JP2007202199A - Cdma radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the time required for long code identification without increasing the hardware scale. <P>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 in 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 part 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. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  In an asynchronous CDMA cellular radio communication system between base stations using a mobile terminal such as a mobile phone or a car phone, a cell is used for initial synchronization establishment work when the mobile terminal is turned on or cell switching (handover) associated with movement. It is necessary to perform a search.

  This cell search is performed by partially masking the long code among the short code common to each cell used for the downlink control channel signal and the long code unique to each base station, and performing correlation detection with the short code for the masked portion. This is done by detecting the timing of the long code and its type.

  Specifically, in an asynchronous CDMA cellular mobile communication system between base stations, on the transmission side (base station), symbols and cells spread with a short code (CSC) common to each cell as a search code (search code) A mask portion of a long code in which a plurality of symbols spread with a long code group identification short code (GIC) corresponding to a group to which the long code belongs are provided at equal intervals (for example, for each slot) in one frame for each slot Code-multiplexed and transmitted.

  The receiving side (mobile terminal) first detects the slot timing using a short code common to each cell. Thereafter, long code group identification short codes are used to limit long code candidates to be searched, and cell-specific long codes are identified from the long code candidates.

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

  The output of the matched filter 3 is converted into a power value by the power conversion unit 4, and this power value is averaged by the averaging unit 5. The power value of the correlation value required for averaging is stored in the memory 2. In the predetermined period, the maximum value among 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, the correlator 8 sequentially correlates the input signal 20 with the long code group identification short code generated by the long code group identification short code generation unit 12 and the mask symbol timing. The output of each correlator 8 is converted into a power value by the power converter 9, and the power value obtained in a predetermined period is integrated by the integrator 10. Next, the maximum value detection unit 11 detects the maximum value of the integrated power value, and the long code group is identified by the long code group identification short code having the maximum value. The output of the maximum value detection unit 11 is sent to the long code timing control unit 21.

  The input signal 20 is correlated in the correlator 15 between the long code and the short code generated by the long code × short code generator 19. For the long code × short code generated by the long code × short code generating unit 19, the long code timing control unit 21 changes the phase of the long code in units of search codes (for example, in units of slots). The long code is 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 the power converter 16, and the power value obtained in a predetermined period is integrated by the integrator 17. Next, the threshold determination unit 18 determines whether or not the integrated value exceeds the threshold, identifies the long code when the threshold is exceeded 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 long code belonging to the long code group is sequentially changed until the integral value of the correlation values of the short codes common to all base stations exceeds the threshold value. In this way, cell search is performed.

  However, in the initial synchronization unit of the conventional CDMA wireless communication apparatus, the phase differs by the number of slots in the stage of identifying the long code from the long code group. Detection must also be performed. Therefore, there is a problem that a long 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 long code identification time can be shortened, but there is a problem that the hardware scale becomes enormous.

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

  The CDMA wireless communication apparatus of the present invention is composed of a frame composed of a plurality of slots, and a first code common to each slot and one second code selected from the plurality of second codes are arranged at predetermined positions in each slot. A CDMA radio communication apparatus for receiving a received signal, the means for specifying a slot timing of each slot using the first code, and the second code arranged in each slot based on the specified slot timing Based on the means for specifying for each slot whether the code is the plurality of second codes and the sequence pattern of the plurality of second codes specified for each slot, the frame timing is specified and the long code A plurality of members belonging to the specified long code group based on the means for specifying the group and the specified frame timing A configuration that includes means for identifying a long code, from among the RCs.

  According to the present invention, it is possible to significantly reduce the time required for long code identification without increasing the hardware scale.

  The CDMA radio communication apparatus according to the first aspect of the present invention includes means for detecting timing of a mask symbol used in cell search using a long code mask, and means for identifying a long code group at the detected timing And a means for detecting the phase of the long code from the pattern data relating to the mask symbol, and a means for identifying the long code from the identified long code group.

  According to this configuration, since the phase of the long code is detected from the pattern data related to the mask symbol, it is not necessary to detect the phase of the long code by shifting for each symbol, and the long code phase is not required without enormous hardware. Can be detected in a short time.

  The CDMA wireless communication apparatus according to the second aspect of the present invention employs a configuration in which, in the first aspect, the pattern data is pattern data of correlation values.

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

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

  According to these configurations, since it 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 for detecting a timing of a mask symbol used in a cell search using a long code mask, and detecting a phase of a long code from pattern data related to the mask symbol. And a means for identifying the long code.

