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Claims  |
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We claim:
1. A wireless system for telephone communication within a building
comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one mobile wireless communication terminal adapted to receive
a predetermined one of the spread spectrum radio frequency signals within
the building and for demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signal from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signal to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central RF demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a central synchronization
and control circuit connected to all said interface means for receiving
supervisory signal from the junctors and/or a bus of the PABX and for
formulating polling and supervisory signal of predetermined format
received from the wireless communication terminal corresponding thereto
and for translating poll messages and supervisory signal of predefined
format to supervisory signal and for applying the latter signal to the
junctors and/or bus of the PABX, a supervisory channel spread spectrum
modulator using a predetermined supervisory channel correlation code for
receiving and spread spectrum modulating said formulated polling and
supervisory signal, RF modulating the latter signal and applying the RF
modulated signal via the transmit band limiting filter to the leaky
transmission line, a supervisory channel demodulator connected to the
output of the receive band limiting filter for RF demodulating and
despreading a received signal and applying received poll and supervisory
signals to the synchronization and control circuit.
2. A system as defined in claim 1 including means for transmitting a
supervisory signal on a fixed spread spectrum supervisory channel to said
wireless communication terminal, means at said terminal for receiving a
predetermined form of said supervisory signal designative of a particular
correlation code related to a receive channel, and means for correlating
the predetermined one of the spread spectrum signals using the correlation
code to effect said demodulation into said intelligible signal.
3. A system as defined in claim 1 including means at the central location
for receiving a signal at a particular port designative of a particular
junctor or channel of an incoming signal, and means for transmitting said
spread spectrum supervisory signal to said wireless terminal containing
said predetermined form of said supervisory signal designative of said
particular correlation code corresponding to said particular junctor or
channel.
4. A system as defined in claim 1 including means at the central location
for transmitting said spread spectrum communication signals to the
wireless communication terminals using pseudo-random spreading codes which
correspond to predetermined fixed correlation codes associated with
individual ones of the wireless communication terminals.
5. A system as defined in claim 1, in which each wireless communication
terminals is comprised of:
(i) a telephone set,
(ii) means for PCM encoding signals received from the telephone set,
(iii) means for spread spectrum and RF modulating the PCM encoded signals
using a first pseudo-random correlation code,
(iv) means for applying the RF modulated signals to an antenna through a
first filter for wireless transmission to the leaky transmission line,
(v) means for receiving RF and spread spectrum modulated signals from the
antenna via a second filter,
(vi) means for receiving RF and spread spectrum demodulating the received
signals using a second pseudo-random correlation code different from the
first correlation code,
(vii) means for PCM decoding the spread spectrum demodulated signals,
(viii) means for applying the PCM decoded signals to the telephone,
whereby wireless two-way communication via said leaky transmission line on
channels designated by the correlation codes is provided.
6. A system as defined in claim 5 in which the first and second correlation
codes are variable, and means for causing variation thereof whereby
particular designated send and receive spread spectrum channels are
established.
7. A system as defined in claim 6 including a synchronization and control
circuit, a second demodulator having its input connected to the output of
said second filter for receiving a supervisory signal including
synchronization signals, and providing demodulated digital supervisory
signals therefrom to the synchronization and control circuit, the second
demodulator using a fixed predetermined correlation code for demodulation
of the supervisory signals, a second modulator having its input connected
to the synchronization and control circuit for receiving supervisory
signals and spread spectrum modulating said latter signals using a fixed
predetermined pseudo-random code different from that of the correlation
code used in the first modulator, RF modulating these signals and applying
the signals via the second filter to the antenna, and means in the
synchronization and control circuit for receiving supervisory signals from
the telephone, generating supervisory data signals of predefined format
and applying them to the second modulator, and for receiving supervisory
data signals of predefined format from the second demodulator, for
translating said latter supervisory signals therefrom and applying said
translated signals to the telephone.
8. A system as defined in claim 7 including means at the synchronization
and control circuit for deriving designated correlation codes from the
received supervisory signals of predefined format and for enabling the
first modulator and demodulator to use said latter correlation codes in
modulation and demodulation respectively to establish the receive and
transmit channels for said signals.
9. A system as defined in claim 8 including means for generating and
displaying data at said wireless communication terminal, a data interface
circuit connected to said data generating and displaying means, third
means for spread spectrum and RF modulating data signals received via said
interface circuit and applying the RF modulated signals to the first
filter for transmission via the antenna to the leaky transmission line,
third demodulation means having its input connected to the antenna via the
second filter, and its output connected to the data interface circuit for
applying demodulated data signals thereto, and means connecting the third
modulator and demodulator to the synchronization and control circuit for
carrying signals therefrom designative of the pseudo-random correlation
codes to be used by the third modulator and demodulator.
10. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one wireless communication terminal adapted to receive a
predetermined one of the spread spectrum radio frequency signals and for
demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a central synchronization
and control circuit connected to all said interface means for receiving
supervisory signals from the junctors and/or a bus of the PABX and for
formulating polling and supervisory signals of predefined format
corresponding thereto and for translating poll messages and supervisory
signals of predefined format to supervisory signals and for applying the
latter signals to the junctors and/or bus of a the PABX, a supervisory
channel correlation code for receiving and spread spectrum modulating said
formulated polling and supervisory signals, RF modulating the latter
signal and applying the RF modulated signal via the transmit band limiting
filter to the leaky transmission line, a supervisory channel demodulator
connected to the output of the receive band limiting filter for RF
demodulating and despreading a received signal and applying received poll
and supervisory signals to the synchronization and control circuit, a
plurality of unidirectional repeaters connected serially at spaced
locations in the leaky transmission line whereby an input and an output to
the line are defined, the transmit filter being connected to the input of
the transmission line and the receive filter being connected to the output
of the transmission line.
11. A system as defined in claim 10, in which each wireless communication
terminal is comprised of:
(i) a telephone set,
(ii) means for PCM encoding signals received from the telephone set,
(iii) means for spread spectrum and RF modulating the PCM encoded signals
using a first pseudo-random correlation code,
(iv) means for applying the RF modulated signals to an antenna through a
first filter for wireless transmission to the leaky transmission line,
(v) means for RF and spread spectrum modulated signals from the antenna via
a second filter,
(vi) means for RF and spread spectrum demodulating the received signals
using a second pseudo-random correlation code different from the first
correlation code,
(vii) means for PCM decoding the spread spectrum demodulated signals,
(viii) means for applying the PCM decoded signals to the telephone,
whereby wireless two-way communication via said leaky transmission line on
channels designated by the correlation codes is provided.
12. A system as defined in claim 11 in which the first and second
correlation codes are variable, and means for causing variation thereof
whereby particular designated send and receive spread spectrum channels
are established.
13. A system as defined in claim 12 including a synchronization and control
circuit, a second demodulator having its input connected to the output of
said second filter for receiving a supervisory signal including
synchronization signals, and providing demodulated digital supervisory
signals therefrom to the synchronization and control circuit, the second
demodulator using a fixed predetermined correlation code for demodulation
of the supervisory signals, a second modulator having its input connected
to the synchronization and control circuit for receiving supervisory
signals and spread spectrum modulating said latter signals using a fixed
predetermined pseudo-random code different from that of the correlation
code used in the first modulator, RF modulating these signals and applying
the signals via the second filter to the antenna, and means in the
synchronization and control circuit for receiving supervisory signals from
the telephone, generating supervisory data signals of predefined format
and applying them to the second modulator, and for receiving supervisory
data signals of predefined format from the second demodulator, for
translating said latter supervisory signals therefrom and applying said
translated signals to the telephone.
14. A system as defined in claim 13 including means at the synchronization
and control circuit for deriving designated correleation codes from the
received supervisory signals of predefined format and for enabling the
first modulator and demodulator to use said latter correlation codes in
modulation and demodulation respectively to establish the receive and
transmit channels for said signals.
15. A system as defined in claim 14 including means for generating and
displaying data at said wireless communication terminal, a data interface
circuit connected to said data generating and displaying means, third
means for spread spectrum and RF modulating data signals received via said
interface circuit and applying the RF modulated signals to the first
filter for transmission via the antenna to the leaky transmission line,
third demodulation means having its input connected to the antenna via the
second filter, and its output connected to the data interface circuit for
applying demodulated data signals thereto, and means connected the third
modulator and demodulator to the synchronization and control circuit for
carrying signals therefrom designative of the pseudo-random correlation
codes to be used by the third modulator and demodulator.
16. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one mobile wireless communication terminal adapted to receive
a predetermined one of the spread spectrum radio frequency signals and for
demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a data interface circuit
connected to the former interface circuit for receiving and transmitting
data signals from and to the associated junctor and/or data bus of the
PABX, a data channel modulator having a fixed correlation code
corresponding to the junctor connected to the data interface circuit for
spread spectrum and RF modulating a data signal received therefrom and
applying the RF modulating signal via the transmit filter to the leaky
transmission line, a data channel demodulator having its input connected
via the receiver filter to the leaky transmission line, and for applying a
data signal to the data interface circuit for transmission to the junctor
or PABX data bus, a central synchronization and control circuit connected
to all said interface means for receiving supervisory signals from the
junctors and/or bus of the PABX and for formulating polling and
supervisory signals of predefined format received from the wireless
communication terminal corresponding thereto and for translating poll
messages and supervisory signals of predefined format to supervisory
signals and for applying the latter signals to the junctors and/or bus of
the PABX, a supervisory channel modulator using a predetermined
supervisory channel correlation code for receiving and spread spectrum
modulating said formulated polling and supervisory signals, RF modulating
the latter signal and applying the RF modulated signal via the transmit
band limiting filter to the leaky transmission line, a supervisory channel
demodulator connected to the output of the receive band limiting filter
for RF demodulating and despreading a received signal and applying
received poll and supervisory signals to the synchronization and control
circuit.
17. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one wireless communication terminal adapted to receive a
predetermined one of the spread spectrum radio frequency signals and for
demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a central synchronization
and control circuit connected to all said interface means for receiving
supervisory signals from the junctors and/or a bus of the PABX and for
formulating polling and supervisory signals of predetermined format
corresponding thereto and for translating poll messages and supervisory
signals of predefined format to supervisory signals and for applying the
latter signals to the junctors and/or bus of a the PABX, a supervisory
channel correlation code for receiving and spread spectrum modulating said
formulated polling and supervisory signals, RF modulating the latter
signal and applying the RF modulated signal via the transmit band limiting
filter to the leaky transmission line, a supervisory channel RF
demodulator connected to the output of the receive band demodulator
connected to the output of the receive bank limiting filter for RF
demodulating and despreading a received signal and applying received poll
and supervisory signals to the synchronization and control circuit, a
plurality of unidirectional repeaters connected serially at spaced
locations in the leaky transmission line whereby an input and an output to
the line are defined, the transmit filter being connected to the input of
the transmission line and the receive filter being connected to the output
of the transmission line, the frequency of the R.F. modulated signals
being between approximately 150 MHz and 1000 MHZ.
18. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one mobile wireless communication terminal adapted to receive
a predetermined one of the spread spectrum radio frequency signals and for
demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a central synchronization
and control circuit connected to all said interface means for receiving
supervisory signals from the junctors and/or a bus of the PABX and for
formulating polling and supervisory signals of predetermined format
corresponding thereto and for translating poll messages and supervisory
signals of predefined format to supervisory signals and for applying the
latter signals to the junctors and/or bus of a the PABX, a supervisory
channel correlation code for receiving and spread spectrum modulating said
formulated polling and supervisory signals, RF modulating the latter
signal and applying the RF modulated signal via the transmit band limiting
filter to the leaky transmission line, a supervisory channel demodulator
connected to the output of the receive band limiting filter for RF
demodulating and despreading a received signal and applying received poll
and supervisory signals to the synchronization and control circuit, a
plurality of unidirectional repeaters connected serially at spaced
locations in the leaky transmission line whereby an input and an output to
the line are defined, the transmit filter being connected to the input of
the transmission line and the receive filter being connected to the output
of the transmission line, the frequency of the RF modulated signals being
between approximately 150 MHz and 1000 MHZ, the transmission line being
coaxial cable having a shield containing gaps sufficient to allow RF
energy radiation therefrom.
19. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one mobile wireless communication terminal adapted to receive
a predetermined one of the spread spectrum radio frequency signals within
the building and for demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum modulating the encoded
signal and generating an RF modulated signal, means for applying the
latter RF modulated signal through a transmit band limiting filter to the
leaky transmission line, means for receiving an RF modulated signal from
the leaky transmission line through a receive band limiting filter, a
central demodulator for demodulating and despreading a received RF
modulated signal using a fixed pseudo-random correlation code associated
with said junctor for demodulating the latter signal, a PCM decoder for
receiving a spread spectrum demodulated signal and applying it to the
interface means for application to said junctor, a data interface circuit
connected to the former interface circuit for receiving and transmitting
data signals from and to the associated junctor and/or data bus of the
PABX, a data channel spectrum modulator having a fixed correlation code
corresponding to the junctor connected to the data interface circuit for
spread spectrum and RF modulating a data signal received therefrom and
applying the RF modulated signal via the receive band limiting filter to
the leaky transmission line, a data channel demodulator having its input
connected via the receive band limiting filter to the leaky transmission
line and for applying a data signal to the data interface circuit for
transmission to the junctor or PABX data bus, a central synchronization
and control circuit connected to all said interface means for receiving
supervisory signals from the junctors and/or a bus of the PABX and for
formulating polling and supervisory signals of predefined format
corresponding thereto and for translating poll messages and supervisory
signals of predefined format to supervisory signals and for applying the
latter signals to the junctors and/or bus of the PABX, a supervisory
channel modulator using a predetermined supervisory channel correlation
code for receiving and spread spectrum modulating said formulated polling
and supervisory signals, RF modulating the latter signal and applying the
RF modulated signal via the transmit band limiting filter to the leaky
transmission line, a supervisory channel demodulator connected to the
output of the receive band limiting filter for RF demodulating and
despreading a received signal, and applying received poll and supervisory
signals to the synchronization and control circuit, a plurality of
unidirectional repeaters connected serially at spaced locations in the
leaky transmission line whereby an input and an output to the line are
defined, the output of the transmit band limiting filter being connected
to the input of the transmission line and the input to the receive band
limiting filter being connected to the output of the transmission line.
