Title of Invention

A TRANSCEIVER SYSTEM INCLUDING MULTIPLE RADIO BASE STATIONS THAT SHARE IN ANTENNA AND A METHOD FOR CONSTRUCTING A TRANSCEIVER SYSTEM

Abstract A transceiver system is described herein that has an antenna coupled to a filter unit which is coupled to multiple radio base stations (RBSs). Each RBS uses one TX/RX cable and if needed a RX cable to connect to the filter unit. To enable the RBSs so they can share one antenna, each RBS has a duplex filter incorporated therein. And, the filter unit has a unique combination of diplex filter(s), duplex filter(s), part-band duplex filter(s), diplex-duplex filter(s), splitter(s) and/or low noise amplifier(s). Four exemplary embodiments of the transceiver system are described herein to show how the filter unit can be configured so as to enable the RBSs to share one antenna even if the RBSs share the same frequency band and/or even if the RBSs operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM). Also described herein in accordance with the present invention are: (1) a method for constructing the transceiver system; (2) a radio base station; and (3) an antenna.
Full Text

BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates in general to the telecommunications field and, in particular,
to a transceiver system that includes multiple radio base stations (RBSs) that can share an
antenna even if the RBSs share a frequency band and/or even if the RBSs operate with different
radio standards.
Description of Related Art
It is well known when an operator places two or more RBSs in a transceiver system or
adds a new RBS to the transceiver system that the operator would like to have the RBSs share
the same antenna system. An example of a traditional transceiver system with multiple RBSs
that share the same antenna is briefly discussed below with respect to FIGURE 1.
Referring to FIGURE 1 (PRIOR ART), there is shown a block diagram of a traditional
transceiver system 100 described in PCT Patent Application No. WO 92/12579. The traditional
transceiver system 100 includes several base stations (BS1, BS2, BS3...BSn) each of which can
belong to a different type of radio system such as TACS, ETACS and GSM.
The base stations (BS1, BS2, BS3...BSn) are connected to a filter means 102 which in turn is
connected to an antenna 104. The filter means 102 filters the TX signals that are sent over TX
cables 106 from the base stations (BS1, BS2, BS3...BSn) and applies the filtered TX signals to
the antenna 104. The filter means 102 also filters RX signals received by the antenna 104. The
filtered RX signals are then sent to a divider unit 108. The divider unit 108 divides the filtered
RX signals so that separate filtered RX signals can be sent over RX
cables 110 to the base stations (BS1, BS2, BS3...BSn). A drawback of this particular
transceiver system 100 is that each base station (BS1, BS2, BS3...BSn) needs to use
two cables~TX cable 106 and RX cable 110—to share the antenna 104 which adds to the
complexity and cost of the transceiver system 100. It should be noted that U.S. Patent No.
5,781,865 discloses a transceiver system that is similar to and has the same drawbacks as
transceiver system 100. It should be further noted that EP 1320146 discloses a transceiver
system incorporating a diplexer in order to separate bands and standards to bring compatibility
of a shared antenna with multiple radio base stations. Accordingly, there is a need for a


transceiver system that addresses and solves the aforementioned drawback associated with
the traditional transceiver system 100. This need and other needs are addressed by the
transceiver systems of the present invention.
BRIEF DESCRIPTION OF THE INVENTION
The present invention includes a transceiver system that has an antenna coupled to
a filter configuration which is coupled to multiple radio base stations (RBSs). Each RBS
uses one TX/RX cable and if needed a RX cable to connect to the filter configuration. To
enable the RBSs so they can share one antenna, each RBS has a duplex filter incorporated
therein. And, the filter configuration has a unique combination of diplex filter(s), duplex
filter(s), part-band duplex filter(s), diplex-duplex filter(s), splitter(s) and/or low noise
amplifier(s). Four exemplary embodiments of the transceiver system are described below
to show how the filter configuration can be configured so as to enable the RBSs to share
one antenna even if the RBSs share the same frequency band and/or even if the RBSs
operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM). The
present invention described herein also includes: (1) a method for constructing the
transceiver system; (2) a radio base station; and (3) an antenna.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be obtained by
reference to the following detailed description when taken in conjunction with the
accompanying drawings wherein:
FIGURE 1 (PRIOR ART) is a block diagram of a traditional transceiver system that was
disclosed in PCT Patent Application No. WO 92/12579;
FIGURE 2 is a block diagram showing the basic components of a transceiver system in
accordance with the present invention;
FIGURE 3A is a block diagram showing the basic components of a first embodiment of
the transceiver system shown in FIGURE 2 in accordance with the present invention;


FIGURE 3B is a diagram showing exemplary frequency allocations associated with the
transceiver system shown in FIGURE 3A in accordance with the present invention;
FIGURE 4A is a block diagram showing the basic components of a second embodiment of
the transceiver system shown in FIGURE 2 in accordance with the present invention;
FIGURE 4B is a diagram showing exemplary frequency allocations associated with the
transceiver system shown in FIGURE 4A in accordance with the present invention;
FIGURE 5A is a block diagram showing the basic components of a third embodiment of
the transceiver system shown in FIGURE 2 in accordance with the present invention;
FIGURE 5B is a diagram showing exemplary frequency allocations associated with the
transceiver system shown in FIGURE 5A in accordance with the present invention;
FIGURE 6A is a block diagram showing the basic components of a fourth embodiment of
the transceiver system shown in FIGURE 2 in accordance with the present invention;
FIGURE 6B is a diagram showing exemplary frequency allocations associated with the
transceiver system shown in FIGURE 6A in accordance with the present invention; and
FIGURE 7 is a flowchart illustrating the steps of a preferred method for constructing the
transceiver system shown in FIGURES 2, 3A, 4A, 5A and 6A in accordance with the
present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to FIGURE 2, there is shown a block diagram that illustrates the basic
components of a transceiver system 200 which has multiple RBSs (RBS1, RBS2...RBSn)
that can share one antenna 202 in accordance with the present invention. As shown, the
transceiver system 200 includes an antenna 202 which is coupled to a filter configuration
204 which in turn is coupled to multiple RBSs (RBS1, RBS2...RBSn). Each RBS (RBS1,
RBS2...RBSn) uses one TX/RX cable 206 and if needed a RX cable 207 (see FIGURES


