JP3338812B2 - Mobile communication base station device and automatic impedance matching method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to matching between the load impedance and the output impedance of the driver or the input impedance of the receiver even when the load impedance seen from the driver changes due to the increase or decrease of the number of receivers on the transmission line. The present invention relates to a mobile communication base station apparatus that automatically performs impedance matching by automatically selecting a terminating resistor, and an automatic impedance matching method thereof.

[0002]

2. Description of the Related Art When dealing with a signal for removing noise entering a transmission line or performing high-speed switching, it is necessary to deal with a distributed constant. In a distributed constant circuit that handles a distributed constant, the voltage and current on the transmission line are determined by the resistance, capacitance, inductance, and conductance per unit length of the transmission line. The characteristic impedance of the transmission line is the above-mentioned ratio of voltage and current.

[0003]

However, depending on the level of the overshoot or undershoot on the transmission line and the transition time, data stored in a register in the electronic circuit may be destroyed.

If a stepped waveform occurs at the threshold level of the receiver, data cannot be captured during that time.

In order to solve such a problem, it is necessary to provide a terminating resistor for matching the impedance between the load impedance on the transmission line and the output impedance of the driver or the input impedance of the receiver. Also, since the load impedance seen from the driver side differs depending on the number of receivers, a plurality of terminating resistors used for impedance matching are required.

In this case, when a high-speed driver is used to output a signal, the transmission line is long and requires matching by a terminating resistor, and when it becomes necessary to take a signal from any point on the transmission line, impedance matching is performed. It is necessary to provide a plurality of terminating resistors at both ends of the transmission line.

Further, even when the load impedance seen from the driver changes due to an increase or decrease in the number of receivers, a terminating resistor that matches the load impedance with the output impedance of the driver or the input impedance of the receiver is automatically selected. Therefore, a technique that can perform impedance matching is required.

The present invention has been made in view of such circumstances, and even when the load impedance seen from the driver changes due to an increase or decrease in the number of receivers, the load impedance and the output impedance of the driver or the input impedance of the receiver are not changed. It is possible to provide a mobile communication base station apparatus capable of automatically performing impedance matching by automatically selecting a terminating resistor that matches between the two, and a method for automatically performing impedance matching.

[0009]

