JP4613646B2 - Portable terminal and antenna switching control method in portable terminal - Google Patents

Description

  The present invention relates to mobile terminal communication for performing communication using a plurality of antennas provided in a mobile terminal and an antenna switching control method in the mobile terminal.

  Recently, a W-CDMA (Wideband-Code Division Multiple Access) system has been proposed as a portable terminal used in a communication system. This W-CDMA system has been proposed as a communication system for third-generation mobile phones. The CDMA system is a communication system with high frequency efficiency because one frequency can be shared by a plurality of users.

  This W-CDMA system has the ability to transmit data at 144 kbps when moving at high speed, 384 kbps when walking, and 2 Mbps when stationary, enabling real-time communication with video and audio, and using multiple antennas to improve communication quality A portable terminal equipped is proposed. This type of mobile terminal can select an antenna with a high reception level and avoid communication failure (for example, loss of communication data) that occurs when the reception level of the antenna deteriorates. Also, in this type of mobile terminal, if efficient antenna switching can be performed, there is an advantage from the viewpoint of current consumption over reception diversity in which simultaneous communication is performed using a plurality of antennas.

  Japanese Patent Application Laid-Open Nos. 2001-274732 and 2003-298498 disclose techniques for switching a plurality of antennas provided in a mobile phone. The technique disclosed in Japanese Patent Application Laid-Open No. 2001-24732 selects an antenna having a good wireless state based on the reception quality of the antenna. In the technique disclosed in Japanese Patent Laid-Open No. 2003-298498, dedicated channel communication quality is estimated, and an antenna is selected based on the estimated communication quality.

  In a mobile terminal using the antenna switching technology described above, switching of a plurality of antennas can be performed in a standby state in which only communication information and an incoming signal are received, not in bidirectional communication, or in bidirectional communication but with a small amount of data. It is mainly used in a common channel communication state that shares a communication channel with other users.

  The main reason for this is that there are many cases in which a large amount of data is flowing or there is a continuous flow of data in communication on an individual channel where a user occupies a certain wireless line and performs bidirectional communication. It is conceivable that the timing for switching the antennas becomes more difficult without losing. In addition, in communication on individual channels, users occupy and use wireless lines, so high-speed power control for each user (controlling only individual channel power) can be applied, and high-speed improvements in communication quality have been attempted. Yes.

  Even if such a situation is considered, under the situation where the reception level and communication quality are significantly deteriorated, it is unlikely that communication data is normally transmitted and received, and the advantage of improving the reception level by switching antennas is sufficient. It is in. For example, if the communication quality deteriorates due to a voice call or a TV (television) telephone call, there is a possibility that the voice or image is interrupted, and in the worst case, the call is lost (communication disconnection). In the case of a call loss, if the received electric field level improves within a certain period of time, it is possible to continue communication by performing a reconnection operation. In the case of silence etc.).

  Even with the technology disclosed in the above-mentioned patent document, there is a problem that it is difficult to switch antennas without losing data when a large amount of data is flowing or when data is constantly flowing. is there.

JP 2001-274732 A JP 2003-298498 A

  An object of the present invention is to provide a portable terminal and an antenna switching control method for switching antennas in synchronization with data transmission on a transmission channel allocated for data communication and realizing antenna switching according to the use environment. It is to provide.

In order to achieve the object, a mobile terminal according to the present invention includes a plurality of antennas, and performs communication using a data transmission channel allocated for data communication.
A level determination unit for determining a received electric field level by the antenna;
A synchronization determination unit for determining data for synchronization with data transmission by the data transmission channel;
A switching unit configured to switch the plurality of antennas in synchronization with data transmission on the data transmission channel based on determination results output from the level determination unit and the synchronization determination unit. It is what.

  In the present invention, the reception electric field level by the antenna is determined, and further data for synchronization with the data transmission by the data transmission channel is determined. Next, based on the determination result, the plurality of antennas are switched in synchronization with the data transmission on the data transmission channel.

  Therefore, according to the present invention, antenna switching can be performed in synchronization with data transmission on a transmission channel assigned for data communication, and antenna switching according to the use environment can be realized.

