Patent Application
20070266417
The present invention relates to portable electronic devices and, more particularly, to portable electronic devices enabled for mobile television and related methods and computer program products.
Recently, there has been a proliferation of features in the field of portable communications. Portable electronic devices, such as cordless and cellular telephones, pagers, wireless modems, wireless email devices, personal digital assistants (PDAs) with communication functions, MP3 players and other portable communications devices are becoming more commonplace. Some of these portable electronic devices are equipped with the capability to view television programs.
To provide television service, portable electronic devices may use a Digital Video Broadcasting: Handhelds (DVB-H) standard, which is basically an extension of older DVB-Terrestrial(DVB-T) standard. In particular, DVB-H is a terrestrial digital TV standard that uses less power in a receiving device, for example, a portable electronic device, than DVB-T, thus, allowing the receiving device to move freely while receiving the transmission. Accordingly, DVB-H is more suitable for portable electronic devices than DVB-T and allows the portable electronic devices to receive digital TV broadcasting over, for example, the digiTV network, i.e., without using mobile networks.
Some embodiments of the present invention provide portable electronic devices including a digital video broadcast (DVB) receiver and a DVB frequency adjustment module. The DVB receiver is configured to use a reference clock of the portable electronic device as a DVB reference clock. A DVB frequency adjustment module is configured to receive adjustment information associated with the reference clock of the portable electronic device and adjust frequency settings of the DVB receiver responsive to the adjustment information.
In further embodiments of the present invention, the adjustment information may be a software signal indicating a magnitude of a frequency change of the reference clock or a hardware signal that indicates a frequency change of the reference clock. The DVB frequency adjustment module may be further configured to adjust the frequency settings of the DVB receiver based on the magnitude of the frequency change of the reference clock. In certain embodiments of the present invention, the DVB frequency adjustment module may be further configured to determine a doppler shift associated with the frequency change of the reference clock responsive to the hardware signal and adjust the frequency settings of the DVB receiver based on the magnitude of the frequency change of the reference clock.
In still further embodiments of the present invention, the adjustment information may be generated in response to a synchronization of the reference clock with a network clock. The received adjustment information may be received before or after reference clock is adjusted. In certain embodiments of the present invention, the DVB frequency adjustment module may be further configured to adjust the frequency settings of the DVB receiver within the portable electronic device.
Some embodiments of the present invention provide a method of adjusting frequency settings of a digital video broadcast receiver. Adjustment information associated with a reference clock of a portable electronic device is received. The reference clock of the portable electronic device is used as a DVB reference clock. Frequency settings of the DVB receiver are adjusted responsive to the adjustment information.
In further embodiments of the present invention, the adjustment information may include a software signal indicating a magnitude of a frequency change of the reference clock or a hardware signal that indicates a frequency change of the reference clock. The frequency settings of the DVB receiver may be adjusted based on the magnitude of the frequency change of the reference clock. In certain embodiments of the present invention, a doppler shift associated with the frequency change of the reference clock may be determined responsive to the hardware signal and the frequency settings of the DVB receiver may be adjusted based on the determined doppler shift.
In still further embodiments of the present invention, the adjustment information may be received before or after the reference clock is adjusted. The frequency settings of the DVB receiver may be adjusted within the portable electronic device.
Some embodiments of the present invention provide a computer program product for adjusting frequency settings of a digital video broadcast receiver. A computer readable medium having computer readable program code embodied therein is provided. The computer readable program medium includes computer readable program code configured to receive adjustment information associated with a reference clock of a portable electronic device. The reference clock of the portable electronic device is used as a DVB reference clock. Computer readable program code configured to adjust frequency settings of the DVB receiver responsive to the adjustment information is also provided.
