JP2007124519A - Wireless communication device and wireless entrance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication device and wireless entrance system in which an active apparatus and a standby apparatus can be operated stably. <P>SOLUTION: In a first PLL unit 164a of an active apparatus 102a for transmission, a PLL circuit 162a and a PLL circuit 8a are cascaded and in a second PLL unit 164b of a standby apparatus 102b for transmission; whereas, a PLL circuit 162b and a PLL circuit 8b are cascade-connected. When a first or second reference oscillation signal is outputted from a first or second reference oscillator 14a or 14b via first and second switches 16a and 16b to the first and second PLL units 164a and 164b, the first and second PLL units 164a and 164b output first and second local signals frequency-locked with the inputted first or the second reference oscillation signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication device including an active device having a first reference oscillator and a first PLL unit, a standby device having a second reference oscillator and a second PLL unit, and a wireless entrance system including the wireless communication device.

  Conventionally, in a wireless entrance system in which wireless communication devices are arranged on a transmission side and a reception side, the transmission side wireless communication device has a redundant configuration including two devices, an active device and a standby device. A highly reliable system is realized in which a line is not disconnected when switching from the active system device to the standby system device required for maintenance of the wireless communication device.

  In this case, the reception-side wireless communication device has a redundant configuration in which an active device and a standby device are arranged in the same manner as the transmission-side wireless communication device. Therefore, the switching is performed on either the transmission side or the reception side. However, in this specification, switching on the transmission side will be described.

  FIG. 7 is a block diagram of the transmission-side wireless communication device 2 according to Patent Document 1.

  The transmission side wireless communication circuit 2 includes a standby system device 4b having a reference oscillator 6b and an active system device 4a having a PLL circuit 8a. The reference oscillator 6b transmits a second local signal to a frequency (not shown) of the standby system device 4b. Output to the converter. Further, the PLL circuit 8a outputs the first local signal, which is frequency-synchronized with the second local signal, to a frequency conversion unit (not shown) of the active device 4a.

  FIG. 8 is a block diagram of another transmitting-side radio communication device 9 according to Patent Document 2.

  Compared with the transmission side wireless communication circuit 2 (see FIG. 7), the transmission side wireless communication circuit 9 shares the reference oscillator 12 between the active system device 4a and the standby system device 4b via the hybrid unit (HYB) 10. The standby system device 4b is different in that a PLL circuit 8b is arranged. In this case, the reference oscillator 12 outputs a reference oscillation signal to each of the PLL circuits 8a and 8b via the hybrid unit 10, and the PLL circuit 8a has a first frequency synchronization with the input reference oscillation signal. The local signal is output to the frequency converter of the active device 4a, and the PLL circuit 8b outputs the second local signal synchronized with the input reference oscillation signal to the frequency converter of the standby device 4b. To do.

Japanese Patent Laid-Open No. 2003-32320 JP-A-9-252278

  However, the transmitting-side wireless communication device 2 (see FIG. 7) according to Patent Document 1 has the following problems.

  (1) Since the first and second local signals are frequency-synchronized, the active device 4a to which the second local signal is input when the standby device 4b is in an abnormal state such as a failure. There is a risk of an abnormal condition.

  (2) When the frequency of the first and second local signals is increased, the hardware configuration between devices that input and output the first or second local signal is restricted.

  Further, the transmitting-side wireless communication device 9 (see FIG. 8) according to Patent Document 2 has the following problems.

  (3) Since the active system device 4a and the standby system device 4b share the reference oscillator 12, when the reference oscillator 12 is in an abnormal state, the active system device 4a and the standby system device 4b are also in an abnormal state, As a result, the reliability of the transmission side wireless communication device 9 adopting the redundant configuration is lowered.

  FIG. 9 is a block diagram of the transmission side wireless communication device 15 devised by the present applicant on the assumption of the transmission side wireless communication devices 2 and 9 described above.

  In the transmission side wireless communication device 15, the first reference oscillator 14a and the first switch 16a are respectively arranged in the active device 4a, while the second reference oscillator 14b and the second switch 16b are respectively arranged in the standby device 4b. Has been. Here, the first switch 16a supplies the first or second reference oscillation signal output from the first or second reference oscillator 14a, 14b to the PLL circuit 8a based on a switching signal from a monitoring control unit (not shown). On the other hand, the second switch 16b supplies the first or second reference oscillation signal output from the first or second reference oscillator 14a, 14b to the PLL circuit 8b based on the switching signal.

  However, in this transmission-side radio communication device 15, the impact caused by the frequency error or phase deviation of the first and second reference oscillation signals generated during the switching operation of the first and second switches 16a and 16b is caused by the PLL circuits 8a and 8b. As a result, the loop response characteristics of the PLL circuits 8a and 8b cannot be ensured. In the PLL circuits 8a and 8b that generate the first and second local signals, a loop design is performed so that the C / N of the first and second local signals is optimized. A loop design that suppresses an impact generated when the two reference oscillators 14a and 14b are switched is not taken into consideration.

  The present invention has been made to solve the above-described problems, and provides a wireless communication device that enables stable operation of an active device and a standby device and a wireless entrance system including the wireless communication device. Objective.

  A wireless communication device according to the present invention includes a first reference oscillator that outputs a first reference oscillation signal, a working device having a first PLL unit in which a plurality of PLL circuits are cascade-connected, and a second reference oscillation signal that is output. A standby system device having a second PLL unit in which a plurality of PLL circuits and a plurality of PLL circuits are cascade-connected, and the first PLL unit includes the input first or second reference oscillation signal and its own PLL circuit Based on the first PLL oscillation signal generated in step (1), the first local signal that is frequency-synchronized with the first or second reference oscillation signal is generated, and the second PLL unit receives the first or second input PLL signal. Generating a second local signal that is frequency-synchronized with the first or second reference oscillation signal based on the second reference oscillation signal and the second PLL oscillation signal generated in each of the PLL circuits; Features and That.