According to a first aspect of the present invention, there is provided a mobile communication base station apparatus, which is a wireless transceiver, wherein a plurality of transmission / reception cards, the number of which is increased or decreased according to the size of a subscriber capacity, and an apparatus. It has functions of monitoring, controlling, and storing information on the system, generating data for the device and generating various clocks, and mounting the plurality of transmission / reception cards.
A signal output card including a control card having a function of transmitting unmounted monitoring data, and a terminating resistor for a change in characteristic impedance of a transmission line viewed from the signal output card due to a change in the number of mounted transmission / reception cards. used with a automatic impedance matching circuit for performing impedance matching with an automatic and a termination resistance adjusting circuit for adjusting the termination resistor by terminating resistors change data transmitted from the automatic impedance matching circuit, the automatic impedance matching times
The path comprises the characteristic impedance of the transmission line and the signal output.
Output impedance of power card or input of transmitting / receiving card
Different values for matching with impedance
A plurality of terminating resistors for which
・ Receiving unmounted monitoring data and receiving the plurality of transmission / reception cards
Calculate the number of mounted boards and send out the result data of the number of mounted boards
Circuit for calculating the number of mounted cards
Select one of the terminating resistors according to the
Selector for connecting a path and the selected terminating resistor
And characterized in that: Further, the terminating resistance adjusting circuit may include a plurality of terminating resistors corresponding to the terminating resistors on the impedance automatic matching circuit side, and any one of the terminating resistors on the terminating resistance adjusting circuit side according to the mounting number calculation result data. And a data selector for connecting the transmission line and the selected terminating resistor. The automatic impedance matching circuit includes a pulse generation circuit that generates a pulse for detecting a change in the characteristic impedance of the transmission line viewed from the automatic impedance matching circuit, and a reflected wave that is generated when the impedance is mismatched. And a reflected wave detection circuit for detecting. Further, the termination resistance adjusting circuit may include a buffer for detecting a pulse from the pulse generating circuit when the impedance is matched. 6. The automatic impedance matching method for a mobile communication base station device according to claim 5, wherein the first step is to increase / decrease the number of transmission / reception cards, which are wireless transceivers, according to the subscriber capacity. A signal output card that includes monitoring and controlling the inside of the device, storing information on the system, generating data for the inside of the device and generating various clocks, and sending mounted / unmounted monitoring data of the plurality of transmission / reception cards. In the second step, with respect to a change in the characteristic impedance of the transmission line as viewed from the signal output card accompanying a change in the number of mounted transmission / reception cards, impedance matching is automatically performed using a terminating resistor by an impedance automatic matching circuit. A third step to be performed;
The termination resistance adjusting circuit, and a fourth step of adjusting the termination resistance using the terminal resistance change data transmitted from the automatic impedance matching circuit, the third step
Is the characteristic impedance of the transmission line and the signal output
The output impedance of the card or the input
Different values for matching with impedance
A fifth method of providing a plurality of terminating resistors having set resistance values
Process and the mounting card count calculation circuit
Receiving the monitoring data, and mounting the plurality of transmitting / receiving cards
The sixth is to calculate the number of sheets and send out the result data of the number of mounted sheets.
Process and the data selector,
Selecting one of the terminating resistors according to visual data,
A seventh step for connecting the transmission line and the selected terminating resistor.
And a step is included . In the fourth step, an eighth step of providing a plurality of terminating resistors corresponding to the terminating resistors on the automatic impedance matching circuit side, A ninth step of selecting any one of the terminal resistors on the terminal resistor adjustment circuit side and connecting the transmission line and the selected terminal resistor may be included. The third step includes a step of generating a pulse for detecting a change in the characteristic impedance of the transmission line as viewed from the automatic impedance matching circuit by a pulse generation circuit; And an eleventh step of detecting a reflected wave generated at that time by a reflected wave detection circuit. Further, the fourth step may include a twelfth step of detecting a pulse from the pulse generation circuit by a buffer at the time of matching of the impedance. In the mobile communication base station apparatus and the impedance automatic matching method according to the present invention, a signal output card including a control card is provided by increasing or decreasing the number of transmission / reception cards, which are radio transceivers, according to the subscriber capacity. In addition to monitoring information in the device, controlling and storing information on the system, generating various clocks for data transmission in the device and transmitting monitoring data for mounting / unmounting of a plurality of transmission / reception cards, The automatic impedance matching circuit automatically adjusts the impedance using the terminating resistor in response to the change in the characteristic impedance of the transmission line as seen from the signal output card due to the change in the number of mounted ICs. Adjust the termination resistance using the termination resistance change data sent from the circuit. That.

[0010]

Embodiments of the present invention will be described below.

(First Embodiment) FIG. 1 is a diagram showing a model of a transmission line according to a first embodiment of the mobile communication base station apparatus of the present invention, and FIGS. 2 and 3 are FIGS. FIG. 4 is a diagram showing a reflected wave time transition in the transmission line of FIG. 4, and FIG.
FIG. 5 is a diagram showing a terminal configuration of a base station that monitors and controls mobile communication on the transmission line in FIG. 1. FIG. 6 is a mobile communication that monitors and controls mobile communication on the transmission line in FIG. 1. FIG. 7 is a diagram showing a base station apparatus, FIG. 7 is a diagram showing a configuration of an automatic impedance matching circuit of FIG. 6, FIG. 8 is a diagram showing a configuration of a termination resistance adjusting circuit of FIG. 6, and FIG. Flowchart for explaining the operation of the communication base station apparatus, FIG.
0 is a view showing a detection register of the mounted / unmounted state of the transmission / reception card of FIG. 6, and FIG. 11 is a view showing a terminating resistor selected by the number of transmission / reception cards and mounted cards of FIG.

Before describing the mobile communication base station apparatus of the present invention, a concept relating to the mobile communication base station apparatus of the present invention will be described with reference to FIGS.

In the transmission line shown in FIG. 1, between the transmission end (driver) a and the point A of the transmission line c, the transmission line c
And a traveling signal are generated between the point B and the receiving end (receiver) b.

This is because when a transmission end (driver) a for outputting a signal and a reception end (receiver) b for receiving the signal are connected via the transmission line c, the transmission line c If there is a mismatch between the characteristic impedance and the output impedance of the transmitting end (driver) a or the input impedance of the receiving end (receiver) b, the connection between point A, which is a connection point having different impedance, and the transmitting end (driver) a. This is because a signal that returns between the point B and the receiving end (receiver) b and a traveling signal are generated.