3A and 5A) to connect to the filter configuration 204. To enable the RBSs (RBSl,
RBS2...RBSn) so they can share one antenna 202, each RBS (RBSl, RBS2...RBSn) has a
duplex filter 208 incorporated therein. And, the filter configuration 204 has a unique
combination of diplex filter(s), duplex filter(s), part-band duplex filter(s), diplex-duplex
filter(s), splitter(s) and/or low noise amplifier LNA(s). Four different examples of how the
filter configuration 204 can be configured so as to enable the RBSs (RBSl, RBS2...RBSn)
to share one antenna 202 even if the RBSs (RBSl, RBS2...RBSn) share the same
frequency band and/or even if the RBSs (RBSl, RBS2...RBSn) operate with different
radio standards (e.g., TDMA, CDMA, WCDMA and GSM) are described below with
respect to FIGURES 3-6.
Referring to FIGURES 3A and 3B, there are shown two diagrams associated with
the first embodiment of the transceiver system 200a in accordance with the present
invention. As shown in FIGURE 3A, each of the RBSs (RBSl, RBS2...RBSn) have two
branches (branch A and branch B). This is done since the transceiver system 200a
typically has three sectors and each sector normally has two separate antennas 202a' and
202a" with two separate RX branches so as to obtain the proper "RX diversity gain". The
need for "RX diversity gain" comes from the fact that in nature a radio signal "bounces"
on different things (e.g., buildings, mountains) and this leads to problematical multipath
fading. And, one way to lower the influence of multipath fading is to install two or more
antennas 202a' and 202a". The antennas 202a' and 202a" can be place 3-4m apart from
one another or the antennas 202a' and 202a" can be made to have a 90° phase difference
between themselves. However it should be appreciated that this transceiver system 200a
or any of the other transceiver systems described herein can also have just one branch and
one antenna like was shown in transceiver system 200 (see FIGURE 2).
For clarity branch A of transceiver system 200a is described first and then a brief
discussion is provided about branch B which has essentially the same filter configuration
as branch A. As shown in FIGURE 3A, the transceiver system 200a includes an antenna
202a' which is coupled to a filter configuration 204a' that in turn is coupled to branch A of
multiple RBSs (RBSl, RBS2...RBSn). Each RBS (RBSl, RBS2...RBSn) uses one TX/RX
cable 206a and if needed one RX cable 207a to connect to the filter configuration 204a'.


To enable the RBSs (RBSl, RBS2...RBSn) so they can share one antenna 202a', each RBS
(RBSl, RBS2...RBSn) has a duplex filter 208a incorporated therein. And, the filter
configuration 204a' has a unique configuration which in this embodiment includes a diplex
filter 302, one or more duplex filters 304 and 305 and a splitter 306. A detailed discussion
is provided next on how the filter configuration 204a' is configured so as to enable the
RBSs (RBSl, RBS2...RBSn) to share one antenna 202a even if the RBSs (RBSl,
RBS2...RBSn) share the same frequency band and/or even if the RBSs (RBSl,
RBS2...RBSn) operate with different radio standards (e.g., TDMA, CDMA, WCDMA and
GSM).
Referring to the filter components associated with RBSl and RBS2 shown in
transceiver system 200a, the filter configuration 204a' includes the diplex filter 302, the
duplex filter 304 and the splitter 306. The diplex filter 302 includes a full-band receiver
(RX) filter 308 and two part-band transceiver (TX) filters 310 and 312. As can be seen,
the full-band RX filter 308 is coupled to part-band TX1 filter 310. The duplex filter 304
includes a RX filter 314 and a TX filter 316. The TX filter 316 is coupled to the part-band
TX2 filter 312 located in the diplex filter 302. The first RBSl and in particular the duplex
filter 208a incorporated therein uses a TX/RX cable 206a to connect to the full-band RX
filter 308 and first part-band TX1 filter 310 in the diplex filter 302. In addition, the first
RBSl also includes a LNA 318 and a coupler 320 that interfaces with the splitter 306 via
the RX cable 207a. In this way, the splitter 306 can couple a RX signal received from the
full-band RX filter 308 in the diplex filter 302 to the RX filter 314 in the duplex filter 304.
It should be appreciated that the splitter 306 is used if more than one RBS is co-sited in the
transceiver system 200a. The second RBS2 and in particular the duplex filter 208a
incorporated therein uses a TX/RX cable 206a to connect to the duplex filter 304. The
RBS2 also includes a LNA 318. In view of this filter configuration, RBSl can receive a
RX signal applied to the antenna 202a' by way of the splitter 306 and transmit a TX signal
within a TX1 band using the antenna 202a'. Whereas, RBS2 can receive a RX signal
applied to the antenna 202a' and transmit a TX signal within a TX2 band using the antenna
202a'.