  According to this configuration, the reference oscillation signal supplied to the first and second PLL units is changed from the first reference oscillation signal to the second reference oscillation signal or from the second reference oscillation signal to the first reference oscillation signal. Even if frequency fluctuations of the first and second reference generation signals occur when switching to a signal, the first and second PLL units can shock the frequency fluctuations by connecting the PLL circuits in cascade. Can be absorbed. In addition, in the frequency bands of the first and second reference oscillation signals and the first and second PLL oscillation signals, each PLL circuit can be configured with a device having a high C / N and a low cost. N and a PLL circuit that minimizes the impact can be realized.

  Therefore, the wireless communication device according to the present invention is compared with the transmission-side wireless communication device according to the prior art and the transmission-side wireless communication device devised by the present applicant on the premise of the transmission-side wireless communication device. The active system device and the standby system device can be stably operated when the first and second reference oscillators are switched.

  The first and second local signals include a carrier signal that modulates a transmission signal and a high-frequency signal that converts the frequency of the modulated transmission signal.

  Here, in the first and second PLL units, the loop bandwidth of the upstream PLL circuit connected to the first or second reference oscillator is equal to that of the downstream PLL circuit that outputs the first or second local signal. Preferably it is narrower than the loop bandwidth.

  As a result, the shock due to the frequency fluctuation of the first or second reference oscillation signal before and after switching is absorbed by the upstream PLL circuit, so that the downstream PLL circuit that outputs the first or second local signal is absorbed by the upstream PLL circuit. Is not enough. As a result, the loop response characteristics of the first and second PLL units can be ensured.

  In this case, the wireless communication device further includes a monitoring control unit, the active device further includes a first switch, the standby device further includes a second switch, and the monitoring control unit includes The switching control signal is output to the first or second switch, respectively, and the first switch outputs the first or second reference oscillator output from the first or second reference oscillator based on the input switching control signal. The second reference oscillation signal is supplied to the first PLL unit, and the second switch is configured to output the first or second reference output from the first or second reference oscillator based on the input switching control signal. An oscillation signal is supplied to the second PLL unit.

  In addition, a wireless communication device according to the present invention includes an active device having a first reference oscillator and a first PLL unit that outputs a first reference oscillation signal, and a second reference oscillator and a second PLL unit that output a second reference oscillation signal. And a monitoring control unit having a third PLL unit, the first PLL unit based on the input first or second reference oscillation signal and the generated first PLL oscillation signal, A first local signal that is frequency-synchronized with the first or second reference oscillation signal is generated, and the second PLL unit is configured to input the first or second reference oscillation signal and the generated second PLL oscillation signal. And generating a second local signal that is frequency-synchronized with the first or second reference oscillation signal, and the third PLL unit generates the input first reference oscillation signal and the generated third PLL. Oscillation signal The first monitor signal based on the phase comparison of the first and the second monitor signal based on the phase comparison between the input second reference oscillation signal and the third PLL oscillation signal are generated, and the monitoring control unit generates A frequency error between the first and second reference oscillation frequencies is detected based on the first and second monitor signals, and a frequency synchronization between the first and second reference oscillation signals can be obtained based on the detected frequency error. The first and second reference oscillators are controlled as described above.

  According to this configuration, since the first and second reference oscillators are controlled based on the frequency error in the monitoring control unit, the transmission-side wireless communication device and the transmission-side wireless communication device according to the related art are controlled. As a premise, it is not necessary to switch the reference oscillator as in the transmitting-side radio communication device devised by the present applicant. As a result, the active system device and the standby system device can be stably operated.

  In this case, the monitoring control unit outputs a control voltage based on the frequency error to the first and second reference oscillators, respectively, and the first and second reference oscillators are based on the input control voltage. It is preferable to adjust the frequencies of the first and second reference oscillation signals.

  The above-described wireless communication device is suitable as a wireless communication device on the transmission side of the wireless entrance system.

  According to the present invention, stable operation of an active system device and a standby system device is possible.

  A wireless communication apparatus according to the present invention and a wireless entrance system including the wireless communication apparatus will be described below with reference to the accompanying drawings, with reference to preferred embodiments. Prior to the description, the premise of the present embodiment is described. The configuration of the wireless entrance system and its problems will be described.

  First, the configuration of the wireless entrance system 50 that is a premise of the present embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is an overall block diagram of a communication system 52 including a wireless entrance system 50. FIG. 2 is a block diagram showing an internal configuration of radio entrance devices (radio communication devices) 54 and 56 arranged on the transmission side and the reception side of the radio entrance system 50, respectively.

  The wireless entrance system 50 is provided to securely connect a line wirelessly in an area (for example, between the main island and a remote island) where it is difficult to connect the line using a wired public line network or a telephone network. As shown in FIG. 1, a wireless entrance device (transmission-side wireless communication device) 54 and an antenna 58 are respectively arranged on the transmission side (left side of FIG. 1) of the communication system 52, while the reception side thereof A wireless entrance device (reception-side wireless communication device) 56 and an antenna 60 are respectively disposed on the right side of FIG. The wireless entrance device 54 is connected from the antenna 58 to the receiving-side antenna 60 and the wireless entrance device 56 via the wireless line 62.

  In addition to the wireless entrance device 54 and the antenna 58 described above, for example, a base station 64 and a multiplexer (MUX) 68 in which an antenna 66 is installed are arranged on the transmission side of the communication system 52. The multiplexer 68 and the wireless entrance device 54 are arranged. Are connected via an optical fiber cable 70.