Here, the reflected wave, which is a signal that is returned, is
This will be described with reference to FIG. First, the output impedance of the transmitting end (driver) a is ZR, the input impedance of the receiving end (receiver) b is ZB, and the characteristic impedance of the transmission line c is Z0.

The reflection coefficient at the connection point B between the receiving end (receiver) b and the transmission line c is ρ1 = (ZB-Z0) / (ZB + Z
0), the reflection coefficient at the connection point A between the transmission end (driver) a and the transmission line c can be expressed as ρ2 = (ZR−Z0) / (ZR + Z0). Further, when an output signal to V _i, to the connection point A of the transmitting end (driver) a transmission line c V = V
A voltage of i × ZR / (ZR + Z0) appears.

Referring to FIG. 2, the magnitude of the reflected wave changes with the lapse of time τ during which the signal travels through the transmission line c shown in FIG. 1. Therefore, as shown in FIG. A signal including a stepped waveform generated when the line c is long and the round trip time of the reflected wave is long is output from the transmission end (driver) a to the transmission line c, the transmission line c
At the input point to the receiving end (receiver) b.

Next, referring to FIG. 4, when a plurality of receiving ends (receivers) b-1 are driven from a transmitting end (driver) a, a branch point is a transmission line c viewed from the transmitting end (driver) a. It is considered that the impedance on the side, that is, the load impedance has changed to １ ／.

However, since the characteristic impedance itself of the transmission line c does not change due to the increase or decrease in the number of the receiving ends (receivers) b-1, the number of the driven receiving ends (receivers) b-1 is one. Then, impedance matching between the characteristic impedance of the transmission line c and the output impedance of the transmitting end (driver) a or the input impedance of the receiving end (receiver) b-1 may be performed.

When there are a plurality of receiving ends (receivers) b-1, since the load impedance seen from the transmitting end (driver) a differs depending on the number of receiving ends (receivers) b-1, new impedance matching is performed. This must be performed, and if the impedance matching is not performed, the noise margin is impaired by multiple reflection.

Further, when dealing with noise entering the transmission line c or a signal for performing high-speed switching, it is necessary to handle the signal like a distributed constant. In a distributed constant circuit,
The voltage and current on the transmission line c are determined by the resistance, capacitance, inductance, and conductance per unit length of the transmission line. The characteristic impedance of the transmission line c is the above-mentioned ratio of voltage and current.

Depending on the level of the overshoot and undershoot and the transition time, the data stored in the register in the electronic circuit may be destroyed. If the stepped waveform occurs at the threshold level of the receiver, the data during that time may be lost. You will not be able to capture. To solve this problem, load impedance and transmitting end (driver) a
It is necessary to provide a terminating resistor for impedance matching with the output impedance of the receiver or the input impedance of the receiving end (receiver) b. Further, since the load impedance seen from the transmitting end (driver) a differs depending on the number of receiving ends (receivers) b-1, a plurality of terminating resistors used for impedance matching are required.

Therefore, when a high-speed transmitting end (driver) a is used for signal output, the transmission line c is long and requires matching by a terminating resistor, and it is necessary to take a signal from any point of the transmission line c, That is, since each card mounted on the device is a device configured to input and output signals,
In order to perform impedance matching, it is necessary to provide terminating resistors d at both ends of the transmission line c as shown in FIG.

This impedance matching is performed by using an automatic impedance matching circuit. Receiving end (receiver) b-
Even if the load impedance seen from the transmitting end (driver) a changes due to the increase or decrease of the number of 1, the output impedance of the transmitting end (driver) a or the input impedance of the receiving end (receiver) b is matched. Termination resistors d and e can be automatically selected.

Next, a mobile communication base station apparatus for monitoring and controlling mobile communication according to the present invention will be described.

The mobile communication base station device 9 shown in FIG. 6 includes an automatic impedance matching circuit 1, a terminal resistance adjusting circuit 2, a control card 3, a clock card 4, and a transmission / reception card (1) 5 connected on a transmission line 8. To (40) 7. Here, the control card 3 and the clock card 4 are also signal output cards.

The automatic impedance matching circuit 1 has a characteristic impedance of the transmission line 8 as viewed from an arbitrary signal output card (control card 3 and clock card 4) due to a change in the number of mounted transmission / reception cards (1) 5 to (40) 7. , The impedance is automatically matched using a terminating resistor. The details will be described later.

