JPH0732498B2 - Phase control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used for a mobile radio apparatus for transmitting digital signals using a mobile radio line. In particular, it relates to phase control of a radio signal transmitted by a radio base station.

[Conventional technology]

In a mobile radio device, when digital signals are simultaneously transmitted from a plurality of base stations, in order for the mobile device to receive the signals without error, it is necessary for each radio base station to transmit signals in phase with each other. For this reason, conventionally, (1) a reference signal is transmitted from the central control station to each radio base station, and control is performed so that the phase difference between this reference signal and the signal returned from each radio base station becomes constant. Method, (2) In each wireless base station, compare the phase of the signal coming from the wired line with the phase of the signal passing through the wireless section,
(3) At each radio base station, compare the phase of the signal of the reference station arriving through the radio line with the phase of the signal of its own station through the radio section, and make the phase difference. A method such as a method for controlling so that is constant is used. The method (3) is particularly suitable when the signal speed is high.

[Problems to be solved by the invention]

In order to match the phase difference with high accuracy, it is essential to receive the signal in the wireless section. For this purpose, it is necessary to receive the signal of the reference station with sufficient strength through the wireless section. If the signal-to-noise ratio is low, the phase comparison accuracy deteriorates, and in the worst case, the phase difference cannot be measured. was there.

An object of the present invention is to solve the above problems and to provide a phase control method capable of matching the phases of signals transmitted between radio base stations that cannot directly obtain a sufficient reception electric field. .

[Means for solving problems]

According to the phase control method of the present invention, a phase monitoring station is provided in a common area where the radio areas of both the reference station and the controlled station overlap, and the phase monitoring station receives the radio signals transmitted by the reference station and the controlled station, respectively. Means, means for measuring the time difference between the reference signal received from the controlled station and the phase correction signal received from the reference station, and controlled by obtaining the phase difference between the reference station and the controlled station from the measured time difference Means for notifying the station, and the controlled station includes means for correcting the phase of the radio signal transmitted by the own station according to the notification from the means for notifying.

[Work]

A phase monitoring station is installed at a point where both the reference station and the controlled station can receive radio signals, and the time difference between the phase correction signal and the reference signal, for example, the frame synchronization signal transmitted in each unique time slot is measured. , And sends a control signal to the controlled station according to the measurement result.

Furthermore, the clock of the reference station can be transmitted to the controlled station by transmitting the control signal at the timing of the clock signal reproduced by the received signal from the reference station.

〔Example〕

FIG. 1 is a block diagram showing the phase control method of the embodiment of the present invention.

In order to control the phase of the radio signal transmitted by the controlled station 2 based on the phase of the radio signal transmitted from the reference station 1, the phase monitoring station 3 is provided at a location distant from the reference station 1 and the controlled station 2.

In the place where the controlled station 2 is installed, the electric field strength of the radio signal transmitted by the reference station 1 is insufficient and the signal cannot be received. Between the reference station 1 and the controlled station 2, there is an area where the radio areas of these radio base stations overlap, that is, a common area. In the common area, the ringing rate may decrease due to the phase shift. The phase monitoring station 3 is installed in this common area.

FIG. 2 shows a time chart of phase control.

The reference station and the controlled station transmit frame signals at the same timing, and, for example, at the start of every other frame signal,
The reference signal and the phase correction signal are alternately transmitted. The phase monitoring station measures the time difference between the reference signal from the controlled station and the phase correction signal from the reference station, and controls the timing of the next reference signal transmission by the measured station.

FIG. 3 is a block diagram showing a first example of the phase monitoring station 3.

This phase monitoring station measures the time difference between the radio signal receiving unit 37 that receives radio signals transmitted by the reference station and the controlled station, and the reference signal received from the controlled station and the phase correction signal received from the reference station. Means, that is, the high-speed clock generator 31, the gate circuit 32, and the counter 33, and means for controlling the controlled station so that the measured value of this means is constant, that is, the delay amount controller 34, the encoder 35, and the modulator.
And a decoding unit 38 for decoding the received signal of the wireless signal receiving unit 37.

The phase monitoring station further includes a clock regenerator 40 that regenerates a clock signal from the signal received from the reference station, and a gate circuit 39 that supplies a received signal to the clock regenerator 40. Further, this phase monitoring station uses the delay amount control section 34, the encoding section 35 and the modulation section 36 as means for supplying the regenerated clock signal to the controlled station via a cable.

The operation of this phase monitoring station will be described.

The decoding unit 38 decodes the signal received by the wireless signal receiving unit 37. When receiving the reference signal transmitted from the controlled station, for example, the frame synchronization signal, the gate circuit 32 is opened. As a result, the output of the high speed clock generator 31 is supplied to the counter 33. The high-speed clock generator 31 generates a high-speed clock having a frequency higher than that of the transmission signal, for example, a frequency several hundred times higher than that of the transmission signal. The counter 33 counts this high speed clock.

