JP2007158714A - Sttd application determination method and mobile communication terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an STTD application determination method capable of reducing a hardware scale, even when transmission diversity is applied, and shortening processing time by starting processings simultaneously with the identification of a scrambling code, and to provide a mobile communication terminal that uses the STTD application determination method. <P>SOLUTION: With respect to the scrambling code identification processing (step S140) of a base station by the third step of a 3-stage cell search method, the output of transmission signals from a base station second transmission antenna is measured by the received field strength of a common pilot channel CPICH, and STTD application determination processing (step S150) for determining the application/non-application of STTD of a first common control physical channel P-CCPCH is performed by parallel processing, on the basis of the measured result. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a spread spectrum communication system, particularly a wireless communication system using a W-CDMA system, and relates to a STTD application determination method and a mobile communication terminal using the STTD application determination method.

  A wireless communication system of W-CDMA (Wideband Code Division Multiple Access) system using a direct spread spectrum spread communication technique is resistant to multipath fading, can speed up data communication, and has good communication quality. Because of its high frequency utilization efficiency, it has been standardized as a global standard for third-generation mobile communication by 3GPP (3rd Generation Partnership Project), which is a standard organization for third-generation mobile communication systems. This W-CDMA wireless communication system has been put into practical use as a third generation mobile phone service in Japan.

  Since a wireless communication system using a spread spectrum communication system such as the W-CDMA system is an asynchronous system between base stations, a mobile station (mobile communication terminal) uses a cell at the time of initial synchronization when power is turned on or a cell associated with movement. At the time of switching (handover) or the like, a cell search process for establishing synchronization with a cell, that is, a base station is performed.

  In this cell search process, detection of the start timing of a downlink frame from the base station and identification of a scrambling code assigned to the base station are performed. There are 512 types of scrambling codes assigned to the base station, and each type is classified into 64 types of scrambling code groups (Scrambling Code Groups). This scrambling code group is described in detail in 3GPP standard TS25.213 5.2.2 “Scrambling code”.

  In the W-CDMA wireless communication system as the third-generation mobile communication described above, a three-stage cell search method is used in order to realize high-speed cell search in the inter-base station asynchronous mode.

  In this three-step cell search method, the mobile station first uses the first synchronization channel P-SCH (Primary Synchronization Channel) as the first step to start the slot head of the received signal (received data) from the base station. Synchronize with timing. The first synchronization channel P-SCH is used by the base station by inserting it at the head of each slot of the downlink frame. The first synchronization code PSC (consisting of a short period code common to all base stations) Primary Synchronization Code). As a process of the first step, the mobile station sequentially shifts the phase of the first synchronization code PSC with respect to the reception signal (reception data) including the first synchronization channel P-SCH. Is obtained, and the timing of the correlation peak is obtained to obtain the slot head timing of the downlink frame from the base station.

  Next, as a second step, the mobile station uses the second synchronization channel S-SCH (Secondary Synchronization Channel) to synchronize the frame head timing and identify the scrambling code group including the scrambling code. Do. This second synchronization channel S-SCH is transmitted in synchronization with the first one symbol period of each slot of the downlink frame, and is spread with a second synchronization code SSC (Secondary Synchronization Code) that is different for each slot. Repeated every frame. The second synchronization code SSC is composed of 16 different short-cycle codes SSC1 to SSC16. Specifically, when the number of slots in one frame is 15, the above-described 64 types of scrambling code groups are represented by combinations of 15 types of second synchronization codes SSC for one frame.

  In accordance with the slot head timing obtained in the first step described above, the mobile station provides 15 types of second synchronization codes corresponding to the head 1 symbol of each slot and scrambling code groups 1 to 64 in one frame. A standard according to 3GPP is obtained by performing correlation processing for each cycle of the scrambling code groups 1 to 64 with each combination of SSC1 to SSC16 while circulating the first slot of the combination one cycle at a time, and obtaining the timing of the correlation peak. The sequence specified in the standard TS25.213 5.2.3 “Synchronisation codes” is searched to obtain the identification of the scrambling code group and the frame head timing.

  In addition, as a third step, the mobile station determines the eight types of scrambling code groups assigned to the scrambling code group identified in the second step according to the frame head timing obtained in the second step. By performing a correlation operation between each scrambling code and a first common pilot channel P-CPICH (Primary Common Pilot Channel) to which a different scrambling code is applied for each base station, the base station currently searched for is calculated. Get a scrambling code. Further, the mobile station demodulates the first common control channel P-CCPCH (Primary Common Control Physical Channel) with the acquired scrambling code and confirms its cyclic redundancy check CRC (Cyclic Redundancy Check), thereby performing the search. Confirm the scrambling code of the base station.

  On the other hand, in the downlink from the base station, there is a transmission diversity function for transmitting a transmission signal to the same communicator using two antennas (base station first transmission antenna and base station second transmission antenna). It has been standardized.

  As this transmission diversity, STTD (Space Time block coding based Transmit antenna Diversity), TSTD (Time Switched Transmit Diversity), and a closed loop mode method using feedback information from a mobile station have been standardized. Yes.

  STTD encodes the same data from a base station and transmits transmission signals simultaneously from two transmission antennas. The standard TS35.211 5.3.1.1.1.1 “Space time block coding based on 3GPP is used. This is described in detail in “transmit antenna diversity (STTD)”. TSTD is a transmission signal that is transmitted from a base station by switching a transmission antenna for each slot. The TSTD conforms to TS 25.211 5.3.1.2 “Time Switched Transmit Diversity for SCH (TSTD)”. It has been explained in detail.

  The downlink physical channels to which each is applied are defined in the standard TS25.211 5.3.1 “Downlink transmit diversity”, and an outline thereof is shown in FIG.

  FIG. 11 is a table summarizing the application of transmit diversity modes for downlink physical channel types.

  The physical channel type “SCH” in the table means both the first synchronization channel P-SCH and the second synchronization channel S-SCH. In the table, a physical channel to which “X” is attached indicates that the physical channel is applicable in the open loop mode TSTD, STTD, or closed loop mode. On the other hand, a physical channel with “-” is a physical channel to which the TSTD or STTD in the open loop mode or the closed loop mode is not applied.

  For example, in the open loop mode, the synchronization channel SCH can be applied with TSTD, but STTD cannot be applied. The first common control physical channel P-CCPCH, the second common control physical channel S-CCPCH, and the dedicated physical channel DPCH (Dedicated Physical Channel), Paging Indication Channel PICH (Paging Indication CHannel), Downlink Common Physical Channel (Physical Downlink Shared Channel), Acquisition Indication Channel AICH (Acquisition Indicator Channel), and Common Packet Channel State Indication Channel CSICH (Common Packet Channel) As for (Status Indicator Channel), STTD is applicable and TSTD is not applicable.

  In addition, STTD is applied or not applied to the first common control physical channel P-CCPCH as described in 3GPP standard TS25.211 5.3.3.1 “Secondary CCPCH structure with STTD encoding”. This is determined depending on whether it is indicated by the message, the synchronization channel SCH is demodulated, or both are used.

  As a matter of course, since the upper layer message is not received in the initial cell search process immediately after the power is turned on, STTD application / non-application when demodulating the first common control physical channel P-CCPCH in the third step is performed. Is determined by a method using the demodulation result of the synchronization channel SCH.

  When transmission diversity is applied, different common pilot channels CPICH are transmitted from the base station first transmission antenna and the base station second transmission antenna in the downlink. This is described in the 3GPP standard TS25.211 5.3.3.1 “Common Pilot Channel (CPICH)”. According to this standard, patterns that are orthogonal to each other are multiplied as data, and in a broad sense, it is similar to orthogonal transmission diversity (OTD).

  By the way, when the transmission diversity function is implemented in the base station, the performance can be improved, while the base station installation requires costs such as two transmission antennas in the base station. Therefore, in the mobile communication system, the transmission diversity function is not necessarily implemented in all the base stations, and a base station that is implemented and a base station that is not implemented are mixed.

  In the above three-stage cell search method, in the final stage of the third step, it is necessary to demodulate the first common control physical channel P-CCPCH. Regarding STTD application / non-application of the first common control physical channel P-CCPCH Since the upper layer message is not received in the initial cell search process immediately after the power is turned on, the standard needs to know from demodulating data (synchronization information) modulated on the synchronization channel SCH.

Next, the configuration of a receiving apparatus (that is, a mobile communication terminal supports) that receives a signal transmitted from a base station in which a conventional transmission diversity function is implemented will be described.
FIG. 12 is an explanatory diagram of a SCH demodulation method by a conventional receiving apparatus.
In FIG. 12, the receiving apparatus will be described as adopting a general TSTD demodulation method.

  The receiving apparatus 100 includes pilot channel receiving units 110 and 120, a synchronization channel receiving unit (SCH receiving unit) 130, a selecting unit 140, a control unit 150, and a complex conjugate arithmetic unit (Phase sign Converter) 160. It is prepared for.

  The receiving apparatus 100 is provided with a number of pilot channel receiving units (this pilot channel corresponds to the above-described common pilot channel CPICH) corresponding to the transmission antennas of the transmitting apparatus provided in the base station. Two pilot channel receivers 110 and 120 are provided corresponding to the two transmission antennas provided in the standardized base station transmission apparatus.

  Each pilot channel receiving unit 110, 120 includes despreading units 112, 122 and phase estimation units 114, 124. Receiving signals (in this case, baseband signals) of transmission signals from the base station first transmission antenna and the base station second transmission antenna of the base station are input to the pilot channel reception units 110 and 120.

  In first pilot channel receiving section 110, despreading section 112 performs complex despreading by applying the pre-determined scrambling code obtained in the third step to this received signal. Here, since it is a common pilot channel CPICH, channelization code No. Is “0”, so there is no need to use it. The despreading unit 112 outputs a signal obtained by integrating one symbol period after despreading.

  The phase estimation unit (propagation path estimation unit) 114 applies to the base station first transmission antenna and the base station second transmission antenna with respect to the signal obtained by integrating the above-described one symbol section output from the despreading unit 112. After multiplying the assigned symbol pattern by the symbol pattern assigned to the first transmitting antenna of the base station, integration processing (average) is performed over several symbols (even number symbols are desirable to maintain orthogonality between antennas). Process). For the symbol patterns assigned to the base station first transmission antenna and the base station second transmission antenna, the 3GPP standard TS25.211 5.3.3.1 “Common Pilot Channel (CPICH)” described above is used. Explained.

  Then, the phase estimation unit 114 analyzes the integration process result (that is, the averaging process result), and estimates the phase (propagation path) of the signal transmitted from the base station first transmission antenna (propagation path). (Estimated value) is output.

  Similarly, in the second pilot channel receiving unit 120, the despreading unit 122 performs complex despreading by applying the pre-determined scrambling code obtained in the third step to the received signal. Again, since the common pilot channel CPICH is used, the channelization code No. Need not be used because it is “0”. The despreading unit 122 outputs a signal obtained by integrating one symbol period after despreading.

  The phase estimator 124 uses the symbol pattern assigned to each of the base station first transmission antenna and the base station second transmission antenna for the signal obtained by integrating the one symbol period output from the despreading unit 122. In this case, after multiplying the symbol pattern assigned to the second transmission antenna of the base station in this case, integration processing (averaging processing) is performed over several symbols (even number symbols are desirable for maintaining orthogonality between antennas). I do.

  Then, the phase estimation unit 124 analyzes the integration processing result (that is, the averaging processing result) to estimate the phase (propagation path) of the signal transmitted from the base station second transmission antenna (propagation path). (Estimated value) is output.

