JP2006303837A - Radio base station devices and method for controlling frequency used for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio base station devices, capable of automatically controlling the frequency of an oscillator, without having to conducting control on site and obstructing working. <P>SOLUTION: When a CPU informs of the start of working of own device, a starting circuit 5 operates the internal timer function. When the starting circuit 5 times an arbitrary time T, a crystal oscillator 8 is supplied with a power supply, while the CPU 1 is also informed of the start of the supply of the power supply to the crystal oscillator 8. The CPU 1 compares the phase of an output signal from a temperature compensating type crystal oscillator 6, while using the output signal from the crystal oscillator 8 as a reference, and computes the control value of the frequency from the result of the comparison. The CPU 1 actually computes a frequency control to the temperature compensation type crystal oscillator 6 from the control value, a temperature from a temperature sensor 2, a reference value conserved in a memory 3 and a temperature change value, and applies a control voltage to the temperature compensating type crystal oscillator 6 via a D/A converter 7. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio base station apparatus and a frequency adjustment method used therefor, and more particularly, to a frequency adjustment method for an oscillator mounted on the radio base station apparatus.

  Conventionally, in a radio base station apparatus, as shown in FIG. 9, an antenna 61, a duplexer 62, a receiver 63, a transmitter 64, a D / A (digital / analog) converter 65, and a crystal oscillator 66, a synthesizer 67, a control unit 68, a frequency adjustment unit 69, a memory 70, and a mode setting unit 71.

  The transmitter 64 converts the frequency of the transmission signal into a transmission frequency, and amplifies it to a predetermined transmission power. The duplexer 62 suppresses unnecessary waves of the transmission signal, and suppresses unnecessary waves of signals received by the antenna 61 described later. The antenna 61 transmits a transmission signal and receives a reception signal.

  The receiver 63 performs frequency conversion and band limitation, and converts to a baseband signal. The control unit 68 generates a modulated transmission baseband signal and demodulates the received baseband signal. Further, the control unit 68 generates data of a D / A converter 65 described later.

  The D / A converter 65 converts data from the control unit 68 into a DC voltage. The crystal oscillator 66 receives voltage control from the D / A converter 65 and outputs an oscillation frequency with high frequency stability. The synthesizer 67 generates a local signal for frequency conversion of the transmitter 64 and the receiver 63 with the frequency output from the crystal oscillator 66 as a reference.

  The frequency adjustment unit 69 is composed of a variable resistor or the like, and adjusts the oscillation frequency of the crystal oscillator 66 via the control unit 68 and the D / A converter 65. The memory 70 stores control voltage information corresponding to the crystal oscillator 66. The mode setting unit 71 sets the test mode when the frequency of the crystal oscillator 66 is adjusted.

  On the other hand, a conventional radio base station apparatus for mobile communication is synchronized with a clock signal sent from a transmission path connected to the radio base station control apparatus. Since the radio base station controller uses fewer oscillators than the radio base station equipment and uses an oscillator with high frequency stability, the clock signal of the transmission path sent from this radio base station controller If synchronized, the oscillator of the radio base station apparatus can also keep the frequency stability high.

  However, Ethernet (registered trademark) using the IP (Internet Protocol) protocol for the transmission path between the radio base station apparatus and the radio base station control apparatus because of the fact that it is possible to reduce the operating cost (running cost). ) May be used.

  In this case, since the clock signal cannot be sent to the transmission line, the frequency stability is high for the oscillator built in the radio base station apparatus as well as the radio base station control apparatus, and the secular change during the operation period Is also required to be within an acceptable range. Since an oscillator with high frequency stability is expensive, it is uneconomical to install in a radio base station apparatus with a large number of operating units, resulting in an increase in equipment cost. In view of this, there has been proposed a method of going to a place where a radio base station apparatus is installed and easily adjusting frequency fluctuation due to secular change (see, for example, Patent Document 1).

Japanese Patent No. 3034319

  The conventional frequency adjustment method described above has a problem that it cannot be adjusted during operation because mode setting is performed. Further, in the conventional frequency adjustment method, since the frequency adjustment unit is composed of a variable resistor or the like, there is also a problem that it is necessary to perform adjustment on-site manually. Furthermore, in the conventional frequency adjustment method, there is a problem that a measuring instrument for measuring the frequency has to be prepared because the transmission signal output from the antenna is used when performing the frequency adjustment.