The termination resistance adjusting circuit 2 adjusts the termination resistance according to the termination resistance change data transmitted from the automatic impedance matching circuit 1. The control card 3 monitors the inside of the device,
It has a function of controlling and storing information on the system. The clock card 4 has a function for transmitting data within the device and generating various clocks.

The transmission / reception cards (1) 5 to (40) 7 are radio transceivers. In addition, these transmission / reception cards (1)
In (5) to (40) 7, the number of mounted cards increases or decreases depending on the subscriber capacity of the mobile communication system.

Further, in this embodiment, the total number of mounted transmission / reception cards (1) 5 to (40) 7 is 40, but it is not always necessary to be 40. Also, all cards mounted on the device perform input and output of signals.

Next, details of the automatic impedance matching circuit 1 are shown in FIG.

The automatic impedance matching circuit 1 includes a mounted card number calculation circuit 11, a data selector 12, and terminating resistors (1) 13 to (4) 16.

The mounted card number calculation circuit 11 receives the mounted / unmounted monitoring data of the transmission / reception cards (1) 5 to (40) 7 from the control card 3 in FIG. 6 (8-bit data), and receives the transmission / reception card (1). 5 to (40) 7 are calculated. Further, the mounted card number calculation circuit 11 transmits the data on the number of mounted cards of the transmission / reception cards (1) 5 to (40) 7 to the data selector 12 (2-bit data).

The data selector 12 selects one of the terminating resistors (1) 13 to (4) 16 according to the received data, and selects the transmission line 8 and the selected terminating resistor (1) 13 to
(4) Connect to 16. Terminating resistor (1) 13-(4)
16 can match the characteristic impedance of the transmission line 8 with the output impedance of the signal output card or the input impedance of the signal reception card even when the load impedance seen from the signal output card fluctuates due to the increase or decrease in the number of mounted transmission / reception cards. The resistance value is set.

Next, details of the termination resistance adjusting circuit 2 are shown in FIG.

The termination resistance adjusting circuit 2 includes a data selector 2
1 and terminating resistors (1) 22 to (4) 25.

The data selector 21 receives data (2 bits) from the mounted card number calculation circuit 11 in the automatic impedance matching circuit 1. Data selector 21
The terminating resistors (1) 22 to 22 are obtained from the number-of-mounted-sheets calculation result data from the number-of-mounted-cards calculating circuit 11 similarly to the data selector 12 in the automatic impedance matching circuit 1 in FIG.
(4) Any one of 25 is selected, and the transmission line 8 is connected to the selected terminating resistors (1) 22 to (4) 25.

The terminating resistors (1) 22 to (4) 25 include terminating resistors (1) in the automatic impedance matching circuit 1.
Similarly to 13 to (4) 16, even when the load impedance seen from the signal output card fluctuates due to an increase or decrease in the number of mounted transmission / reception cards, the characteristic impedance and the output impedance of the signal output card or the transmission / reception card (1) 5
(40) 7 are set to different resistance values that can match the input impedance.

As described above, the automatic impedance adjusting circuit 1 and the terminating resistor matching circuit 2 use the terminating resistors (1) 13 to (4) 16, (1) 22-
(4) Match using 25.

Next, the operation of the mobile communication base station apparatus 9 having such a configuration will be described.

First, the transmitting / receiving cards (1) 5 to (40) 7 are attached to the mobile communication base station device 9 shown in FIG.
Mount. Next, as shown in FIG. 9, the power is turned on (step 901), and the operation in that state is checked.

After the power is turned on, the data selector 12 in the automatic impedance matching circuit 1 shown in FIG. 7 selects the terminating resistor (1) 13 by initial setting (step 9).
02). Similarly, the data selector 21 in the termination resistance adjustment circuit 2 shown in FIG. 8 selects the termination resistance (1) 22.

The selected terminating resistors (1) 13 and (1)
Reference numeral 22 denotes a transmission line 8 in which all the transmission / reception cards (1) 5 to (40) 7 are mounted (20), and a signal output card (control card 3 and clock card 4) or transmission / reception card (1) 5 To (40) 7.

That is, each of the terminating resistors (1) 13 to (4)
16, (1) 22 to (4) 25 include the number of mounted transmission / reception cards (1) 5 to (40) 7, 10, 20, 30,
A resistance value for matching impedance between the transmission line 8 and the signal output card or the transmission / reception card (1) 5 to (40) 7 when the number is 40 is set.