  The control unit 150 synchronizes with the reference time of the base station and outputs a selection control signal for selecting the outputs of the pilot channel receiving units 110 and 120 in units of time switching periods of the base station first and second transmission antennas. appear.

  The selector 140 receives the phase estimation value supplied from each of the pilot channel receivers 110 and 120, and is output from the corresponding pilot channel receivers 110 and 120 based on the selection control signal supplied from the controller 150. The phase estimation value is selectively output to the complex conjugate calculation unit 160.

  The synchronization channel receiver (SCH receiver) 130 includes a despreader 132 and a multiplier 134.

  In synchronization channel receiving section 130, despreading section 132 receives received signals of transmission signals from the base station first transmission antenna and the base station second transmission antenna of the base station. The despreading unit 132 performs orthogonal despreading on the received signal using the first synchronization code PSC.

  In this case, according to the 3GPP specification, the scrambling code of the base station of the synchronization channel portion (SCH portion) of the received signal is masked, and the channelization code is not used. You only need to multiply the PSC.

  The despreading unit 132 outputs a signal obtained by integrating one symbol period after despreading. When both the first synchronization channel P-SCH and the second synchronization channel S-SCH are used, a signal after adding the in-phase component and the quadrature component as a result of the quadrature despreading is output.

  The phase estimation value by the first pilot channel reception unit 110 or the second pilot channel reception unit 120 selected and output from the selection unit 140 is calculated as a complex conjugate value by the complex conjugate calculation unit 160, and a synchronization channel reception unit is obtained. 130. In the synchronization channel receiving unit 130, the output of the despreading unit 132 and the output of the complex conjugate calculation unit 160 are multiplied by the multiplication unit 134 and output. With this multiplication processing, the receiving apparatus 100 realizes synchronous detection of the transmission signal from the base station.

  Here, based on the clock information synchronized with the reference time of the base station, the control unit 150 passes the selection channel 140 from the pilot channel reception units 110 and 120 to the synchronization channel reception unit 130 as a traffic channel receiver. Selectively providing a phase estimate. That is, it is assumed that the mobile station has a known transmission diversity switching pattern and period by the base station, which is standardized by 3GPP.

  In the conventional receiving apparatus 100, after performing an averaging process using the demodulation result of the synchronization channel SCH obtained by the above-described processing, the data (synchronization information) on which the synchronization channel SCH is superimposed is determined. The STTD application / non-application of the first common control physical channel P-CCPCH is determined.

  The conventional STTD application determination system as described above is shown in “Time Switching Transmission Diversity Device and Method for Mobile Communication System” described in Japanese Translation of PCT International Publication No. 2000-514992. In the description of the publication, it is described that OTD is used as a pilot channel, but the same operation can be realized even when a pattern orthogonal to data is multiplied instead of OTD.

Special Table 2000-514992

  In the process of the third step of the above-described three-stage cell search method, the first common control physical channel P-CCPCH is demodulated and the cyclic redundancy check CRC is confirmed, so that the currently searched base station (cell) It is necessary to confirm the scrambling code.

  However, regarding the STTD application / non-application of the first common control physical channel P-CCPCH in the downlink from the base station, since the upper layer message is not received in the initial cell search process immediately after the power is turned on, it is synchronized with the standard. By demodulating the data modulated on the service channel SCH, it is possible to determine whether STTD is applied or not applied to the first common control physical channel P-CCPCH.

  Therefore, in order to demodulate the data modulated on the synchronization channel SCH, scrambling of the eight types of base stations assigned to the scrambling code group obtained in the second step of the three-stage cell search method. It is necessary to perform a process of obtaining a scrambling code of the base station by performing a correlation calculation between the code and the downlink first common pilot channel P-CPICH from the base station.

  Therefore, in order to obtain STTD application / non-application information regarding the first common control physical channel P-CCPCH, it is necessary to perform a process of demodulating data (synchronization information) modulated on the synchronization channel SCH. There is a problem that it takes time to demodulate the data modulated on the synchronization channel SCH.

  The present invention has been made in view of the above-described problems, and can reduce the processing time required for cell search and the like by reducing the hardware scale and performing processing simultaneously with identification of the scrambling code. An object of the present invention is to provide an STTD application determination method that can be used and a mobile communication terminal that uses the STTD application determination method.

  In order to solve the above-described problem, a mobile communication terminal using the STTD application determination method of the present invention measures the reception electric field strength of the common pilot channel CPICH from the base station second transmission antenna by the measurement unit, and determines the determination unit. By using the measurement value obtained by this measurement means, the presence / absence of transmission from the base station second transmission antenna is determined, and from this determination result, the common control physical channel CCPCH (first common control physical channel P-CCPCH) is determined. The determination result of STTD application / non-application is obtained.

  In addition, the mobile communication terminal using the STTD application determination method of the present invention measures the reception electric field strength of the common pilot channel CPICH from the base station first transmission antenna by the preparation measurement means, and also measures the base station first by the measurement means. The base station obtained by measuring the reception electric field strength of the common pilot channel CPICH from the two transmission antennas and determining the threshold value for determining the presence / absence of transmission from the base station second transmission antenna by the threshold calculation means by the preparation measurement means The reception electric field strength of the common pilot channel CPICH from the base station second transmission antenna, which is calculated from the measured value of the reception electric field strength of the common pilot channel CPICH from the first transmission antenna and obtained by the determination means by this threshold value. To determine whether or not there is a transmission from the second transmitting antenna of the base station. It is intended to obtain a determination result of the STTD application and non-application of the common control physical channel CCPCH from fruits.

  Further, the mobile communication terminal using the STTD application determination method of the present invention calculates, from the measured value of the received electric field strength of the common pilot channel CPICH from the base station first transmission antenna obtained by the preparatory measurement means, by the threshold calculation means. The threshold for determining the presence / absence of transmission from the second transmission antenna of the base station is provided with an offset for making it easy for the determination means to determine that STTD is applied, resulting in a determination error regarding STTD application / non-application The effect of the case is reduced.

  In addition, the mobile communication terminal using the STTD application determination method of the present invention includes a common control physical channel demodulation unit that demodulates the common control physical channel CCPCH, and an STTD decoding unit that performs STTD decoding of the demodulation output of the common control physical channel CCPCH. , Having a control means for switching whether or not to operate the STTD decoding function of the STTD decoding means corresponding to the determination result by the determination means, and when the common control physical channel CCPCH is determined to be STTD application by the determination means, While the STTD decoding means is operated as STTD application, if it is determined that STTD is not applicable, the STTD decoding means is operated as STTD non-application, and the demodulation of the data modulated on the synchronization channel SCH by the synchronization channel demodulation means is performed. Common control physics Those that can determine the STTD application and non-application of the panel CCPCH.

  In addition, the mobile communication terminal using the STTD application determination method of the present invention includes an STTD application determination operation for the common control physical channel CCPCH based on demodulation of data modulated on the synchronization channel SCH by the synchronization channel demodulation means, Both the STTD application determination operation of the common control physical channel CCPCH based on the measurement of the reception electric field strength of the common pilot channel transmitted from the second transmission antenna is performed, and the STTD of the common control physical channel CCPCH is determined according to both determination results. By performing the application / non-application determination, it is possible to further improve the accuracy of the STTD application / non-application determination of the common control physical channel CCPCH.

  Further, the mobile communication terminal using the STTD application determination method of the present invention performs STTD application determination of the common control physical channel CCPCH based on the presence / absence of transmission from the base station second transmission antenna, and uses the result as a provisional determination. The demodulation of the common control physical channel CCPCH is first started based on this provisional determination, and then when the STTD application determination result is obtained from the demodulated data of the synchronization channel SCH, depending on the determination result or both determination results The final determination of STTD application / non-application of the common control physical channel CCPCH is performed, and the demodulation of the common control physical channel CCPCH is continued according to the final determination result.

  Therefore, the mobile communication terminal can start demodulating the modulated data of the common control physical channel CCPCH based on the provisional determination until it obtains the demodulation result of the data modulated on the synchronization channel SCH. The processing time is shortened, and after the final determination, the STTD application determination of the common control physical channel CCPCH is performed according to the final determination result, so that the accuracy of the STTD application / non-application determination of the common control physical channel CCPCH is determined. Can be increased.

  Furthermore, the mobile communication terminal using the STTD application determination method of the present invention can determine whether the STTD application / non-application determination result of the common control physical channel CCPCH based on the presence / absence of transmission of the base station second transmission antenna, or the synchronization channel SCH. If any one of the determination results of STTD application / non-application of the common control physical channel CCPCH based on demodulation of the modulated data is determined to be STTD application, the final STTD application determination result is determined to be STTD application, It is possible to reduce the influence when a determination error occurs.

  Further, the mobile communication terminal using the STTD application determination method according to the present invention determines whether or not STTD is applied / not applied to the common control physical channel CCPCH based on the presence / absence of transmission from the base station second transmission antenna. After starting the demodulation of the common control physical channel CCPCH and obtaining the STTD application / non-application determination result from the demodulated data of the synchronization channel SCH, the common control physical channel CCPCH is continuously demodulated according to the result. Thus, since the demodulation of the common control physical channel CCPCH can be started before the result of demodulation of the synchronization channel SCH is obtained, the processing time can be shortened.

  As described above, in the present invention, the reception level of the transmission signal from the second transmission antenna of the base station is measured from the received electric field strength of the common pilot channel CPICH, and from the measurement level, It is possible to determine the presence or absence of transmission output, and to determine whether STTD is applied or not applied to the common control physical channel CCPCH transmitted from the base station based on the determination result, thereby reducing the hardware scale and identifying the scrambling code. At the same time, the demodulation process of the common control physical channel CCPCH can be started, so that the processing time for determining the identified scrambling code can also be shortened in the three-stage cell search method.

  Further, the STTD application determination result of the common control physical channel CCPCH from the reception level measurement of the transmission signal from the base station second transmission antenna based on the reception electric field strength of the common pilot channel CPICH, and the demodulation of the data modulated on the synchronization channel SCH By obtaining the final determination result from both the STTD application determination result of the common control physical channel CCPCH based on the STTD, the reliability of the determination result of STTD application / non-application can be further improved. The demodulation of the common control physical channel CCPCH can be started in parallel with the demodulation of the synchronization channel SCH based on the STTD application determination result from the reception level measurement of the transmission signal from the second transmission antenna. The processing time required for demodulating the signal can be shortened.

[First Embodiment]
A STTD application determination method according to a first embodiment of the present invention and a mobile communication terminal using the STTD application determination method will be described with reference to the drawings.

FIG. 1 is a main part configuration diagram of a W-CDMA mobile communication terminal using the STTD application determination method according to the first embodiment of the present invention.
In FIG. 1, the W-CDMA mobile communication terminal 11 of this embodiment includes a level measurement unit 20, a determination unit 30, a P-CCPCH demodulation unit 40, a control unit 50, a selection unit 60, and an STTD decoding unit 70. Configured.

  The level measurement unit 20 receives a reception signal (baseband signal) of a transmission signal from the base station, which is received via a reception antenna (not shown) of the mobile communication terminal 11. The level measurement unit 20 measures the received electric field strength of the common pilot channel CPICH transmitted from the base station second transmission antenna.

  By the way, the frame of the common pilot channel CPICH is composed of a plurality of slots, and one slot is composed of repetition of a predetermined symbol pattern. This predetermined symbol pattern is different for each of the two antennas of the base station (base station first transmission antenna, base station second transmission antenna).