  On the other hand, in the method described in Patent Document 1, it is necessary to go to the place where the radio base station apparatus is installed, and it is necessary to switch to the test mode in the standby state, and during that time, the operation must be stopped. There's a problem.

  Therefore, an object of the present invention is to solve the above-mentioned problems, and to use the radio base station apparatus capable of automatically adjusting the frequency of the oscillator without going to the site and performing the adjustment without interfering with the operation. The object is to provide a frequency adjustment method.

  A radio base station apparatus according to the present invention is a radio base station apparatus that uses an oscillator whose oscillation frequency fluctuates over time, timer means for detecting the elapse of an arbitrary preset time, and the timer means A second oscillator that is activated when the arbitrary time is detected, and a unit that adjusts a secular change of the oscillator based on a signal oscillated from the second oscillator.

  The frequency adjustment method according to the present invention is a frequency adjustment method used for a radio base station apparatus that uses an oscillator whose oscillation frequency fluctuates over time, and the radio base station apparatus passes a predetermined arbitrary time. , A process of starting the second oscillator when the arbitrary time is detected, and a process of adjusting the secular change of the oscillator based on a signal oscillated from the second oscillator is doing.

  That is, the radio base station apparatus of the present invention pays attention to the fact that the secular change proceeds with the energization time of the oscillator, and the time when the frequency fluctuation due to the secular change of the radio base station apparatus exceeds the allowable value is determined from the characteristics of the oscillator to be used Estimate and start another oscillator with the timer function in the startup circuit after an arbitrary time has elapsed, and the oscillator used in the radio base station apparatus based on this oscillator that has not changed over time By adjusting the secular change of the oscillator, the frequency fluctuation due to the secular change of the oscillator is automatically adjusted so as not to disturb the operation.

  Thereby, in the radio base station apparatus of the present invention, the oscillator used in the radio base station apparatus for mobile communication can be automatically adjusted so as not to hinder the operation of the frequency fluctuation of the oscillator over time. It is characterized by that.

  More specifically, in the radio base station apparatus of the present invention, a temperature compensated crystal oscillator is used as a reference oscillator in its own apparatus, and the oscillation frequency is adjusted by applying a DC voltage to the temperature compensated crystal oscillator. This makes it possible to output signals with high frequency stability.

  In the radio base station apparatus of the present invention, in addition to the temperature-compensated crystal oscillator, a crystal oscillator is provided, and the oscillation frequency can be adjusted by applying a DC voltage to the crystal oscillator. A reference signal for adjusting the frequency of the oscillator is output.

  Furthermore, in the radio base station apparatus of the present invention, the first D / A (digital / analog) converter that outputs a DC voltage for adjusting the oscillation frequency of the temperature-compensated crystal oscillator and the oscillation frequency of the crystal oscillator are adjusted. And a second D / A converter that outputs a direct-current voltage.

  A CPU (central processing unit) in the radio base station apparatus generates and outputs data of the first D / A converter from values of a temperature sensor and a first memory, which will be described later. The data of the second D / A converter is generated from the value of the second memory and output.

  The temperature sensor detects the temperature in the device itself and reports the temperature to the CPU. The first memory stores the relationship between the oscillation frequency at an arbitrary constant temperature of the temperature compensated crystal oscillator and the DC voltage output from the first D / A converter as a data string, and the temperature of the temperature compensated crystal oscillator. The relationship between the DC voltage output from the first D / A converter with respect to the fluctuation is stored as a data string. The second memory stores the relationship between the oscillation frequency of the crystal oscillator at an arbitrary constant temperature and the DC voltage output from the second D / A converter as a data string, and the second D against the temperature fluctuation of the crystal oscillator. The relationship of the DC voltage output from the / A converter is stored as a data string. The activation circuit has a timer and activates the power source of the crystal oscillator according to a command from the CPU.

As described above, in the radio base station apparatus of the present invention, maintenance is performed by automatically adjusting the frequency variation due to the secular change of the temperature compensated crystal oscillator using the crystal oscillator activated at an arbitrary time by the activation circuit. It is possible to automatically adjust the frequency without going out to the place where the device is installed and without interfering with the operation.

  By adopting the configuration and operation as described below, the present invention provides an effect that the frequency of the oscillator can be automatically adjusted without performing the adjustment on site and without disturbing the operation.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a radio base station apparatus for mobile communication according to an embodiment of the present invention. In FIG. 1, a radio base station apparatus according to an embodiment of the present invention includes a CPU (central processing unit) 1, a temperature sensor 2, memories 3 and 4, a startup circuit 5, a temperature compensation crystal oscillator 6, and a D / A converters 7 and 9 and a crystal oscillator 8.

