JP3411836B2 - Synchronization acquisition device and synchronization acquisition method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronization acquisition device and a synchronization acquisition method in CDMA mobile communication.

[0002]

2. Description of the Related Art CDMA (Code Division Multiple Access) is used as a multiple access system for the next-generation mobile communication system.
Is being developed. In this CDMA cellular system, it is necessary to perform a cell search for initial synchronization establishment work when the mobile station is powered on and for cell switching (handover) accompanying movement.

A comma-free method is used as a synchronization acquisition method in this cell search. The comma-free method spreads information using a code called comma-free arranged with regularity in one frame,
It is a method of identifying the frame synchronization and spreading code using the regularity. Hereinafter, this comma-free system synchronization acquisition method will be described with reference to FIGS. 10 to 12.

The synchronization acquisition method in CDMA has three stages: slot timing detection, frame timing detection, and spreading code identification.

Slot Timing Detection Normally, in CDMA, the first synchronization channel is used.
A sync channel and a second sync channel are provided. Here, the slot timing is detected using the first synchronization channel. In the signal of the first synchronization channel, one specific symbol in one slot is spread only by the search code common to all base stations. The slot timing is detected using this search code. The search code is one of the three spreading codes used in CDMA, and the other two are called scrambling code and spreading code.

Specifically, the detection of the slot timing is performed in the process as shown in FIG. In ST1,
Data for one slot in the frame of received data is fetched. In ST2, the correlation value between the data for one symbol and the common spreading code is calculated. S
At T3, the phase of the common search code is shifted. In ST4, it is determined whether the correlation processing has been completed for one frame. If one frame has not been completed, the process returns to ST2 to perform correlation processing. If the correlation processing is completed for one frame in ST4, the peak of the correlation value of the correlation processing for one frame is detected in ST5 to detect the slot timing.

Frame Timing Detection (Search Code Group Identification) Here, frame timing detection and search code group identification are performed using the second synchronization channel. Second
In the synchronization channel, one symbol at the head of all slots in one frame is spread with a search code. As shown in FIG. 13, there are 32 groups of search codes arranged for each slot. A search code group is identified using this search code, and then the frame timing is detected from the identified one search code group.

Specifically, the detection of the slot timing is performed in the process as shown in FIG. In ST11, data for one frame is fetched based on the slot timing in the data frame. In ST14,
Correlation processing is performed between the first symbol of each slot and the search code to calculate the correlation value. This correlation processing is performed for search codes 1 to 17, and the respective search codes are performed on slots 1 to 16.
Therefore, the correlation processing of ST14 is performed with search codes 1 to 1.
The process is repeated for 7 slots and repeated for 16 slots (ST12 to ST16). These correlation values are stored.

Then, in ST19, the correlation values for 16 slots for the corresponding search code are integrated for each group according to the search code arrangement table of FIG. Then, the processing of ST19 is performed for the integration leading slot 1
Repeat 16 times, search code group 32
Repeat for each piece (ST17 to ST21). Then
The surfcode group and the frame head are detected from the search code arrangement and the maximum value of the integration result in FIG. 13 (ST2
2).

Scrambling Code Identification Here, one scrambling code is identified from the 16 scrambling code candidates determined from the search code group identified in. Specifically, scrambling code identification is performed in the process shown in FIG.

In ST32, the correlation value between the data for four symbols and the scrambling code is calculated according to the identified frame timing. This process is repeated for 16 scrambling codes belonging to the identified search code group (ST31 to ST33).
Next, in ST34, the one with the maximum correlation value among the correlation results is identified as a scrambling code.

[0012]

However, in the above synchronization acquisition method, the number of correlations is 16 × 17 = 272.
Therefore, the number of additions becomes 32 × 16 × 15 = 7680, and there is a problem that the processing amount required for processing becomes very large. This increase in the processing amount is likely to cause not only the processing time but also the hardware amount and the power consumption.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a synchronization acquisition apparatus and a synchronization acquisition method that require a small amount of processing at the time of cell search.

[0014]

In order to solve the above-mentioned problems, the inventor reduced the number of times of correlation processing by utilizing the following characteristics. That is, 32 types of search code groups are composed of 17 search codes, and the search code arrangement is derived from the (M, N) Reed-Solomon code. M in parentheses (M, N) indicates a cyclic code length, and N is a value obtained by subtracting the minimum Hamming distance from the cyclic code length and adding one.

