JP2002246960A - Cdma radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for long code identification, without increasing the hardware scale. SOLUTION: On a transmission side, a mask symbol spread by a short code in common to all base stations is provided at equal intervals in one transmission frame, and a symbol spread by a long-code group identification short code is multiplexed with the mask symbol and transmitted according to a prescribed pattern. On a reception side, at detecting of the long-code group identification short code, the pattern of the multiplexed symbol is detected in a pattern detection 113, and a long-code phase is obtained. On the basis of the long-code phase, the long-code in a long code group is searched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an asynchronous CDMA radio communication system between base stations using a mobile terminal such as a mobile phone, and more particularly to a CDMA radio communication device for identifying a long code used in a base station.

[0002]

2. Description of the Related Art In an asynchronous CDMA cellular wireless communication system between base stations using mobile terminals such as a mobile phone and a car phone, initial synchronization is established when the power of the mobile terminal is turned on, and cell switching accompanying movement is performed. It is necessary to perform a cell search for handover).

In this cell search, a long code is partially masked out of a short code common to cells and a long code unique to each base station used for a downlink control channel signal, and the masked portion is correlated with a short code. By detecting the timing and the type of the long code.

Specifically, in an asynchronous CDMA cellular mobile communication system between base stations, a transmitting side (base station)
As a search code (search code), a symbol spread by a short code (CSC) common to each cell and a symbol spread by a long code group identification short code (GIC) corresponding to a group to which the long code of each cell belongs are used. Are multiplexed with a long code mask portion provided at equal intervals (for example, for each slot) in one frame for each slot and transmitted.

[0005] The receiving side (mobile terminal) first detects slot timing using a short code common to each cell. After that, long code candidates to be searched are limited using the long code group identification short code, and a long code specific to a cell is specified from the long code candidates.

FIG. 16 shows a conventional asynchronous CDMA between base stations.
FIG. 3 is a block diagram illustrating a configuration of an initial synchronization unit of a wireless communication device (mobile terminal) in the cellular mobile communication system. The signal transmitted from the base station is received by the mobile terminal and becomes an input signal 20. The input signal 20 is subjected to correlation processing in the matched filter 3 with a short code common to all base stations generated by the common short code generator 1.

[0007] The output of the matched filter 3 is converted into a power value by a power conversion unit 4, and this power value is averaged by an averaging unit 5. The power value of the correlation value required for averaging is stored in the memory 2. During a predetermined period, the maximum value of the averaged power values is detected by the maximum value detection unit 6, and the detected timing is set as the mask symbol timing by the mask symbol timing generation unit 7.

On the other hand, an input signal 20 is sent to a correlator 8 by a long code group identification short code generator 1.
The correlation processing is sequentially performed with the long code group identification short code sequentially generated in step 2 and the mask symbol timing. The output of each correlator 8 is a power converter 9
Is converted to a power value, and the power value obtained in a predetermined period is integrated by the integrator 10. Next, the maximum value detecting unit 11 detects the maximum value of the integrated power value, and identifies the long code group by the long code group identification short code of the maximum value. Note that the maximum value detection unit 1
The output of 1 is sent to the long code timing control section 21.

The input signal 20 is correlated by the correlator 15 between the long code and the short code generated by the long code × short code generator 19. As for the long code × short code generated by the long code × short code generation unit 19, the long code timing control unit 21 changes the phase of the long code in search code units (for example, in slot units). The long codes are sequentially selected from the long codes belonging to the long code group identified as described above.

The output of the correlator 15 is converted into a power value by a power conversion section 16 and the power value obtained during a predetermined period is converted into an integration section 1
7 is integrated. Next, the threshold value determining unit 18 determines whether or not the integral value exceeds the threshold value, identifies the long code when the integrated value exceeds the threshold value as the long code of the base station, and identifies the timing of the slot as the phase of the long code. .
That is, the correlation process is performed by changing the phase by the number of slots, and the correlation process is performed by sequentially changing the long codes belonging to the long code group until the integrated value of the correlation values of the short codes common to all base stations exceeds the threshold value. Thus, a cell search is performed.

[0011]

However, in the initial synchronization section of the conventional CDMA radio communication apparatus, the phases differ by the number of slots at the stage of identifying a long code from a long code group. Along with identification of the type, detection of the long code phase must be performed. Therefore, there is a problem that much time is required for long code identification, that is, initial synchronization. On the other hand, if the long code identification is processed in parallel by hardware, the time for long code identification can be reduced, but there is a problem that the hardware scale becomes enormous.

An object of the present invention is to provide a CDMA radio communication apparatus which can significantly reduce the time required for long code identification without increasing the hardware scale.

[0013]

SUMMARY OF THE INVENTION A CDMA radio communication apparatus according to the present invention comprises a frame composed of a plurality of slots, and a predetermined code of each slot is selected from a first code common to each slot and a plurality of second codes. A second code and a signal for receiving a signal in which the second code is arranged, wherein the means for specifying the slot timing of each slot using the first code, based on the specified slot timing, Means for specifying for each slot which of the plurality of second codes the second code arranged in each slot is based on, based on the sequence pattern of the plurality of second codes specified for each slot Means for identifying the frame timing and the long code group, and based on the identified frame timing,
Means for specifying a long code from a plurality of long codes belonging to the specified long code group.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A CDMA radio communication apparatus according to a first aspect of the present invention comprises: means for detecting a timing of a mask symbol used in a cell search using a long code mask; A configuration including means for identifying a long code group, means for detecting the phase of a long code from pattern data related to a mask symbol, and means for identifying a long code from the identified long code group is adopted.

According to this configuration, since the phase of the long code is detected from the pattern data relating to the mask symbol, there is no need to detect the phase of the long code by shifting each symbol, without requiring a huge amount of hardware. The detection of the long code phase can be shortened.

A CDMA radio communication apparatus according to a second aspect of the present invention, in the first aspect, adopts a configuration in which the pattern data is pattern data of a correlation value.

A CDMA radio communication apparatus according to a third aspect of the present invention, in the first aspect, adopts a configuration in which the pattern data is pattern data of long code phase information spread for the mask symbol.