  The temperature-compensated crystal oscillator 6 is used as a reference oscillator in its own device (wireless base station device for mobile communication according to an embodiment of the present invention), and the oscillation frequency can be adjusted by applying a DC voltage. And outputs a signal with high frequency stability. The crystal oscillator 8 can adjust the oscillation frequency by applying a DC voltage, and outputs a reference signal when adjusting the frequency of the temperature compensated crystal oscillator 6. The frequency stability of the signal is a temperature compensated type. Lower than crystal oscillator 6.

  The D / A converter 7 outputs a DC voltage for adjusting the oscillation frequency of the temperature compensated crystal oscillator 6. The D / A converter 9 outputs a DC voltage for adjusting the oscillation frequency of the crystal oscillator 8.

  The CPU 1 generates and outputs data of the D / A converter 7 from the values of the temperature sensor 2 and the memory 3, and generates and outputs data of the D / A converter 9 from the values of the temperature sensor 2 and the memory 4. The temperature sensor 2 detects the temperature in the device itself and reports the temperature to the CPU 1.

  The memory 3 stores the relationship between the oscillation frequency of the temperature-compensated crystal oscillator 6 at an arbitrary constant temperature and the DC voltage output from the D / A converter 7 as a data string, and against the temperature variation of the temperature-compensated crystal oscillator 6. The relation of the DC voltage output from the D / A converter 7 is stored as a data string.

  The memory 4 stores the relationship between the oscillation frequency of the crystal oscillator 8 at an arbitrary constant temperature and the DC voltage output from the D / A converter 9 as a data string, and from the D / A converter 9 with respect to the temperature fluctuation of the crystal oscillator 8. The relationship of the output DC voltage is stored as a data string. The activation circuit 5 includes a timer (not shown), and activates the power source of the crystal oscillator 8 according to a command from the CPU 1.

  FIG. 2 is a block diagram showing the configuration of the CPU 11 of FIG. In FIG. 2, the CPU 1 includes a data generation unit 11, a switching unit 12, and a frequency adjustment unit 13. The data generation unit 11 generates data for controlling the D / A converter 7 from the temperature from the temperature sensor 2 and the data string stored in the memory 3. The frequency adjustment unit 13 compares the frequencies of the temperature-compensated crystal oscillator 6 and the crystal oscillator 8 to calculate a frequency adjustment value, and generates data for controlling the D / A converter 7.

  The switching unit 12 selects and outputs data output from the data generation unit 11 during normal operation, and selects and outputs data output from the frequency adjustment unit 13 during adjustment. It has a function to switch between data and data when performing frequency adjustment.

  FIG. 3 is a block diagram showing a configuration of the activation circuit 5 of FIG. In FIG. 3, the starting circuit 5 includes a timer circuit 51 and a power supply control circuit 52. The timer circuit 51 calculates a time calculation using a signal from the CPU 1 as a trigger, and sends a message to the power supply control circuit 52 after an arbitrary time has elapsed. As a time calculation method, there is a hardware or software implementation method with an arbitrary set time. The power supply control circuit 52 is a power supply circuit for the crystal oscillator 8 and supplies power to the crystal oscillator 8 when receiving a signal from the timer circuit 51.

  FIG. 4 is a block diagram showing a configuration of a portion of the CPU 1 shown in FIG. 1 that is not shown in FIG. In FIG. 4, the data generation unit 21 generates data for controlling the D / A converter 9 from the temperature from the temperature sensor 2 and the data string stored in the memory 4.

  FIG. 5 is a block diagram showing a configuration of the frequency adjustment unit 13 of FIG. In FIG. 5, the frequency adjustment unit 13 includes a comparison unit 131, an adjustment value calculation unit 132, and a data generation unit 133.

  The comparison unit 131 compares the oscillation frequency of the temperature compensated crystal oscillator 6 with the oscillation frequency of the crystal oscillator 8. The adjustment value calculation unit 132 calculates a voltage value for adjusting the frequency of the temperature compensated crystal oscillator 6 from the difference between the oscillation frequency of the temperature compensated crystal oscillator 6 and the oscillation frequency of the crystal oscillator 8 obtained by the comparison unit 131. calculate. The data generation unit 133 generates data for controlling the D / A converter 7 from the temperature from the temperature sensor 2 and the data string stored in the memory 3.

