JP3815483B2 - Wireless terminal device - Google Patents

Description

  The present invention relates to a wireless terminal device, and more particularly, to a wireless terminal device that enables diversity reception using a plurality of (two) transmission / reception antennas without interruption of a call.

FIG. 4 shows an appearance of a conventional wireless terminal device.
A wireless terminal device 100 shown in FIG. 4 is a foldable mobile phone, and a case is constituted by an upper body 101 having a liquid crystal display 103 and a lower body 102 having a built-in antenna 104 built therein. The upper main body 10l and the lower main body 102 are rotatably coupled by a hinge portion 105, and are about half the size when folded.

  For example, when browsing the Internet using the wireless terminal device 100 of FIG. 4, if the user operates with the lower body 102 held by hand, the periphery of the built-in antenna 104 is covered with the hand. In this state, the reception level may be greatly deteriorated.

  Therefore, there is a model that employs an antenna diversity system in which two antennas are mounted on a single wireless terminal device, and radio waves received by the two antennas are switched to reduce changes in the reception level of the radio waves.

  FIG. 5 shows an appearance of a wireless terminal device 200 having two antennas. In FIG. 5, the same reference numerals are used for the same parts as in FIG. As shown in FIG. 5, the wireless terminal device 200 includes a built-in antenna 104 in the lower main body 102 and a whip antenna 106 (or a helical antenna) in one of the corner portions of the upper main body 101. . The whip antenna 106 usually employs an expansion / contraction structure that is mostly housed in the housing.

  In addition to the case where the antenna part is covered with the hand as described above by the antenna diversity method using the reception output of the built-in antenna 104 and the whip antenna 106, multipath fading and interference wave generated depending on the use situation Can be less affected by

FIG. 6 shows a configuration of a general antenna diversity receiving unit in a time division multiple access (TDMA) wireless terminal apparatus.
Antennas 202 and 203 and a receiving unit 204 are connected to the antenna changeover switch 201. Further, a reception level measuring unit 205 for measuring the reception level is connected to the receiving unit 204, and a control unit 206 is connected to the reception level measuring unit 205 and the antenna changeover switch 201.

In FIG. 6, the wireless terminal device 200 measures the reception level with the reception level measuring unit 205 while receiving data with any one of the antennas 202 and 203 in the slot divided to be occupied by the own station.
In addition, the reception level is measured by the reception level measuring unit 205 by switching to the other antenna in the remaining slots not occupied by the own station. The control unit 206 controls the antenna changeover switch 201 so that the reception level of the two antennas is compared, and the reception antenna with the higher reception level is selected in the own station occupied slot to be received next. Thereby, antenna diversity is achieved.

The configuration in FIG. 6 corresponds to a TDMA wireless terminal device, but the case where this configuration is applied to a CDMA (Code Division Multiple Access) wireless terminal device will be described.
In the case of the CDMA system, the reception level is always measured while receiving data during communication. Therefore, to compare the reception levels of two antennas, if the reception level of the antenna is low when temporarily switching to the other antenna when receiving with one antenna, Even if the antenna is returned to the antenna before switching immediately after measuring the reception level, data cannot be received during the switching time, and communication may be temporarily interrupted. Therefore, in the CDMA system, a configuration in which a reception unit and a reception level measurement unit are provided for each of the two antennas is unavoidable. This configuration will be described with reference to FIG.

FIG. 7 shows the configuration of a CDMA wireless terminal device.
The wireless terminal device 300 is connected to the receiving unit 301 connected to the antenna 302, the receiving unit 303 connected to the antenna 304, the reception level measuring unit 305 connected to the receiving unit 301, and the receiving unit 303. The reception level measurement unit 306, a control unit 307 that controls the reception level measurement units 305 and 306, and a reception system changeover switch 308 that switches the reception output of the reception level measurement unit 305 or 306 are configured.

  In the case of a CDMA wireless terminal device, the occupied slot cannot be divided on the time axis, so the configuration of FIG. 6 cannot be used. However, two antennas 302 and 304, two receivers 301 and 303, two reception level measuring units 305 and 306, and one reception system changeover switch 308 are provided, so that two antennas are always provided. The reception level can be measured while receiving with the antennas 302 and 304, and data can be received with the antenna with the higher reception level, so that antenna diversity reception is possible even with the CDMA system.

