FEEDER CABLE REDUCTION
Field of the Invention
[0001] The present invention relates to radio frequency communications,
and in particular to translating signals received at one frequency from multiple
antennas to being centered about different frequencies, and combining these
signals for delivery over a common antenna feeder cable.
Background of the Invention
[0002] In cellular communication environments, the electronics used to
facilitate receiving and transmitting signals is distributed between a base
housing and a masthead, which is mounted atop a building, tower, or like
mast structure. The actual antennas used for transmitting and receiving
signals are associated with the masthead. The masthead will generally
include basic electronics to couple the antennas to corresponding antenna
feeder cables, which connect to transceiver and amplifier electronics located
in the base housing.
[0003] Historically, the amount of electronics placed in the masthead has
been minimized, due to inhospitable environmental conditions, such as
lightning, wind, precipitation, and temperature extremes, along with the
difficulty in replacing the electronics when failures occur. Maintenance of the
masthead is time-consuming and dangerous, given the location of the
masthead. Minimizing the electronics in the masthead has resulted in
essentially each antenna being associated with a separate antenna feeder
cable.
[0004] As time progressed, the cost of the electronics has been greatly
reduced, whereas the cost of the antenna feeder cables has held relatively
constant, if not increased. Thus, a decade ago the antenna feeder cables
were an insignificant cost associated with a base station environment,
whereas today the cost of the antenna feeder cables is a significant portion of
the cost associated with the base station environment. Accordingly, there is a
need to minimize the number of antenna feeder cables associated with a base
station environment, without impacting the functionality or operability of the
base station environment. Further, there is a need to minimize the increase in
cost associated with the masthead and base housing electronics due to
minimizing the number of antenna feeder cables required to connect the
masthead electronics to the base housing electronics.
Summary of the Invention
[0005] The present invention allows transmission of multiple signals
between masthead electronics and base housing electronics in a base station
environment At least some of the received signals from the multiple
antennas are translated to being centered about different center frequencies,
such that the translated signals may be combined into a composite signal
including each of the received signals. The composite signal is then sent over
a single feeder cable to base housing electronics, wherein the received
signals are separated and processed by transceiver circuitry. Prior to being
provided to the transceiver circuitry, those signals that were translated from
being centered about one frequency to another may be retranslated to being
centered about the original center frequency. In one embodiment, the
multiple antennas represent main and diversity antennas. In such an
embodiment, the received signals from the diversity antenna(s) may be
translated and combined with the signal received from the main antenna. The
receive signal from the main antenna may or may not be translated prior to
combining with the translated signals from the diversity antenna(s). The
present invention is applicable in single mode and multi-mode environments.
It is also applicable to systems which use four branch receive diversity.
Future systems such as MIMO which may use two transmit signals and four
receive signals per sector will also greatly benefit from this invention. In
essence this invention can be leveraged in any deployment scenario where
there are more receive signals than transmit signals.
[0006] Those skilled in the art will appreciate the scope of the present
invention and realize additional aspects thereof after reading the following
detailed description of the preferred embodiments in association with the
accompanying drawing figures.
Brief Description of the Drawing Figures
[0007] The accompanying drawing figures incorporated in and forming a
part of this specification illustrate several aspects of the invention, and
together with the description serve to explain the principles of the invention.
[0008] FIGURE 1 is a block representation of a base station environment
according to one embodiment of the present invention.
[0009] FIGURE 2 is a block representation of base housing electronics and
masthead electronics according to a first embodiment of the present
invention.
[0010] FIGURE 3 is a graphical illustration of a frequency translation
process according to the embodiment of Figure 2.
[0011] FIGURE 4 is a block representation of base housing electronics and
masthead electronics according to a second embodiment of the present
invention.
[0012] FIGURE 5 is a graphical illustration of a frequency translation
process according to the embodiment of Figure 4.
[0013] FIGURE 6 is a block representation of base housing electronics and
masthead electronics according to a third embodiment of the present
invention.
