Patent Application
20170237456
The present invention relates generally to transmission of geolocation information, and, in particular, to the use of geolocation information to aid in antenna alignment.
As an antenna moves, an output signal provided thereby gets better or worse and yields instant feedback so aiming the antenna in a proper direction is imperative. Analog signals gradually fade when signal strength decreases, when electromagnetic interference increases, or when multipath propagation increases. However, digital signal data is either perfect or non-existent at the receiving end, which implies the possibility of a sudden loss of digital signal reception known as the “cliff effect.” Antennas can be difficult to aim when outputting digital signals because of the cliff effect and because of delays in decoding and displaying the signal. Existing methods to resolve antenna positioning are provided by smart antennas which allow for an easier antenna tuning process.
Smart antennas are antenna arrays that possess signal processing algorithms to identify a spatial signal signature such as the signal's direction of arrival (DOA). Some of these algorithms include Multiple Signal Classification (MUSIC), Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) algorithms, Matrix Pencil method, etc. Each of these algorithms includes a different way of finding a spatial spectrum of the antenna array and calculating the DOA from the peaks of this spectrum. Two conventional types of smart antennas include switched beam smart antennas and adaptive array smart antennas. Switched beam systems have options between available fixed beam patterns and system requirements dictate which beam to choose. Adaptive array antennas allow the antenna to choose a beam direction while nulling interfering signals. Beam direction can be estimated using DOA estimation methods. The DOA may subsequently be used to determine beamforming vectors that track and locate the antenna beam on the target. Beamforming creates a radiation pattern of the antenna array by adding the signal phases in the direction of the desired targets and nulling the pattern of undesired targets.
The standard for the Advanced Television Systems Committee (ATSC) “Smart Antenna Interface,” in particular, is called CEA-909. These antennas may either physically turn toward the signal, or they are stationary with elements pointed in different directions and the antennas only utilize the elements pointed toward the signal. Signal strength is determined through feedback from a control device, such as a digital-to-analog converter box.
As shown in
Television or other types of signals may require a directional antenna in order to achieve proper reception and enjoy a stronger received signal by avoiding interference and multipath problems. Aligning the receiving antenna for optimum reception may require complex manual alignment. However, this method is often difficult for an inexperienced user.
Therefore, another conventional system for simultaneous automatic alignment of two data antennae is illustrated in
As shown in
Conventional methods also involve the use of smart antennas to circumvent the problem of manual alignment through antennas that may be aligned automatically such as in the aforementioned smart antenna system of CEA-909 illustrated in
The type of receiving antenna determines its reception pattern, which could be any one of, but not limited to, a log periodic, Yagi type, etc. The 3 dB beamwidth corresponds to the width in degrees between the points on either side of the receiving antenna, where the power of the received signal will be half of its maximum power. The typical 3 dB beamwidth of an antenna may be between 60 to 90 degrees. Thus, the ability to reject channel interference from an interfering station is often limited.
As shown in
Even in instances where geolocation data is provided, the location of an antenna may change and so location information needs to be updated periodically. Additionally, there are scenarios where there is a blackout zone in the area of the transmitter. A receiver located in a region of the blackout zone would receive notification in the form of blackout bits alerting the receiver that it may not receive the transmitted signal. Because the location information needs to be updated periodically and in a timely manner, a new algorithm is necessary to enable the location information to be received more easily than normal program data. Thus, it is an object of this invention to improve the reception of antenna signals by not only obtaining geolocation information for a transmitter and receiver antenna but also utilizing a special robust modulation mode to receive the geolocation information of the transmitting antenna and calculate undesired channel interference in order to optimally align the antennas for clear transmission and reception of signals.
In one embodiment, a method for antenna alignment is provided at a receiving antenna. Geolocation information of the receiving antenna is entered. An auto-programming sequence is initiated to tune to channels received from a transmitting antenna. A plurality of transmitted signals is received from the transmitting antenna. Each of the plurality of transmitted signals is transmitted on a respective channel and includes geolocation information of the transmitting antenna, conditional access data, and a payload. A signal processor of the receiving antenna calculates a signal path between the receiving antenna and the transmitting antenna for receiving each of the plurality of transmitted signals based on the geolocation information of the receiving antenna and the geolocation information of the transmitting antenna. A storage device of the receiving antenna records, as part of a selection list, a channel number and signal path to the transmitting antenna for each of the plurality of transmitted signals. One of said plurality of transmitted signals is selected. The receiving antenna is aligned, using a pan/tilt system, to tune the selected one of the plurality of transmitted signals.
In another embodiment, a receiving antenna for antenna alignment is provided. A storage device of the receiving antenna receives geolocation information of the receiving antenna. A signal processor of the receiving antenna initiates an auto-programming sequence to tune to channels received from a transmitting antenna. The signal processor receives a plurality of transmitted signals from the transmitting antenna. Each of the plurality of transmitted signals is transmitted on a respective channel and includes geolocation information of the transmitting antenna, conditional access data, and a payload. The signal processor calculates a signal path between the receiving antenna and the transmitting antenna for receiving each of the plurality of transmitted signals based on the geolocation information of the receiving antenna and the geolocation information of the transmitting antenna. A pan/tilt system aligns the receiving antenna to tune the selected one of the plurality of transmitted signals. The storage device records, as part of a selection list, a channel number and signal path to the transmitting antenna for each of the plurality of transmitted signals.