Minimum Hamming distance (M−N + 1) here
Means that when any two different search code groups are compared with other cyclic codes, at least (M-
The N + 1) slot is different from the search code arrangement of other groups.

In other words, the characteristics described above are different from each other.
When comparing any consecutive N slots of a search code group of a type, the search code for at least one slot is different from the others. Therefore, the search code group can be identified and the frame timing can be obtained based on the information for N slots.

That is, while the essence of the present invention performs the correlation processing for M slots for each search code in the conventional processing, using the above characteristics, only N slots (M> N) are used. It is to identify the search code group by the correlation processing.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A synchronization acquisition apparatus according to a first aspect of the present invention includes means for detecting a slot timing using a first spreading code that is common to communication partners, and frame timing detection means. If the number of slots is smaller than the number of repeating slots of the second spreading code group,
And a means for identifying the spreading code group and detecting the frame timing, and a means for identifying the third spreading code belonging to the second spreading code group.

According to this configuration, since the second spreading code group is identified and the frame timing is detected with slots smaller than the repeating slot unit of the second spreading code group, the number of correlations and the number of additions are reduced. be able to. As a result, the required memory capacity can be reduced.

In the synchronization acquisition apparatus according to the second aspect of the present invention, in the first aspect, the means for identifying the second spreading code group and detecting the frame timing takes in according to the detected slot timing. Means for performing correlation processing between the data and the second spreading code, means for integrating the result of the correlation processing according to a predetermined second spreading code allocation table, and the second spreading code based on this integration result. And means for determining group identification and frame timing.

The predetermined second spreading code allocation table shows that at least one search code for at least one slot is obtained when comparing the numbers of slots of any two different types of search code groups which are smaller than the number of consecutive continuous slot units. Different from the others. Therefore, the search code group can be identified and the frame timing can be obtained based on the information for this slot. As a result, the number of correlations and the number of additions can be reduced. As a result, the required memory capacity can be reduced.

The synchronization acquisition apparatus according to the third aspect of the present invention has a configuration according to the second aspect, which is provided with means for averaging the correlation processing results of a plurality of times.

According to this structure, since the correlation range is narrow,
It is possible to more average the correlation value per unit time, and it is possible to enhance the ability to absorb the error generated by the fading phenomenon of the propagation path.

According to the second aspect, the synchronization acquisition apparatus according to the fourth aspect of the present invention is configured to select a predetermined number of large integration results and an integration result most likely from the selected integration results. And means for determining.

According to this structure, a plurality of probable search code groups and frame heads are selected, and the most probable one is selected, so that the frame timing can be detected more accurately in synchronization acquisition.

A communication terminal apparatus according to a fifth aspect of the present invention is characterized by including the synchronization acquisition apparatus according to any one of the first to fourth aspects. A base station apparatus according to a sixth aspect of the present invention is characterized by performing wireless communication with the communication terminal apparatus of the fifth aspect.

A synchronization acquisition method according to a seventh aspect of the present invention is a step of detecting a slot timing using a first spreading code common to a communication partner, and a second spreading for frame timing detection. Identifying the second spreading code group and detecting frame timing with a number of slots smaller than the number of repeating slots of the code group; and identifying a third spreading code belonging to the second spreading code group. , Are provided.

According to this method, since the second spreading code group is identified and the frame timing is detected with the number of slots smaller than the repeating slot unit of the second spreading code group, the number of correlations and the number of additions are reduced. can do. As a result, the required memory capacity can be reduced.

In the synchronization acquisition method according to the eighth aspect of the present invention, in the seventh aspect, the steps of identifying the second spreading code group and detecting the frame timing are captured according to the detected slot timing. A step of performing a correlation process between the data and the second spread code; a step of integrating the result of the correlation process according to a predetermined second spread code allocation table; and a step of integrating the second spread code from the integration result. Group identification and frame timing determination.

The predetermined second spreading code allocation table is such that, when comparing any consecutive and less than repetitive slot units of any two different kinds of search code groups, at least one slot of search code is Different from Therefore, the search code group can be identified and the frame timing can be obtained based on the information for this slot. As a result, the number of correlations and the number of additions can be reduced. As a result, the required memory capacity can be reduced.

The synchronization acquisition method according to the ninth aspect of the present invention comprises the step of averaging the correlation processing results of a plurality of times in the eighth aspect.

