Note: Descriptions are shown in the official language in which they were submitted.
CA 02713475 2010-08-18
SYSTEM AND METHOD FOR SIGNAL RECEPTION AND DISTRIBUTION
TECHNICAL FIELD
[00011 The present application generally relates to a system and method for a
signal
reception and distribution.
TECHNICAL BACKGROUND
[00021 Audio/video content can be broadcasted via an over-the-air signal. The
content
may be captured with an antenna and displayed on a display device such as a
television.
The over-the-air carrier signal typically comprises signal information
associated with a
plurality of separate channels each modulated to a distinct frequency. A tuner
is used to
isolate information from a single channel within the broadcast signal. In the
case of a
tuner external to the display device (for example, a "set top box" or STB),
the signal
information is processed (for example modulated to a particular frequency),
and the
external tuner outputs an. audio/video stream of which the video component is
displayed
on the television and the audio component is played through an internal or
external
amplifier.
[00031 Antennas for receiving over-the-air signals are conventionally mounted
in
elevated locations and preferably outdoors in order to maximize the signal
strength and
thus the quality of the signal. Antennas which are placed indoors on a ground
floor or in a
basement, for example in a home or business, typically receive a lower quality
(i.e. low
strength) over-the-air signal, and the outputted audio/video stream
transmitted to the
receiving device is of commensurately poor quality. However, in order to
connect an
antenna mounted in an elevated location and/or outdoors with receiving devices
such as
televisions located within the premises on the ground floor or in the
basement, long
stretches of wiring is needed. The wiring used is not aesthetically appealing,
and it can be
difficult to conceal the wiring from view. Locating such wiring in a way that
does not
interfere with normal use of the premises can result in an unsightly and
convoluted path
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about the structure. Additionally, long stretches of wiring and multiple
connections may
cause signal degradation. Other challenges associated with antennas include
geographic
spacing of signal sources and optimization for a particular frequency range
(for example,
either UHF or VHF).
100041 It would be advantageous to provide a system where antenna for
receiving an
over-the-air audio/video signal could be placed in a location where signal
reception is
maximized but long stretches of unattractive wiring to connect the antenna to
a receiving
device is not required. Instead, content could be delivered over an existing
network, such
as a wireless network, a wired network, a LAN, a WAN, or the like. It would
also be
advantageous to provide a system to reduce signal loss or degradation due to
attenuation
between the antenna and the tuner by reducing the physical distance between
said
components. It would also be advantageous to provide a system for distributing
content
received from an over-the-air audio/video signal to a plurality of receiving
devices. It
would also be advantageous to provide a system with a plurality of means for
receiving
over-the-air signals, wherein the system provides for `smart' switching
between antennas
based on signal frequency, direction of the signal, signal-to-noise ratio
(SNR), packet
error rate (PER), bit error rate (BER), gain, and multi-path detection.
BRIEF DESCRIPTION OF THE DRAWINGS
[00051 In drawings which illustrate by way of example only a preferred
embodiment of
the invention,
[00061 FIG. 1 is a block diagram of a client device and a server according to
the
invention.
[00071 FIG. 2 is a block diagram of a client device according to the
invention.
[00081 FIG. 3 is a block diagram of a signal reception and distribution system
according
to the invention.
[00091 FIG. 4 is a flowchart of a process for displaying video on a client
device.
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[00101 FIG. 5 is a flowchart of a process for initializing a signal reception
and
distribution system in a system according to the invention.
[00111 FIG. 6 is a flowchart of a process for retrieving and displaying
electronic
programming information on a client device.
[00121 FIG. 7 is a flowchart of a process for changing the channel to be
displayed on a
client device.
[00131 FIG. 8 is a flowchart of a process for producing a network transport
stream from
an over-the-air signal.
100141 FIG. 9 is a block diagram of a further embodiment of a signal reception
and
distribution system according to the invention.
10015] FIG. 10 is a schematic representation of an electronic programming
guide.
[0016] FIG. 11 is a circuit diagram of a passive line coupling unit.