  On the other hand, on the reception side of the communication system 52, in addition to the above-described wireless entrance device 56 and antenna 60, for example, a multiplexer 72, 74, 78, and a wireless entrance system 76 and an antenna 82 having the same configuration as the wireless entrance system 50 are installed. Each base station 80 is arranged. In this case, the wireless entrance device 56 and the multiplexer 72 are connected via an optical fiber cable 84, and the multiplexer 72 and the multiplexer 74 are connected via a public line network 86 such as a telephone line, and the multiplexer 74 and the wireless entrance system 76 are connected. Are connected via an optical fiber cable 88, and the wireless entrance system 76 and the multiplexer 78 are connected via an optical fiber cable 90.

  In this communication system 52, by using the wireless entrance systems 50 and 76, the mobile phone 94 connected to the antenna 66 of the base station 64 via the wireless line 92 and the antenna 82 of the base station 80 via the wireless line 96. It is possible to transmit transmission data such as the contents of a call between the mobile phone 98 connected in this manner.

  FIG. 2 is a block diagram showing the internal configuration of the radio entrance devices 54 and 56. The radio entrance device (not shown) of the radio entrance system 76 (see FIG. 1) has the same configuration as the radio entrance devices 54 and 56. Here, the configuration of the wireless entrance device 54 will be described as a representative.

  The wireless entrance device 54 transmits / receives an interface unit 100, a transmission active device 102a, a transmission standby device 102b, a reception active device 104a, a reception standby device 104b, and a monitoring control unit 110. Part 112.

  Here, the call contents of the caller of the mobile phone 94 (see FIG. 1) are transmitted as transmission data from the mobile phone 94 to the antenna 66 of the base station 64 via the radio line 92, and the multiplexer 68 is connected to the optical fiber cable 70. When generating a frame signal corresponding to the transmission speed (for example, STM-1) and including the transmission data, and converting the frame signal from an electrical signal to light and outputting it to the interface unit 100, the interface unit 100 The input light is converted into an electrical signal, and the transmission data included in the frame signal is output to the transmission active device 102a and the transmission standby device 102b via the hybrid unit (HYB) 120, respectively. .

  The transmission active device 102a includes a modulation unit 126a including a transmission radio frame processing unit 122a and a frame modulation unit (MOD) 124a, and a frequency conversion unit (TX) 128a. On the other hand, the standby device for transmission 102b has the same configuration as that of the active device for transmission 102a, and includes a modulation unit 126b including a transmission radio frame processing unit 122b and a frame modulation unit 124b, and a frequency conversion unit 128b. . The transmission / reception unit 112 includes a switch 130, a transmission filter 132, a reception filter 134, a low noise amplifier 136, and a hybrid unit 138.

  The transmission radio frame processing units 122a and 122b insert a frame synchronization signal into the input transmission data to generate first and second radio frames (transmission signals), respectively, and the generated first and second radios The frame is output to the frame modulators 124a and 124b. The frame modulators 124a and 124b perform digital modulation by superimposing a carrier wave signal of a predetermined frequency (for example, 400 [MHz]) on the input first and second radio frames, and the modulated first and second frames are modulated. Two radio frames are output to the frequency converters 128a and 128b. The frequency conversion units 128a and 128b convert the input first and second radio frames into signals having a frequency higher than the predetermined frequency (for example, 10 [GHz]).

  Here, when the transmission active device 102a and the transmission filter 132 are connected by the switching operation of the switch 130 by the monitoring control unit 110, the frequency conversion unit 128a converts the frequency-converted first radio frame into the switch 130. And output to the antenna 58 via the transmission filter 132. As a result, the first radio frame is transmitted as a radio wave from the antenna 58 via the radio line 62 to the antenna 60 on the receiving side.

  On the other hand, when the transmission standby system device 102b and the transmission filter 132 are connected by the switching operation of the switch 130 by the monitoring control unit 110, the frequency conversion unit 128b converts the frequency-converted second radio frame into the switch 130 and The signal is output to the antenna 58 via the transmission filter 132. As a result, the second radio frame is transmitted as a radio wave from the antenna 58 via the radio line 62 to the receiving-side antenna 60.

  On the other hand, the call contents of the caller of the cellular phone 98 (see FIG. 1) are transmitted as transmission data to the radio entrance device 56, and the first or second radio frame including the transmission data is transmitted from the antenna 60 through the radio line 62. When transmitted as a radio wave to the antenna 58, the radio frame converted from the radio wave to an electric signal by the antenna 58 passes through the reception filter 134 and is amplified by the low noise amplifier 136. The amplified radio frame is hybridized. The data are output to the reception active device 104a and the reception standby device 104b via the unit 138, respectively.

  The reception-use active device 104a includes a frequency conversion unit (RX) 140a, and a demodulation unit 146a including a frame demodulation unit (DEM) 142a and a reception radio frame processing unit 144a. On the other hand, the reception standby device 104b has the same configuration as that of the reception active device 104a, and includes a frequency conversion unit 140b, and a demodulation unit 146b including a frame demodulation unit 142b and a reception radio frame processing unit 144b. .

  Here, when the reception active device 104a and the interface unit 100 are connected by the switching operation of the switch 150 in the interface unit 100 by the monitoring control unit 110, the frequency conversion unit 140a of the reception active device 104a is: The first or second radio frame obtained by converting the input first or second radio frame into a signal (eg, 400 [MHz]) having a frequency lower than a predetermined frequency (eg, 10 [GHz]). The frame is output to the frame demodulation unit 142a. The frame demodulator 142a demodulates the input first or second radio frame and outputs the demodulated radio frame to the reception radio frame processor 144a. The reception radio frame processing unit 144a extracts the transmission data from the first or second radio frame based on the frame synchronization signal included in the input first or second radio frame, and extracts the extracted transmission data. The data is output to the interface unit 100. The interface unit 100 generates an STM-1 frame signal including the input transmission data, converts the generated frame signal from an electrical signal to light, and converts the converted light via an optical fiber cable 70. Output to the multiplexer 68.