In addition, as a configuration example of diversity transmission / reception in a CDMA base station, for example, each of received signals of two antennas is individually despread, combined, and error-corrected (by an error correction decoding circuit). In addition to obtaining the received data of the channel, the antenna selection signal is obtained by the error correction decoding circuit, and this antenna selection signal and the output of the spreading circuit are used for switching the antenna switch, thereby reducing interference due to cross-correlation between channels. Therefore, it is possible to improve communication quality and increase subscriber capacity (see, for example, Patent Document 1).
JP-A-9-69808

  However, according to the conventional wireless terminal device, in the configuration of FIG. 7, it is necessary to provide two reception units and two reception level measurement units, one antenna, one reception unit, and one power measurement unit. 6 is significantly disadvantageous in terms of circuit scale and current consumption.

  In addition, depending on the application such as telephone call, videophone, web browsing, etc., the most frequently used antenna and the reception level can be increased for each application using a probabilistic method such as market research in the usage scene. There is also a method to be used by assembling, but in this case, there are individual differences among users, and the two antennas cannot be reliably controlled optimally with respect to the reception level.

  Furthermore, according to the configuration of Patent Document 1, unlike the configuration in which reception diversity is performed by switching antennas, the configuration uses two antennas for transmission and reception at the time of diversity. As described in FIG. 7, the present invention is not applicable to the configuration using either one of the two antennas having the higher reception level. Further, since the configuration is complicated, it is unsuitable for application to a portable wireless terminal device.

    An object of the present invention is to provide various communication systems such as W-CDMA with a simple configuration including a plurality of (for example, two) antennas, one receiving unit, and one receiving level measuring unit. An object of the present invention is to provide a wireless terminal device capable of transmitting and receiving antenna diversity without interruption of communication.

To achieve the above object, the present invention provides a plurality of antennas, reception means for receiving radio from one base station via one of the antennas, reception level measurement means for measuring the reception level, a reception level measuring means for measuring the reception level of the antenna including the current transmission and / or reception to that antenna, consists of a control means for comparing the reception levels of the plurality of antennas, wherein, individual control An interruption period for temporarily interrupting transmission / reception of a channel is generated, and the interruption period is generated by communication using a CDMA system, and the reception level measurement means performs the transmission and / or reception within the interruption period. Measuring at least one reception level of another antenna other than the antenna being installed , wherein the control means measures another antenna measured by the reception level measuring means. The level of the comparing the transmission and / or reception to and antenna level in the interruption period, when the reception level is less than the other antenna, from the transmitting and / or receiving and has an antenna And switching to the antenna. Alternatively, a plurality of antennas, a reception level measurement unit that measures a reception level when radio waves from a base station are received by one of the plurality of antennas, and measurement of the reception level by the reception level measurement unit When the value falls below a predetermined threshold value or at regular intervals, the reception level of the antenna used immediately before is compared with the reception level of the other antenna, and the reception level of the other antenna is compared. A wireless terminal device is provided, comprising: a control unit that performs switching to the other antenna during a period from the start to the end of a period in which transmission / reception is temporarily interrupted when the antenna is higher.

According to the configuration of the present invention as described above, the reception level measurement unit measures the reception level of the radio wave from the base station, and is in use when the measured value is less than the threshold value or at a timing for each fixed period. The two reception levels measured by the reception level measurement unit for each of the antenna and other antennas are compared by the control unit, and switching to the antenna with the higher reception level is temporarily performed without interruption of data communication. Execute within the period when transmission / reception is interrupted.
As a result, it is possible to perform transmission / reception antenna diversity without affecting communication in a wireless terminal device adopting the CDMA scheme.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a wireless terminal apparatus according to an embodiment of the present invention.
The wireless terminal device 1 includes antennas 11 and 12, an antenna changeover switch 13, an antenna duplexer 14, a transmission unit 15, a reception unit 16, a despreading unit 17, and PN (pseudorandom noise) generators 18 and 25. A decoder 19, a broadcast channel reception level measuring unit 20, a control unit 21, a coder 23, and a spreading unit 24. The transmitter 15 and the receiver 16 form a radio unit.