[0018] A CDMA radio communication apparatus according to a fourth aspect of the present invention, in the first aspect, adopts a configuration in which the mask symbol is a symbol in which symbols spread by different short codes are multiplexed.

According to these configurations, since the pattern is a known pattern on the receiving side, the long code phase can be detected more accurately.

According to a fifth aspect of the present invention, there is provided a CDMA radio communication apparatus comprising: means for detecting a timing of a mask symbol used in a cell search using a long code mask; Means for detecting a phase and identifying a long code.

According to this configuration, since the phase of the long code is detected from the pattern data relating to the mask symbol and the long code is identified, the cell search can be performed more quickly.

In a CDMA radio communication apparatus according to a sixth aspect of the present invention, in the fifth aspect, the pattern data is pattern data at a position where a symbol spread by a different short code exists in one slot. Take.

According to this configuration, since the pattern is a known pattern on the receiving side, the phase of the long code can be detected more accurately and the long code can be identified.

According to a seventh aspect of the present invention, there is provided a CDMA radio communication apparatus comprising: means for detecting a timing of a mask symbol used in a cell search using a long code mask; And a means for detecting the phase of the long code and the type of the long code.

According to this configuration, the identification time of the long code group and the identification time of the type of the long code can be reduced, so that the initial synchronization time can be further reduced.

According to an eighth aspect of the present invention, there is provided a CDMA radio communication apparatus comprising: means for detecting a timing of a mask symbol used in a cell search using a long code mask; Means for identifying, means for detecting the phase of the long code in the detected long code group, means for identifying the long code from the identified long code group, means for identifying the long code group, A configuration having a memory for holding mask symbol data is employed.

According to this configuration, the time required for identifying a short code for identifying a long code group can be significantly reduced by time-division processing.

The CDMA radio communication apparatus according to the ninth aspect of the present invention has been identified as a means for detecting a phase of a long code from a positional relationship of a mask symbol used in a cell search using a long code mask. Means for identifying a long code from a long code group, wherein the mask symbol employs a configuration in which symbols spread by different short codes are present at different positions within one slot.

According to this configuration, since the long code group is identified in a short time from the positional relationship of the mask symbols, the initial synchronization time can be greatly reduced.

[0030] A communication terminal device according to a tenth aspect of the present invention comprises:
A configuration including the CDMA wireless communication device according to any one of the first to ninth aspects is employed.

The base station apparatus according to the eleventh aspect of the present invention employs a configuration for performing wireless communication with the communication terminal apparatus according to the tenth aspect.

A CDMA wireless communication system according to a twelfth aspect of the present invention includes a communication terminal apparatus according to a tenth aspect, a base station apparatus performing wireless communication with the communication terminal apparatus according to the tenth aspect,
Is adopted.

According to these configurations, the above-described CDMA
Since the wireless communication device is provided, cell search can be performed at high speed in a digital wireless communication system.

In a CDMA radio communication system according to a thirteenth aspect of the present invention, a long code is masked and first mask symbols spread only with a short code common to all base stations are provided at equal intervals in one frame, and a long code is provided. The second mask symbol, which is masked and spread only with the long code group identification short code, is applied to the first mask symbol according to a predetermined pattern.
Transmitting means for multiplexing and transmitting the multiplexed mask symbols on a mask symbol, means for correlating a received signal with a short code common to all the base stations to obtain a first correlation value, and detecting a maximum value of the first correlation value and Means for detecting the timing of the first mask symbol; means for sequentially obtaining a correlation between the second mask symbol and a candidate for a long code group identification short code to obtain a second correlation value; Means for determining a long code group as a long code group identification short code, and detecting a long code head position from a correlation pattern between the second mask symbol and the long code group identification short code to determine a long code phase. The long code in the long code group at the long code phase and the received signal Means for sequentially taking the correlations of the first and second correlation values, and a long code corresponding to a third correlation value exceeding a threshold value calculated from the maximum value of the first correlation values. Means for identifying
Is adopted.

According to this configuration, the head position of the long code is detected when the short code for long code group identification is detected, so that the detection time of the long code phase can be shortened.

In a CDMA radio communication system according to a fourteenth aspect of the present invention, a long code is masked, first mask symbols spread with a short code common to all base stations are provided at equal intervals in one frame, and the long code is masked. Transmitting means for providing a second mask symbol spread by a long code group identification short code after a predetermined symbol of the first mask symbol according to a predetermined pattern and transmitting the second mask symbol; and a correlation between a received signal and a short code common to all the base stations. Means for obtaining a first correlation value, means for detecting the maximum value of the first correlation value to detect the timing of the first mask symbol, and candidates for the second mask symbol and the long code group identification short code. Means for sequentially calculating the correlation with the second correlation value, and a candidate having the maximum second correlation value Means for determining a long code group as a code group identification short code and detecting a long code head position from a correlation pattern between the second mask symbol and the long code group identification short code to determine a long code phase; Means for sequentially obtaining a correlation between the long code in the long code group and the received signal by phase to obtain a third correlation value, and a third correlation value exceeding a threshold calculated from the maximum value of the first correlation value. Means for identifying the corresponding long code as the long code of the base station that transmitted the received signal,
Is adopted.

According to this configuration, the power of the correlation value of the mask symbol for achieving the initial synchronization can be increased.

[0038] In a CDMA radio communication system according to a fifteenth aspect of the present invention, in the thirteenth aspect, means for allocating long code phase information to the first mask symbol and spreading with a short code common to all the base stations, A configuration is further provided that includes means for demodulating the first mask symbol with a short code common to all the base stations to obtain demodulated data, and means for detecting a long code phase from a pattern of the demodulated data.

According to this configuration, since the long code phase information is spread on the mask symbol and transmitted, the time required for long code identification can be greatly reduced.

[0040] In a CDMA radio communication system according to a sixteenth aspect of the present invention, in the thirteenth aspect, means for allocating long code phase information to the second mask symbol and spreading it with a long code group identification short code, A configuration is further provided that includes means for demodulating the second mask symbol with a code group identification short code to obtain demodulated data, and means for detecting a long code phase from the pattern of the demodulated data.

According to this configuration, since the long code phase information is spread and transmitted to the mask symbol, the time required for long code identification can be greatly reduced.

