JP3631716B2 - W-CDMA radio base station and delay time difference correction method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a W-CDMA radio base station for automatically correcting a delay time deviation of each transmitter having a transmission diversity configuration and a delay time difference correcting method thereof.
[0002]
[Prior art]
A conventional technique will be described with reference to FIG. In a transmission diversity W-CDMA radio base station (hereinafter referred to as BTS), a measuring instrument such as a transmitter tester or a high-frequency oscilloscope is connected to the BTS output terminal 5 and the BTS output terminal 15 to measure delay time deviation. . Based on the measured delay time deviation, the delay adjustment circuits 2 and 12 are controlled to adjust the delay time.
[0003]
In addition, in the Japanese Patent Application 2000-368785, the present applicant detects a delay time deviation based on an SCH (Synchronization Channel) signal by a TSTD (Time Switched Transmit Diversity) circuit and adjusts the delay time. Is disclosed.
[0004]
[Problems to be solved by the invention]
However, in the conventional delay time adjustment method, it is necessary to prepare an expensive measuring instrument when adjusting the delay time deviation, and the measurement time and labor cost of the delay time are required.
[0005]
The conventional WCDMA radio base station is premised on using an SCH signal based on the TSTD scheme.
[0006]
Therefore, an object of the present invention is to provide a W-CDMA radio base station that automatically corrects delay time deviations of transmitters having a transmission diversity configuration with a simple configuration and a delay time difference correction method thereof.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, in the present invention, in FIG. 1, the BB (abbreviation of Base Band) input signal (Sig1, Sig11), which is transmission data in the idle circuits 1 and 11, is transmitted in the non-transmission state (BB signal). Are all 0), and each transmission carrier is distributed by the directional couplers 4 and 14 before the BTS output terminals 5 and 15 and detected by the detectors 6 and 16. The control circuit 20 detects a time deviation between the detected falling edge of the 0-system idle period and the detected falling edge of the 1-system idle period. If the 0 system falling edge is faster in the detected time deviation between the 0 system and the 1 system, the 0 system transmitter 100 is delayed by delaying the time by the time deviation advanced in the 0 system delay adjustment circuit 2. A time deviation from the transmitter 110 of the first system is eliminated. When the 1 system falling edge is faster than the detected time difference between the 0 system and the 1 system, the time corresponding to the time deviation advanced by the 1 system delay adjustment circuit 12 is delayed to delay the 0 system transmitters 100 and 1. It is characterized by eliminating the time deviation from the transmitter 110 of the system.
[0008]
With the above configuration, the delay time deviation between the 0-system transmitter 100 and the 1-system transmitter 110 is eliminated.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0010]
Referring to FIG. 1, a portion constituted by an idle circuit 1, a delay adjustment circuit 2, an RF circuit 3, a directional coupler 4, and a BTS output terminal 5 is a 0-system transmitter 100, and the idle circuit 11 and delay adjustment are performed. A portion constituted by the circuit 12, the RF circuit 13, the directional coupler 14, and the BTS output terminal 15 is a 1-system transmitter 110.
[0011]
The 0-system transmitter 100 includes an idle circuit 1 that converts a BB input signal (Sig1), which is transmission data, into all zeros and outputs a 0-system BB transmission signal (Sig2) in order to make a non-transmission state during IPDL, and an idle circuit A delay adjusting circuit 2 for setting a desired delay time of the 0-system transmission signal (Sig2) output from 1 to a desired delay time by the control signal (Sig4), and delaying and outputting the 0-system transmission signal (Sig2); The RF circuit 3 that modulates the carrier wave with the 0-system transmission signal (Sig2) delayed at 2 and amplifies it to a desired power and outputs an RF (radio frequency) signal, and the 0-system that is output from the RF circuit 3 The directional coupler 4 that distributes two RF signals, the BTS output terminal 5 that inputs the 0-system RF signal output from the directional coupler 4 and outputs the RF signal to the antenna 0, and the directional coupler 4 The And a detector 6 which converts the RF signal of the system to the detection to the 0-system BB transmission signal (Sig 3).
