US 20090161654A1
`
`as) United States
`a2) Patent Application Publication co) Pub. No.: US 2009/0161654 Al
`Caiet al.
`(43) Pub. Date:
`Jun. 25, 2009
`
`
`(54) SYSTEM AND METHODFOR UPLINK
`TIMING SYNCHRONIZATION
`
`(22)
`
`Filed:
`
`Dec. 18, 2008
`
`Related U.S. Application Data
`
`(75)
`
`Inventors:
`
`Zhijun Cai, Euless, TX (US);
`James Earl Womack, Bedford, TX
`(US); Yongkang Jia, Kanata (CA)
`
`(60) Provisional application No. 61/015,401, filed on Dec.
`20, 2007.
`
`Publication Classification
`
`Correspondence Address:
`Research in Motion Corp./CR
`Attn: Glenda Wolfe
`5000 Riverside Drive, Bldg. 6, Brazos East, Suite
`100
`Irving, TX75039 (US)
`
`(73) Assignee:
`
`Research in Motion Limited,
`Waterloo (CA)
`
`(21) Appl. No.:
`
`12/338,299
`
`(51)
`
`Int. Cl.
`(2006.01)
`HO04J 3/06
`(52) US. CD. eeccecccesscceecssescsseessneesssessesessneessneesans 370/350
`
`(57)
`ABSTRACT
`A system and method are disclosed for providing uplink
`timing synchronization in a wireless communication system.
`The uplink timing synchronization may be provided via a
`specific message sent from the user equipment to a network
`access device, or may be calculated based upon data received
`at the network access device from the user equipment.
`
`Receive an uplink timing signal instruction message
`
`Determine time interval to send timing signal transmission in accordance with
`timing signal instruction message
`
`
`
` valuate if there is
`
`
`No
`
`uplink data to be
`sent
`
`
`
`Send uplink timing
`Send data
`
`signal transmission
`
`
`
`1
`
`APPLE 1007
`
`1
`
`APPLE 1007
`
`

`

`Patent Application Publication
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`Jun. 25, 2009 Sheet 1 of 8
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`US 2009/0161654 Al
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`Patent Application Publication
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`Jun. 25,2009 Sheet 2 of 8
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`US 2009/0161654 Al
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`FIG.3
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`Patent Application Publication
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`Jun. 25,2009 Sheet 3 of 8
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`US 2009/0161654 Al
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`Network
`Access
`Equipment
`
`24]
`
`UE
`
`243
`
`FIG 4
`
`Receive an uplink timing signalinstruction message
`
`uplink data to be
`
`
`
`Determine time interval to send timingsignal transmission in accordance with
`timing signal instruction message
`
`
` valuate ifthere is
`sent
`
`
`
`Send uplink timing
`
`
`signal transmission
`
`
`
`
`259
`
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`
`FIG. 5
`
`4
`
`

`

`Patent Application Publication
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`Jun. 25,2009 Sheet 4 of 8
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`US 2009/0161654 Al
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`261
`
`
`
`
`
`Receive a message in a timeinterval
`
`263
`
`
`
`No
`
`267
`Was an uplink
`timing signal
`
`transmission
`
`received?
`
`
`Calculate uplink timing ~
`Calculate uplink
`
`alignment adjustment
`
`timing alignment
`
`based upon data
`
`adjustment based upon
`
`
`received in the time
`
`uplink timing signal
`
`interval
`
`
`transmission received
`
`
`
`
`FIG. 6
`
`Receive Module
`
`Determination Madnle
`
`
` IQ
`
`
`
`
`803
`
`
`
`807
`
`Evaluation Module
`
`805
`
`Transmission Module
`
`FIG.11
`
`5
`
`

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`Patent Application Publication
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`Jun. 25,2009 Sheet 5 of 8
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`US 2009/0161654 Al
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`6
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`

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`Patent Application Publication
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`Jun. 25,2009 Sheet 6 of 8
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`US 2009/0161654 Al
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`FIG,®
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`