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

  A CDMA radio communication apparatus according to a sixth aspect of the present invention, in the fifth aspect, employs a configuration in which the pattern data is pattern data at a position where symbols spread by different short codes exist in one slot.

  According to this configuration, since it 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 for detecting a timing of a mask symbol used in a cell search using a long code mask, and identifying a long code group from pattern data related to the mask symbol. 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 long code type can be shortened, so that the initial synchronization time can be further shortened.

  The CDMA radio communication apparatus according to the eighth aspect of the present invention is a means for detecting a timing of a mask symbol used in a cell search using a long code mask, and a means for identifying a long code group at the detected timing And means for detecting the phase of the long code in the detected long code group, and means for identifying the long code from the identified long code group, wherein the means for identifying the long code group comprises mask symbol data A configuration having a memory for holding

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

  The CDMA radio communication apparatus according to the ninth aspect of the present invention includes means for detecting a phase of a long code from a positional relationship of mask symbols used in cell search using a long code mask, and an identified long code group And a means for identifying a long code, and the mask symbol adopts a configuration in which symbols spread by different short codes exist at different positions in 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 shortened.

  A communication terminal apparatus according to a tenth aspect of the present invention employs a configuration including the CDMA wireless communication apparatus according to any one of the first to ninth aspects.

  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 radio communication system according to a twelfth aspect of the present invention employs a configuration including the communication terminal apparatus according to the tenth aspect and a base station apparatus that performs radio communication with the communication terminal apparatus according to the tenth aspect.

  According to these configurations, since the CDMA radio communication apparatus described above is provided, cell search can be performed at high speed in the digital radio communication system.

  In the CDMA radio communication system according to the thirteenth aspect of the present invention, the first mask symbols masked by the long code and spread only by the short code common to all base stations are provided at equal intervals in one frame, and the long code is masked and long. Correlating a transmission means for transmitting a second mask symbol spread only by a code group identification short code to the first mask symbol in accordance with a predetermined pattern, and a received signal and a short code common to all base stations. Means for obtaining a first correlation value; means for detecting the maximum value of the first correlation value to detect timing of the first mask symbol; the second mask symbol; a candidate for a long code group identification short code; Means for obtaining the second correlation value by sequentially taking the correlations of the two and the candidate having the maximum second correlation value as a long code group A long code group is obtained as another short code, a long code head position is detected from a correlation pattern between the second mask symbol and the long code group identification short code, and a long code phase is obtained. Corresponding to the third correlation value exceeding the threshold calculated from the maximum value of the first correlation value, means for obtaining the third correlation value by sequentially taking the correlation between the long code in the long code group and the received signal And a means for identifying the long code as the long code of the base station that transmitted the received signal.

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

  In the CDMA radio communication system according to the fourteenth aspect of the present invention, the first mask symbols masked by the long code and spread by the short code common to all base stations are provided at equal intervals in one frame, the long code is masked, and the long code A transmission means for transmitting a second mask symbol spread by a group identification short code after a predetermined symbol of the first mask symbol in accordance with a predetermined pattern, and a correlation between a received signal and a short code common to all base stations is obtained. Means for obtaining one correlation value; means for detecting the maximum value of the first correlation value to detect the timing of the first mask symbol; and correlation between the second mask symbol and a long code group identification short code candidate Means for sequentially obtaining the second correlation value, and selecting a candidate having the maximum second correlation value as a long code group A long code group is obtained as another short code, a long code head position is detected from a correlation pattern between the second mask symbol and the long code group identification short code, and a long code phase is obtained. Corresponding to the third correlation value exceeding the threshold calculated from the maximum value of the first correlation value, means for obtaining the third correlation value by sequentially taking the correlation between the long code in the long code group and the received signal And a means for identifying the long code as the long code of the base station that transmitted the received signal.

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

  The CDMA radio communication system according to a fifteenth aspect of the present invention is the CDMA radio communication system according to the thirteenth aspect, wherein means for assigning long code phase information to the first mask symbol and spreading with a short code common to all base stations, A configuration further comprises means for demodulating the first mask symbol with a short code common to the stations 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 diffused and transmitted in the mask symbol, the time required for long code identification can be greatly shortened.