Next, the decoding unit 38 receives the phase correction signal from the reference station. When this signal is received, the decoding unit 38 closes the gate circuit 32 and ends the counting operation of the counter 33.
The delay amount control unit 34 obtains the phase difference between the phase of the signal transmitted by the reference station and the signal when the controlled station transmits by the count value of the counter 33, and outputs the delay amount control signal. Encoding unit 35
Encodes this delay amount control signal, and the modulator 36 sends the encoded signal to the controlled station via a wired line.

Upon receiving the delay control signal, the controlled station corrects the phase at the timing of phase correction of its own station.

Further, the decoding unit 38 opens the gate circuit 39 at the timing when the controlled station is not transmitting a signal and supplies the signal from the reference station to the clock reproducing unit 40. The clock recovery unit 40 starts the synchronization pull-in and synchronizes the clock generated by itself with the reference signal. Further, the decoding unit 38 closes the gate circuit 39 at the timing when the controlled station restarts transmission. As a result, the clock reproduction unit 40 is in the free-running state.

The clock signal output from the clock reproduction unit 40 is supplied to the delay amount control unit 34, and the delay amount control unit 34 sends a control signal at the timing of this clock signal. The encoding unit 35 and the modulation unit 36 also operate according to this clock signal. When there is no control signal, the clock signal is sent as it is.

FIG. 4 is a block diagram showing a second example of the phase monitoring station 3 and a part of the controlled station 2.

This phase monitoring station 3 differs from the first embodiment in that a human reads the count value of the counter 33 and manually inputs the control amount to be sent to the controlled station 2.

That is, the phase monitoring station 3 includes a manual input unit 301 that can manually input the phase delay amount of the controlled station 2, and a delay amount setting unit 3 that sets the delay amount by the input from the manual input unit 301.
02 and the phase monitor station 3 by modulating the output of the delay amount setting unit 302.
And a modulation unit 303 for sending to the.

The controlled station 2 includes a demodulation unit 22 that demodulates the control signal from the phase monitoring station 3, and a switching unit 23 that supplies one output of the demodulation unit 22 or the delay amount setting unit 21 to the encoding unit 35. The delay amount setting unit 21 outputs a control signal for automatically performing the phase compensation operation. The switching unit 23 selects this signal when a control signal is input from the phase monitoring station 3. As a result, the delay amount can be set by interrupting the automatic phase compensation operation.

〔The invention's effect〕

As described above, according to the phase control method of the present invention, the phase monitoring station is installed at a point where two radio signals of the reference station and the controlled station can be received, and the phase monitoring station transmits the reference station and the controlled station. The phase of the controlled station is controlled remotely by measuring the phase difference between the signals. As a result, there is an effect that the phase can be accurately controlled even if the controlled station is arranged in a weak electric field area where the radio wave of the reference station does not reach. That is, by arranging the controlled station in the weak electric field area in this way, it is possible to prevent a reduction in the ringing rate caused by the phase shift due to the overlapping of the wireless areas.

[Brief description of drawings]

FIG. 1 is a block diagram showing a phase control method according to an embodiment of the present invention. FIG. 2 is a diagram showing a time chart of phase control. FIG. 3 is a block diagram showing a first example of the phase monitoring station. FIG. 4 is a block diagram showing a second example of the phase monitoring station and a part of the controlled station. 1 ... Reference station, 2 ... Controlled station, 3 ... Phase monitoring station, 21
...... Delay amount setting section, 22 ...... Demodulation section, 23 ...... Switching section, 31 ...
… High-speed clock generator, 32,39 …… Gate circuit, 33 ……
Counter, 34 ... Delay amount control unit, 35 ... Encoding unit, 36,
303 ... Modulation section, 37 ... Radio receiving section, 38 ... Decoding section, 40 ... Clock recovery section, 301 ... Manual input section, 302 ...
... Delay amount setting section.

Claims (1)

[Claims] 1. A phase control method for controlling the phase of a radio signal transmitted by a controlled station based on the phase of a radio signal transmitted from a reference station, wherein a common wireless area in which both the reference station and the controlled station overlap each other. A phase monitoring station is provided in the area, and the phase monitoring station receives the radio signals transmitted by the reference station and the controlled station, the reference signal received from the controlled station and the phase received from the reference station. Means for measuring a time difference from the correction signal, and means for notifying the controlled station of the phase difference between the reference station and the controlled station from the measured time difference, and notifying the controlled station. Includes a means for correcting the phase of a radio signal transmitted by the local station according to the notification from the notification means.