According to this method, since the correlation range is narrow,
It is possible to more average the correlation value per unit time, and it is possible to enhance the ability to absorb the error generated by the fading phenomenon of the propagation path.

In the synchronization acquisition method according to the tenth aspect of the present invention, in the eighth aspect, the step of selecting a predetermined number from the ones having the largest integration result and the most probable integration result are determined from the selected integration results. And a process.

According to this method, a plurality of probable search code groups and heads of frames are selected, and the most probable one is selected, so that the frame timing can be detected more accurately in synchronization acquisition.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. (Embodiment 1) FIG. 1 is a block diagram showing a schematic configuration of a wireless communication system including a synchronization acquisition apparatus according to an embodiment of the present invention. At the base station side, the control unit 101
Controls the error correction coding / decoding unit 102 to perform error correction coding processing and error correction decoding processing of transmission data. The error-correction coded signal is
The transmitting unit 103 performs a normal wireless transmission process, and the signal is transmitted from the antenna 105.

On the side of the terminal equipped with the synchronization acquisition apparatus according to the present invention, the signal received from the antenna 106 is sent to the modulation / demodulation processing unit 107 and the synchronization processing unit 109, and modulation processing and synchronization processing are performed respectively. That is, while the synchronization processing unit 109 performs synchronization acquisition and synchronization holding,
Modulation / demodulation processing unit 107 and error correction / voice codec unit 1
At 08, the signal is converted to voice and output from the microphone / speaker 111. Also, when sending audio,
The voice input from the speaker 111 is voice-encoded by the error correction / voice codec unit 108, and the modulation / demodulation processing unit 10
After being modulated at 7, the signal is transmitted from the antenna 106.

This synchronization processing unit 109 has the configuration shown in FIG. The memory 201 accumulates data for N (N is a positive integer) symbols (N = 3 in FIG. 2) and passes the data to N correlators 203. The code generator 202 also generates a search code and sends it to each correlator 203. N correlators 203 are provided and perform correlation processing between the symbol data accumulated in the memory 201 and the search code generated by the code generator 202. The number of times the correlation value is calculated is N × 17 times.

The averaging section 204 averages the correlation values obtained by the correlator 202. The memory 205 stores the averaged correlation values, and sends the correlation values to the integration / maximum value detection unit 207 based on the information sent from the memory 206 that stores the search code arrangement table. The integration / maximum value detection unit 207 adds the correlation values accumulated in the memory 205 for N slots, and sends the maximum value to the group / frame head detection unit 208. The number of additions is 32 × 16 × (N−
1). The group / frame head detection unit 208
The search code arrangement table of the memory 206 is referred to by using the maximum value of the integrated values to detect the search code group and the frame head.

A synchronization acquisition method in the synchronization acquisition device having the above configuration will be described with reference to FIGS. Here, the number of scrambling codes (M) is 16, and
The target number of slots (N) is 3. This synchronization acquisition method is characterized in that the number of slot loops is reduced, the number of slots for integration processing is reduced, and comparison processing is performed.

First, as the first step, slot timing detection is performed. Specifically, the detection of the slot timing is performed in the process shown in FIG. In ST302, data for one slot in the frame of the received data is fetched. In ST303, the correlation value between the data for one symbol and the common search code is calculated. ST
At 304, the phase of the common spreading code is shifted. In ST305, it is determined whether the correlation process is completed for one frame. If one frame has not ended, the process returns to ST303 to perform correlation processing.

The processing of ST302 to ST304 is performed by P1 (P
(1 is a positive integer of 2 or more) times, and the processing results of P1 times are averaged (ST301 to ST306). And ST
If the correlation processing is completed for one frame in 305, ST
At 306, the peak of the correlation value of the correlation processing for one frame is detected to detect the slot timing.

Next, the frame timing detection (search code group identification) which is the second step will be described.
The layout of the search code that can be applied to each slot is
As shown in FIG. 13, there are 32 groups in total.

Concretely, the detection of the slot timing is performed in the process as shown in FIG. In ST402, one frame of data is fetched based on the slot timing in the data frame. The captured data is stored in the memory 201 shown in FIG. ST4
In 05, the correlator 203 uses the search code generated by the code generator 202,
Correlation processing is performed between the symbol and the search code to calculate the correlation value. This correlation processing is performed with search codes 1 to 17
The search is performed for slots 1 to 3 for each search code. Therefore, ST405
Is repeated for 1 to 17 search codes and repeated for 3 slots (ST403 to ST).
407). The processing of ST402 to ST407 is performed as P2 (P2
Is a positive integer of 2 or more) times, and the processing results of P2 times are averaged (ST401 to ST408). These averaged correlation values are stored.