  The CDMA radio communication system according to a sixteenth aspect of the present invention is the CDMA wireless communication system according to the thirteenth aspect, wherein means for assigning long code phase information to the second mask symbol and spreading with a long code group identification short code, and the long code group identification The configuration further includes means for demodulating the second mask symbol with a short code to obtain demodulated data, and means for detecting a long code phase from the demodulated data pattern.

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

  A CDMA radio communication system according to a seventeenth aspect of the present invention is the CDMA wireless communication system according to the thirteenth aspect, wherein long code phase information is assigned to the first mask symbol and spread with a short code common to all base stations, and the second mask symbol Means for allocating the long code phase information and spreading with the long code group identification short code, means for demodulating the first mask symbol with a short code common to all base stations and obtaining first demodulated data, Means for demodulating the second mask symbol with a long code group identification short code to obtain second demodulated data; and means for detecting a long code phase from both the first demodulated data pattern and the second demodulated data pattern And the structure which further comprises.

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

  A CDMA radio communication system according to an eighteenth aspect of the present invention is the CDMA wireless communication system according to the thirteenth aspect, wherein a buffer memory that holds the data of the second mask symbol, the second mask symbol that is held in the buffer memory, and the long code Means for performing time-division processing for correlation with the group identification short code.

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

  A CDMA radio communication system according to a nineteenth aspect of the present invention includes means for assigning long code group identification data to a mask symbol masked with a long code, spreading and transmitting with a short code common to all base stations, a received signal, Means for detecting the timing of the mask symbol from a maximum correlation value with a short code common to all base stations; and demodulating the mask symbol with a short code common to all base stations; Means for taking out group identification data and discriminating a long code group and a long code phase from a pattern of the long code group identification data; and a correlation between the received signal and a long code in the long code group at the long code phase The correlation value is the same for all base stations. The long code that exceeds the calculated threshold from Tokodo employs a configuration and means for identifying a long code of the base station which transmitted the received signal.

  According to this configuration, since 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, the initial synchronization time can be shortened.

  The CDMA radio communication system according to the twentieth aspect of the present invention is configured to mask only a long code and spread only with a short code common to all first base stations, and only a short code common to all second base stations. Using the means for transmitting the second mask symbols spread in step 1 at different positions at equal intervals in one frame, and using a matched filter or a sliding correlator, the received signal and the first base station A means for taking a correlation with a short code and detecting a timing of the first mask symbol from a maximum value of the correlation value; and a maximum value of a correlation value between the received signal and the short code common to all the second base stations. From the positional relationship between the maximum values of the correlation values of the short code common to all the first base stations and the short code common to all the second base stations, The correlation between the received signal and the candidate in the long code group is sequentially shifted in phase, and the correlation value is obtained based on the correlation value of the short code common to all base stations. And a means for identifying a long code exceeding a threshold value as a long code of a base station that has 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 greatly shortened.

  A CDMA radio communication system according to a twenty-first aspect of the present invention is the CDMA wireless communication system according to the twentieth aspect, wherein long code phase information is assigned to the first mask symbol and spread only with a short code common to all first base stations, A means for assigning long code phase information to two mask symbols and spreading only with a short code common to all second base stations, using information demodulated from the first mask symbol and information demodulated from the second mask symbol A means for detecting a long code phase, and sequentially taking a correlation between the received signal and a candidate in the long code group with the long code phase, and a correlation value is a correlation value of a short code common to all base stations. Means for identifying a long code exceeding a threshold obtained based on the long code of the base station that has transmitted the received signal; Take the deposition.

  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 shortened.

  A CDMA radio communication system according to a twenty-second aspect of the present invention, in the twentieth aspect, assigns information of a long code type to the first mask symbol and spreads only with a short code common to all the first base stations, Means for allocating the long code type information to the second mask symbol and spreading only with the short code common to all the second base stations; and sharing the first mask symbol and the second mask symbol with all the base stations The long code type information is extracted by demodulating with the short code, and a long code phase is determined from the long code type information pattern, using the long code group information and the long code type information. And a means for determining the type of the long code.

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

  The inventor paid attention to the correlation power value pattern and the spread data pattern on the receiving side, and found that the long code phase can be detected using these patterns, and has come 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 the present embodiment, a CDMA mobile communication system that detects the phase of a long code from a multiplexed pattern of mask symbols spread by two short codes will be described.