  When the reception standby system device 104b is connected to the interface unit 100 by the switching operation of the switch 150 in the interface unit 100 by the monitoring control unit 110, the reception standby system device 104b is connected to the reception active system device 104a. Similarly, the transmission data is extracted from the received first or second radio frame, and the extracted transmission data is output to the interface unit 100.

  The monitoring control unit 110 (1) monitors and controls the interface unit 100, the transmission active device 102a, the transmission standby device 102b, the reception active device 104a, the reception standby device 104b, and the transmission / reception unit 112. (2) By controlling the switching operation of the switches 130 and 150, the device operating in the wireless entrance device 54 is changed from the active device of the transmission active device 102a and the active device of reception 104a to the standby system for transmission. Switch to the standby system of the device 102b and the reception standby system 104b, or switch from the standby system to the active system.

  The above is the description regarding the configuration of the wireless entrance system 50.

  Next, problems of the wireless entrance system 50 will be described with reference to FIGS.

  In order to ensure the reliability of the entire system, the radio entrance system 50, as shown in FIG. 2, includes an active system device for transmission 102a and an active device for reception 104a, a standby system device for transmission 102b, A set preliminary configuration including the standby system device of the reception standby system device 104b is employed. In this case, as described above, the standby devices (the standby device for transmission 102b and the reception device for transmission) are received from the active device (the active device for transmission 102a and the active device for reception 104a) by the switching operation of the switches 130 and 150. Switching to the standby system device 104b) or switching from the standby system device to the active system device is possible.

  For such switching, (1) during maintenance work of the wireless entrance device 54, switching from the active system device to the standby system device or operation from the standby system device by the operation of the supervisory control unit 110 by an operator. (2) When the active device is abnormal, the active device is automatically switched from the active device to the standby device by the switching operation of the switches 130 and 150 based on the control of the monitoring controller 110. Alternatively, there is automatic switching that switches from the standby system device to the active system device.

  Here, since the manual switching is assumed to be performed when the wireless entrance device 54 is normal, it is possible to reduce the impact on the receiving side to the wireless line 62 and the wireless entrance device 56 at the time of switching as much as possible. A switching method is required.

  Further, switching between the active system device and the standby system device is performed by transmitting side switching for switching between the active system device for transmission 102a and the standby system device for transmission 102b by the switching operation of the switch 130, and the switching operation of the switch 150. There is reception side switching for switching between the reception active device 104a and the reception standby device 104b.

  In the following description, a description will be given of the transmission-side switching in which the impact on the reception side during switching is a problem, particularly the case of switching from the transmission active device 102a to the transmission standby device 102b. In this case, it is assumed that the switch 150 on the reception side does not perform the switching operation, and the interface unit 100 is connected to the reception active device 104a and the reception standby device 104b. In addition, the first wireless frame is output from the transmission active device 102a to the transmission / reception unit 112 before switching the switch 130, and the second wireless frame is output from the transmission standby device 102b to the transmission / reception unit 112 after switching. To do.

  Furthermore, in the following description, it is assumed that the first and second radio frames are transmitted from the transmission side (the radio entrance device 54 side in FIG. 1) of the communication system 52 to the reception side (the radio entrance device 56 side in FIG. 1). explain.

  FIG. 3 shows five offset elements that cause an impact applied to the reception side {wireless entrance device 56 (see FIGS. 1 and 2)} by switching from the transmission active device 102a to the transmission standby device 102b. It is the block diagram which illustrated.

  2 and 3, when the connection between the transmission-use active device 102 a and the transmission / reception unit 112 is switched to the connection between the transmission standby-system device 102 b and the transmission / reception unit 112 by the switching operation of the switch 130, Between the first radio frame output from the transmission active device 102a to the transmission / reception unit 112 and the second radio frame output from the transmission standby device 102b to the transmission / reception unit 112, The five offset elements are generated.

  That is, the five offset elements are (1) the timing difference between the first and second radio frames in the transmission radio frame processing units 122a and 122b, and (2) the carrier signal in the frame modulation units 124a and 124b (described above). 400 [MHz] signal) frequency error and phase difference, frequency converter 128a, 128b high frequency signal (10 [GHz] signal described above) frequency error and phase difference, (3) frame modulator 124a, 124b And the delay difference between the first and second radio frames in the frequency converters 128a and 128b, (4) the switching time from the transmission active device 102a to the transmission standby device 102b, and (5) the transmission active device 102a. Power of the first radio frame output from the transmission / reception unit 112 to the transmission / reception unit 112 and the second radio frame output from the transmission standby system device 102b to the transmission / reception unit 112 Which is a deviation of the frame of power.

  The timing difference (1) described above is caused by the timing of energization from the power source (not shown) to the transmission radio frame processing units 122a and 122b. The frequency error and phase difference in (2) are caused by the wiring pattern in the frame modulators 124a and 124b and the frequency converters 128a and 128b. If such frequency error and phase difference exist, The phase difference of the second radio frame increases. The delay difference (3) is caused by the wiring pattern in the frame modulators 124a and 124b and the frequency converters 128a and 128b. If such a delay difference exists, the order of the first and second radio frames is increased. The phase difference increases. The switching time (4) is the time from the switching time of the switch 130 until the second radio frame is stabilized. The deviation of (5) is caused by the structure of the transmission active device 102a and the transmission standby device 102b.

  Therefore, in the radio entrance device 56 on the receiving side, when switching from the transmission active device 102a to the transmission standby device 102b, between the first and second radio frames due to the offset elements (1) to (5). In order to reliably absorb the phase offset and gain offset (impact) of the transmission and efficiently extract the transmission data from the first and second radio frames, the first radio frame from the transmission active device 102a and the transmission It is necessary to establish frame synchronization with the second radio frame from the standby apparatus 102b.

  The following two methods (A) and (B) are considered as a switching method on the transmission side necessary for obtaining the frame synchronization.