`

`Patent Application Publication
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`Jun. 25,2009 Sheet 7 of 8
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`US 2009/0161654 Al
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`7090
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`

`

`Patent Application Publication
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`Jun. 25,2009 Sheet 8 of 8
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`US 2009/0161654 Al
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`20
`
`Receive Module
`
`
`
`
`Evaluation Module
`
`
`Calculation Module
`
`
`FIG, [2
`
`9
`
`

`

`US 2009/0161654 Al
`
`Jun. 25, 2009
`
`SYSTEM AND METHOD FOR UPLINK
`TIMING SYNCHRONIZATION
`
`taken in connection with the accompanying drawings and
`detailed description, wherein like reference numerals repre-
`sent like parts.
`CROSS-REFERENCE TO RELATED
`
`[0007] FIG.1is anillustration ofa cellular network accord-
`APPLICATIONS
`ing to an embodimentof the disclosure.
`[0008]
`FIG.2 is an illustration ofa cell ina cellular network
`according to an embodimentofthe disclosure.
`[0009]
`FIG. 3 is an illustration of a one possible uplink
`transmission channel for LTE.
`
`[0001] The present application claimspriority to U.S. Pro-
`visional Patent Application No. 61/015,401, filed Dec. 20,
`2007, by Zhijun S. Cai, et al, entitled “System and Method for
`Uplink Timing Synchronization,’ which is incorporated by
`reference herein as if reproducedin its entirety.
`
`BACKGROUND
`
`FIG. 4 is a timing diagram.
`[0010]
`FIG. 5 is a flow chart corresponding to one UE
`[0011]
`embodiment.
`[0012]
`FIG.6is a flow chart corresponding to one network
`access equipment embodiment.
`[0013]
`FIG. 7 is a diagram of a wireless communications
`system including a mobile device operable for some of the
`various embodiments ofthe disclosure.
`[0014]
`FIG. 8 is a block diagram of a mobile device oper-
`able for some of the various embodiments ofthe disclosure.
`
`Intraditional wireless telecommunications systems,
`[0002]
`transmission equipment in a base station transmits signals
`throughout a geographical region known as a cell. As tech-
`nology has evolved, more advanced network access equip-
`menthas been introduced that can provide services that were
`not possible previously. This advanced network access equip-
`FIG. 9 is a diagram of a software environmentthat
`[0015]
`ment might include, for example, an enhanced node-B (eNB)
`rather than a basestation or other systems and devicesthat are
`may be implemented on a mobile device operable for some of
`the various embodiments of the disclosure.
`more highly evolved than the equivalent equipmentinatra-
`ditional wireless telecommunications system. Such advanced
`[0016]
`FIG. 101s an exemplary general purpose computer
`or next generation equipmentis typically referred to as long-
`according to one embodimentof the present disclosure.
`term evolution (LTE) equipment. For LTE equipment, the
`[0017]
`FIG. 11 is an exemplary diagram of modulesin the
`UE.
`region in which a wireless device can gain access to a tele-
`communications network might be referred to by a name
`other than “cell”, such as “hot spot”. As used herein, the term
`“cell” will be used to refer to any region in which a wireless
`device can gain access to a telecommunications network,
`regardless of whether the wireless device is a traditional cel-
`lular device, an LTE device, or some other device.
`[0003] Devices that might be used by users in a telecom-
`munications network can include both mobile terminals, such
`as mobile telephones, personal digital assistants, handheld
