Communications: radio wave antennas – Antennas – With coupling network or impedance in the leadin
Reexamination Certificate
2001-07-12
2003-02-18
Wong, Don (Department: 2821)
Communications: radio wave antennas
Antennas
With coupling network or impedance in the leadin
C370S342000
Reexamination Certificate
active
06522307
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a W-CDMA (Wideband-CDMA) system, and more particularly, to an antenna sharing apparatus of a base station for sharing an existing antenna in case of increasing a frequency allocation.
2. Description of the Background Art
In general, a W-CDMA system provides a voice and a data communication service. A channel signal transmitted from a terminal is transmitted through various radio paths to a base station.
At this time, an interruption occurs between signals having different receiving paths among signals transmitted from the base station, causing a fading phenomenon that an attenuation rate varies as time elapses, which triggers an error of a reception signal in the base station.
Therefore, in order to minimize such a fading phenomenon, the base station synthesizes an output of an antenna by a space diversity method, that is, by using two reception antennas.
If a resource at a frequency band for service is not sufficient, the frequency bands (FA), a plurality of communication channels, are positioned mutually adjacent without a guard band.
Accordingly, unlike a PCS system having the guard band, the WLL-CDMA system separately installs a transmission-reception antenna by frequency bands and operates it.
FIG. 1
is a drawing illustrating a related art antenna sharing apparatus of a base station using a single frequency band.
As shown in
FIG. 1
, a conventional antenna sharing apparatus of a base station includes a transmission-reception antenna
10
, a receiving dedicated antenna
12
and a duplexer
20
.
The antenna
10
is used as a transmission antenna, while the antennas
10
and
12
are used as the first and the second reception antennas for a space diversity.
Since the antenna
10
can be used both for transmission and reception, the duplexer
20
separates a transmission signal (Tx
1
) and a reception signal (Rx
1
) by using a filtering function. That is, the duplexer
20
outputs a transmission signal (Tx
1
) provided from the base station to the antenna
10
, and outputs the reception signal (Rx
1
) inputted through the antenna
10
to the base station.
Accordingly, the base station synthesizes the reception signals (Rx
1
and Rx
1
′) inputted through the antennas
10
and
12
to prevent the fading phenomenon.
Generally, the WLL-CDMA system is allocated a specific frequency and provides a radio communication service to subscribers.
At this time, the radio frequency allocation is made in consideration of the number of expected subscribers, and the radio frequency is additionally allocated according to change in the number of the subscribers.
Accordingly, in case that a frequency allocation is additionally made in line with an increase in the number of the subscribers, the antenna needs to be additionally installed corresponding to the added frequency allocation.
For example, if a single frequency band (1 FA) is used, as shown in FIG.
1
, two antennas are required. If two frequency bands (2 FA) are used, as shown in
FIG. 2
, two more antennas need to be installed.
In this manner, whenever the FA is increased, two antennas are additionally increased, causing a problem that an antenna installation cost is additionally incurred due to the increasing number of antennas.
In addition, in the conventional antenna sharing apparatus, between the duplexer
20
and the antennas
10
and
12
is a wired section to be connected by a cable directly by a person.
Consequently, in consideration of the fact that the WLL-CDMA system is installed and operated in an area where a wired telephone network is hardly adopted, additional installation of the antenna in line with the increase in the frequency allocation is practically difficult.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide an antenna sharing apparatus of a base station in a W-CDMA system that is capable of reducing an expense by minimizing the number of antenna in case of additional frequency allocation.
To achieve at least the above objects in whole or in parts, there is provided a W-CDMA system including a plurality of antenna sharing apparatuses of a base station having a LAN for receiving a first reception signal for a space diversity from a transmission-reception antenna, low-noise amplifying it and separately outputting it to a first and a second paths, and a band-pass filter for filtering a second reception signal for a space diversity, wherein the second path of each antenna sharing apparatus is connected to an input terminal of the band-pass filter of a different antenna sharing apparatus.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
REFERENCES:
patent: 5061937 (1991-10-01), Ozeki et al.
patent: 5289499 (1994-02-01), Weerackody
patent: 5781541 (1998-07-01), Schneider
patent: 5790588 (1998-08-01), Fukawa et al.
patent: 5832389 (1998-11-01), Dent
patent: 5867763 (1999-02-01), Dean et al.
patent: 5926503 (1999-07-01), Kelton et al.
patent: 6052366 (2000-04-01), Suzuki
patent: 6088570 (2000-07-01), Komara et al.
Clinger James
Fleshner & Kim LLP
Wong Don
LandOfFree
Antenna sharing apparatus of base station in W-CDMA system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antenna sharing apparatus of base station in W-CDMA system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antenna sharing apparatus of base station in W-CDMA system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3167913