U.S. patent application number 14/013739 was filed with the patent office on 2013-12-26 for spread-spectrum communication unit.
This patent application is currently assigned to INTERDIGITAL TECHNOLOGY CORPORATION. The applicant listed for this patent is INTERDIGITAL TECHNOLOGY CORPORATION. Invention is credited to Donald L. Schilling.
Application Number | 20130343286 14/013739 |
Document ID | / |
Family ID | 23021847 |
Filed Date | 2013-12-26 |
United States Patent
Application |
20130343286 |
Kind Code |
A1 |
Schilling; Donald L. |
December 26, 2013 |
SPREAD-SPECTRUM COMMUNICATION UNIT
Abstract
A set of spread-spectrum units is capable of operating as a base
station or as a remote unit. Each spread-spectrum unit includes a
base subunit or a remote subunit, each subunit having a receiver
for receiving spread-spectrum signals at a first frequency
transmitted from the spread-spectrum units; a signal despreader for
despreading the spread-spectrum; a demodulator for demodulating the
despread-spread-spectrum signals; a combiner for combining the
demodulated signals, and a local signal; a converter for converting
the combined signal to a base-data signal; a spread-spectrum
circuit for processing the base-data signal; and a transmitter for
transmitting at a second frequency the processed base-data signal
as a base-spread-spectrum signal.
Inventors: |
Schilling; Donald L.; (Sands
Point, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTERDIGITAL TECHNOLOGY CORPORATION |
Wilmington |
DE |
US |
|
|
Assignee: |
INTERDIGITAL TECHNOLOGY
CORPORATION
Wilmington
DE
|
Family ID: |
23021847 |
Appl. No.: |
14/013739 |
Filed: |
August 29, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12497973 |
Jul 6, 2009 |
8526327 |
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|
14013739 |
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|
11429386 |
May 5, 2006 |
7564808 |
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|
12497973 |
|
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|
09994290 |
Nov 26, 2001 |
7054278 |
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|
11429386 |
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|
09878647 |
Jun 11, 2001 |
6356534 |
|
|
09994290 |
|
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|
09133047 |
Aug 13, 1998 |
6295288 |
|
|
09878647 |
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|
08814809 |
Mar 10, 1997 |
5926465 |
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09133047 |
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08268186 |
Jun 29, 1994 |
5610906 |
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08814809 |
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Current U.S.
Class: |
370/328 |
Current CPC
Class: |
H04W 84/20 20130101;
H04M 3/56 20130101; H04B 1/707 20130101; H04W 72/005 20130101; H04B
1/7093 20130101; H04W 88/08 20130101; H04M 2207/18 20130101; H04W
88/06 20130101 |
Class at
Publication: |
370/328 |
International
Class: |
H04W 88/06 20060101
H04W088/06 |
Claims
1. A control device in a mobile communication unit comprising:
circuitry configured to enable the mobile communication unit to
operate in a first mode; wherein in the first mode, the mobile
communication unit receives first data from a first communication
unit and outputs the received data to a user of the mobile
communication unit; the circuitry is further configured to enable
the mobile communication unit to operate in a second mode; wherein
in the second mode, the mobile communication unit receives second
data from a second communication unit and transmits the received
second data to at least one of a plurality of third mobile
communication units; and the circuitry is further configured to
switch from the first mode to the second mode in response to an
input from the user of the mobile communication unit.
2. The control device in the mobile communication unit of claim 1
wherein the first communication unit and the second communication
unit are a same communication unit.
3. The control device in the mobile communication unit of claim 1
wherein the received data from the first communication unit is in a
code division multiple access signal.
4. The control device in the mobile communication unit of claim 1
wherein the received data from the first communication unit
includes voice data.
5. The control device in the mobile communication unit of claim 1
wherein the second data is transmitted at a same time to the at
least one of the plurality of third mobile communication units.
6. The control device in the mobile communication unit of claim 1
wherein in the second mode, the antenna and circuitry is configured
to broadcast data to the at least one of the plurality of third
stations.
7. The control device in the mobile communication unit of claim 9
wherein in the second mode, the circuitry is configured to further
output received data from the at least one second communication
unit to the user of the mobile communication unit.