`computers, portable computers,
`laptop computers,
`tablet
`computers and similar devices, and fixed terminals such as
`residential gateways, televisions, set-top boxes and the like.
`Such devices will be referred to herein as user equipment or
`UE.
`
`FIG. 12 is an exemplary diagram of modulesin the
`[0018]
`network access equipment.
`
`DETAILED DESCRIPTION
`
`It should be understoodat the outset that although
`[0019]
`illustrative implementations of one or more embodiments of
`the present disclosure are provided below, the disclosed sys-
`tems and/or methods may be implemented using any number
`of techniques, whether currently knownorin existence. The
`disclosure should in no way be limited to the illustrative
`implementations, drawings, and techniquesillustrated below,
`including the exemplary designs and implementationsillus-
`trated and described herein, but may be modified within the
`scope of the appended claims along with their full scope of
`Services that might be provided by LTE-based
`[0004]
`equivalents.
`equipmentcan include broadcasts or multicasts of television
`[0020]
`FIG. 1 illustrates an exemplary cellular network 100
`programs, streaming video, streaming audio, and other mul-
`according to an embodimentof the disclosure. The cellular
`timedia content. Such services are commonly referred to as
`network 100 may includeaplurality of cells 102,, 102,, 102,,
`multimedia broadcast multicast
`services
`(MBMS). An
`102,, 102;, 102, 102,, 102,, 102,, 102,,, 102,,, 102,,,
`MBMSmight be transmitted throughout a single cell or
`102,,, and 102,, (collectively referred to as cells 102). As is
`throughout several contiguous or overlapping cells. The
`apparent to persons of ordinary skill in the art, each of the
`MBMSmay be communicated from an eNBto a UE using
`cells 102 represents a coverage area for providing cellular
`point-to-point (PTP) communication or point-to-multipoint
`services of the cellular network 100 through communication
`(PTM) communication.
`from a network access equipment(e.g., eNB). Whilethecells
`[0005]
`In wireless communication systems, transmission
`102 are depicted as having non-overlapping coverage areas,
`from the network access equipment(e.g., eNB) to the UE is
`personsof ordinary skill in the art will recognize that one or
`referred to as a downlink transmission. Communication from
`moreof the cells 102 may havepartially overlapping cover-
`age with adjacentcells. In addition, while a particular number
`of the cells 102 are depicted, persons of ordinary skill in the
`art will recognizethat a larger or smaller numberofthecells
`102 may be includedin the cellular network 100.
`[0021] One or more UEs 10 maybepresent in each of the
`cells 102. Although only one UE 10 is depicted and is shown
`in only one cell 10212, it will be apparent to one of skill in the
`art that a plurality of UEs 10 maybe present in each of the
`cells 102. A network access equipment20 in each ofthe cells
`102 performs functions similar to those ofa traditional base
`station. That is, the network access equipments 20 provide a
`
`the UEto the network access equipmentis referred to as an
`uplink transmission. Wireless communication systems gen-
`erally require maintenance of timing synchronization to
`allow for continued communications. Maintaining uplink
`synchronization can be problematic, wasting throughput and/
`or decreasing battery life of an UE given that a UE may not
`alwayshave data to transmit.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For a more complete understanding ofthis disclo-
`[0006]
`sure, reference is now madeto the followingbrief description,
`
`10
`
`10
`
`