[0042] In a CDMA radio communication system according to a seventeenth aspect of the present invention, in the thirteenth aspect, long code phase information is assigned to the first mask symbol and spread with a short code common to all the base stations. Means for allocating the long code phase information to two mask symbols and spreading with the long code group identification short code, and means for demodulating the first mask symbol with the short code common to all base stations to obtain first demodulated data When,
Means for demodulating the second mask symbol with the long code group identification short code to obtain second demodulated data, and detecting a long code phase from both the pattern of the first demodulated data and the pattern of the second demodulated data. Means is further provided.

According to this configuration, since the long code phase information is spread on the mask symbol and transmitted, the time required for long code identification can be greatly reduced.

[0044] In a CDMA radio communication system according to an eighteenth aspect of the present invention, in the thirteenth aspect, the buffer memory for holding the data of the second mask symbol, the second mask symbol held in the buffer memory, Means for correlating with the long code group identification short code in a time-division manner.

According to this configuration, the time required for identifying a short code for identifying a long code group can be greatly reduced by time division processing.

In a CDMA radio communication system according to a nineteenth aspect of the present invention, means for allocating long code group identification data to a mask symbol in which a long code is masked, spreading the data with a short code common to all base stations, and transmitting Means for detecting the timing of the mask symbol from the maximum value of the correlation value between the signal and the short code common to all base stations, and demodulating the mask symbol with the short code common to all base stations; Means for extracting the long code group identification data and determining a long code group and a long code phase from a pattern of the long code group identification data; and, at the long code phase, the received signal and a long code in the long code group. And the correlation value is calculated in sequence for all bases. The long code exceeds a threshold calculated from a common short code, employs a configuration and means for identifying a long code of the base station which transmitted the received signal.

According to this configuration, the long code group is determined from the long code group identification data of the mask symbol without using the long code group identification short code, so that the time for the initial synchronization can be reduced.

A CDMA radio communication system according to a twentieth aspect of the present invention comprises a first mask symbol in which a long code is masked and spread with only a short code common to all first base stations, and a second mask symbol common to all second base stations. Means for arranging and transmitting the second mask symbols spread only by the short code at different positions at equal intervals in one frame, and using a matched filter or a sliding correlator, the reception signal and the first base station Means for taking a correlation with a short code common to stations, detecting the timing of the first mask symbol from the maximum value of the correlation value, and calculating a correlation value between the received signal and the short code common to all the second base stations. A maximum value is detected, and from the positional relationship between the maximum values of the correlation values of the short code common to all of the first base stations and the short code common to all of the second base stations, b Means for judging a code group, and taking a correlation between the received signal and a candidate in the long code group by sequentially shifting the phase, and obtaining a correlation value based on a correlation value of a short code common to all the base stations. Means for identifying the long code exceeding the threshold value as the long code of the base station that transmitted the received signal.

According to this configuration, since the long code group is identified in a short time from the positional relationship of the mask symbols, the initial synchronization time can be significantly reduced.

A CDMA radio communication system according to a twenty-first aspect of the present invention is the CDMA radio communication system according to the twentieth aspect, wherein long code phase information is assigned to said first mask symbol and spread by only a short code common to all first base stations. Means for allocating long code phase information to the second mask symbol and spreading only with a short code common to all second base stations;
Means for detecting a long code phase using the information demodulated from the first mask symbol and the information demodulated from the second mask symbol, wherein the long code phase detects the received signal and a candidate in the long code group. Means for sequentially taking a correlation with, and identifying a long code whose correlation value exceeds a threshold obtained based on the correlation value of the short code common to all base stations as the long code of the base station that transmitted the received signal. Is further provided.

According to this configuration, since the long code phase is identified from the long code phase information of the mask symbol, the initial synchronization time can be greatly reduced.

A CDMA radio communication system according to a twenty-second aspect of the present invention is the CDMA radio communication system according to the twentieth aspect, wherein information of a long code type is assigned to said first mask symbol.
Means for spreading only with a short code common to all base stations, assigning the information of the long code type to the second mask symbol, and spreading only with a short code common to the second base station; Symbol and said second
Means for demodulating the mask symbol with the short code common to all the base stations, extracting the information of the long code type, determining a long code phase from a pattern of the information of the long code type, information of the long code group, Means for determining the type of the long code using the information on the type of the long code.

According to this configuration, since the identification time of the long code group and the identification time of the type of the long code can be reduced, the initial synchronization time can be further reduced.

The inventor paid attention to the correlation power value pattern and the spread data pattern on the receiving side, and found that a long code phase could be detected by using these patterns, and came to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, a CDMA wireless communication system in which base stations are asynchronous will be described.

(First Embodiment) In this embodiment, a CD for detecting the phase of a long code from a multiplexed pattern of mask symbols spread by two short codes.
The MA mobile communication system will be described.

FIG. 1 is a block diagram showing a schematic configuration of a CDMA radio communication system. In this system, on the base station side, a transmission signal is frame-structured by a frame configuration unit 201 according to a predetermined frame format, and transmitted from an antenna 203 via a radio unit 202. On the other hand, on the mobile terminal side,
4 via the radio unit 205 and the initial synchronization unit 206
Sent to In FIG. 1, the processing units specific to CDMA in the base station and the mobile terminal are the same as those in the normal case, and will not be described.

FIG. 2 is a circuit diagram showing a C according to the first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of an initial synchronization unit of the DMA wireless communication device (mobile terminal). In FIG. 2, the signal transmitted from the base station is received by the mobile terminal and the input signal 12
It becomes 0. The input signal 120 is the matched filter 103
In, a correlation process is performed between the short code common to all base stations generated by the short code generator 101 common to all base stations.

The output of matched filter 103 is converted into a power value by power conversion section 104, and this power value is averaged by averaging section 105. The power value of the correlation value required for averaging, for example, the data of the number of chips for one slot,
Stored in the memory 102. During a predetermined period, the maximum value of the averaged power values is detected by the maximum value detection unit 106, and the detected timing is set as the mask symbol timing by the mask symbol timing generation unit 107. Thus, the slot timing is detected, and at the same time, the symbol timing is also detected. Thus, the mask symbol timing step is completed.