Detailed Description of the Preferred Embodiments
[0014] The embodiments set forth below represent the necessary
information to enable those skilled in the art to practice the invention and
illustrate the best mode of practicing the invention. Upon reading the
following description in light of the accompanying drawing figures, those
skilled in the art will understand the concepts of the invention and will
recognize applications of these concepts not particularly addressed herein. It
should be understood that these concepts and applications fall within the
scope of the disclosure and the accompanying claims.
[0015] The present invention facilitates the reduction of cabling required in
a base station environment. In general, signals that were normally
transmitted over separate cables are frequency shifted about different center
frequencies, combined, and sent over a single cable. At a receiving end of
the cable, the combined signals are recovered and processed in traditional
fashion. The invention is particularly useful in a diversity environment,
wherein multiple antennas are used to receive a common signal. In such an
environment, certain of the signals received from the main and diversity
antennas are shifted in frequency, combined with one another, and
transmitted over a common cable. Accordingly, each sector, which includes a
main and one or more diversity antennas, will need only one cable for
transmitting the received signals from the antennas to electronics in a base
housing.
[0016] Prior to delving into the details of the present invention, an overview
of a base station environment 10 is illustrated in Figure 1 according to one
embodiment of the present invention. The illustrated base station
environment 10 is exemplary of the primary components in a cellular access
network. A base housing 12 is provided in a secure location in association
with a mast 14, which may be a tower or other structure near the top of which
is mounted a masthead 16. Communications for the base station
environment 10 are distributed between the masthead 16 and the base
housing 12. In particular, the base housing 12 will include base housing
electronics 18, which include the primary transceiver and power amplification
circuitry required for cellular communications. The masthead 16 will include
masthead electronics 20, which generally comprise the limited amount of
electronics necessary to operatively connect with multiple antennas 22, which
are mounted on the masthead 16. The masthead electronics 20 and the base
housing electronics 18 are coupled together with one or more feeder cables
24. For the illustrated embodiment, there are six antennas 22 divided into
three sectors having two antennas 22 each. For each sector, one feeder
cable 24 is provided between the masthead electronics 20 and the base
housing electronics 18. Accordingly, there are three feeder cables 24
illustrated in Figure 1. In traditional base station environments 10, each
antenna would be associated with one feeder cable 24.
[0017] Turning now to Figure 2, a block representation of the base housing
electronics 18 and one sector of the masthead electronics 20 is provided
according to one embodiment of the present invention. Notably, there are two
antennas 22 illustrated. A first antenna is referred to as a main antenna 22M,
and the second antennas is referred to as a diversity antenna 22D. For
signals transmitted from the main antenna 22M, a signal to be transmitted will
be provided over the feeder cable 24 to a duplexer 26 in the masthead
electronics 20. The signal to be transmitted (MAIN TX) is sent to another
duplexer 28 and transmitted via the main antenna 22M.
[0018] For receiving, signals transmitted from remote devices will be
received at both the main antenna 22M and the diversity antenna 22D. The
signals received at the main antenna 22M are referred to as the main receive
signals (MAIN RX), and the signals received at the diversity antenna 22D are
referred to as the diversity receive signals (DIVERSITY RX). In operation, the
main receive signal received at the main antenna 22M is routed by the
duplexer 28 to a low noise amplifier (LNA) 30, which will amplify the main
receive signal and present it to main frequency translation circuitry 32. The
main frequency translation circuitry 32 will effect a frequency translation,
which is essentially a shift of the main receive signal from being centered
about a first center frequency to being centered around a second center
frequency. The main frequency translation circuitry 32 may take the form of a
mixer, serrodyne, or the like, which is capable of shifting the center frequency
of the main receive signal.
[0019] Similarly, the diversity receive signal received at the diversity
antenna 22D may be filtered via a filter 34 and amplified using an LNA 36
before being presented to diversity frequency translation circuitry 38. The
diversity frequency translation circuitry 38 will effect a frequency translation of
the diversity receive signal from being centered about the first center
frequency to being centered about a third center frequency. Preferably, the
first, second, and third center frequencies are sufficiently different as to allow
signals being transmitted or received at those frequencies to be combined
without interfering with one another.