For each RBS in addition to RBSl and RBS2 that is within or added to the
transceiver system 200a, the filter configuration 204a' and in particular the diplex filter
302 would include another part-band transceiver (TX) filter 322 (shown as TX3 filter
322). The part-band TX3 filter 322 is coupled to the antenna 202a'. The filter
configuration 204a' would also include another duplex filter 305. The duplex filter 305
includes a RX filter 324 and a TX filter 326. The TX filter 326 is coupled to the part-band
TX3 filter 322 in the diplex filter 302. The additional RBS (shown as RBSn) and in
particular the duplex filter 208a incorporated therein uses a TX/RX cable 206a to connect
to the duplex filter 305. The RBSn also includes a LNA 318. In view of this filter
configuration, RBSn can receive a RX signal applied to the antenna 202a' by way of the
splitter 306 and transmit a TX signal within a TX3 band using the antenna 202a'. The
same filter scheme associated with filter configuration 204a' is used to make filter
configuration 204a" which is associated with branch B of the RBSs (RBSl, RBS2...RBSn)
that share antenna 202a".
Referring to FIGURE 3B, there is a diagram showing exemplary frequency
allocations for each of the antennas 202a' and 202a" in transceiver system 200a. It is
possible to see how the RBSs (RBSl, RBS2...RBSn) can share the same frequency band
and can operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM)
simply by selecting the appropriate RX and TX filters. For instance, it can be seen that
RBSl branch A can operate on one standard using TX1 while RBSl branch B can operate
in the same or another standard using TX4. And, it can be seen that RBSl branch A and
RBSl branch B have RX diversity because both have the same RX band. Moreover, it
should be appreciated that if the RBSs (RBSl, RBS2...RBSn) use different standards then
there must be guardbands in the frequency allocation to separate the TX bands otherwise
there will be interactions between the TXs. These guardbands could be very narrow
however there is going to be a tradeoff between insertion loss and guardband attenuation.
Referring to FIGURES 4A and 4B, there are shown two diagrams associated with
the second embodiment of the transceiver system 200b in accordance with the present
invention. Like in the first embodiment of the present invention, transceiver system 200b
and in particular each of the RBSs (RBSl, RBS2...RBSn) have two branches (branch A


and branch B). For clarity branch A of transceiver system 200b is described first and then
a brief discussion is provided about branch B which has essentially the same filter
configuration as branch A.
As shown in FIGURE 4A, the transceiver system 200b includes an antenna 202b'
which is coupled to a filter unit 204b' that in turn is coupled to branch A of multiple RBSs
(RBS1, RBS2...RBSn). Each RBS (RBS1, RBS2...RBSn) uses one TX/RX cable 206b to
connect to the filter unit 204b'. To enable the RBSs (RBS1, RBS2...RBSn) so they can
share one antenna 202b', each RBS (RBS1, RBS2...RBSn) has a duplex filter 2008b
incorporated therein. And, the filter unit 204b' has a unique configuration which in this
embodiment includes a part-band duplex filter 402. A detailed discussion is provided next
on how the filter unit 204b' is configured so as to enable the RBSs (RBS1, RBS2...RBSn)
to share one antenna 202b' even if the RBSs (RBS1, RBS2...RBSn) share the same
frequency band and/or even if the RBSs (RBS1, RBS2...RBSn) operate with different
radio standards (e.g., TDMA, CDMA, WCDMA and GSM).
Referring to the filter components associated with RBS1 and RBS2 shown in
transceiver system 200b, the filter unit 204b' includes the part-band duplex filter 402
which is coupled to the antenna 202b'. The part-band duplex filter 402 includes two part-
band receiver (RX) filters 404 and 406 and two part-band transceiver (TX) filters 408 and
410. As can be seen, the first part-band RX1 filter 404 is coupled to the first part-band
TX1 filter 408. And, the second part-band RX2 filter 406 is coupled to the second part-
band TX2 filter 410. The first RBS1 and in particular the duplex filter 208b incorporated
therein uses a TX/RX cable 206b to connect to the first part-band RX1 filter 404 and first
part-band TX1 filter 408 in the part-band duplex filter 402. In addition, the first RBS1
also includes a LNA 412 which is coupled to the duplex filter 208b. The second RBS2
and in particular the duplex filter 208b incorporated therein uses a TX/RX cable 206b to
connect to the second part-band RX2 filter 406 and second part-band TX2 filter 410 in the
part-band duplex filter 402. The second RBS2 also includes a LNA 412 which is coupled
to the duplex filter 208b. In view of this filter unit, RBS1 can receive a RX signal within a
RX1 band that is applied to the antenna 202b' and transmit a TX signal within a TX1 band
using the antenna 202b'. Whereas, RBS2 can receive a RX signal within a RX2 band that

is applied to the antenna 202b' and transmit a TX signal within a TX2 band using the
antenna 202b'.
For each RBS in addition to RBS1 and RBS2 that is within or added to the
transceiver system 200b, the filter unit 204b' and in particular the part-band duplex filter
402 would include another part-band receiver (RX) filter 414 (shown as RX3 filter 414)
and another part-band transceiver (TX) filter 416 (shown as TX3 filter 416). The part-
band RX3 filter 414 is coupled to part-band TX3 filter 416. The additional RBS (shown
as RBSn) and in particular the duplex filter 208b incorporated therein uses a TX/RX cable
206b to connect to the part-band RX3 filter 414 and part-band TX3 filter 416 in the part-
band duplex filter 402. In addition, the RBSn also includes a LNA 412 which is coupled
to the duplex filter 208b. The same filter scheme associated with filter unit 204b' is used
make filter unit 204b" which is associated with branch B of the RBSs (RBS1,
RBS2...RBSn) that share antenna 202b".
Referring to FIGURE 4B, there is a diagram showing exemplary frequency
allocations for each of the antennas 202b' and 202b" in transceiver system 200b. It is
possible to see how the RBSs (RBS1, RBS2...RBSn) can share the same frequency band
and can operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM)
simply by selecting the appropriate RX and TX filters. For instance, it can be seen that
RBS2 branch A can operate on one standard using TX2 while RBS2 branch B can operate
in the same or another standard using TX5. And, it can be seen that RBS2 branch A and
RBS2 branch B do not have RX diversity because both have different RX bands where
RX2 does not match RX5.
Referring to FIGURES 5A and 5B, there are shown two diagrams associated with
the third embodiment of the transceiver system 200c in accordance with the present
invention. Like in the first two embodiments of the present invention, transceiver system
200c and in particular each of the RBSs (RBS1, RBS2...RBSn) have two branches (branch
A and branch B). For clarity branch A of transceiver system 200c is described first and
then a brief discussion is provided about branch B which has essentially the same filter
unit as branch A.