  In the method (A), the first and second radio frames are synchronized, the carrier frequency is synchronized, and the high frequency signal is synchronized between the transmission active device 102a and the transmission standby device 102b. The phase offset and gain offset of the first and second radio frames generated at the time of switching are minimized, and as a result, the first active device 104a for reception and the standby device 104b for reception of the first in the radio entrance device 56 And transmission data input to the frame demodulation units 142a and 142b within the holding time of the second radio frame and the synchronization holding time of the STM-1 frame signal in the interface unit 100 of the radio entrance device 56. (Hereinafter referred to as a high-speed pull-in method or hitless switching method).

  In the method (B), before the switch 130 is switched, the first radio frame is configured by inserting a switching notice signal for notifying the wireless entrance device 56 to switch the transmission data, and when the switch 130 is switched (after switching). In addition, an offset estimation signal notifying the radio entrance device 56 that the switching is completed is inserted into the transmission data to form a second radio frame, and the first and second radio frames are transmitted to the radio entrance device 56. (Hereinafter referred to as errorless switching). As a result, the demodulation units 146a and 146b of the wireless entrance device 56 can instantaneously absorb the phase offset and gain offset generated at the time of switching on the receiving side, and the interface unit 100 includes the STM-1 including the transmission data. It is possible to prevent the occurrence of an error when generating the frame signal.

  However, the high-speed pull-in method (A) does not require a sequence between transmission and reception, and has an advantage that an error frequent occurrence time of an STM-1 frame signal is shortened. And a change in the propagation path due to rainfall, etc.) and the hardware configuration for synchronizing the carrier frequency and the high-frequency signal is complicated.

  On the other hand, the error-less switching method of (B) has an advantage that the quality of the wireless line 62 at the time of switching is ensured, but it is easily influenced by the state of the wireless line 62 as in the high-speed pull-in method of (A). In addition, the hardware configuration for synchronizing the carrier frequency and the high-frequency signal is complicated, and the switching sequence is complicated.

  Furthermore, in (A) and (B), the above-mentioned (1) to (5) that occur when the switch 130 is switched as the modulation scheme of the first and second radio frames is a multilevel modulation scheme and has a higher symbol rate. ), It is difficult to cope with the offset element.

  Therefore, regardless of the modulation schemes of the first and second radio frames, the offsets (phase offsets and phase offsets) of the first and second radio frames generated before and after switching from the active device for transmission 102a to the standby device for transmission 102b. A wireless entrance system that can efficiently absorb (gain offset) by the wireless entrance device 56 on the receiving side is desired.

  The above is the description regarding the problem of the wireless entrance system 50.

  Next, the wireless entrance system 160 according to the present embodiment will be described with reference to FIG. Note that the wireless entrance system 50 (see FIGS. 1 to 3) that is the premise of the present embodiment, the transmission-side wireless communication devices 2 and 9 (see FIGS. 7 and 8) according to the prior art, and the present applicant have proposed. Constituent elements that are the same as the constituent elements of the transmitting wireless communication device 15 (see FIG. 9) that have been issued are assigned the same reference numerals, and detailed descriptions thereof are omitted.

  This wireless entrance system 160 is a system that adopts the above-mentioned (A) high-speed pull-in method and improves the drawbacks of (A). As shown in FIG. A first PLL unit 164a in which an oscillator 14a, a first switch 16a, and two PLL circuits 8a and 162a are cascade-connected is disposed, respectively, while the transmission standby system device 102b includes a second reference oscillator 14b, a second PLL The wireless entrance system 50 (see FIGS. 1 to 3), which is the premise of the present embodiment, is that the second PLL unit 164b in which the switch 16b and the two PLL circuits 8b and 162b are cascade-connected is disposed. Different.

  FIG. 4 is a block diagram showing a characteristic configuration of the transmission active device 102a and the transmission standby device 102b of the wireless entrance devices 54 and 56 in the wireless entrance system 160 according to the present embodiment. Components similar to those of the wireless entrance system 50 that is the premise of the present embodiment described with reference to FIGS. 1 to 3 are partially omitted. In the wireless entrance devices 54 and 56, it is assumed that the various synchronizations described above are established between the transmission active device 102a and the transmission standby device 102b.

  First, the configurations of the first and second reference oscillators 14a and 14b, the first and second switches 16a and 16b, and the first and second PLL units 164a and 164b will be described with reference to FIG.

  The first reference oscillator 14a outputs the first reference oscillation signal to the first and second switches 16a and 16b, respectively, while the second reference oscillator 14b outputs the second reference oscillation signal to the first and second switches 16a. , 16b, respectively.

  The first switch 16a receives the first or second reference oscillation signal output from the first or second reference oscillator 14a, 14b based on a switching signal from the monitoring control unit 110 (see FIG. 2) as a first PLL unit. On the other hand, the second switch 16b supplies the input first or second reference oscillation signal to the second PLL unit 164b based on the input switching signal. Accordingly, the first or second reference oscillation signal is input to the first and second PLL units 164a and 164b.

  The PLL circuit 162a of the first PLL unit 164a includes a phase comparison unit 166a, a low pass filter (LPF) 168a, and a PLL oscillation unit 170a. The phase comparison unit 166a compares the phase of the input first or second reference oscillation signal with the PLL oscillation signal (first PLL oscillation signal) generated by the PLL oscillation unit 170a, and the comparison result is passed through the LPF 168a. Output to the PLL oscillator 170a. Based on the comparison result, the PLL oscillation unit 170a synchronizes the frequency of the first or second reference oscillation signal and the PLL oscillation signal, and the PLL oscillation signal obtained by the frequency synchronization is output to the PLL circuit 8a and the phase. Each is output to the comparison unit 166a.