Next, in ST411, the correlation values for three slots for the corresponding search code are integrated for each group according to the search code arrangement table of FIG. Then, the processing of ST411 is repeated for 1 to 16 integration leading slots, and search code group 3
Repeat two times (ST409 to ST413). Then, the search code group and the frame head are detected from the search code arrangement and the maximum value of the integration result of FIG. 13 (ST414).

The step of detecting the surfcode group and the frame head is specifically carried out according to the step shown in FIG. In this step, the maximum integral value is 3
This is a step of detecting to which slot of which group the slot search code numbers belong, in the search code arrangement table shown in FIG.

In ST503, according to the search code arrangement table of FIG. 13, each search code group is compared with the numbers of the corresponding three slots of the search code to collate the numbers. In ST504, it is determined whether or not the numbers for all three slots match. If the numbers for all three slots match, the search code group and the beginning of the frame have been identified (ST50).
7). If the numbers of three slots do not match, the start positions of the three slots of the search code to be compared are shifted with respect to slots 1 to 16 and further comparison is performed. This process is performed over the search code groups 1 to 32 (ST501 to ST506) to detect the search code group and the frame head.

Next, scrambling code identification is performed as the third step. 1 from 16 scrambling code candidates confirmed from the identified search code group
Identify one scrambling code. In particular,
The scrambling code identification is performed in the process shown in FIG.

In ST603, the correlation value between the data for four symbols and the scrambling code is calculated according to the identified frame timing. Note that the number of symbols to be calculated is not limited to 4 symbols, and other numbers of symbols may be used. This process is repeated for 16 scrambling codes belonging to the identified search code group (ST602 to ST604). Next, in ST605, the one with the maximum correlation value among the correlation results is identified as a scrambling code.

In this way, the scrambling code can be identified, and the cell search can be performed accordingly. According to the above synchronization acquisition method, the number of correlations is 3 × 17 = 51, and the number of additions is 32 × 16 × 2 = 1.
It is 024. Therefore, as compared with the conventional comma-free method, the amount of correlation processing is reduced by 81.25%, which is 86.67.
% Addition processing amount decreases. This will reduce the required memory capacity by 81.75%.

That is, in the synchronization acquisition method according to the present embodiment, although some comparison processing is added, the number of times of correlation value calculation and the number of integration processing are reduced by 80% or more as compared with the conventional method, and a surprisingly high speed. Can be realized.

Further, in the synchronization acquisition method according to this embodiment, the averaging process is performed in the first to third stages.
In this synchronization acquisition method, since the range of the correlation processing is narrow, the averaging processing can be performed in a short time. That is, if averaging processing is performed by the conventional comma-free method, 16 slot times are required to perform averaging once, but in this synchronization acquisition method, the range of correlation processing is assumed to be 4 slots. In this case, the averaging process can be performed 4 times in 16 slot times. As a result, according to this synchronization acquisition method,
The number of times of averaging can be appropriately determined, and the error absorbing ability can be enhanced.

(Embodiment 2) In the present embodiment, a plurality of probable ones having a high correlation value with respect to several slots of the corresponding search code are selected, and the most probable one is selected. A case of selecting will be described with reference to FIG. 7. In the present embodiment, the first and third stages of synchronization acquisition are the same as those in the first embodiment, and the description thereof will be omitted. Here, the number of target slots (N) is 3 + S.

In the second stage of synchronization acquisition, ST702
Then, using the search code generated by the code generator 202, the correlator 203 performs the correlation process between the first symbol of each slot and the search code to calculate the correlation value. This correlation processing is performed for search codes 1 to 17, and further, to each slot 1 to 3 for each search code. Therefore, the correlation process of ST702 is repeated for 1 to 17 search codes and repeated for 3 + S slots. The processing of ST702 is performed P times (P is a positive integer of 2 or more), and the processing results of P times are averaged (ST701 to ST703). These correlation values are stored.

Then, in ST707, according to the search code arrangement table of FIG. 13, the correlation value for the integral calculation range 3 + M slots for the corresponding search code is integrated for each group. This integration is performed for 0 to SM slots. Then, this processing is performed by integrating the leading slot 1 to
Repeat 16 times and repeat 32 search code groups (ST704 to ST710).