  In the present invention, the amount of transmission data transmitted on the data transmission channel may be determined as data for synchronization with data transmission through the data transmission channel. Furthermore, the deterioration of communication quality received by the antenna may be determined as data for synchronization with data transmission through the data transmission channel. Further, as data for synchronization with data transmission through the data transmission channel, the amount of transmission data transmitted on the data transmission channel and the deterioration of communication quality received by the antenna may be determined. It ’s good. In this case, it is desirable to perform antenna switching giving priority to the deterioration of communication quality received by the antenna.

  Further, the antenna may be switched by stepwise determining the amount of transmission data transmitted on the data transmission channel and the deterioration in communication quality received by the antenna.

  As described above, according to the present invention, data transmission on a data transmission channel can be performed according to a combination of a received electric field level, a received communication quality (error level), and a transmission data amount with respect to antenna switching during individual channel communication in a mobile terminal. The antenna can be switched in synchronization with each other, the antenna switching according to the use environment can be realized, the antenna can be switched actively before call loss, and the communication maintenance rate in the individual channel communication can be improved.

  Further, antenna switching in a stepwise state is performed by determining a combination of a received electric field level, a received communication quality (error level), and a transmission data amount regarding antenna switching during communication by a data transmission channel in a portable terminal. be able to.

  For example, when the amount of transmission data is small, the effect of antenna switching is small. Therefore, by switching antennas at an early stage when the reception communication quality starts to deteriorate, the final call loss is prevented and dedicated channel communication is performed. The communication maintenance rate can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The embodiment of the present invention realizes antenna switching according to the use environment by switching antenna switching during individual channel communication in a stepwise state of reception error level and transmission data amount in a W-CDMA mobile phone terminal. It is characterized by doing.

  In FIG. 1, a mobile terminal according to an embodiment of the present invention is a W-CDMA mobile terminal, and includes an application control unit 1, a communication control unit 2, a signal processing unit 3, an antenna switching unit 4, and a plurality of mobile terminals. (In the embodiment, two antennas) 51 and 52 are provided.

  The application control unit 1 has a function of controlling applications and transmitting / receiving user data (voice data, videophone data, packet data, etc.) to and from the communication control unit 2. Specifically, the application control unit 1 processes transmission data to be transmitted, outputs the processed data to the communication control unit 2, processes the reception data output from the communication control unit 2, and reproduces the data. It has a function of outputting later data to a player (not shown). A player (not shown) displays the packet data from the application control unit 1 on the screen, outputs the audio data as an audible sound, and displays the video data as a visible video on the screen. The video data includes still data and moving image data.

  Here, a standard of a radio access interface formed between a base station and a mobile terminal as a mobile station in the W-CDMA system will be described. Data transmission between the base station and the portable terminal is performed via a wireless interface. The protocol architecture of this wireless interface is composed of a protocol layer of a physical layer, a data ring layer, and a network layer.

  Here, the physical layer defines physical specifications such as electrical characteristics flowing through the network such as data voltage, waveform, and modulation method. The data ring layer builds functions for connecting mobile terminals connected to the same network, such as recognition of a destination, a source, a boundary of continuous data, and control of data errors. The network layer constructs a function of interconnecting portable terminals across a plurality of networks having different data sizes, addressees, source addresses, and different specifications.

  The channel configuration in the radio interface has a three-layer channel configuration of a transport channel, a physical channel, and a logical channel in order to flexibly support various service provision forms and multicalls. The transport channel is a channel provided from the physical layer to the data ring layer, and a plurality of types of transport channels are prepared for transmitting data having different characteristics and transmission forms on the physical layer. Yes. The logical channel performs communication between RLC (Radio Link Control) and MAC (Medium Access Control) included in the network layer. The physical channel performs communication between the physical layer and the base station, and between the base station and the mobile terminal. The physical channels include DPCH (Dedicated Physical Channel), DPCCH (Dedicated Physical Control Channel), PRACH (Physical Random Access Channel), PCPCH (Physical Common Packet Channel), CPICH (Common Pilot Channel), and P-CCPCH (Primary Common Control). Physical Channel), S-CCPCH (Secondary Common Control Physical Channel), SCH (Synchronization Channel), PDSCH (Physical Downlink Shared Channel), AICH (Acquisition Indication Channel), PICH (Page Indication Channel), AP-AICH (Access Preamble Acquisition) It includes various channels such as Indicator Channel), CD / CA-ICH (CPCH Collision Detection / Channel Assignment Indicator Channel), and CSICH (CPCH Status Indicator Channel).