20. A system as defined in claim 19, in which each wireless communication
terminal is comprised of:
(i) a telephone set,
(ii) means for PCM encoding signals received from the telephone set,
(iii) means for spread spectrum and RF modulating the PCM encoded signals
using a first pseudo-random correlation code,
(iv) means for applying the RF modulated signals to an antenna through a
first filter for wireless transmission to the leaky transmission line,
(v) means for receiving RF and spread spectrum modulated signals from the
antenna via a second filter,
(vi) means for RF and spread spectrum demodulating the received signals
using a second pseudo-random correlation code different from the first
correlation code,
(vii) means for PCM decoding the spread spectrum demodulated signals,
(viii) means for applying the PCM decoded signals to the telephone,
whereby wireless two-way communication via said leaky transmission line on
channels designated by the correlation codes is provided.
21. A system as defined in claim 20 in which the first and second
correlation codes are variable, and means for causing variation thereof
whereby particular designated send and receive spread spectrum channels
are established.
22. A system as defined in claim 21 including a synchronization and control
circuit, a second demodulator having its input connected to the output of
said second filter for receiving a supervisory signal including
synchronization signals, and providing demodulated digital supervisory
signals therefrom to the synchronization and control circuit, the second
demodulator using a fixed predetermined correlation code for demodulation
of the supervisory signals, a second modulator having its input connected
to the synchronization and control circuit for receiving supervisory
signals and spread spectrum modulating said latter signals using a fixed
predetermined pseudo-random code different from that of the correlation
code used in the first modulator, RF modulating signals and applying the
signals via the second filter to the antenna, and means in the
synchronization and control circuit for receiving supervisory signals from
the telephone, generating supervisory data signals of predefined format
and applying them to the second modulator, and for receiving supervisory
data signals of predefined format from the second demodulator, for
translating said latter supervisory signals therefrom and applying said
translated signals to the telephone.
23. A system as defined in claim 22 including means at the synchronization
and control circuit for deriving designated correlation codes from the
received supervisory signals of predefined format and for enabling the
first modulator and demodulator to use said latter correlation codes in
modulation and demodulation respectively to establish the receive and
transmit channels for said signals.
24. A system as defined in claim 23 including means for generating and
displaying data at said wireless communication terminal, a data interface
circuit connected to said data generating and displaying means, third
means for spread spectrum and RF modulating data signals received via said
interface circuit and applying the RF modulated signals to the first
filter for transmission via the antenna to the leaky transmission line,
third demodulation means having its input connected to the antenna via the
second filter, and its output connected to the data interface circuit for
applying demodulated data signals thereto, and means connected the third
modulator and demodulator to the synchronization and control circuit for
carrying signals therefrom designative of the pseudo-random correlation
codes to be used by the third modulator and demodulator.
25. A wireless communication system comprising:
(a) means at a central location for receiving a plurality of signals for
communication with selected wireless communication terminals,
(b) means at said central location for converting said signals to spread
spectrum radio frequency signals using correlation codes corresponding to
particular idle channels,
(c) a leaky transmission line located in a communication region within the
building,
(d) means for applying said spread spectrum radio frequency signals to said
transmission line for electromagnetic radiation within said region,
(e) at least one mobile wireless communication terminal adapted to receive
a predetermined one of the spread spectrum radio frequency signals within
the building and for demodulating it into an intelligible signal, and
(f) a plurality of similar circuits each comprising an interface means at
the central location for connection to an individual junctor of a PABX,
for receiving and transmitting communication signals from said junctor and
for receiving and transmitting supervisory signals from the PABX relating
to a telephone call, a central PCM encoder connected to the interface
means for receiving signals to be transmitted to a wireless communication
terminal, a modulator using a fixed pseudo-random correlation code
associated with the junctor for spread spectrum analog and generating an
RF modulated signal, means for applying the latter RF modulated signal
through a transmit band limiting filter to the leaky transmission line,
means for receiving an RF modulated signal from the leaky transmission
line through a receive band limiting filter, a central demodulator for
demodulating and despreading a received RF modulated signal using a fixed
pseudo-random correlation code associated with said junctor for
demodulating the latter si | | |