`

`US 2009/0161654 Al
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`Jun. 25, 2009
`
`radio link between the UEs 10 and other components in a
`telecommunications network. While the network access
`
`equipment 20 is shownonly in cell 10212, it should be under-
`stood that network access equipment would be present in each
`of the cells 102. A central control 110 mayalso be present in
`the cellular network 100 to oversee someof the wireless data
`transmissions within the cells 102.
`
`FIG. 2 depicts a more detailed view of the cell
`[0022]
`10212. The network access equipment 20 in cell 10212 may
`promote communication via a transmitter 27, a receiver 29,
`and/or other well known equipment. Similar equipment
`might be presentin the other cells 102. A plurality of UEs 10
`are present in the cell 10212, as might be the case in the other
`cells 102. In the present disclosure, the cellular systems or
`cells 102 are described as engaged in certain activities, such
`as transmitting signals; however, as will be readily apparent to
`one skilled in the art, these activities would in fact be con-
`ducted by components comprising thecells.
`[0023]
`In each cell, the transmissions from the network
`access equipment20 to the UEs 10 are referred to as downlink
`transmissions, and the transmissions from the UEs 10 to the
`network access equipment 20 are referred to as uplink trans-
`missions. The UE may include any device that may commu-
`nicate using the cellular network 100. For example, the UE
`may include devices such as a cellular telephone, a laptop
`computer, a navigation system, or any other devices known to
`persons of ordinary skill in the art that may communicate
`using the cellular network 100.
`[0024] The format of the uplink channel in LTE is shown
`schematically in FIG. 3. The transmission can be one of a
`numberofdifferent bandwidths(e.g., 1.25, 5, 15, or 20 MHz).
`In the time domain, the uplink is broken into frames, sub-
`frames and slots. A slot 201 is made up of seven orthogonal
`frequency division multiplexed (OFDM) symbols 203. Two
`slots 201 make up a sub-frame 205. A frameis a collection of
`10 contiguous sub-frames. Because the exact details of a
`sub-frame 205 may vary depending upon the exact imple-
`mentation of the LTE system, the following description is
`provided as an example only. The first symbol of the sub-
`frame 207 is where the sounding reference symbol (SRS) is
`placed. The UE will transmit using a constant-amplitude and
`zero-autocorrelation (CAZAC) sequence so that more than
`one UE may transmit simultaneously. The demodulation
`(DM)reference symbol (RS) is placed on the fourth symbol
`of each slot 209; and the control channel 211 is taken up byat
`least one resource block on the very outside edges of the
`frequency band.
`[0025] The SRS 207 is made available at the beginning, or
`end, of each sub-frame 205 and is broken down into several
`blocks of 12 sub-carriers that correspond to the samefre-
`quency bandwidth as a resource block. A UE mayuse one or
`all of those frequency blocks depending on the transmission
`bandwidth selected. The UE mayalso use every other fre-
`quency in one or more multiple blocks. The transmission of
`SRSs 205 is based on the time between subsequent SRS
`transmission by a single UE. FIG.3 also shows wherein time
`and frequency that
`the physical uplink control channel
`(PUCCH)211 is placed. Control signaling takes place in the
`PUCCH. In one embodiment,
`the system implements a
`hybrid automatic repeat request (HARQ) acknowledgement
`(ACK)/negative acknowledgement (NACK) feedback. An
`ACK or NACKis sent on the PUCCH 211 by the UEto the
`eNBto indicate whether a packet transmitted from the eNB
`
`wasreceived at that UE. The physical uplink shared channel