On the other hand, the input signal 120 is correlated in the correlator 108 with the long code group identification short code generated by the long code group identification short code generator 112 at the mask symbol timing. The output of the correlator 108 is converted into a power value by a power conversion unit 109, and the power value obtained during a predetermined period
Integrated at 10. Next, the maximum value detection unit 111 detects the maximum value of the integrated power value, and identifies the long code group by the long code group identification short code of this maximum value. Note that the maximum value detection unit 1
The output of 11 is a long code x short code generator 1
It is sent to 19.

The output of the power conversion unit 109 is sent to a pattern detection unit 113, where a known pattern of a mask symbol for one frame is detected, and the phase of a long code (for example, the first slot of a long code) is detected. Is done. The result is sent to the long code timing generator 114, and the long code timing generator 114 determines the long code timing. The determined long code timing is sent to the long code × short code generation unit 119. Thus, the long code group identification step and the long code timing step are completed.

The input signal 120 is correlated with the long code × short code generated by the long code × short code generator 119 at the determined long code timing. The output of the correlator 115 is converted into a power value by the power conversion unit 116, and the power value obtained during a predetermined period is integrated by the integration unit 117. Next, threshold determining section 118 identifies the long code exceeding the threshold value among the maximum values detected by maximum value detecting section 106 as the long code of the base station. This completes the long code identification step.

In the above configuration, a sliding correlator may be used instead of the matched filter 103.

The operation in the initial synchronization section of the CDMA radio communication apparatus configured as described above will be described. First, on the transmission side (base station), as shown in FIG. 3, a frame configuration is performed on a transmission signal so that a mask symbol in which a long code is masked for each slot at equal intervals is provided. Here, in order to simplify the description, a case where a mask symbol is provided at the head of a slot will be described.

In the frame configuration shown in FIG. 3, a long code is repeated at a frame period, and the head of the long code is the head of the frame. Further, in this frame configuration, for a mask symbol, data spread only with a short code common to all base stations,
It is multiplexed with the data spread only with the long code group identification short code. On the other hand, other symbols are double-spread with a short code common to all base stations and a long code unique to the base station. However, since the data spread only with the long code group identification short code is multiplexed at a predetermined position in the symbol spread with the short code common to all base stations, it is a symbol spread with the short code common to all base stations. However, there is a portion where data spread only by the long code group identification short code is not multiplexed. This predetermined position is known by the base station and the mobile terminal.

On the receiving side (mobile terminal), cell search processing is performed in the order of mask symbol timing detection, long code group identification, and long code identification.

First, in the mask symbol timing detection step, the received data (input signal 120) is correlated with the short code common to all base stations by the matched filter 103, and the correlation value is output at the chip rate. Is done. The output data of the correlation value is converted into a power value by the power conversion unit 104. This power value is stored in the memory 102, and the power value stored in the memory 102 is
In 5, the data is added up for a plurality of slots and averaged a specified number of times.

The correlation value (power value) is, as shown in FIG.
It becomes maximum at the position of the mask symbol. Therefore, the power value averaged by averaging section 105 also becomes maximum at the position of the mask symbol. The maximum value is detected by the maximum value detection section 106, and the mask symbol timing, that is, the slot timing is detected by the mask symbol timing generation section 107 based on the maximum value.

Next, in the long code group identification step, at the detected mask symbol timing, the long code group identification short code generation section 112 sequentially assigns all the long code group identification short codes to one.
The correlation code is generated in units of frames, and the correlator 108 correlates the long code group identification short code with the mask symbol in the input signal. Integrator 110 integrates the correlation power value between the mask symbol for one frame and the short code for identifying a long code group. The maximum value detection unit 111 identifies the long code group identification short code having the largest integral value among all the long code group identification short codes as the long code group identification short code of the base station.

At this time, the leading slot of the frame is detected from the pattern of the correlation value (power value) of the mask symbol in one frame. In the transmitting frame,
The portion where the long code group identification short code is multiplexed in the mask symbol has a pattern as shown in FIG. The multiplexing pattern in this example is “111101111010
1100 ". FIG. 5 shows a state in which only the mask symbols are extracted and other symbols are omitted.

On the receiving side, the correlation power value of the mask symbol and the long code group identification short code in one frame becomes higher at the position where the symbols spread by the long code group identification short code are multiplexed, as shown in FIG. ing. This pattern is the same as the pattern of the portion where the long code group identification short code is multiplexed in the transmission side frame in FIG. Since this pattern can be identified, by detecting this pattern in the pattern detection unit 113, the frame position, that is, the long code phase can be detected. At this long code phase, the long code timing is obtained by the long code timing generation unit 114.

Next, in the long code identification step, the long code × short code generation unit 119 generates a long code × short code replica code at the obtained long code timing. At this time, the replica code is generated while sequentially changing the long code within the identified long code group. Then, the correlator 115 correlates the replica code with a symbol other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the integration unit 117 integrates the power value over a specified number of symbols. Threshold determination unit 11
In step 8, the threshold value calculated from the maximum value of the correlation power values of the short codes common to all base stations detected by the maximum value detection unit 106 is compared with the integral value, and the long code when the integral value exceeds the threshold value is determined. Identify the long code of the base station.

In the conventional method, in the long code identification step, the correlation value of the long codes must be obtained by the number of slots by shifting the phase of one long code in slot units. On the other hand, according to the method of this embodiment, 1
It is not necessary to take correlation values of long codes for one long code by the number of slots. Therefore, assuming that the number of slots is N, the method of the present embodiment requires 1 / N times the time required for the long code identification step as compared with the conventional method.

As described above, according to the present embodiment, on the transmitting side, the mask symbol spread by the long code group identification short code is added to the long code mask symbol spread by the short code common to all base stations in one frame. Multiplexed in a predetermined pattern and transmitted, the initial synchronization unit on the receiving side detects the phase of the long code by detecting the pattern in the long code group identification short code identification step. To detect. As a result, the time required for the initial synchronization can be significantly reduced.

(Second Embodiment) This embodiment relates to a CDMA radio communication apparatus for detecting the phase of a long code from pattern data spread by a short code common to all base stations and / or a long code group identification short code. explain.

