JP4706524B2 - Wireless terminal - Google Patents

Description

  The present invention relates to a wireless terminal, and more particularly, to a wireless terminal that supports multiband and diversity reception.

  Every year, demands for high data rate support are increasing in wireless terminals, for example, mobile terminals. In order to cope with this, diversity reception is effective and has been studied. On the other hand, multiband support is also indispensable due to the tight frequency due to the increase in the number of users and the demand for international roaming. Under such circumstances, the enlargement of the radio circuit scale has become an issue.

  FIG. 5 is a configuration diagram of an example of a conventional portable terminal. Referring to the figure, a conventional portable terminal 200 includes antennas 201 and 202, an antenna switch 203, a duplexer A 204, a band pass filter (BPF) 205, a transmission circuit A 206, a first reception circuit 208, 2 receiving circuit 209, wireless IC (integrated circuit) 215, rake receiving unit 219, and CPU (central processing unit) 220.

  The antenna switch 203 includes four switches SW1 to SW4. The wireless IC 215 includes mixers 210 and 211, analog baseband units 212 and 213, a control circuit 214, and a register 221. The rake receiver 219 includes a 1-system demodulator 216, a 2-system demodulator 217, and a combiner 218.

  This portable terminal 200 supports single band diversity reception of only the operating frequency band A for explanation. One of the receiving circuit systems (bandpass filter 205, second receiving circuit 209, etc.) is added for diversity only in order to support a high data rate. That is, the band pass filter 205 is used instead of the duplexer. Further, the output of the analog baseband unit 213 is inevitably handled as reception data dedicated to the second system and is input to the second system demodulator 217, so the wireless IC 215 does not have the switch 114 shown in FIG.

  Further, the 1-system demodulator 216 and the 2-system demodulator 217 are optimally mounted in consideration of the diversity effect, circuit scale, current consumption, and the like, and thus do not necessarily have the same circuit configuration. In that case, software may be designed so that the second-system demodulator 217 operates at the time of diversity reception.

  FIG. 6 is a configuration diagram of another example of a conventional portable terminal. Referring to the figure, a conventional portable terminal 300 includes antennas 301 and 302, an antenna switch 303, a duplexer A304, a duplexer B322, a bandpass filter 305, a transmission circuit A306, a first reception circuit 308, A transmission circuit B307, a first reception circuit 324, a second reception circuit 309, a wireless IC 315, a rake reception unit 319, and a CPU 320 are included.

  The antenna switch 303 includes six switches SW1 to SW6. The wireless IC 315 includes mixers 310, 311, 325, analog baseband units 312, 313, a control circuit 322, and a register 321. The rake receiving unit 319 includes a first-system demodulator 316, a second-system demodulator 317, and a combiner 318.

  The portable terminal 300 shown in the figure shows a conventional example in which the operating frequency band B is further added to the configuration shown in FIG. In this example, radio components are added for the increased frequency band, and the baseband unit is shared with the mobile terminal 200 of FIG. This is because the baseband unit does not need to be aware of the RF frequency, and it is more effective to reduce the development cost if the baseband unit is shared including the baseband control method.

  On the other hand, a wireless terminal that includes a plurality of antennas, a plurality of reception units, and a register conversion unit, stores frequency information in the register conversion unit, and performs multiband reception by the antenna and the reception unit is disclosed (see Patent Document 1). .

  In addition, a diversity receiving apparatus that includes a plurality of antennas and a plurality of receiving systems, and that a diversity circuit outputs diversity operation control information from reception state detection information and switches between antennas and frequencies is disclosed (see Patent Document 2).

  A radio link terminal including a switch for switching between two I / Q data is disclosed (see Patent Document 3).