  The DPCH is an uplink / downlink bidirectional channel and is individually assigned to a mobile terminal. Only one DPCCH is allocated to a mobile terminal using the DPCH, and is a channel for DPCH physical layer control. The PRACH is an uplink common channel and is used for data transmission from an upper layer, particularly for low-rate data transmission. The PCPCH is an upstream common channel and is used for packet data communication, particularly for high-rate data transmission. The CPICH is a downlink common channel and is used for channel estimation of the downlink channel, cell search of the mobile terminal, timing reference of other downlink physical channels in the same cell, and the like. The P-CCPCH is a downlink common channel, and exists in each cell and is used to transmit broadcast information. The S-CCPCH is a downlink common channel, which may exist in each cell, and is used for data transmission from a paging signal and higher layers, particularly for low-rate data communication. It is. The SCH is a downlink common channel, one in each cell, and is used for cell search of the mobile terminal. The PDSCH is a downlink common channel and may exist in plural in each cell, and is used for packet data transmission, particularly for high rate data communication. The AICH is a downlink common channel, exists in a pair with the PRACH, and is used for random access control of the PRACH. The PICH is a downlink common channel, exists in a pair with the S-CCPCH to which a paging signal is mapped, and transmits presence / absence of incoming call information for each incoming call group. The AP-AICH is a downlink common channel, exists in pairs with the PCPCH, and is used for random access control of the PCPCH. The CD / CA-ICH is a downlink common channel, exists in pairs with the PCPCH, and is used for collision control of the PCPCH. The CSICH is a downlink common channel, and is associated with the AP-AICH and transmits information related to the communication state of the PCPCH.

  The mobile terminal according to the embodiment of the present invention performs data communication using the DPCH assigned to each mobile terminal as an individual channel and the PCPCH and the PDSCH as uplink / downlink common channels. . The dedicated channel and the common channel used in the following description correspond to the above channels. The dedicated channel functions as a data transmission channel assigned for data communication in the W-CDMA system.

  The communication control unit 2 includes a transmission unit 22, a data amount determination unit 23, a reception unit 25, a quality determination unit 24, and a switching control unit 21.

  The transmission unit 22 of the communication control unit 2 has a function of sending the transmission data processed by the application control unit 1 to the transmission processing unit 31 of the signal processing unit 3 and controlling the transmission processing of the transmission processing unit 31. .

  The data amount determination unit 23 of the communication control unit 2 has a function of determining the data amount of transmission data transmitted from the transmission unit 22 to the transmission processing unit 31 and outputting a determination signal indicating the determination result to the switching control unit 21. ing.

  The reception unit 25 of the communication control unit 2 has a function of outputting the demodulated reception data output from the reception processing unit 32 of the signal processing unit 3 to the application control unit 1.

  The quality determination unit 24 of the communication control unit 2 receives the reception data demodulated by the reception processing unit 32 of the signal processing unit 3, monitors this reception data, monitors the communication quality of the reception data, A function of outputting a certain quality determination signal to the switching control unit 21 is provided. Here, the quality determination unit 24 measures the error rate of the reception data received on the dedicated channel, and determines the quality of the communication quality of the received signal. The error rate of the received data is BLER (Block Error Rate), BER (Bit Error Rate), etc., and these error rates are monitored to determine the communication quality.

  The switching control unit 21 of the communication control unit 2 receives the determination signal from the data amount determination unit 23 and the quality determination signal from the quality determination unit 24, and performs antenna switching by the antenna switching unit 4 based on these signals. It has a function to control the start / stop of monitoring.

  The transmission processing unit 31 of the signal processing unit 3 modulates transmission data output from the transmission unit 22 with a carrier wave under the control of the transmission unit 22 of the communication control unit 2 and converts the modulated wave signal into the signal processing unit 3. The function of outputting to the transmission / reception switching device (Duplexer) 33 is provided.

  The reception processing unit 32 of the signal processing unit 3 receives the reception data output from the transmission / reception switch 33, demodulates the reception data, and outputs the demodulated reception data to the reception unit 25 of the communication control unit 2. It has a function. Further, the reception processing unit 32 measures the received electric field level such as RSSI (Received Signal Strength Indicator: total received power), RSCP (Received Signal Code Power: signal power in the common pilot channel (CPICH)) and the communication quality. And a function of outputting the measurement result to the quality judgment unit 24 of the communication control unit 2.