[00171 FIG. 12 is a block diagram of a further embodiment of a signal
reception and
distribution system according to the invention.
DETAILED DESCRIPTION
[00181 The invention provides a system and method for receiving and
distributing an
over-the-air audio/video signal. The particular embodiments described herein
provide a
system and method for receiving an over-the-air signal, retrieving audio/video
information from the signal, and processing the information for distribution
over a
network. The invention will be described primarily in relation to receiving
devices
comprising client devices 100 (marked as 100-1, 100-2... 100-n), and an
associated
server 120, as illustrated in FIGS. 1 and 2. It will be appreciated by those
skilled in the art
that client devices may include (without limitation) desktop computers,
terminals,
laptops, tablets, cellular phones, smartphones, wireless organizers, personal
digital
assistants, handheld wireless communication devices, wirelessly-enabled
notebook
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computers, television receivers and the like. A server 120 includes (without
limitation)
any system capable of exchanging messages with client devices 100. It will
also be
appreciated that the system of the invention may receive signals from other
sources in
addition to over-the-air broadcasts.
[00191 FIG. 1 is a block diagram showing a plurality of client devices 100 and
server
120. Client devices 100 may communicate with server 120 via any suitable wired
or
wireless communications medium 110, for example including but not limited to a
Local
Area Network (LAN), a Wide Area Network (WAN) including the Internet, a
wireless
network, and others. Server 120 may comprise, or may be in communication with,
a data
store 130. Server 120 may store data in and retrieve data from the data store
130.
100201 The data store 130 may be local or remote with respect to server 120.
The data
store 130 may comprise a database or some other programming construct. For
example,
the data store 130 may comprise a single relational database or a plurality of
databases.
[00211 FIG. 2 is a block diagram of an embodiment of a client device 100 for
the system
of the invention. Client device 100 may comprise processing unit 200, for
example a
microcontroller, Random Access Memory (RAM) 210, a display 220, a storage
device
230, a communications subsystem 240, and an input interface 250. The
processing unit
200 controls the overall operation of the client device 100. The RAM 210 is a
volatile
store which provides for temporary storage of data. The communications
subsystem 240
allows client device 100 to communicate with other devices, for example with
server 120
either directly or over a network. Storage device 230 maybe used to store an
operating
system and software components, and preferably comprises a persistent store
such as
flash memory. Input interfaces may include a remote control, a keyboard, a
mouse, or any
other suitable means for inputting data, including commands.
[0022] FIG. 3 illustrates a block diagram of a system for receiving an `over-
the-air' (also
sometimes known as `on-the-air' or `off-air') signal and distributing selected
content of
the received signal over a network. The system comprises at least one means
for detecting
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and receiving over-the-air signals comprising video and/or audio content. In
the
embodiment illustrated in FIG. 3, the system comprises a variety of sources
from which
to obtain a signal, including a plurality of antennas, in some embodiments
including a line
coupling unit ("LCU") 317 and baseband inputs such as composite, component,
HDMI,
USB and other baseband inputs 323, coaxial cable 316 from a CATV service,
fractal
panel array 318, an external input 315, and data inputs 324, such as Ethernet,
USB, WiFi,
etc. In this embodiment, the plurality of antennas 312, fractal panel array
318, and LCU
317 are configured to detect and receive over-the-air signals comprising video
and/or
audio content (with or without ancillary content, for example closed-
captioning data,
electronic programming guide (EPG) data, etc.) from at least one transmitter
(not shown).
Typically different video and audio content is encoded on different channels
of the
transmitted signal. The plurality of antennas 312 may be, for example, an
antenna array.
[0023] In the embodiment shown, in which a plurality of sources from which to
obtain a
signal are provided, a signal selector 305 communicates with signal switch 319
to
determine the source from which a signal is obtained. Signal selector 305
receives
feedback from tuner 306 and demodulator 307 to determine whether a different
source
ought to be selected. Upon determining that a different source ought to be
selected, signal
selector 305 instructs signal switch 319 to select that source.