Japanese Patent Laying-Open No. 2004-274097 (paragraphs 0017 to 0021, FIG. 1) JP-A-10-303793 (paragraphs 0024 and 0027, FIG. 1) No. 09-507004 (page 8, line 9 to page 9, line 5, Fig. 2)

  The diversity receiver using the antenna combining method can be realized by expanding the baseband unit to prepare a plurality of systems, and assigning antennas and reception RF circuits having different directivities to the baseband units. However, when the multi-band configuration is adopted in order to cope with any combination of frequencies, it is necessary to increase the number of RF circuits by the number of bands basically increased, which causes an increase in cost and mounting area of the radio part. There is a problem.

  On the other hand, none of the above Patent Documents 1 to 3 disclose an antenna switching mechanism in a wireless terminal capable of multiband and diversity reception.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless terminal that supports multiband and diversity reception that can reduce the cost and mounting area of the wireless portion.

In order to solve the above problems, a wireless terminal according to the present invention is a wireless terminal capable of multiband and diversity reception, and a plurality of receiving antennas, a plurality of receiving apparatuses, and a connection between the receiving antennas and the receiving apparatuses. and cut exchange El first switching means, the receiving apparatus and the cut-exchange El second switching means a connection with the devices connected to a subsequent stage, the first and second depending on whether the multi-band operation or diversity operation 2 viewed contains a switching control unit switching means and for switching the receiver device,
The switching control means is further provided with a register in which operating band identification information, information on whether to perform diversity control, power control information on whether to turn on the receiving device, and selection information on the receiving antenna are recorded. Is a wireless terminal that controls the first and second switch means and the receiving device with reference to the register, and a plurality of transmitting devices used in pairs with each receiving device; A plurality of duplexers connected between a switch means and a pair of the receiving device and the transmitting device, wherein each transmitting device has a different transmission frequency and each receiving device has the same receiving frequency; And

  Here, the operation of the present invention will be described. The wireless terminal according to the present invention receives two systems of received I / Q data output from the wireless unit at the interface between the wireless unit and the baseband according to the register setting of the wireless IC and for diversity. The second baseband unit can be freely assigned. At this time, the antenna switching control is performed so that the receiving circuit outputting I / Q data to the first baseband unit is connected to the antenna having the higher reception level and the other receiving circuit is connected to the antenna having the lower reception level. I do.

  According to the present invention, by including the above configuration, it is possible to obtain a wireless terminal that supports multiband and diversity reception that can reduce the cost and mounting area of the wireless portion.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of an example of a wireless terminal according to the present invention. As an example, this wireless terminal is a portable terminal that supports multiband and diversity reception, and particularly includes a plurality of duplexers in which two types of upstream frequency bands correspond to one type of downstream frequency band. In addition, this wireless terminal is a terminal that performs CDMA (code division multiple access) communication as an example.

  FIG. 1 is a configuration diagram of an example of a portable terminal according to the present invention. Referring to the figure, mobile terminal 100 according to the present invention includes antennas 101 and 102, antenna switch 103, duplexer A104, duplexer B105, transmission circuit A106, first reception circuit 108, and transmission circuit B107. The second receiving circuit 109, the wireless IC 115, the rake receiving unit 119, and the CPU 120 are configured.

  The antenna switch 103 includes four switches SW1 to SW4. The wireless IC 115 includes mixers 110 and 111, analog baseband units 112 and 113, a switch 114, a control circuit 122, and a register 121. The rake receiving unit 119 includes a 1-system demodulator 116, a 2-system demodulator 117, and a combiner 118.

  Further, the switch 114 in the wireless IC 115 is configured to include four switches SW5 to SW8.

  In addition, the mobile terminal 100 is configured to support a dual band of a band A composed of a set of transmission frequency band T1 and reception frequency band R1 and a band B composed of a combination of transmission frequency band T2 and reception frequency band R1. The frequency bands T1 and T2 may be non-adjacent frequency bands, or originally may be a division of one frequency band.

  Furthermore, the mobile terminal 100 has two antennas, a main antenna (antenna 101) and a sub antenna (antenna 102). These antennas are connected to the duplexer A 104 and the duplexer B 105 via the antenna switch 103.