  In the above-described embodiment of the present invention, each component in the CPU 1 is configured as a functional classification, and therefore, it does not matter whether it is hardware or software. Similarly, each component in the activation circuit 5 is also configured as a functional classification, so that it does not matter whether it is hardware or software.

  FIG. 6 is a diagram showing the relationship between the detection value of the temperature sensor 2 of FIG. 1 and the temperature adjustment for the temperature compensated crystal oscillator 6 according to one embodiment of the present invention, and FIG. 7 is the data by the data generation unit 133 of FIG. It is a figure for demonstrating production | generation. The temperature adjustment for the temperature compensated crystal oscillator 6 according to one embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, the voltage value of the D / A converter 7 is determined so that the temperature compensated crystal oscillator 6 is output at a desired oscillation frequency. First, the CPU 1 detects the temperature in its own device by the temperature sensor 2. Next, the CPU 1 sends DC voltage data to be applied to the temperature compensated crystal oscillator 6 to the D / A converter 7. In the present embodiment, while changing the output voltage value of the D / A converter 7, the oscillation frequency output from the temperature compensated crystal oscillator 6 is set to a desired frequency.

  When the desired oscillation frequency is reached, the CPU 1 stores the data sent to the D / A converter 7 and the value (detected temperature) of the temperature sensor 2 in the memory 3 at that time. The value at this time is “reference value # 1” (see FIG. 6). As an example, “reference value # 1” is “temperature sensor 2 value: 30 ° C.” and “D / A converter 12 output value: 1.0 V”.

  Subsequently, the CPU 1 stores the oscillation frequency fluctuation value due to the temperature fluctuation of the temperature compensated crystal oscillator 6 in the memory 3. In the present invention, the oscillation frequency due to temperature fluctuation of the temperature compensated crystal oscillator 6 is confirmed in advance, and the value is stored in the memory 3. The value at this time is “temperature fluctuation value # 1” (see FIG. 6).

  Similarly, the CPU 1 determines the voltage value of the D / A converter 9 so that the crystal oscillator 8 is output at a desired oscillation frequency. First, the power supply of the crystal oscillator 8 is stopped by the start circuit 5 when the own apparatus is started. Therefore, the CPU 1 sends a signal A to the activation circuit 5. When the activation circuit 5 receives the signal A, it immediately starts supplying power to the crystal oscillator 8.

  Next, the CPU 1 detects the temperature in the device itself with the temperature sensor 2, and sends the data of the DC voltage applied to the crystal oscillator 8 to the D / A converter 9. The CPU 1 sets the oscillation frequency output from the crystal oscillator 8 to a desired frequency while changing the output voltage value of the D / A converter 9. When the desired oscillation frequency is reached, the CPU 1 stores the data sent to the D / A converter 9 and the value (detected temperature) of the temperature sensor 2 in the memory 4 at that time. The value at this time is referred to as “reference value # 2.” As an example, “reference value 2” is “value of temperature sensor 2: 30 ° C.” and “output value of D / A converter 9: 1.5 V”.

  Subsequently, the CPU 1 stores the oscillation frequency fluctuation value due to the temperature fluctuation of the crystal oscillator 8 in the memory 4. In this embodiment, the oscillation frequency due to temperature fluctuation of the crystal oscillator 8 is confirmed in advance, and the value is stored in the memory 4. The value at this time is “temperature fluctuation value # 2”. The CPU 1 sends a signal B to the activation circuit 5 when the storage in the memory 4 is completed. The activation circuit 5 that has received the signal B stops the power supply to the crystal oscillator 8.

  On the other hand, when the radio base station apparatus according to one embodiment of the present invention is in operation, the CPU 1 obtains the temperature in the own apparatus obtained from the temperature sensor 2 and the “reference value # 1” and “temperature fluctuation” stored in the memory 3. The control voltage to be applied to the temperature compensated crystal oscillator 6 is calculated using “value # 1” and sent to the D / A converter 7. The D / A converter 7 generates a DC voltage with the data from the CPU 1 and applies the voltage to the temperature compensated crystal oscillator 6. As a result, a clock signal including a desired frequency component is supplied from the temperature compensated crystal oscillator 6 into the device itself.