Specifically, the processing is performed as shown in FIG. The example of FIG. 8 shows a case where M = 0, S = 2, and S−M = 2. For group 1, in the case of integration leading slot 0, integration is performed up to the integration leading slot in the slot being 0, 1, 2 (SM).
For group 1, in the case of integration leading slot 1, the integration is performed until the integration leading slot in the slot is 0, 1, 2 (S−M) by shifting one slot from the previous one. This processing is performed for the integration leading slots 1 to 16 and groups 1 to 32.

Next, in ST711, N candidates that can be the maximum value among the integration results are selected from those having a high integration value. In ST712, the search code group number and the frame head are calculated for each of the N candidates according to the flow chart shown in FIG.

In ST713, it is determined whether or not there is a predetermined number L or more of the obtained search code group number and the frame head that match each other. If a predetermined number L or more coincide with each other, the search code group number and the frame head are determined to be most likely, and the search code group and the frame head are determined (ST715). If the number of matching items is less than the predetermined number L, it is determined whether the number of M and the number of S are the same (ST7).
14).

If the number of M and the number of S are the same, the number of S is increased (ST717) and the correlation calculation is performed only for the additional slot. That is, the processing from ST710 is performed only for the additional slots. On the other hand, if the number of M and the number of S are not the same, increase the number of M (ST71
6), integral calculation is performed with the number of M changed. That is, the processing from ST704 is performed while the number of M is changed.

According to the above method, a plurality of probable search code groups and frame heads are selected, and the most probable one is selected from them, so that the frame timing detection can be performed more accurately in the second step in the synchronization acquisition. You can

(Embodiment 3) In this embodiment, a plurality of probable ones having a high correlation value with respect to several slots of the corresponding search code are selected, and the most probable one is selected. Another example of selection will be described with reference to FIG. In the present embodiment, the first and third stages of synchronization acquisition are the same as those in the first embodiment, and the description thereof will be omitted. Here, the number of target slots (N) is 3 + S.

Since ST901 to ST912 are the same as ST701 to ST712 in FIG. 7, description thereof will be omitted.

In ST913, it is determined whether or not the obtained search code group numbers match each other by a predetermined number L1 or more. Then, if the number of coincident items is equal to or greater than the predetermined number L1, it is further determined whether or not there are equal to or greater than the predetermined number of L2 items at the frame head (ST).
914). Then, if there are a predetermined number L2 or more that match each other, it is determined that the search code group number and the frame head are most likely, and the search code group and the frame head are determined (ST916).

When the number of search code groups that match each other is less than the predetermined number L1, the number of match code heads that match each other is the predetermined number L2.
If the number is less than the number, it is determined whether the number of M and the number of S are the same (ST915).

If the number of M and the number of S are the same, the number of S is increased (ST918) and the correlation calculation is performed only for the additional slot. That is, the processing from ST910 is performed only for the additional slots. On the other hand, if the number of M and the number of S are not the same, increase the number of M (ST91
7), integral calculation is performed with the number of M changed. That is, the processing from ST904 is performed while the number of M is changed.

According to the above method, a plurality of probable search code groups and frame heads are selected, and the most probable one is selected from them, so that the frame timing detection can be performed more accurately in the second step in the synchronization acquisition. You can

The synchronization acquisition device of the present invention can be applied to a communication terminal device such as a mobile station device or a base station device in a CDMA radio communication system.

The present invention is not limited to the first to third embodiments described above, but can be implemented with various modifications. For example, the present invention can be applied to the case where the fast Hadamard transform is used for the correlation value calculation process in the frame timing detection process of the synchronous acquisition.

In the above embodiment, the number of slots for correlation calculation is 5 (S
= 2), the number of search code slots to be compared is 3 (M =
Although the case of 0) has been described, the present invention can also be applied to the case where the number of slots for performing the correlation calculation is other than 5, and the number of slots of the search code to be compared is other than 3. In this case, if the number of slots is reduced, the amount of calculation is reduced, but the error rate increases, so it is preferable to perform averaging processing appropriately.

[0069]

As described above, the synchronization acquisition apparatus of the present invention reduces the number of slot loops at the time of synchronization acquisition,
Since the number of slots for performing integration processing is reduced, the processing amount for synchronization acquisition can be reduced, and the processing time for synchronization acquisition can be dramatically reduced. Further, in the synchronization acquisition device of the present invention, the amount of hardware of the synchronization processing unit can be reduced and the circuit scale can be remarkably reduced. realizable.