  The antenna switch 103 includes four switches SW1 to SW4 for path switching therein, and the antenna path between the band A side and the band B side can be switched freely under the control of the wireless IC 115. FIG. 2 shows an example of a truth table of the antenna switch 103.

  The duplexer A104 is connected to the transmission circuit A106 having the frequency T1 and the first reception circuit 108 having the frequency R1. The duplexer B105 is connected to the transmission circuit B107 having the frequency T2 and the first reception circuit 109 having the frequency R1.

  The transmission circuit A106 and the transmission circuit B107 are composed of a baseband signal generation unit, a D / A converter, a filter, a quadrature modulator, a variable gain amplifier, a power amplifier, and the like, but these are not directly related to the present invention. Detailed description is omitted.

  Although the first receiving circuit 108 and the second receiving circuit 109 are composed of a low noise amplifier and a band pass filter, these are also not directly related to the present invention, and thus detailed description thereof is omitted.

  The first receiving circuit 108 and the second receiving circuit 109 are connected to the first mixer 110 and the second mixer 111 of the wireless IC 115, respectively, where the RF frequency signal is down-converted to a baseband frequency.

  The analog baseband units 112 and 113 are composed of variable gain amplifiers, low-pass filters, A / D converters, and the like, and perform signal amplification, band limitation, and conversion from analog to digital. Each of the analog baseband units 112 and 113 outputs a digital baseband signal (I / Q) orthogonal to each other. The above-described variable gain amplifier, low-pass filter, A / D converter and the like are not directly related to the present invention, and thus detailed description thereof is omitted.

  The switch 114 switches from which IC port the two I / Q signals output from the analog baseband units 112 and 113 are output. FIG. 3 shows an example of the truth table of the switch 114.

  Further, the output I / Q signal from the wireless IC 115 is despread by the rake receiving unit 119 and subjected to multipath separation / synthesis.

  The rake receiving unit 119 includes a 1-system demodulator 116 and a 2-system demodulator 117 that perform despreading, channel setting, delay adjustment, and the like, and a combiner 118.

  Here, at the time of non-diversity reception, the second demodulator 117 is turned off. The I / Q signal input to the 1-system demodulator 116 is defined as I / Q data (1), and the I / Q signal input to the 2-system demodulator 117 is defined as I / Q data (2).

  The CPU 120 controls the entire mobile terminal 100. In particular, control of the wireless IC 115 is performed by setting predetermined data in the register 121.

  The register 121 stores operation band identification information, diversity ON / OFF control bits (diversity control), power control (power control), antenna selection, PLL (phase locked loop) frequency control information (not shown), and the like. The circuit 122 performs control of the antenna switch 103 and the switch 114 and power control of each block of the wireless IC 115 (not shown) based on the setting of the register 121. FIG. 4 shows an example of the setting of the register 121.

  Next, the operation of the mobile terminal 100 will be described with reference to FIGS.

  First, the truth table of the antenna switch 103 in FIG. 2 will be described. The item “operating state” in the left column indicates whether it is diversity, whether it is a main antenna or a sub antenna, and whether a band is A or B.

  The center column shows the corresponding “switch input”. That is, a binary signal input to a control terminal (not shown) of the switch 103 for selecting one of the switches SW1 to SW4 is shown, and the binary signal is output from the control circuit 122.

  The “switch state” in the right column indicates the ON (closed) or OFF (open) state of the switches SW1 to SW4 corresponding to “switch input”.

  Next, an example of the truth table of the switch 114 in FIG. 3 will be described. “Diversity” in the “operating state” in the left column indicates whether or not diversity, and “power source” indicates the power source of the wireless IC 115 (all power sources of the mixers 110 and 111 and the analog baseband units 112 and 113, that is, the 1-system and 2-system analogs). Whether the base band main power source is ON or OFF, and “band” indicates whether the band is A or B.

  Further, “first” of “reception circuit control” in the center column indicates whether the power of the first reception circuit 108 is ON or OFF, and “second” indicates whether the power of the second reception circuit 109 is ON or OFF.