  Specifically, if the symbol “1 + j” is represented by “A”, the symbol pattern for the base station first transmission antenna is a pattern “+ A, + A, + A, + A,. On the other hand, the pattern for the base station second transmission antenna is a repetition of a pattern in which “+” and “−” are mixed, such as “+ A, −A, −A, + A,. Then, the base station applies channelization codes and scrambling to such predetermined symbol patterns “+ A, + A, + A, + A,...”, “+ A, −A, −A, + A,. The product multiplied by the ring code is transmitted.

  The level measurement unit 20 applies a 1-symbol interval obtained by performing complex despreading on the received signal (baseband signal) described above by applying the scrambling code obtained in the third step of the above-described three-stage cell search method. The signal obtained by integrating the minutes is multiplied by a symbol pattern “+ A, −A, −A, + A,...” Assigned to the base station second transmission antenna, and further several symbols (maintaining orthogonality between antennas). Therefore, the reception level of the transmission signal transmitted from the second transmission antenna of the base station, that is, the received electric field strength is measured based on an output obtained by performing an integration process (averaging process) over an even number of symbols) and performing phase estimation. . Then, the reception level of the transmission signal (here, common pilot channel CPICH) from the base station second transmission antenna measured by the level measurement unit 20 is supplied to the determination unit 30.

  Based on the measurement level supplied from the level measurement unit 20, the determination unit 30 determines whether the output method of the common control physical channel PCCPCH in the transmission signal from the base station is based on STTD application or non-application.

  Here, when two transmission antennas are used for transmission from the base station, STTD is not necessarily applied in the 3GPP standard. However, the purpose of using two antennas is to apply transmission diversity, and STTD encodes the same data from the base station and simultaneously transmits transmission signals from the two transmission antennas, thereby improving the transmission diversity effect. Since it is obtained, it is considered that STTD is not almost not applied when transmitting using two antennas. Therefore, the STTD application / non-application determination only needs to be able to measure the presence or absence of the transmission output from the base station second transmission antenna. Therefore, in the case of the present embodiment, the determination unit 30 determines the presence / absence of transmission output from the base station second transmission antenna by comparing the measurement level supplied from the level measurement unit 20 with the threshold level V. It is configured.

  In the present embodiment, fixed threshold level V1 is set in determination unit 30 as threshold level V related to reception of common pilot channel CPICH transmitted from the base station second transmission antenna. When the measurement level supplied from the level measurement unit 20 is A2, the determination unit 30 determines that the output from the base station second transmission antenna is “present” if V1 ≦ A2, and the base station if A2 <V1. It is determined that the output from the second transmission antenna is “none”. The determination result by the determination unit 30 is supplied to the control unit 50.

  Here, the threshold level V1 with which the determination unit 30 compares the measurement level A2 supplied from the level measurement unit 20 will be described in detail.

  FIG. 2 is a graph showing a probability distribution of data serving as a reference for determining the presence / absence of a transmission output from the base station second transmission antenna.

In FIG. 2, the vertical axis p (γ) represents the probability density of the signal-to-noise ratio γ, and the horizontal axis γ / N ^1/2 represents the signal amplitude because the N represents the noise level, which is a common pilot. This corresponds to the magnitude of the reception electric field strength of the channel CPICH.

  FIG. 2 shows a probability distribution characteristic P1 only for noise and a probability distribution characteristic P2 based on the sum of the signal and noise for the measurement level of transmission from the base station second transmission antenna supplied from the level measurement unit 20. Yes.

  The probability distribution characteristic P1 of only noise is that the STTD is not applied to the transmission of the common pilot channel CPICH from the base station, and a predetermined symbol pattern “+ A, assigned to the base station second transmission antenna from the base station second transmission antenna”. A transmission signal corresponding to a predetermined symbol pattern “+ A, + A, + A, + A,...” Is transmitted from only the base station first transmission antenna without transmitting a transmission signal corresponding to −A, −A, + A,. The probability distribution characteristic when transmitted is shown.

  On the other hand, the probability distribution characteristic P2 based on the sum of signal and noise applies STTD to the transmission of the common pilot channel CPICH from the base station, and a predetermined symbol pattern “+ A, + A, + A from the base station first transmission antenna. , + A,... Are transmitted at the same time, the base station second transmitting antenna transmits a predetermined symbol pattern “+ A, −A, −A, assigned to the base station second transmitting antenna. The probability distribution characteristics when a transmission signal corresponding to + A,.

Here, the amplitude γ / N ^1/2 of the signal corresponding to the threshold level V1 is ^defined as a threshold value b _th , and the threshold value b _th is _defined as

で表わした場合、判定部３０には、図２に示した両確率分布特性Ｐ１，Ｐ２の差違に基づいて、

, The determination unit 30 is based on the difference between the two probability distribution characteristics P1 and P2 shown in FIG.

に対応する受信電界強度のレベルＶ１が予め設定・保持されており、判定部３０は、この閾値ｂ_ｔｈのレベルＶ１に基づいて、上述のようにして、共通パイロットチャネルＣＰＩＣＨの基地局第２送信アンテナからの送信出力の有無を判定するようになっている。そして、この判定部３０の判定結果は、制御部５０に供給される。

Are previously set and held level V1 of the reception field intensity corresponding to the determination unit 30 based on the level V1 of the threshold b _th, as described above, the base station second transmitting common pilot channel CPICH The presence / absence of transmission output from the antenna is determined. Then, the determination result of the determination unit 30 is supplied to the control unit 50.

  The control unit 50 controls the operation of the selection unit 60 described later based on the determination result of the determination unit 30.

The P-CCPCH demodulator 40 demodulates the first common control physical channel P-CCPCH.
The P-CCPCH demodulation unit 40 includes two despreading units 42 and 44. Each despreading unit 42 and 44 receives a transmission signal from a base station received by the antenna of the mobile communication terminal 11. Each signal (baseband signal) is input.

  The despreading unit 42 applies a scrambling code to the input signal based on the frame head timing of the transmission signal from the base station first transmission antenna obtained in the second step, and transmits from the base station first transmission antenna. Complex despreading of the first common control physical channel P-CCPCH of the signal. From the despreading unit 42, a signal obtained by integrating one symbol period after despreading is output and supplied to the STTD decoding unit 70.

  The despreading unit 44 applies a scrambling code to the input signal based on the frame head timing of the transmission signal from the base station second transmission antenna obtained in the second step, and transmits from the base station second transmission antenna. Complex despreading of the first common control physical channel P-CCPCH of the signal. From the despreading unit 44, a signal obtained by integrating one symbol period after despreading is output and supplied to the selection unit 60.

  The selector 60 determines whether to output the despread output of the input signal supplied from the despreader 44 as it is or whether to output “0” instead of the despread output. Switching based on

  Whether or not the selection unit 60 outputs the despread output of the input signal supplied from the despreading unit 44 depends on whether or not STTD is applied on the transmission side, which is supplied from the determination unit 30. Accordingly, the control unit 50 selects the selection.

  That is, when STTD is applied to the transmission from the base station based on the determination result of the determination unit 30 described above, the control unit 50 outputs the despread output supplied from the despreading unit 44 to the STTD decoding unit 70 as it is. When the control signal for output is supplied to the selection unit 60 and STTD is not applied to the transmission from the base station, the STTD decoding unit regardless of the value of the despread output supplied from the despreading unit 44 A control signal for outputting “0” to 70 is supplied to the selector 60.

  As a result, in the P-CCPCH demodulation unit 40, the despread output from the despreading unit 44 based on reception of the transmission signal from the base station second transmission antenna is supplied to the STTD decoding unit 70 via the selection unit 60. On the other hand, the despread output from the despreading unit 42 based on reception of the transmission signal from the base station first transmission antenna is directly supplied to the STTD decoding unit 70 without going through the selection unit 60.

  Further, the STTD decoding unit 70 is configured so that the STTD decoding function always operates and when the input from the selection unit 60 is “0”, the same result as the output that is not STTD decoded is output as a result. It has become.

  Next, a demodulation method of the first common control physical channel P-CCPCH by the W-CDMA mobile communication terminal 11 according to the first embodiment configured as described above will be described with reference to FIG.

FIG. 3 is a flowchart of a demodulation process of the first common control physical channel P-CCPCH by the W-CDMA mobile communication terminal according to the first embodiment.
In FIG. 3, when the mobile communication terminal 11 is instructed to start a detection operation (step S110), the mobile communication terminal 11 performs the first step of the three-stage cell search method as described in the prior art to The slot head timing of the downstream frame is detected (step S120). Note that the detection operation is not limited to either the detection operation by soft handover in the communication state or the initial detection operation at power-on.

  The first step of the three-stage cell search method shown in step S120 may be any method regarding the specific method, but in the present embodiment, the first step A method of acquiring the correlation value using one synchronization channel P-SCH and detecting that the timing at which a sufficiently large correlation value is obtained is the slot head timing of the downlink frame from the base station by the internal timing management function Is used.

  In the following description, in order to facilitate understanding, an example is given in which the mobile communication terminal 11 can detect only one path (one cell) of a downlink frame from the base station by the process of step S120. explain.

  When the mobile communication terminal 11 detects the slot head timing of the downlink frame from the base station in step S120, the mobile communication terminal 11 executes the second step of the three-stage cell search method as described in the prior art at the detected slot head timing. By doing so, the synchronization of the frame head timing and the identification of the scrambling code group including the scrambling code are performed (step S130).

  Regarding the second step of the three-stage cell search method shown in step S130, the specific method may be any method, but in the present embodiment, a general second synchronization is performed. A method is used in which a correlation value is obtained using the channel S-SCH, a scrambling code group is detected by detecting the sequence, and a frame head timing is detected by using an internal timing management function together.

  Next, when identification of the scrambling code group and detection of the frame head timing are performed in step S130, the mobile communication terminal 11 performs the three-stage cell search method as described in the prior art according to the detected frame head timing. By executing the third step, the scrambling code identification process of the currently searched base station is performed (step S140).

  Regarding the third step of the three-stage cell search method shown in step S140, any specific method may be used, but in the present embodiment, a general step S130 is used. A correlation value is obtained for all the scrambling code candidates included in the identified scrambling code group, and the scrambling code of the base station is obtained with the maximum correlation value among them, and the scrambling with a sufficiently large correlation value. A method for determining a ring code is used.

  Thereafter, the mobile communication terminal 11 performs demodulation processing of the first common control physical channel P-CCPCH using the determined scrambling code, and confirms the cyclic redundancy check CRC of the demodulated data, thereby performing the search. It is necessary to determine the scrambling code of the selected base station.

  In this case, if the mobile communication terminal 11 has no information about STTD application / non-application regarding the first common control physical channel P-CCPCH of the cell corresponding to the scrambling code identified in step S140, In this case, STTD application determination of the first common control physical channel P-CCPCH is performed by demodulating the data modulated on the synchronization channel SCH.

  Therefore, in the mobile communication terminal 11 according to the present embodiment, the base station scrambling code identification process (step S140) in the third step of the above-described three-step cell search method is performed from the base station second transmitting antenna. An STTD application determination process (step S150) is performed in which the output of the transmission signal is measured with the received electric field strength of the common pilot channel CPICH and the STTD application / non-application of the first common control physical channel P-CCPCH is determined based on the measurement result. In parallel processing (parallel processing).

  That is, when the mobile communication terminal 11 obtains the correlation value in the third step of step S140 for all the scrambling code candidates included in the scrambling code group identified in step S130, the level measurement unit shown in FIG. 20 and the determination part 30 perform the following processes.