[0012]
The 1-system transmitter 110 converts an BB input signal (Sig11), which is transmission data, into all zeros to output a 1-system BB transmission signal (Sig12), and an idle circuit. A delay adjustment circuit 12 for setting a desired transmission delay time of the 1-system transmission signal (Sig12) output from the control signal 11 by a control signal (Sig14) and outputting the 1-system transmission signal (Sig12) by delaying; The RF circuit 13 that modulates the carrier wave with the 1-system transmission signal (Sig12) delayed at 12 and amplifies it to a desired power and outputs an RF (radio frequency) signal, and the 1-system that is output from the RF circuit 13 A directional coupler 14 that distributes two RF signals, and a BTS output terminal 15 that inputs a 1-system RF signal output from the directional coupler 14 and outputs the RF signal to the antenna 10. , And a detector 16 for converting the 1-system BB transmission signal by detecting the RF signal of one system is distributed from the directional coupler 14 (Sig13).
[0013]
The 0-system transmission signal (Sig3) output from the detector 6 of the transmitter 100 and the 1-system transmission signal (Sig13) output from the detector 16 of the transmitter 110 are input, and the delay time deviation is corrected. For this purpose, it further includes a control circuit 20 for outputting the 0-system control signal (Sig4) and the 1-system control signal (Sgi14) to the delay adjustment circuits 2 and 12, respectively.
[0014]
FIG. 2 is a block diagram showing the control circuit 20 in the present invention. The control circuit 20 includes an A / D converter 21 that converts the 0-system analog transmission signal (Sig3) output from the detector 6 into a digital signal, and a 1-system analog transmission signal (Sig13) output from the detector 16. A / D converter 22 for converting the signal into a digital signal, a 0-system digital transmission signal output from A / D converter 21 and a 1-system digital transmission signal output from A / D converter 22 are input and delayed. In order to correct the time deviation, the CPU 23 outputs the 0-system control signal (Sig4) and the 1-system control signal (Sig14) to the delay adjustment circuits 2 and 12, respectively, and is connected to the CPU 23 for delay time deviation control. The memory 24 stores a program in advance.
[0015]
Next, the operation of the above circuit will be described. Note that IPDL temporarily makes transmission from the BTS in a non-transmission state in order to measure the time difference required for the location information service (according to 3GPP specification TS.25.214).
[0016]
The IPDL information is received from a higher-level device such as an RNC (network control device), and the BB input signals (Sig1, Sig11) are set to all zero in the idle circuits 1 and 11 to generate a non-transmission state called an idle period. During normal system operation without IPDL, the idle circuits 1 and 11 output the input BB signals (Sig1, Sig11) as they are. The BB input signals (Sig1, Sig11) are signals obtained by subjecting a signal sent from a higher-level device such as RNC to spreading modulation, error correction coding, framing and the like inside the BTS. The carrier wave (2110 to 2170 MHz) is modulated by the output 0 system transmission signal (Sig2), amplified to a desired power, and output as an RF signal. The output 0-system RF signal is divided into two by the directional coupler 4 and output to the BTS output terminal 5, and the other distributed 0-system RF signal is detected by the detector 6 to be detected by the control circuit 20. Is input. Similarly, the 1-system transmission signal (Sig 12) is also input to the control circuit 20 through the RF circuit 13, the directional coupler 14, and the detector 16. In the control circuit 20, the CPU 23 operates based on a program stored in advance in the memory 24.
[0017]
As shown in FIG. 3, the control circuit 20 detects the delay time deviation based on the falling edges of the 0-system transmission signal (Sig3) and the 1-system transmission signal (Sig13), and corrects the delay time deviation. Therefore, control signals (Sig4, Sig14) are output to the delay adjustment circuits 2 and 12, respectively. The delay adjustment circuits 2 and 12 adjust the delay time based on the control signals (Sig4 and Sig14) output from the control circuit 20. The delay adjustment circuits 2 and 12 can be adjusted with a general shift register circuit.