  The PLL circuit 8a compares the input PLL oscillation signal with a PLL oscillation signal (first PLL oscillation signal) generated by its own internal oscillation unit (not shown) and compares the input PLL oscillation signal with the self PLL oscillation signal. The frequency synchronization with the PLL oscillation signal is taken, and the PLL oscillation signal with the frequency synchronization taken is output to the frame modulation unit 124a or the frequency conversion unit 128a (see FIG. 4) as a first local signal.

  On the other hand, the PLL circuit 162b of the second PLL unit 164b has the same configuration as the PLL circuit 162a, and includes a phase comparison unit 166b, an LPF (low pass filter) 168b, and a PLL oscillation unit 170b. The phase comparison unit 166b compares the phase of the input first or second reference oscillation signal with the PLL oscillation signal (second PLL oscillation signal) generated by the PLL oscillation unit 170b, and compares the comparison result via the LPF 168b. Output to the PLL oscillator 170b. Based on the comparison result, the PLL oscillation unit 170b synchronizes the frequency of the first or second reference oscillation signal and the PLL oscillation signal, and the PLL oscillation signal that is synchronized with the PLL circuit 8b and the phase Each is output to the comparison unit 166b.

  Similarly to the PLL circuit 8a, the PLL circuit 8b compares the input PLL oscillation signal with the PLL oscillation signal (second PLL oscillation signal) generated by its own internal oscillation unit (not shown) and inputs the input PLL oscillation signal. The PLL oscillation signal and the own PLL oscillation signal are frequency-synchronized, and the PLL oscillation signal of the self-synchronized PLL oscillation signal is used as a second local signal in the frame modulation unit 124b or the frequency conversion unit 128b (see FIG. 4). Output.

  Here, the loop bandwidth of the upstream PLL circuit 162a, 162b arranged on the first or second switch 16a, 16b side is the downstream PLL circuit 8a, 8b that outputs the first or second local signal. It is preferable to make it narrower than the loop bandwidth. Specifically, the loop bandwidth of the PLL circuits 162a and 162b is preferably 1/100 or less of the loop bandwidth of the PLL circuits 8a and 8b.

  In the transmission active system device 102a and the transmission standby system device 102b, when the switching signals are simultaneously output to the first and second switches 16a and 16b from the monitoring control unit 110 (see FIG. 2), The second reference oscillators 14a, 14b and the first and second switches 16a, 16b are connected, and the first or second reference oscillation signal output from the first or second reference oscillator 14a, 14b is the first and second reference oscillation signals. 2 are supplied to the first and second PLL sections 164a and 164b via the switches 16a and 16b, respectively.

  In the first PLL unit 164a, the upstream PLL circuit 162a outputs the PLL oscillation signal that is frequency-synchronized with the input first or second reference oscillation signal to the downstream PLL circuit 8a, and the downstream PLL circuit 162a The PLL circuit 8a outputs a first local signal whose frequency is synchronized with the input PLL oscillation signal to the frame modulation unit 124a or the frequency conversion unit 128a (see FIG. 2).

  When the output destination of the first local signal is the frame modulation unit 124a, the frame modulation unit 124a superimposes the input first local signal as a carrier signal on the first radio frame, and the first radio frame Modulate. On the other hand, when the output destination of the first local signal is the frequency converter 128a, the frequency converter 128a superimposes the input first local signal as a high frequency signal on the modulated first radio frame. The first radio frame is frequency-converted.

  On the other hand, in the second PLL unit 164b, the upstream PLL circuit 162b outputs the PLL oscillation signal that is frequency-synchronized with the input first or second reference oscillation signal to the downstream PLL circuit 8b, and is downstream. The PLL circuit 8b on the side outputs the second local signal synchronized in frequency with the input PLL oscillation signal to the frame modulation unit 124b or the frequency conversion unit 128b (see FIG. 2).

  When the output destination of the second local signal is the frame modulation unit 124b, the frame modulation unit 124b superimposes the input second local signal as a carrier signal on the second radio frame, and the second radio frame Modulate. On the other hand, when the output destination of the second local signal is the frequency converter 128b, the frequency converter 128b superimposes the input second local signal as a high frequency signal on the modulated second radio frame. The second radio frame is frequency converted.

  In FIG. 4, the first local signal is output to the frame modulation unit 124a or the frequency conversion unit 128a (see FIG. 2), and the second local signal is output to the frame modulation unit 124b or the frequency conversion unit 128b. .

  Here, when outputting the first local signals to the frame modulation unit 124a and the frequency conversion unit 128a, two PLL units 164a are arranged in the transmission active device 102a, and the output side (downstream) of the PLL circuit 162a is arranged. Two PLL sections 164a are connected in parallel. In this case, the frame modulation unit 124a is connected to one PLL unit 164a, and the frequency conversion unit 128a is connected to the other PLL unit 164a.

  On the other hand, when outputting the second local signals to the frame modulation unit 124b and the frequency conversion unit 128b, two PLL units 164b are arranged in the transmission standby system device 102b, and the output side (downstream side) of the PLL circuit 162b is arranged. ) Are connected in parallel to the two PLL units 164b. In this case, the frame modulation unit 124b is connected to one PLL unit 164b, and the frequency conversion unit 128b is connected to the other PLL unit 164b.

  Next, with reference to the block diagram of FIG. 4 and the step response characteristics of FIGS. 5A and 5B regarding the effects of the wireless entrance system 160 according to the present embodiment and the wireless entrance devices 54 and 56 constituting the wireless entrance system 160. While explaining.

  5A and 5B show the step response characteristics of the first and second PLL units 164a and 164b with respect to the switching of the first and second switches 16a and 16b. The characteristics shown by the solid line in FIG. 5A are the first and second PLLs. FIG. 5A shows the step response characteristics when the sections 164a and 164b are configured only by the PLL circuits 8a and 8b. The characteristics indicated by the dotted lines in FIG. 5B is a step response characteristic of the present embodiment in which the first and second PLL units 164a and 164b are configured by the PLL circuits 8a and 8b and the PLL circuits 162a and 162b.