Next, the control card 3 constantly transmits a status report request signal to all the transmitting and receiving cards (1) 5 to (40) 7. Each of the transmission / reception cards (1) 5 to (40) 7 having received the status report request signal transmits a monitoring response and status report data to the control card 3. After transmitting the status report request signal, the control card 3 determines that the transmission / reception cards (1) 5 to (40) 7, which have no status report data within a predetermined time, are not mounted (step 903).

From the status report result, the transmission / reception card (1)
It is possible to confirm the mounted / unmounted state of 5 to (40) 7. Next, the control card 3 is mounted on the transmission / reception card shown in FIG.
'1' is added to all registers of 0000h to 0001h of the unmounted state register and D0 to D3 of 0002h, and
'0' is written to D4 to D7 and 0003h to 0004h of 2h, and transmitted to the mounted card number calculation circuit 11 of the automatic impedance matching circuit 1 (step 904).

The transmission / reception card mounted / unmounted state data is always transmitted to the mounted card number calculation circuit 11. As a result, the number of mounted transmission / reception cards (1) 5 to (40) 7 can always be confirmed, and the transmission line 8 and the signal output card or transmission / reception card (1) are increased or decreased according to the number of mounted cards.
It is possible to always prevent the impedance mismatch between 5 and (40) 7.

The mounted card number calculating circuit 11 which has received the confirmation data calculates the number of mounted transmitting and receiving cards. As shown in FIG. 10, the number of mounted transmission / reception cards is calculated by detecting mounted bits at addresses 0000h to 0004h and adding the detection results to the currently mounted transmission / reception cards (1) to (40). 7 is calculated.

The mounting card number calculation circuit 11 is provided with a mounting bit
Since 20 “1” s have been detected, S1 = “H” S0 = “L” is transmitted to the data selector 12 and the data selector 21 in the termination resistance adjusting circuit 2 as shown in FIG. The data selector 12 and the data selector 21 in the termination resistance adjustment circuit 2 determine the termination resistance (2) 14 from the 2-bit data transmitted from the mounted card number calculation circuit 11 and the data in the termination resistance adjustment circuit 2. The selector 21 selects the terminating resistors (2) 23 and connects them to the transmission line 8 (steps 905 and 906).

Even after the connection with the terminating resistors (2) 14 and (2) 23, the control card 3 always monitors the data on the mounted / unmounted transmission / reception card. However, the terminating resistors (1) 13 to (4) 1
6, (1) 22 to (4) 25 can be automatically varied. Thereby, the load impedance and the output impedance of the signal output card or the transmission / reception cards (1) 5 to (4)
0) It is possible to prevent the occurrence of overshoot, undershoot, and stepped waveform of the signal due to the mismatch between the input impedances 7).

As described above, in the first embodiment, the number of mounted transmission / reception cards (1) 5- (40) 7, which are radio transceivers, is increased or decreased according to the subscriber capacity.
The signal output card including the control card 3 stores information on monitoring, control and system in the device, generates data for data transmission in the device and generates various clocks, and further includes a plurality of transmission / reception cards (1) 5 to (40). 7) Transmits the mounted / unmounted monitoring data of 7, and transmits and receives a plurality of transmission / reception cards (1) 5 to
(40) Automatic impedance matching using a terminating resistor is automatically performed by the automatic impedance matching circuit 1 in response to a change in the characteristic impedance of the transmission line as viewed from the signal output card due to the change in the number of mounted components, and a terminating resistor adjusting circuit is provided. 2, the terminating resistors (1) 13 to 13 using the terminating resistor change data transmitted from the automatic impedance matching circuit 1
(4) Since 16 and (1) 22 to (4) 25 are adjusted, even if the load impedance seen from the driver changes due to an increase or decrease in the number of receivers, the load impedance and the output impedance of the driver or the input of the receiver are changed. It is possible to automatically select a terminating resistor that matches with the impedance, and to automatically perform impedance matching.

As a result, the occurrence of overshoot, undershoot and stepped waveform due to impedance mismatch can be prevented.

(Second Embodiment) FIG. 12 is a diagram showing a second embodiment in which the configuration of the automatic impedance matching circuit of FIG. 7 is changed, and FIG. 13 is a termination resistance adjusting circuit of FIG. And FIG. 14 is a diagram showing a transmission pulse propagation model.