[0020] With reference to Figure 3, a graphical illustration of the frequency
translation process is provided. As illustrated, the main and diversity receive
signals are centered about the first center frequency /bi, wherein the
translated main receive signal is centered about center frequency fC2 and the
translated diversity receive signal is centered about center frequency The
center frequencies are sufficiently spaced along the frequency continuum to
avoid any interference between the signals transmitted on those center
frequencies.
[0021] Returning to Figure 2, the translated main receive signal and the
translated diversity receive signal provided by the main and diversity
frequency translation circuitries 32 and 38 are then combined with combining
circuitry 40 and presented to the duplexer 26. The duplexer 26 will then
transmit the composite signal to the base housing electronics 18.
[0022] The composite signal will be received by a duplexer 40 and
provided to separation circuitry 42, which will effectively separate the
translated main receive signal and the translated diversity receive signal and
provide them to main frequency translation circuitry 44 and diversity frequency
translation circuitry 46, respectively. The translated main and diversity
receive signals will be shifted back to being centered about the first center
frequency fa, which was originally used for transmitting the main and diversity
receive signals from the remote device. Accordingly, the main and diversity
receive signals are recovered by the main and diversity frequency translation
circuitries 44 and 46 and provided to transceiver circuitry 48, wherein the
receive signals are processed in traditional fashion and forwarded to a mobile
switching center (MSC) or other device via an MSC interface 50.
[0023] For transmitted signals, the base housing electronics 18 will
generate a main transmit signal (MAIN TX) using the transceiver circuitry 48
and provide the main transmit signal to a power amplifier (PA) 52. The
amplified main transmit signal will then be transmitted to the duplexer 40,
which will send the amplifier main transmit signal over the feeder cable 24
toward the masthead electronics 20, which will route the main transmit signal
to the main antenna 22M as described above.
[0024] The previous embodiment is configured to minimize the impact on
the existing transceiver circuitry 48 in the base housing electronics 18. In an
alternative embodiment, the translated main and diversity receive signals may
be presented directly to the transceiver circuitry 48, which may be modified to
be able to process the signals directly, instead of requiring them to be
translated back to being centered about their original center frequency, fa.
Further, the receive signals that are translated may be shifted up or down in
frequency to varying degrees. For example, the receive signals may be
shifted down to an intermediate frequency, to a very low intermediate
frequency, or to a near DC frequency, such as that used in Zero IF
architectures.
[0025] Although not shown, power may be fed from the base housing
electronics 18 to the masthead Electronics 20 via the antenna feeder. Power
would be coupled to the feeder cable 24 and off of the feeder cable 24 using a
conventional Bias-T as is typically done for masthead electronics 20.
Furthermore, a communication link between the base housing electronics 18
and masthead electronics 20 may also be desirable and implemented. The
communication link could be implemented at baseband or at an RF frequency
other than those frequencies of interest to the wireless operator, using a low
power RF transceiver.
[0026] Furthermore, if it is desirable to control the frequency translation to
a high level of precision, a local oscillator (LO) signal in the form of a sine
wave could be fed up the feeder cable 24 from the base housing electronics
18 and be extracted by the masthead electronics 20. The LO signal could be
a sine wave in the range of 100 to 200 MHz to facilitate separation from the
RX and TX signals.
[0027] Redundancy is often an issue for the masthead electronics 20. It is
therefore desirable that a minimum amount of functionality be maintained in
the event of a hardware failure with either the LNAs or frequency translation
circuitry. It would therefore be advantageous in both the main and diversity
receive paths be equipped with frequency translation circuitry. If one
frequency translation circuit 32 should fail, the main signal would pass through
the redundant circuitry unshifted and remain at its original frequency. In such
an event the main receive signal could propagate downwards to the base
housing electronics 18 at its original RF frequency and the diversity receive
signal would continue to be propagated as described.