FIG. 6 is a block diagram showing the configuration of the initial synchronization section of the CDMA radio communication apparatus (mobile terminal) according to the present embodiment. 6, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof will be omitted.

The output of the matched filter 103 in the mask symbol timing detection step is output to the data demodulation section 121.
The data included in the mask symbol spread by the short code common to all base stations is extracted by the data demodulation section 121 from the output. The extracted data is sent to the long code phase detection unit 123.

The output of the correlator 108 in the long code group identification step is sent to the data demodulation section 122, from which the data contained in the mask symbol spread with the long code group identification short code is extracted. The extracted data is sent to the long code phase detector 12
Sent to 3.

The long code phase detector 123 detects the long code phase from the data from the data demodulator 121 and / or the data demodulator 122. This long code phase is sent to long code timing generation section 114. When the data of the data demodulation unit 122 is used, the data demodulation unit 122 performs data demodulation after the long code group identification short code is identified.

The operation of the initial synchronization section of the CDMA radio communication apparatus having the above configuration will be described. First, on the transmitting side (base station), as shown in FIG. 7, a frame configuration is performed so that a mask symbol in which a long code is masked is provided for each slot at equal intervals. Here, in order to simplify the description, a case where a mask symbol is provided at the head of a slot will be described.

In the frame configuration shown in FIG. 7, a long code is repeated at a frame period, and the head of the long code is the head of the frame. Further, in this frame configuration, for a mask symbol, data spread only with a short code common to all base stations,
It is multiplexed with the data spread only with the long code group identification short code. On the other hand, other symbols are double-spread with a short code common to all base stations and a long code unique to the base station.

At this time, long code phase information is used as data spread by a short code common to all base stations and / or a long code group identification short code. The long code phase information (pattern data) is included in a closed state in a frame, and the same one is transmitted in each frame.

On the receiving side (mobile terminal), cell search processing is performed in the order of detection of long code timing, identification of long code group, and identification of long code.

First, in the long code timing detection step, the received data (input signal 120) is correlated with the short code common to all base stations by the matched filter 103, and the correlation value is output at the chip rate. Is done. The output data of the correlation value is converted into a power value by the power conversion unit 104. This power value is stored in the memory 102, and the power value stored in the memory 102 is
In 5, the data is added up for a plurality of slots and averaged a specified number of times.

The correlation value (power value) is, as shown in FIG.
It becomes maximum at the position of the mask symbol. Therefore, the power value averaged by averaging section 105 also becomes maximum at the position of the mask symbol. The maximum value is detected by the maximum value detection section 106, and the mask symbol timing, that is, the slot timing is detected by the mask symbol timing generation section 107 based on the maximum value.

The data demodulating section 121 demodulates the correlation output from the matched filter 103 for the short code common to all base stations only for the mask symbols, and extracts data. In this case, if the data pattern sent in advance is known, the long code phase can be detected from the phase of the extracted data by detecting the pattern of the data. Thereby, long code timing is obtained.

Next, in the long code group identification step, at the detected mask symbol timing, the long code group identification short code generating section 112 sequentially changes and generates all the long code group identification short codes, and the correlator 108. , The correlation between the long code group identification short code and the mask symbol in the input signal is calculated. Integrator 110 integrates the correlation power value between the mask symbol and the long code group identification short code by a specified number of symbols. The maximum value detection unit 111 identifies the long code group identification short code having the largest integral value among all the long code group identification short codes as the long code group identification short code of the base station.

Next, in the long code identification step, a long code × short code generation section 119 generates a long code × short code replica code at the obtained long code timing. At this time, the replica code is generated while sequentially changing the long code in the identified long code group. Then, the correlator 115 correlates the replica code with a symbol other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the integration unit 117 integrates the power value over a specified number of symbols. Threshold determination unit 11
In step 8, the threshold value calculated from the maximum value of the correlation power values of the short codes common to all base stations detected by the maximum value detection unit 106 is compared with the integral value, and the long code when the integral value exceeds the threshold value is determined. Identify the long code of the base station.

In the above method, after the long code group identification short code is identified, data spread by the long code group identification short code is extracted by using the data demodulation unit 122, and the long code phase is extracted from the pattern. May be detected.

As described above, according to the present embodiment, the transmitting side assigns the pattern data for detecting the long code phase to the long code mask symbol in one frame, and assigns the short code and / or common to all base stations. Alternatively, the signal is spread with the long code group identification short code and transmitted, and the output of the matched filter and / or
Alternatively, pattern data is extracted from the correlator output of the long code group identification short code, and the long code phase is detected from the pattern. As a result, it is not necessary to take the correlation values of the long codes for the number of slots for one long code, and the time required for the initial synchronization can be greatly reduced.

(Third Embodiment) In this embodiment, mask symbol data is held in a buffer memory, and correlation processing between this data and a long code group identification short code is performed in one slot by time division. A CDMA wireless communication device will be described.

FIG. 8 is a block diagram showing a configuration of the long code group identification short code identification section of the CDMA radio communication apparatus according to the present embodiment. In FIG. 8, FIG.
The same reference numerals as in FIG. 6 denote the same parts, and a description thereof will be omitted. The buffer memory 124 shown in FIG. 8 holds the data of the mask symbol of the input signal 120.

The operation of the long code group identification short code identification section having the above configuration will be described. Only the mask symbol data of the input signal 120 is stored in the buffer memory 124. In this case, the correlation between the mask symbol and the long code group identification short code may be obtained, so that only one symbol time is required for one long code group identification short code. Then, using the remaining time in one slot, the correlation between the contents of the buffer memory 124 and other long code group identification short codes is sequentially obtained, and the correlation of the long code group identification short codes is time-divided within one slot. Do.

As described above, according to the present embodiment, the initial synchronization section on the receiving side holds the mask symbol data in the buffer memory, and performs the long code group identification short code correlation processing in one slot in a time division manner. By doing so, the time required for long code group identification and short code identification can be significantly reduced.

(Fourth Embodiment) In the present embodiment, a frame in which a mask symbol spread with a short code common to all base stations and a mask symbol spread with a long code group identification short code are temporally separated. A CDMA wireless communication device that performs communication with the configuration will be described.