[00241 Signal selector 305 may be in constant or intermittent communication
with the
plurality of signal sources, including the plurality of antennas, in order to
continually
optimize signal quality. The quality of the signal obtained from each of the
sources may
vary with time, depending on various external factors. In the event that a
selected source
no longer provides the best signal amongst the available sources, a different
source may
be selected when it is detected that the source provides a better signal. For
example, in
this embodiment the signal selector 305 intermittently, at selected intervals,
tests the
signal characteristics (e.g. gain at the selected frequency) obtainable from
each of the
plurality of antennas and preferably other sources fed through the signal
selector 305, and
may optionally analyze the amount of multipath propagation or signal
interference
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detected, PER, BER, SNR, gain, resolution, data density, signal quality, and
other
parameters. The feedback maybe obtained from the tuner 306 and/or demodulator
307.
The signal selector 305 may then select or reject signals from the different
sources based,
for example, on the amount of multipath propagation or signal interference
detected,
PER, BER, SNR, gain, resolution, data density, signal quality, and other
parameters.
Once signal selector 305 selects a source from which to obtain a signal,
signal switch 319
provides the signal from the selected source to server 310. The signal
selector 305 may
select more than one source from the plurality of signal sources for
processing in the
embodiment with multiple tuners. In the embodiment with multiple tuners,
multiple
demodulators (or multi channel demodulators) and multiple transcoders are
employed.
[00251 In the embodiment where only a single source for obtaining signal
information is
provided, signal selector 305 and signal switch 319 are unnecessary.
[00261 In the embodiment shown in FIG. 3, a variety of sources may be used to
obtain
audio/video signals, including: a line coupling unit 317 ("LCU"), a fractal
panel array
318, a plurality of antennas 312, one or more independent antennas 301, a
cable television
line 316, or some other external input 315. External input 315 maybe, for
example, a
satellite, an outdoor antenna, a video server, a set top box, wireless 3G/4G,
or some other
external input. In this embodiment, a signal switch 319 is provided for
switching between
the inputs. Signal switch 319 maybe a `many to many' switch, capable of
receiving
multiple inputs and outputting multiple outputs. In this example, signal
switch 319 is
capable of outputting signals to multiple servers 310. Each server 310 may
receive a
signal from a single source, or they may receive signals from multiple
sources.
[00271 In a further embodiment (not shown), server 310 may comprise one or
more
means for detecting an over-the-air signal, including but not limited to a
plurality of
antennas 312, one or more independent antennas 301, a LCU 317, and a fractal
panel
array 318. In this embodiment, the signal selector 305 selects one means for
detecting an
over-the-air signal. Output from the selected means is sent to tuner 306.
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100281 Each of the antennas 301 may comprise a fractal printed circuit board
antennas or
polymer strip line directional antennas, which are known to those skilled in
the art. Those
skilled in the art will appreciate that any antennas suitable for receiving an
over-the-air
audio/video signal may be used in a system of the invention. Those skilled in
the art will
also appreciate that antenna 301 may be adapted to receive any RF input. A
fractal
element antenna ("FEA") is one that has been shaped in a fractal fashion,
either through
bending or shaping a volume, or introducing holes. They are based on fractal
shapes such
as the Sierpinski triangle, Mandelbrot tree, Koch curve, and Koch island. The
advantage
of a fractal element antenna, as compared to a conventional antenna design, is
that they
are typically more compact and provide wider bandwidth.
100291 The home wiring antenna comprising Line Coupling Unit (LCU) 317 is
preferably
capacitively-coupled to the carrier current in the premises' electrical
wiring, telephone
wiring or any other communications wiring within a wired network, internal or
external
to a building or enclosure (although the connection to the carrier current may
alternatively
be inductive). While LCU 317 is advantageously coupled to a home wiring
antenna, it
may also be coupled with other antenna types.