The level measurement unit 20 uses the scrambling code candidates in parallel with the scrambling code candidates included in the scrambling code group identified in step S130, and uses the scrambling code candidates in parallel with the base station second transmission antenna. The reception level (reception field strength level) of the transmission signal transmitted from is measured, and the measured reception level is supplied to the determination unit 30. The determination unit 30 compares the measurement level supplied from the level measurement unit 20 with the level V1 of the threshold value b _th described above, and determines whether the output method of the transmission signal from the base station second transmission antenna is based on STTD application. Is determined (step S150).

  Thereby, in the mobile communication terminal 11, after identifying the scrambling code of the base station (step S140), the control unit 50 and the level measuring unit 20 performed in parallel with the identification processing of the scrambling code of the base station Based on the result of the STTD application / non-application determination process by the determination unit 30 (step S150), the control signal is supplied to the selection unit 60 (step S160).

  That is, when the first common control physical channel P-CCPCH is applied to STTD, the control unit 50 uses the despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 as it is as the STTD decoding unit 70. Is supplied to the selection unit 60 (step S170), and when STTD is not applied, it relates to the despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40. Instead, a control signal for outputting “0” to the STTD decoding unit 70 is supplied to the selection unit 60 (step S171).

  When the despread output of the despreading unit 44 of the P-CCPCH demodulating unit 40 is supplied via the selection unit 60 according to the input supplied from the selection unit 60, the STTD decoding unit 70 The first common control physical channel P to which STTD is applied by performing STTD decoding processing based on the despread output supplied from the despreader 42 of the CCPCH demodulator 40 and the despread output supplied from the despreader 44. -When the CCPCH is demodulated and "0" is supplied instead of the despread output supplied from the despreader 44 from the selector 60, the result is the same as in the case where STTD decoding is not performed. -Based on only the despread output supplied from the despreading unit 42 of the CCPCH demodulating unit 40, the first common control physical channel P-CCPCH is demodulated without performing the STTD decoding process. Step S180).

  As described above, according to the W-CDMA mobile communication terminal 11 of the present embodiment, the STTD application / non-application determination of the first common control physical channel P-CCPCH is performed in parallel with the identification of the scrambling code. Therefore, in the demodulation processing of the first common control physical channel P-CCPCH, the STTD application / non-application of the first common control physical channel P-CCPCH is determined from the total demodulation processing time of the first common control physical channel P-CCPCH. Therefore, the time spent for demodulating the synchronization channel SCH can be reduced, and the hardware scale can be reduced.

[Second Embodiment]
Next, the STTD application determination method according to the second embodiment of the present invention and the W-CDMA mobile communication terminal 12 using the STTD application determination method will be described with reference to FIG.

  In the description of the W-CDMA mobile communication terminal 12 according to the present embodiment, the same or similar components as those of the W-CDMA mobile communication terminal 11 according to the first embodiment described above are denoted by the same reference numerals. Detailed description thereof will be omitted.

  FIG. 4 is a main part configuration diagram of a W-CDMA mobile communication terminal using the STTD application determination method according to the second embodiment of the present invention.

  4, the W-CDMA mobile communication terminal 12 according to the present embodiment includes first and second level measurement units 22 and 24, a calculation unit 32, a determination unit 34, a P-CCPCH demodulation unit 40, and a control unit 50. The selection unit 60 and the STTD decoding unit 70 are provided.

  In the W-CDMA mobile communication terminal 12 of the present embodiment, the first and second level measurement units 22 and 24 receive from the base station received via a reception antenna (not shown) of the mobile communication terminal 12. The received signal (baseband signal) of the transmitted signal is input.

  The first level measurement unit 22 measures the transmission output level from the base station first transmission antenna using the common pilot channel CPICH.

  The first level measurement unit 22 performs complex despreading by applying the scrambling code included in the scrambling code group obtained in the second step of the above-described three-stage cell search method to the received signal described above. The signal obtained by integrating one symbol interval is multiplied by a symbol pattern “+ A, + A, + A, + A,...” Assigned to the base station first transmission antenna, and further several symbols (orthogonal between antennas). In order to maintain the characteristics, it is desirable to use even symbols). Based on the output obtained by performing phase estimation and performing phase estimation (average processing), the reception level of the transmission signal transmitted from the base station first transmission antenna, that is, the common pilot channel The CPICH received electric field strength is measured.

  Then, the reception level of the transmission signal (here, common pilot channel CPICH) from the base station first transmission antenna measured by the first level measurement unit 22 is supplied to the calculation unit 32.

  Similar to the level measurement unit 20 in the first embodiment, the second level measurement unit 24 measures the transmission output level from the base station second transmission antenna using the common pilot channel CPICH. The measurement output from the second level measurement unit 24 is supplied to the determination unit 34.

  The calculation unit 32 determines a threshold value for determining whether there is a transmission output from the base station second transmission antenna based on the measurement level of the base station first transmission antenna measured by the first level measurement unit 22. Level V2 is calculated. The threshold level V2 calculated by the calculation unit 32 is supplied to the determination unit 34.

  The determination unit 34 compares the measurement level of the base station second transmission antenna supplied from the second level measurement unit 24 with the threshold level V2 supplied from the calculation unit 32, thereby It is determined whether or not the transmission output is due to STTD application.

  The configurations of the P-CCPCH demodulation unit 40, the control unit 50, the selection unit 60, and the STTD decoding unit 70 are the same as or similar to the W-CDMA mobile communication terminal 11 of the first embodiment described above. The description about each detail is abbreviate | omitted.

  FIG. 5 is a graph showing a probability distribution of data serving as a reference for determining the presence / absence of transmission output from the base station second transmission antenna.

In FIG. 5, the vertical axis p (γ) represents the probability density of the SN ratio γ, the horizontal axis γ / N ^1/2 represents the amplitude of the signal because N represents the noise level, and the common pilot channel CPICH Corresponds to the magnitude of the received electric field strength.

  In addition, in FIG. 2, with respect to the measurement level of the base station second transmission antenna supplied from the second level measurement unit 24, the probability distribution characteristic P <b> 1 with only noise and the probability distribution characteristic P <b> 2 with the sum of the signal and noise Is shown.

Here, the amplitude γ / N ^1/2 of the signal corresponding to the threshold level V2 is ^defined as a threshold value b _th , and the threshold value b _th is _defined as

で表わすと、閾値ｂ_ｔｈは、次の式（１）を用いて求めることができる。

In this case, the threshold value b _th can be obtained using the following equation (1).

With respect to the threshold b _th as the optimum threshold for minimizing the error rate (in this case, the error rate of the STTD application determination) with respect to the SN ratio γ described as the equation (1), “S. Stein, Co-authored by JJ Jones; written by Hideo Seki, “Contemporary Communication Line Theory”, published by Morikita Publishing, 1970.10, detailed description thereof is omitted.

  Here, the output level S from the base station can be obtained as the output level from the first transmission antenna of the base station by the electric field strength when the mobile communication terminal 12 receives the common pilot channel CPICH. That is, the output level from the base station first transmission antenna shown in FIG. 4 can be obtained based on the measurement level supplied from the first level measurement unit 22 that measures using the common pilot channel CPICH.

  The noise level N is the synchronization channel SCH and the synchronization channel when synchronizing with the slot head timing of the received signal (received data) from the base station in the first step of the three-stage cell search method. Since the transmission power of the common pilot channel CPICH and the common control physical channel CCPCH other than the SCH is fixed for each base station, it can be obtained by performing an averaging process for one slot.

The calculation unit 32 obtains the SN ratio γ based on the obtained signal level S and noise level N, and corresponds to an adaptive threshold b _th that minimizes the error rate based on the SN ratio γ based on the above equation (1). The calculated level V2 is calculated.

  Note that the averaging process of one slot for obtaining the noise level N in the calculation unit 32 is not necessarily performed in the process of the first step of the three-stage cell search method, and the second step of the three-stage cell search method. Even if it carries out by the process of etc., it does not matter.

  Then, the threshold level V2 calculated by the calculation unit 32 is supplied to the determination unit 34, and is used for the STTD application / non-application determination.

  For example, when the measurement level of the base station second transmission antenna supplied from the level measurement unit 24 is A2, the determination unit 34 determines that the transmission output from the base station second transmission antenna is “V2 ≦ A2”. If A2 <V2, the transmission output from the base station second transmission antenna is determined to be “none”. The determination result is supplied from the determination unit 34 to the control unit 50.

In this embodiment, the mobile communication terminal 12, based on the threshold level V2 corresponding to the threshold b _th supplied by the calculation unit 32, the demodulation of the first common control physical channel P-CCPCH described in FIG. 3 described above By executing the processing flowchart, the demodulation process of the first common control physical channel P-CCPCH corresponding to the STTD application / non-application of the first common control physical channel P-CCPCH is Similar to the mobile communication terminal 11 of the embodiment, the total processing time can be shortened.

  Furthermore, according to the W-CDMA mobile communication terminal 12 of the present embodiment, the determination unit 34 determines whether the output method of the first common control physical channel P-CCPCH from the base station is STTD application / non-application. Since the threshold level V2 used for the transmission can be adaptively changed according to the S / N ratio γ at the time of reception of the transmission signal from the base station, the communication environment with the base station (especially reception from the base station) Even when the (environment) changes, it is possible to reduce the determination error of STTD application / non-application.

[Third Embodiment]
Next, the STTD application determination method according to the third embodiment of the present invention and the W-CDMA mobile communication terminal 13 using the STTD application determination method will be described with reference to FIG.

The configuration of the mobile communication terminal 13 of the present embodiment is almost the same as the configuration of the W-CDMA mobile communication terminal 12 of the second embodiment shown in FIG. The offset coefficient α is stored, and the calculation unit 32 is further configured to obtain the threshold value b _th ′ using the stored offset coefficient α. The mobile communication for W-CDMA of the second embodiment This is different from the configuration of the terminal 12.

That is, the formula for obtaining the optimum threshold (threshold value b _th ) shown in the formula (1) minimizes the error rate with respect to the S / N ratio γ, but is generally not applied when STTD is applied. In the case of demodulating, the deterioration is greater than in the case of demodulating by determining that it is applied when STTD is not applied.

Therefore, in the mobile communication terminal 13 of the present embodiment, the calculation unit 32 further calculates the adaptive threshold value b _th that minimizes the error rate by the SN ratio γ, based on the equation (1). The threshold value b _th is offset so as to reduce the probability of being erroneously applied when STTD is applied, and the probability of being erroneously applied when STTD is not applied is increased, thereby improving the accuracy of subsequent processing, and as a result, the first common control physics is totally achieved. The demodulation performance of the channel P-CCPCH is improved.

Here, for example, when a predetermined offset coefficient α is used, the relationship between the threshold value b _th calculated based on the equation (1) and the offset threshold value b _th ′ is expressed by the following equation (2): It can be expressed as

  Here, as a specific example of the offset coefficient α, for example, 0.8 is selected.

According to the W-CDMA mobile communication terminal 13 of the present embodiment, the transmission output from the base station second transmission antenna is STTD applied based on the threshold level V3 corresponding to the threshold value b _th ′ supplied from the calculation unit 32. The determination result of the determination unit 34 that determines whether or not is due to the STTD is less likely to be unapplied when STTD is applied, and increases the probability of being erroneously applied when STTD is not applied. The demodulation performance of one common control physical channel P-CCPCH can be improved.

[Fourth Embodiment]
Next, the STTD application determination method according to the fourth embodiment of the present invention and the W-CDMA mobile communication terminal 14 using the STTD application determination method will be described with reference to FIGS.