As shown in FIGURE 5A, the transceiver system 200c includes an antenna 202c'
which is coupled to a filter configuration 204c' that in turn is coupled to branch A of
multiple RBSs (RBS1, RBS2...RBSn). Each RBS (RBS1, RBS2...RBSn) uses a TX/RX
cable 206c and if needed one RX cable 207c to connect to the filter configuration 204c'.
To enable the RBSs (RBS1, RBS2...RBSn) so they can share one antenna 202c', each RBS
(RBS1, RBS2...RBSn) has a duplex filter 208c incorporated therein. And, the filter
configuration 204c' has a unique configuration which in this embodiment includes a
diplex-duplex filter 502 and may have a splitter 504 (if there are more than one cosited
RBS). A detailed discussion is provided next on how the filter configuration 204c' is
configured so as to enable the RBSs (RBS1, RBS2...RBSn) to share one antenna 202c'
even if the RBSs (RBS1, RBS2...RBSn) share the same frequency band and/or even if the
RBSs (RBS1, RBS2...RBSn) operate with different radio standards (e.g., TDMA, CDMA,
WCDMA and GSM).
Referring to the filter components associated with RBS1 and RBS2 shown in the
transceiver system 200c, the filter configuration 204c' includes the diplex-duplex filter
502 and the splitter 504. The diplex-duplex filter 502 includes two full-band receiver
(RX) filters 506 and 508 and two part-band transceiver (TX) filters 510 and 512. As can
be seen, the first full-band RX filter 506 is coupled to the first part-band TXl filter 510.
And, the second full-band RX filter 508 is coupled to the second part-band TX2 filter 512
but is not coupled to the antenna 202c'. The first RBS1 and in particular the duplex filter
208c incorporated therein uses a TX/RX cable 206c to connect to the full-band RX filter
506 and first part-band TXl filter 510 in the diplex-duplex filter 502. In addition, the first
RBS1 also includes a low noise amplifier (LNA) 514 and a coupler 516 that interfaces
with the splitter 504 via the RX cable 207c. In this way, the splitter 504 can couple a RX
signal received from the full-band RX filter 506 in diplex-duplex filter 502 to the RX filter
508 in diplex-duplex filter 502. The second RBS2 and in particular the duplex filter 208c
incorporated therein uses a TX/RX cable 206c to connect to the second full-band RX filter
508 and second part-band TX2 filter 512 in the diplex-duplex filter 502. The second
RBS2 also includes a LNA 514. In view of this filter unit, RBS1 can receive a RX signal
applied to the antenna 202c' and transmit a TX signal within a TXl band using the antenna


202c'. Whereas, RBS2 can receive a RX signal applied to the antenna 202c' by way of the
splitter 504 and transmit a TX signal within a TX2 band using the antenna 202c'.
For each RBS in addition to RBS1 and RBS2 that is within or added to the
transceiver system 200c, the filter configuration 204c' and in particular the diplex-duplex
filter 502 would include another full-band receiver (RX) filter 518 (shown as RX filter
518) and another part-band transceiver (TX) filter 520 (shown as TX3 filter 520). The
full-band RX filter 518 is coupled to part-band TX3 filter 520 but is not coupled to the
antenna 202c'. The additional RBS (shown as RBSn) and in particular the duplex filter
208c incorporated therein uses a TX/RX cable 206c to connect to the diplex-duplex filter
502. The RBSn also includes a LNA 514. In view of this filter unit, RBSn can receive a
RX signal applied to the antenna 202c' by way of the splitter 504 and transmit a TX signal
within a TX3 band using the antenna 202c'. The same filter scheme associated with filter
configuration 204c' is used to make filter configuration 204c" which is associated with
branch B of the RBSs (RBS1, RBS2...RBSn) that share antenna 202c".
Referring to FIGURE 5B, there is a diagram showing exemplary frequency
allocations for each of the antennas 202c' and 202c" in transceiver system 200c. It is
possible to see how the RBSs (RBS1, RBS2...RBSn) can share the same frequency band
and can operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM)
simply by selecting the appropriate RX and TX filters. For instance, it can be seen that
RBS1 branch A can operate on one standard using TX1 while RBS1 branch B can operate
on the same or another standard using TX4. And, it can be seen that RBS 1 branch A and
RBS1 branch B have RX diversity because both have the same RX band.. It can be seen
that RBS2 can work in the adjacent band with a different standard.
In comparing transceiver systems 200a and 200c, it should be noted that
transceiver system 200c has a lower insertion loss (~1dB) than transceiver system 200a.
Because, the TX signals transmitted from the RBS2s pass through one filter 512 in the
transceiver system 200c and pass through two TX filters 312 and 316 in the transceiver
system 200a. Also, it should be noted that transceiver system 200c uses one diplex-duplex