In further embodiments of the present invention, the adjustment information may include a software signal indicating a magnitude of a frequency change of the reference clock or a hardware signal that indicates a frequency change of the reference clock. The computer readable program code configured to adjust may further include computer readable program code configured to adjust the frequency settings of the DVB receiver based on the magnitude of the frequency change of the reference clock. In certain embodiments of the present invention, the computer readable program code configured to adjust may further include computer readable program code configured to determine a doppler shift associated with the frequency change of the reference clock responsive to the hardware signal and adjust the frequency settings of the DVB receiver based on the determined doppler shift.
In still further embodiments of the present invention, the computer readable program code configured to receive adjustment information may further include computer readable program code configured to receive the adjustment information before or after the reference clock is adjusted. The computer readable program code configured to adjust may further include computer readable program code configured to adjust the frequency settings of the DVB receiver within the portable electronic device.
Specific exemplary embodiments of the invention now will be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the particular exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.
As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes,” “comprises,” “including” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include wirelessly connected or coupled. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
As used herein, a “portable electronic device” includes both devices having only a wireless signal receiver without transmit abilities and devices having both receive and transmit hardware capable of two-way communication over a two-way communication link. Such devices may include cellular or other communications devices with or without a multi-line display; Personal Communications System (PCS) terminals that may combine a voice and data processing, facsimile and/or data communications capabilities; Personal Digital Assistants (PDA) that can include a radio frequency receiver and a pager, Internet/Intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; and/or conventional laptop and/or palmtop computers or other appliances, which include a radio frequency receiver. As used herein, a “portable electronic device” may be portable, transportable, installed in a vehicle (aeronautical, maritime, or land-based), or situated and/or configured to operate locally and/or in a distributed fashion at any other location(s) on earth and/or in space.
As discussed herein with respect to
Portable electronic devices according to some embodiments of the present invention may include a DVB-H receiver including a DVB-H receiver and transmitter. The DVB-H receiver may use a reference clock of the portable electronic device as a DVB-H reference clock. This may provide advantages over devices that provide a dedicated reference clock to the DVB-H receiver as these added components may increase the size and increase the manufacturing cost of the device. However, using the reference clock of the portable electronic device as the DVB-H reference clock may also cause problems.
In particular, the reference clock of the portable electronic device is periodically or randomly updated to be synchronized with a network clock, for example, Global System for Mobile (GSM) communication and/or Universal Mobile Telephone System (UTMS) base station clocks. From the DVB-H receiver point of view, this synchronization may look like a doppler shift, which may cause degraded signal quality. Degraded signal quality may lead to decreased picture quality as discussed further herein.
Accordingly, portable electronic devices, methods and computer program products according to some embodiments of the present invention may be configured to receive adjustment information associated with a reference clock of a portable electronic device where the reference clock of the portable electronic device is used as a DVB reference clock and adjust frequency settings of the DVB receiver responsive to the adjustment information. Thus, according to some embodiments of the present invention the DVB receiver may be fed by the reference clock of the portable electronic device without sacrificing quality of the signal due to perceived doppler shifts as will be discussed further herein with respect to
It will be understood that although some embodiments of the present invention are discussed herein with respect to GSM and UMTS, embodiments of the present invention are not limited to this configuration. For example, embodiments of the present invention may used to correct doppler shift problems of a DVB receiver associated with synchronization of portable electronic devices to any network clock without departing from the scope of the present invention.
Referring first to
According to some embodiments of the present invention, radio access technologies and/or WLANs may be used as an access media between the portable electronic device 22 and the wireless communication network 20 illustrated in
The portable electronic device 22 includes a portable housing 23 and may include, a keypad 26, a display 28, a speaker 32, a microphone 34, a transceiver 36, and a memory 38, any of which may communicate with a controller (processor) 42. Furthermore, the portable electronic device 22 also includes a DVB-H frequency adjustment module 30 and a DVB-H receiver 50 according to some embodiments of the present invention, which also communicate with the controller 42. The controller 42 can be any commercially available or custom microprocessor.