  The wireless terminal device 1 can communicate wirelessly with the base station 30 including the antenna 31 via the antennas 11 and 12. The base station 30 transmits a broadcast channel (Broadcast Channel: BCH or broadcast information) 32, and the broadcast channel 32 is received by the wireless terminal device 1. The broadcast channel 32 includes system information, cell information, and the like. The spreading unit 24 performs spectrum spreading using a spreading code (PN code), and the despreading unit 17 performs despread spectrum spreading using a spreading code. The decoder 19 decodes the output signal of the despreading unit 17 and generates reception data 28. The coder 23 encodes the transmission data 22.

  The PN generators 18 and 25 generate a spreading code (PN code) under the control of the control unit 21 and supply it to the despreading unit 17 and the spreading unit 24. For example, the transmission unit 15 generates radio waves in the 800 MHz band, 1500 MHz band, and the like, and the reception unit 16 includes a circuit for receiving radio waves from the base station 30. The antenna duplexer 14 allows one of the antennas 11 and 12 to be shared for transmission and reception, and the antenna selector switch 13 selects one of the antennas 11 or 12 by the control unit 21.

  An antenna changeover switch 13 is connected to the antennas 11 and 12, and an antenna duplexer 14 is connected to the antenna changeover switch 13. A transmitter 15 and a receiver 16 are connected to the antenna duplexer 14, and a despreading unit 17 is connected to the receiver 16. Connected to the despreading unit 17 are a PN generator 18, a decoder 19 for decoding the output of despreading, and a broadcast channel reception level measuring unit 20. A control unit 21 is connected to the PN generator 18, the decoder 19, the broadcast channel reception level measurement unit 20, and the antenna changeover switch 13. A coder 23 that encodes transmission data 22 is connected to the control unit 21, a spreading unit 24 is connected to the coder 23, and a transmitting unit 15 is connected to the spreading unit 24. A PN generator 25 is provided between the diffusion unit 24 and the control unit 21.

  For example, when the wireless terminal device 1 is a W-CDMA (wide band-Code Division Multiple Access) mobile phone, the 3GPP (Third Generation Partnership Project: a project for creating a standard established in 1998) is the basic specification. It is said. In this embodiment, 3GPP compressed mode (compressed mode, a function that enables measurement of different frequency cells to perform different frequency handover), etc., is temporarily sent and received without blocking data communication. By generating a means for interrupting the transmission (for example, transmission gap (transmission gap)) and using the generated means, it is possible to switch to a standby antenna using the period during which transmission / reception is interrupted. The reception level is measured, the measured value is compared with the reception level value of the antenna used for communication, and these antennas having a high reception level are used after the end of the transmission / reception interruption period. Thus, with a relatively simple configuration, transmission / reception antenna diversity can be achieved in the CDMA system without interruption of the call. There are several methods for realizing the compressed mode, but in the above description of the present embodiment, a method of changing the diffusion rate is used.

FIG. 2 is a diagram illustrating processing between the wireless terminal device and the base station illustrated in FIG.
In the figure, S represents a step.
The wireless terminal device 1 is in communication with the base station 30 through the antenna 11 (SlOl, 201), and the broadcast channel 32 is transmitted from the base station 30 with constant power (S202). During communication, in the wireless terminal device 1, when the broadcast channel 32 is received, the reception level is measured by the broadcast channel reception level measuring unit 20, and stored as a measured value A in a register attached to the control unit 21 (SlO2 ). The control unit 21 compares the preset threshold value with the measured value A (SlO3). As a result of the comparison, when the measured value A is lower than the threshold value (Y), the process of SlO4 is executed, and in the opposite case (N), the process of SlOl is continued.

  When [threshold value> measured value A] is determined in SlO3, the control unit 21 determines the timing when the wireless terminal device 1 enters the compressed mode (SlO4), and sends this information to the coder 23 for coding. Then, the data is transmitted to the base station 30 via the spreading unit 24, the transmission unit 15, and the antenna 11 (SlO5). Receiving the information from the wireless terminal device 1, the base station 30 adds the timing information to the transmission data 22 and transmits it to notify the terminal of the timing for starting the compressed mode (S203).