filter 502 while transceiver system 200a uses a diplex filter 302 and a separate duplex
filter 304 per branch.
Referring to FIGURES 6A and 6B, there are shown two diagrams associated with
the fourth embodiment of the transceiver system 200d in accordance with the present
invention. Like in the first three embodiments of the present invention, transceiver system
200d and in particular each of the RBSs (RBS1, RBS2...RBSn) have two branches (branch
A and branch B). For clarity branch A of transceiver system 200d is described first and
then a brief discussion is provided about branch B which has essentially the same filter
unit as branch A.
As shown in FIGURE 6A, the transceiver system 200d includes an antenna 202d'
which is coupled to a filter unit 204d' that in turn is coupled to branch A of multiple RBSs
(RBS1, RBS2...RBSn). Each RBS (RBS1, RBS2...RBSn) uses a TX/RX cable 206d to
connect to the filter unit 204d'. To enable the RBSs (RBS1, RBS2...RBSn) so they can
share one antenna 202d', each RBS (RBS1, RBS2...RBSn) has a duplex filter 208d
incorporated therein. And, the filter unit 204d' has a unique configuration which in this
embodiment includes a diplex-duplex filter 602 and may have a low noise amplifier
(LNA) 604 with a splitter function. A detailed discussion is provided next on how the
filter unit 204d' is configured so as to enable the RBSs (RBS1, RBS2...RBSn) to share one
antenna 202d' even if the RBSs (RBS1, RBS2...RBSn) share the same frequency band
and/or even if the RBSs (RBS1, RBS2...RBSn) operate with different radio standards (e.g.,
TDMA, CDMA, WCDMA and GSM).
. Referring to the filter components associated with RBS1 and RBS2 shown in the
transceiver system 200d, the filter unit 204d' includes the diplex-duplex filter 602, the
LNA 604 and a splitter function. The diplex-duplex filter 602 includes two full-band
receiver (RX) filters 606 and 608 and two part-band transceiver (TX) filters 610 and 612.
As can be seen, the first full-band RX filter 606 is coupled by way of the LNA 604 to the
first part-band TXl filter 610. And, the second full-band RX filter 608 is coupled to the
second part-band TX2 filter 612 but is not coupled to the antenna 202d'. The first RBS1
and in particular the duplex filter 20 8d incorporated therein uses a TX/RX cable 206d to


connect to the LNA 604 and the first part-band TX1 filter 610 in the diplex-duplex filter
602. In addition, the first RBS1 also includes a low noise amplifier (LNA) 614. The LNA
604 can couple a RX signal received from the full-band RX filter 606 in diplex-duplex
filter 602 to the RX filter 608 in diplex-duplex filter 602. The second RBS2 and in
particular the duplex filter 208d incorporated therein uses a TX/RX cable 206d to connect
to the second full-band RX filter 608 and second part-band TX2 filter 612 in the diplex-
duplex filter 602. The second RBS2 also includes a LNA 614. In view of this filter unit,
RBS1 can receive a RX signal applied to the antenna 202d' by way of the LNA 604 and
transmit a TX signal within a TX1 band using the antenna 202d'. Whereas, RBS2 can
receive a RX signal applied to the antenna 202d' by way of the LNA 604 and transmit a
TX signal within a TX2 band using the antenna 202d'.
For each RBS in addition to RBS1 and RBS2 that is within or added to the
transceiver system 200d, the filter unit 204d' and in particular the diplex-duplex filter 602
would include another full-band receiver (RX) filter 618 (shown as RX filter 618) and
another part-band transceiver (TX) filter 620 (shown as TX3 filter 620). The full-band RX
filter 618 is coupled to the LNA 604 and the part-band TX3 filter 620 but is not coupled to
the antenna 202d'. The additional RBS (shown as RBSn) and in particular the duplex filter
208d incorporated therein uses a TX/RX cable 206d to connect to the diplex-duplex filter
602. The RBSn also includes a LNA 614. In view of this filter unit, RBSn can receive a
RX signal applied to the antenna 202d' by way of the LNA 604 and transmit a TX signal
within a TX3 band using the antenna 202d'. The same filter scheme associated with filter
unit 204d' is used to make filter unit 204d" which is associated with branch B of the RBSs
(RBS1, RBS2...RBSn) that share antenna 202d".
Referring to FIGURE 6B, there is a diagram showing exemplary frequency
allocations for each of the antennas 202d' and 202d" in transceiver system 200d. It is
possible to see how the RBSs (RBS1, RBS2...RBSn) can share the same frequency band
and can operate with different radio standards (e.g., TDMA, CDMA, WCDMA and GSM)
simply by selecting the appropriate RX and TX filters. For instance, it can be seen that
RBS1 branch A can operate on one standard using TX1 while RBS1 branch B can operate
on the same or another standard using TX4. And, it can be seen that RBS1 branch A and


RBS1 branch B have RX diversity because both have the same RX band. It can be seen
that RBS2 can work in the adjacent band with a different standard.
In comparing transceiver systems 200c and 200d, it is noted that transceiver system
200d does not have a coupler 516 and accompanying RX cable 207c in the RBS1 nor does
it have the splitter 504 like shown in transceiver system 200c. However, the transceiver
system 200d does have an additional active component LNA 604 outside of the RBSs.
Moreover, the transceiver system 200d and in particular the RBS1 has a slightly worse RX
performance than the RBS1 in transceiver system 200c.
It should be appreciated that in all of the filter configurations described above that
a "Tower mounted amplifier" (TMA) (not shown) could be easily incorporated therein if
needed. And, in FIGURES 3A and 5A where the filter configurations included a splitter
there is however another way of implementing this splitting function and that is to install 2
couplers in the RBS.
It should be understood that certain details and components associated with
transceiver systems 200a, 200b, 200c and 200d are well known in the industry. Therefore,
for clarity, the description provided above omitted those well known details and
components of the transceiver systems 200a, 200b, 200c and 200d that are not necessary
to understand the present invention. Lastly, it should be understood that a diplex filter
normally filters signals in one band (e.g., 1900 band) from another band (e.g., 800 band).
And, a duplex filter filters a TX band from a RX band.
Referring to FIGURE 7, there is a flowchart illustrating the steps of a preferred
method 700 for constructing the transceiver system 700 shown in FIGURES 2, 3A, 4A,
5A and 6A in accordance with the present invention. Beginning at step 702, one antenna
202 is provided for each branch of the RBSs used in the transceiver system 200. At step
704, a filter configuration 204 is provided that has a unique combination of diplex filter(s),
duplex filter(s), part-band duplex filter(s), diplex-duplex filter(s), splitter(s) and/or LNA(s)
(see FIGURES 3A, 4A, 5A and 6A). At step 706, at least two radio base stations RBSs
(RBS1, RBS2...RBSn) are provided where each RBS (RBS1, RBS2...RBSn) has a duplex