[0030] FIG. 11 is a circuit diagram of a passive LCU. In a passive LCU, the
capacitance
and the resistance are fixed. LCU 317 is preferably an active unit comprising
a micro
controller 320, a resistance-capacitance coupler 321 ("RC coupler"), and at
least one
input/output interface 322. Advantageously, the LCU 317 matches impedance on a
frequency-by-frequency basis. This is possible because the LCU 317 is coupled
directly
onto an AC circuit in the premises (for example, a circuit from the mains
power supply)
in order to ensure that an accurate impedance is provided to the LCU 317,
which is
critical to obtaining maximum gain. The micro controller 320 may be provided
when
coupling onto a line where the impedance may change due to load (current),
circuit
length, and/or devices connected at other network terminations. The micro
controller 320
communicates with the server 310 to receive channel selection and frequency
information, and based on the information received, controls the RC coupler
321 to
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change the value in the resistance load in a resistance-capacitance circuit to
match the
impedance best suited at the frequency selected. The RC coupler 321 may
comprise, for
example, a high pass filter. The micro controller 320 maybe dedicated to the
LCU 317,
or it may be provided as part of demodulator 307 or transcoder 308 and in
communication
with the LCU 317. Input/output interface 322 may be USB, Ethernet, or a
general purpose
input/output. The general purpose input/output, Ethernet, and USB connections
may be
used to communicate with the micro controller 320 to program, read, write,
download
upload data. This maybe used to set up or control the LCU 317. The LCU 317 is
communicating with the signal selector/tuner/demodulator to optimize the RC
coupling,
adjusting the impedance based on tuner 306/demodulator 307 feedback. In order
to
accurately match impedance, the server 310 is connected to the LCU. When the
line
impedance has been accurately matched, the RC coupler 321 compensates
accordingly to
achieve the maximum gain.
[0031] In the embodiment shown in FIG.3, server 310 comprises a signal
selector 305, a
tuner 306, a demodulator 307, a transcoder 308, and a communications interface
309.
Once the signal switch 319 selects a source from which to obtain a signal,
signal switch
319 outputs the signal from the selected source to the server 310 via
communications
medium 314. Signal switch 319 is preferably a multiple input, multiple output
device.
Tuner 306 of server 310 processes the output from signal switch 319 by
changing the
signal to an intermodulated frequency. By changing the signal to an
intermodulated
frequency, typically down to baseband so that a baseband demodulator can be
used for
more efficient processing at that frequency, as is known to those skilled in
the art. Output
from baseband inputs 323 may be delivered to server 310 via communications
medium
325. Output from baseband inputs 323 maybe provided to the transcoder 308 for
transcoding. Output from data inputs 324 may be delivered to server 310 via
communications medium 326. Output from the data inputs 324 may be provided to
the
communications interface 309 for redistribution throughout the network.
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[0032] Server 310 maybe co-located with the plurality of antennas 312, or it
maybe
remote from the plurality of antennas 312. By placing server 310 in close
proximity with
the plurality of antennas 312, signal loss may be minimized. However, in some
scenarios
it may be desirable to place the plurality of antennas 312 remote from the
server 310, as
the server 310 may not be in a location which provides maximum reception.
[0033] In another embodiment, server 310 may itself comprise an antenna 301.
In this
embodiment, output from antenna 301 maybe sent to tuner 306.
[0034] The output from the selected means for providing a signal comprises
many
channels. Tuner 306 is configured to isolate the portion of the output which
is associated
with a selected channel (i.e. a frequency), producing an intermodulated
carrier wave
which carries the data associated with the selected channel. Signal quality
parameters
such as PER, BER, SNR, gain, signal stren , and multi-path detection are
obtained
from the tuner and demodulator and are compared by a lookup table in order to
determine and select the best signal and send the instruction to the signal
switch 319 to
select the appropriate antenna. The system will preferably constantly or
intermittently
monitor the output to reduce multipath and ghosting. In one embodiment, tuner
306 is
configured to receive a vestigial side band (8VSB) signal, for example as
defined in the
Advanced Televisions Systems Committee (ATSC) standards. 8VSB is the current
standard by which television signals are transmitted over the air. Those
skilled in the art
will appreciate that other standards may be used to transmit television
signals and that
tuner 306 maybe configured to work with any such standards.