`(PUSCH)is used to send user data.
`[0026] The above description of the uplink channelis one
`implementation of an uplink channel proposed for LTE. It
`will be appreciated that other uplink channel configurations
`may be used wherein an uplink timing reference signal trans-
`mission (e.g., SRS) is sent during any portion of the uplink
`message, not necessarily only at the beginning or end of a
`specified time interval (e.g., slot).
`[0027]
`In order to maintain uplink synchronization, it is
`desirable for the network access equipment 20 (shown in FIG.
`1) to calculate the uplink channel conditions by analyzing
`signals sent from the UE 10. Onepossible timing diagram of
`signals sent between the network access equipment 20 and the
`UE 10 is shown in FIG.4. In this embodiment, the network
`access equipment 20 instructs the UE 10 when to send an
`uplink timing reference signal
`transmission (e.g., SRS),
`through use of an uplink timing reference signal transmission
`instruction message 241. The uplink timing reference signal
`transmission instruction message 241 may include any one of
`a variety of instructions. For example, the network access
`equipment 20 mayinstruct the UE 10 via the timing reference
`signal transmission instruction message 241 to send the tim-
`ing reference signal transmissions at a constant rate, or in
`bursts depending on the velocity of the UE 10 relative to the
`network access equipment 20. In response 243, the UE 10
`may send the timing reference signal transmissions(e.g.,
`SRS) in accordance with the instructions of the network
`access equipment 20. However, the sending of the timing
`reference signal transmissions may result in a waste ofnet-
`work resources and a drain on the UE battery if unnecessary.
`Alternatively, the UE 10 may choose notto send the timing
`reference signal transmission 1fthe UE 10 determinesthat the
`UE10 will be sending data in the same timeinterval that the
`UE 10 would havesentthe timing reference signal transmis-
`sion. By sending data and not the timing reference signal
`transmission, the UE 10 avoids interference that can result
`when the UEtransmits its CAZAC sequence.
`[0028]
`FIG. 5 illustrates an embodiment of such a method
`for uplink timing reference signal transmission ina UE 10. At
`block 251, the UE receives an uplink timing reference signal
`instruction message. Then, at block 253, the UE determines a
`time interval to send a timing reference signal transmission in
`accordance with the timing reference signal instruction mes-
`sage. Next, at block 255, the UE evaluates its buffers to
`determineif there is uplink datato be sent. If there is no data
`to be sent, at block 257 the UE sends the uplink timing
`reference signal transmission in the time interval in accor-
`dance with the uplink timing reference signal instruction
`message. However,if there is data to besent, at block 259 the
`UEsendthe data in the time interval.
`
`FIG.6 illustrates an embodiment of a method per-
`[0029]
`formed by the network access equipment 20. At block 261,
`the network access equipment20 first receives the message.
`Then, at block 263 the network access equipment 20 evalu-
`ates the time interval in which it expected to receive a timing
`reference signal instruction.If the network access equipment
`20 determinesthat no timing reference signal instruction was
`received,then at block 267 the network access equipmentwill
`calculate an uplink timing alignment adjustment based upon
`the data received. For example, in an LTE system, the data
`comprises a DM RS. The eNBcanthen use the DM RSto
`calculate the uplink timing alignment adjustment. Ifhowever,
`the network access equipment determinesthat an uplink tim-
`
`11
`
`11
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`