FIG. 9 is a diagram showing a frame format used in wireless communication according to the present embodiment. On the transmitting side, the frame format shown in FIG. 9 is created in the frame configuration unit. In this frame configuration, 1
Two mask symbols are provided in a slot, and a symbol spread with a short code common to all base stations and a symbol spread with a long code group identification short code are assigned to each mask symbol. In FIG. 9, the two mask symbols are provided consecutively in one slot to simplify the description.

On the receiving side, in the long code group identification step, the input signal and the long code group identification short are detected at a position one symbol after the mask symbol position detected from the correlation value of the short code common to all base stations in the timing detection step. Correlation between the code and the code is performed to identify a long code group identification short code.

In the present embodiment, since the mask symbol is divided into two in the frame, the correlation value and the correlation power value are doubled as compared with the case where the mask symbol is multiplexed and transmitted. Therefore, it is less likely to be affected by noise or fading. In this embodiment, a case has been described where the mask symbol spread by the long code group identification short code is one symbol after the mask symbol spread by the short code common to all base stations. If the positional relationship between the mask symbol spread by the code group identification short code and the mask symbol spread by the short code common to all base stations is determined in the frame format, that is, if it is patterned, Cell search can be performed.

As described above, according to the present embodiment, on the transmitting side of the radio communication system, a mask symbol spread with a short code common to all base stations and a mask symbol spread with a long code group identification short code are used. Since the transmission is divided into two, the correlation value and the correlation power value increase in the initial synchronization section on the receiving side. As a result, in this system, it is possible to reliably perform the initial synchronization in a state resistant to noise and the like.

(Fifth Embodiment) In this embodiment, a CDMA radio communication apparatus for detecting a long code group and a phase of a long code from pattern data spread by a short code common to all base stations will be described.

FIG. 10 is a block diagram showing the configuration of the initial synchronization section of the CDMA radio communication apparatus (mobile terminal) according to the present embodiment. 10, the same parts as those in FIG. 6 are denoted by the same reference numerals as those in FIG. 6, and description thereof will be omitted. The initial synchronization section shown in FIG. 10 has a configuration obtained by removing the configuration relating to the long code group identification step from the initial synchronization section shown in FIG. That is, the initial synchronization unit shown in FIG.
From the initial synchronization unit to the correlator 108 and the power conversion unit 1 shown in FIG.
09, a long code phase detection unit 123 except for an integration unit 110, a maximum value detection unit 111, a long code group identification short code generation unit 112, and a data demodulation unit 122.
, A configuration in which a long code group detection unit 126 is provided. The long code group detection unit 126
The long code group and the long code phase are detected from the data obtained by demodulating the output of the matched filter 103 by the data demodulation unit 121.

The operation of the initial synchronization section of the CDMA radio communication apparatus having the above configuration will be described. First, on the sending side,
As shown in FIG. 11, the transmission signal is frame-structured such that mask symbols in which a long code is masked for each slot are provided at equal intervals. Here, in order to simplify the description, a case where a mask symbol is provided at the head of a slot will be described.

In the frame configuration shown in FIG. 11, a long code is repeated at a frame period, and the head of the long code is the head of the frame. In this frame configuration, long code group identification data spread only with a short code common to all base stations is used as a mask symbol. On the other hand, other symbols are double-spread with a short code common to all base stations and a long code unique to the base station. Note that the long code group identification data is included in a closed state in a frame, and is transmitted repeatedly every frame.

On the receiving side (mobile terminal), as in the first embodiment, in the mask symbol timing detecting step, the matched filter 103 correlates the input signal 120 with the short code common to all base stations, and The timing of the mask symbol is obtained from the correlation value.

Next, in the long code group identification step, the data demodulation section 121
And demodulates the data of only the mask symbol in the correlation output from the data and extracts the pattern of the long code group identification data. Next, the long code group is identified and the long code phase is detected by matching the extracted pattern of the long code group identification data with the patterns of several types of long code group identification data known in advance. Thereby, long code timing is obtained.

Next, in the long code identification step, the long code × short code generation section 119 generates a replica code of the long code × short code at the obtained long code timing. At this time, the replica code is generated while sequentially changing the long code within the identified long code group. Then, the correlator 115 correlates the replica code with a symbol other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the integration unit 117 integrates the power value over a specified number of symbols. Threshold determination unit 11
In step 8, the threshold value calculated from the maximum value of the correlation power values of the short codes common to all base stations detected by the maximum value detection unit 106 is compared with the integral value, and the long code when the integral value exceeds the threshold value is determined. Identify the long code of the base station.

As described above, according to the present embodiment, the transmitting side transmits a long code mask symbol in which pattern data for long code group detection is spread by a short code common to all base stations, and the initial state of the receiving side is transmitted. In the synchronization section,
Extract the pattern data from the output of the matched filter,
The long code group is identified and the long code phase is detected from the pattern data. As a result, the time required for the initial synchronization can be greatly reduced, and the hardware can be reduced.

(Sixth Embodiment) In this embodiment, a CDMA radio communication apparatus for identifying a long code group from the positional relationship between two mask symbols will be described. FIG. 12 is a block diagram illustrating a configuration of an initial synchronization unit of the CDMA wireless communication device (mobile terminal) according to the present embodiment. 12, the same parts as those in FIG. 10 are denoted by the same reference numerals as those in FIG. 10, and the description thereof will be omitted. The initial synchronization unit shown in FIG. 12 has a configuration in which the data demodulation unit 121 and the long code timing generation unit 114 are removed from the initial synchronization unit shown in FIG. In the initial synchronization section, the long code group detection section 126 identifies a long code group from the output of the maximum value detection section 106, that is, the maximum value of the short codes common to all two base stations.

The operation of the initial synchronization section of the CDMA radio communication apparatus having the above configuration will be described. On the transmitting side, Figure 1
As shown in FIG. 3, the frame configuration is performed so that two mask symbols each masking a long code are provided in one slot. Here, in order to simplify the explanation, one mask symbol is set at the head of the slot, and the other mask symbol is provided in the slot. Specifically, a symbol spread only with the first short code common to all base stations is assigned to the leading mask symbol of the slot, and a symbol spread with the second common short code common to all base stations is assigned to the remaining mask symbols. assign. In this case, the positional relationship (pattern) between the two mask symbols in the slot corresponds to the long code group. Therefore, the long code group can be identified by identifying the positional relationship between the two mask symbols.