[0018]
The delay time deviation correction control method will be described with reference to the flowchart of FIG. For example, when the falling edges of the 0-system transmission signal (Sig3) and the 1-system transmission signal (Sig13) are input to the control circuit 20 at the same timing (A = B) (St2), the control circuit 20 It is determined that there is no delay time deviation between the system transmitter 100 and the system 1 transmitter 110 (St12), and the system 0 and system 1 delay adjustment circuits 2 and 12 are controlled to the current delay time (St13). . As a result, there is no delay time deviation between the 0-system transmitter 100 and the 1-system transmitter 110.
[0019]
The falling edge of the 0 system is input to the control circuit 50 ns faster than the falling edge of the 1 system (St2, 3, 4), and the control amounts of the current 0 system and 1 system delay adjusting circuits 2, 12 are In the case of 0 ns (St6), the delay adjustment circuit 2 of the 0 system is controlled to be delayed by 50 ns, and the delay time of the delay adjustment circuit 12 of the 1 system is kept at the current 0 ns (St8). This eliminates the delay time deviation between the 0-system transmitter 100 and the 1-system transmitter 110.
[0020]
The falling edge of the 1st system is input to the control circuit 13 150ns faster than the falling edge of the 0th system (St2, 3, 5), and the current control amount of the delay adjusting circuit 2 of the 0th system is 50ns. When the control amount of the delay adjustment circuit 12 is 0 ns (St7), the delay time of the 0-system delay adjustment circuit 2 is controlled to 0 ns, and the delay time of the 1-system delay adjustment circuit 12 is set to 100 ns (St10). Accordingly, the delay time adjustment is performed for 150 ns, and the delay time deviation between the 0-system transmitter 100 and the 1-system transmitter 110 is eliminated.
[0021]
Since it is an object of the present invention to eliminate delay time deviations of transmission signals output from the 0-system BTS output terminal 5 and the 1-system BTS output terminal 15, the 0-system directional coupler 4 to the BTS output terminal 5 And a transmission line having the same characteristics so that there is no delay time deviation from the directional coupler 14 of the first system to the BTS output terminal 15. Similarly, transmission lines and detectors 6 and 16 having the same characteristics are connected so that there is no delay time deviation from the 0-system directional coupler 4 to the CPU 23 input and from the 1-system directional coupler 14 to the CPU 23 input. .
[0022]
The reason why it is necessary to eliminate the delay time deviation between the 0-system transmission signal (Sig2) and the 1-system transmission signal (Sig12) in transmission diversity is that if there is a time deviation, the effect of transmission diversity is lost (known in the art). Technology). Transmit diversity for the purpose of maintaining high communication quality at all times by selecting and demodulating BTS 0 antenna output and 1 antenna output of a BTS with a high reception level in a fading environment by a mobile communication terminal device such as a cellular phone It is carried out. Nevertheless, if there is a delay time deviation in the received signal input to the mobile communication terminal apparatus, high-quality demodulation cannot be performed if a high-level BTS transmission signal is selected.
[0023]
Next, another embodiment of the present invention will be described. Referring to FIG. 5, when only one carrier is used in a two-carrier diversity radio base station using four transmitters 31, 32, 33, and 34, the delay of four transmitters 31, 32, 33, and 34 is used. When the time deviation is adjusted and each transmitter 31, 32, 33, 34 is set to the same frequency carrier, the combined power is doubled at the output of the combiners 40, 41 than the diversity radio base station with two transmitters. Become. This can expand the cell range.
[0024]
【The invention's effect】
As described above, the first effect of the present invention is that the falling edge where the IPDL is not transmitted is measured by the control circuit, and the rising edge rises faster by the time difference between the measured 0 and 1 falling edges. By delaying the time by an early amount by the delay adjustment circuit of the lowered system, the delay time in each transmitter becomes equal, so that the delay time deviation of the transmission diversity configuration can be adjusted.
[0025]
The second effect is that the delay time deviation of the transmission diversity configuration can be automatically adjusted, so that the delay time deviation does not occur even if the RF circuit fails and is switched to the standby RF circuit.
[0026]
The third effect is that the delay time deviation automatic adjustment system according to the present invention can be created with inexpensive parts, and an expensive measuring instrument for measuring the delay time deviation is not required, and the delay time adjustment is performed periodically. Since no maintenance cost is incurred, the cost can be reduced.