[Brief description of drawings]

FIG. 1 is a block diagram showing a wireless communication system using a synchronization acquisition device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a synchronization acquisition device according to the above embodiment.

FIG. 3 is a flowchart for explaining the operation of the first stage of the synchronization acquisition method according to the above embodiment.

FIG. 4 is a flowchart for explaining the operation of the second stage of the synchronization acquisition method according to the above embodiment.

FIG. 5 is a flowchart for explaining a part of the operation of the second stage of the synchronization acquisition method according to the above embodiment.

FIG. 6 is a flowchart for explaining the operation of the third stage of the synchronization acquisition method according to the above embodiment.

FIG. 7 is a flowchart for explaining the operation of the second stage of the synchronization acquisition method according to the second embodiment of the present invention.

FIG. 8 is a diagram for explaining the process of the second stage of the synchronization acquisition method according to the above embodiment.

FIG. 9 is a flowchart for explaining the operation of the second step of the synchronization acquisition method according to the third embodiment of the present invention.

FIG. 10 is a flowchart for explaining the operation of the first step of the conventional synchronization acquisition method.

FIG. 11 is a flowchart for explaining the operation of the second stage of the conventional synchronization acquisition method.

FIG. 12 is a flowchart for explaining the operation of the third step of the conventional synchronization acquisition method.

FIG. 13 is a diagram showing a search code group allocation table.

[Explanation of symbols]

201, 205, 206 memory 202 code generator 203 Correlator 204 Averaging unit 207 Integration / maximum value detector 208 Group / Frame start detector

Front Page Continuation (56) References JP 2000-152316 (JP, A) JP 2000-49755 (JP, A) Special Table 2002-523922 (JP, A) 3GPP, TS 25.213, April 1999 , V2.0.0, pp. 23-24 ▲ Higuchi Kenichi (2 others), Fast Cell Search Method Using Long Code Mask in Asynchronous Cellular between DS-CD MA Base Stations, IEICE Technical Report, January 23, 1997, Vol. 96 Bo. 481, pp. 57-63, RCS96-122 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04J 13/00-13/06 H04B 1/69-1/713 H04L 7/00 H04Q 7/36

Claims (10)

(57) [Claims] 1. Means for detecting slot timing using a first spreading code common to communication partners,
Means for identifying the second spreading code group and detecting the frame timing with a smaller number of slots than the repeating slot unit of the second spreading code group for frame timing detection; and a means for belonging to the second spreading code group. And a means for identifying the spreading code of No. 3, and a synchronization acquisition device. 2. The means for identifying the second spreading code group and detecting the frame timing includes the data acquired according to the detected slot timing and the second data.
Means for performing correlation processing with the spreading code of the second spreading code, means for integrating the result of the correlation processing according to a predetermined second spreading code allocation table, and identification of the second spreading code group from the integration result. The synchronization acquisition apparatus according to claim 1, further comprising: a unit that determines a frame timing. 3. The synchronization acquisition apparatus according to claim 2, further comprising means for averaging the results of the correlation processing performed a plurality of times. 4. The synchronization acquisition according to claim 2, further comprising: a means for selecting a predetermined number of integration results having a large integration result, and a means for determining a most likely integration result from the selected integration results. apparatus. 5. A communication terminal device comprising the synchronization acquisition device according to any one of claims 1 to 4. 6. A base station device which performs wireless communication with the communication terminal device according to claim 5. 7. A step of detecting slot timing using a first spreading code common to a communication partner,
Identifying the second spreading code group and detecting the frame timing with a number of slots smaller than the repeating slot unit of the second spreading code group for frame timing detection; And a step of identifying the spreading code of No. 3, and a synchronization acquisition method. 8. The step of identifying the second spreading code group and detecting the frame timing includes the data acquired according to the detected slot timing and the second data.
Performing a correlation process with the spread code of the second spread code, integrating the result of the correlation process according to a predetermined second spread code allocation table, and identifying the second spread code group from the integration result. 8. The synchronization acquisition method according to claim 7, further comprising the step of determining a frame timing. 9. The synchronization acquisition method according to claim 8, further comprising the step of averaging the correlation processing results of a plurality of times. 10. The synchronization acquisition according to claim 8, further comprising: a step of selecting a predetermined number of integration results having a large integration result, and a step of determining a most likely integration result from the selected integration results. Method.