The automatic impedance matching circuit 100 shown in FIG.
2. Data selector 103 and terminating resistor (1) 104-
(4) 107 is provided. Here, the pulse generation circuit 1
Reference numeral 01 denotes a pulse for detecting a change in the characteristic impedance of the transmission line 800 as viewed from the automatic impedance matching circuit 100. Reflected wave detection circuit 10
2 detects a reflected wave generated at the time of impedance mismatching.

The termination resistance adjusting circuit 200 shown in FIG.
A data selector 202, a buffer 203, and terminating resistors (1) 204 to (4) 207 are provided. Here, the buffer 203 is provided for reflection confirmation.

Next, the operation will be described.

First, the distance of the transmission line 800 is long, the propagation delay time is longer than the rise or fall time of the signal pulse, and the load impedance and the output impedance of the signal output card or the transmission / reception card (1) shown in FIG.
When there is a mismatch between the input impedances 5 to (40) 7, reflection occurs.

The second embodiment is characterized by utilizing the reflected wave. That is, the pulse generation circuit 101 and the reflected wave detection circuit 102 are provided at the farthest end from the transmission line 800 in the automatic impedance matching circuit 100.

By providing the pulse generation circuit 101 and the reflected wave detection circuit 102 at the farthest end, the return time of the reflected wave generated at the connection point between the transmission line 800 and the automatic impedance matching circuit 100 can be extended, and the reflected wave can be increased. Can be detected.

One pulse whose rise and fall of the signal pulse is shorter than the propagation delay time of the transmission line 800 and shorter than the time of reciprocation of the transmission line 800 from the pulse generation circuit 101 is a buffer of the termination resistance adjusting circuit 200 shown in FIG. 2
03 is sent.

This buffer 203 is for reflection confirmation,
The output of this buffer 203 is open. If the transmitted pulse does not match the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100, the transmitted pulse is reflected back to the transmitting end.

When the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 are matched, no reflection occurs, and only the original pulse of the transmitted pulse is detected by the reflected wave detection circuit 102. .

Referring to FIG. 14, pulse generation circuit 10
When the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 are mismatched, one pulse transmitted from 1 is reflected by the reflected wave detection circuit 102 as an original transmission pulse and a pulse folded by reflection. Is detected.

When two or more pulses are detected, the reflected wave detection circuit 102 determines that the characteristic impedance is mismatched. When the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 are mismatched, the reflected wave detection circuit 102 adds the terminating resistance (1) to the data selector 103 and the data selector 202 in the terminating resistance adjusting circuit 200. 104 to (4) 107
(1) Transmit control data for changing 204 to (4) 207.

The data selector 103 and the data selector 202 in the termination resistance adjustment circuit 200 determine the termination resistance (2) 105 based on the data received from the reflected wave detection circuit 102 and the data selector in the termination resistance adjustment circuit 200. 202 selects the terminating resistor (2) 205 respectively. After selecting the terminal resistance (2) 105, the pulse generation circuit 101 transmits one pulse to the buffer 203 of the terminal resistance adjustment circuit 200 again.

Here, again, the reflected wave detection circuit 102
When one or more pulses are detected, control data for selecting the terminating resistors (3) 106 and (3) 206 is transmitted to the data selector 103 and the data selector 202 in the terminating resistor adjusting circuit 200. Thus, the characteristic impedance of the transmission line 800 and the impedance automatic matching circuit 10
A series of operations is repeated until the output impedance of 0 is matched.

Further, even after the matching between the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 has been performed, the pulse generation circuit 101 always transmits a pulse. For this reason, the characteristic impedance of the transmission line 800 as viewed from the automatic impedance matching circuit 100 changes, and the characteristic impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 become mismatched due to an increase or decrease in the number of mounted transmission / reception cards. In this case, the terminating resistor (1) 104-
(4) Selection of 107 (1) and 204 to (4) 207 is performed.

The pulse generation circuit 101 transmits a pulse to the transmission line 800 at a specific cycle. The period is a time τ when the pulse generation circuit 101 transmits one pulse to the transmission line 800 and reaches the reception end, a time τ when the pulse turns from the reception end to the transmission end, and a control data from the reflected wave detection circuit 102. Is transmitted and the time β during which the data selector 103 and the terminating resistance adjusting circuit 200 change the terminating resistance is set to (2τ + β).