[0028] Turning now to Figure 4, a second embodiment of the present
invention is illustrated. In this embodiment, the main receive signal is not
translated, while the diversity receive signal is translated. Thus, the main
receive signal and a translated diversity receive signal are combined in the
masthead electronics 20 and sent over the feeder cable 24 to the base
housing electronics 18. In particular, the main receive signal is received at
main antenna 22M, and forwarded to combining circuitry 40 via the duplexer
28, and through an LNA 30. The diversity receive signal is received at
diversity antenna 22D, filtered by the filter 34, amplified by the LNA 36, and
translated from the first center frequency /bi to a second center frequency fca
by the diversity frequency translation circuitry 38. The main receive signal
and the translated diversity receive signal are combined by combining circuitry
40 and sent to duplexer 26 for delivery to the base housing electronics 18
over the feeder cable 24. Upon receipt, the duplexer 40 at the base housing
electronics 18 will send a composite receive signal to the separation circuitry
42, which will provide the main receive signal to the transceiver circuitry 48,
and the translated diversity receive signal to the diversity frequency
translation circuitry 46, which will translate the translated diversity receive
signal back to being centered about center frequency /bi to effectively recover
the diversity receive signal, which is then provided to the transceiver circuitry
48 for processing. The main transmit signal is transmitted from the main
antenna 22M as described in association with Figure 2.
[0029] With reference to Figure 5, a graphical illustration of the translation
of the diversity receive signal is shown, as processed in the embodiment of
Figure 4. As illustrated, the translated diversity receive signal is shifted to be
centered about center frequency fe, wherein both the main and the original
diversity receive signals are centered about center frequency /bi-
[0030] If a masthead LNA is not desired or needed for the main receive
signal, the invention can be further simplified by removing the LNA 30 and
Duplexer 28 and combining circuitry 40. In such a case, both the transmit and
main receive signals can be fed directly to the duplexer 26, where they will be
combined with a translated diversity receive signal. The duplexer 26 would be
designed such that the main filter encompass both the main transmit and
main receive frequencies, and the other filter would encompass a shifted
diversity receive frequency. This implementation would provide a simpler and
less costly module while minimizing transmit path loss.
[0031] The advantages of this embodiment are twofold. Firstly, the main
receive path can be composed of only passive components, thereby
improving reliability. Alternatively, if an LNA 30 is desired at the masthead 16
for both the main and diversity receive signals, this embodiment remains
simpler since only the diversity receive frequency needs to be translated at
the mast, simplifying the electronics and frequency plan.
[0032] Turning now to Figure 6, a multi-band implementation of the present
invention is illustrated. A multi-band communication environment is one in
which the same or different cellular communication techniques are supported
by a base station environment 10. As illustrated, a single base housing 12 is
used, but different base housings 12 may be used for the different frequency
bands. In many instances, the different modes of communication, whether
incorporating the same or different underlying communication technologies,
are centered about different center frequencies. Two common frequencies
about which cellular communications are centered are 800 MHz and 1900
MHz. Accordingly, the base station environment 10 must be able to transmit
and receive signals at both 800 MHz and 1900 MHz, and may require
diversity antennas 22D to assist in receiving signals. In operation, received
signals in the 800 or 1900 MHz bands (BAND 1 and BAND 2, respectively)
may be received at diversity antenna 22D, wherein a duplexer 54 will send
800 MHz receive signals (800 RXD) through LNA 56 to BAND 1 frequency
translation circuitry 58, which will translate the 800 MHz receive signal about a
different center frequency. In this example, assume the BAND 1 frequency
translation circuitry downconverts the 800 MHz receive signal to a first
intermediate frequency (IF-i), wherein the downconverted signal is generally
referred to as 800 RXD @ IFi. Similarly, 1900 MHz receive signals (1900
RXD) will be provided through LNA 60 to BAND 2 frequency translation
circuitry 62, which will downconvert the 1900 MHz receive signal to a second
intermediate frequency (IF2), wherein the downconverted signal is
represented as 1900 RXD @ IF2.