  FIG. 1 is a block diagram showing a schematic configuration of a CDMA wireless communication system. In this system, on the base station side, a transmission signal is frame-configured according to a predetermined frame format by the frame configuration unit 201 and transmitted from the antenna 203 via the radio unit 202. On the other hand, on the mobile terminal side, a signal is received by the antenna 204 and sent to the initial synchronization unit 206 via the radio unit 205. In FIG. 1, the processing units unique to CDMA in the base station and the mobile terminal are the same as usual, and are omitted.

  FIG. 2 is a block diagram showing a configuration of an initial synchronization unit of the CDMA radio communication apparatus (mobile terminal) according to the first embodiment of the present invention. In FIG. 2, the signal transmitted from the base station is received by the mobile terminal and becomes the input signal 120. The input signal 120 is correlated with the short code common to all base stations generated by the short code generator 101 common to all base stations in the matched filter 103.

  The output of the matched filter 103 is converted into a power value by the power conversion unit 104, and the power value is averaged by the averaging unit 105. The power value of the correlation value required for averaging, for example, data of the number of chips for one slot is stored in the memory 102. In the predetermined period, the maximum value among 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. As a result, the slot timing is detected, and the symbol timing is also detected at the same time. In this way, the mask symbol timing process 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 the power conversion unit 109, and the power value obtained in a predetermined period is integrated by the integration unit 110. Next, the maximum value detection unit 111 detects the maximum value of the integrated power value, and the long code group is identified by the long code group identification short code of the maximum value. Note that the output of the maximum value detection unit 111 is sent to the long code × short code generation unit 119.

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

  The input signal 120 is correlated with the long code × short code generated by the long code × short code generation unit 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 in a predetermined period is integrated by the integration unit 117. Next, the threshold value determination unit 118 identifies a long code exceeding the threshold value among the maximum values detected by the maximum value detection unit 106 as the long code of the base station. This completes the long code identification process.

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

  An operation in the initial synchronization unit 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, the transmission side (base station) performs frame configuration so as to provide mask symbols in which long codes are masked 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 the slot will be described.

  In the frame configuration shown in FIG. 3, the long code is repeated in the frame period, and the head of the long code is the head of the frame. Further, in this frame configuration, with respect to the mask symbol, data spread only by a short code common to all base stations and data spread only by a long code group identification short code are multiplexed. On the other hand, other symbols are spread twice with a short code common to all base stations and a long code unique to the base station. However, since the data spread only by the long code group identification short code is multiplexed at a predetermined position in the symbol spread by the short code common to all base stations, it is a symbol spread by 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 subjected to correlation processing with the short code common to all base stations by the matched filter 103, and the correlation value is output at the chip speed. 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times.

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

  Next, in the long code group identification step, the long code group identification short code generation unit 112 sequentially generates all long code group identification short codes in units of one frame at the detected mask symbol timing, and generates a correlator. At 108, a correlation is established between the long code group identification short code and the mask symbol in the input signal. The integrating unit 110 integrates the correlation power value between the mask symbol for one frame and the long code group identification short code. Maximum value detection section 111 identifies the long code group identification short code having the maximum 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 first slot of the frame is detected from the pattern of the correlation value (power value) of the mask symbol in one frame. In the frame on the transmission side, the portion where the long code group identification short code is multiplexed with the mask symbol has a pattern as shown in FIG. The multiplexing pattern in this example is “1111011110101100”. FIG. 5 shows a state in which only mask symbols are extracted and other symbols are omitted.

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

  Next, in the long code identification step, a 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. Correlator 115 then correlates the replica code with symbols other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the power value is integrated by the integration unit 117 over a specified number of symbols. In the threshold value determination unit 118, the threshold value calculated from the maximum value of the correlation power value of the short code common to all base stations detected by the maximum value detection unit 106 is compared with the integrated value, and the integrated value exceeds the threshold value. The long code is identified as the long code of the base station.

  In the conventional method, in the long code identification step, the phase of each long code must be shifted by the slot unit, and the correlation value of the long code must be obtained by the number of slots. On the other hand, according to the method of the present embodiment, it is not necessary to take the correlation value of long codes by the number of slots for one long code. Therefore, when the number of slots is N, the method of the present embodiment takes 1 / N times the time required for the long code identification process as compared with the conventional method.

  Thus, according to the present embodiment, on the transmission side, a mask code diffused with a long code group identification short code is added to a predetermined pattern on a long code mask symbol spread with a short code common to all base stations in one frame. In the long code group identification short code identification process, the pattern is detected to detect the phase of the long code, for example, the head position of the long code is detected. As a result, the time required for the initial synchronization can be greatly shortened.