8. A method of enabling a mobile communication unit using a control
device comprising: configuring the mobile communication unit to
operate in a first mode; wherein in the first mode, the mobile
communication unit receives first data from a first communication
unit and outputs the received data to a user of the mobile
communication unit; configuring the mobile communication unit to
operate in a second mode; wherein in the second mode, the mobile
communication unit receives second data from a second communication
unit and transmits the received second data to at least one of a
plurality of third mobile communication units; and switching from
the first mode to the second mode in response to an input from the
user of the mobile communication unit.
9. The method of claim 8 wherein the first communication unit and
the second communication unit are a same communication unit.
10. The method of claim 8 wherein the received data from the first
communication unit is in a code division multiple access
signal.
11. The method of claim 8 wherein the received data from the first
communication unit includes voice data.
12. The method of claim 8 wherein the second data is transmitted at
a same time to the at least one of the plurality of third mobile
communication units.
13. The method of claim 8 wherein in the second mode, the antenna
and circuitry is configured to broadcast data to the at least one
of the plurality of third stations.
14. The method of claim 8 wherein in the second mode, the circuitry
is configured to further output received data from the at least one
second communication unit to the user of the mobile communication
unit.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/497,973, filed on Jul. 6, 2009, which is a
continuation of U.S. patent application Ser. No. 11/429,386 filed
on May 5, 2006, which issued as U.S. Pat. No. 7,564,808 on Jul. 21,
2009, which is a continuation of U.S. patent application Ser. No.
09/994,290, filed on Nov. 26, 2001, which issued as U.S. Pat. No.
7,054,278 on May 30, 2006, which is a continuation of U.S. patent
application Ser. No. 09/878,647, filed on Jun. 11, 2001, which
issued as U.S. Pat. No. 6,356,534 on Mar. 12, 2002, which is a
continuation of U.S. patent application Ser. No. 09/133,047, filed
on Aug. 13, 1998, which issued as U.S. Pat. No. 6,295,288 on Sep.
25, 2001, which is a continuation of U.S. patent application Ser.
No. 08/814,809, filed on Mar. 10, 1997, which issued as U.S. Pat.
No. 5,926,465 on Jul. 20, 1999, which is a continuation of U.S.
patent application Ser. No. 08/268,186, filed on Jun. 29, 1994,
which issued as U.S. Pat. No. 5,610,906 on Mar. 11, 1997.
BACKGROUND
[0002] This invention relates to spread-spectrum communications,
and more particularly, to a method and system for handing off a
base station among a plurality of users in a spread-spectrum
network.
[0003] Spread-spectrum modulation is a well developed art, in terms
of generating chipping sequences, and spread-spectrum processing
data signals with the chipping sequences. Using this technology,
communication links may be established among a transmitter and a
receiver in remote locations. Also, networks may be established,
using a conference calling spread-spectrum technique. Conference
calling spread-spectrum techniques are disclosed in U.S. Pat. No.
5,179,572 entitled SPREAD SPECTRUM CONFERENCE CALLING SYSTEM AND
METHOD, to Schilling, and in U.S. Pat. No. 5,263,045, entitled
SPREAD SPECTRUM CONFERENCE CALL SYSTEM AND METHOD, to
Schilling.
[0004] A problem may exist where a spread-spectrum conference
calling system is set up, but the base station may need to change
hands. For example, in a military environment, a platoon may use
spread-spectrum modulation for conference calling among the members
of the platoon. A particular unit in the platoon may be designated
as the base station. The cited prior art does not teach how to
change a base station from one platoon to another or what would
happen among units in the platoon in the event it became necessary
to effectuate such a change.
SUMMARY
[0005] A communication unit comprises a command signal generator
for generating a command signal. A transmitter transmits
communication signals at one of two frequencies and for
transmitting the command signal. A receiver receives communication
signals at one of the two frequencies and for receiving the command
signal. Upon initiation of the command signal, the command signal
is transmitted for receipt by all active units in the system and
the unit transmitting the command signal receives communication
signals at a selected frequency of the two frequencies and
transmits communication signals at another frequency. Upon
reception of the command signal from another unit in the system,
the unit receiving the command signal transmits a communication
signal at the selected frequency of the two frequencies and
receives communication signals at the another frequency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate preferred
embodiments of the invention and together with the description
serve to explain the principles of the invention.