In the reflected wave detection circuit 101, this cycle is set to the cycle for detecting the reflected wave, and the detection data is cleared in this cycle. Accordingly, when the impedance of the transmission line 800 and the output impedance of the automatic impedance matching circuit 100 are matched, the reflected wave detection circuit 102 does not detect two or more pulses during one cycle.

As described above, in the second embodiment, the transmission line 800 viewed from the automatic impedance matching circuit 100
A pulse for detecting a change in the characteristic impedance of the input signal is generated by the pulse generation circuit 101, a reflected wave generated at the time of impedance mismatch is detected by the reflected wave detection circuit 102, and the impedance of the impedance is detected by the termination resistance adjustment circuit 200. Pulse generation circuit 10 during matching
By detecting the pulse from 1 by the buffer 203, even if the load impedance seen from the driver changes due to an increase or decrease in the number of receivers, a terminating resistor matching between the load impedance and the output impedance of the driver or the input impedance of the receiver. (1) 104-
(4) Selection of 107 (1) and 204 to (4) 207 can be performed automatically, and impedance matching can be performed automatically.

As a result, the occurrence of overshoot, undershoot and stepped waveform due to impedance mismatch can be prevented.

[0072]

As described above, according to the mobile communication base station apparatus and the automatic impedance matching method thereof according to the present invention,
The number of mounted transmission / reception cards, which are wireless transceivers, is increased or decreased according to the size of the subscriber capacity. A signal output card including a control card is used to store information on monitoring, control and system in the device, and to store information on the system. Generates various clocks for internal data transmission and sends out monitoring data for mounting / unmounting of multiple transmission / reception cards, and changes in the characteristic impedance of the transmission line as seen from the signal output card due to the change in the number of mounted multiple transmission / reception cards In contrast, the automatic impedance matching circuit automatically matches the impedance using the terminating resistor, and the terminating resistor adjusting circuit adjusts the terminating resistor using the terminating resistance change data transmitted from the automatic impedance matching circuit. Change in the load impedance as seen by the driver due to an increase or decrease in the number of receivers. But, between the input impedance of the output impedance or receiver of the load impedance and the driver can be automatically performed selection of the terminating resistor for matching can perform impedance matching automatically.

[Brief description of the drawings]

FIG. 1 is a diagram showing a model of a transmission line according to a first embodiment of a mobile communication base station apparatus of the present invention.

FIG. 2 is a diagram showing a reflected wave time transition in the transmission line of FIG. 1;

FIG. 3 is a diagram showing a reflected wave time transition in the transmission line of FIG. 1;

FIG. 4 is a diagram illustrating a multiple reflection model based on a branch pattern in the transmission line of FIG. 1;

FIG. 5 is a diagram illustrating a terminal configuration of a mobile communication base station apparatus that monitors and controls mobile communication on the transmission line of FIG. 1;

FIG. 6 is a diagram illustrating a mobile communication base station apparatus that monitors and controls mobile communication on the transmission line of FIG. 1;

FIG. 7 is a diagram showing a configuration of the automatic impedance matching circuit of FIG. 6;

FIG. 8 is a diagram showing a configuration of a termination resistance adjusting circuit of FIG. 6;

FIG. 9 is a flowchart for explaining the operation of the mobile communication base station apparatus of FIG. 6;

FIG. 10 is a diagram showing a detection register for mounting / non-mounting of the transmission / reception card of FIG. 6;

11 is a diagram showing a terminating resistor selected according to the number of transmission / reception cards and mounted cards in FIG. 6;

FIG. 12 is a diagram showing a second embodiment in which the configuration of the automatic impedance matching circuit of FIG. 7 is changed.

FIG. 13 is a diagram showing a case where the configuration of the termination resistance adjusting circuit of FIG. 8 is changed.

FIG. 14 is a diagram showing a transmission pulse propagation model.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Impedance automatic matching circuit 2 Termination resistance adjustment circuit 3 Control card 4 Clock card 5-7 Transmission / reception card (1)-(40) 8 Transmission line 9 Mobile communication base station apparatus 11 Number of mounted cards calculation circuit 12 Data selector 13-16 Terminating resistors (1) to (4) 21 Data selector 22 to 25 Terminating resistors (1) to (4) 100 Impedance automatic matching circuit 101 Pulse generation circuit 102 Reflected wave detection circuit 103 Data selector 104 to 107 Terminating resistor (1) to (4) 200 termination resistance adjustment circuit 202 data selector 203 buffer 204 to 207 termination resistance (1) to (4) 800 transmission line