  As shown by the solid line in FIG. 5A, when the first and second PLL sections 164a and 164b (see FIG. 4) are configured only by the PLL circuits 8a and 8b, immediately after the switching operation of the first and second switches 16a and 16b. In (time is close to 0), the frequency of the first and second local signals varies rapidly with time. As a result, the first and second PLL units 164a and 164b receive a large impact due to switching of the first and second switches 16a and 16b.

  On the other hand, as shown by a dotted line in FIG. 5A, when the first and second PLL sections 164a and 164b (see FIG. 4) are configured only by the PLL circuits 162a and 162b, the loop bandwidth of the PLL circuits 162a and 162b is reduced to the PLL circuit. Since it is narrower than the loop bandwidth of 8a and 8b, after the switching operation of the first and second switches 16a and 16b, the frequency of the PLL oscillation signal fluctuates gradually with time.

  Accordingly, in the present embodiment, the first and second switches 16a, 164b (see FIG. 4) are internally connected to the PLL circuits 162a, 162b and the PLL circuits 8a, 8b, so that the first and second switches 16a, After the switching operation of 16b, the frequency of the PLL oscillation signal can be gradually changed with respect to the time change.

  As described above, in the wireless entrance devices 54 and 56 and the wireless entrance system 160 according to the present embodiment, the first and second reference oscillation signals supplied to the first and second PLL units 164a and 164b are used as the first and second switches. The frequency of the first and second reference generation signals when the first reference oscillation signal is switched from the first reference oscillation signal to the second reference oscillation signal or from the second reference oscillation signal to the first reference oscillation signal by 16a and 16b. Even if the fluctuation occurs, the PLL circuits 162a and 162b and the PLL circuits 8a and 8b are connected in cascade, so that the shock due to the frequency fluctuation can be absorbed by the PLL circuits 8a, 8b, 162a and 162b.

  Also, the PLL circuits 8a, 8b, 162a, 162b that operate in the frequency bands of the first and second reference oscillation signals and the PLL oscillation signal can be configured with devices having high C / N and low cost. It becomes possible to realize the PLL circuits 8a, 8b, 162a and 162b which are C / N and minimize the impact.

  Therefore, in this embodiment, compared with the transmission side wireless communication devices 2 and 9 according to the prior art and the transmission side wireless communication device 15 devised by the present applicant on the assumption of the transmission side wireless communication devices 2 and 9. Thus, stable operation of the transmission active device 102a and the transmission standby device 102b before and after the switching becomes possible.

  Furthermore, by making the loop bandwidth of the upstream PLL circuits 162a and 162b narrower than the loop bandwidth of the downstream PLL circuits 8a and 8b, the frequency fluctuation of the first or second reference oscillation signal before and after switching The shock can be absorbed by the upstream PLL circuits 162a and 162b. As a result, the downstream PLL circuits 8a and 8b that output the first or second local signal are not affected by the impact, so that the loop response characteristics of the first and second PLL units 164a and 164b can be ensured. it can.

  In the above description, the PLL circuits 8a and 162a are vertically connected in the transmission active device 102a, and the PLL circuits 8b and 162b are vertically connected in the transmission standby device 102b. Instead of this configuration, as shown in FIG. 6, a PLL circuit (third PLL unit) 180 may be arranged inside the monitoring control unit 110.

  In this case, in the transmission-use active device 102a, the first PLL section is configured only by the PLL circuit 8a, while in the transmission standby system device 102b, the second PLL section is configured only by the PLL circuit 8b. In addition, a D / A converter 198a is disposed in the transmission active device 102a, while a D / A converter 198b is disposed in the transmission standby device 102b.

  The monitoring control unit 110 includes the PLL circuit 180, the A / D converter 192, the CPU 194, and the switch 196 described above. The PLL circuit 180 includes a phase comparator 182, an LPF 184, a PLL oscillator 186, and 1 / N frequency dividers 188 and 190.

  The switch 196 of the monitoring control unit 110 alternately switches the connection between the first reference oscillator 14a and the PLL circuit 180 or the connection between the second reference oscillator 14b and the PLL circuit 180 at predetermined time intervals.

  Here, when the first reference oscillation signal output from the first reference oscillator 14a is supplied to the PLL circuit 180 via the switch 196 by the switching operation of the switch 196, the 1 / N frequency dividing unit 190 causes the first reference oscillation signal to be output from the first reference oscillator 14a. The 1 reference oscillation signal is divided by a 1 / N division ratio and output to the phase comparison unit 182, while the 1 / N division unit 188 outputs the PLL oscillation signal output from the PLL oscillation unit 186 by 1 The frequency is divided by a frequency division ratio of / N and output to the phase comparator 182.

  The phase comparison unit 182 compares the phase of the first reference oscillation signal and the PLL oscillation signal that are input after being divided by a 1 / N division ratio, and performs PLL oscillation through the LPF 184 using the comparison result as a monitor signal. Output to the unit 186 and the A / D converter 192, respectively. The PLL oscillator 186 outputs a PLL signal that is frequency-synchronized with the first reference oscillation signal based on the monitor signal. On the other hand, the A / D converter 192 digitally converts the monitor signal and outputs it to the CPU 194.

  On the other hand, when the second reference oscillation signal output from the second reference oscillator 14b is supplied to the PLL circuit 180 via the switch 196 by the switching operation of the switch 196, the 1 / N frequency divider 190 causes the second reference oscillation signal 190 to be The reference oscillation signal is divided by a 1 / N division ratio and output to the phase comparison unit 182. The phase comparison unit 182 divides the reference oscillation signal by the 1 / N division ratio and inputs the second reference. The phases of the oscillation signal and the PLL oscillation signal from the PLL oscillation unit 186 are compared, and the comparison result is output as a monitor signal to the PLL oscillation unit 186 and the A / D converter 192 via the LPF 184.