  The antenna switching unit 4 has a function of switching and selecting the two antennas 51 and 52 by using an antenna switching signal output from the switching control unit 21 of the communication control unit 2 as an input.

  Here, the level determination unit for determining the received electric field level by the antenna includes the reception processing unit 32 and the quality determination unit 24. A synchronization determination unit that determines data for synchronization with data transmission through a dedicated channel includes a reception processing unit 32, a quality determination unit 24, and a data amount determination unit 22. The synchronization determination unit includes at least a data amount of transmission data transmitted on the data transmission channel and deterioration of communication quality received by an antenna as data for synchronization with data transmission through the data transmission channel. Determine one. Based on the determination results output from the level determination unit and the synchronization determination unit, a switching unit that switches the plurality of antennas in synchronization with data transmission on the data transmission channel is a switching control unit 21. , The antenna switching unit 4.

  Next, an operation when data communication is performed using the mobile terminal according to the embodiment of the present invention will be described with reference to the drawings. In the following description of the operation, the reception processing unit 32, the quality determination unit 24, and the data determination unit 23 as a synchronization determination unit are transmitted on the dedicated channel as data for synchronization with data transmission through the dedicated channel. A case where the amount of transmission data to be transmitted and the deterioration of communication quality received by the antenna are determined will be described.

  In FIG. 1, it is assumed that a transmission signal from a base station is received by one antenna 51 among a plurality of antennas 51 and 52 provided in a mobile terminal. In this case, the antenna switching unit 4 inputs the reception data received by the antenna 51 to the transmission / reception switch 33. The transmission / reception switch 33 sends the reception data from the antenna switching unit 4 to the reception processing unit 32 of the signal processing unit 3.

  The reception processing unit 32 of the signal processing unit 3 demodulates the reception data from the transmission / reception switch 33 and outputs the demodulated reception data to the reception unit 25 of the communication control unit 2. Further, the reception processing unit 32 measures the electric field level of the received signal from the transmission / reception switch 33, measures the communication quality of the received signal before demodulation, and sends the measurement result to the quality judgment unit 24 of the communication control unit 2 and the switching. Output to the control unit 24.

"Startup flow for antenna switching operation"
Next, the antenna switching activation operation in the present invention will be described with reference to FIG.

  The switching control unit 21 of the communication control unit 2 receives the measured value data of the received electric field level from the reception processing unit 32 (step S1 in FIG. 2), and the measured value and the threshold value of the received electric field level stored in advance. Are compared (step S2 in FIG. 2).

  When the measured value is equal to or greater than the threshold value (NO in step S2), the switching control unit 21 notifies the quality determination unit 24 that antenna switching monitoring is stopped (step S3 in FIG. 2). Thereby, the switching control part 21 and the quality determination part 24 stop the operation | movement of antenna switching monitoring (step S4 of FIG. 2).

  When the measured value is equal to or smaller than the threshold value (YES in step S2), the switching control unit 21 is under a condition that the operation state of the control switching unit 21 itself is not activated (YES in step S5 in FIG. 2). ), Transition to the antenna switching monitoring activation state (step S6 in FIG. 2). In this transitioned state, the switching control unit 21 outputs an activation signal indicating that the switching control unit 21 has been activated to the quality determination unit 24 (step S7 in FIG. 2), and after outputting this signal, the quality determination unit 24 (Step S8 in FIG. 2).

  On the other hand, when the antenna switching monitoring is activated (step S5 in FIG. 2), the switching control unit 21 waits for a determination signal from the quality determination unit 24 (step S8 in FIG. 2).

"Operation while starting antenna switching monitoring"
Next, the operation during antenna switching monitoring activation will be described.

  Upon receiving the activation notification signal from the switching control unit 21, the quality determination unit 24 of the communication control unit 2 monitors the communication quality of the reception signal periodically output from the reception processing unit 32 of the signal control unit 3, When it is confirmed that the communication quality of the received signal for a certain period has deteriorated, a message to that effect is output to the switching control unit 21.