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 102 H04Q ^7/ 00-7/38

Claims (8)

(57) [Claims] 1. A wireless transceiver having a plurality of transmission / reception cards whose number to be mounted is increased or decreased according to the size of a subscriber capacity, a function of monitoring and controlling the inside of the device and storing information on a system, A signal output card including a control card having a function of generating data for transmitting data in the device and generating various clocks and transmitting monitoring data for mounting / unmounting of the plurality of transmission / reception cards, and a change in the number of mounted plurality of transmission / reception cards. An automatic impedance matching circuit that automatically performs impedance matching using a terminating resistor with respect to a change in the characteristic impedance of the transmission line as viewed from the signal output card, and is terminated by terminating resistance change data transmitted from the automatic impedance matching circuit. and a termination resistance adjusting circuit for adjusting the resistance, the automatic impedance matching circuit of the transmission line Characteristic impedance and the signal output car
Output impedance of the
A plurality of terminating resistors different resistance values of the respective values for performing matching with the-impedance has been set, the actual
Receiving the monitoring data of mounted / unmounted
Calculates the number of mounted boards and sends out the result data of the number of mounted boards
Circuit for calculating the number of mounted cards to be mounted, and the number of termination resistors according to the mounted / unmounted monitoring data.
And selecting the transmission line and the selected terminating resistor.
And a data selector for connecting the mobile communication base station. 2. The termination resistance adjustment circuit according to claim 2, wherein: a plurality of termination resistances corresponding to the termination resistance on the impedance automatic matching circuit side; and the termination resistance on the termination resistance adjustment circuit side based on the mounting number calculation result data. The mobile communication base station apparatus according to claim 1 , further comprising: a data selector that selects one of the transmission lines and connects the transmission line and the selected termination resistor. 3. The automatic impedance matching circuit includes: a pulse generating circuit that generates a pulse for detecting a change in a characteristic impedance of the transmission line viewed from the automatic impedance matching circuit; The mobile communication base station apparatus according to claim 1, further comprising: a reflected wave detection circuit that detects a reflected wave. 4. The circuit according to claim 1, wherein the terminating resistance adjusting circuit includes a buffer for detecting a pulse from the pulse generating circuit when the impedance is matched.
The mobile communication base station device according to claim 1 . 5. A first step of increasing / decreasing the number of transmitter / receiver cards, which are wireless transceivers, according to the subscriber capacity, and a signal output card including a control card for monitoring, controlling and controlling the inside of the apparatus. A second step of storing information on the system and generating various clocks for in-apparatus data transmission and various kinds of clocks, and transmitting mounted / unmounted monitoring data of the plurality of transmission / reception cards; A third step of automatically performing impedance matching using a terminating resistor by an impedance automatic matching circuit with respect to a change in the characteristic impedance of the transmission line as viewed from the signal output card due to the change; and a fourth step of adjusting the termination resistance using the terminating resistor changes data to be transmitted from the automatic impedance matching circuit, the third In the step, the characteristic impedance of the transmission line and the signal output
Output impedance of the
Resistors with different values for matching with
Fifth step of providing a plurality of terminating resistors for which values are set
And the mounted card count calculation circuit
Data and calculate the number of mounted
6th step of sending out and sending out the number-of-mounted-sheets calculation result data
And data selector, to the mounted / unmounted monitoring data
Select one of the terminating resistors according to the transmission line and
It includes a seventh step of connecting the termination resistor in the selected
An automatic impedance matching method for a mobile communication base station apparatus. 6. An eighth step of providing a plurality of terminating resistors corresponding to the terminating resistors on the side of the automatic impedance matching circuit in the fourth step; claims wherein the selected one of the terminating resistors of the adjusting circuit side the terminating resistor, characterized in that it includes a ninth step of connecting the termination resistors and the transmission line and the selection is used
6. The automatic impedance matching method for a mobile communication base station device according to 5 . 7. A third step in which a pulse generating circuit generates a pulse for detecting a change in the characteristic impedance of the transmission line viewed from the automatic impedance matching circuit; The method according to claim 5 , further comprising an eleventh step of detecting a reflected wave generated at the time of mismatching by a reflected wave detection circuit. 8. The moving body according to claim 5 , wherein the fourth step includes a twelfth step of detecting a pulse from the pulse generation circuit with a buffer when the impedance is matched. An automatic impedance matching method for a communication base station device.