JPS5963829A - Method for comparing electric field between base stations - Google Patents

Abstract

PURPOSE:To remove a tone signal removing filter from a wire circuit between base stations by comparing received electric field intensity of each base station by using a tone signal generated from the base station in accordance with the received electric field intensity, and when the received electric field of the self- station is low, stopping the tone signal generated from the self-station. CONSTITUTION:In a radio communication system between a base station and a mobile station, the base station 3 controls a tone oscillator 3e by the received electric field of a receiver 3j to generate a tone signal corresponding to the electric field intensity and sends the tone signal to another base station through wire circuits 5b, 6a. A tone detector 3f detects the received electric field intensity of the other base station from the tone signal generated from the other base station and a comparator 3 compares the detected intensity with the received electric field intensity of the self-station. When the received electric field intensity of the self-station is lower, the operation of the tone oscillator 3c is stopped, and when larger, a switch 3k is closed and the output of the receiver 3j is sent to the wire circuit 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a wireless communication system between a base station and a mobile station. In particular, the present invention relates to a method suitable for a car telephone system, and a comparison of received electric field strength at each base station in a wireless communication system having a plurality of base stations connected by wired lines as base stations.

[Description of prior art]

Conventionally, the base station for wireless communications in this building had the configuration shown in Figure 1. In its configuration, each fixed base station 2, 3, 4, etc. is connected to a mobile station 1, which is freely movable, through wired lines 5a, 5b, 6a, 6b. The wired line 5d, whose transmission direction is from the base station 2 to the base station 3, is input to the tone detector 3f that detects 1-tone corresponding to the strength of the received electric field, and also removes the tone from the base station 2. Connected to the input of filter 3a.

In addition, a wired line 6b inputting from the base station 4 to the base station 3 is connected to the above-mentioned ]-tone detector 3f, and is also connected to the synthesis amplifier 3d via a filter 3b for removing the 1-tone coming from the base station 4. to use human power. The output side of the synthetic amplifier 3d is connected to the base station 2 via a wired line 6a. The output side of the filter 3a is inputted to a delay time drinker 3h, and is also inputted to the base station 4 via a wired line 5b via another synthesis amplifier 3c. Further, the transmitting and receiving antenna of the base station 3 is connected to a transmitter 31 and a receiver 3j, and one output of the receiver 3j is coupled to the input side of a 1-tone oscillator 3e.
Furthermore, along with the output of the tone detector 3f, the electric field comparator 3g
and the other output terminal of the receiver 3j is connected to a switch 3 whose on/off control is controlled by the output of the comparator 3g.
k to the combining amplifier 3d.

Further, the output of the delay equalizer 3h is connected to a transmitter 31. Note that the output of the tone oscillator 3e is coupled to a synthesis amplifier 3c and also to a synthesis amplifier 3d.

To explain the operation of this conventional example, when receiving at a base station, for example, in the base station 3, a tone oscillator 3e is controlled by the received electric field of the receiver 3j, and the tone oscillator 3e is used as a signal corresponding to the strength of the received electric field. generate a tone. The tones are sent by synthesis amplifiers 3C and 3d to base station 4 and base station 2, respectively, via wire lines 5b and 6a. Further, a tone corresponding to the received electric field of the base station 2 is sent from the wired line 5a, and a tone corresponding to the received electric field of the base station 4 is sent from the wired line 6b. Tone detector 3f
Based on the transmitted tone, the strength of the received electric field of the other base station is determined. Comparator 3g compares this with the received electric field of your own station.
When the received electric field of the own base station is stronger than that of other base stations, the switch 3k is turned on. At this time, the received output of the receiver 3j is sent from the synthetic amplifier 3d to the wired line 6a.

When the received electric field of another base station is stronger than that of the own base station, switch 3k is turned off. As a result, only the reception output of the base station with the strongest electric field is connected (the active line/＼connection), and the S/N (signal text/I noise a) of the line is ensured.

The purpose of the filter 3b is to remove tones from other base stations. The base station transmits all bases (transmits from its own station) so that the mobile station 1 can receive it at any location. Since the reception distortion at the mobile station 1 becomes large, the amount of delay is corrected by the heavy equipment 3h (delay, etc.). At this time, the tone of the own station is sent to the In addition, if 1 is added, the level of 1.- will become excessive and the S/N power will increase by 1, so the filter 3a will remove the tones of other bases. 4) Same! She is my daughter.

