception side data (received signal) and the spread code is performed again using the spread code of (1), the correlation power and the threshold value are compared in the same manner as described above, and stored as a synchronous position candidate or discarded as an asynchronous position. Or choose.

Thereafter, the same operation is performed on all the phase candidate spaces using the spreading code of each phase while sequentially changing the phase of the spreading code by one.

The phase 1 spreading code is, for example, as shown in FIG.
This is the spreading code SC1 of (D).

Similarly, the spread code SC2 of phase 2 is shown in FIG. 3E, and the spread code SC3 of phase 3 is shown in FIG.

In the example shown in FIG. 3, since the SDC shown in FIG. 3B and the spread code SC2 shown in FIG. 3E match, a peak value of the correlation power is obtained by the correlation calculation of this part.

In the final determination of the correlation position, for example, the synchronization position corresponding to the highest correlation power is determined as the synchronization position to be obtained from the remaining synchronization position candidates, and the result is output.

However, the peak value of the correlation power obtained by the correlation calculation of the phase 2 is 2, 3, 4 of SC2 in FIG.
Is located in the section 1 of the reception side data AD and high correlation power is obtained. However, since the other sections include the section -1 of the reception side data AD, the value is sufficient. Is not high.

This causes a decrease in the synchronization acquisition rate.

FIG. 2 shows an example of a system in which change data that is not continuously fixed is inserted in a part of the continuous fixed data. An example of such a system is "CDMA2000" proposed in the United States.

In FIG. 2, a pilot signal section PI1
And PI2 are continuous fixed data corresponding to 1 of the transmission data indicated by SD in FIG. 3A, and transmission power bit sections TC1 and TC2 correspond to-of transmission data indicated by SD in FIG. This is change data corresponding to 1. The change data can take 1 or -1.

When the correlation operation is performed in the section of CC1, the transmission signal is D × PN because the fixed data D is spread by a predetermined spreading code PN and transmitted. If the effects of the propagation path and the interference are not considered for simplicity, the transmission signal D × PN becomes the reception signal on the reception side as it is.

The reception side despreads the received signal D × PN with a predetermined spreading code used on the transmission side. If the codes are synchronized, the normalized despread correlation value becomes D,
In FIG. 2, the correlation value 1 is obtained because the continuous fixed data is 1.

However, in a real environment, in order to reduce the influence of interference, conventional continuous fixed data is always transmitted (or transmitted for a sufficiently long time to be regarded as being constantly transmitted). When the correlation operation per phase is performed for a long period to secure the processing gain, the possibility that the correlation operation includes change data as in CC3 becomes high, and even if the codes are synchronized, the correlation value becomes 1
As a result, the processing gain corresponding to the length of the correlation operation section cannot be obtained, and the synchronization acquisition rate decreases.

[0027] In view of the above, in the above-described system in which the change data is inserted in a part of the continuous fixed data, there is a demand for the realization of a synchronization acquisition circuit that can obtain sufficient characteristics.

When the continuous fixed data is a pilot signal, the continuous fixed data can be regarded as known data in the sense that the system can recognize in advance that the value is all ones. The change data changes every moment according to the situation, and can be regarded as unknown data in the sense that the system cannot recognize it in advance.

[0029]

According to a first aspect of the present invention, a correlation between a spread code sequence generated on the receiving side and a received signal is executed while shifting the phase relationship between the received signal and the correlation value. In the synchronization acquisition device that establishes code synchronization based on the correlation value, for the spreading code sequence that is the same spreading code sequence as the spreading code sequence used for spreading on the transmitting side, the generation phase on the receiving side is plural. It is characterized by comprising correlation information forming means for changing the number of times to obtain the correlation value.

According to the second aspect of the present invention, a correlation value is obtained by performing a correlation operation on the spread code sequence generated on the receiving side while shifting the phase relationship between the received signal and a code synchronization based on the correlation value. In the synchronization acquisition method for establishing the correlation information, the spread code sequence, which is the same as the spread code sequence used for spreading on the transmission side, is formed on the reception side by changing the generation phase thereof a plurality of times to obtain the correlation information. Processing is performed.

Further, in the third invention, a variable data section and a fixed data section are arranged in a predetermined pattern on a transmission-side spread code sequence used for spreading on the transmission side, and the predetermined pattern is recognized. On the receiving side, while changing the phase relationship between the receiving-side spread code sequence and the received signal, which are the same code sequence as the transmitting-side spread code sequence, these correlation operations are performed to obtain a correlation value, and the correlation value is calculated. A synchronization acquisition device for establishing code synchronization based on: (1) a spread code sequence generating means for generating the receiving spread code sequence in accordance with the change of the phase relationship; Correlation calculation means for performing a correlation calculation with a received signal for each predetermined correlation calculation section; and (3) performing a correlation calculation at each time point in the change data section in response to the change of the phase relationship and a predetermined pattern. (4) identifying and processing the correlation calculation of the fixed data section and the correlation calculation of the changing data section in accordance with the determination; A correlation processing means for preventing such cancellation.

Further, in the fourth invention, a variable data section and a fixed data section are arranged in a predetermined pattern on a transmission-side spread code sequence used for spreading on the transmission side, and the predetermined pattern is recognized. On the receiving side, a correlation value is obtained by performing a correlation operation on these signals while changing the phase relationship between the reception-side spread code sequence and the reception signal, which are the same code sequence as the transmission-side spread code sequence. (1) generating the receiving-side spread code sequence according to a change in the phase relationship;
(2) performing a correlation operation between the reception-side spread code sequence and the reception signal for each predetermined correlation operation section; and (3) performing a correlation at each time point in accordance with the change in the phase relationship and a predetermined pattern. It is determined whether the calculation corresponds to the changed data section or the fixed data section. (4) According to the determination, the correlation calculation of the fixed data section and the correlation calculation of the changed data section are identified and processed. By doing so, offsetting of these is prevented.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) Embodiment A synchronization acquisition device and method according to the present invention are applied to a synchronization acquisition circuit of a reception device of a mobile communication terminal in a CDMA mobile communication system. First to third embodiments will be described.

[0034] One transmitting apparatus (base station) constituting the mobile communication system inserts changed data into a part of continuous fixed data and transmits the data spread with a predetermined spreading code onto a transmission path. It is assumed that

As this spreading code, for example, a PN code can be used, the continuous fixed data can be, for example, an all-one pilot signal, and the changed data is, for example, a transmission transmitted from a base station for so-called closed loop control. Information for power control may be used.