  At the start of operation, the CPU 1 sends a signal C to the activation circuit 5 informing that the own device has started operation. Upon receipt of this signal C, the timer circuit 51 in the starter circuit 5 functions, and power is not supplied to the crystal oscillator 8 until an arbitrarily set time T elapses. Here, the arbitrary time T to be set is a time during which the frequency stability standard can be guaranteed by the secular change of the temperature compensated crystal oscillator 6. For example, if the frequency stability of the temperature compensated crystal oscillator 6 can guarantee 0.1 ppm for up to 5 years, the set time T in the starting circuit 5 is 5 years.

  When the timer circuit 51 in the activation circuit 5 measures an arbitrary time T, the power is supplied to the crystal oscillator 8 and the CPU 1 is also notified as a signal D that the power supply to the crystal oscillator 8 is started. The crystal oscillator 8 is turned on for the first time after the start of operation, and the crystal oscillator 8 is not subject to secular change.

  When the CPU 1 receives the signal D, it waits for the activation time t of the crystal oscillator 8. The crystal oscillator 8 can perform a stable operation by the activation time t. During this time, the CPU 1 applies control to the crystal oscillator 8 using the temperature in the own device obtained from the temperature sensor 2 and the “reference value # 2” and “temperature variation value # 2” stored in the memory 4. The voltage is calculated and sent to the D / A converter 9. The D / A converter 9 generates a DC voltage based on the data from the CPU 1 and applies the voltage to the crystal oscillator 8. As a result, a clock signal including a desired frequency component is supplied from the crystal oscillator 8 to the CPU 1.

  After the start-up time t has elapsed, the CPU 1 compares the phase of the output signal of the temperature compensated crystal oscillator 6 with the output signal of the crystal oscillator 8 as a reference. An “adjustment value” of the frequency is calculated from the comparison result, the “adjustment value”, the temperature from the temperature sensor 2, the “reference value # 1” and the “temperature fluctuation value # 1” stored in the memory 3. Thus, the frequency adjustment for the temperature compensated crystal oscillator 6 is actually calculated.

  The CPU 1 sends the calculation result to the D / A converter 7 and applies a control voltage to the temperature compensated crystal oscillator 6, thereby adjusting the frequency fluctuation due to the secular change of the temperature compensated crystal oscillator 6. The CPU 1 compares the phases of the temperature compensated crystal oscillator 6 and the crystal oscillator 8 and sends a signal B to the starter circuit 5 assuming that the adjustment of the frequency fluctuation is completed when the phases match. When the starting circuit 5 receives the signal B, it stops supplying power to the crystal oscillator 8 and stops its function so that the crystal oscillator 8 does not fluctuate in frequency due to aging.

  In addition, when the radio base station apparatus according to the embodiment of the present invention is in operation, in the CPU 1, the data generation unit 11 obtains the temperature in the own apparatus obtained from the temperature sensor 2 and the “reference” stored in the memory 3. The control voltage to be applied to the temperature compensated crystal oscillator 6 is calculated using the value # 1 and the temperature variation value # 1.

  An example of this calculation method is shown below. The “reference value # 1” uses the above-described example, and the “temperature fluctuation value # 1” uses the value shown in FIG. First, the data generation unit 11 combines the temperature of “reference value # 1” = 30 ° C. and the temperature of “temperature fluctuation value # 1” = 30 ° C. to create “temperature adjustment value # 1” (see FIG. 6). ).

  Next, the data generation unit 11 reads the current temperature of the temperature sensor 2. When the temperature = 40 ° C., the data generation unit 11 reads the control voltage value when the temperature = 40 ° C. from “temperature adjustment value # 1”. In this case, it is set to “1.3 V” from the example shown in FIG. The data generator 11 converts this control voltage value (referred to as “control voltage value A”) into the data format of the D / A converter 7 in order to output it from the D / A converter 7.

  The data generation unit 11 sends the converted data to the switching unit 12 as signal # 1. Since the switching unit 12 is switched to send the signal # 1 from the data generation unit 11 to the D / A converter 7 during operation of the own device, the signal # 1 is sent to the D / A converter 7. Become.

  First, when the power of the own device is turned on, the starter circuit 5 does not supply power to the crystal oscillator 8 from the power control circuit 52. Therefore, the CPU 1 sends a signal A to the timer circuit 51 in preparation for operation of the own device. When the timer circuit 51 receives the signal A, the timer circuit 51 immediately sends a signal A ′ for starting the power supply control circuit 52 and starts supplying power to the crystal oscillator 8.

  When the preparation before the operation of the own device is completed, the CPU 1 sends a signal B to the timer circuit 51. When the timer circuit 51 receives the signal B, it sends a function stop signal B ′ to the power supply control circuit 52. In response to this, the power supply control circuit 52 stops the supply of power to the crystal oscillator 8.