  The “switch state” in the right column indicates whether the switches SW5 to 8 are ON (closed) or OFF (open).

  In the figure, when the “power supply” is off (OFF), the power supply of the wireless IC 115 (all the power supplies of the mixers 110 and 111 and the analog baseband units 112 and 113) is turned off. And the operation of the 2-system analog baseband unit is stopped.

  In addition, the control circuit 122 controls the power ON / OFF of the first receiving circuit 108 and the second receiving circuit 109. Further, the control circuit 122 separately controls the power ON and OFF of the mixer 110 and the analog baseband unit 112, and the mixer 111 and the analog baseband unit 113. However, this is based on the premise that the main power sources of the 1-system and 2-system analog baseband units are ON.

  Hereinafter, for the sake of simplicity, as an example, it is assumed that the reception level of the main antenna (antenna 101) is always higher than the reception level of the sub-antenna (antenna 102). That is, the antenna 101 side is the main branch.

(1) When non-diversity operation is performed in operation band A:
The CPU 120 stores in the register 121 the operation band identification information bit “0”, the diversity ON / OFF control bit “0”, the power control (power control) bit “1”, the antenna selection bit “0”, and the transmission frequency. ft1 and the reception frequency are set to fr1 (see FIG. 4).

  Therefore, the control circuit 122 turns “ON” (closed) SW5 and SW8 of the switch 114 (see the third stage in FIG. 3).

  Therefore, the data on the analog baseband unit 112 side is input to the 1-system demodulator 116 as I / Q data (1).

  Also, the control circuit 122 turns off (opens) the power of the second receiving circuit 109, the mixer 111, and the analog baseband unit 113 (see the third stage in FIG. 3).

  Further, the control circuit 122 sets SW1 of the antenna switch 103 to “ON” (closed) (see the first stage in FIG. 2), and the main antenna 101 and the duplexer A104 are connected.

  In addition, the CPU 120 turns off the second demodulator 117.

(2) When operating in diversity band A:
That is, the CPU 120 sets the diversity ON / OFF control bit of the register 121 to “1” during high-speed communication or when the reception electric field is low and sufficient communication quality cannot be ensured by the antenna switching type diversity (see FIG. 4). Therefore, the control circuit 122 turns on the power of the second receiving circuit 109, the mixer 111, and the analog baseband unit 113 as well as the power of the first receiving circuit 108, the mixer 110, and the analog baseband unit 112 (from the bottom of FIG. 3). At the same time, SW1 and SW4 of the antenna switch 103 are set to “ON” (closed) (see the fourth stage from the bottom in FIG. 2), the main antenna 101 and the duplexer A104 are connected, and the sub-antenna 102 And the duplexer B105 are connected to each other.

  Further, the CPU 120 turns on the second demodulator 117.

  Further, the control circuit 122 turns on SW5 and SW8 of the switch 114.

  Therefore, the data on the analog baseband unit 112 side is input to the 1-system demodulator 116 as I / Q data (1), and the data on the analog baseband unit 113 side is input to the 1-system demodulator 117 as I / Q data (2). Is input. The outputs of the two demodulators are combined at the maximum ratio by the combiner 118.

(3) Non-diversity operation in operation band B:
The CPU 120 stores the operation band identification information bit “1”, the diversity ON / OFF control bit “0”, the power control (power control) bit “1”, the antenna selection bit “0”, and the transmission frequency in the register 121. ft2 and the reception frequency are set to fr1 (see FIG. 4).

  Therefore, the control circuit 122 turns “ON” (closed) SW6 and SW7 of the switch 114 (see the fourth stage in FIG. 3).

  Therefore, the data on the analog baseband unit 113 side is input to the 1-system demodulator 116 as I / Q data (1).

  In addition, the control circuit 122 turns off (opens) the power of the first receiving circuit 108, the mixer 110, and the analog baseband unit 112 (see the fourth stage in FIG. 3).