filter 208 incorporated therein. Each RBS (RBS1, RBS2...RBSn) and in particular each
duplex filter 208 is coupled to the filter configuration 204 which is configured in a manner
that enables all of the RBSs (RBS1, RBS2...RBSn) to share the antenna 202 even if the
RBSs (RBS1, RBS2...RBSn) share a frequency band and even if the RBSs (RBS1,
RBS2...RBSn) operate with different radio standards (e.g., TDMA, CDMA, WCDMA and
GSM). Four exemplary configurations of the filter configuration 204 have been described
above with respect to FIGURES 3-6.
Although four embodiments of the present invention have been illustrated in the
accompanying Drawings and described in the foregoing Detailed Description, it should be
understood that the invention is not limited to the embodiments disclosed, but is capable of
numerous rearrangements, modifications and substitutions without departing from the
spirit of the invention as set forth and defined by the following claims.


WE CLAIM :
1. A transceiver system (200) comprising:
an antenna (202);
a filter unit (204) coupled to said antenna and to a plurality of radio base stations
(RBS1.RBS2 RBSN);
characterized in that
each of the radio base stations have a duplex filter (208) incorporated therein all of
which are coupled to said filter unit (204), the filter unit being configured to allow said
radio base stations to share said antenna (202) even if said radio base stations share
a frequency band and even if said radio base stations operate with different radio
standards.
2. The transceiver system of Claim 1, wherein said filter unit comprises:
a diplex filter, coupled to said antenna, said diplex filter comprises:
a full-band receiver (RX) filter; and
two part-band transceiver (TX) filters, where said full-band RX filter is coupled
to the first part-band TX filter; and
a first duplex filter that comprises:
a TX filter coupled to the second part-band TX filter in said diplex filter; and
a RX filter; and
said first radio base station having a duplex filter incorporated therein that is coupled
to the full-band RX filter and the first part-band TX filter in said diplex filter;
said first radio base station also interfaces with a splitter that couples a RX signal
received from the full-band RX filter in said diplex filter to the RX filter in said first
duplex filter; and
said second radio base station having a duplex filter incorporated therein that is
coupled to the TX filter and the RX filter in said first duplex filter.
3. The transceiver system of Claim 2, comprising :
said diplex filter comprising:
a third part-band transceiver (TX) filter; and
a second duplex filter that comprises:
a TX filter coupled to the third part-band TX filter in said diplex filter; and
a,RX filter; and

said third radio base station having a duplex filter incorporated therein that is
coupled to the TX filter and the RX filter in said second duplex filter that has
the RX filter which receives the RX signal from the splitter.
4. The transceiver system of Claim 1, wherein said filter unit comprises:
a part-band duplex filter, coupled to said antenna, said part-band duplex filter
comprises:
two part-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the first part-band RX filter is coupled to
the first part-band TX filter and where the second part-band RX filter is coupled to the
second part-band TX filter; and
said first radio base station having a duplex filter incorporated therein that is coupled
to the first part RX filter and the first part-band TX filter in said part-band duplex filter;
and
said second radio base station having a duplex filter incorporated therein that is
coupled to the second part-band RX filter and the second part-band TX filter in said
part-band duplex filter.
5. The transceiver system of Claim 4, comprising:
said part-band duplex filter comprising comprises:
a third part-band receiver (RX) filter; and
a third part-band transceiver (TX) filter, where the third part-band RX filter is coupled
to the third part-band TX filter; and
said third radio base station having a duplex filter incorporated therein that is
coupled to the third part-band RX filter and the third part-band TX filter in said part-
band duplex filter.
6. The transceiver system of Claim 1, wherein said filter unit comprises:
an antenna;
a diplex-duplex filter, coupled to said antenna, said diplex-duplex filter comprises:
two full-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the first full-band RX filter is coupled to
the first part-band TX filter and where the second full-band RX filter is coupled to the
second part-band TX filter; and
said first radio base station having a duplex filter incorporated therein that is coupled
to the first full-band RX filter and the first part-band TX filter in said diplex-duplex
filter;

said first radio base station also interfaces with a splitter that couples a RX signal
received from the first full-band RX filter to the second full-band RX filter in said
diplex-duplex filter, Wherein the second full-band RX filter is not connected to said
antenna; and.
said second radio base station having a duplex filter incorporated therein that is
coupled to the second full-band RX filter and the second part-band TX filter in said
diplex-duplex filter.
7. The transceiver system of Claim 6, comprising
said diplex-duplex filter comprising comprises:
a third full-band receiver (RX) filter; and
a third part-band transceiver (TX) filter, where the third full-band RX filter is coupled
to the third part-band TX filter; and
said third radio base station having a duplex filter incorporated therein that is coupled
to the third full-band RX filter and the third part-band TX filter in said diplex-duplex
filter, wherein the third full-band RX filter is not connected to said antenna but instead
receives the RX signal from the splitter.
8. The transceiver system of Claim 1, wherein said filter unit comprises:
an antenna;
a diplex-duplex filter, coupled to said antenna, said diplex-duplex filter comprises:
two full-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the second full-band RX filter is
coupled to the second part-band TX filter; and
said first radio base station having a duplex filter incorporated therein that is coupled
to the first full-band RX filter by way of a low noise amplifier and is also coupled to
first part-band TX filter in said diplex-duplex filter;
said low noise amplifier also couples a RX signal received from the first full-band RX
filter to the second full-band RX filter in said diplex-duplex filter, wherein the second
full-band RX filter is not connected to said antenna; and
said second radio base station having a duplex filter incorporated therein that is
coupled to the second full band RX filter and the second part-band TX filter in said
diplex-duplex filter.
9. The transceiver system of Claim 8, comprising
said diplex-duplex filter comprises:
a third full-band receiver (RX) filter; and