(A-1) Configuration of First Embodiment and Operation of Each Unit FIG. 1 shows a synchronization acquisition circuit 10 of this embodiment. The synchronization acquisition circuit 10 is assumed to be mounted on a mobile communication terminal having a digital rake receiver capable of separating multipaths in units of a chip or N times as accurate as a chip.

In FIG. 1, the main functional blocks of the synchronization acquisition circuit 10 include a correlation phase storage unit 1, a correlation unit 2, a counter unit 3, and a synchronization position candidate selection unit which are mutually connected by a bus. 4, a write position determining unit 5, a synchronous position candidate storage unit 6, and a synchronous position determining unit 7.

The correlator 2 multiplies the signal received by the antenna by a carrier and converts the received signal AS frequency-converted to the baseband band with a spread code generated at a variable phase in the correlator 2. It is a correlation calculator that performs a correlation calculation.

The correlation power S obtained as a result of the correlation operation
4 is output from the correlation section 2 together with the corresponding correlation position S3. Then, one set of correlation power and a correlation position constitute one piece of correlation data.

The correlation section 2 also outputs a correlation end signal S5 for notifying the end timing of one correlation operation. The correlation end signal S5 is connected to the counter 3 and the synchronization position candidate selector 4.

The correlation phase storage unit 1 is a storage device for storing the phase of the spread code generated by the correlation unit 2, and can be constituted by, for example, a RAM (random access memory).

For example, the RAM 1 stores the phase of the spreading code generated in the correlator 2 (the meaning of the phase is the same as that described above), and the RAM 1 stores the phase according to the timing at which the phase is read from the RAM 1. And the correlator 2
Generates the spreading code of the corresponding phase.

The correlation phase storage unit 1 is set in advance by a processing system (not shown) such as a CPU. In this setting, the phase is determined by the R
AM1 is stored, for example, from a lower address to an upper address.

The counter section 3 is a counter that counts up the count signal S1 when the correlation end signal S5 is input from the correlation section 2 and outputs the count signal S1 to the correlation phase storage section 1. The count signal S1 is used for addressing the correlation position storage unit 1, and the RAM address specified is incremented each time the count-up is performed, so that the phase of the spread code changes. In this embodiment,
The increment is performed at regular time intervals.

The counter unit 3 is reset by the synchronization acquisition start signal S16 supplied by the CPU, and is ready to start counting up.
Further, the CPU presets the number V1 of all correlation phase candidates corresponding to the upper limit of the count-up.

When the count value exceeds the number of all correlation phase candidates V1, the counter section 3 outputs a correlation set end signal S6 to the subsequent-stage synchronous position determination section 7 indicating that the processing of all the phase candidates has been completed. .

The correlation set end signal S6 is stored in the RAM 1
Is a signal indicating that the correlation calculation of all the phases stored in is completed.

The synchronization position candidate selection unit 4 is a kind of comparator.
This circuit determines whether the correlation power of certain correlation data is a peak value (corresponding to a synchronous position), that is, whether the phase is a synchronous position or an asynchronous position.

The correlation power generally indicates a peak value when the phase of the received signal AS and the phase of the spread code sequence generated on the receiving side are synchronized (that is, when the phase difference between them is 0). When not synchronized, it is expected to be less than the threshold Th.

The magnitude of the correlation power peak value is generally large, for example, in the pilot signal section that is all 1, and becomes small when the section other than the pilot signal section that is change data is included.

Since the correlation power of most of the correlation data corresponds to the asynchronous position and is less than the threshold value Th,
Usually, the synchronization position candidate selection unit 4 eliminates the noise as noise.

The threshold value Th is set according to the C
Performed by the PU in advance.

If the correlation power is equal to or greater than the threshold value Th, the write position determination unit 5 performs processing to determine whether or not it is a synchronization position candidate.

When the correlation power is equal to or larger than the threshold Th, the synchronous position candidate selecting section 4 sends out a write instruction signal S8, and upon receiving this signal S8, the write position determining section 5
The correlation data (S) separately supplied from the correlation unit 2
(3, S4).

The write position determining unit 5 is a circuit that receives the correlation data (that is, the correlation position S3 and the correlation power S4) directly from the correlation unit 2 and writes the correlation data to the corresponding address of the synchronous position candidate storage unit 6.

The write position is the RAM address of the synchronous position candidate storage (RAM) 6 (designated by address S9).
Therefore, the writing position determination unit 5 performs processing so that correlation data having the same phase is not stored in the synchronization position candidate storage unit 6 in an overlapping manner.

In this processing in the write position determining unit 5, first, it is checked whether or not correlation data having the same phase as the correlation data has already been stored in the synchronization position candidate storage unit 6.

If the correlation data is stored, the correlation power is compared between the correlation data having the same phase (ie, between the correlation data and the correlation data already stored having the same phase), and the correlation power is newly obtained. If the correlation power of the correlation data is large, the correlation power (correlation data) is replaced. If the correlation power is small, the newly obtained correlation data is discarded.

On the other hand, if the phase to be written is not stored in the synchronization position candidate storage section 6, the phase is compared with the minimum correlation power S7 (of a plurality of correlation data) stored in the synchronization position candidate storage section 6. If it is larger, the correlation data corresponding to the minimum correlation power is replaced with the newly obtained correlation data.

As a result, it is possible to eliminate low-reliability synchronization position candidates which are highly likely to be affected by the change data. Further, the memory capacity of the synchronization position candidate storage unit 6 can be reduced, and the use efficiency can be improved.

As described above, the synchronization position candidate storage section 6 is a RAM for storing synchronization position candidates. For example, it is assumed that one set of correlation data is stored in one RAM address.

The synchronization position candidate storage section 6 stores the phase S10 and the correlation power S11 (correlation data) stored according to the address signal S9 input from the write position determination section 5.
Or accumulates the phase S10 and the correlation power S11.

The synchronization position candidate storage section 6 can rearrange and rearrange the stored correlation data (phase and correlation power) of each set in the order of the correlation power.

The synchronous position determining unit 7, which is another device for reading from the synchronous position candidate storage unit 6,
Can address the RAM 6 at the address S12 and read out the correlation data (phase S13 and correlation power S14) stored at the address.