[0035] For example, tuner 306 maybe configured to receive a Quadrature
Amplitude
Modulation (QAM) signal, which is the current standard used for delivering a
television
signal over coaxial cable. In this embodiment, server 310 may be provided with
a means
adapted to receive a signal from coaxial cable (not shown). In this way,
server 310 maybe
used to receive both over-the-air signals and cable signals.
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[00361 Ina further embodiment, server 310 comprises more than one tuner 306.
The
function of a tuner 306 is to isolate from an over-the-air signal a modulated
carrier wave
for a selected channel within the over-the-air signal. With a single tuner
306, server 310
would only be able to distribute a video stream for a single channel. By
providing for
additional tuners 306 in the server 310, a first client device 100-1 may
request a first
channel while additional client devices 100-2, 100-3 through 100-N may request
different
channels. In this embodiment, each tuner 306 has an associated demodulator 307
and
transcoder 308 operating in accordance with the invention.
[0037] Tuner 306 produces an intermodulated carrier wave associated with the
selected
channel and outputs the carrier wave to demodulator 307. Demodulator 307 is
configured
to demodulate the intermodulated carrier wave. Demodulator 307 extracts the
information
from the tuner output signal and encodes the information into a first format,
for example a
digital video format. Techniques for demodulation to extract information from
an
intermodulated carrier wave are well known to those skilled in the art.
[00381 In one embodiment, demodulator 307 may convert information recovered
from
the tuner output signal to an MPEG2 format, which is a current standard for
the generic
coding of moving pictures and associated audio information. The resulting data
stream in
this first signal format may then output to transcoder 308.
[0039] Transcoder 308 receives the output from demodulator 307 and encodes the
demodulator output into a data stream in a second format. The demodulator
output may
for example be encoded into a second video format. The second video format
maybe in a
standard format such as MPEG4 (H.264). In this embodiment, the output from
demodulator 307 is transcoded by the transcoder 308, resulting in a transport
stream that
requires less bandwidth for distribution over the network.
[00401 Ina further embodiment, a data stream in a second video format maybe
produced
'directly from the information extracted from the demodulator 307 output
signal.
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[00411 The data stream in a second format (either output from transcoder 308
or
extracted directly from the demodulator 307 output signal) is packaged in a
format
suitable for transport over the network by communications interface 309 or
some other
suitable processing means to produce a network transport stream, as is well
known.
Communications interface 309 may send the network transport stream to other
members
of a network (not shown) via communications medium 110. The network transport
stream
may be in any suitable network protocol. For example, the network transport
stream may
be in the Transmission Control Protocol/Internet Protocol (TCP/IP) format.
Communications medium 110 may be wired, or wireless.
[00421 FIG. 4 illustrates a method for initiating a signal distribution system
according to
the invention. In this embodiment, client device 100 initiates a viewer
application at 401.
Viewer application may be a browser, a widget, a browser plug-in, or some
other program
construct for rendering video. The viewer application initiates a search for
the server 120
over a network at 402. If more than one server 120 is located, the viewer
application may
connect to a default server 120 (if defined) or the user maybe asked to select
a preferred
server 120. To connect with server 120, client device 100 initiates a request
to be
registered with server 120 at 403. Server 120, receiving the viewer
application request at
404, adds client device 100 to a multicast list at 405. A multicast list may
have a plurality
of client devices registered. Server 120 may broadcast a video stream to all
client devices
100 registered on the multicast list at 407. Client device 100 receives the
broadcasted
video stream and displays it on a display 220 of the client device 100 at 408.
[00431 FIG. 5 illustrates a method for initializing the server 120. On power
up or reset
server 120 runs an initial boot-up sequence at 501. A check is performed to
determine
whether this is the first time that server 120 is operating at 502. If server
120 has never
operated in the past, then tuner 306 performs a scan across all channels to
detect the
presence of an over-the-air signal at 503. In other embodiments, tuner 306 may
perform a
scan based on a user request, at selected time intervals, or upon detection of
pre-defined
events. Once a channel scan is complete, information associated with a list of
available
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channels is stored in a data store 130 of server 120 at 504. This information
may include
the frequency of the channel, the quality of the signal associated with the
channel, and
other meta or ancillary data associated with the channel. Meta or ancillary
data may
include (without limitation) such parameters as: preferred antenna and
impedance switch
values; as well as signal scan parameters such as PER, BER, SNR, gain, signal
strength,
and multi-path detection. The signal scan parameters may be used to compare
initial scan
parameters with the current signal to determine if a re-scan of the input
signal is required.