  FIG. 3 shows the determination operation when the communication quality of the received signal received by the antenna deteriorates. The quality determination unit 24 sets a plurality of threshold values indicating the degree of communication quality deterioration as a reference for determining the communication quality deterioration of the received signals received by the antennas 51 and 52. It has a number of phases.

  In the example shown in FIG. 3, the communication quality deterioration degree is divided into three phases. That is, in FIG. 3, the relationship of Phase1 <Phase2 <Phase3 is set according to the degree of communication quality degradation. This communication quality indicates the error rate of the data, and Phase 1, Phase 2 and Phase 3 are set corresponding to the error rate, and the error rate increases in the relationship of Phase 1 <Phase 2 <Phase 3.

  A case where the deterioration of communication quality is monitored will be described with reference to FIG. In the example shown in FIG. 3, the deterioration of the communication quality is determined step by step. The quality determination unit 24 monitors the communication quality reported from the reception processing unit 32. When the reported communication quality exceeds each threshold value, the quality judgment unit 24 starts a built-in timer corresponding to each threshold value. More specifically, the quality determination unit 24 starts a timer T1 corresponding to Phase 1 when the communication quality exceeds the threshold value of Phase 1. Thereafter, the quality determination unit 24 starts the corresponding timers T2 and T3 when the call quality exceeds the threshold values of Phase2 and Phase3, respectively. As for timer ON / OFF, in the case of timer T1, it starts at time A when the communication quality reaches Phase 1, and stops at time B when it shifts from Phase 1 to Phase 2 or falls below Phase 1 (communication quality is improved). To do. In the case of the timer T2, the communication quality starts when the communication quality reaches Phase 2, and stops at the time when the phase shifts from Phase 2 to Phase 3, or when the communication quality drops below Phase 2 (the communication quality is improved). In the case of the timer T3, it starts at time A when the communication quality reaches Phase 3, and stops at time B when the communication quality drops below Phase 3 (communication quality is improved). The time between the point A when the timer starts and the point B when it stops is set as the timer setting time. The set time of this timer is set in a range in which the two antennas 51 and 52 are switched to improve the communication maintenance rate.

  On the other hand, when the communication quality falls below the thresholds Phase1, Phase2, and Phase3 before the set time of the timer expires, that is, when the communication quality is improved, the quality determination unit 24 sets the timer T1 corresponding to the threshold. T2 and T3 are stopped respectively.

  In the communication quality situation as shown in FIG. 3, the quality determination unit 24 is a case where the communication quality deteriorates exceeding the threshold of Phase 3 and then falls below Phase 3, that is, the communication quality is improved, and the timer T3 expires the set time. Force stop before. In the communication quality situation shown in FIG. 3, the communication quality deteriorates exceeding the thresholds Phase1 and Phase2, respectively. However, since the quality is not improved within the set times of the timers T1 and T2, the quality determination unit 24 starts the timers T1 and T2. The timers T1 and T2 are stopped when the set time expires.

  Each time the quality judgment unit 24 exceeds the thresholds Phase1, Phase2, Phase3 and the communication quality is not improved within the set time of the timer, the timer T1, T2 or T3 stops after the set time has elapsed. In addition, the switching control unit 21 is notified of which timer has expired.

  The switching control unit 21 recognizes which timer T1, T2 or T3 reported from the quality determination unit 24 is, and grasps the degree of communication quality deterioration (Phase) based on the recognition. Since the timers T1, T2, and T3 are started in response to the communication quality deterioration threshold values, the switching control unit 21 performs communication when, for example, the timer to be reported is recognized as the timer T1. Ascertain that the degree of quality degradation exceeds the threshold Phase1. Even when the timers T2 and T3 are reported, the switching control unit 21 recognizes the timers T2 and T3 and grasps that the degree of deterioration of the communication quality exceeds the thresholds Phase2 and Phase3, respectively. After recognizing the degree of communication quality deterioration, the switching control unit 21 notifies the data amount determination unit 23 of a request for a data amount determination result.

  The data amount determination unit 23 determines the amount of data in the transmission unit 22 at the time when the request notification from the switching processing unit 21 is received, and notifies the switching control unit 21 of the result. FIG. 4 shows an example of the data flow in the transmission unit 22.