  FIG. 6 is a block diagram of a main part of a W-CDMA mobile communication terminal using the STTD application determination method according to the fourth embodiment of the present invention.

  In FIG. 6, the W-CDMA mobile communication terminal 14 of the present embodiment includes first and second level measurement units 22 and 24, a calculation unit 32, a first determination unit 34, a P-CCPCH demodulation unit 40, In addition to the control unit 50, the selection unit 60, and the STTD decoding unit 70, an SCH demodulation unit 82, a second determination unit 84, and a final STTD application determination unit 86 are further provided.

  In the description of the W-CDMA mobile communication terminal 14 of the present embodiment, the same or similar components as those of the mobile communication terminals 11 to 13 of the first to third embodiments described above are the same. Reference numerals are assigned and detailed descriptions thereof are omitted.

  In FIG. 6, the input signal is a reception signal (baseband signal) input from a reception antenna (not shown) of the mobile communication terminal 14 as in the case of the above-described embodiment.

  The first level measurement unit 22 measures the received electric field strength of the common pilot channel CPICH transmitted from the base station first transmission antenna.

  Then, the reception level of the transmission signal from the base station first transmission antenna measured by the first level measurement unit 22 (here, the reception level of the common pilot channel CPICH) is supplied to the calculation unit 32.

  Similar to the first level measurement unit 22, the second level measurement unit 24 measures the received electric field strength of the common pilot channel CPICH transmitted from the base station second transmission antenna. The measurement level obtained by the second level measurement unit 24 is input to the first determination unit 34.

The calculation unit 32 determines whether there is a transmission output from the base station second transmission antenna based on the reception level of the transmission signal from the base station first transmission antenna measured by the first level measurement unit 22. The threshold level V4 corresponding to the threshold value b _th or b _th ′ is calculated. The threshold level V4 (that is, V2 or V3) calculated by the calculation unit 32 is supplied to the first determination unit 34.

  The first determination unit 34 determines the measurement level of the base station second transmission antenna supplied from the second level measurement unit 24 in the same manner as the determination unit 34 described in the second and third embodiments. By comparing with the threshold level V4 supplied from the calculation unit 32, it is determined whether or not the transmission output from the base station second transmission antenna is due to STTD application. At this time, the threshold level V4 supplied from the calculation unit 32 is obtained based on the reception level of the output of the base station first transmission antenna, and thus is used as an adaptive threshold in the first determination unit 34. . Thereby, if the reception level A2 of the transmission signal from the base station second transmission antenna is higher than the threshold level V4 (V4 ≦ A2), the first determination unit 34 transmits the transmission output from the base station second transmission antenna. Is determined to be “present” and STTD decoding processing is performed, and if the reception level A2 of the transmission signal from the base station second transmission antenna is smaller than the threshold level V4 (A2 <V4), the first The determination unit 34 determines that the transmission output from the base station second transmission antenna is “none”, and determines that the STTD decoding process is not performed.

  The SCH demodulator 82 demodulates the data modulated on the synchronization channel P-SCH transmitted from the base station using the scrambling code of the base station obtained in the third step of the three-step cell search method. .

  The second determination unit 84 determines whether STTD is applied to the first common control physical channel P-CCPCH based on the data modulated on the demodulated first synchronization channel P-SCH.

  The final STTD application determination unit 86 determines whether STTD is applied to the first common control physical channel P-CCPCH based on the determination results supplied from the first determination unit 34 and the second determination unit 84, respectively. Determine. The determination result of STTD application / non-application by the final STTD application determination unit 86 is supplied to the control unit 50.

  In the case of the present embodiment, control unit 50 controls and operates selection unit 60 based on the STTD application / non-application determination result supplied from final STTD application determination unit 86.

  The configurations of the P-CCPCH demodulation unit 40, the control unit 50, the selection unit 60, and the STTD decoding unit 70 are the same as those of the W-CDMA mobile communication terminals 11 to 13 in the first to third embodiments described above. is there.

  Next, a method for demodulating the first common control physical channel P-CCPCH by the W-CDMA mobile communication terminal 14 according to the fourth embodiment configured as described above will be described with reference to FIG.

  FIG. 7 is a flowchart of the demodulation processing of the first common control physical channel P-CCPCH by the W-CDMA mobile communication terminal according to the fourth embodiment.

  In FIG. 7, when the mobile communication terminal 14 is instructed to start the detection operation (step S110), the mobile communication terminal 14 executes the first step of the three-stage cell search method to thereby obtain the slot start timing of the downlink frame from the base station. Is detected (step S120). Note that the detection operation is not limited to either the detection operation by soft handover in the communication state or the initial detection operation at power-on.

  For the first step of the three-stage cell search method shown in step S120, any specific method may be used, but in the present embodiment, a general first synchronization is performed. A method is used in which the correlation value is obtained using the channel P-SCH, and the timing at which a sufficiently large correlation value is obtained is the slot start timing of the downlink frame from the base station by the internal timing management function. ing.

  In the following description, in order to facilitate understanding, an example in which the mobile communication terminal 14 can detect only one path (one cell) of a downlink frame from the base station by the process of step S120 will be described. To do.

  When the mobile communication terminal 14 detects the slot head timing of the downlink frame from the base station in step S120, the mobile communication terminal 14 executes the second step of the three-stage cell search method at the detected slot head timing, thereby obtaining the frame head timing. And the scrambling code group including the scrambling code are identified (step S130).

  The specific method of the second step of the three-stage cell search method shown in step S130 may be any method, but in this embodiment, a general second synchronization channel S is used. -A method is used in which a correlation value is obtained using SCH, and a frame head timing is detected by using the scrambling code group and the internal timing management function together by detecting the sequence.

  Next, when identification of the scrambling code group and detection of the frame head timing are performed in step S130, the mobile communication terminal 14 performs the three-stage cell search method as described in the prior art according to the detected frame head timing. By executing the third step, the scrambling code identification process of the currently searched base station is performed (step S140).

  The specific method of the third step of the three-stage cell search method shown in step S140 may be any method, but in the present embodiment, it is identified by general step S130. A correlation value is obtained for all the scrambling code candidates included in the scrambling code group, and the scrambling code of the base station is converted into a scrambling code that has the maximum correlation value and a sufficiently large correlation value. A method of determining is used.

  In addition, in the mobile communication terminal 14 according to the present embodiment, the base station scrambling code identification process (step S140) in the third step of the above-described three-stage cell search method and transmission from the base station second transmission antenna are performed. The measurement process for measuring the signal output with the received electric field strength of the common pilot channel CPICH and the STTD application determination process for the first common control physical channel P-CCPCH based on the measurement result of the measurement process are performed in parallel processing (step S150). .

  That is, when the mobile communication terminal 14 obtains the correlation value in step S140 for all the scrambling code candidates included in the scrambling code group identified in step S130, the first and second level measurements shown in FIG. The units 22 and 24, the calculation unit 32, and the first determination unit 34 perform the following processing.

  The first level measurement unit 22 uses the scrambling code candidates in parallel with the scrambling code candidates in parallel to obtain correlation values for all the scrambling code candidates included in the scrambling code group identified in step S130. The reception level of the transmission signal transmitted from one transmission antenna is measured, and the measured reception level is supplied to the calculation unit 32. The calculation unit 32 determines whether or not there is a transmission output from the base station second transmission antenna based on the measurement level from the base station first transmission antenna measured by the first level measurement unit 22. The threshold level V4 is calculated, and this threshold level V4 is supplied to the first determination unit 34.

  On the other hand, the second level measurement unit 24 also uses the scrambling code candidates in parallel to obtain correlation values for all the scrambling code candidates included in the scrambling code group identified in step S130. Then, the reception level of the transmission signal transmitted from the base station second transmission antenna is measured, and the measured reception level is supplied to the first determination unit 34.

In addition, the first determination unit 34 compares the measurement level from the base station second transmission antenna supplied from the second level measurement unit 24 with the threshold level V4 supplied from the calculation unit 32. Then, it is determined whether or not the transmission output from the base station second transmission antenna is due to STTD application. At this time, since the threshold value b _th or b _th ′ to which the threshold level V4 supplied from the calculation unit 32 corresponds is obtained based on the reception level of the output of the base station first transmission antenna, the first determination unit 34 Then, this threshold level V4 is used as an adaptive threshold. Thereby, if the reception level A2 of the transmission signal from the base station second transmission antenna is higher than the threshold level V4 (V4 ≦ A2), the first determination unit 34 transmits the transmission output from the base station second transmission antenna. Is determined to be “present”, STTD application is determined, and if the reception level A2 of the transmission signal from the base station second transmission antenna is smaller than the threshold level V4 (A2 <V4), the first determination unit 34 Determines that the transmission output from the second transmission antenna of the base station is “none”, and determines that STTD is not applied. The determination result by the first determination unit 34 is supplied to the final STTD application determination unit 86.

  In the case of the mobile communication terminal 14 of the present embodiment, even if the determination result by the first determination unit 34 is supplied to the final STTD application determination unit 86, the determination result from the second determination unit 84 described later is If the final STTD application determination unit 86 has not been supplied yet, the final STTD application determination unit 86 does not supply the determination result to the control unit 50.

  By the way, when the scrambling code of the base station is identified by the third step of the three-stage cell search method shown in step S140 described above, the mobile communication terminal 14 uses the identified scrambling code, A determination process (step S151) for demodulating data (synchronization information) modulated on the synchronization channel SCH to determine STTD application / non-application of the first common control physical channel P-CCPCH, and the first common control physical channel P-CCPCH demodulation processing (step S153) is executed.

  That is, in the mobile communication terminal 14, as the STTD application determination process shown in step S151, the SCH demodulator 82 uses the scrambling code obtained in step S140 to transmit the synchronization channel P-SCH transmitted from the base station. Demodulate the modulated data. Then, the second determination unit 84 determines whether STTD is applied to the first common control physical channel P-CCPCH based on the data modulated on the demodulated synchronization channel P-SCH, The determination result is supplied to the final STTD application determination unit 86.

  Further, as the P-CCPCH demodulation processing shown in step S153, the P-CCPCH demodulation unit 40 uses the scrambling code obtained in step S140 to transmit the first common control physical channel P-CCPCH transmitted from the base station. Is demodulated. At that time, the despreading unit 42 of the P-CCPCH demodulation unit 40 uses the scrambling code to complex despread the slot of the first common control physical channel P-CCPCH transmitted from the base station first transmission antenna. Then, a signal obtained by integrating the one symbol interval is supplied to the STTD decoding unit 80. Further, the despreading unit 44 of the P-CCPCH demodulation unit 40 uses the scrambling code to complex despread the slot of the first common control physical channel P-CCPCH transmitted from the base station second transmission antenna, A signal obtained by integrating the one symbol interval is supplied to the selection unit 60. In the present embodiment, control unit 50 has a larger influence when it is erroneously applied when STTD is applied than when it is erroneously applied when STTD is not applied. At the beginning when STTD is not supplied, after the scrambling code identification process in step S140, PTD is supplied until the determination result is supplied from the final STTD application determination unit 86, as in the case where STTD described below is applied. The control signal for causing the STTD decoding unit 70 to output the despread output of the input signal supplied from the despreading unit 44 of the -CCPCH demodulating unit 40 as it is is supplied to the selection unit 60.