(Second Embodiment)
In the present embodiment, a CDMA wireless communication apparatus that detects the phase of a long code from pattern data spread with a short code and / or a long code group identification short code common to all base stations will be described.

  FIG. 6 is a block diagram showing a configuration of an initial synchronization unit of the CDMA radio communication apparatus (mobile terminal) according to the present embodiment. In FIG. 6, the same parts as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  The output of the matched filter 103 in the mask symbol timing detection step is sent to the data demodulator 121, from which data included in the mask symbol spread with a short code common to all base stations is extracted. 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 demodulator 122, and the data included in the mask symbol spread by the long code group identification short code is extracted from the output. The extracted data is sent to the long code phase detection unit 123.

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

  The operation of the initial synchronization unit of the CDMA radio communication apparatus having the above configuration will be described. First, on the transmission side (base station), as shown in FIG. 7, a frame configuration is performed so as to provide a mask symbol in which a long code is masked 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 the slot will be described.

  In the frame configuration shown in FIG. 7, the long code is repeated at the frame period, and the head of the long code is the head of the frame. Further, in this frame configuration, with respect to the mask symbol, data spread only by a short code common to all base stations and data spread only by a long code group identification short code are multiplexed. On the other hand, other symbols are spread twice 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 and / or a long code group identification short code common to all base stations. Long code phase information (pattern data) is included in a closed state in a frame, and the same information is transmitted every frame.

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

  First, in the long code timing detection step, the received data (input signal 120) is subjected to correlation processing with the short code common to all base stations by the matched filter 103, and the correlation value is output at the chip speed. 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times.

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

  Further, the data demodulator 121 demodulates the correlation output for the short code common to all base stations from the matched filter 103 only for the mask symbol, and extracts the 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 pattern by detecting the extracted data pattern. Thereby, long code timing is obtained.

  Next, in the long code group identification step, the long code group identification short code generation unit 112 sequentially changes and generates all long code group identification short codes at the detected mask symbol timing, and the correlator 108 generates the long code group identification short code. Correlate the code group identification short code with the mask symbol in the input signal. The integration unit 110 integrates the correlation power value between the mask symbol and the long code group identification short code by the specified number of symbols. Maximum value detection section 111 identifies the long code group identification short code having the maximum 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 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. Correlator 115 then correlates the replica code with symbols other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the power value is integrated by the integration unit 117 over a specified number of symbols. In the threshold value determination unit 118, the threshold value calculated from the maximum value of the correlation power value of the short code common to all base stations detected by the maximum value detection unit 106 is compared with the integrated value, and the integrated value exceeds the threshold value. The long code is identified as the long code of the base station.

  In the above method, after identifying the long code group identification short code, the data demodulator 122 is used to extract the data spread by the long code group identification short code, and the long code phase is detected from the pattern. May be.

  As described above, according to the present embodiment, on the transmission side, pattern data for long code phase detection is assigned to a long code mask symbol in one frame, and a short code and / or a long code common to all base stations is allocated. Spread by the group identification short code and transmit, and the initial synchronization unit on the receiving side extracts the pattern data from the output of the matched filter and / or the correlator of the long code group identification short code, and the long code phase from the pattern Is detected. As a result, it is not necessary to take the correlation value of the long code by the number of slots for one long code, and the time required for the initial synchronization can be greatly shortened.

(Third embodiment)
In the present embodiment, a CDMA radio communication apparatus will be described in which 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 a time division manner within one slot.

  FIG. 8 is a block diagram showing the configuration of the long code group identification short code identification unit of the CDMA radio communication apparatus according to the present embodiment. In FIG. 8, the same parts as those in FIG. 6 are denoted by the same reference numerals as those in FIG. The buffer memory 124 illustrated in FIG. 8 holds mask symbol data of the input signal 120.

  The operation of the long code group identification short code identification unit having the above configuration will be described. Of the input signal 120, only mask symbol data is held in the buffer memory 124. In this case, since it is only necessary to obtain a correlation between the long symbol group identification short code and the mask symbol, one symbol time is sufficient 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 receiving side initial synchronization unit holds the mask symbol data in the buffer memory, and performs the correlation process of the long code group identification short code in one slot in a time division manner. In addition, the time required for long code group identification and short code identification can be greatly reduced.