The phase S13 of the correlation data read by the synchronous position determining unit 7 corresponds to the final synchronous position signal S15 output by the synchronous position determining unit 7, and the phase S13 is read by the counter unit 3 from the correlation set. This is performed by supplying the end signal S6.

When the correlation set end signal S6 of all the phase candidates is input to the synchronization position determination unit 7, the synchronization position candidate storage unit 6
Reads the correlation data (phase S13 and correlation power S14) in descending order of correlation power according to the address S12. Among the read phases, the phases that are not the same path are output as the synchronization position signal S15 for the preset number of passes.

The predetermined number of paths is a concept of the structure of the rake receiver. If the rake receiver has two demodulated parts (two fingers), the synchronous position signal S15 is Two are output, one for each finger.

Hereinafter, the operation of the present embodiment having the above configuration will be described.

(A-2) Overall Operation of the First Embodiment Before starting the synchronization acquisition processing, the CPU determines the phase for performing the correlation operation from the lower address to the upper address in the order of operation. It is stored in the phase storage unit 1.
In all, the phases of the total number of phase candidates V1 are stored.

When this phase designates, for example, phase 1, a spread code sequence of phase 1 is generated.

Accordingly, the correlation section 2 having received the phase performs a correlation operation between the spread code sequence of the phase and the received signal AS to obtain the correlation data S3 and S4.

The interval at which each phase is read from the correlated phase storage unit 1 corresponds to the speed at which the counter unit 3 counts up. When the count up of the counter unit 3 is determined, the phase is output from the correlated phase storage unit 1. Then, the correlation unit 2
Starts the correlation operation.

Further, since the relationship between the phase stored in each address of the correlation phase storage unit 1 and the corresponding address number is random, the received signal A
The relationship (phase difference) between the phase of S and the phase of the spreading code generated by the correlation unit 2 is also random.

Therefore, by storing the same phase in a plurality of addresses of the correlation phase storage unit 1, the spread code sequence of the same phase is received a plurality of times by the reception signal AS when viewed from the correlation unit 2.
Can be correlated.

In this embodiment, the length of one correlation section PL (see FIG. 3) is fixed. This may be, for example, about 100 chips, but as in CC3 in FIG.
If the length is 1 + TC1 or more, the change data is always included in any one of the correlation sections PL. Therefore, for example, it is desirable that the length be PI1 or less as in CC1 and CC2 in FIG.

When the synchronization acquisition start signal S 16 is input from the CPU to the counter section 3, the counter section 3 outputs a counter signal S 1 to the correlation position storage section 1.

The correlation phase storage unit 1 addressed by the count value indicated by the counter signal S1 outputs the phase S2 stored at the corresponding address.

For example, if the spreading code sequence of phase 0 is
In the case of SC0 in (C), if the phase S2 is 2, the correlation unit 2 generates the spread code sequence SC2 in FIG.

The address designation by the counter signal S1 is as follows.
In accordance with the count-up of the counter section 3, the processing is sequentially performed, for example, from the lower address to the upper address.

Since the relationship between the phase stored in the correlation phase storage unit 1 and the corresponding address number in the RAM 1 is random, in the correlation unit 2, each correlation section PL shown in FIG. Sections (2,3,4), (5,
6, 7,) and (8, 0, 1) are calculated with the same probability.

The correlation power generally shows a peak value when the phase of the spread code sequence generated on the receiving side is synchronized with the received signal AS (as in FIG. 3E).

However, even if the phase of the received signal AS and the phase of the spread code sequence are synchronized, FIG.
The correlation power obtained from one correlation section PL has a magnitude relation.

The magnitude relation of one correlation section PL is (2, 3,
4) is the largest, and (5, 6, 7) and (8, 0, 1) have the same correlation power. Because the correlation interval (2,3,
The data AD of (4) is all 1, whereas (5, 6,
This is because 1 and -1 are mixed in (7) and (8, 0, 1). Despite different data AD (5, 6,
7) and (8, 0, 1) have the same correlation power because the correlation value of the correlation section (5, 6, 7) is-／ and the correlation value of the correlation section (8, 0, 1) is 1 This is because the correlation power is 1/9, which is the same as the correlation power.

Therefore, if there are three or more identical phases among the phases stored in the RAM 1, the correlation section (2, 3, 4) is performed stochastically once.

The correlation power S4 thus obtained is
Most of the correlation data is excluded by being input to the synchronization position candidate selection unit 4 and being compared with a threshold value Th preset from the CPU.

Further, the above-mentioned correlation sections (5, 6, 7) and (8, 0, 1) are excluded by the write position determination section 5, and only the correlation data obtained from the correlation section (2, 3, 4) is synchronized. It is stored in the position candidate storage unit 6. Thus, the capacity of the RAM of the synchronization position candidate storage unit 6 can be reduced.

Further, a spread code sequence having the same phase is transmitted a plurality of times.
As described in the section of the problem to be solved by the present invention, the correlation operation with the received signal AS is performed in the same manner as in the conventional method in which the correlation operation is performed over a long period to increase the processing gain. It is possible to reduce the erroneous determination of the synchronization position candidate due to the decrease of the correlation power due to the above.

Correlation set end signal S from counter section 3
When receiving the synchronization position signal S15, the synchronization position determination unit 7 determines, from the correlation data stored in the synchronization position candidate storage unit 6 obtained in the above procedure, the number of paths previously set as the synchronization position signal S15 that is not the same path. Output minutes.

In this example, for simplicity, the spreading factor is 3, and the code length of one cycle of the spreading code SDC is 9 (0 to 8).
In the actual case, the spreading factor is, for example, 5
The code length for one cycle of SDC is, for example, about 3
It is about ten thousand.

(A-3) Effects of the First Embodiment As described above, according to the present embodiment, the phase for performing the correlation operation between the received signal and the predetermined spreading code is randomly changed, and the same phase is calculated. Performs multiple operations on
Since the same phase is not stored in the synchronization position candidate storage unit, the probability that the obtained correlation power of the synchronization position candidate is affected by the change data can be reduced.

Therefore, even with a signal in which the change data is inserted in a part of the continuous fixed data, it is possible to obtain a synchronization acquisition characteristic equivalent to that of a conventional system in which continuous fixed data is continuously transmitted. become.