  In the wireless terminal device 1, the reception data from the base station 30 is processed by the reception unit 16 and the despreading unit 17, and further the timing information is decoded from the reception data by the decoder 19 (SlO6). The control unit 21 grasps the timing for starting the compressed mode. The control unit 21 increases the transmission data rate at the timing notified from the base station 30, issues an instruction to the PN generators 18 and 25 so that the chip rate does not change, and controls to decrease the spreading factor. (SlO7). At the same time, the base station 30 also increases the data rate and makes the spreading factor of the transmission / reception wave the same as that of the wireless terminal device 1 (S204). As a result, transmission / reception of data can be completed as soon as the data rate increases, and a transmission gap (a gap between n frames and n frames is formed without interruption of data without multiplication) Slot, and no data is transmitted / received in this slot).

  In the wireless terminal device 1, an instruction is issued from the control unit 21 to the PN generators 18 and 25, and the lowered spreading factor is restored (SlO8). Further, during the transmission gap, the control unit 21 issues an instruction to the antenna changeover switch 13 to switch from the antenna 11 to the antenna 12 (SlO9), and receives the broadcast channel 32 from the base station 30 (SllO). Then, the reception level of the broadcast channel 32 when the antenna 12 is used is measured by the broadcast channel reception level measuring unit 20, and the measured value B is stored in the register (Slll). The measured value B is compared with the measured value A stored in the register by SlO2 (Sl12).

  In the comparison of Sl12, when [measured value A> measured value B] is determined (Y), after the transmission gap ends, the control unit 21 controls the antenna changeover switch 13 to switch from the antenna 12 to the antenna 11. Do (Sl13). Further, when [measured value B> measured value A] is determined in Sl12 (N), the control unit 21 does not issue an instruction to the antenna changeover switch 13, and communicates with the base station 30 while the antenna 12 is connected. Resume (Sl14). Thereafter, it is determined whether or not there is a call interruption (such as call termination) (Sl12). If it is not completed, the process is returned to SlOl.

  FIG. 3 shows an appearance of the wireless terminal device 1 according to the present embodiment. In FIG. 3, the same reference numerals are used for the same parts as in FIG. The wireless terminal device 1 is a foldable type, and the housing includes an upper main body 101 having a liquid crystal display 103, a lower main body 102 provided with numeric keys and function switches (not shown) on an operation surface, and an upper main body 101. And a hinge portion 105 for opening and closing the lower main body 102 to near 0 to 180 °. A built-in antenna 11 is installed in the lower body 102, and a whip-shaped antenna 12 is provided at one of the corners of the upper body 101.

  In FIG. 3, the wireless terminal device 1 is in use, the antenna 11 (built-in antenna 104) is selected at the start of communication, and the user is using the lower body 102 while holding it with one hand. To do. In this state of use, the built-in antenna 11 is covered with hands, so that the reception level is lowered and the reception level of the broadcast channel 32 is also lowered. On the other hand, when the antenna 12 is selected, the reception level of the broadcast channel 32 does not decrease because the periphery of the upper body 101 is a space. Although there is a difference in sensitivity depending on the type and shape of the antenna, the reception level of an antenna covered with a hand is lower than that of an antenna not covered with a hand. Therefore, when the antenna 11 is covered with a hand, it can be considered that the reception level of the antenna 12 becomes higher. Therefore, as described in SlO 9 in FIG. 2, the control unit 21 and the antenna changeover switch 13 operate, and the antenna 11 is switched to the antenna 12. Such antenna switching enables a call with good communication quality.

  On the other hand, during communication with the antenna 12 selected, for example, when the hand is switched from the lower main body 102 to the upper main body 101, the antenna 12 approaches the steel frame of the building while talking while walking. In some situations, such as when the antenna 12 is sandwiched between people, the reception level of the antenna 12 may be lower than that of the antenna 11. In such a case, the reception levels of the broadcast channels 32 of the antenna 11 and the antenna 12 are compared with the measured values A and B as described in SllO to Sl14 in FIG. If it is higher, switching from the antenna 12 to the antenna 11 makes it possible to obtain better call quality.