Meta data or ancillary data associated with the channel may be retrieved from
the signal,
it may be pre-defined, or it may be retrieved by some other means (for
example, over the
network). Using this information, an electronic programming guide (EPG), such
as shown
in FIG. 10, maybe generated at 505. The guide includes but is not limited to
information
pertaining to the content being delivered and the scheduling of the content
being
delivered.
[0044] The data used to populate the EPG may be retrieved from the over-the-
air signal
or over the network. In one example, server 120 may access the internet or
some other
data store over the network to retrieve the data. Once the EPG has been
generated, the
tuner 306 is set to receive a default channel at 506. Once the default channel
has been set,
the tuner 306 isolates the information in a signal associated with the default
channel to
produce an intermodulated carrier wave, the intermodulated carrier wave is
then
demodulated to a data stream in a first format by the demodulator 307, and in
the
embodiment shown transcoded to a data stream in a second format by the
transcoder 308
in preparation for distribution over a network at 507. Prior to distribution
over the
network, data in the second format may be packaged in a standard network
transport
protocol, such as TCP/IP (the set of protocols which enable computers to
communicate
over the Internet) to produce a network transport stream. Availability of the
server 120 is
then broadcast over the network at 508. In another embodiment, server 120 may
respond
to a request from a client device 100 by indicating its availability. At 509
server 120 waits
for a communication from a client device 100.
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[00451 FIG. 6 illustrates a method for retrieving and displaying an electronic
programming guide. In this embodiment, client device 100 is processing data
from server
120 to render video associated with a selected or default channel. Client
device 100 may
request an electronic programming guide from server 120 at 601. Server 120 may
update
the stored electronic programming guide information and send the electronic
programming guide information to client device 100 at 602. In another example,
} electronic programming guide information may be sent to client device 100
without
updating the information. Client device 100 receives the electronic
programming guide
data and renders a view based on the information on display 220 at 603. A user
operating
the client device 100 may navigate the electronic programming guide
information at 603.
FIG. 10 is an example of an electronic programming guide. A user may select a
channel
to be displayed on client device 100 at 604. The user-selected channel is sent
from client
device 100 to server 120. Server 120 may determine whether the user-selected
channel is
the same as the channel that tuner 306 is currently tuned to at 605 (the
original channel).
If server 120 determines at 605 that the user-selected channel is different
from the
original channel, then tuner 306 may produce an intermodulated carrier wave
associated
with the user-selected channel which is then demodulated to a data stream in a
first
format by demodulator 307 and in the embodiment shown transcoded to a data
stream in
a second format by transcoder 308 at 606. The data stream in the second format
is then
packaged to produce a network transport stream and delivered to client device
100 where
it is processed to render video on display 220 of client device 100 at 607. If
server 120
determines at 605 that the selected channel is the same, no changes need to be
made and
tuner 306, demodulator 307, and transcoder 308 continue to deliver a network
data stream
with content from the original channel over the network to client device 100
which is
processed to render video on display 220 of client device 100 at 607.
100461 FIG. 7 illustrates a method for changing channels. A user may request a
channel
change at a client device 100 at 702. This request maybe transmitted to server
120. A
user may request a change to the next/previous channel or a user may request a
change to
a channel not previously selected. Server 120 requests that the tuner 306
change the new
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user-selected channel at 703. Tuner 306 tunes to the user-selected channel to
produce an
intermodulated carrier wave associated with the user-selected channel at 703.
The
intermodulated carrier wave is then demodulated to produce a data stream in a
first
format and transcoded to produce a data stream in a second format at 704. The
data
stream in a second format is packaged to produce a network transport stream.