`

`US 2009/0161654 Al
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`Jun. 25, 2009
`
`10 maybe a portable, laptop or other computing device. The
`ing reference signal transmission wasreceived, at block 265
`UE 10 may support specialized activities such as gaming,
`the network access equipment calculates the uplink timing
`inventory control, job control, and/or task management func-
`alignment adjustment based uponthe uplink timing reference
`tions, and so on.
`signal transmission received.
`[0033] The UE 10 includesa display 402. The UE 10 also
`[0030]
`In order to carry out the above process, the UE 10
`includes a touch-sensitive surface, a keyboard or other input
`comprises a processor capable of performing the above pro-
`keys generally referred as 404 for input by a user. The key-
`cess. For simplicity, the different functions have been broken
`board maybea full or reduced alphanumeric keyboard such
`out into different modules. These modules may be imple-
`as QWERTY, Dvorak, AZERTY, and sequential types, or a
`mented separately or together. Further, these modules may be
`traditional numeric keypad with alphabetletters associated
`implemented in hardware, software, or some combination.
`with a telephone keypad. The input keys may includeatrack-
`Finally, these modules mayreside in different portions of the
`wheel, an exit or escape key, a trackball, and other naviga-
`UE memory. As illustrated in FIG. 11, the UE processor
`tionalor functional keys, which may be inwardly depressed to
`comprises a receive module 801, a determination module
`provide further input function. The UE 10 may present
`803, an evaluation module 805 and a transmission module
`optionsfor the user to select, controls for the user to actuate,
`807. The receive module 801 receives the uplink timing ref-
`and/or cursors or other indicators for the user to direct.
`erence transmission instruction message. The determination
`module 803 determines the time interval specified in the
`uplink timing reference transmission instruction message for
`transmitting the uplink timing reference transmission. The
`evaluation module 805 compares the time interval specified
`in the uplink timing reference transmission instruction mes-
`sage for transmitting the uplink timing reference transmission
`with the time interval to be used to transmit data. If the time
`interval for transmitting the uplink timing reference transmis-
`sion is the sameas the timeinterval for transmitting the data,
`the evaluation module 805 informs the transmission module
`
`[0034] The UE 10 may further accept data entry from the
`user, including numbersto dial or various parameter values
`for configuring the operation of the UE 10. The UE 10 may
`further execute one or more softwareor firmware applications
`in response to user commands. These applications may con-
`figure the UE 10 to perform various customized functions in
`responseto user interaction. Additionally, the UE 10 may be
`programmed and/or configured over-the-air, for example
`from a wireless basestation, a wireless access point, or a peer
`UE 10.
`
`807 not to send the uplink timing reference transmission.
`Otherwise, the transmission module 807 sends the uplink
`timing reference transmission.
`[0031] The network access equipment 20 also comprises a
`processor. As shown in FIG. 12, the processor comprises a
`receive module 901, an evaluation module 903 and a calcu-
`lation module 905. Again, these modules are defined for
`simplicity, and may be executed in software, hardware, firm-
`ware, or both. Additionally, these modules may be stored in
`the same or different memories. The receiver module 901
`
`receives the message. The evaluation module 903 evaluates
`the timeinterval in the message whereit expects to receive an
`uplink timing reference transmission. If an uplink timing
`reference transmission is received, the evaluation module 903
`sends the uplink timing reference transmission to the calcu-
`lation module 905 to calculate an uplink timing alignment
`adjustment. In an LTE system, the uplink timing reference
`transmission is a SRS. Ifan uplink timing reference transmis-
`sion is not received, then the evaluation module 905 sends a
`portion of the data in the specific time interval to the calcu-
`lation module. The calculation module then calculates the
`uplink timing alignment adjustment based uponthe portion of
`data received. In an LTE system the portion of data received
`is the DM RS.
`
`FIG.7 illustrates a wireless communications system
`[0032]
`including an embodimentofthe UE 10. The VE 10 is operable
`for implementing aspects of the disclosure, but the disclosure
`should notbe limited to these implementations. Though illus-
`trated as a mobile phone, the UE 10 maytake various forms
`including a wireless handset, a pager, a personal digital assis-
`tant (PDA), a portable computer, a tablet computer, or a
`laptop computer. Manysuitable devices combine someorall
`of these functions. In some embodiments of the disclosure,
`the UE 10 is not a general purpose computing device like a