(Fourth embodiment)
In this embodiment, a CDMA radio communication apparatus that performs communication in a frame configuration 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 explain.

  FIG. 9 is a diagram showing a frame format used in wireless communication in the present embodiment. On the transmission side, the frame format shown in FIG. In this frame configuration, two mask symbols are provided in one slot, and symbols spread with a short code common to all base stations and symbols spread with a long code group identification short code are assigned to each mask symbol. In FIG. 9, for simplification of description, the two mask symbols are continuously provided in one slot.

  On the receiving side, in the long code group identification step, the input signal and the long code group identification short code are received 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. A long code group identification short code is identified.

  In this 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 becomes difficult to be affected by noise and fading. In the present embodiment, a case has been described in which the mask symbol spread with the long code group identification short code is one symbol after the mask symbol spread with 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, the same as above Cell search can be performed.

  As described above, according to the present embodiment, on the transmitting side of the wireless communication system, the mask symbol spread with the short code common to all base stations and the mask symbol spread with the long code group identification short code are divided into two. Since the transmission is performed separately, the correlation value and the correlation power value increase in the initial synchronization unit on the reception side. As a result, in this system, initial synchronization can be reliably achieved in a state resistant to noise and the like.

(Fifth embodiment)
In this embodiment, a CDMA wireless communication apparatus that detects a long code group and a phase of a long code from pattern data spread with a short code common to all base stations will be described.

  FIG. 10 is a block diagram showing a configuration of an initial synchronization unit 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. The initial synchronization unit shown in FIG. 10 has a configuration excluding the configuration related to the long code group identification step in the initial synchronization unit shown in FIG. That is, the initial synchronization unit shown in FIG. 10 includes the correlator 108, the power conversion unit 109, the integration unit 110, the maximum value detection unit 111, the long code group identification short code generation unit 112, and the data from the initial synchronization unit shown in FIG. Except for the demodulator 122, a long code group detector 126 is provided instead of the long code phase detector 123. The long code group detection unit 126 detects a long code group and a long code phase 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 unit of the CDMA radio communication apparatus having the above configuration will be described. First, on the transmission side, as shown in FIG. 11, a frame configuration is performed so that mask symbols with a long code masked for each slot are provided at equal intervals for the transmission signal. Here, in order to simplify the description, a case where a mask symbol is provided at the head of the slot will be described.

  In the frame configuration shown in FIG. 11, the long code is repeated at the 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 spread twice with a short code common to all base stations and a long code unique to the base station. The long code group identification data is included in a closed state within a frame, and is transmitted repeatedly every frame.

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

  Next, in the long code group identification step, the data demodulating unit 121 demodulates the data for only the mask symbol in the correlation output from the matched filter 103, and extracts the pattern of the long code group identification data. Next, a long code group is identified and a long code phase is detected by matching the pattern of the extracted long code group identification data with a pattern 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, a 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. Correlator 115 then correlates the replica code with symbols other than the mask symbol. The correlation value is converted into a power value by the power conversion unit 116, and the power value is integrated by the integration unit 117 over a specified number of symbols. In the threshold value determination unit 118, the threshold value calculated from the maximum value of the correlation power value of the short code common to all base stations detected by the maximum value detection unit 106 is compared with the integrated value, and the integrated value exceeds the threshold value. The long code is identified as the long code of the base station.

  As described above, according to the present embodiment, the transmitting side transmits a long code mask symbol obtained by spreading pattern data for detecting a long code group with a short code common to all base stations, and an initial synchronization unit on the receiving side Then, pattern data is extracted from the output of the matched filter, and identification of a long code group and detection of a long code phase are performed from the pattern data. As a result, the time required for the initial synchronization can be greatly shortened, and the hardware can be reduced.

(Sixth embodiment)
In the present embodiment, a CDMA wireless communication apparatus that identifies 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 radio communication apparatus (mobile terminal) according to the present embodiment. In FIG. 12, the same parts as those in FIG. 10 are denoted by the same reference numerals as those in FIG. 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 excluded from the initial synchronization unit shown in FIG. In this initial synchronization unit, the long code group detection unit 126 identifies a long code group from the output of the maximum value detection unit 106, that is, the maximum value of the short code common to all two base stations.