  At the start of operation, the CPU 1 sends a signal C to the timer circuit 51 informing that the own device has started operation. When the timer circuit 51 receives the signal C, the timer circuit 51 starts calculating the time. An arbitrary time T can be set in the timer circuit 51, and no control is performed from the timer circuit 51 to the power supply control circuit 52 until the time T elapses.

  When an arbitrary time T elapses, the timer circuit 51 sends a signal C ′ for starting the power supply control circuit 52. In response to this, the power supply control circuit 52 is activated to start supplying power to the crystal oscillator 8. At the same time, the power control circuit 52 notifies the CPU 1 that the power supply to the crystal oscillator 8 is started as a signal D. Thereafter, the CPU 1 starts frequency adjustment of the temperature compensated crystal oscillator 6 and sends a signal B to the timer circuit 51 when the adjustment is completed. When the timer circuit 51 receives the signal B, it sends a function stop signal B ′ to the power supply control circuit 52. In response to this, the power supply control circuit 52 stops the supply of power to the crystal oscillator 8.

  Next, when the crystal oscillator 8 is activated, the data generation unit 21 obtains the temperature in the device obtained from the temperature sensor 2 and the “reference value # 2” and “temperature variation value # 2” stored in the memory 4. Is used to calculate a control voltage to be applied to the crystal oscillator 8. Since the calculation method is the same as that of the data generation part 11, the description is abbreviate | omitted. The data generation unit 21 converts the calculated value “temperature adjustment value 2” into the data format of the D / A converter 9 and sends it to the D / A converter 9.

  When frequency adjustment is performed, the frequency adjustment unit 13 inputs the output signal of the temperature compensated crystal oscillator 6 and the output signal of the crystal oscillator 8 to the comparison unit 131. The comparison unit 131 performs phase comparison between the two signals using the signal from the crystal oscillator 8 as a reference. In order to adjust the phase fluctuation (referred to as “phase fluctuation value” and converted in units of Hz) of the temperature compensated crystal oscillator 6 at this time, the comparison unit 131 uses the “phase fluctuation value” as an adjustment value calculation unit. Send to 132.

  The adjustment value calculation unit 132 stores in advance a modulation sensitivity value (generally expressed in units of Hz / V) that represents the relationship between the control voltage and oscillation frequency of the temperature compensated crystal oscillator 6. . The adjustment value calculation unit 132 calculates a control voltage value “control voltage adjustment value” for adjusting the temperature compensated crystal oscillator 6 from the stored modulation sensitivity value and the “phase fluctuation value” to obtain data. The data is sent to the generation unit 133.

  The data generation unit 133 receives the signal # 1 currently calculated by the data generation unit 11 and sent to the D / A converter 7. At this time, the data generation unit 133 converts the control voltage value described in the signal # 1 into a linear function (y = ax) having a certain coefficient a from the “control voltage value A” and the “control voltage adjustment value”. To do. Here, x is time, and y is a control voltage value output from the D / A converter 7. The time immediately before the frequency adjustment is x = 0, and the control voltage value at this time is y = “control voltage value A”. When x = S after a certain period of time S, a linear function (y = ax) is created with y = “control voltage adjustment value” (see FIG. 7).

  When the switch 12 switches from the signal # 1 of the data generator 11 to the signal # 2 of the data generator 133, the control voltage for the temperature compensated crystal oscillator 6 changes abruptly and is output from the temperature compensated crystal oscillator 6. Since the oscillation frequency of the clock signal to be abruptly changes, there is a concern of affecting the operation of the device itself. Therefore, there is a need to gradually switch over in a slow time that does not affect the operation of the device itself. This is realized by time S and a coefficient a of a linear function (y = ax).

  Therefore, when the data generation unit 133 can create the linear function (y = ax), the signal y is sent to the switch 12, and the switch 12 switches the path so that the signal y is sent to the D / A converter 7. The signal y gradually changes the signal y from “control voltage value A” to “control voltage adjustment value” according to a linear function (y = ax), when the data generation unit 303 starts transmission. When the signal y reaches the “control voltage adjustment value”, the comparator 131 again performs the phase comparison between the temperature compensated crystal oscillator 6 and the crystal oscillator 8, and the process is performed with the “phase fluctuation value” set to “0”. Continue until When “phase fluctuation value” = 0, the frequency adjustment is finished.