  As shown in FIG. 4, the transmission unit 22 includes a transmission control unit 221, a transmission buffer 222, and a transmission execution unit 223 as main components. Data from the upper layer (application control unit 1) side is input to the transmission control unit 221 of the transmission unit 22. The transmission control unit 221 processes the input data into different data for each call type, and stores the processed data in the transmission buffer 222. Here, the transmission data 1, 2, 3,... N-1, n stored in the transmission buffer 222 is data stored as one transmission in a communication call type (voice call, videophone call, packet call). The size is different.

  Further, the transmission control unit 221 turns on the transmission flag when data is stored in the transmission buffer 222, and thereafter monitors the presence or absence of data stored in the transmission buffer 222. When there is no data stored in the transmission buffer 222, the transmission control unit 221 sets the transmission flag to OFF.

  The transmission execution unit 223 refers to the transmission flag issued by the transmission control unit 221 at the transmission timing synchronized with the signal processing unit 3. If the transmission flag is ON, the transmission execution unit 223 transmits the transmission data in the transmission buffer 222 to the signal processing unit. 3 to send.

  The data amount determination unit 23 refers to the amount of data stored in the transmission buffer 222 of the transmission unit 22 when the request notification is received, and notifies the switching control unit 21 of the remaining data amount.

  The switching control unit 21 determines the antenna switching based on the remaining data amount notified from the data amount determining unit 23 and the communication quality deterioration condition reported from the quality determining unit 24.

  The switching control unit 21 includes a remaining data amount threshold (A, B, C, D, E, F) for each communication quality deterioration state (Phase) as shown in FIG. 5 (example of determination criterion). The switching control unit 21 shown in FIG. 5 has a function of determining in a stepwise manner the amount of transmission data and the deterioration of communication quality. The call type shown in FIG. 5 corresponds to the communication call type, and the call type is one of a voice call, a video phone call, and a packet call. The communication quality level corresponds to the thresholds Phase1, Phase2, and Phase3 in FIG. The remaining data amount thresholds are set such that A <B <C, D <E <F, and A <D. Note that the switching control unit 21 may have a function of determining at least one of transmission data amount and communication quality deterioration in a stepwise manner.

  First, the switching control unit 21 recognizes which timers T1, T2, and T3 are timers reported from the quality determination unit 24, and sets a threshold Phase corresponding to communication quality degradation based on the recognition information of the timers. to decide. For example, the threshold value determined by the switching control unit 21 is assumed to be Phase1. Next, the switching control unit 21 compares the remaining data amount reported from the data amount determining unit 23 with the remaining data amount threshold A corresponding to the determined threshold Phase1.

  When the remaining data amount is smaller than the remaining data amount threshold, the switching control unit 21 outputs an antenna switching command to the antenna switching unit 4. Conversely, when the remaining data amount is larger than the remaining data amount threshold, the switching control unit 21 continues the antenna switching monitoring without executing the antenna switching, and the next report from the quality judgment unit 24 (next timer expires). ).

  The data amount determination unit 21 determines the transmission data amount by comparing the remaining data amount with the threshold value, but compares the data amount of the entire transmission data amount transmitted from the transmission control unit 221 with the threshold value. The transmission data amount may be determined. In addition, the switching control unit 21 determines the antenna switching in consideration of the transmission data amount reported from the data amount determination unit 23 and the communication quality reported from the quality determination unit 24. It is not something that can be done. The switching control unit 21 may determine the antenna switching in consideration of one of the transmission data amount reported from the data amount determination unit 23 and the communication quality level reported from the quality determination unit 24. It ’s good.

  Whether switching is performed with priority on degradation of communication quality or switching is not performed with priority on the amount of data. The thresholds related to quality and timers (Phase, T) and corresponding remaining data thresholds (A, B, C, etc.) ). When the threshold Phase is made smaller or the timer T is made shorter, an antenna switching event occurs sensitively to communication quality deterioration, so that antenna switching can be performed more actively. In addition, by reducing the remaining data threshold, the antenna is switched only when the data amount is finally small in the determination unit, so that it is possible to perform antenna switching that places more importance on the data amount. In this way, antenna switching control can be performed with elements (quality, data amount) that should be emphasized depending on the relationship between each threshold and the timer.