  In addition, in the said embodiment, although it was set as the structure provided with two antennas, the structure provided with a 3 or more several antenna may be sufficient as invention of the portable terminal device of this invention. The wireless terminal device 1 of the present invention has been described by taking a mobile phone as an example. However, the present invention is not limited to a mobile phone, but may be a PHS (Personal Handy-phone System) phone, a PDA (Personal Digital Assistant), or the like. In addition, the present invention can be applied to various portable electronic devices having a communication function with a public wireless communication network. In addition, although the mobile phone has been shown as a folding type, it can be applied to any mobile communication device as a matter of course.

  In the above embodiment, the reception gap of the specific channel is measured by switching the antenna using the transmission gap in the compressed mode. However, the present invention is limited to the transmission gap in the compressed mode. It is not a thing, It is a portable terminal device which communicates by methods other than a time division multiplexing system, Comprising: What is necessary is just a portable terminal device using the period which transmission / reception is interrupted temporarily in the portable terminal device of such a system. When there are a plurality of unused antennas, the signal level of one of the waiting antennas may be measured during the compressed mode or the equivalent mode, and two or more antennas may be used. The signal level of the antenna may be measured. In addition, the period is generated at least once before the antenna is switched, but when this period is generated a plurality of times, the number of times measured during each period is one time or a plurality of times. Also good.

  Further, in the above embodiment, the threshold value and the measured value are compared with SlO3 in FIG. 2, and when [threshold value> measured value], the comparison is made between the reception level of the current antenna and the other antennas ( However, instead of comparing [threshold value> measured value], reception level comparison (Sl12) between the current antenna and other antennas may be performed at regular intervals. The instruction to start the operation of comparing the reception levels of the antennas can be performed by the terminal itself (for example, the control unit 21). In the present invention, the start instruction is also given from the base station to the portable terminal device. You can also.

  Further, the broadcast channel reception level measurement unit 20 measures the reception level of a specific channel (specifically, the broadcast channel), but the present invention is not limited to the specific channel. For example, RSSI (Received It may be configured to measure the reception level of information such as Signal Strength Indicator (BER), BER (Bit Error Rate), BLER (Block Error Rate), or RSCP (Received Signal Code Power), Ec A physical channel such as / N can also be used as information. In the present invention, as the threshold value, the reception level measurement unit 20 can select one of these information or use a combination of two or more as appropriate. When two or more pieces of information are selected, the present invention weights each piece of information based on the importance of a communication system or communication method as the threshold, and sets each value of the selected piece of information. And the sum of products multiplied by the weights determined based on the importance of the respective information can be set as the threshold value.

For example, if the selected information is RSSI and BER, and these weights are W _R and W _B , respectively, the reception levels RL ₁₁ and RL ₁₂ of the antenna 12 compared with the current antenna 11 are: Following formula
RL ₁₁ = RSSI ₁₁ • W _R + BER ₁₁ • W _B (F1)
and
RL ₁₂ = RSSI ₁₂ · W _R + BER ₁₂ · W _B (F2)
Where RSSI ₁₁ and BER ₁₁ and RSSI ₁₂ and BER ₁₂ are the RSSI and BER values of antennas 11 and 12, respectively.
Here, if RL ₁₁ <RL ₁₂ , the control unit 21 instructs the switch 13 to switch between the active antenna 11 and the standby antenna 12, and the switch 13 switches.

  Furthermore, the period in which transmission / reception is temporarily interrupted is the compressed mode in the 3GPP specification of the W-CDMA system, but the present invention is not limited to the W-CDMA system, and the period of communication is A wireless terminal device of a communication system that must transmit and receive without being cut off, for example, one of CDMA and W-CDMA, DS (Direct Spread) -CDMA, MC (Multi Carrier) -CDMA (or , CDMA2000) system, PHS system, and other wireless terminal devices, and the same effects as in the case of the W-CDMA system described above can be obtained.

  The wireless terminal device of the present invention measures the reception level of the radio wave from the base station by the reception level measuring unit, and when the measured value becomes less than the threshold value or at a timing for every fixed period, The two reception levels measured by the reception level measurement unit are compared by the control unit, and switching to the antenna with the higher reception level is temporarily interrupted without interrupting data communication. Since it was done within the period, it can be used for wireless terminal equipment adopting communication methods such as W-CDMA, CDMA, DS-CDMA, MC-CDMA, PHS, etc. that must be transmitted and received without interruption Thus, a device having such a communication function can perform transmit / receive antenna diversity without affecting the communication.