  As described above, in this embodiment, since the crystal oscillator 8 is provided in addition to the temperature compensated crystal oscillator 6, the temperature compensated crystal oscillator 6 used in the apparatus itself with the crystal oscillator 8 as a reference. Frequency adjustment can be performed.

  Further, in this embodiment, since the activation circuit 5 for supplying power to the crystal oscillator 8 is provided, the crystal oscillator 8 can be activated at an arbitrarily set time, and the frequency can be automatically adjusted. .

  Furthermore, in this embodiment, the crystal oscillator 8 can be activated at an arbitrary time by the activation circuit 5, so that the crystal oscillator 8 can be prevented from being deteriorated in frequency stability due to secular change.

  Furthermore, in this embodiment, by calculating a linear function when adjusting the frequency, the oscillation frequency of the temperature-compensated crystal oscillator 6 does not fluctuate abruptly, and the operation of the device itself in operation is affected. The frequency can be adjusted without any change.

  FIG. 8 is a block diagram showing the configuration of a radio base station apparatus for mobile communication according to another embodiment of the present invention. In FIG. 8, the basic configuration of a radio base station apparatus according to another embodiment of the present invention is that a temperature compensated crystal oscillator 32 is provided in place of the crystal oscillator 8, and an activation circuit 31 and a switching circuit 33 are added. Except for the further adjustment of the frequency adjustment, the configuration is the same as that of the radio base station apparatus according to the embodiment of the present invention shown in FIG. 1, and the same components are denoted by the same reference numerals.

  By using the same temperature-compensated crystal oscillator 32 as that of the temperature-compensated crystal oscillator 6, it becomes possible to use a reference signal having a higher frequency stability than the above-described embodiment of the present invention. The switching circuit 33 switches between a clock signal output from the temperature compensated crystal oscillator 6 and a clock signal output from the temperature compensated crystal oscillator 32. The start circuit 31 supplies power to and stops the temperature compensated crystal oscillator 6.

  Next, the operation of the radio base station apparatus according to another embodiment of the present invention will be described. The clock signal output from the temperature-compensated crystal oscillator 6 is not supplied directly to the device itself but is supplied via the switching circuit 33. Further, the clock signal output from the temperature compensated crystal oscillator 32 is also supplied into the apparatus via the switching circuit 33.

  Further, the startup circuit 31 supplies power to the temperature-compensated crystal oscillator 6 and continues to supply power until a signal is received from the CPU 1. When a signal is received from the CPU 1, the power supply is stopped. At the start of operation, as described in the above-described embodiment of the present invention, the CPU 1 sends a signal C informing the start of operation of the own device to the activation circuit 5. In response to this signal C, the timer circuit 51 in the starter circuit 5 functions, and power is not supplied to the temperature compensated crystal oscillator 32 until an arbitrarily set time T elapses. Here, the arbitrary time T to be set is a time during which the frequency stability standard can be guaranteed by the secular change of the temperature compensated crystal oscillator 6.

  When the timer circuit 51 detects the elapse of an arbitrary time T, the starter circuit 5 supplies power to the temperature compensated crystal oscillator 32 and signals that the power supply to the temperature compensated crystal oscillator 32 to the CPU 1 has started. Notify as. The temperature compensated crystal oscillator 32 is turned on for the first time after the start of operation, and the temperature compensated crystal oscillator 32 is not subject to secular change.

  When the CPU 1 receives the signal D, it waits for the activation time t of the temperature compensated crystal oscillator 32. The temperature-compensated crystal oscillator 32 can perform a stable operation according to the startup time t. After the activation time t has elapsed, the CPU 1 sends a signal E to the switching circuit 33. When the switching circuit 33 receives the signal E, the switching circuit 33 performs path switching so that the clock signal output from the temperature compensated crystal oscillator 32 is supplied into the device itself.

  After the switching, if the CPU 1 determines that there is no problem in the operation within the device itself, the temperature compensation crystal oscillator 6 of the temperature compensation crystal oscillator 6 is based on the signal from the temperature compensation crystal oscillator 32 in the same manner as in the embodiment of the present invention. The frequency is adjusted, and then the signal F is sent to the starting circuit 31. Upon receiving the signal F, the start circuit 31 stops the power supply of the temperature compensated crystal oscillator 6 and stops the function of the temperature compensated crystal oscillator 6.