On the receiving side (mobile terminal), in the mask symbol timing detecting step, the input signal 120 is matched with the first common short code generated by the common short code generator 101 by the matched filter 103 and the first short code generator 101. Are correlated. The correlation output data is converted by the power conversion unit 104 into a power value. This power value is stored in the memory 102, and the power value stored in the memory 102 is added up by the averaging unit 105 for a plurality of slots,
It is averaged over a specified number of times. The maximum value of the averaged correlation power value is detected by the maximum value detection unit 106, and the mask symbol timing, that is, the slot timing is detected by the mask symbol timing generation unit 107 based on the maximum value.

Next, in the long code group identification step, the matched filter 103 correlates the input signal 120 with the second common short code generated by the common short code generation unit 101. The correlation output data is converted by the power conversion unit 104 into a power value.
This power value is stored in the memory 102, and the power value stored in the memory 102 is added up for a plurality of slots by the averaging unit 105 and averaged a specified number of times. The maximum value of the averaged power value is detected by the maximum value detection unit 106. The maximum value and the timing of the previously detected slot are sent to the long code group detection unit 126. Long code group detection section 126 uses the timing of the previously detected slot and the timing at which the maximum value is obtained to determine the positional relationship of the mask symbol in the slot (the symbol of the symbol for which the maximum correlation value is obtained within the slot). Position relationship), and identifies a long code group corresponding to the position relationship.

Next, in the long code identification step, one long code is correlated with the input signal while changing the phase by the number of slots, from the long code candidates included in the identified long code group. Until a long code whose integral value of the correlation power value exceeds the threshold is obtained by the threshold determination unit 118, the correlation process is performed by sequentially changing the long code from the candidates. The long code whose integral value exceeds the threshold is identified as the long code of the base station, and the timing of the slot is identified as the phase of the long code.

As described above, according to the present embodiment, the transmitting side transmits two mask symbols spread with the short code common to all base stations, and the initial synchronization unit on the receiving side transmits the long code group identification short code. , The long code group is detected from the positional relationship between the two mask symbols. As a result, the hardware scale can be reduced, and the initial synchronization time can be reduced.

In this embodiment, the case where two mask symbols are provided in the slot has been described.
In the present invention, the number of mask symbols in a slot may be three or more.

(Seventh Embodiment) In this embodiment, a CDMA radio communication apparatus for detecting a long code phase from a long code phase information pattern will be described.
FIG. 14 is a block diagram illustrating a configuration of an initial synchronization unit of the CDMA wireless communication device (mobile terminal) according to the present embodiment. In FIG. 14, the same parts as in FIG.
The same reference numerals as those of 0 denote the same parts, and a description thereof will be omitted. In the CDMA radio communication apparatus shown in FIG.
The long code phase detection unit 123 detects the long code phase using the data extracted in step 1.

The operation of the initial synchronization section of the CDMA radio communication apparatus having the above configuration will be described. On the sending side, the sixth
13, the frame configuration is performed so that two mask symbols in which a long code is masked are provided in one slot, as shown in FIG. Here, in order to simplify the explanation, one mask symbol is set at the head of the slot, and the other mask symbol is provided in the slot. Specifically, a symbol spread only with the first short code common to all base stations is assigned to the leading mask symbol of the slot, and a symbol spread with the second common short code common to all base stations is assigned to the remaining mask symbols. assign. In this case, the data spread by the short code common to all the first and second base stations includes a pattern giving long code phase information. Further, the positional relationship (pattern) between two mask symbols in a slot corresponds to a long code group. Therefore, the long code group can be identified by identifying the positional relationship between the two mask symbols.

On the receiving side (mobile terminal), in the mask symbol timing detecting step, the input signal 120 is matched with the first common short code generated by the common short code generation section 101 by the matched filter 103 and the first short code generating section 101. Is correlated. The correlation output data is converted by the power conversion unit 104 into a power value. This power value is stored in the memory 102, and the power value stored in the memory 102 is added up by the averaging unit 105 for a plurality of slots.
It is averaged over a specified number of times. The maximum value of the averaged correlation power value is detected by the maximum value detection unit 106, and the mask symbol timing, that is, the slot timing is detected by the mask symbol timing generation unit 107 based on the maximum value.

Next, in the long code group identification step, the matched filter 103 correlates the input signal 120 with the second common short code generated by the common short code generation unit 101. The correlation output data is converted by the power conversion unit 104 into a power value.
This power value is stored in the memory 102, and the power value stored in the memory 102 is added up for a plurality of slots by the averaging unit 105 and averaged a specified number of times. The maximum value of the averaged power value is detected by the maximum value detection unit 106. The maximum value and the timing of the previously detected slot are sent to the long code group detection unit 126. Long code group detection section 126 uses the timing of the previously detected slot and the timing at which the maximum value is obtained to determine the positional relationship of the mask symbol in the slot (the symbol of the symbol for which the maximum correlation value is obtained within the slot). Position relationship), and identifies a long code group corresponding to the position relationship.

The data demodulation section 121 performs data demodulation only on the mask symbols in the correlation output from the matched filter 103 to extract data.
Since this data is a known pattern that gives long code phase information, the long code phase (the first slot of the frame) can be detected from the phase of the extracted pattern data.

Next, in the long code identification step, from the long code candidates included in the identified long code group, the long code is sequentially changed with the detected long code phase to perform a correlation process with the input signal, thereby obtaining a correlation power value. And integrate the correlation power value. Threshold determination unit 11
Until a long code whose integral value of the correlation power value exceeds the threshold value is obtained in step 8, the correlation process is performed by sequentially changing the long code from the candidates. The long code whose integral value exceeds the threshold is identified as the long code of the base station.

As described above, according to the present embodiment, the transmitting side transmits two mask symbols having long code phase information spread by a short code common to all base stations, and the initial synchronization unit on the receiving side A long code group is detected from the positional relationship between two mask symbols without using a long code group identification short code, and a long code phase is detected from long code phase information. This allows
The hardware scale can be reduced, and the initial synchronization time can be reduced.