The synchronous position candidate selector compares the correlation power obtained by the correlation operation with a predetermined threshold so as to prevent the asynchronous position from being stored as the synchronous position candidate. Only the position can be specified as the synchronization position, and the processing efficiency is high.

Furthermore, only the correlation data of the phase having the high correlation power is selected by the processing in the synchronization position candidate selection section 4 and only one correlation data of the same phase is selected. Thus, the use efficiency of the synchronization position candidate storage unit 6 due to performing the correlation calculation a plurality of times is prevented, and the memory capacity of the synchronization position candidate storage unit can be reduced and the usage efficiency can be increased.

In other words, in the selection process, the correlation data having the low reliability which includes the influence of the change data is excluded, and only the correlation data having no (or little) influence of the change data is selected. You can also catch that operation. Therefore, even when processing a signal in which change data is inserted into a part of a received signal, the present embodiment does not degrade the performance of synchronization acquisition.

The present embodiment is effective for preventing a situation in which a highly reliable correlation value cannot be obtained for a long period corresponding to at least a large number of frame periods.

(B) Second Embodiment In the first embodiment, when focusing on one correlation section having a synchronous position, it is determined whether the correlation power corresponding to the correlation section is sufficiently high or not. It depends on whether or not there is change data within, and in that sense was left to probability.

In other words, a sufficiently high correlation power was obtained only by the correlation calculation corresponding to the occurrence phase in which there was no change data in the correlation section among the occurrence phases changed plural times.

On the other hand, the present embodiment is characterized in that a sufficiently high correlation power can be obtained at any synchronous position without depending on whether or not there is change data in the correlation section.

(B-1) Configuration of the Second Embodiment FIG. 4 shows the configuration of the synchronization acquisition circuit 20 of this embodiment. The synchronization acquisition circuit 20 corresponds to the synchronization acquisition circuit 10 and is mounted on a mobile communication terminal having a digital rake receiver capable of separating multipaths in units of a chip or with N times the precision of a chip. It is assumed that

As shown in FIG. 6 (A), the reception signal RX1 received and processed by the synchronization acquisition circuit 20 has a change data section T1, T2 between the continuous fixed data sections P1, P2, P3 on the transmission side. After spreading and transmitting the inserted transmission data D with a spreading code of a predetermined cycle (cycle 16 in the illustrated example),
This is to be received by the receiving side via the propagation path.

In FIG. 6 (A), in order to identify each spreading code in one cycle, a spreading code number N1 of 0 to 15 is assigned to each spreading code. The arrangement pattern of the continuous fixed data and the change data in the transmission data D is uniquely specified by the spreading code number N1.

In the arrangement pattern, in the example shown in the figure, the transmission data D corresponding to the spreading codes of numbers 0 to 5 is continuous fixed data P1, and the transmission data D corresponding to the spreading codes of numbers 6 and 7 is change data T1. The transmission data P2 corresponding to the spreading codes of Nos. 8 to 13 and the Nos. 14 and 15
Is the transmission data T2, and the transmission data P3 corresponds to the spreading code of the next cycle number 0, 1, 2,....

As described above, each bit of the continuous fixed data is fixed to, for example, all "1", but the changed data is set to, for example, "1" or "-1" in accordance with the transmission power control or the like. Takes one of the following values.

In FIG. 4, the main functional blocks of the synchronization acquisition circuit 20 are composed of a spreading code generator 21, a product-sum operation unit 22, a data determination unit 23, which are connected to each other by a bus. An adder (A) 24 for data, an adder (B) 25 for change data, an adder / subtractor 26, a correlation power comparator 27, and a synchronous position determiner 28.

Among them, the spread code generator 21, the product-sum calculator 22, and the data determiner 23 constitute a correlation calculator 20A, which includes an adder 24, an adder 25, an adder / subtractor 26, and a correlation power comparator 27. Constitutes a correlation power calculator 20B. The correlation operation unit 20A can be regarded as corresponding to the correlation unit 2 in the first embodiment.

The above-mentioned received signal RX1 is supplied to an input terminal 2B connected to the product-sum operation unit 22 of the synchronization acquisition circuit 20.

The spread code generating section 21 receives the input from a well-known shift register for generating a spread code (for example, a PN code) PN1 with a generated phase corresponding to the correlation phase Φ1 supplied from the input terminal 2A, and a feedback tap. EX to get
A spreading code generator of a type incorporating an OR (exclusive OR) circuit or the like may be used.

The change of the correlation phase Φ1 can be made randomly (for example, so that the same occurrence phase appears a plurality of times within one period of the spread code) as in the first embodiment. In the embodiment, as described in the section of the problem to be solved by the invention, it is assumed that the value is sequentially changed by one.

Note that the correlation phase Φ1 is supplied from a processing system (not shown) such as a CPU.

[0110] Inside the spreading code generator 21,
A counter (not shown) for outputting the spreading code number N1 is provided. This counter has a correlation phase Φ1
, The spreading code numbers N1 of 0 to 15 are generated.

In the received signal RX1, the correlation phase Φ1 is, for example, the spreading code number N1 corresponding to the correlation section 1 at the generation phase 0 is 0, 1, 2,. The corresponding spreading code numbers N1 are 1, 2, 3,.
It becomes 6.

The count value N1 is cleared to 0 when it exceeds the maximum value of the spreading code number (15 in the illustrated example).

In short, the counter has the correlation phase Φ1
At the switching timing, a function of starting a new count-up from the count value corresponding to the correlation phase Φ1 is provided, so that the current spreading code number can be known from the count value.

A spreading code PN1 supplied from the spreading code generator 21 and shifted from the reference phase by a correlation phase Φ1;
The product-sum operation unit 22 that receives the above-described received signal RX1 supplied from the input terminal 2B is a circuit that performs a product-sum operation on these and outputs an operation result EC1.

The data judging unit 23 receiving the spreading code number N1 from the spreading code generating unit 21 calculates the product-sum operation result EC1 at that time based on the spreading code number N1.
This is a circuit for determining whether the data corresponds to a continuous fixed data section such as 1, P2, P3, or the like, or a changed data section such as T1, T2.

To make this determination, the data determination section 23
Recognizes the above arrangement pattern and outputs a determination signal J1 corresponding to the determination. In the present embodiment, when it is determined that the section is a continuous fixed data section, the determination signal J1 is “1”.
It shall be “0”.

This determination is correct in a synchronous state, but is inevitably incorrect in an asynchronous state.

According to the judgment signal J1, the calculation result E
C1 is taken into either the adder 24 or the adder 25, and is cumulatively added.

That is, the adder 24 is a circuit for performing cumulative addition for continuous fixed data, and accumulates the result EC1 when the judgment signal J1 is "1". The adder 25 is a circuit that performs cumulative addition for change data, and accumulates the result EC1 when the determination signal J1 is “0”.

The cumulative addition result (correlation value) of addition section 24 is represented by C
A1 and the cumulative addition result of the adding unit 25 is CB1.

The correlation values CA1 and CB1 obtained by cumulatively adding the result EC1 of the product-sum operation for one correlation section are:
Generally, it can take both positive and negative values.

If the section of the transmission data T1 has a length corresponding to one correlation section, for example, in the synchronous state, when the transmission data T1 is 1 (constant), the product-sum operation result EC1 for T1 is calculated. The cumulative addition result (that is, the correlation value) CB1 becomes “1”, and when T1 is −1 (constant), CB1 becomes “−1”.

The adder / subtracter 26 at the subsequent stage of the adders 24 and 25
Are the output CA1 of the adder 24 and the output CB1 of the adder 25.
And outputs an addition result C0 (= CA1 + CB1), and subtracts CB1 from CA1 to obtain a subtraction result C0.
1 (= CA1-CB1).

The correlation power comparing section 27 receiving the addition and subtraction results C0 and C1 calculates the correlation power by squaring each of C0 and C1, selects the larger one, and outputs it as the correlation power CP1. .

The synchronous position judging section 28 which receives the correlation power CP1 and the correlation phase Φ1 compares the correlation power CP1 with a predetermined threshold Th1, and determines that the CP1 is equal to the threshold T1.
When h1 is exceeded, the circuit holds a set of the correlation phase Φ1 and the correlation power CP1 at that time as correlation data (corresponding to the correlation data of the first embodiment).

When the correlation calculation for all the phase candidates is completed, the synchronization determination circuit 28 determines the synchronization position # 1 of the spread code from the held correlation information and sends it to the output terminal 2C. In this determination, the correlation phase having the largest correlation power CP1 is determined by the synchronization position Θ
It is good to be 1.

The synchronous position # 1 is output one by one for each finger as in the case of the first embodiment described above.

The threshold value Th1 is supplied from a processing system such as the CPU.

The operation of the second embodiment having the above configuration will be described below.

(B-2) Operation of the Second Embodiment When the synchronization acquisition processing is started, the processing system such as the CPU resets the cumulative addition value (correlation value) of the adder 24 and the adder 25. , The phase 0 (Φ1
= 0).

Receiving this, spread code generating section 21 generates spread code PN1 at phase 0. Phase 0 spreading code P
N1 is the spreading code PN1 of the reference phase. The product-sum operation using the spreading code PN1 of phase 0 corresponds to the correlation section 1 in FIG. Here, it is assumed that the length of one correlation section corresponds to six spread codes.

By multiplying a signal received from an antenna (not shown) by a carrier wave and converting the frequency of the received signal RX1 obtained by frequency conversion to the baseband band with the spreading code PN1 of the phase 0, a product sum operation is performed. The sum operation unit 22
Despreading is performed, and the calculation result EC1 is output.

At this time, in response to the spread code number N1 output from the counter in the spread code generator 21, the data determiner 23 determines whether it is a continuous fixed data section or a changing data section.

In the asynchronous state, this judgment is necessarily wrong.
That is, in the asynchronous state, the determination signal J1 is shifted in the direction of the arrow E1 or E2 in FIGS. 6A and 6B, and the determination signal J1 is related to the reception signal RX1.
Is "1" in the section corresponding to the change data T1, or "0" in the section corresponding to the continuous fixed data P1.
And so on.

However, when originally asynchronous, the correlation values CA1 and CB1 obtained by the adders 24 and 25 accumulatively adding the operation results EC1 of the product-sum operation unit 22 for the period corresponding to the length of the correlation section 1. Is also very small, corresponding to the interference power and noise.

Therefore, when asynchronous, C0 and C1 are small and the correlation power CP1 is also small, so that CP1 does not exceed the threshold value Th1. Correlation data composed of the correlation power CP1 and the correlation phase Φ1 that are less than the threshold Th1 are discarded by the synchronous position determination unit 28 determining that they correspond to the asynchronous position.

In the present embodiment, after the phase 0, the correlation phase Φ1 (Φ1 = 1) of the phase 1 is supplied. At this time, the cumulative addition value C of the adders 24 and 25 corresponding to the immediately preceding phase 0 is supplied.
A1 and CB1 are reset, a new cumulative addition is performed, and C1 is added and subtracted using CA1 and CB1 as a result.
0 and C1 are obtained, a new correlation power CP1 is obtained,
The comparison with the threshold value Th1 is performed.

After that, the same operation is repeated for all the phase candidates of the phases 2, 3, 4,..., 15.

In the case of the synchronous state, unlike the above-mentioned asynchronous state, FIGS. 6A and 6B are as shown in the drawing, and the judgment of the data judgment section 23 is accurate in accordance with the received signal RX1. It will be. That is, the judgment signal J1 is "1".
Section coincides with the continuous fixed data sections P1, P2, and P3, and the section in which J1 is “0” corresponds to the change data sections T1, T2.
Matches.

For example, when the correlation section 1 corresponds to the synchronization state, the judgment signal J1 is "1" for all the sections of the correlation section 1.
Is maintained, the calculation result CA1 of the addition unit (A) 24 becomes ΔP, and the calculation result CB1 of the addition unit (B) 25 becomes 0.

The ΔP means the sum of the product-sum operation results EC1 corresponding to the continuous fixed data section in one assumed correlation section, and here, the sum of the continuous fixed data 6 corresponding to the spreading code numbers 0 to 5 is 6 Is shown. The same applies to the following.

The correlation value after the addition and subtraction is C0 = C1 = ΣP. The correlation power of both the one corresponding to C0 and the one corresponding to C1 is obtained by dividing the 6 (= ΣP) by the correlation length 6. Indicates 1 which is a squared value. Therefore, the correlation power comparing section 27 outputs one of the correlation powers as CP1.

Although it is impossible in the present embodiment, assuming a case where the change data section is longer and the correlation section is shorter, the decision signal J1 indicates "0" indicating change data over the entire section of one correlation section. In this case, the correlation value becomes C0 = −C1 = ΔT, but the correlation powers become equal.
What is necessary is just to output any correlation power as CP1.

The ΔT means the sum of the product-sum operation results EC1 corresponding to the change data section in one assumed correlation section. The same applies to the following.

On the other hand, when the correlation section 2 corresponds to the synchronization state, the judgment signal J1 becomes an accurate signal that matches the reception signal RX1 of FIG.
In 5, 8, and 9, "1" indicates a continuous fixed data section, and in 6, 6 of the spreading code number N1, "0" indicates a changing data section.

In this case, the operation results of the adders 24 and 25 are CA1 = ΣP (= 4), CB
1 = ΣT (= 2, −2), and the result of addition / subtraction is C0 =
ΣP + ΣT, C1 = ΣP-ΣT.

Since the continuous fixed data P1 and P2 are "1", when the change data T1 is "1", C0 = 1 and C1
= 1/9 (= (1/3) ² ) and C0 = 1 is larger, so the correlation power comparing section 27 outputs the correlation power 1 based on C0 as CP1.

Conversely, when the change data T1 is "-1",
C0 = 1/9 and C1 = 1, and the correlation power comparison unit 27 selects and outputs the correlation power based on C1 as CP1. Again CP1 is 1 (= C1 ^2).

Therefore, in the present embodiment, even when continuous fixed data and changed data are mixed in one correlation section (correlation calculation section), the processing gain corresponding to the length of the correlation section, ie, the processing gain in the correlation section, The same processing gain as when only continuous fixed data exists,
It does not degrade the characteristics of synchronization acquisition.

By performing the same processing for all the phase candidates, when the correlation calculation for all the phase candidates is completed, the synchronization position Θ1 of the spread code is determined and output from the held correlation data.

In this determination, as described above, among the correlation data held by the synchronization position determination unit 28, the correlation phase Φ1 corresponding to the correlation data having the largest correlation power is determined as the synchronization position Θ1.

In the above description, the case where the code length of one cycle of the spreading code PN1 is 16 is shown for simplicity. It is about 30,000.

(B-3) Effects of the Second Embodiment According to the present embodiment, the probability dependency existing in the first embodiment is removed, and it is determined whether the change data exists in the correlation section. Without any synchronization, the same correlation power can be ensured as long as there is only continuous fixed data in the one correlation section, and the time from the state of indeterminate synchronization to the completion of acquisition is always ensured. It is possible to shorten a certain so-called retraction time.

Further, according to the present embodiment, it is possible to use a longer correlation section than the section (correlation section) for performing the correlation operation of the first embodiment, and to reduce the processing gain according to this length. It is possible to increase.

(C) Third Embodiment In this embodiment, almost the same functions as those in the second embodiment are realized with a simpler configuration.

(C-1) Configuration and Operation of Third Embodiment FIG. 5 shows the configuration of the synchronization acquisition circuit 30 of this embodiment. The synchronization acquisition circuit 30 can be mounted on a mobile communication terminal or the like similarly to the synchronization acquisition circuit 20.

The structure of the received signal RX2 received and processed by the synchronization acquisition circuit 30 may be the same as that of the received signal RX1 shown in FIG.

The spreading code number N2 of the present embodiment corresponds to the spreading code number N1, and the arrangement pattern can be specified by this number N2.

In FIG. 5, the configuration of the main functional blocks of the synchronization acquisition circuit 30 is almost the same as that of the synchronization acquisition circuit 20 of the second embodiment. .

That is, the spreading code generator 31 corresponds to the spreading code generator 21, the product-sum operation unit 32 corresponds to the product-sum operation unit 22, and the data judgment unit 33 corresponds to the data judgment unit 23. , The adding section 34 corresponds to the adding section (A) 24, and the correlation power calculating section 37 corresponds to the correlation power comparing section 27.
And the synchronous position determining unit 38
8, the input terminal 3A corresponds to the input terminal 2A, the input terminal 3B corresponds to the input terminal 2B, the output terminal 3C corresponds to the output terminal 2C, and the correlation operation unit 30A
Corresponds to the correlation calculator 20A, and the correlation power calculator 30A
B corresponds to the correlation power calculator 20B.

Further, the correlation phase Φ2 corresponds to the correlation phase Φ1, the spreading code PN2 corresponds to the spreading code PN1, the judgment signal J2 corresponds to the judgment signal J1, and the operation result EC2 corresponds to the operation result EC1. Corresponding, correlation value CA2
Corresponds to the correlation value CA1, the correlation power CP2 corresponds to the correlation power CP1, and the threshold value Th2 corresponds to the threshold value Th1.

However, the second embodiment differs from the second embodiment in the configuration of the correlation power calculator 30B, and corresponds to the adder 25 and the adder / subtractor 26 for accumulating the product-sum operation of the change data. There is no component to perform.

Therefore, in this embodiment, the judgment signal J
Only when 2 is "1", the adding unit 34 accumulatively adds the calculation result EC2. When the determination signal J2 is "0", the calculation result EC2 is ignored. Only the correlation power is calculated from the cumulative addition value CA2, and the comparison operation as in the correlation power comparison unit 27 is not performed.

Next, the operation of the synchronization acquisition circuit 30 will be considered, taking as an example the case where the correlation section (2) in FIG. 6C corresponds to the synchronization position.

Conventionally, the correlation power CC corresponding to the correlation section 2 at the synchronous position is ((ΣT1 + ΣP) / 6) ＾ 2. Therefore, when T1 = “1”, ΔT1 + ΔP
= 1 × 2 + 1 × 4, the conventional correlation power CC is 1, and when T = “− 1”, ΔT1 + ΔP = (− 1)
Since it is × 2 + 1 × 4, the correlation power CC is 1/9.

That is, the conventional correlation power CC varies from 1/9 of the minimum value to 1 of the maximum value according to the value of the change data.

On the other hand, in the present embodiment, when a correlation operation with a correlation length of 6 corresponding to the conventional correlation section 2 is performed, when the spread code number N1 is 4 or 5, the determination signal J2 is “1”. The adder 34 accumulates the operation result EC2 to be 1 ".

Subsequently, when the spread code number is 6 or 7, the judgment signal J2 becomes "0", and the adder 34 ignores the operation result EC2 without accumulating it.