[0027]
The fourth effect is that it can be configured with a circuit originally including a delay time adjustment function, an IPDL function, and an ALC function (Auto Loop Control: automatic transmission power control function). It is possible to contribute to downsizing without requiring a mounting space, and the apparatus cost does not increase.
[Brief description of the drawings]
FIG. 1 is a block diagram of an embodiment according to the present invention. FIG. 2 is a detailed block diagram of a control circuit of FIG. 1. FIG. 3 is a time chart for explaining delay time deviation detection according to the present invention. FIG. 5 is a block diagram of another embodiment according to the invention. FIG. 6 is a block diagram for explaining the prior art.
DESCRIPTION OF SYMBOLS 0,10 Antenna 1,11 Idle circuit 2,12 Delay detection circuit 3,13 RF circuit 4,14 Directional coupler 5,15 BTS output terminal 6,16 Detector 20 Control circuit 21,22 A / D converter 23 CPU
24 Memory 31, 32, 33, 34 Transmitter 35, 36, 37, 38 Detector 39 Control circuit 40, 41 Synthesizer 100, 110 Transmitter

Claims (6)

In a W-CDMA radio base station having a transmission diversity configuration, an idle circuit that outputs a baseband transmission signal with a baseband input signal set to zero in order to make a non-transmission state during IPDL,
A delay adjustment circuit that outputs a baseband transmission signal by delaying the baseband transmission signal output from the idle circuit by a time set by a control signal;
An RF circuit that modulates a carrier wave with a baseband transmission signal delayed by the delay adjustment circuit and outputs an RF signal;
A directional coupler for distributing the RF signal into two parts;
A first transmitter and a second transmitter each having a detector that detects one of the distributed RF signals and converts the detected RF signal into a baseband transmission signal;
The first baseband transmission signal output from the detector of the first transmitter and the second baseband transmission signal output from the detector of the second transmitter are input, and a delay time deviation between them is input. And a control circuit that outputs the control signal for correcting the delay time deviation to the delay adjustment circuits of the first and second transmitters, respectively. Bureau. The control circuit detects a time deviation between a falling edge of the idle period of the first baseband transmission signal and a falling edge of the idle period of the second baseband transmission signal, and calculates a delay time deviation. The W-CDMA radio base station according to claim 1, wherein a control signal for correction is output. The control circuit adjusts the delay of the first transmitter when a time deviation detection result of the first and second baseband transmission signals is earlier than a falling edge of the first baseband transmission signal. Outputs a control signal that delays the time for the time deviation going to the circuit,
When a falling edge of the second baseband transmission signal is earlier, a control signal for delaying a time corresponding to a time deviation going to the delay adjustment circuit of the second transmitter is output. The W-CDMA radio base station according to claim 2. The said 1st and 2nd transmitter is respectively comprised by several transmitters, The output of the transmitter which comprises the said is combined, and it transmits from each diversity antenna, The characterized by the above-mentioned. The W-CDMA radio base station according to any one of the above. A method for correcting a delay time difference in a W-CDMA radio base station having first and second transmitters having a transmission diversity configuration,
In the first and second transmitters, receiving an IPDL signal from a host device and setting a baseband input signal to zero corresponding to an idle period, and outputting a baseband transmission signal;
Modulating the carrier wave with the output baseband transmission signal at the first and second transmitters and outputting an RF signal;
In the first and second transmitters, the RF signal is divided into two, one of them is detected and converted into a baseband transmission signal;
Detecting a delay time deviation between a first baseband transmission signal output from the first transmitter and a second baseband transmission signal output from the second transmitter; Outputting a control signal for correcting the delay time deviation to each of the second transmitters;
Delaying a time baseband transmission signal set by the control signal at the first and second transmitters, and a delay time difference correction method for a W-CDMA radio base station. Control for correcting a delay time deviation by detecting a time deviation between a falling edge of an idle period of the first baseband transmission signal and a falling edge of an idle period of the second baseband transmission signal 6. The delay time difference correction method for a W-CDMA radio base station according to claim 5, wherein a signal is output.

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