In this way, the delay of each base station's wireless network is strongly added to the delay of the wired line, so delays, etc.
The amount of delay to be corrected also increases. In addition, it becomes difficult to create a filter (which requires a filter with flat η phase characteristics and whose characteristics are 1I) as a filter. - In addition, since adjacent base stations 1 - - are removed by taro filtering, base 1 that is two or more stations apart (L comparison between 1 stations is not possible, and there are multiple stations with strong electric fields, Tsu111iJI
4 When there is a station with a weak electric field, multiple stations connect to the wired line 1j1.
In order to apply four received outputs, the level J was increased, resulting in large deviations and distortions.

- [Object of the Invention] The present invention solves the above-mentioned drawbacks, and aims to provide a system in which the tone added from the tone oscillator to the wired line can be controlled by the tone signal from base stations over a wide range of areas. In order to
It is an object of the present invention to provide an inter-base station comparison method that makes it possible to perform electric field comparison over a wide range with less phase distortion by correcting delay amounts only for easy wired lines.

[Summary of the Invention] - The present invention provides a method for transmitting a 1-tone signal for comparison of received electric fields between base stations and a (1) signal for communication purposes in a plurality of base stations connected in cascade via a wired line. When transmitting on the same wired line by frequency division, etc., it was determined from the signal indicating the received electric field of another base station (when the received electric field of the own base station is stronger than the received electric field of the color base station (G1) and when the received electric field of the other base station is When a tone signal indicating the received electric field is not sent, a tone signal indicating the electric field is sent out, and if the base station's own base station is weaker, it is not sent, and only the signal of the station with the strongest received electric field is sent to the wired line. It is characterized by being configured so that

[Explanation based on examples]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of an embodiment of the present invention.

Compared to the conventional example shown in FIG. 1, the comparator 3g is provided with another output line and connected to the tone oscillator 3e, and the output of the comparator 3g controls the on/off of the tone oscillator 3e. In this way, a tone signal is generated only when the receiving electric field of the own station is larger than the receiving electric field of the other station. As a result, wired lines 5a, 5bs 6a
The tones flowing to s and 6b are only the tones emitted by the base station with the maximum received electric field.

The filter 3a connected in series to the wired lines 5a and 5b in FIG. 1 is removed (short-circuited), and another filter 3a' is delayed.
tangent in series with. Further, the filter corresponding to filter 3b in FIG. 1 is unnecessary in the present invention and is not used. The names and functions of the constituent parts in FIG. 2 other than those mentioned above are exactly the same as those explained in the conventional example of FIG. 1.

As a result of the above, the number of times that the signal to the transmitter of each base station passes through the filter 3a' is only once for each base station.

That is, the delay equalizer 3h in series with it is the wired line 5a,
Since only the small delay amount of 5b needs to be corrected, it becomes simple and adjustment becomes easy. Further, even if the phase characteristic of the filter 3a' is not flat, it can be easily created as long as there is little difference between the filters of each base station. In addition, since the 1--tone of the line is sent to all base stations without being removed by a filter as in the conventional case, it is easy to compare the electric fields even between base stations that are two or more apart. .

〔Effect of the invention〕

According to the present invention, as explained above, it is possible to send signals sent from other stations, which are the purpose of communication, to other base stations without passing through a filter, including tone signals. Instead of a complicated filter with good phase characteristics,
This can be done using a cheap and simple filter. According to the present invention, it is possible to obtain an electric field comparison method that is stable and allows comparison of °ζ electric fields between base stations over a wide range.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional system. FIG. 2 is a block diagram showing an embodiment of the present invention. 1... Mobile station, 2.3.4... Base station. Patent applicant: NEC Corporation.

Claims (1)

[Claims] (1) A receiver, a transmitter, and a tone oscillator that generates a tone signal corresponding to the receiver and transmits it to an adjacent base station are installed inside multiple base stations connected by wired lines for signal transmission. and an I-on signal that detects an I-on signal transmitted from an adjacent base station.
a comparator that compares the received electric field of the adjacent base station and the received electric field of the own station sent to the output of the 1.-n detector, and a wired line that transmits the signal to the adjacent base station. and the bone (g
In the inter-base station electric field comparison method, the switch is connected to the output of the comparator and is controlled to open and close by the output of the comparator. An electric field comparison method between base stations, characterized in that the I-on oscillator is configured to operate only when the received electric field of the own station is larger than the received electric field of an adjacent base station.