  On the other hand, in the mobile communication terminal 14, the determination result of STTD application / non-application of the first common control physical channel P-CCPCH by the first determination unit 34 is supplied to the final STTD application determination unit 86 by the process of step S150. When the STTD application / non-application determination result of the first common control physical channel P-CCPCH by the second determination unit 84 is supplied to the final STTD application determination unit 86 by the process of S151, the final STTD application determination unit 86 Based on each determination result, it is finally determined whether STTD is applied to the first common control physical channel P-CCPCH (step S152).

  FIG. 8 shows a state in which the final STTD application determining unit in the W-CDMA mobile communication terminal according to the present embodiment finally determines whether STTD is applied to the first common control physical channel P-CCPCH. It is a table.

  As shown in FIG. 8, the final STTD application determination unit 86 applies both STTD application determination based on the presence / absence of transmission from the base station second transmission antenna and STTD application determination from the demodulated data of the synchronization channel SCH. If it is determined that STTD is applied, STTD application processing is performed. Conversely, if both determine that STTD is not applied, processing of STTD non-application is performed.

  When the STTD application determination based on the presence / absence of transmission from the base station second transmit antenna and the STTD application determination from the demodulated data of the synchronization channel SCH give different results, the STTD application result is not applied when STTD is applied. Is more affected than when it is erroneously applied when STTD is not applied. Therefore, STTD application determination based on presence / absence of transmission from the base station second transmission antenna, or STTD from demodulated data of the synchronization channel SCH. If either of the application determinations determines that the STTD is applied, the final STTD application determination unit 86 performs the STTD application determination.

  The determination process by the final STTD application determining unit 86 can increase the probability of erroneous application when STTD is not applied than when erroneously applied when STTD is applied. As a result, the first common control physical channel is totally added. The demodulation performance of P-CCPCH can be improved.

  Thereby, in the mobile communication terminal 14, the control unit 50 supplies a control signal to the selection unit 60 based on the STTD application / non-application determination processing result by the final STTD application determination unit 86 (step S152). (Step S160).

  That is, when the first common control physical channel P-CCPCH is applied to STTD, the control unit 50 uses the despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 as it is as the STTD decoding unit 70. Is supplied to the selection unit 60 (step S170). When STTD is not applied, a despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 is provided. Regardless of this, a control signal for outputting “0” to the STTD decoding unit 70 is supplied to the selection unit 60 (step S171).

  When the despread output of the despreading unit 44 of the P-CCPCH demodulating unit 40 is supplied via the selection unit 60 according to the input supplied from the selection unit 60, the STTD decoding unit 70 The first common control physical channel P to which STTD is applied by performing STTD decoding processing based on the despread output supplied from the despreader 42 of the CCPCH demodulator 40 and the despread output supplied from the despreader 44. -When the CCPCH is demodulated and "0" is supplied instead of the despread output supplied from the despreader 44 from the selector 60, the result is the same as in the case where STTD decoding is not performed. The demodulation process of the first common control physical channel P-CCPCH is performed without performing the STTD decoding process based only on the despread output supplied from the despreading unit 42 of the CCPCH demodulating unit 40. (Step S180).

  Thus, according to the W-CDMA mobile communication terminal 14 of the present embodiment, the first common control physical channel P-CCPCH corresponding to the STTD application / non-application of the first common control physical channel P-CCPCH. For the demodulation process, STTD application determination based on the presence / absence of transmission from the base station second transmission antenna and STTD application determination from the demodulated data of the synchronization channel SCH are used, and the first common control is determined from the result of each STTD application determination. Since the final STTD application determination unit 86 finally determines whether or not the STTD is applied to the physical channel P-CCPCH, the determination accuracy can be improved, and as a result, the total PCCPCH demodulation performance can be improved. Can do.

  Furthermore, the determination of STTD application / non-application by the final STTD application determination unit 86 also increases the probability of erroneous application when STTD is applied rather than when it is erroneously applied when STTD is applied. In addition, it is possible to further improve the PCCPCH demodulation performance.

[Fifth Embodiment]
A W-CDMA mobile communication terminal using the STTD application determination method according to the fifth embodiment of the present invention will be described.

  The W-CDMA mobile communication terminal 15 of the present embodiment is similar to the W-CDMA mobile communication terminal 14 of the fourth embodiment shown in FIG. 24, calculation unit 32, first determination unit 34, P-CCPCH demodulation unit 40, control unit 50, selection unit 60, STTD decoding unit 70, SCH demodulation unit 82, second determination unit 84, and final STTD application determination A portion 86 is provided.

  The W-CDMA mobile communication terminal 15 of the present embodiment is different from the W-CDMA mobile communication terminal 14 of the fourth embodiment only in the determination configuration of the final STTD application determination unit 86, and the configuration of each other unit Is the same as or similar to the configuration of each corresponding part of the W-CDMA mobile communication terminal 14 of the fourth embodiment, and a description thereof will be omitted.

  In the present embodiment, the final STTD application determination unit 86 is supplied with the STTD application / non-application determination result from the first determination unit 34 based on the presence / absence of transmission from the base station second transmission antenna. Even if the STTD application / non-application determination result from the second determination unit 84 based on the demodulated data of the synchronization channel SCH is not yet supplied, the STTD application / non-application based only on the determination result from the first determination unit 34 A provisional determination of a final determination that is not applicable is performed. Then, the final STTD application determination unit 86 is configured to start supplying the result of the temporary determination to the control unit 50 as the final determination result from this temporary determination time point.

  After that, the final STTD application determination unit 86 is supplied with the STTD application / non-application determination result from the second determination unit 84 based on the demodulated data of the synchronization channel SCH. As in the mobile communication terminal 14 of the form, STTD is applied to the first common control physical channel P-CCPCH based on the determination results supplied from the first determination unit 34 and the second determination unit 84, respectively. It is finally determined whether or not. Then, even if the final determination result described above as the final determination result has already been supplied from the final STTD application determination unit 86 to the control unit 50, the final STTD application determination unit 86 subsequently uses the temporary determination result as the temporary determination result. Instead, the STTD application / non-application determination results obtained based on the determination results supplied from the first determination unit 34 and the second determination unit 84 are supplied to the control unit 50 as final determination results. It has become.

  FIG. 9 is a flowchart of demodulation processing of the first common control physical channel P-CCPCH by the W-CDMA mobile communication terminal according to the fifth embodiment.

  In FIG. 9, when the mobile communication terminal 15 is instructed to start a detection operation (step S110), by executing the first step of the three-stage cell search method, the slot start timing of the downlink frame from the base station Is detected (step S120). Note that the detection operation is not limited to either the detection operation by soft handover in the communication state or the initial detection operation at power-on.

  For the first step of the three-stage cell search method shown in step S120, any specific method may be used, but in the present embodiment, a general first synchronization is performed. A method is used in which the correlation value is obtained using the channel P-SCH, and the timing at which a sufficiently large correlation value is obtained is the slot start timing of the downlink frame from the base station by the internal timing management function. ing.

  In the following description, in order to facilitate understanding, an example in which the mobile communication terminal 15 can detect only one path (one cell) of a downlink frame from the base station by the process of step S120 will be described. To do.

  When the mobile communication terminal 15 detects the slot head timing of the downlink frame from the base station in step S120, the mobile communication terminal 15 executes the second step of the three-stage cell search method at the detected slot head timing, thereby obtaining the frame head timing. And scrambling code groups including scrambling codes are identified.

  The specific method of the second step of the three-stage cell search method shown in step S130 may be any method, but in this embodiment, a general second synchronization channel S is used. A method is used in which a correlation value is obtained using the SCH, and the frame head timing is detected by using the scrambling code group and the internal timing management function together by detecting the sequence.

  Next, when the identification of the scrambling code group and the detection of the frame head timing are performed in step S130, the mobile communication terminal 15 performs the three-step cell search as described in the prior art according to the detected frame head timing. By executing the third step of the method, the scrambling code identification process of the currently searched base station is performed (step S140).

  The specific method of the third step of the three-stage cell search method shown in step S140 may be any method, but in the present embodiment, it is identified by general step S130. A correlation value is obtained for all the scrambling code candidates included in the scrambling code group, and the scrambling code of the base station is converted into a scrambling code that has the maximum correlation value and a sufficiently large correlation value. Use the method of determination.

  In addition, in the mobile communication terminal 15 of the present embodiment, the base station scrambling code identification process (step S140) according to the third step of the above-described three-step cell search method and transmission from the base station second transmission antenna are performed. The measurement process for measuring the signal output with the received electric field strength of the common pilot channel CPICH and the STTD application determination process for the first common control physical channel P-CCPCH based on the measurement result of the measurement process are performed in parallel processing (step S150). .

  That is, when the mobile communication terminal 15 obtains the correlation value in step S140 for all the scrambling code candidates included in the scrambling code group identified in step S130, the first and second level measurements shown in FIG. The units 22 and 24, the calculation unit 32, and the first determination unit 34 perform the following processing.

  The first level measurement unit 22 uses the scrambling code candidates in parallel with the scrambling code candidates in parallel to obtain correlation values for all the scrambling code candidates included in the scrambling code group identified in step S130. The reception level of the transmission signal transmitted from one transmission antenna is measured, and the measured reception level is supplied to the calculation unit 32. The calculation unit 32 determines a threshold level V5 for determining whether there is a transmission output from the base station second transmission antenna based on the measurement level of the base station first transmission antenna measured by the level measurement unit 22. The threshold level V5 is calculated and supplied to the first determination unit 34.

  On the other hand, the second level measurement unit 24 also uses the scrambling code candidates in parallel to obtain correlation values for all the scrambling code candidates included in the scrambling code group identified in step S130. Then, the reception level of the transmission signal transmitted from the base station second transmission antenna is measured, and the measured reception level is supplied to the first determination unit 34.

Then, the first determination unit 34 compares the measurement level from the base station second transmission antenna supplied from the level measurement unit 24 with the threshold level V5 supplied from the calculation unit 32, thereby It is determined whether or not the transmission output from the station second transmission antenna is due to STTD application. At this time, since the threshold value b _th or b _th ′ to which the threshold level V5 supplied from the calculation unit 32 corresponds is obtained based on the reception level of the output of the base station first transmission antenna, the first determination unit 34 Then, this threshold level V5 is used as an adaptive threshold. Thus, if the reception level A2 of the transmission signal from the base station second transmission antenna is higher than the threshold level V5 (V5 ≦ A2), the first determination unit 34 transmits the transmission output from the base station second transmission antenna. Is determined to be “present”, the STTD application is determined, and if the reception level A2 of the transmission signal from the base station second transmission antenna is smaller than the threshold level V5 (A2 <V5), the first determination unit 34 Determines that the transmission output from the second transmission antenna of the base station is “none”, and determines that STTD is not applied. The determination result by the first determination unit 34 is supplied to the final STTD application determination unit 86.

  In addition, in the mobile communication terminal 15 of the present embodiment, when the determination result by the first determination unit 34 is supplied to the final STTD application determination unit 86, the determination result from the second determination unit 84 described later is obtained. Even if the final STTD application determination unit 86 has not yet been supplied, the final STTD application determination unit 86 supplies the determination result of the first determination unit 34 to the control unit 50 as a temporary determination result of the final determination result. (Step S160).

  As a result, when the first common control physical channel P-CCPCH is applied with STTD, the control unit 50 despreads the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40. Is supplied to the selection unit 60 (step S170). When STTD is not applied, the input supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 is supplied to the selection unit 60. Regardless of the despread output of the signal, a control signal for outputting “0” to the STTD decoding unit 70 is supplied to the selection unit 60 (step S171).