In the case of the spread code numbers 8 and 9, the determination signal J2 becomes "1" again, and the operation result EC2 is cumulatively added to the adder 34, but the adder 34 still corresponds to the correlation length 4. Since only the calculation result EC2 is accumulated, the spreading code numbers 10, 9 are followed by the spreading code numbers 10,
11 (the judgment signal J2 is "1").
The cumulative addition of 2 is performed.

That is, the correlation section is as shown in correlation section 3 in FIG. The section marked with “x” in the correlation section 3 is a section in which the determination signal J2 is “0” and the accumulator 34 does not perform the cumulative addition.

Therefore, the correlation power CP2 of the synchronization acquisition circuit 30 corresponding to the correlation section 3 is ((ΣP) / 6) ＾ 2
= 1. The correlation power CP2 does not fluctuate according to the value of the change data T1, and is always “1”.

(C-2) Effects of the Third Embodiment According to the present embodiment, effects equivalent to those of the second embodiment can be obtained with a simpler configuration than the second embodiment.

(D) Other Embodiments In the above description, the correlation unit 2 or the spreading code generation unit 2
Although the phase of the spread code generated in 1, 31 is changed, the phase relationship (phase difference) is a relative concept between the received signal and the spread code. May be changed using a variable delay circuit or the like, and both the phase of the received signal and the phase of the spread code may be changed.

Further, in order to efficiently read out the already stored correlation data of the same phase, for example, when the write position determination section 5 stores the correlation data in the synchronous position candidate storage section 6, an address corresponding to the phase is used. A number may be specified, or a table containing data indicating the relationship between the address number of the synchronization position candidate storage unit 6 and the stored phase may be prepared.

Furthermore, it is not an essential requirement of the present invention that a pilot signal section is periodically inserted into the received code sequence.

The reason is that in the first embodiment, there is a section in which the same value is continuous (also continuous fixed data) in the communication data section, and this section is used for the convenience of the user.
Depending on the communication situation, there is a possibility that it may be repeated periodically, if there is a sudden continuous fixed data, or if there is a section where the value change frequency is small and almost continuous fixed data,
This is because synchronization acquisition can be performed based on a correlation operation with this section.

On the other hand, in the second and third embodiments, where the pilot signal section and the changing data section are arranged in the spread code sequence (ie, the arrangement pattern)
Is recognized on the synchronization acquisition circuit side, it is possible to perform the correlation operation while distinguishing between the pilot signal section and the change data section even if they are not periodically inserted.

The spreading code numbers N1 and N2 of the second and third embodiments are generated by counters operating based on the correlation phase information Φ1 and Φ2 of the spreading codes PN1 and PN2. , 31 may be used to generate the spread code numbers N1 and N2.

Further, as described above, if the spreading code generators 21 and 31 use a shift register, the counter may generate a spreading code number from the register value of the shift register.

The counter corresponds to the spreading code generator 2.
If the reference numerals 1 and 31 use a memory such as the correlation phase storage unit 1 of the first embodiment, the spreading code number may be generated from the address information of the memory.

In the above embodiment, CDMA has been described, but the present invention can be applied to spread spectrum other than CDMA.

In the above embodiment, hardware is used. However, the present invention can be realized by using software.

That is, according to the present invention, a correlation value is obtained by performing a correlation operation while shifting the phase relationship between a capture spreading code sequence generated on the receiving side and a received code sequence, and based on the correlation value. The synchronization acquisition apparatus and method for determining the synchronization position between a reception code sequence and the acquisition spread code sequence can be widely applied.

Further, according to the present invention, a variable data section and a fixed data section are arranged in a predetermined pattern on a transmission spreading code sequence used for spreading on the transmission side, and the receiving side recognizing the predetermined pattern is arranged. Then, while changing the phase relationship between the reception-side spread code sequence and the reception signal, which are the same code sequence as the transmission-side spread code sequence, the correlation operation is performed to obtain a correlation value, and the code is determined based on the correlation value. A synchronization acquisition device or a synchronization acquisition method for establishing synchronization can be widely applied.

[0185]

As described in detail above, the first and the second
According to the invention of the above, since the correlation value is obtained by changing the generation phase of the spread code sequence a plurality of times on the receiving side, in what radio wave environment (propagation path) and under what type of received signal is received However, any of the correlation operations is likely to provide a highly reliable correlation value, and is effective in preventing a situation in which a highly reliable correlation value cannot be obtained for at least a long period of time. Therefore, according to the present invention, it is possible to increase the synchronization acquisition rate and improve the reliability.

Further, the present invention can be realized on a small scale for the functions.

Further, according to the third and fourth aspects of the present invention, the probability dependence existing in the first and second aspects of the present invention is eliminated, and the variable data and the fixed data are mixed in the section (correlation section) where the correlation operation is performed. Irrespective of whether or not the correlation is performed, a sufficiently high correlation power can be obtained at the synchronous position.

Therefore, in the third and fourth aspects, the first,
Compared to the second invention, the so-called pull-in time, which is the time from the state of indeterminate synchronization to the completion of acquisition, can be reduced, and the reliability of synchronization acquisition is further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a synchronization acquisition circuit according to a first embodiment.

FIG. 2 is a time chart illustrating an operation of the synchronization acquisition circuit according to the first embodiment.

FIG. 3 is a schematic diagram for explaining the meaning of a phase.

FIG. 4 is a block diagram illustrating a configuration of a synchronization acquisition circuit according to a second embodiment.

FIG. 5 is a block diagram illustrating a configuration of a synchronization acquisition circuit according to a third embodiment.

FIG. 6 is a time chart for explaining the operation of the second and third embodiments.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Correlation phase storage part, 2 ... Correlation part, 3 ... Counter part, 4
... Synchronization position candidate selection unit, 5 ... Write position determination unit, 6 ...
Synchronization position candidate storage unit, 7: synchronization position determination unit, AS: reception signal, CC1 to CC3: correlation operation, 20, 30: synchronization acquisition circuit, 20A, 30A: correlation operation unit, 20B, 30B
... Correlation power calculator, 21, 31... Spreading code generator, 2
2, 32 ... product-sum operation unit, 23, 33 ... data judgment unit, 2
4, 25, 34 addition section, 28, 38 synchronization position determination section, J1, J2 determination signal, EC1, EC2 product sum operation result, CA1, CA2, CB1 correlation value, CP1, CP
2 ... correlation power, Φ1, Φ2 ... correlation phase, Θ1, Θ2 ... synchronization position, RX1, RX2 ... reception signal.