a third part-band transceiver (TX) filter, where the third full-band RX filter is coupled
to the third part-band TX filter; and
said third radio base station having a duplex filter incorporated therein that is coupled
to the third full-band RX filter and the third part-band TX filter in said diplex-duplex
filter, wherein the third full-band RX filter is not connected to said
antenna but instead receives the RX signal from the low noise amplifier.
10. The transceiver system of Claim 1 wherein said radio standards comprises:
time division multiple access (TDMA);
code division multiple access (CDMA);
wideband division multiple access (WCDMA); and
global system for mobile communication (GSM).
11. A method for constructing a transceiver system comprising the steps of:
providing an antenna (202);
providing a filter unit (204) coupled to the antenna; and
providing at least two radio base stations (RBS1, RBS2, RBSN) characterized in
that
each of the radio base stations have a duplex filter incorporated therein all of which
are coupled to said filter unit, the filter unit being configured to allow said radio base
stations share said antenna even if said radio base stations share a frequency band
and even if said radio base stations operate with different radio standards.
12. The method of Claim 11; wherein said filter unit comprises:
a diplex filter, coupled to said antenna, said diplex filter comprises:
a full-band receiver(RX) filter; and
two part-band transceiver (TX) filters, where said full-band RX filter is coupled to the
first part-band TX filter; and
a first duplex filter that comprises:
a TX filter coupled to the second part-band TX filter in said diplex filter; and
a RX filter; and
said first radio base station comprises the duplex filter incorporated therein
which is coupled to the full-band RX filter and the first part-band TX filter in said
diplex filter;
said first radio base station also interfaces with a splitter that couples a RX signal
received from the full-band RX filter in said diplex filter to the RX filter in said first
duplex filter; and

said second radio base station comprises the duplex filter incorporated therein which
is coupled to the TX filter and the RX filter in said first duplex filter.
13. The method of Claim 12, wherein said step of providing at least two radio base
stations comprises adding a new radio base station to the at least two radio base
stations in which case said diplex filter comprises:
a third part-band transceiver (TX) filter; and a second duplex filter that comprises:
a TX filter coupled tq the third part-band TX filter in said diplex filter; and
a RX filter; and
said new radio base station comprises a duplex filter incorporated therein which is
coupled to the TX filter and the RX filter in said second duplex filter that has the RX
filter which receives the RX signal from the splitter.
14. The method of Claim 11, wherein said filter unit comprises:
a part-band duplex filter, coupled to said antenna, said part-band duplex filter
comprises:
two part-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the first part-band RX filter is coupled to
the first part-band TX filter and where the second part-band RX filter is coupled to the
second part-band TX filter; and
said first radio base station comprises the duplex filter incorporated therein which is
coupled to the first part RX filter and the first part-band TX filter in said part-band
duplex filter; and
said second radio base station comprises the duplex filter incorporated therein which
is coupled to the second part-band RX filter and the second part-band TX filter in said
part-band duplex filter.
15. The method of Claim 14, wherein said step of providing at least two radio base
stations comprises adding a new radio base station to the at least two radio base
stations in which case said part-band duplex filter comprises :
a third part-band receiver (RX) filter; and
a third part-band transceiver (TX) filter, where the third part-band RX filter is
coupled to the third part-band TX filter; and
said new radio base station comprises a duplex filter incorporated therein which is
coupled to the third part-band RX filter and the third part-band TX filter in said part-
band duplex filter.

16. The method of Claim 11, wherein said filter unit comprises:
a diplex-duplex filter, coupled to said antenna, said diplex-duplex filter comprises:
two full-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the first full-band RX filter is coupled to
the first part-band TX filter and where the second full-band: RX filter is coupled to the
second part-band TX filter; and
said first radio base station comprises the duplex filter incorporated therein which
is coupled to the first full-band RX filter and the first part-band TX filter in said diplex-
duplex filter;
said first radio base station also interfaces with a splitter that couples a RX signal
received from the first full-band RX filter to the second full-band RX filter in said
diplex-duplex filter, wherein the second full-band RX filter is not connected to said
antenna; and
said second radio base station comprises the duplex filter incorporated therein
which is coupled to the second full-band RX filter and the second part-band TX filter
in said diplex-duplex filter.
17. The method of Claim 16, wherein said step of providing at least two radio base
stations comprises adding a new radio base station to the at least two radio base
stations in which case said diplex-duplex filter comprises:
a third full-band receiver (RX) filter; and
a third part-band transceiver (TX) filter, where the third full-band RX filter is
coupled to the third part-band TX filter; and
said new radio base station comprises a duplex filter incorporated therein which is
coupled to the third full-band RX filter and the third part-band TX filter in said diplex-
duplex filter, wherein the third full-band RX filter is not connected to said antenna but
instead receives the RX signal from the splitter.
18. The method of Claim 11, wherein said filter unit comprises:
a diplex-duplex filter, coupled to said antenna, said diplex-duplex filter comprises:
two full-band receiver (RX) filters; and
two part-band transceiver (TX) filters, where the second full-band RX filter is coupled
to the second part-band TX filter; and
said first radio base station comprises the duplex filter incorporated therein which is
coupled to the first full-band RX filter by way of a low noise amplifier and is also
coupled to first part-band TX filter in said diplex-duplex filter;

said low noise amplifier also couples a RX signal received from the first full-band RX
filter to the second full-band RX filter in said diplex-duplex filter, wherein the second
full-band RX filter is not connected to said antenna; and
said second radio base station comprises the duplex filter incorporated therein which
is coupled to the second full-band RX filter and the second part-band TX
filter in said diplex-duplex filter.
19. The method of Claim 18, wherein said step of providing at least two radio base
stations" comprises adding a new radio base station to the at least two radio base
stations in which case said diplex-duplex filter comprises:
a third full-band receiver (RX) filter; and
a third part-band transceiver (TX) filter, where the third full-band RX filter is coupled
to the third part-band TX filter; and
said third radio base station comprises a duplex filter incorporated therein which is
coupled to the third full-band RX filter and the third part-band TX filter in said diplex-
duplex filter, wherein the third full-band RX filter is not connected to said antenna but
instead receives the RX signal from the low noise amplifier.
20. The method of Claim 11 wherein said radio standards comprises:
time division multiple access (TDMA);
code division multiple access (CDMA);
wideband division multiple access (WCDMA); and
global system for mobile communication (GSM).