  Then, in the mobile communication terminal 15 of the present embodiment, the P-CCPCH demodulation unit 40 uses the scrambling code obtained in step S140 to transmit the first common control physical channel P-CCPCH transmitted from the base station. Demodulation is performed (step S180).

  Here, the despreading unit 42 of the P-CCPCH demodulation unit 40 uses the scrambling code to complex despread the slot of the first common control physical channel P-CCPCH transmitted from the base station first transmission antenna. Then, a signal obtained by integrating the one symbol interval is supplied to the STTD decoding unit 80. Further, the despreading unit 44 of the P-CCPCH demodulation unit 40 uses the scrambling code to complex despread the slot of the first common control physical channel P-CCPCH transmitted from the base station second transmission antenna, A signal obtained by integrating the one symbol interval is supplied to the selection unit 60.

  At this time, in mobile communication terminal 15, as described above, control unit 50 is based on the STTD application determination result by final STTD application determination unit 86 based only on the presence / absence of transmission from the base station second transmission antenna (step S160). ), A control signal is supplied to the selection unit 60, and the output of the despreading unit 44 of the P-CCPCH demodulation unit 40 is supplied to the STTD decoding unit 70 (steps S170 and S171).

  As a result, in the selection unit 60, when the provisional determination result regarding STTD application / non-application of the first common control physical channel P-CCPCH is STTD application (step S160), the despreading unit 44 of the P-CCPCH demodulation unit 40 The despread output of the input signal supplied to the selection unit 60 is supplied from the selection unit 60 to the STTD decoding unit 70 as it is (step S170). When STTD is not applied (step S160), the P-CCPCH demodulation unit Regardless of the despread output of the input signal supplied from the 40 despreading units 44 to the selection unit 60, the output “0” is output to the STTD decoding unit 70 and the input signal supplied from the despreading unit 44 to the selection unit 60 is output. It is supplied instead of the despread output (step S171).

  When the despread output of the despreading unit 44 of the P-CCPCH demodulating unit 40 is supplied via the selection unit 60 according to the input supplied from the selection unit 60, the STTD decoding unit 70 The first common control physical channel P to which STTD is applied by performing STTD decoding processing based on the despread output supplied from the despreader 42 of the CCPCH demodulator 40 and the despread output supplied from the despreader 44. -When the CCPCH is demodulated and "0" is supplied instead of the despread output supplied from the despreader 44 from the selector 60, the result is the same as in the case where STTD decoding is not performed. -Based on only the despread output supplied from the despreading unit 42 of the CCPCH demodulation unit 40, the demodulation process of the first common control physical channel P-CCPCH is performed without performing the STTD decoding process. Cormorant (step S180).

  Thus, according to W-CDMA mobile communication terminal 15 of the present embodiment, demodulation of first common control physical channel P-CCPCH according to STTD application / non-application of first common control physical channel P-CCPCH. Regarding the processing, as described above, without waiting for the demodulation of the synchronization channel SCH, after identifying the scrambling code of the base station in the third step of the three-step cell search method shown in step S140, immediately, in accordance with step S180. Demodulation processing of the first common control physical channel P-CCPCH can be started.

  On the other hand, in the W-CDMA mobile communication terminal 15 of the present embodiment, after identifying the scrambling code of the base station in the third step of the three-step cell search method shown in step S140, the identified scrambling code A determination process (step S181) for demodulating data (synchronization information) modulated on the synchronization channel SCH using the ring code to determine STTD application / non-application of the first common control physical channel P-CCPCH, It is executed in parallel with the demodulation processing of the first common control physical channel P-CCPCH shown in step S180 described above.

  That is, in the mobile communication terminal 15, as the determination process shown in step S181, the SCH demodulator 82 uses the scrambling code obtained in step S140 to transmit the first synchronization channel P-SCH transmitted from the base station. Demodulate the modulated data. Then, the second determination unit 84 determines whether STTD is applied to the first common control physical channel P-CCPCH based on the demodulated data modulated on the first synchronization channel P-SCH. The determination result is supplied to the final STTD application determination unit 86.

  As a result, the final STTD application determination unit 86 supplies the final STTD application determination unit 86 with the STTD application / non-application determination result of the first common control physical channel P-CCPCH by the second determination unit 84 by the process of step S181. Then, the final STTD application determination unit 86 uses the first common based on the determination result by the first determination unit 34 that has already been supplied and the determination result by the second determination unit 84 that has been newly supplied. It is finally determined whether STTD is applied to the control physical channel P-CCPCH (step S182).

  FIG. 10 shows a state in which the final STTD application determining unit in the W-CDMA mobile communication terminal according to the present embodiment finally determines whether STTD is applied to the first common control physical channel P-CCPCH. It is a table.

  As shown in FIG. 10, the final STTD application determination unit 86 determines the STTD application determination based on the presence / absence of transmission from the base station second transmission antenna that has already been supplied by the process of step S150 described above, and the newly supplied synchronization. If both STTD application determination from the demodulated data of the channel SCH is determined to be STTD application, STTD application processing is performed. Conversely, if both determine that STTD is not applied, processing of STTD non-application is performed.

  When the STTD application determination based on the presence / absence of transmission from the base station second transmission antenna and the STTD application determination from the demodulated data of the synchronization channel SCH give different results, the newly supplied synchronization channel SCH The final STTD application determination unit 86 gives priority to the STTD application / non-application determination result from the demodulated data over the STTD application / non-application determination result based on the presence / absence of transmission from the already supplied base station second transmission antenna. Performs STTD application determination.

  Thereby, in the mobile communication terminal 15, the control unit 50 sends a control signal to the selection unit 60 based on the final STTD application / non-application final, that is, the latest determination processing result by the final STTD application determination unit 86 (step S200). (Steps S210 and S211).

  Specifically, when the determination result of STTD application / non-application based on the presence / absence of transmission from the base station second transmission antenna is the same as the determination result of STTD application / non-application from the demodulated data of the synchronization channel SCH The final STTD application determination unit 86 continues to supply the provisional final determination result based on the determination result by the first determination unit 34 to the control unit 50 as the final determination result. On the other hand, if the STTD application / non-application determination result based on the presence / absence of transmission from the base station second transmission antenna is different from the STTD application / non-application determination result from the demodulated data of the synchronization channel SCH, The STTD application determination unit 86, instead of supplying the temporary determination result based on the determination result by the first determination unit 34 to the control unit 50 as the final determination result, the final determination based on the determination result by the second determination unit 84 Supply results.

  Thereby, when the first common control physical channel P-CCPCH is applied to STTD, the control unit 50 directly uses the despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 as the STTD decoding unit. 70 is supplied to the selection unit 60 (step S210). When STTD is not applied, the despread output of the input signal supplied from the despreading unit 44 of the P-CCPCH demodulation unit 40 Regardless of whether the control signal for outputting “0” to the STTD decoding unit 70 is supplied to the selection unit 60 (step S211).

  When the despread output of the despreading unit 44 of the P-CCPCH demodulating unit 40 is supplied via the selection unit 60 according to the input supplied from the selection unit 60, the STTD decoding unit 70 The first common control physical channel P to which STTD is applied by performing STTD decoding processing based on the despread output supplied from the despreader 42 of the CCPCH demodulator 40 and the despread output supplied from the despreader 44. -When the CCPCH is demodulated and "0" is supplied instead of the despread output supplied from the despreader 44 from the selector 60, the result is the same as in the case where STTD decoding is not performed. -Based on only the despread output supplied from the despreading unit 42 of the CCPCH demodulation unit 40, the demodulation process of the first common control physical channel P-CCPCH is performed without performing the STTD decoding process. Cormorant (step S220).

  Next, the operation and effect of the mobile communication terminal 15 configured as described above and the STTD application determination method applied to the mobile communication terminal 15 are shown in, for example, step S181 described above. The case will be described assuming that the STTD application determination process of the first common control physical channel P-CCPCH by the demodulation process of the synchronization channel SCH requires only 10 msec as one frame demodulation time.

  In this case, based on the provisional final determination result of STTD application / non-application based on the presence / absence of transmission from the base station second transmission antenna shown in step S150, it is shown in step S180 performed simultaneously with the demodulation processing of the synchronization channel SCH. The section of the demodulation process of the first common control physical channel P-CCPCH is 10 msec.

  From this, the final determination result of STTD application / non-application in step S182 according to the final determination result of the STTD application determination process by the demodulation process of the synchronization channel SCH shown in step S181 is shown in the above-described step S150. If it is the same as the STTD application / non-application determination result based on the presence / absence of transmission from the base station second transmission antenna, the selection unit 60 to the STTD decoding unit 70 also by the STTD application setting process shown in steps S200 to S211. No change occurs in the input supply control. Therefore, the demodulation process of the first common control physical channel P-CCPCH shown in step S180 is continued in the demodulation process of the first common control physical channel P-CCPH shown in step S220 and is substantially continued. Will be done.

  Therefore, the first common control channel P-CCPCH is demodulated using the scrambling code acquired in the third step of the above-described three-stage cell search method, and the acquired scrambling code is confirmed by the cyclic redundancy check CRC. Even when it is necessary to perform demodulation of the first common control channel P-CCPCH for x frames for the cyclic redundancy check CRC, the mobile communication terminal 15 or STTD of the present embodiment According to the application determination method, since the demodulation process of the synchronization channel SCH and the demodulation process of the first common control channel P-CCPCH are performed in parallel, the time required for the demodulation process of the synchronization channel SCH described above is 10 msec (that is, 1 Frame demodulation time) can be shortened from the total processing time.

  For example, when only confirming that the cyclic redundancy check CRC is OK, assume that a cyclic redundancy check CRC is added every 20 msec (every two frames), and then the cyclic redundancy check CRC is checked. In consideration of the case where the start frame is shifted, the demodulating process of the first common control channel P-CCPCH for a total of 30 msec (x = 3 frames) is necessary. Conventionally, the demodulating process of the synchronization channel SCH (10 msec) ) Followed by demodulation processing (30 msec) of the first common control channel P-CCPCH, a total processing time of 40 msec is required. However, according to the mobile communication terminal 15 or the STTD application determination method of the present embodiment, the synchronization channel SCH demodulation processing and the first common control channel P-CCPCH demodulation processing are performed in parallel. Since the time required for demodulating the channel SCH can be reduced by 10 msec, the total processing time is 30 msec. The specific shortening of the demodulation processing time of the first common control channel P-CCPCH is the same as in the case of the fourth embodiment.

  Thus, according to the mobile communication terminal 15 and the STTD application determination method of the present embodiment, the first common control physical channel P-CCPCH corresponding to STTD application / non-application of the first common control physical channel P-CCPCH. The STTD application determination based on the presence / absence of transmission from the base station second transmission antenna and the STTD application determination from the demodulated data of the synchronization channel SCH are used for the demodulation processing of the base station, and the final STTD application is determined from the result of each STTD application determination. Since the determination unit 86 performs provisional determination and final determination of STTD application / non-application of the first common control physical channel P-CCPCH, it is possible to improve the determination accuracy and consequently improve the total PCCPCH demodulation performance. be able to.

  Then, the demodulation processing of the first common control physical channel P-CCPCH according to the STTD application / non-application of the first common control physical channel P-CCPCH is performed from the total demodulation processing time of the first common control physical channel P-CCPCH. The time spent for demodulating the synchronization channel SCH can be shortened, and the STTD application / non-application determination of the first common control physical channel P-CCPCH is processed in parallel with the scrambling code identification. Therefore, the hardware scale can be reduced.