These and other aspects, features and advantages of the present disclosure will be described or made apparent from the following detailed description of the preferred embodiments, which is to be read in connection with the accompanying drawings.
In the drawings, wherein like reference numerals denote similar elements throughout the views:
The exemplifications set out herein illustrate preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
The invention relates to a method and apparatus for optimizing the alignment of a directional receiving antenna such as a television signal receiver. The invention uses geolocation of a transmitting antenna and the directional receiving antenna to determine an optimum alignment for the directional receiving antenna. After the optimum alignment is determined, the directional receiving antenna may be aligned electronically and/or mechanically or instructions for aligning the antenna correctly may be provided to a user.
A transmitter sends its geolocation information, e.g. latitude and longitude, to a receiver. The location information may be acquired using any location finder technology such as GPS. Geolocation information of a receiver antenna may also be sent to a transmitter antenna periodically using a special robust modulation mode enabling location information to be received more easily than normal program data. The transmitter may be a television signal transmitter and the receiver may include geolocation information of the receiving antenna stored therein. The geolocation information may be built in to the memory, entered manually, or acquired using any location finder technology such as GPS. A micro-computer in the receiver may then calculate a line-of-sight direction which points the receiving antenna in the direction of the transmitter. In one mode, the information would be sent to a “smart antenna,” which allows the antenna to electronically and/or mechanically point in the calculated direction. Alternatively, a display could indicate instructions for proper manual alignment of the antenna to provide a line-of-sight direction.
The transmission of geolocation information from the receiving antenna to a transmitting antenna aids in aligning the receiving antenna in a line-of-sight direction that points to the transmitting antenna. The geolocation information may include latitude and longitude coordinates and may be used in conjunction with the transmitter location to optimize the alignment of a receiving antenna.
The receiving antenna, which may desire to receive an output signal from a transmitting antenna, periodically receives the latitude and longitude identifying the transmitting antenna's location from the transmitting antenna. The transmission mode, in which the transmitting antenna's location information is transmitted, may include a special robust modulation mode during which the location information is more easily received than the normal video or audio data. This enables the geolocation information to be received before the antenna has been optimally pointed. One of several mechanisms that may incorporate this invention is the ATSC digital television system. Conventional television signals are broadcast through 8-level vestigial sideband modulation (8 VSB), which converts a binary stream into an octal representation by amplitude modulating a sinusoidal carrier to one of eight levels. However, the special robust modulation mode of the present invention allows certain synchronizing signals to be transmitted using binary modulation instead of 8 VSB. These data field synchronizing signals include a special pseudo-random (PN) sequence that is transmitted in binary modulation and used principally for equalizer adjustment to reject multipath distortion. This digital sequence has additional bits that may include the geolocation information necessary to enable this invention. Additionally, location data for other transmitter stations could be stored in the memory of the receiver and used to modify the antenna pointing position to mitigate interference. Other algorithms which maximize the signal strength or minimize multipath propagation could be used in conjunction with this technique.
Other useful information, such as receiver location and distance from the transmitter to the receiver can be calculated and used to optimize the signal for other uses. For example, the receiving antenna's geolocation could be used to determine if the user was in a “blackout” location for certain events. A receiving antenna located in the blackout zone may receive conditional access data from the transmitting antenna that includes blackout bits alerting the receiving antenna that, due to its location, it is prevented from receiving the payload of the transmitted signal.
A receiving antenna may receive a transmitted signal 400 from a transmitting antenna. In addition to the payload 406, the transmitted signal 400 includes the transmitting antenna's geolocation 402. The transmitting antenna's geolocation may be used by the receiving antenna to determine an antenna position that is optimally conducive to reception of the transmitted signal 400. The transmitted signal 400 may also incorporate conditional access data 404. The conditional access data 404 is used by the receiving antenna to ascertain whether there are any conditions that preclude reception of the payload 406. For example, the conditional access data may include blackout bits that notify the receiving antenna of blackout zones within which the payload 406 is not permitted to be received or displayed. According to the receiving antenna's geolocation in conjunction with the conditional access data 404, the payload 406 may or may not be received or displayed.
A GPS (Global Positioning System) device 500 transmits the receiving antenna's geolocation signal 402 to the receiving antenna 504.