  Further, the control circuit 122 sets SW2 of the antenna switch 103 to “ON” (closed) (see the second stage in FIG. 2), and the main antenna 101 and the duplexer B105 are connected.

  In addition, the CPU 120 turns off the second demodulator 117.

(4) When diversity operation is in operation band B:
The CPU 120 sets the diversity ON / OFF control bit of the register 121 to “1” (see FIG. 4). Therefore, the control circuit 122 turns on the power of the second receiving circuit 109, the mixer 111, and the analog baseband unit 113 as well as the power of the first receiving circuit 108, the mixer 110, and the analog baseband unit 112 (the lowest stage in FIG. 3). At the same time, SW2 and SW3 of the antenna switch 103 are set to “ON” (closed) (see the third stage from the bottom in FIG. 2), the main antenna 101 and the duplexer B105 are connected, and the sub-antenna 102 and the duplexer A104 are connected. And become connected.

  Further, the CPU 120 turns on the second demodulator 117.

  Further, the control circuit 122 turns “ON” SW6 and SW7 of the switch 114 (see the lowermost stage in FIG. 3).

  Therefore, the data on the analog baseband unit 113 side is input to the 1-system demodulator 116 as I / Q data (1), and the data on the analog baseband unit 112 side is input to the 1-system demodulator 117 as I / Q data (2). Is input. The outputs of the two demodulators are combined at the maximum ratio by the combiner 118.

  As described above, according to the present invention, since the rake receiving unit 119 can operate without being aware of the operating frequency band, the baseband hardware can be used for any combination of frequency bands. Further, since it is not necessary to design a new software, the development cost can be reduced.

  Further, according to the present invention, since the restriction on the connection between the radio unit and the baseband unit is reduced, the degree of freedom in designing the RF front end unit is increased, so that the number of RF parts can be reduced.

It is a block diagram of an example of the radio | wireless terminal which concerns on this invention. It is a figure which shows an example of the truth table of the antenna switch 103. It is a figure which shows an example of the truth table of the switch 114. 6 is a diagram illustrating an example of setting of a register 121. FIG. It is a block diagram of an example of the conventional portable terminal. It is a block diagram of another example of the conventional portable terminal.

Explanation of symbols

1-8 switch (SW)
100 Mobile terminal 101, 102 Antenna
103 Antenna switch
104 Duplexer A
105 Duplexer B
106 Transmission circuit A
107 Transmission circuit B
108 First receiving circuit
109 Second receiving circuit 110, 111 Mixer 112, 113 Analog baseband unit
114 switch
115 wireless IC
116 System 1 demodulator
117 2 system demodulator
119 Lake receiver
120 CPU
121 registers
122 Control circuit

Claims (3)

A wireless terminal capable of multiband and diversity reception,
A plurality of receiving antennas, a plurality of receiving devices, and the receiving antenna and off exchange El first switch means connected with said receiving apparatus, obtain replacement disconnect the device connected the receiving device and their subsequent a second switching means, depending on whether the multi-band operation or diversity operation switches the first and second switch means and said receiving device and a switching control unit seen including,
Furthermore, there is provided a register in which operation band identification information, information on whether to perform diversity control, power control information on whether to turn on the receiving apparatus, and selection information on the receiving antenna are recorded,
The switching control means is a wireless terminal characterized by controlling the first and second switch means and the receiving device with reference to the register,
A plurality of transmitting devices used in pairs with each receiving device, and a plurality of duplexers connected between the first switch means and the pair of receiving device and transmitting device,
A wireless terminal characterized in that the transmission frequency of each transmission device is different and the reception frequency of each reception device is the same . 2. The wireless terminal according to claim 1, wherein the wireless terminal is a terminal that performs code division multiple access (CDMA) communication, and a device connected to a subsequent stage of the receiving device is a demodulator of a rake receiving unit. The wireless terminal according to claim 2, wherein a CPU (central processing unit) that sets the information is included in the register, and the CPU performs on / off control of a demodulator of the rake receiving unit.

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