JPS6313374B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Description of the technical field to which the invention pertains] The present invention relates to a signal synchronization control method for a wireless communication system in which signals of the same information are simultaneously transmitted from a plurality of base stations at the same frequency.

[Description of prior art]

Generally, when the same signal is simultaneously transmitted from multiple base stations using the same wireless channel, it is necessary to align the phases of the modulated signals to improve the reception rate when receiving in the CO-CHANNEL area where they interfere with each other. .

Conventionally, when transmitting the same signal simultaneously from multiple base stations connected to the central station by an approach line, the signal sent from the central station is transmitted via the approach line after adjusting the phase at each base station. There is.

FIG. 1 shows a system configuration diagram of this conventional system. In other words, central station 1 has approach line 2.
Base stations 3 ₁ to 3 _o are connected by terminals ₁ to 2 _o .
In such a conventional system, first, a signal sent from the central station 1 to the approach line 2 is sent to the base station 3 ₁ ,
It reaches base station 3 _o via base station 3 ₂ , . However, the phases of the signals received at each base station 3 ₁ to 3 _o do not match due to the delay caused by the approach line 2 . For this reason, each base station 3 ₁ to 3 _o is provided with a delay circuit section, and the base station 3 _o with the longest signal phase is provided with a delay circuit section.
By matching this line delay to , the phases of the same signals transmitted from all base stations 3 ₁ to 3 _o are aligned.

However, when the number of signals transmitted simultaneously becomes two or more, this conventional method requires approach lines and delay circuits for phase adjustment in accordance with the number of signals.

[Description of the purpose of the invention]

The present invention improves this point, and when transmitting multiple signals from multiple base stations simultaneously with the same phase, the number of approach lines between base stations is minimally one pair, and furthermore, delay adjustment does not become complicated. The purpose is to provide a signal synchronization control method.

[Summary of the invention]

The present invention is a system in which the same signal is simultaneously transmitted from multiple base stations connected by an approach line using the same radio channel, and a specific pattern is transmitted to each base station from a single phase-adjusted reference signal. circuit means for detecting and generating synchronization pulses;
The present invention is characterized in that it includes circuit means for transmitting other signals generated in independent synchronization based on this synchronization pulse.

[Explanation based on examples]

An embodiment of the present invention will be described based on the drawings.
FIG. 2 is a block diagram of essential parts of a base station according to an embodiment of the present invention. FIG. 2 representatively shows the base station ₃₁ . The approach line 2 ₁ is connected to the line amplification section 5, and the output thereof is guided to the delay correction section 6 and also to the approach line 2 ₂ of the next section.
The output of this delay correction section 6 is guided to a transmitter 12 and also to a pattern detection section 8 . The output of this pattern detection section 8 is guided to a phase synchronization section 9. The output of the tone oscillation section 10 is guided to this phase synchronization section 9. Further, the output of the phase synchronization section 9 is guided to the transmitter 7. Also, 11
indicates an antenna.

A case will be described in which continuous data and tone signals are simultaneously transmitted from a plurality of base stations 3 ₁ to 3 _o connected to the central station 1 by a party line using such a circuit configuration. Now, the data signal sent out from the central station ₁ is input to the line amplification section 5 through the approach line 21, and after level correction due to line loss, is sent out to the delay correction section 6 and the approach line ₂₂ for the terminal side base station. . In the delay correction unit 6, all base stations 3 ₁
The data signals of ~ _3o are adjusted so that their phases match, are modulated and input to the transmitter 7, and are transmitted as radio waves from the antenna 11.

On the other hand, in the case of tone signal transmission, the pattern detection section 8 detects a start pattern included in the data signal, generates a pulse output, and sends it to the phase synchronization section 9. This pulse is detected as a start pulse after the phase of the data signal is matched at all base stations ₃₁ to _3o by the delay correction unit 6, so all base stations ₃₁ to _3o are detected at the same time. will occur. Further, this start pattern is included in the normal data signal, and other specific patterns may be detected instead of being created for this purpose.

In this state, the tone signal independently synchronously oscillated by the tone oscillator 10 is phase-corrected in the phase synchronizer 9 based on the above-mentioned pulses, is modulated and inputted to the transmitter 7, and is modulated into radio waves by the antenna 11 and transmitted. be done. Therefore, the data signals and tone signals sent from each base station 3 ₁ to 3 _o are in phase, and mobile stations located in the CO-CHANNEL interference area can reliably receive these signals.

Further, if a data oscillation section is provided in place of the tone oscillation section 10 shown in the above embodiment, the phase of other data signals can be similarly corrected.

Furthermore, even when transmitting a plurality of signals in addition to the reference data, the same pattern detection section 8 can be shared and the same implementation can be achieved by simply adding a signal oscillation section and a phase synchronization section.

Furthermore, the same method can be applied to a plurality of base stations connected to the central station 1 by approach lines that spread radially.

[Explanation of effects]

As described above, according to the present invention, each base station detects a specific pattern of data signals having the same phase, and uses the detected output to correct the phase of the transmitted signal.

Therefore, even when transmitting multiple signals with the same phase from multiple base stations connected by approach lines, there is no need to add approach lines between base stations, and there is no need to add a circuit for delay adjustment. It has the advantage that there is no need to add more.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a conventional example. FIG. 2 is a block diagram of essential parts of an embodiment of the present invention. DESCRIPTION _OF SYMBOLS 1...Central station, _21-2o ...Approach line, _31-3o ... _Base station, 5...Line amplification section,
6... Delay correction section, 7... Transmitter, 8... Pattern detection section, 9... Phase synchronization section, 10... Tone oscillation section, 11... Antenna.

Claims (1)

[Claims] 1. In a wireless transmission system in which a plurality of base stations are connected to one central station via an approach line and the same signals are simultaneously transmitted from the plurality of base stations on the same radio channel, the base station: A circuit that corrects the phase of the reference signal given from the approach line so that it matches at each base station, a pattern detection section that detects a specific pattern from the output of this circuit, and a pattern detection section that detects a specific pattern from the output of this circuit; A wireless transmission system comprising means for correcting the phase of the output of the pattern detection section and transmitting the signal.