Continued on the front page F term (reference) 5K022 EE02 EE36 5K047 AA11 BB01 GG34 GG37 HH01 HH15 HH21

Claims (12)

[Claims] 1. A synchronization acquisition apparatus for performing a correlation operation on a spread code sequence generated on a receiving side and a received signal while shifting the phase relationship therebetween to obtain a correlation value, and establishing code synchronization based on the correlation value. In the above, the spread code sequence, which is the same as the spread code sequence used for spreading on the transmission side, is provided with correlation information forming means for changing the generation phase on the reception side a plurality of times to obtain the correlation value. Synchronous acquisition device. 2. The synchronization acquisition device according to claim 1, wherein the correlation information forming means includes: a phase memory storing the generated phase as phase data in each memory address; and a memory address of the phase memory in order of an address number. An address decoder for specifying an address, wherein a set of correlation information is formed from the correlation power of the correlation value and the phase data. 3. The synchronization acquisition device according to claim 2, wherein: a plurality of sets of correlation information obtained by said correlation information forming means are stored in corresponding memory addresses for each set; At this time, a plurality of sets of correlation information corresponding to the same phase data are provided with storage selecting means for selecting only data having a high correlation power as the synchronization position candidate data, and processing so that the storage is performed. A synchronization acquisition device. 4. The synchronous acquisition device according to claim 3, wherein said accumulation selecting means excludes the correlation information corresponding to the asynchronous position by comparing a predetermined threshold value with the correlation power of the corresponding correlation information. Means, and a selecting means for performing a selecting process for selecting a more reliable one between the already stored synchronization position candidates and the corresponding correlation information not excluded by the exclusion process. Synchronous acquisition device. 5. A synchronization acquisition method for calculating a correlation value by performing a correlation operation on these signals while shifting a phase relationship between a spread code sequence generated on a receiving side and a received signal, and establishing code synchronization based on the correlation value. In the above, for the spreading code sequence that is the same as the spreading code sequence used for spreading on the transmitting side, the receiving side performs a correlation information forming process of changing the generated phase a plurality of times to obtain the correlation value. Synchronous acquisition method. 6. The synchronization acquisition method according to claim 5, wherein in the correlation information forming process, the generated phase is stored as phase data in each memory address of a phase memory, and the memory addresses of the phase memory are arranged in order of address number. Addressing, and forming a set of correlation information from the correlation power of the correlation value and the phase data. 7. The synchronization acquisition method according to claim 6, wherein a plurality of sets of correlation information obtained by the correlation information forming process are stored in corresponding memory addresses of a storage memory in units of each set. At this time, a plurality of sets of correlation information corresponding to the same phase data are obtained by selecting only those having a high correlation power as synchronization position candidate data, and then processing so that the accumulation is performed. Method. 8. The synchronization acquisition method according to claim 7, wherein the synchronization position candidate data is selected by first comparing the correlation information corresponding to the asynchronous position by comparing a predetermined threshold value with the correlation power of the corresponding correlation information. A synchronization acquisition method characterized in that a highly reliable one is selected between a synchronization position candidate that has already been accumulated and the corresponding correlation information that has not been eliminated in the elimination process. 9. A changing data section and a fixed data section are arranged in a predetermined pattern on a transmission-side spreading code sequence used for spreading on the transmission side, and the receiving side recognizing the predetermined pattern performs While changing the phase relationship between the reception-side spread code sequence and the reception-side spread code sequence, which are the same code sequence as the transmission-side spread code sequence, these correlation operations are performed to obtain a correlation value, and code synchronization is established based on the correlation value. A spread code sequence generating means for generating the receiving-side spread code sequence in response to the change of the phase relationship; and performing a correlation operation between the receive-side spread code sequence and the received signal by a predetermined correlation operation. Correlation calculation means executed for each section; Correlation calculation at each time point corresponds to the change data section or the fixed data section corresponding to the change of the phase relationship and a predetermined pattern. Interval determination means for determining whether or not, according to the determination, correlation processing means for preventing the cancellation of these by calculating and processing the correlation calculation of the fixed data section and the correlation calculation of the change data section. Features synchronization acquisition device. 10. The synchronization acquisition device according to claim 9, wherein the correlation processing means accumulatively adds a correlation value obtained as a result of a correlation operation corresponding to the fixed data section according to the determination of the section determination means. The fixed section accumulating means for generating a fixed section accumulated value, and accumulatively adding the correlation value obtained as a result of the correlation operation corresponding to the changed data section according to the determination, thereby obtaining the changed section accumulated value. A changing section accumulating means for generating, an adding / subtracting means for generating an addition result and a subtraction result of the fixed section accumulating value and the changing section accumulative value, based on a larger absolute value of the addition result or the subtraction result, A synchronization acquisition device comprising: synchronization determination means for determining synchronization or non-synchronization by comparing with a predetermined threshold value. 11. The synchronization acquisition device according to claim 9, wherein the correlation processing means accumulatively adds a correlation value obtained as a result of a correlation operation corresponding to the fixed data section according to the determination of the section determination means. A fixed section accumulating means for generating a fixed section accumulated value, and a synchronization determining means for determining synchronization or non-synchronization by comparing with a predetermined threshold value based on the addition result. apparatus. 12. A variable data section and a fixed data section are arranged in a predetermined pattern on a transmission-side spreading code sequence used for spreading on a transmission side, and the reception side recognizing the predetermined pattern performs While changing the phase relationship between the reception-side spreading code sequence and the reception signal, which are the same code sequence as the transmission-side spreading code sequence, perform a correlation operation to obtain a correlation value,
In a synchronization acquisition method of establishing code synchronization based on the correlation value, generating the receiving-side spread code sequence in accordance with the change in the phase relationship, performing a correlation operation between the receive-side spread code sequence and the received signal, It is executed for each predetermined correlation operation section, and it is determined whether the correlation operation at each time point corresponds to the change data section or the fixed data section corresponding to the change of the phase relationship and the predetermined pattern. A synchronization acquisition method for identifying and processing a correlation operation in the fixed data section and a correlation operation in the changed data section in accordance with the determination, thereby preventing cancellation of these.