[00471 If not on the list already, client device 100 maybe added to a
multicast list and
server 120 broadcasts a video stream encoded in a second format to all devices
on the
multicast list by delivering the network transport stream over the network at
705. In a
further embodiment, broadcast over a network maybe implemented using UDP, or
some
other suitable network protocol. Client device 100 receives the network
transport stream
and, upon processing the transport stream, renders the video on display 220 at
706.
100481 FIG. 8 illustrates a method converting an over-the-air signal to a
video stream that
may be distributed over a network. An over-the-air signal is received by a one
or more
independent antennas 301 or a plurality of antennas 312 at 800. Signal
information
associated with a selected channel is isolated from the over-the-air signal to
produce an
intermodulated carrier wave which is associated with a selected channel at
801. The
isolated signal information is demodulated to produce a data stream in a first
format 802.
The data stream in a first format is transcoded into a data stream in a second
format 803.
The data stream in the second format is packaged into data in a standard
network
transport protocol to produce a network transport stream at 804. The network
transport
stream is distributed over a network to at least one client device 100 at 805.
The network
transport stream received at client device 100 may then be unpackaged and
rendered by a
viewer application for display in a display 220. In a further embodiment, step
803 may be
omitted and the data stream in a first format may be packed into data in a
standard
network transport protocol to produce a network transport stream. In this
embodiment,
bandwidth and client device 100 must be sufficient to deliver and render the
data in a first
format.
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[0049] The data stream may be delivered to client devices by over-the-air
broadcast,
coaxial cable, wireless network, fiber, Ethernet cable, twisted pair, and any
other suitable
transmission medium; may be transmitted in any suitable protocol including
without
limitation Internet Protocol (IP) with or without compression; and may be
combined with
or isolated from other signals via signal multiplexing, switched digital video
or other
band selection/combining techniques.
[0050] FIG. 9 illustrates a block diagram of a further embodiment of a system
for
receiving an `over-the-air' (also sometimes known as `on-the-air' or `off-
air') signal and
distributing selected content of the received signal over a network. In this
embodiment
server 910 comprises a signal selector 905, a plurality of tuners 906, a
demodulator 907
for each of the plurality of tuners 906, a transcoder 908 for each of the
plurality of
demodulators 907, and at least one communications interface 909. Server 910 is
configured to receive signals from one or more signal sources (for example,
cable
(CATV), antenna, a plurality of antennas, LCU, and the like). The signal
selector 905 in
conjunction with a signal switch (not shown) selects one or more sources from
which to
obtain one or more signals. Each of the plurality of tuners 906 is configured
to isolate the
portion of the signal associated with a selected channel (i.e. frequency),
producing an
intermodulated carrier wave which carries the data associated with the
selected channel.
Each of the plurality of tuners 906 has an associated demodulator 907 for
demodulating
the intermodulated carrier wave, producing a plurality of data streams in a
first format.
Each of the demodulators 907 has an associated transcoder 908 for encoding the
demodulator output data stream in the first format into a data stream in a
second format,
producing a plurality of data streams in a second format. Each of the data
streams in a
second format may be sent via communications interface 909 to one or more of
the
plurality of display devices 901. In this way, display devices may display
different
channels from a single signal source, or they may display different channels
from more
than one signal source.
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[00511 Display devices 901 or client devices 100 comprise a means for
receiving and
unpacking a network stream into an audio/visual data stream. For example,
recent gaming
systems (Xbox (Trademark) from Microsoft, PS3 (Trademark) from Son}) are
capable of
performing such functions and may be advantageously used in conjunction with
the
systems described herein.
[00521 FIG. 12 illustrates a block diagram of a further embodiment of the
invention. In
this embodiment, a plurality of sampling R/C matrix slaves 1201 are provided
for
coupling to an A/C circuit or some other antenna. For each slave 1201, a tuner
1202 and
demodulator 1203 are provided. Note that while two of each slave 1201, tuner
1202 and
demodulator 1203 are illustrated as an example in FIG. 12, more than two of
each may be
provided without departing from the concept of the invention. In this example,
when the
system is initialized, the system samples the signal for each channel across
the frequency
spectrum to determine the appropriate resistance and capacitance values for
each channel.