[0033] The 800 RXD @ IFi and 1900 RXD @ IF2 signals are combined
using combining circuitry 64 to form a composite signal IFi + IF2, which is
provided to combining circuitry 26', which will combine the composite signal
IFi + IF2 with any signals received at the main antenna 22M, and in particular,
800 MHz and 1900 MHz receive signals (800 RX and 1900 RX). Thus, the
combining circuitry 26' may combine the 800 and 1900 MHz receive signals
with the composite IFi + IF2 signal and present them over the feeder cable 24
to separation circuitry 42 provided in the base housing electronics 18. The
separation circuitry 42 will provide the 800 and 1900 MHz signals to the
transceiver circuitry 48, as well as send the 800 RXD @ IF-i and 1900 RXD @
IF2 (translated) signals to respective BAND 1 and BAND 2 frequency
translation circuitry 66 and 68. The BAND 1 frequency translation circuitry 66
may upconvert the 800 RXD @ IFt signal to recover the original 800 RXD
signal, and the BAND 2 frequency translation circuitry 68 will process the
1900 RXD @ IF2 signal to recover the original 1900 RXD signal. The 800
RXD and 1900 RXD signals are then provided to the transceiver circuitry
for processing in traditional fashion. As noted for the previous embodiment,
the transceiver circuitry 48 may be modified to process the downconverted or
otherwise translated signals without requiring retranslations back to the
original center frequencies, as provided by the BAND 1 and BAND 2
frequency translation circuitry 66 and 68.
[0034] Accordingly, the present invention provides for translating signals
from one or more antennas 22 in a base station environment 10 in a manner
allowing the translated signals to be combined with one another and other
untranslated signals for transmission over a common antenna feeder 24. The
present invention is applicable to single and multi-band communication
environments, and is not limited to communication technologies or particular
operating frequencies. In general, the translation of received signals need
only operate such that when the signals are combined with other signals,
there is no interference or the interference is otherwise minimal or
manageable. Further, the receive signals may be from any spatially diverse
array of antennas for one or more sectors.
[0035] As noted, two base housings 12 that operate in different bands may
share the same feeder cables 24 and masthead 16.
[0036] Redundancy is a key issue for masthead electronics 20. Active
components which are used in the LNA 30 and frequency translation circuitry
32, 38 are less reliable than passive components used to implement the
duplexers 26, combining circuitry 40, and filters 34. As such, it may be
necessary to bypass the LNAs 30 within the module. An LNA bypass is
standard practice for masthead LNAs 30.
[0037] More important is redundancy in the frequency translation circuitry
32, 38. Since the objective is to transmit two receive signals, main and
diversity, down the same antenna feeder 24 to the base housing electronics
18, loss of the frequency translation function means that only one of the
receive signals can be relayed to the base housing electronics 18. It is
therefore important to consider redundancy schemes in practice.
[0038] One approach is to simply include multiple levels of redundancy
within each circuit block. A more sophisticated scheme would be to further
use frequency translation circuitry on both the main receive and diversity
receive signals as shown in Figure. 2. However, the frequency translation
circuitry 32, 38 should be designed as to allow a signal to pass through with
relatively little attenuation in the event of a hardware failure. Such would be
the case with a serrodyne implemented using exclusively shunt or reflection
type switches. The combining circuitry 40 could be designed to accept a
signal at the translated receive frequency or original receive frequency on
either port. The frequency translation circuitry 32, 38 would only be used in
one branch at any given time, and in the other branch the signal would be
passed through the frequency translation circuitry with little or no effect. In the
event that the active frequency translation circuitry 32, 38 should fail, the
unused frequency translation circuitry 32, 38 could be turned on to implement
the frequency translation on this branch, and the failed frequency translation
circuitry 32, 38 would then allow the signal to pass through untranslated.