[0007] FIG. 1A is a block diagram of a base subunit using a
plurality of mixers;
[0008] FIG. 1B is a block diagram of a base subunit using a
plurality of matched filters;
[0009] FIG. 2A is a block diagram of a remote subunit using a
mixer;
[0010] FIG. 2B is a block diagram of a remote subunit using a
matched filter; and
[0011] FIG. 3 is a block diagram of a command subunit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Reference now is made in detail to the present preferred
embodiments of the invention, examples of which are illustrated in
the accompanying drawings, wherein like reference numerals indicate
like elements throughout the several views.
[0013] The present invention provides a unique solution to the
problem of a plurality of spread spectrum units in use in a mobile
environment in which any one of the spread-spectrum units is
vulnerable to neutralization while maintaining communication
between all the spread-spectrum units remains crucial. The
spread-spectrum changeable base station finds application in a
platoon of units, in an army environment, or in a law enforcement
application, where a transportable base station might be set up for
controlling a plurality of spread spectrum remote units. The
problem being addressed for each of these applications is what
happens when the base unit becomes disabled or nonfunctional. In
the military environment, the base station may be destroyed. In a
law enforcement situation, the mobility of the plurality of
spread-spectrum units may have a requirement that the base station
change from one unit to another.
[0014] The spread-spectrum system has a plurality of
spread-spectrum units, with each spread-spectrum unit having a base
subunit, a remote subunit, and a command subunit. The use of the
term "subunits" for designating the base subunit, remote subunit,
and command subunit, is for purposes of illustrating the invention.
The invention may be built as one totally integrated unit, or as a
mixture of more than one unit.
[0015] The base subunit is illustratively shown in FIGS. 1A and 1B.
The base subunit includes receiving means, despreading means,
demodulating means, combining means, converting means,
spread-spectrum processing means, and transmitting means. The
despreading means is coupled between the receiving means and the
demodulating means. The combining means is coupled to the
demodulating means and the converting means. The spread-spectrum
processing means is coupled to the converting means and the
transmitting means.
[0016] The receiving means is shown in FIG. 1A as antenna 11
coupled to radio frequency/intermediate frequency (RF/IF) amplifier
and filter section 12. The despreading means is illustrated as a
plurality of mixers 13, 14, 15. As shown in FIG. 1B, the
despreading means may also be embodied as a plurality of matched
filters 22, 23, 24. Each of the plurality of mixers 13, 14, 15 has
a chipping-sequence g.sub.1 (t), g.sub.2 (t), . . . , g.sub.N (t),
respectively, for mixing with the received spread-spectrum signal.
The plurality of chipping sequences is matched to the chipping
sequence of the desired spread-spectrum signal to be despread.
[0017] The demodulating means and combining means is shown as the
demodulator 16 and combiners 17A, 17B. Combiners 17A, 17B may be a
single combiner performing the combining function, or separate
combiners. The converting means is shown as an analog-to-digital
converter 18. The spread-spectrum processing means is illustrated
as product device 19, having a chipping sequence for spreading the
data signal from analog-to-digital converter 18. The transmitting
means is illustrated as transmitter 20 and antenna 21.
[0018] The RF/IF amplifier and filter circuits 12 are coupled to
the antenna 11 and to the plurality of mixers 13, 14, 15. The
plurality of mixers 13, 14, 15 is coupled to the demodulator 16 and
combiner 17A, 17B. The analog-to-digital converter 18 is coupled to
the combiner 17B and to the product device 19. The transmitter 20
is coupled to the product device 19 and to antenna 21. Antenna 21
and antenna 11 may be the same antenna with the appropriate
isolation circuits, or different antennas. The RF/IF amplifier and
filter circuits 12 receive at a first frequency, f.sub.1, a
plurality of spread-spectrum signals transmitted from the plurality
of spread-spectrum units. The plurality of spread-spectrum signals
are despread by the plurality of mixers 13, 14, 15. As shown in
FIG. 1B, the despreading means may also be embodied as a plurality
of matched filters 22, 23, 24. The output of the plurality of
mixers 13, 14, 15 is a plurality of despread-spread-spectrum
signals. The demodulator 16 demodulates the plurality of
despread-spread-spectrum signals to generate a plurality of
demodulated signals. The combiner 17A combines the plurality of
demodulated signals. The combined plurality of demodulated signals
and a local signal from the base station may be combined by second
combiner 17B to generate a combined signal. The term "combined
signal", as used herein, is an analog signal including the voice of
the base station and the combined demodulated signals of the
combiners 17A, 17B.