It will be understood that although the DVB-H frequency adjustment module 30 and the DVB-H receiver 50 are illustrated as one cohesive module in
As further illustrated, the transceiver 36 typically includes a transmitter circuit 44 and a receiver circuit 46, which respectively transmit outgoing radio frequency signals to the base station transceiver 24 and receive incoming radio frequency signals, such as voice call and data signals, from the base station transceiver 24 via an antenna 48. The antenna 48 may be an embedded antenna, a retractable antenna or any antenna known to those having skill in the art without departing from the scope of the present invention. The radio frequency signals transmitted between the portable electronic device 22 and the base station transceiver 24 may include both traffic and control signals (e.g., paging signals/messages for incoming calls), which are used to establish and maintain a voice call communication with another party or to transmit and/or receive data, such as e-mail or Multimedia Message Service (MMS) messages, with a remote device. The controller 42 may support various functions of the portable electronic device 22, including functions related to the DVB-H frequency adjustment module 30 and the DVB-H receiver 50 of the portable electronic device 22 according to some embodiments of the present invention.
In some embodiments of the present invention, the base station transceiver 24 is a radio transceiver(s) that defines a cell in a cellular network and communicates with the portable electronic device 22 and other portable electronic devices in the cell using a radio-link protocol. Although only a single base station transceiver 24 is shown, it will be understood that many base station transceivers may be connected through, for example, a mobile switching center and other devices, to define a wireless communications network.
As illustrated in
It will be understood that although embodiments of the present invention discussed herein include the DVB-H receiver 50 being fed by the reference clock 31 of the portable electronic device, embodiments of the present invention are not limited to this configuration. Any aspect of the DVB system may be fed by the reference clock 31 without departing from the scope of the present invention.
In some embodiments of the present invention, the adjustment information may be provided to the frequency adjustment module 30 as a software signal indicating a magnitude of a frequency change of the reference clock 31. In further embodiments of the present invention, the adjustment information may be provided to the DVB-H frequency adjustment module 30 as a hardware signal that indicates a frequency change of the reference clock. The DVB frequency adjustment module 30 may then be configured to determine a doppler shift associated with the frequency change of the reference clock responsive to the hardware signal and adjust the frequency settings of the DVB receiver based on the determined magnitude of the frequency change of the reference clock. The adjustment information may be provided to the DVB-H frequency adjustment module 30 before or after the reference clock is adjusted without departing from the scope of the present invention.
Accordingly, as discussed herein, using a reference clock of the portable electronic device as a reference clock of a DVB-H receiver associated with the portable electronic device may cause problems. For example, degradation of signal quality may occur when the reference clock is updated as the clock update may be viewed as a doppler shift to the DVB-H receiver. For example, DVBM is Orthogonal Frequency Division Multiplexing (OFDM) based. OFDM, being a multi-carrier system, is sensitive to clock noise and reference clock adjustments. This could lead to degraded radio frequency (RF) performance, which in turn could cause, for example, degraded video quality. Thus, according to some embodiments of the present invention, portable electronic devices, methods and computer program products are provided that adjust the frequency settings of the DVB-H receiver responsive to a reference clock adjustment. Therefore, some embodiments of the present invention may provide improved signal quality, without providing a dedicated reference clock for the DVB-H receiver. Thus, relatively inexpensive and small devices may be provided.
Operations of portable electronic devices according to some embodiments of the present invention will now be discussed with respect to the flowcharts of
Operations according to further embodiments of the present invention will now be discussed with respect to the flowchart of
Operations according to further embodiments of the present invention will now be discussed with respect to the flowchart of
As will be appreciated by one of skill in the art, the present invention may be embodied as a portable electronic device, method or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, a software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. Any suitable computer readable medium may be utilized including hard disks, CD-ROMs, optical storage devices, a transmission media such as those supporting the Internet or an intranet, or magnetic storage devices.
Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java®, Smalltalk or C++. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language and/or a lower level assembler language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Furthermore, the present invention was described in part above with reference to flowchart illustrations and/or block diagrams of portable electronic devices, methods, and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The diagrams of
In the drawings and specification, there have been disclosed exemplary embodiments of the invention. Although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined by the following claims.