  The operation of the initial synchronization unit of the CDMA radio communication apparatus having the above configuration will be described. On the transmission side, as shown in FIG. 13, the frame configuration is performed so as to provide two mask symbols with a long code masked in one slot. Here, for simplicity of 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 a short code common to all the first base stations is assigned to the mask symbol at the head of the slot, and a symbol spread with a short code common to all the second 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 detection process, the input signal 120 is matched with the first short code common to all first base stations generated by the common short code generator 101 by the matched filter 103. Correlation processing is performed. The correlation output data 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times. The maximum value of the averaged correlation power value is detected by the maximum value detection unit 106, and based on this maximum value, the mask symbol timing generation unit 107 detects the mask symbol timing, that is, the slot timing.

  Next, in the long code group identification step, the matched filter 103 correlates the input signal 120 with the short code common to all the second base stations generated by the common short code generator 101. The correlation output data 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times. The maximum value of the averaged power value is detected by the maximum value detection unit 106. This maximum value and the previously detected slot timing are sent to the long code group detection unit 126. The long code group detection unit 126 uses the previously detected slot timing and the timing at which the maximum value is obtained, to determine the positional relationship of the mask symbols in the slot (the symbol having the maximum correlation value in the slot). The long code group corresponding to the positional relationship is identified.

  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. Further, until the threshold value determination unit 118 obtains a long code whose integrated value of the correlation power value exceeds the threshold value, the long code is sequentially changed from the candidates and the correlation process is performed. The long code whose integrated 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 this embodiment, two mask symbols spread with a short code common to all base stations are transmitted on the transmission side, and the long code group identification short code is not used in the initial synchronization unit on the reception side. In addition, a long code group is detected from the positional relationship between the two mask symbols. Thereby, the hardware scale can be reduced and the initial synchronization time can be shortened.

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

(Seventh embodiment)
In the present embodiment, a CDMA wireless communication apparatus that detects a long code phase from a long code phase information pattern will be described. FIG. 14 is a block diagram showing a configuration of an initial synchronization unit of the CDMA radio communication apparatus (mobile terminal) according to the present embodiment. 14, the same parts as those in FIG. 10 are denoted by the same reference numerals as those in FIG. In the CDMA radio communication apparatus shown in FIG. 14, the long code phase detection unit 123 detects the long code phase using the data extracted by the data demodulation unit 121.

  The operation of the initial synchronization unit of the CDMA radio communication apparatus having the above configuration will be described. On the transmitting side, as in the sixth embodiment, as shown in FIG. 13, the frame configuration is performed so that two mask symbols in which a long code is masked are provided in one slot. Here, for simplicity of 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 a short code common to all the first base stations is assigned to the mask symbol at the head of the slot, and a symbol spread with a short code common to all the second 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 that gives long code phase information. Further, the positional relationship (pattern) of 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 detection step, the input signal 120 is matched with the first short code common to all base stations generated by the common short code generator 101 by the matched filter 103. Correlation processing is performed. The correlation output data 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times. The maximum value of the averaged correlation power value is detected by the maximum value detection unit 106, and based on this maximum value, the mask symbol timing generation unit 107 detects the mask symbol timing, that is, the slot timing.

  Next, in the long code group identification step, the matched filter 103 correlates the input signal 120 with the short code common to all the second base stations generated by the common short code generator 101. The correlation output data 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 added by a plurality of slots by the averaging unit 105 and averaged for a specified number of times. The maximum value of the averaged power value is detected by the maximum value detection unit 106. This maximum value and the previously detected slot timing are sent to the long code group detection unit 126. The long code group detection unit 126 uses the previously detected slot timing and the timing at which the maximum value is obtained, to determine the positional relationship of the mask symbols in the slot (the symbol having the maximum correlation value in the slot). The long code group corresponding to the positional relationship is identified.

  In addition, the data demodulating unit 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 detected and the long code is sequentially changed to perform correlation processing with the input signal to obtain the correlation power value. , The correlation power value is integrated. Until the threshold value determination unit 118 obtains a long code whose integrated value of the correlation power value exceeds the threshold value, the long code is sequentially changed from the candidates and the correlation process is performed. A long code whose integrated value exceeds the threshold is identified as the long code of the base station.

  As described above, according to the present embodiment, on the transmitting side, two mask symbols having long code phase information spread with a short code common to all base stations are transmitted. Without using the identification short code, the long code group is detected from the positional relationship between the two mask symbols, and the long code phase is detected from the long code phase information. Thereby, the hardware scale can be reduced and the initial synchronization time can be shortened.