  Further, as shown in FIG. 5, by enabling the threshold of the communication quality level and the threshold of the transmission data amount to be set independently for each communication call type, for example, when the communication call type is packet communication, there is no data section. Since there are many possibilities, it is possible to switch antennas depending on the type of communication call, such as making it easy to switch antennas and making switching difficult during videophone communications.

  The embodiment of the present invention compares the received electric field level at the antenna after antenna switching with the received electric field level at the antenna before antenna switching in the stage of performing the antenna switching operation. Decide whether to do it. An example of an operation flow at the time of performing antenna switching in the embodiment of the present invention will be described based on FIG. 6 (OK time) and FIG. 7 (NG time).

  When switching control unit 21 determines to perform antenna switching (step S60 in FIG. 6), it notifies an antenna switching command to transmission unit 22 and quality determination unit 24 (steps S61 and 62 in FIG. 6).

  The transmission unit 22 receives the antenna switching execution notification from the switching control unit 21 and turns off the transmission flag to stop transmission (step S63 in FIG. 6). If there is transmission data from the host (application control unit 1) while the transmission unit 22 stops transmission, the transmission data is stored in the transmission buffer 222 shown in FIG. If transmission data is output one after another even if it is stored in the transmission buffer 222, the transmission data stored in the transmission buffer 222 in order from the oldest is deleted.

  The quality determination unit 24 receives the antenna switching execution notification, stops all timers that are currently activated, and temporarily stops monitoring of communication quality (step S64 in FIG. 6). When the quality determination unit 24 stops the timer, it stores the measured values of all the timers that are activated.

  Next, the switching control unit 21 instructs the antenna switching unit 4 to switch the antenna (step S65 in FIG. 6). The antenna switching unit 4 switches one antenna 51 or 52 to the other antenna 52 or 51 in accordance with an instruction from the switching control unit 21 (step 66 in FIG. 6). After executing the antenna switching, the reception control unit 32 measures the received electric field level by the switched antenna (step 67 in FIG. 6), and reports the measurement result to the switching control unit 21 (step 68 in FIG. 6).

  The switching control unit 21 compares the received electric field level at the antenna before switching with the received electric field level at the antenna after switching (step S69 in FIG. 6), and the received electric field level at the antenna after switching is high. Then, the transmission unit 22 and the quality determination unit 24 are notified of the determination as OK (steps S70, S71, S72 in FIG. 6).

  Upon receiving the notification of determination OK, the transmission unit 22 turns on the transmission flag (step S73 in FIG. 6). The quality determination unit 24 clears the stored measurement value (step S74 in FIG. 6) and stops monitoring the communication quality. Thereafter, the switching control unit 21 stops the antenna switching monitoring (step S75 in FIG. 6).

  In the comparison of the received electric field level, when the received electric field level at the antenna after switching is low, the switching control unit 21 instructs the antenna switching unit 4 to switch the antenna again as a determination NG as shown in FIG. 7 (step S81). The antenna switching unit 4 switches the antennas 51 and 52 again in response to the switching command from the switching control unit 21 (step S82). Note that the processing in steps 76 to 80 in FIG. 7 is performed in the same manner as the processing in steps 60 to 64 in FIG.

  After executing the antenna switching, the reception control unit 32 measures the received electric field level by the switched antenna (step 83 in FIG. 7) and reports the measurement result to the switching control unit 21 (step 84 in FIG. 7).

  The switching control unit 21 compares the received electric field level at the antenna before switching with the received electric field level at the antenna after switching (step S85 in FIG. 7), and the received electric field level at the antenna after switching is low. Then, the determination unit NG notifies the antenna switching unit 4, the transmission unit 22, and the quality determination unit 24 (steps S86, S87, S88, and S89 in FIG. 7).

  The antenna switching unit 4 switches the antenna again based on the antenna switching command from the switching control unit 21 (step S90 in FIG. 7). Further, the transmission unit 22 receives the notification and sets the transmission flag to ON (step S91). The quality determination unit 24 starts all the timers holding the measurement values, and restarts monitoring of the communication quality from the held measurement values (step S92).

  The above operation realizes step-by-step antenna switching according to the use environment.