When a channel is being sampled (i.e., the tuner 1202 tunes to the sampled
channel),
micro controller 1200 instructs slave 1201 to change resistance or capacitance
values, or
both, over a defined range. As the resistance/capacitance values are changed,
micro
controller 1200 retrieves signal quality parameters such as PER, BER, SNR,
gain, signal
strength, and multi-path detection from the tuner 1202 and demodulator 1203
respectively, and detects the resulting signal of the best quality to
determine the ideal
resistancelcapacitance values to use for the sampled channel. Those skilled in
the art will
appreciate that adjusting the resistance and capacitance values of the circuit
is only one
technique for matching impedance. Other techniques of impedance matching are
well
known to those skilled in the art.
100531 In one embodiment, once the micro controller 1200 determines the ideal
resistance/capacitance values for the sampled channel, the values are stored
in the
database lookup table 1204 and the micro controller instructs the tuner 1202
to sample
the next channel. This process is repeated until resistance capacitance values
are obtained
and stored in the database 1204 for each channel. Where two or more slaves
1201, tuners
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1202, and demodulators 1203 are provided, each of the tuners 1202 may
simultaneously
and independently sample different channels. Once database 1204 has been
populated,
when a tuner 1201 selects a channel, resistance and capacitance values are
retrieved from
database 1204 and supplied to the slave 1201 - slave 1201 then modifies the
resistance/capacitance values based on the values retrieved from the database
1204 to
optimize the signal for that channel. This avoids the need to repeat the
sampling
procedure each time a channel is selected. However, because signal quality may
change
from time to time depending on external factors, it would be advantageous to
periodically
sample each channel to determine whether values stored within the database
1204 still
provide the maximum gain for that channel.
[0054] The embodiment illustrated in FIG. 12 is most advantageous for coupling
to home
wiring such as an A/C circuit, but may also be coupled to some other antenna.
In this
embodiment, the quality of the signal is determined and compared with the
quality of
signals from other sources by the signal selector 305 for a selected channel.
Once
impedance has been matched by the LCU 317, signal selector 305 may then select
the
best signal source for obtaining a signal for a selected channel, and
instructs signal switch
319 to switch to the selected channel.
[0055] Various embodiments of the subject matter herein having been thus
described in
detail by way of example, it will be apparent to those skilled in the art that
variations and
modifications may be made without departing from the subject matter described
herein.
The invention includes all such variations and modifications as fall within
the scope of
the appended claims.
[0056] For example, it should be understood that the steps and the order of
the steps in
the processing described herein may be altered, modified, and/or augmented and
still
achieve the desired outcome. It will also be appreciated that although the
embodiments
herein have been directed generally to processing of over-the-air television
signals,
similar systems and methods may be carried out in respect of processing of
other types of
signals, such as audio content over radio, audio/video content over cable and
the like.
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[0057] Programming code may be adapted to provide the systems and methods
described
above. The code may be provided on many different types of computer-readable
media
including computer storage mechanisms (e.g., CD-ROM, diskette, RAM, flash
memory,
computer's hard drive, etc.).
[0058] The data may be stored in one or more data stores. The data stores may
be of
many different types of storage devices and coded constructs, such as RAM,
ROM, flash
memory, programming data structures, programming variables, etc. Data
structures may
be described as formats for use in organizing and storing data in databases,
programs,
memory, or other computer-readable media for use by a computer program.
[0059] The computer components, software modules, functions and data
structures
described herein may be connected directly or indirectly to each other in
order to allow
the flow of data needed for their operations. It is also noted that a module
or processor
includes but is not limited to a unit of programming code that performs a
software
operation, and can be implemented for example as a subroutine unit of code, or
as a
software function unit of code, or as an object (as in an object-oriented
paradigm), or as
an applet, or in a computer script language, or as another type of computer
code.
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