It is a block diagram which shows the structure of the radio | wireless terminal apparatus which concerns on embodiment of this invention. 3 is a flowchart showing processing between the wireless terminal device shown in FIG. 1 and a base station. It is a typical perspective view which shows the external appearance of the radio | wireless terminal apparatus which concerns on this Embodiment. It is a typical perspective view which shows the external appearance of the conventional radio | wireless terminal apparatus. It is a typical perspective view which shows the external appearance of the radio | wireless terminal apparatus provided with two antennas. It is a block diagram which shows the structure of the general antenna diversity receiving part of the radio | wireless terminal apparatus of a time division multiplexing (TDMA) system. 1 is a block diagram illustrating a configuration of a code division multiplexing (CDMA) wireless terminal apparatus. FIG.

Explanation of symbols

1 Wireless terminal device
11, 12, ... 31 Antenna
13 Antenna selector switch
14 Antenna duplexer
15 Transmitter
16 Receiver
17 Despreading section
18 PN generator
19 Decoder
20 Broadcast channel reception level measurement section
21 Control unit
22 Transmission data
23 Coda
24 Diffusion part
25 PN generator
26, 27 Timing information
28 Received data
30 base station
32 Information channel
100, 200, 300 Wireless terminal equipment
101 Upper body
102 Lower body
103 (Liquid crystal) display
104 Built-in antenna
105 Hinge
201 Antenna switch
202, 203, 302, 304 Antenna
204, 301, 303 Receiver
205, 305, 306 Reception level measurement section
206, 307 Control box
308 Reception system selector switch

Claims (9)

Multiple antennas,
Receiving means for receiving radio from one base station via one of the antennas;
A reception level measuring means for measuring the reception level;
A reception level measuring means for measuring the reception level of the antenna including the antenna currently transmitting and / or receiving;
Comprising a control means for comparing the reception levels of the plurality of antennas,
The control means generates an interruption period for temporarily interrupting transmission / reception of the individual control channel,
The interruption period is generated by communication using a CDMA system,
The reception level measuring means measures at least one reception level of an antenna other than the antenna that is transmitting and / or receiving within the interruption period;
The control means compares the level of the other antenna measured by the reception level measuring means with the level of the antenna that is transmitted and / or received within the interruption period, and receives the reception level of the other antenna. A wireless terminal apparatus that switches from the transmitting and / or receiving antenna to the antenna when:   The radio terminal apparatus according to claim 1, wherein the reception level measuring means receives a specific channel as a radio wave from the base station. The radio terminal apparatus according to claim 2 , wherein the specific channel is a broadcast channel. The reception level measuring means receives at least one information selected from the base station from RSCP (Received Signal Code Power), BER (Bit Error Rate), BLER (Block Error Rate) and Ec / N. The wireless terminal device according to claim 1, wherein the wireless terminal device is measured as follows.   5. The plurality of antennas according to claim 1, wherein the plurality of antennas include a built-in antenna disposed in a housing and a linear antenna in which a part of an element extends from the housing. Wireless terminal device.   6. The communication system according to claim 1, wherein the CDMA system is a communication system that must transmit and receive without interruption during communication including W-CDMA, CDMA, DS-CDMA, MC-CDMA, and PHS. The wireless terminal device according to item 1.   The wireless terminal according to any one of claims 1 to 6, wherein the interruption period is generated when a compressed mode in a 3GPP (Third Generation Partnership Project) specification of W-CDMA system is used. apparatus. Further, the wireless terminal device has a spreading means and a despreading means,
When shifting to the compressed mode, the control means changes the spreading factor of the spreading means and the despreading means so as to increase the transmission data rate, thereby forming a transmission gap in which data transmission / reception is not performed, 8. The wireless terminal apparatus according to claim 7, wherein control is performed so that the spreading factor is restored after the gap generation period ends.   The radio terminal apparatus according to any one of claims 1 to 8, wherein the generation of the interruption period is performed by a command or a directory by the base station or the radio apparatus itself.

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