  The embodiment of the present invention is not limited to the above-described embodiment. When determining the transmission data amount by the transmission unit 22 described in the above-mentioned “operation during antenna switching monitoring activation”, a data transmission indicator is used instead of the method of referring to the remaining data amount in the transmission buffer 222 shown in FIG. The amount of transmission data may be determined by monitoring a TFCI (Transport Format Combination Indicator). In a W-CDMA system terminal, the transport channel provided from the lower layer of the protocol architecture of the radio interface differs depending on the communication call type. There are multiple transport formats for each transport channel, and the format of data such as bit size that can be transmitted is determined by this transport format. The TFCI indicates a combination of TFs provided from this lower layer and is changed at each transmission timing. By monitoring this, it is possible to grasp the data amount of transmission data actually transmitted from the lower layer.

  Therefore, the data amount determination unit 23 creates a transmission data amount table for each TFCI for all TFCIs that can be selected depending on the communication call type. During communication, the data amount determination unit 23 monitors the TFCI set by the transmission unit 22 and grasps the TFCI data specified from the created transmission data amount table. In this case, the data amount determination unit 23 calculates a moving average for a certain period T (can be set for each call type) with respect to the transmission data amount, and sets it as the average data amount. Then, the data amount determination unit 23 transmits the latest average data amount to the switching control unit 21 when the switching control unit 21 receives a request notification of the data amount determination result.

  As described above, according to the present invention, it is possible to perform a stepwise state by determining a combination of a received electric field level, a received communication quality (error level), and a transmission data amount with respect to antenna switching during individual channel communication in a mobile terminal. The antenna can be switched.

It is a block diagram which shows the structure of the mobile communication system which concerns on this invention. In the mobile communication system which concerns on this invention, it is a flowchart which shows antenna switching operation start. In the mobile communication system which concerns on this invention, it is a figure which shows communication quality degradation determination. It is a figure which shows the flow of the data in the transmission part of the mobile communication system which concerns on this invention. In the mobile communication system which concerns on this invention, it is a figure which shows the antenna switching criteria. In the mobile communication system which concerns on this invention, it is a figure which shows the antenna switching operation flow at the time of switching OK. In the mobile communication system which concerns on this invention, it is a figure which shows the antenna switching operation | movement flow at the time of switching NG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Application control part 2 Communication control part 21 Switching control part 22 Transmission part 23 Data amount determination part 24 Quality determination part 25 Reception part 3 Signal processing part 31 Transmission processing part 32 Reception processing part 33 Transmission / reception switch 4 Antenna switching part 51,52 antenna

Claims (2)

In a mobile terminal that includes a plurality of antennas and performs communication using a data transmission channel assigned for data communication,
A level determination unit that compares a received electric field level by the antenna with a threshold;
A synchronization determination unit for determining data for synchronization with data transmission by the data transmission channel;
A switching unit that determines switching of the plurality of antennas in synchronization with data transmission on the data transmission channel based on a determination result output from the level determination unit and the synchronization determination unit. ,
When the received electric field level by the antenna is equal to or higher than the threshold, the switching unit does not switch the antenna,
When the received electric field level by the antenna is less than or equal to the threshold, the synchronization determination unit determines the communication quality of the received data from the antenna in a stepwise manner, and then transmits the transmission data transmitted on the transmission channel The switching unit has a function for switching antennas based on the communication quality and the transmission data amount, and after switching the antennas, before and after switching the antennas. A portable terminal having a function of determining whether to maintain switching by comparing received electric field levels . In an antenna switching control method that includes a plurality of antennas and switches a plurality of antennas provided in a mobile terminal that performs communication using a data transmission channel assigned for data communication.
Comparing a reception electric field level and the threshold value by the antenna,
Determining data for synchronization with data transmission over the data transmission channel;
Based on said comparison result and said judgment result, wherein in synchronism with the data transmission in the data transmission over the channel and a determining switching of the plurality of antennas,
When the received electric field level by the antenna is equal to or higher than the threshold, the antenna is not switched by the switching unit
When the received electric field level by the antenna is less than or equal to the threshold value, the synchronization determination unit determines the communication quality of the received data from the antenna in stages, and then the transmission data transmitted on the transmission channel The amount of data is determined in stages, and the antenna is switched by the switching unit based on the communication quality and the amount of transmission data. After the antenna is switched, the received electric field level before and after the antenna switching is determined. An antenna switching control method characterized by determining whether to maintain switching in comparison .

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