[0019] The combined signal is converted to a base-data signal by
analog-to-digital converter 18. The term "base-data signal," as
used herein, is the digital signal coming from the
analog-to-digital converter 18, and includes the converted analog
signals and the data signal at the base station.
[0020] The product device 19 spread-spectrum processes the
base-data signal from analog-to-digital converter 18, with a
base-chipping sequence. The spread-spectrum-processed-base-data
signal is transmitted as a base-spread-spectrum signal by
transmitter 20 at the second frequency f.sub.2. Antenna 11 and
antenna 21 may be a single antenna, serving both the receiver and
transmitter.
[0021] The remote subunit is illustrated in FIGS. 2A and 2B and
includes a receiver portion, a transmitter portion, receiving
means, despreading means, and demodulating means. The transmitting
portion includes converting means, spread-spectrum processing means
and transmitting means. The receiving means receives at the second
frequency the base-spread-spectrum signal. The despreading means
despreads the base-spread-spectrum signal as a
despread-base-spread-spectrum signal. The demodulating means
demodulates the despread-base-spread-spectrum signal as a
base-analog signal.
[0022] The converting means converts a remote-analog signal to a
remote-data signal. The remote-analog signal typically is the voice
of the remote station. The base-analog signal typically is the
plurality of voice signals from the base station. The
spread-spectrum processing means processes the remote-data signal
with a remote-chipping sequence. The transmitting means transmits
at the first frequency the spread-spectrum-processed-remote-data
signal as one of the plurality of spread-spectrum signals, which
are received at the base subunit.
[0023] As shown in FIG. 2A, the receiving means includes an antenna
31 and RF/IF amplifier and filter circuitry 32. The despreading
means and demodulating means are embodied as mixer 33 and
demodulator 34, respectively. As shown in FIG. 2B, the despreading
means may also be embodied as a matched filter 39. The RF/IF
amplifier and circuitry 32 is coupled between antenna 31 and the
mixer 33. The demodulator 34 is coupled to the mixer 33.
[0024] The base-spread-spectrum signal at antenna 31 is amplified
and filtered by RF/IF. The base-spread-spectrum signal is despread
by the base-chipping sequence by mixer 33 to generate the
despread-base-spread-spectrum signal. The demodulator 34
demodulates the despread-base-spread-spectrum signal as a
base-analog signal. The output of the demodulator 34 is the
plurality of voice signals from the base station.
[0025] The transmitter section of the remote subunit may have the
converting means embodied as analog-to-digital converter 35, the
spread-spectrum processing means embodied as product device 36 and
the transmitting means embodied as transmitter 37 coupled to
antenna 38. The product device 36 is coupled between the
analog-to-digital converter 35 and the transmitter 37.
[0026] The analog-to-digital converter 35 converts the voice of the
remote signal, designated here as the remote-analog signal, to a
remote-data signal. The remote-data signal is spread-spectrum
processed by the product device 36 using remote-chipping sequence.
The output of the product device 36 is the
spread-spectrum-processed-remote-data signal. The transmitter 37
transmits the spread-spectrum-processed-remote-data signal using
antenna 38, as one of the plurality of spread-spectrum signals.
Antenna 31 and antenna 38 may be combined as a single antenna
serving both functions.
[0027] The command subunit is illustrated in FIG. 3. The command
subunit includes initiating means, broadcasting means, and
receiving means. The initiating means initiates a command signal,
upon activation by the local user of that spread-spectrum unit. The
command signal activates the base subunit in that spread-spectrum
unit. The broadcasting means broadcasts the command signal to the
plurality of spread-spectrum units. The receiving means receives
the command signal when broadcast from a different spread-spectrum
unit. The activating means activates the remote subunit upon
receiving the command signal.