`portable, laptop or tablet computer, but rather is a special-
`purpose communications device such as a mobile phone, a
`wireless handset, a pager, a PDA, or a telecommunications
`device installed in a vehicle. In another embodiment, the UE
`
`[0035] Among the various applications executable by the
`UE 10 are a web browser, which enables the display 402 to
`show a web page. The web page maybe obtainedvia wireless
`communications with a wireless network access node,a cell
`tower, a peer UE 10, or any other wireless communication
`network or system 400. The network 400 is coupled to a wired
`network 408, such as the Internet. Via the wireless link and the
`wired network, the UE 10 has access to information on vari-
`ous servers, such as a server 410. The server 410 may provide
`content that may be shownonthe display 402. Alternately, the
`UE 10 mayaccess the network 400 through a peer UE 10
`acting as an intermediary, in a relay type or hop type of
`connection.
`
`FIG. 8 showsa block diagram of the UE 10. While a
`[0036]
`variety of known components of UEs 10 are depicted, in an
`embodimenta subset of the listed components and/or addi-
`tional components not listed may be included in the UE 10.
`The VE 10 includes a digital signal processor (DSP) 502 and
`a memory 504. As shown, the UE 10 may further include an
`antenna andfront end unit 506, a radio frequency (RF)trans-
`ceiver 508, an analog baseband processing unit 510, a micro-
`phone 512, an earpiece speaker 514, a headset port 516, an
`input/output interface 518, a removable memory card 520, a
`universal serial bus (USB) port 522, a short range wireless
`communication sub-system 524,an alert 526, akeypad 528, a
`liquid crystal display (LCD), which may include a touch
`sensitive surface 530, an LCD controller 532, a charge-
`coupled device (CCD) camera 534, a camera controller 536,
`and a global positioning system (GPS) sensor 538. In an
`embodiment, the UE 10 mayinclude another kind ofdisplay
`that does not provide a touch sensitive screen. In an embodi-
`ment,
`the DSP 502 may communicate directly with the
`memory 504 without passing through the input/output inter-
`face 518.
`
`[0037] The DSP 502 or some other form of controller or
`central processing unit operates to control the various com-
`ponents of the UE 10 in accordance with embedded software
`or firmware stored in memory 504 or stored in memory con-
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`tained within the DSP 502itself. In addition to the embedded
`softwareor firmware, the DSP 502 may execute other appli-
`cations stored in the memory 504 or made available via infor-
`mation carrier media such as portable data storage media like
`the removable memory card 520 or via wired or wireless
`network communications. The application software may
`comprise a compiled set of machine-readable instructions
`that configure the DSP 502 to provide the desired function-
`ality, or the application software may be high-level software
`instructions to be processed by an interpreter or compiler to
`indirectly configure the DSP 502.
`[0038] The antenna andfront end unit 506 may be provided
`to convert between wireless signals and electrical signals,
`enabling the UE 10 to send and receive information from a
`cellular network or some other available wireless communi-
`cations networkor from a peer UE 10. In an embodiment,the
`antenna andfront end unit 506 may include multiple antennas
`to support beam forming and/or multiple input multiple out-
`put (MIMO)operations. As is known to those skilled in the
`art, MIMO operations may provide spatial diversity which
`can be used to overcomedifficult channel conditions and/or
`
`increase channel throughput. The antenna and front end unit
`506 mayinclude antenna tuning and/or impedance matching
`components, RF power amplifiers, and/or low noise amplifi-
`ers.
`
`removal, and other signal processing functions associated
`with wireless communications.
`In an embodiment,
`for
`example in a code division multiple access (CDMA)technol-
`ogy application, for a transmitter function the DSP 502 may
`perform modulation, coding, interleaving, and spreading, and
`for a receiver function the DSP 502 may perform despread-
`ing, deinterleaving, decoding, and demodulation. In another
`embodiment, for example in an orthogonal frequency divi-
`sion multiplex access (OFDMA)technology application, for
`the transmitter function the DSP 502 may perform modula-
`tion, coding, interleaving, inverse fast Fourier transforming,
`and cyclic prefix appending, and for a receiver function the
`DSP 502 may perform cyclic prefix removal, fast Fourier
`transforming, deinterleaving, decoding, and demodulation.
`In other wireless technology applications, yet other signal
`processing functions and combinationsof signal processing
`functions may be performed by the DSP 502.
`[0042] The DSP 502 may communicate with a wireless
`networkvia the analog basebandprocessing unit 510. Insome
`embodiments, the communication may provide Internet con-
`nectivity, enabling a user to gain access to content on the