[0039] Finally, in cases where four-branch receive diversity is used, it is
conceivable that each sector contain one transmit signal and four receive
signals. In such a case the present invention could easily be expanded to
translate the frequency of all receive signals or alternately on the three
diversity receive signals to separate frequencies and combine them all onto
one feeder cable 24 where they would be separated by another circuit at the
base station housing 12.
[0040] Those skilled in the art will recognize improvements and
modifications to the preferred embodiments of the present invention. All such
improvements and modifications are considered within the scope of the
concepts disclosed herein and the claims that follow.

Claims
What is claimed is:
1. A method for combining signals for transmission between masthead
electronics and base housing electronics in a base station
environment, the method comprising:
a) receiving a first receive signal centered about a first center
frequency from a first antenna;
b) receiving a second receive signal centered about the first center
frequency from a second antenna;
c) translating the first receive signal from the first antenna to being
centered about a second center frequency; and
d) combining the first receive signal centered about the second
center frequency and the second receive signal to form a
composite signal, which is sent to the base housing electronics
over a feeder cable.
2. The method of claim 1 wherein the first receive signal centered about
the second center frequency is combined with the second receive
signal centered about the first center frequency to form the composite
signal.
3. The method of claim 2 wherein the first center frequency and the
second center frequency are sufficiently spread to minimize
interference between the first and second receive signals in the
composite signal.
4. The method of claim 1 further comprising translating the second
receive signal from the second antenna to being centered about a third
center frequency, wherein the first receive signal centered about the
second center frequency is combined with the second receive signal
centered about the third center frequency to form the composite signal.
5. The method of claim 4 wherein the second center frequency and the
third center frequency are sufficiently spread to minimize interference
between the first and second receive signals in the composite signal.
6. The method of claim 1 wherein the second antenna is a main antenna
also used to transmit signals centered about the first center frequency
and the first antenna is a diversity antenna associated with the second
antenna, the method further comprising transmitting a transmit signal
via the main antenna.
7. The method of claim 1 wherein a plurality of receive signals, including
the second receive signal, are received and translated to being
centered about different center frequencies and combined to form the
composite signal.
8. The method of claim 1 further comprising:
a) separating the first and second receive signals from the composite
signal in the base station electronics; and
b) providing the first and second receive signals to transceiver
circuitry.
9. The method of claim 8 further comprising translating the first receive
signal to being centered about the first center frequency prior to
providing the first receive signal to the transceiver circuitry.
10. The method of claim 9 wherein the second receive signal is translated
to a third center frequency before being combined with the first receive
signal to form the composite signal, and further comprising translating
the second receive signal to being centered about the first center
frequency prior to providing the second receive signal to the
transceiver circuitry.
11. The method of claim 1 wherein the first and second receive signals
correspond to a cellular signal transmitted from a cellular
communication device.
12. The method of claim 1 wherein the first and second antennas are
associated with one of a plurality of sectors for the base station
environment.
13. The method of claim 12 wherein each sector uses one feeder cable
between the masthead electronics and the base housing electronics.
14. The method of claim 1 wherein the first center frequency is associated
with a first cellular band and a fourth center frequency is associated a
second cellular band, the method further comprising:
a) receiving a third receive signal centered about a third center
frequency from the first antenna;
b) receiving a fourth receive signal centered about the third center
frequency from the second antenna;
c) translating the third receive signal from the first antenna to being
centered about a fourth center frequency; and
d) combining the third receive signal centered about the third center
frequency and the second receive signal to form at least part of
the composite signal, which is sent to the base housing
electronics over the feeder cable.
15. The method of claim 14 further comprising translating the fourth
receive signal from the second antenna to being centered about the
fourth center frequency, wherein the third receive signal centered about
the fourth center frequency is combined with the fourth receive signal
centered about the fourth center frequency to form at least part of the
composite signal.
16. Base station electronics for combining signals for transmission
between a masthead and a base housing in a base station
environment, the base station electronics comprising in the masthead:
a) a first input adapted to receive a first receive signal centered
about a first center frequency from a first antenna;
b) a second input adapted to receive a second receive signal
centered about the first center frequency from a second antenna;
c) first translation circuitry adapted to translate the first receive signal
from the first antenna to being centered about a second center
frequency; and
d) combining circuitry adapted to combine the first receive signal
centered about the second center frequency and the second
receive signal to form a composite signal, which is sent to base
housing electronics over a feeder cable.
17. The base station electronics of claim 16 wherein the first receive signal
centered about the second center frequency is combined with the
second receive signal centered about the first center frequency to form
the composite signal.
18. The base station electronics of claim 17 wherein the first center
frequency and the second center frequency are sufficiently spread to
minimize interference between the first and second receive signals in
the composite signal.
19. The base station electronics of claim 16 further comprising second
translation circuitry adapted to translate the second receive signal from
the second antenna to being centered about a third center frequency,
wherein the first receive signal centered about the second center
frequency is combined with the second receive signal centered about
the third center frequency to form the composite signal.
20. The base station electronics of claim 19 wherein the second center
frequency and the third center frequency are sufficiently spread to
minimize interference between the first and second receive signals in
the composite signal.
21. The base station electronics of claim 16 wherein the second antenna is
a main antenna also used to transmit signals centered about the first
center frequency, and the first antenna is a diversity antenna
associated with the second antenna, the base station electronics
further comprising circuitry adapted to transmit a transmit signal via the
main antenna.
22. The base station electronics of claim 16 wherein a plurality of receive
signals, including the second receive signal, are received and
translated to being centered about different center frequencies and
combined to form the composite signal.
23. The base station electronics of claim 16 further comprising in the base
housing:
a) transceiver circuitry; and
b) separation circuitry adapted to separate the first and second
receive signals from the composite signal in the base station
electronics, wherein the first and second receive signals are
provided to transceiver circuitry.
24. The base station electronics of claim 23 further comprising, in the base
housing, second translation circuitry adapted to translate the first
receive signal to being centered about the first center frequency prior to
providing the first receive signal to the transceiver circuitry.
25. The base station electronics of claim 24 wherein the second receive
signal is translated to a third center frequency before being combined
with the first receive signal to form the composite signal, and further
comprising third translation circuitry adapted to translate the second
receive signal to being centered about the first center frequency prior to
providing the second receive signal to the transceiver circuitry.
26. The base station electronics of claim 16 wherein the first and second
receive signals correspond to a cellular signal transmitted from a
cellular communication device.
27. The base station electronics of claim 16 wherein the first and second
antennas are associated with one of a plurality of sectors for the base
station environment.
28. The base station electronics of claim 27 wherein each sector uses one
feeder cable between the masthead and the base housing.
29. The base station electronics of claim 16 wherein the first center
frequency is associated with a first cellular band and a fourth center
frequency is associated a second cellular band; a third receive signal
centered about a third center frequency is received via the first input
from the first antenna; a fourth receive signal centered about the third
center frequency is received via the second input from the second
antenna, the base station electronics in the masthead further
comprising second translation circuitry adapted to translate the third
receive signal from the first antenna to being centered about a fourth
center frequency, the combining circuitry further adapted to combine
the third receive signal centered about the third center frequency and
the second receive signal to form at least part of the composite signal,
which is send to the base housing over the feeder cable.
30. The base station electronics of claim 29 further comprising third
translation circuitry adapted to translate the fourth receive signal from
the second antenna to being centered about the fourth center
frequency, wherein the third receive signal centered about the fourth
center frequency is combined with the fourth receive signal centered
about the fourth center frequency to form at least part of the composite
signal.
31. A system for combining signals for transmission between masthead
electronics and base housing electronics in a base station
environment, the method comprising:
a) means for receiving a first receive signal centered about a first
center frequency from a first antenna;
b) means for receiving a second receive signal centered about the
first center frequency from a second antenna;
c) means for translating the first receive signal from the first antenna
to being centered about a second center frequency; and
d) means for combining the first receive signal centered about the
second center frequency and the second receive signal to form a
composite signal, which is sent to the base housing electronics
over a feeder cable.