  In describing the W-CDMA mobile communication terminals 14 and 15 of the fourth and fifth embodiments described above, it is determined whether or not there is transmission using the second antenna of the base station. As a configuration for determining whether STTD is applied or not applied to the common control physical channel transmitted from the station, the first and second level measurement units 22 and 24, the calculation unit 32, and the first determination unit 34 are provided. Although described as a configuration, the configuration in which the second level measurement unit 24 and the calculation unit 32 are not provided, unlike the W-CDMA mobile communication terminal 11 of the first embodiment, The embodiment can be applied.

  Further, the state table for finally determining whether STTD is applied to the first common control physical channel P-CCPCH shown in FIG. 8 and FIG. 10 is the W-CDMA of the fourth embodiment. It is also possible to use the status table shown in FIG. 10 for the mobile communication terminal 14 and the status table shown in FIG. 8 for the W-CDMA mobile communication terminal 15 of the fifth embodiment.

It is a principal part block diagram of the mobile communication terminal for W-CDMA using the STTD application determination method by the 1st Embodiment of this invention. It is a graph which shows the probability distribution of the data used as the reference | standard for determining the presence or absence of the transmission output from a base station 2nd transmission antenna. It is a flowchart of the demodulation process of the 1st common control physical channel P-CCPCH by the mobile communication terminal for W-CDMA of 1st Embodiment. It is a principal part block diagram of the mobile communication terminal for W-CDMA using the STTD application determination method by the 2nd Embodiment of this invention. It is a graph which shows the probability distribution of the data used as the reference | standard for determining the presence or absence of the transmission output from a base station 2nd transmission antenna. It is a principal part block diagram of the mobile communication terminal for W-CDMA using the STTD application determination method by the 4th Embodiment of this invention. It is a flowchart of the demodulation process of the 1st common control physical channel P-CCPCH by the mobile communication terminal for W-CDMA of 4th Embodiment. FIG. 7 is a state table for finally determining whether or not STTD is applied to the first common control physical channel P-CCPCH in the W-CDMA mobile communication terminal according to the fourth embodiment. is there. It is a flowchart of the demodulation process of the 1st common control physical channel P-CCPCH by the mobile communication terminal for W-CDMA of 5th Embodiment. FIG. 10 is a state table for finally determining whether or not STTD is applied to the first common control physical channel P-CCPCH in the W-CDMA mobile communication terminal according to the fifth embodiment. is there. It is the table | surface which put together the application of the transmission diversity mode regarding a downlink physical channel type. It is explanatory drawing of the SCH demodulation method by the conventional receiver.

Explanation of symbols

11, 12, 13, 14, 15 Mobile communication terminal 20 Level measurement unit 22 First level measurement unit 23 Second level measurement unit 30 determination unit, first determination unit 32 calculation unit 40 P-CCPCH demodulation unit 42 44 Despreading unit 50 Control unit 60 Selection unit 70 STTD decoding unit 82 SCH demodulation unit 84 Second determination unit 86 Final STTD application determination unit
DESCRIPTION OF SYMBOLS 100 Receiver 110,120 Pilot channel receiving part 130 Synchronization channel receiving part 140 Selection part 150 Control part 160 Complex conjugate arithmetic part

Claims (16)

Data modulated by applying STTD to a common control physical channel transmitted from a base station equipped with a plurality of transmission antennas in spread spectrum communication and applying the TSTD from the base station to a synchronization channel that is also transmitted Or a STTD application determination method used in a mobile communication terminal used in a radio communication system of a method informed by an upper layer,
A measuring step of measuring the received field strength of the common pilot channel transmitted from the second antenna of the base station;
Based on the received electric field strength of the common pilot channel from the second antenna of the base station acquired by the measurement step, the presence or absence of transmission using the second antenna of the base station is determined and transmitted from the base station. A determination step of determining whether STTD is applied or not applied to the common control physical channel. In the determination step, the reception electric field strength of the common pilot channel from the second antenna of the base station acquired in the measurement step is compared with a threshold value, and the presence / absence of transmission using the second antenna of the base station The STTD application determination method according to claim 1, wherein: A preparatory measuring step of measuring the received field strength of the common pilot channel transmitted from the first antenna of the base station;
The method further comprises a threshold calculation step of calculating a threshold used in the determination step based on a received electric field strength of a common pilot channel from the first antenna of the base station acquired by the preparation measurement step. 2. The STTD application determination method according to 2. 4. The STTD according to claim 3, wherein the threshold value calculating step calculates the threshold value used in the determining step by using an offset that lowers the probability of determining that the STTD is not applied in the determining step. Application judgment method. 5. The STTD application determination method according to claim 1, wherein the measurement step and the determination step are performed in parallel with a base station scrambling code identification process in spread spectrum communication. Data modulated by applying STTD to a common control physical channel transmitted from a base station equipped with a plurality of transmission antennas in spread spectrum communication and applying the TSTD from the base station to a synchronization channel that is also transmitted Or a mobile communication terminal used in a radio communication system of a method informed by an upper layer,
Measuring means for measuring the received field strength of the common pilot channel transmitted from the second antenna of the base station;
Comparing the received electric field strength of the common pilot channel from the second antenna of the base station obtained by the measuring means with a threshold value to determine the presence or absence of transmission using the second antenna of the base station; Determining means for determining application / non-application of STTD to the common control physical channel transmitted from
Common control physical channel demodulation means for STTD decoding a common control physical channel transmitted by applying STTD from a base station;
A mobile communication terminal comprising: control means for controlling validity / invalidity of STTD decoding of a common control physical channel by the common control physical channel demodulation means in correspondence with a judgment result of the judgment means. Data modulated by applying STTD to a common control physical channel transmitted from a base station equipped with a plurality of transmission antennas in spread spectrum communication and applying the TSTD from the base station to a synchronization channel that is also transmitted Or a mobile communication terminal used in a radio communication system of a method informed by an upper layer,
Preparatory measurement means for measuring the received field strength of the common pilot channel transmitted from the first antenna of the base station;
Calculating a threshold value for determining the presence / absence of transmission using the second antenna of the base station based on the received electric field strength of the common pilot channel from the first antenna of the base station acquired by the preparation measurement means Threshold calculating means for measuring, measuring means for measuring the received electric field strength of the common pilot channel transmitted from the second antenna of the base station,
Transmission using the second antenna of the base station by comparing the received electric field strength of the common pilot channel from the second antenna of the base station obtained by the measuring means with the threshold obtained by the threshold calculating means Determining means for determining whether or not STTD is applied to the common control physical channel transmitted from the base station;
Common control physical channel demodulation means for STTD decoding a common control physical channel transmitted by applying STTD from a base station;
A mobile communication terminal comprising: control means for controlling validity / invalidity of STTD decoding of a common control physical channel by the common control physical channel demodulation means in correspondence with a judgment result of the judgment means. The threshold calculation means has an offset that lowers the probability of determining that STTD is not applied when calculating a threshold for determining the presence or absence of transmission using the second antenna of the base station. The mobile communication terminal according to claim 7. The mobile communication terminal according to any one of claims 6 to 8, wherein the measurement unit and the determination unit operate in parallel with a base station scrambling code identification process in spread spectrum communication. Data modulated by applying STTD to a common control physical channel transmitted from a base station equipped with a plurality of transmission antennas in spread spectrum communication and applying the TSTD from the base station to a synchronization channel that is also transmitted Or a mobile communication terminal used in a radio communication system of a method informed by an upper layer,
Measuring means for measuring the received field strength of the common pilot channel transmitted from the second antenna of the base station;
Comparing the received electric field strength of the common pilot channel from the second antenna of the base station obtained by the measuring means with a threshold value to determine the presence or absence of transmission using the second antenna of the base station; First determination means for determining application / non-application of STTD to the common control physical channel transmitted from
Synchronization channel demodulation means for demodulating a synchronization channel that is also transmitted by applying TSTD from the base station;
Second determination means for determining application / non-application of STTD to the common control physical channel transmitted from the base station, from data modulated on the synchronization channel demodulated by the synchronization channel demodulation means;
Final determination means for determining application / non-application of STTD to the common control physical channel transmitted from the base station from the determination result by the first determination means and the determination result by the second determination means;
Common control physical channel demodulation means for STTD decoding a common control physical channel transmitted by applying STTD from a base station;
A mobile communication terminal comprising: control means for controlling validity / invalidity of STTD decoding of the common control physical channel by the common control physical channel demodulation means in correspondence with the judgment result of the final judgment means. Data modulated by applying STTD to a common control physical channel transmitted from a base station equipped with a plurality of transmission antennas in spread spectrum communication and applying the TSTD from the base station to a synchronization channel that is also transmitted Or a mobile communication terminal used in a radio communication system of a method informed by an upper layer,
Preparatory measurement means for measuring the received field strength of the common pilot channel transmitted from the first antenna of the base station;
Calculating a threshold value for determining the presence / absence of transmission using the second antenna of the base station based on the received electric field strength of the common pilot channel from the first antenna of the base station acquired by the preparation measurement means Threshold calculation means for
Measuring means for measuring the received field strength of the common pilot channel transmitted from the second antenna of the base station;
Transmission using the second antenna of the base station by comparing the received electric field strength of the common pilot channel from the second antenna of the base station obtained by the measuring means with the threshold obtained by the threshold calculating means First determination means for determining whether or not STTD is applied to the common control physical channel transmitted from the base station;
Synchronization channel demodulation means for demodulating a synchronization channel that is also transmitted by applying TSTD from the base station;
Second determination means for determining application / non-application of STTD to the common control physical channel transmitted from the base station, from data modulated on the synchronization channel demodulated by the synchronization channel demodulation means;
Final determination means for determining application / non-application of STTD to the common control physical channel transmitted from the base station from the determination result by the first determination means and the determination result by the second determination means;
Common control physical channel demodulation means for STTD decoding a common control physical channel transmitted by applying STTD from a base station;
A mobile communication terminal comprising: control means for controlling validity / invalidity of STTD decoding of the common control physical channel by the common control physical channel demodulation means in correspondence with the judgment result of the final judgment means. The threshold calculation means has an offset that lowers the probability of determining that STTD is not applied when calculating a threshold for determining the presence or absence of transmission using the second antenna of the base station. The mobile communication terminal according to claim 11. The final determination means is transmitted from the base station by the first determination means before determining whether STTD is applied or not applied to the common control physical channel transmitted from the base station by the second determination means. The determination result of application / non-application of STTD to the common control physical channel is supplied to the control unit, and after the determination by the second determination unit, the determination result by the first determination unit is replaced with the determination result The mobile communication terminal according to claim 10, wherein the determination result by the second determination unit is supplied to the control unit. The final determination means is transmitted from the base station by the first determination means before determining whether STTD is applied or not applied to the common control physical channel transmitted from the base station by the second determination means. The determination result of application / non-application of STTD to the common control physical channel is supplied to the control unit, and after the determination by the second determination unit, the determination result by the first determination unit and the second determination unit A new determination result of STTD application / non-application to the common control physical channel based on the combination with the determination result by the determination unit is acquired, and the acquisition is performed instead of the determination result by the first determination unit The mobile communication terminal according to claim 10, wherein the new determination result is supplied to the control means. After the determination by the second determination unit, the final determination unit determines that either determination is STTD application based on the determination result by the first determination unit and the determination result by the second determination unit. In this case, the mobile communication terminal according to claim 14, wherein a determination result indicating that STTD is applied is supplied to the control means instead of the determination result by the first determination means. The mobile communication terminal according to any one of claims 10 to 15, wherein the measurement unit and the first determination unit operate in parallel with a base station scrambling code identification process in spread spectrum communication.

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