`Internet and to send and receive e-mail or text messages. The
`input/output interface 518 interconnects the DSP 502 and
`various memories and interfaces. The memory 504 and the
`removable memory card 520 may provide software and data
`to configure the operation of the DSP 502. Amongthe inter-
`faces may be the USB interface 522 and the short range
`wireless communication sub-system 524. The USBinterface
`522 maybe used to charge the UE 10 and mayalso enable the
`UE 10 to function as a peripheral device to exchange infor-
`mation with a personal computer or other computer system.
`The short range wireless communication sub-system 524
`may include an infrared port, a Bluetooth interface, an IEEE
`802.11 compliant wireless interface, or any other short range
`wireless communication sub-system, which may enable the
`UE 10 to communicate wirelessly with other nearby mobile
`devices and/or wireless base stations.
`
`[0039] The RF transceiver 508 provides frequencyshifting,
`converting received RF signals to baseband and converting
`basebandtransmit signals to RF. In some descriptions a radio
`transceiver or RF transceiver may be understood to include
`other signal processing functionality such as modulation/
`demodulation, coding/decoding, interleaving/deinterleaving,
`spreading/despreading,
`inverse fast Fourier transforming
`(IFFT)/fast Fourier transforming (FFT), cyclic prefix append-
`ing/removal, and other signal processing functions. For the
`purposesof clarity, the description here separates the descrip-
`tion of this signal processing from the RF and/orradio stage
`and conceptually allocates that signal processing to the ana-
`[0043] The input/output interface 518 may further connect
`log baseband processing unit 510 and/or the DSP 502 or other
`the DSP 502to the alert 526 that, when triggered, causes the
`central processing unit. In some embodiments, the RF Trans-
`UE 10 to provide a noticeto theuser, for example, by ringing,
`ceiver 508, portions of the Antenna and Front End 506, and
`playing a melody, or vibrating. The alert 526 may serve as a
`the analog basebandprocessing unit 510 may be combined in
`mechanism for alerting the user to any of various events such
`one or more processing units and/or application specific inte-
`as an incomingcall, a new text message, and an appointment
`grated circuits (ASICs).
`reminderbysilently vibrating, or by playing a specific pre-
`[0040] The analog baseband processing unit 510 may pro-
`assigned melodyfor a particular caller.
`vide various analog processing of inputs and outputs, for
`[0044] The keypad 528 couples to the DSP 502 via the
`example analog processing of inputs from the microphone
`interface 518 to provide one mechanism for the user to make
`512 and the headset 516 and outputs to the earpiece 514 and
`selections, enter information, and otherwise provide inputto
`the headset 516. To that end, the analog baseband processing
`the UE 10. The keyboard 528 maybea full or reduced alpha-
`unit 510 may haveports for connecting to the built-in micro-
`numeric keyboard such as QWERTY, Dvorak, AZERTY and
`phone 512 andthe earpiece speaker 514 that enable the UE 10
`to be used as a cell phone. The analog baseband processing
`sequentialtypes, or a traditional numeric keypad with alpha-
`
`unit 510 mayfurther includeaport for connecting to a headset bet letters associated with a telephone keypad. The input keys
`or other hands-free microphone and speaker configuration.
`may include a trackwheel, an exit or escape key, a trackball,
`The analog baseband processing unit 510 may provide digi-
`and other navigational or functional keys, which may be
`tal-to-analog conversion in one signal direction and analog-
`inwardly depressedto provide further input function. Another
`to-digital conversion in the opposing signaldirection. In some
`input mechanism may be the LCD 530, which may include
`embodiments, at least some of the functionality of the analog
`touch screen capability and also display text and/or graphics
`baseband processing unit 510 may be provided by digital
`to the user. The LCD controller 532 couples the DSP 502 to
`the LCD 530.
`processing components, for example by the DSP 502 or by
`other central processing units.
`[0041] The DSP 502 may perform modulation/demodula-
`tion, coding/decoding, interleaving/deinterleaving, spread-
`ing/despreading, inverse fast Fourier transforming (IFFT)/
`fast Fourier transforming (FFT), cyclic prefix appending/
`
`[0045] The CCD camera 534, if equipped, enables the UE
`10 to take digital pictures. The DSP 502 communicates with
`the CCD camera 534 via the camera controller 536. In another
`embodiment, a camera operating according to a technology
`other
`than Charge Coupled Device cameras may be
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`employed. The GPS sensor 538 is coupled to the DSP 502 to
`decode global positioning system signals, thereby enabling
`the UE 10 to determine its position. Various other peripherals
`mayalso be included to provide additional functions, e.g.,
`radio andtelevision reception.
`[0046]
`FIG.9 illustrates a so