(Eighth Embodiment) In this embodiment, a CDMA for obtaining a long code type from a pattern giving a long code type and a long code group is described.
The wireless communication device will be described. FIG. 15 is a block diagram illustrating a configuration of an initial synchronization unit of the CDMA wireless communication device (mobile terminal) according to the present embodiment. 15, the same parts as those in FIG. 14 are denoted by the same reference numerals as in FIG. 14, and the description thereof will be omitted. In the CDMA radio communication apparatus shown in FIG. 15, a long code type detection unit 127 detects the type of a long code using the data extracted by data demodulation unit 121. The type of the long code is sent to the long code × short code generator 119.

The operation of the initial synchronization section of the CDMA radio communication apparatus having the above configuration will be described. On the sending side, the sixth
13, the frame configuration is performed such that two mask symbols each having a long code masked are provided in one slot, as shown in FIG. Here, in order to simplify the explanation, one mask symbol is set at the head of the slot, and the other mask symbol is provided in the slot. Specifically, a symbol spread only with the first common short code for all base stations is assigned to the leading mask symbol of the slot, and a symbol spread with the second common short code for all base stations is assigned to the remaining mask symbols. assign. In this case, the data spread by the short code common to all the first and second base stations includes a pattern giving the type of the long code. Further, the positional relationship (pattern) between two mask symbols in a slot corresponds to a long code group. Therefore, the long code group can be identified by identifying the positional relationship between the two mask symbols.

On the receiving side, as in the sixth embodiment, the slot timing is detected using the short code common to the first base station and the short code common to the second base station. Also, a long code group is identified from the positional relationship between two mask symbols in a slot.

At the same time, data demodulation section 121 performs data demodulation only on the mask symbols of the correlation output from matched filter 103 to extract pattern data. The long code phase detector 123 detects the type of the long code and the long code phase by pattern matching. In this way,
The identification of the long code group and the type and phase of the long code are obtained at one time. In this case, for confirmation, a correlation process may be performed with the input signal using the identified long code, and the threshold value may be determined in the same manner as in the above embodiment.

As described above, according to the present embodiment, the transmitting side transmits two mask symbols having the long code type information spread by the short code common to all base stations, and the initial synchronization unit on the receiving side A long symbol type and a long code phase are detected by demodulating a mask symbol without using a long code group identification short code. As a result, the hardware scale can be reduced, and the initial synchronization time can be reduced.

In the first to eighth embodiments, the case where the CDMA radio communication apparatus is a mobile terminal is described. However, the present invention is applied to a case where the CDMA radio communication apparatus is a non-mobile communication terminal. It can be applied in some cases.

In the first to eighth embodiments, the case where the mask symbol is located at the head of the slot in the frame has been described.
If a mask symbol exists in a slot in a frame, a similar effect can be exerted.

The present invention is not limited to the above-described first to eighth embodiments, but can be implemented with various modifications. Further, the first to eighth embodiments can be implemented in appropriate combinations.

[0130]

As described above, according to the present invention, a position where a mask symbol spread by a long code group identification short code is multiplexed with a mask symbol spread by a short code common to all base stations is patterned to form a long code. When a group identification short code is detected, the pattern is detected to determine a long code phase. This allows
The time required for long code identification can be significantly reduced without increasing the hardware scale.

In the present invention, long code phase information or long code group information is used for mask symbol data. As a result, the time required for long code identification can be significantly reduced. Further, in the present invention, a plurality of mask symbols in one slot are formed using a plurality of short codes common to all base stations, and a long code group is determined from the positional relationship. As a result, the time required for long code identification can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a CDMA wireless communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an initial synchronization unit of the CDMA wireless communication device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a frame format on a transmission side according to the first embodiment of the present invention;

FIG. 4 is a diagram showing a short code correlation power value common to all base stations according to the first embodiment of the present invention.

FIG. 5 is a view for explaining timing for detecting a frame position using a correlation value of a long code group identification short code according to the first embodiment of the present invention;

FIG. 6 is a block diagram illustrating a configuration of an initial synchronization unit of a CDMA wireless communication device according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating a frame format on a transmission side according to a second embodiment of the present invention;

FIG. 8 is a block diagram illustrating a configuration of a long code group identification short code identification unit according to a third embodiment of the present invention.

FIG. 9 is a diagram showing a frame format on a transmission side according to a fourth embodiment of the present invention.

FIG. 10 is a block diagram illustrating a configuration of an initial synchronization unit of a CDMA wireless communication apparatus according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing a frame format on a transmitting side according to a fifth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of an initial synchronization unit of a CDMA wireless communication apparatus according to a sixth embodiment of the present invention.

FIG. 13 is a diagram showing a frame format on the transmission side according to a sixth embodiment of the present invention.

FIG. 14 is a block diagram illustrating a configuration of an initial synchronization unit of a CDMA wireless communication apparatus according to a seventh embodiment of the present invention.

FIG. 15 is a block diagram illustrating a configuration of an initial synchronization unit of a CDMA wireless communication apparatus according to an eighth embodiment of the present invention.

FIG. 16 is a block diagram showing a configuration of an initial synchronization unit of a conventional CDMA wireless communication device.

[Explanation of symbols]

101 Common Short Code Generator 103 Matched Filter 107 Mask Symbol Timing Generator 112 Long Code Group Identification Short Code Generator 113 Pattern Detector 114 Long Code Timing Generator 119 Long Code × Short Code Generator 123 Long Code Phase Detector 124 Buffer Memory 126 Long code group detection unit 127 Long code type detection unit

Claims (1)

[Claims] 1. A frame comprising a plurality of slots, and a first common slot is provided at a predetermined position of each slot.
A CDMA radio communication apparatus for receiving a signal in which a code and one second code selected from a plurality of second codes are arranged, a unit for specifying a slot timing of each slot using the first code; Means for specifying, for each slot, which of the plurality of second codes is the second code arranged in each slot, based on the specified slot timing; Means for specifying the frame timing and specifying the long code group based on the sequence pattern of the second code of the above, and among the plurality of long codes belonging to the specified long code group based on the specified frame timing Means for specifying a long code; and a CDMA radio communication apparatus comprising: