JPH0393326A - Reception antenna system for plural zones - Google Patents

Abstract

PURPOSE:To decrease the number of reception antennas of a base station by devising the system such that each of N sets of reception antennas of the base station receives the radio wave of its own communication zone and a radio wave of adjacent communication zones and one of the radio wave is distributed to the receiver of an adjacent communication zone. CONSTITUTION:A wave received by an antenna 1 is amplified by a low noise amplifier (LN AMP) 1A to compensate the deterioration in the S/N due to level reduction by a succeeding 2-distributer (2 DIV) 1B, and divided into two, a main reception wave and a diversity reception wave for adjacent 6-th sector by the 2DIV-1B. The main reception wave from the 2DIV-1B and a diversity reception wave received by an adjacent 2 antenna are demodulated by reception demodulators 11C, 11D, excellent S/N is selected and the result is connected to each communication channel. The similar operation is implemented in other 2nd-6th sectors. Thus, the number of reception antennas of the base station is decreased.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-zone receiving antenna system in a mobile communication system, and particularly when a base station in a wireless mobile telephone employs a space diversity reception system. The present invention relates to a multi-zone receiving antenna system that reduces the number of base station receiving antennas.

[Conventional technology]

Conventionally, in this type of multi-zone receiving antenna system, for example, as shown in the explanatory diagram of FIG.
The reception is divided into sectors 1 to 6, and for each sector, for example, in the l-th sector, the antenna 27A,
In the same manner as in each sector from 27B onwards, two antennas each, antennas 32A and 32B, are prepared in the sixth sector. Here, one of the antennas 27A and 27B is an antenna for space diversity reception. Therefore, 12 receiving antennas were required in the 6-sector system.

[Problem to be solved by the invention]

In the conventional multi-zone receiving antenna system described above, when the receiving area is divided into, for example, six sectors with the base station at the center, and space diversity reception is performed, 12 receiving antennas are required.

Furthermore, one transmitting antenna is required for each sector, so a total of 18 antennas must be attached to the base station. Therefore, there is a drawback that it is very difficult to secure a place to install the antenna at the base station.

[Means to solve the problem]

In the multi-zone receiving antenna system of the present invention, N (N is an integer) communication zones are arranged around a wireless communication base station, and mobile stations in each communication zone and the base station perform space diversity reception. In a multi-zone receiving antenna system, the base station has N{[ receiving antennas, each of which receives radio waves from its own communication zone and radio waves from an adjacent communication zone, and receives these two radio waves. One of them is distributed as a radio wave signal of the adjacent communication zone to the receiving device of the adjacent communication zone.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of reception antennas for multiple sectors according to an embodiment of the present invention, and FIG. This figure shows a configuration diagram of a receiving system of a receiving device that distributes waves and selects one of the received waves of good quality.

First, in FIG. 1, reception antennas 1 to 1 corresponding to each reception area are located near the boundaries of the reception areas of the first to sixth sectors.
6 is placed. For example, the received signal of the first sector receives the main received wave of antenna 1 and the diversity received wave of antenna 2 as received waves of the first sector, and selects the one with a better S/N. From then on, the second sector is antenna 2.
and receives each received wave from antenna 3. Finally, the sixth sector receives the main reception wave with antenna 6, receives the diversity reception wave with antenna 1, and selects the one with better S/N.

Next, a receiving apparatus system corresponding to such a receiving antenna system will be explained with reference to FIG. 2.

The received wave of antenna 1 is transmitted to the subsequent two-way divider (hereinafter referred to as 2) shown in the figure.
Due to a decrease in the level due to IB (called DIV),
In order to compensate for the deterioration of N, after amplification with a low noise amplifier (LN AMP in the figure) IA, 2DIV-IB
The signal is divided into two parts: the main received wave and the diversity received wave for the adjacent sixth sector. The 2DIV-IB main reception wave and the diversity reception wave received by the adjacent second antenna are demodulated by the reception demodulator 11C and IID, and a good S/N is selected and connected to each communication channel. The same operation as described above is also performed in the other second to sixth sectors.

Next, the characteristics of the gain pattern in the horizontal plane of the antenna when six sectors are covered by six receiving antennas will be explained with reference to the characteristic diagram of FIG. In Figure 3, the solid line gain pattern has a gain half width (3dB down width) of 60'.
The dotted line gain pattern is a gain pattern showing the characteristic of constant electric field lines. As shown in the figure, the contours of the isoelectric field lines cover a range of 120°. Now, the coverage range of the antenna gain patterns of the l-th sector and the second sector is shown in the characteristic diagram of FIG. That is, the isoelectric field lines of the antenna l (dotted chain line) and the isoelectric field lines of the antenna 2 (dotted lines) overlap in the first sector and cover the reception area.

Therefore, when antenna 1 receives the main reception wave, antenna 2 can operate as the diversity reception wave.

Note that the directional direction of the transmitting antenna installed at the base station radiates radio waves toward the center of each sector area, which is shifted by 30 degrees from the directional direction of the receiving antenna.

〔Effect of the invention〕

As explained above, the present invention is applicable to a mobile communication system in which a base station receives signals from surrounding areas in six sectors, and a receiver performs space diversity reception.
Conventionally, by amplifying the received waves of six receiving antennas arranged at 6° intervals using low-noise amplifiers, and then dividing them into two, and using one half for space diversity reception of the adjacent sector, the six-sector This method has the advantage of reducing the number of receiving antennas required from 12 to 6.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of an embodiment of the present invention, Figure 2 is a configuration diagram of a receiving system of this embodiment, Figures 3 and 4 are characteristic diagrams of the antenna of this embodiment, and Figure 5 is FIG. 2 is an explanatory diagram of a conventional multi-zone receiving antenna system. 1-6...Antenna, IA-6A...
Low noise amplifier (LN AMP), 1B to 6B...
・・2 divider (2-DIV), IIC~16C・・・・
...Reception demodulator, 11D to 16D...Reception demodulator, 21 to 26...First sector to sixth sector,
27A to 32A, 27 to 32B... Antenna.

Claims (1)

[Claims] In a multi-zone receiving antenna system in which N (N is an integer) communication zones are arranged around a wireless communication base station, and mobile stations in each communication zone and the base station perform space diversity reception, the base station has N receiving antennas, each of the receiving antennas receives radio waves of its own communication zone and radio waves of an adjacent communication zone, and one of these two radio waves is used as a radio wave signal of the adjacent communication zone. A multi-zone receiving antenna system characterized by distribution to receiving devices in adjacent communication zones.