The receiving antenna 504 uses the pan/tilt system 506 to rotate between several antenna positions, each position represented by respective antenna elements 102, at which selected channels may be tuned. The selected channel corresponds to a frequency band at which the transmitting antenna 512 may transmit a transmitted signal 400. As part of an auto-programming sequence initialized by the signal processor 508, the receiving antenna 504 may be rotated into different positions able to create signal paths to the transmitting antenna 512 for tuning to different channels. The receiving antenna 504 may receive a plurality of transmitted signals 400 from the transmitting antenna 512 where each of the plurality of transmitted signals 400 is transmitted on a respective channel. The signal processor 508 may continue to use the auto-programming sequence to tune a next channel upon determining one of a signal path for one of the plurality of transmitted signals 400 or that no transmitted signal 400 is present on the respective channel. In addition to the payload 406, the transmitted signal 400 may include the transmitting antenna's geolocation 402. The transmitting antenna's geolocation 402 aids the receiving antenna 500 in determining an optimal antenna position, represented by an antenna element 102, for tuning the transmitted signal 400. The transmitted signal 400 may also incorporate conditional access data 404. The conditional access data 404 may be used by the receiving antenna to ascertain whether there are any conditions that preclude reception of the payload 406. The payload 406 of the transmitting signal 400 may be any one of, but not limited to, a television signal, radio signal, cellphone signal, IP signal, etc. to the receiving antenna 504.
Potential channel interference 510 from channels other than the selected channel is detected by a signal processor 508 within the pan/tilt system 506 of the receiving antenna 504. The signal processor 508 reads the output of the transmitted signal 400 to determine an optimal antenna position, represented by antenna elements 102, to minimize the channel interference 510 across the selected channel. If the position of the receiving antenna 504 in relation to the transmitting antenna 512 is the same as before signal path optimization, then the path trajectory and corresponding antenna position also remain the same. The transmitted signal 400 is then captured by the receiving antenna 504 in the determined optimal antenna position. The exemplary block diagram of
Although not shown in exemplary
As shown in
A GPS (Global Positioning System) device 500 transmits the receiving antenna's geolocation signal 502 to the receiving antenna 504.
The receiving antenna 504 uses the pan/tilt system 506 to rotate between at least four antenna positions, each position represented by respective antenna elements 102, at which selected channels may be tuned. The selected channel corresponds to a frequency band at which the transmitting antenna 512 may transmit a transmitted signal 400. As part of an auto-programming sequence initialized by the signal processor 508, the receiving antenna 504 may be rotated into different positions able to create signal paths to the transmitting antenna 512 for tuning to different channels. The receiving antenna 504 may receive a plurality of transmitted signals 400 from the transmitting antenna 512 where each of the plurality of transmitted signals 400 is transmitted on a respective channel. The signal processor 508 may continue to use the auto-programming sequence to tune a next channel upon determining one of a signal path for one of the plurality of transmitted signals 400 or that no transmitted signal 400 is present on the respective channel. In addition to the payload 406, a selected one of a plurality of transmitted signals 400 may include the transmitting antenna's geolocation 402. The transmitting antenna's geolocation 402 aids the receiving antenna 504 in determining an optimal antenna position, represented by an antenna element 102 for tuning the transmitted signal 400. The transmitted signal 400 may also incorporate conditional access data 404. The conditional access data 404 may be used by the receiving antenna to ascertain whether there are any conditions that preclude reception of the payload 406. The payload 406 of the transmitting signal 400 may be any one of, but not limited to, a television signal, radio signal, cellphone signal, IP signal, etc. to the receiving antenna 504.
However, if the conditional access data 404 of the transmitted signal 400, which may include blackout bits, indicates that the receiving antenna lies within a blackout region 700, then the payload signal 406 cannot be, at least one of, received or displayed by the receiving antenna 504. The signal processor 508 accepts the blackout bits as indicating a command to display a message indicating that the receiving antenna 504 is within the blackout region 700 and may provide an alternative transmitted signal 300 upon determining that the receiving antenna 504 is within the blackout region 700.
In Step S90, it is determined whether the last channel tuned in Step 80 is the last channel. If not, the method returns to step S50 and the antenna is rotated four or more positions to tune to a next channel. If it is determined in Step S90 that the channel to be tuned in Step S80 is the last channel, then a signal path is optimized in Step S100 to reduce interference. The potential interference from all other channels is determined for each channel in Step S110. Based on the calculated channel interference, the receiving antenna alignment is offset in order to minimize interference in Step S120. The alignment of the receiving antenna is not changed if the optimal signal path remains the same.
It is determined if the payload of the transmitted signal is permitted to be received based on the conditional access data of the transmitted signal and whether the conditional access data contains blackout bits that indicate the receiving antenna's geolocation lies within a blackout zone in Step S130. For example, if the receiver is located in a blackout zone, the payload of the signal may not be permitted to be received or displayed in Step S140. If it is permitted for the antenna to receive the signal, the signal is included in an accepted channel list and sent according to invention principles, as stated in Step S150.
It should be understood that the elements shown and discussed above, may be implemented in various forms of hardware, software, or combinations thereof. The present description illustrates the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope. All examples and conditional language recited herein are intended for informational purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herewith represent conceptual views of illustrative circuitry embodying the principles of the disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo-code, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2015/044635 | 8/11/2015 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62041691 | Aug 2014 | US |