  The PLL oscillator 186 outputs a PLL signal that is frequency-synchronized with the second reference oscillation signal based on the monitor signal. On the other hand, the A / D converter 192 digitally converts the monitor signal and outputs it to the CPU 194.

  The CPU 194 compares the inputted monitor signals to detect a frequency error between the first and second reference oscillation frequencies, and based on the detected frequency error, the CPU 194 compares the first and second reference oscillation signals. A control voltage for frequency synchronization is output as a digital signal to each of the transmission active device 102a and the transmission standby device 102b.

  The D / A converters 198a and 198b convert the inputted digital signals into analog signals and output the analog signals to the first and second reference oscillators 14a and 14b.

  The first and second reference oscillators 14a and 14b adjust the frequency of the first and second reference oscillation signals based on the input control voltage. As a result, frequency synchronization of the first and second reference oscillation signals can be achieved.

  As described above, when the control voltage is output from the monitoring controller 110 to the first and second reference oscillators 14a and 14b to adjust the frequencies of the first and second reference oscillation signals, the first and second reference oscillators 14a are provided. , 14b to the PLL circuits 8a, 8b are not required to be switched, so that the stable operation of the transmission active device 102a and the transmission standby device 102b is ensured even in this method. It becomes possible.

  Of course, the wireless communication apparatus according to the present invention and the wireless entrance system including the wireless communication apparatus are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. .

It is a block diagram of the communication system containing the radio | wireless entrance system used as the premise of this embodiment. It is a block diagram of the radio | wireless entrance apparatus of FIG. It is a block diagram which shows the offset element which generate | occur | produces by switching from the active apparatus for transmission to the standby apparatus for transmission. It is a partial block diagram which shows the structure of the radio | wireless entrance apparatus which concerns on this embodiment. FIG. 5A is a graph showing the step response characteristics when the PLL unit of FIG. 4 is configured by one PLL circuit, and FIG. 5B is a graph showing the step response characteristics of the PLL unit of FIG. It is a partial block diagram which shows the other structure of the radio | wireless entrance apparatus which concerns on this embodiment. It is a block diagram of the radio | wireless communication apparatus which concerns on a prior art. It is a block diagram of the other radio | wireless communication apparatus which concerns on a prior art. FIG. 9 is a block diagram of a wireless communication device devised by the present applicant based on the wireless communication devices of FIGS. 7 and 8.

Explanation of symbols

8a, 8b, 162a, 162b, 180 ... PLL circuit 14a ... first reference oscillator 14b ... second reference oscillator 16a ... first switch 16b ... second switch 54, 56 ... wireless entrance device 102a ... active device for transmission 102b ... Standby system for transmission 160 ... Wireless entrance system 164a ... First PLL section 164b ... Second PLL sections 166a, 166b, 182 ... Phase comparison sections 168a, 168b, 184 ... LPF 170a, 170b ... PLL oscillation section

Claims (6)

A first reference oscillator that outputs a first reference oscillation signal and an active device having a first PLL unit in which a plurality of PLL circuits are connected in cascade; a second reference oscillator that outputs a second reference oscillation signal; and a plurality of PLL circuits. A standby system device having a second PLL unit connected in cascade,
The first PLL unit generates a frequency of the first or second reference oscillation signal based on the input first or second reference oscillation signal and the first PLL oscillation signal generated in each PLL circuit of the first PLL unit. Generating a synchronized first local signal,
The second PLL unit generates a frequency of the first or second reference oscillation signal based on the input first or second reference oscillation signal and the second PLL oscillation signal generated in each PLL circuit. A wireless communication device that generates a synchronized second local signal. The wireless communication device according to claim 1, wherein
The loop bandwidth of the upstream PLL circuit connected to the first or second reference oscillator in the first and second PLL units is the loop bandwidth of the downstream PLL circuit that outputs the first or second local signal. A wireless communication device characterized by being narrower. The wireless communication apparatus according to claim 1 or 2,
The wireless communication device further includes a monitoring control unit,
The active device further includes a first switch;
The standby system apparatus further includes a second switch,
The monitoring control unit outputs a switching control signal to the first or second switch,
The first switch supplies the first or second reference oscillation signal output from the first or second reference oscillator to the first PLL unit based on the input switching control signal,
The second switch supplies the first or second reference oscillation signal output from the first or second reference oscillator to the second PLL unit based on the input switching control signal. Wireless communication device. An active system device having a first reference oscillator and a first PLL unit for outputting a first reference oscillation signal, a standby system device having a second reference oscillator and a second PLL unit for outputting a second reference oscillation signal, and a third PLL unit A monitoring control unit having
The first PLL unit has a first local frequency synchronized with the first or second reference oscillation signal based on the input first or second reference oscillation signal and the generated first PLL oscillation signal. Generate a signal,
The second PLL unit has a second local frequency synchronized with the first or second reference oscillation signal based on the input first or second reference oscillation signal and the generated second PLL oscillation signal. Generate a signal,
The third PLL unit includes a first monitor signal based on a phase comparison between the input first reference oscillation signal and the generated third PLL oscillation signal, and the input second reference oscillation signal and the third PLL oscillation signal. A second monitor signal based on a phase comparison with
The monitoring control unit detects a frequency error of the first and second reference oscillation frequencies based on the generated first and second monitor signals, and based on the detected frequency error, the first and second The wireless communication apparatus, wherein the first and second reference oscillators are controlled so that a frequency synchronization of a reference oscillation signal can be obtained. The wireless communication device according to claim 4, wherein
The supervisory control unit outputs a control voltage based on the frequency error to the first and second reference oscillators, respectively.
The wireless communication apparatus, wherein the first and second reference oscillators adjust the frequencies of the first and second reference oscillation signals based on the input control voltage.   A wireless entrance system comprising the wireless communication apparatus according to claim 1 as a wireless communication apparatus on a transmission side.

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