ABSTRACT


TRANSCEIVER SYSTEM INCLUDING MULTIPLE RADIO BASE STATIONS
THAT SHARE AN ANTENNA
A transceiver system is described herein that has an antenna coupled to a filter unit
which is coupled to multiple radio base stations (RBSs). Each RBS uses one TX/RX cable
and if needed a RX cable to connect to the filter unit. To enable the RBSs so they can
share one antenna, each RBS has a duplex filter incorporated therein. And, the filter unit
has a unique combination of diplex filter(s), duplex filter(s), part-band duplex filter(s),
diplex-duplex filter(s), splitter(s) and/or low noise amplifier(s). Four exemplary
embodiments of the transceiver system are described herein to show how the filter unit can
be configured so as to enable the RBSs to share one antenna even if the RBSs share the
same frequency band and/or even if the RBSs operate with different radio standards (e.g.,
TDMA, CDMA, WCDMA and GSM). Also described herein in accordance with the
present invention are: (1) a method for constructing the transceiver system; (2) a radio
base station; and (3) an antenna.

Documents:

02005-kolnp-2006 abstract.pdf

02005-kolnp-2006 claims.pdf

02005-kolnp-2006 correspondence others.pdf

02005-kolnp-2006 description (complete).pdf

02005-kolnp-2006 drawings.pdf

02005-kolnp-2006 form-1.pdf

02005-kolnp-2006 form-2.pdf

02005-kolnp-2006 form-3.pdf

02005-kolnp-2006 form-5.pdf

02005-kolnp-2006 international publication.pdf

02005-kolnp-2006 international search report.pdf

02005-kolnp-2006-correspondence others-1.1.pdf

02005-kolnp-2006-correspondence.pdf

02005-kolnp-2006-form-1-1.1.pdf

02005-kolnp-2006-form-18.pdf

2005-KOLNP-2006-(08-03-2013)-AMANDED PAGES OF SPECIFICATION.pdf

2005-KOLNP-2006-(08-03-2013)-CORRESPONDENCE.pdf

2005-KOLNP-2006-(08-03-2013)-DESCRIPTION (COMPLETE).pdf

2005-KOLNP-2006-(21-02-2013)-AMANDED PAGES OF SPECIFICATION.pdf

2005-KOLNP-2006-(21-02-2013)-CORRESPONDENCE.pdf

2005-KOLNP-2006-(22-11-2011)-CORRESPONDENCE.pdf

2005-KOLNP-2006-(24-12-2012)-CORRESPONDENCE.pdf

2005-KOLNP-2006-ABSTRACT.pdf

2005-KOLNP-2006-AMANDED CLAIMS.pdf

2005-KOLNP-2006-CANCELLED PAGES.pdf

2005-KOLNP-2006-CORRESPONDENCE.pdf

2005-KOLNP-2006-CORRESPONDENCE1.1.pdf

2005-KOLNP-2006-DESCRIPTION (COMPLETE)-1.1.pdf

2005-KOLNP-2006-DESCRIPTION (COMPLETE).pdf

2005-KOLNP-2006-DRAWINGS.pdf

2005-KOLNP-2006-EXAMINATION REPORT.pdf

2005-KOLNP-2006-FORM 1.pdf

2005-KOLNP-2006-FORM 18.pdf

2005-KOLNP-2006-FORM 2.pdf

2005-KOLNP-2006-FORM 3.1.1.pdf

2005-KOLNP-2006-GPA.pdf

2005-KOLNP-2006-GRANTED-ABSTRACT.pdf

2005-KOLNP-2006-GRANTED-CLAIMS.pdf

2005-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

2005-KOLNP-2006-GRANTED-DRAWINGS.pdf

2005-KOLNP-2006-GRANTED-FORM 1.pdf

2005-KOLNP-2006-GRANTED-FORM 2.pdf

2005-KOLNP-2006-GRANTED-FORM 3.pdf

2005-KOLNP-2006-GRANTED-FORM 5.pdf

2005-KOLNP-2006-GRANTED-SPECIFICATION-COMPLETE.pdf

2005-KOLNP-2006-ORDER.pdf

2005-KOLNP-2006-OTHERS 1.1.pdf

2005-KOLNP-2006-OTHERS DOCUMENTS.1.2.pdf

2005-KOLNP-2006-OTHERS.pdf

2005-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

2005-KOLNP-2006-REPLY TO EXAMINATION REPORT1.1.pdf

abstract-02005-kolnp-2006.jpg


Patent Number 255888
Indian Patent Application Number 2005/KOLNP/2006
PG Journal Number 14/2013
Publication Date 05-Apr-2013
Grant Date 28-Mar-2013
Date of Filing 17-Jul-2006
Name of Patentee TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Applicant Address S-164 83 STOCKHOLM
Inventors:
# Inventor's Name Inventor's Address
1 LINDELL, PATRIK MIDGÅRDSVÄGEN 10,S-191 45 SOLLENTUNA
2 SKARBY, ULF ROBURVÄGEN 20 ,S-181 33 LINDINGÖ
PCT International Classification Number H04B 1/38
PCT International Application Number PCT/SE2004/001670
PCT International Filing date 2004-11-15
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/743,555 2003-12-20 U.S.A.