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

  The operation of the initial synchronization unit of the CDMA radio communication apparatus having the above configuration will be described. On the transmitting side, as in the sixth embodiment, as shown in FIG. 13, the frame configuration is performed so that two mask symbols in which a long code is masked are provided in one slot. Here, for simplicity of 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 a short code common to all the first base stations is assigned to the mask symbol at the head of the slot, and a symbol spread with a short code common to all the second base stations is assigned to the remaining mask symbols. assign. In this case, the data spreading with the short code common to all the first and second base stations includes a pattern that gives the type of the long code. Further, the positional relationship (pattern) of 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, as in the sixth embodiment, slot timing is detected using a short code common to all first base stations and a short code common to all second base stations. A long code group is identified from the positional relationship between two mask symbols in the slot.

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

  Thus, according to the present embodiment, the transmitting side transmits two mask symbols having long code type information spread with a short code common to all base stations, and the initial synchronization unit on the receiving side transmits a long code group. Without using the identification short code, the mask symbol is demodulated to detect the type of long code and the long code phase. Thereby, the hardware scale can be reduced and the initial synchronization time can be shortened.

  In the first to eighth embodiments, the case where the CDMA wireless communication apparatus is a mobile terminal has been described. However, the present invention is applied to a case where the CDMA wireless communication apparatus is a non-mobile communication terminal. Can also be applied.

  In the first to eighth embodiments, the case where the mask symbol is located at the beginning of the slot in the frame has been described. However, in the present invention, if the mask symbol exists in the slot in the frame, The same effect can be exhibited.

  The present invention is not limited to the first to eighth embodiments, and can be implemented with various modifications. Moreover, the said 1st-8th embodiment can be implemented in combination as appropriate.

  As described above, in the present invention, long code group identification short code detection is performed by patterning a position where a mask symbol spread with a long code group identification short code is multiplexed with a mask symbol spread with a short code common to all base stations. Sometimes the pattern is detected to determine the long code phase. As a result, the time required for long code identification can be significantly shortened without increasing the hardware scale.

  In the present invention, long code phase information or long code group information is used for mask symbol data. Thereby, 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 made using a short code common to all the plurality of base stations, and a long code group is discriminated from the positional relationship. Thereby, the time required for long code identification can be significantly reduced.

1 is a block diagram showing a schematic configuration of a CDMA radio communication system according to a first embodiment of the present invention. The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 1st Embodiment of this invention. The figure which shows the frame format by the side of the transmission in the 1st Embodiment of this invention The figure which shows the short code correlation electric power value common to all the base stations in the 1st Embodiment of this invention The figure for demonstrating the timing for the frame position detection using the correlation value of the long code group identification short code in the 1st Embodiment of this invention The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the frame format by the side of the transmission in the 2nd Embodiment of this invention. The block diagram which shows the structure of the long code group identification short code identification part in the 3rd Embodiment of this invention. The figure which shows the frame format by the side of the transmission in the 4th Embodiment of this invention. The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 5th Embodiment of this invention. The figure which shows the frame format by the side of the transmission in the 5th Embodiment of this invention The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 6th Embodiment of this invention. The figure which shows the frame format by the side of the transmission in the 6th Embodiment of this invention The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 7th Embodiment of this invention. The block diagram which shows the structure of the initial stage synchronization part of the CDMA radio | wireless communication apparatus which concerns on the 8th Embodiment of this invention. A block diagram showing a configuration of an initial synchronization unit of a conventional CDMA wireless communication apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Common short code generation part 103 Matched filter 107 Mask symbol timing generation part 112 Long code group identification short code generation part 113 Pattern detection part 114 Long code timing generation part 119 Long code x short code generation part 123 Long code phase detection part 124 Buffer Memory 126 Long code group detection unit 127 Long code type detection unit

Claims (1)

CDMA wireless communication configured to receive a signal composed of a frame made up of a plurality of slots and in which a first code common to each slot and a second code selected from the plurality of second codes are arranged at predetermined positions in each slot A device,
Means for identifying slot timing of each slot using the first code;
Means for identifying for each slot which of the plurality of second codes is the second code arranged in each slot based on the identified slot timing;
Means for specifying a frame timing and a long code group based on a sequence pattern of a plurality of second codes specified for each slot;
Means for identifying a long code from among a plurality of long codes belonging to the identified long code group based on the identified frame timing;
A CDMA wireless communication apparatus comprising:

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