  Thus, in this embodiment, before the frequency stability of the temperature compensated crystal oscillator 6 deviates from the standard, the temperature compensated crystal oscillator 32 which is another oscillator is operated to switch the signal generation source of the clock signal. Therefore, in addition to the effect of the embodiment of the present invention described above, the output from the temperature compensated crystal oscillator 32 can be supplied to the own apparatus while the frequency of the temperature compensated crystal oscillator 6 is adjusted. The effect that the influence time by the frequency fluctuation | variation by the secular change of the type | mold crystal oscillator 6 can be shortened is acquired. Note that after the frequency adjustment of the temperature compensated crystal oscillator 6 is performed, the output may be switched to the output of the temperature compensated crystal oscillator 6, or the output of the temperature compensated crystal oscillator 32 may be supplied as it is.

It is a block diagram which shows the structure of the radio base station apparatus for mobile communication by one Example of this invention. It is a block diagram which shows the structure of CPU of FIG. FIG. 2 is a block diagram illustrating a configuration of a startup circuit in FIG. 1. FIG. 3 is a block diagram illustrating a configuration of a portion of the CPU of FIG. 1 that is not illustrated in FIG. 2. It is a block diagram which shows the structure of the frequency adjustment part of FIG. It is a figure which shows the relationship between the detection value of the temperature sensor of FIG. 1, and temperature adjustment with respect to the temperature compensation type | mold crystal oscillator by one Example of this invention. It is a figure for demonstrating the data generation by the data generation part of FIG. It is a block diagram which shows the structure of the radio base station apparatus for mobile communications by the other Example of this invention. It is a block diagram which shows the structure of the radio base station apparatus for mobile communications by a prior art example.

Explanation of symbols

1 CPU
2 Temperature sensor 3, 4 Memory
5 Start-up circuit 6,32 Temperature compensated crystal oscillator 7,9 D / A converter
8 Crystal Oscillator 11, 21 Data Generation Unit 12 Switching Unit 13 Frequency Adjustment Unit 51 Timer Circuit 52 Power Supply Control Circuit 131 Comparison Unit 132 Adjustment Value Calculation Unit 133 Data Generation Unit

Claims (12)

  A radio base station apparatus that uses an oscillator whose oscillation frequency fluctuates with time, timer means for detecting the passage of a preset arbitrary time, and activation when the timer means detects the arbitrary time A radio base station apparatus comprising: a second oscillator configured to adjust the secular change of the oscillator based on a signal oscillated from the second oscillator.   2. The radio base station apparatus according to claim 1, wherein the arbitrary time is a time estimated in advance from characteristics of the oscillator and a frequency variation due to the secular change exceeds an allowable value.   The radio base station apparatus according to claim 1 or 2, wherein the means for adjusting the secular change of the oscillator calculates a linear function when the frequency adjustment is performed.   4. The radio base station apparatus according to claim 1, wherein power is supplied to the second oscillator only while adjusting the secular change of the oscillator. 5. The oscillator is a temperature compensated crystal oscillator,
The radio base station apparatus according to claim 1, wherein the second oscillator is a crystal oscillator. The oscillator and the second oscillator are temperature compensated crystal oscillators,
The radio base station apparatus according to any one of claims 1 to 4, further comprising means for switching between a signal oscillated from the oscillator and a signal oscillated from the second oscillator.   A frequency adjustment method used for a radio base station apparatus that uses an oscillator whose oscillation frequency fluctuates over time, wherein the radio base station apparatus detects a predetermined arbitrary time, and the arbitrary A frequency adjustment comprising: starting a second oscillator when a predetermined time is detected; and adjusting a secular change of the oscillator based on a signal oscillated from the second oscillator. Method.   8. The frequency adjusting method according to claim 7, wherein the arbitrary time is a time estimated in advance from characteristics of the oscillator and a frequency fluctuation due to the secular change exceeds an allowable value.   9. The frequency adjustment method according to claim 7, wherein the process of adjusting the secular change of the oscillator calculates a linear function when the frequency adjustment is performed.   The frequency adjustment method according to any one of claims 7 to 9, wherein power is supplied to the second oscillator only while adjusting the secular change of the oscillator.   11. The frequency adjustment method according to claim 7, wherein the oscillator is a temperature compensated crystal oscillator, and the second oscillator is a crystal oscillator. The oscillator and the second oscillator are temperature compensated crystal oscillators;
The frequency according to any one of claims 7 to 10, wherein the radio base station apparatus executes a process of switching between a signal oscillated from the oscillator and a signal oscillated from the second oscillator. Adjustment method.

Images