[0028] The initiating means is illustrated in FIG. 3 as a push
button switch 43. The broadcasting means is illustrated as a
transmitter portion of the transmitter/receiver 42. The transmitter
transmits at frequency f.sub.3. The receiving means is illustrated
as the receiver portion of transmitter/receiver 42. The receiver
receives at frequency f.sub.3. The transmitter/receiver 42 is
coupled to antenna 41 for radiating and receiving signals. The
activating means includes the necessary circuitry for disconnecting
the base subunit and activating the remote subunit of a particular
spread-spectrum unit. The activating means is illustrated as
control circuitry 44. The present invention may also be used for
data in place of voice signals.
[0029] In use, a particular spread-spectrum unit might be operating
with its remote subunit activated. Thus, the remote subunit of that
particular spread-spectrum unit receives at the second frequency
the base-spread-spectrum signal, and despreads the
base-spread-spectrum signal as a despread-base-spread-spectrum
signal. The despread-base-spread-spectrum signal is demodulated.
Thus, that particular spread-spectrum unit receives all of the base
signals via its remote subunit. While transmitting to the plurality
of spread-spectrum units, that particular spread-spectrum unit
converts the voice signal, embodied as the remote-analog signal, to
the remote-data signal. The remote-data signal is spread-spectrum
processed and transmitted at the first frequency as one of the
plurality of spread-spectrum signals.
[0030] Upon initiation of the command signal by the user of that
particular spread-spectrum unit, by pushing push button 43, that
particular spread-spectrum unit switches from operating with the
remote subunit to operating with the base subunit. At the same
time, the command signal is radiated to the other spread-spectrum
units of the plurality of spread-spectrum units. Upon receiving the
command signal, each of the spread-spectrum units has its remote
subunit activated and thereafter works in a remote subunit mode.
The particular spread-spectrum unit has then become the base
station.
[0031] When operating as the base station, the particular
spread-spectrum unit has its base subunit activated. Accordingly,
the plurality of spread-spectrum signals transmitted from the
plurality of spread-spectrum units at each unit, is received by the
RF/IF amplifier and circuitry 12 via antenna 11. The plurality of
spread-spectrum signals are despread by the plurality of mixers 13,
14, 15, and demodulated by the demodulator 16 which outputs a
demodulated signal. The plurality of demodulated signals from
combiner 17A are the voices from the plurality of remote stations.
The voices from the plurality of remote stations are combined with
the voice of the base station by combiner 17B, and converted by
analog-to-digital converter 18 to the base-data signal. The
base-data signal is spread-spectrum processed by the product device
19 and transmitted by transmitter 20 and via antenna 21 at the
second frequency.
[0032] As will be appreciated by those of ordinary skill in the
art, an example of the spread spectrum unit built as a totally
integrated unit referenced in paragraph [0019] above is a
combination of the command subunit of FIG. 3 with a base subunit of
FIG. 1A or 1B and a remote subunit of FIG. 2A or 2B where the
command subunit antenna 41 serves as both the transmit and receive
antenna for both the base and remote subunits. Such a combination
is an example of a mobile communication unit that has an antenna
and circuitry configured in a first mode as a remote subunit and in
a second mode as a base subunit. Such a mobile communication unit
in the first mode will receive data from a first communication unit
such as voices from a base station and output the base station
voices to a user of the mobile communication unit as described in
connection with FIGS. 2A and 2B. Such a mobile communication unit
in the second mode will receive data from a communication unit such
as a voice from at least one remote station and will transmit the
received data to a plurality of mobile communication units, i.e.
remote subunits, as described in connection with FIGS. 1A and 1B.
The command subunit of such a mobile communication unit permits it
to switch from the first mode to the second mode in response to an
input from a user of the mobile communication unit, such as via
switch 43. Accordingly, switch 43 permits a user of the mobile
communication unit to switch between the first mode and the second
mode in response to the user switching the switch that then serves
as an input to the command subunit. It thus follows that, on a
condition that the mobile communication unit is in the first mode,
data is received from a first communication unit and output to the
user of the mobile communication unit. It further follows that, on
a condition that the mobile communication unit is in the second
mode, data is received data from at least one second communication
unit and transmitted data to a plurality of third mobile
communication units, i.e. remote subunits.
* * * * *