(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2009/0161654 A1
`
`Cai et al. Jun. 25, 2009 (43) Pub. Date:
`
`
`US 20090161654A1
`
`(54) SYSTEM AND METHOD FOR UPLINK
`TIMING SYNCHRONIZATION
`
`(22)
`
`Filed:
`
`Dec. 18, 2008
`
`Related US. Application Data
`
`(75)
`
`Inventors:
`
`Zhij un 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
`
`(51)
`
`Int. Cl.
`H04] 3/06
`
`(2006.01)
`
`Attm Glenda Wolfe
`5000 Riverside Drive, Bldg. 6, Brazos East, Suite
`100
`Irv1ng, TX 75039 (US)
`.
`(73) Ass1gnee:
`
`Research in Motion Limited,
`Waterloo (CA)
`
`(21) Appl. No.:
`
`12/338,299
`
`(52) us. Cl. ........................................................ 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.
`
`
`Determine time interval to send timing signal transmission in accordance with
`
`tuning Signal instruction message
`
`
`Receive an uplink timing signal instruction message
`
`
` No
`
`uplink data to be
`
`valuate if there is
`
`sent
`
`
` Send data
`Send uplink timing
`
`signal transmission
`
`
`1
`
`SAMSUNG 1007
`
`SAMSUNG 1007
`
`1
`
`

`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 1 of 8
`
`US 2009/0161654 A1
`
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`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 2 0f 8
`
`US 2009/0161654 A1
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`Patent Application Publication
`
`Jun. 25, 2009 Sheet 3 0f 8
`
`US 2009/0161654 A1
`
`Network
`
`Access
`
`Equipment
`
`24 l
`
`UE
`
`243
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`
`Receive an uplink timing signal insti'uction message
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`
`Determine time interval to send timing signal transmission in accordance with
`timing signal instruction message
`
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`valuate if there is
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`Send uplink timing
`
`signal transmission
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`4
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`

`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 4 of 8
`
`US 2009/0161654 A1
`
`261
`
`
`
`Receive a message in a time interval
`
`
`
`263
`
`
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` Yes
`
`
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`Was an uplink
`timing signal
`transmission
`
`
`received?
`
`
`
`Caiculate uplink timing '
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`Calculate upiink
`alignment adjustment
`
`
`based upon data
`tiniing alignment
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`received in the time
`adJiJstment based 1113011
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`uplmk timing Signal
`intervai
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`Determinafinn Module
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`Evaluation Module
`
`Transmission Module
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`807
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`FIG. 11
`
`5
`
`

`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 5 0f 8
`
`US 2009/0161654 A1
`
`FIG. ?
`
`
`
`6
`
`

`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 6 0f 8
`
`US 2009/0161654 A1
`
`FIG.8
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`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 7 0f 8
`
`US 2009/0161654 A1
`
`700
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`

`

`Patent Application Publication
`
`Jun. 25, 2009 Sheet 8 0f 8
`
`US 2009/0161654 A1
`
`Receive Module
`
`Evaluation Module
`
`
`
`
`
`Calculation Medule
`
`20
`
`FIG. l2
`
`9
`
`

`

`US 2009/0161654 A1
`
`Jun. 25, 2009
`
`SYSTEM AND METHOD FOR UPLINK
`TIMING SYNCHRONIZATION
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] The present application claims priority to US. 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 reproduced in its entirety.
`
`BACKGROUND
`
`In traditional 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-
`ment has been introduced that can provide services that were
`not possible previously. This advanced network access equip-
`ment might include, for example, an enhanced node-B (eNB)
`rather than a base station or other systems and devices that are
`more highly evolved than the equivalent equipment in a tra-
`ditional wireless telecommunications system. Such advanced
`or next generation equipment is typically referred to as long-
`term evolution (LTE) equipment. For LTE equipment, the
`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.
`
`Services that might be provided by LTE-based
`[0004]
`equipment can include broadcasts or multicasts of television
`programs, streaming video, streaming audio, and other mul-
`timedia content. Such services are commonly referred to as
`multimedia broadcast multicast
`services
`(MBMS). An
`MBMS might be transmitted throughout a single cell or
`throughout several contiguous or overlapping cells. The
`MBMS may be communicated from an eNB to a UE using
`point-to-point (PTP) communication or point-to-multipoint
`(PTM) communication.
`[0005]
`In wireless communication systems, transmission
`from the network access equipment (e.g., eNB) to the UE is
`referred to as a downlink transmission. Communication from
`
`the UE to the network access equipment is 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
`always have data to transmit.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For a more complete understanding of this disclo-
`[0006]
`sure, reference is now made to the following brief description,
`
`taken in connection with the accompanying drawings and
`detailed description, wherein like reference numerals repre-
`sent like parts.
`[0007]
`FIG. 1 is an illustration ofa cellular network accord-
`ing to an embodiment of the disclosure.
`[0008]
`FIG. 2 is an illustration ofa cell in a cellular network
`according to an embodiment of the disclosure.
`[0009]
`FIG. 3 is an illustration of a one possible uplink
`transmission channel for LTE.
`
`FIG. 4 is a timing diagram.
`[0010]
`FIG. 5 is a flow chart corresponding to one UE
`[0011]
`embodiment.
`
`FIG. 6 is a flow chart corresponding to one network
`[0012]
`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 of the disclosure.
`
`FIG. 8 is a block diagram of a mobile device oper-
`[0014]
`able for some of the various embodiments of the disclosure.
`
`FIG. 9 is a diagram of a software environment that
`[0015]
`may be implemented on a mobile device operable for some of
`the various embodiments of the disclosure.
`
`FIG. 10 is an exemplary general purpose computer
`[0016]
`according to one embodiment of the present disclosure.
`[0017]
`FIG. 11 is an exemplary diagram of modules in the
`UE.
`
`FIG. 12 is an exemplary diagram of modules in the
`[0018]
`network access equipment.
`
`DETAILED DESCRIPTION
`
`It should be understood at 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 known or in existence. The
`disclosure should in no way be limited to the illustrative
`implementations, drawings, and techniques illustrated below,
`including the exemplary designs and implementations illus-
`trated and described herein, but may be modified within the
`scope of the appended claims along with their full scope of
`equivalents.
`[0020]
`FIG. 1 illustrates an exemplary cellular network 100
`according to an embodiment of the disclosure. The cellular
`network 100 may include a plurality ofcells 1021, 1022, 1023,
`1024, 1025, 1026, 1027, 1028, 1029, 10210, 10211, 10212,
`10213, and 102 14 (collectively referred to as cells 102). As is
`apparent to persons of ordinary skill in the art, each of the
`cells 102 represents a coverage area for providing cellular
`services of the cellular network 100 through communication
`from a network access equipment (e.g., eNB). While the cells
`102 are depicted as having non-overlapping coverage areas,
`persons of ordinary skill in the art will recognize that one or
`more of the cells 102 may have partially overlapping cover-
`age with adjacent cells. In addition, while a particular number
`of the cells 102 are depicted, persons of ordinary skill in the
`art will recognize that a larger or smaller number of the cells
`102 may be included in the cellular network 100.
`[0021] One or more UEs 10 may be present 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 may be present in each of the
`cells 102. A network access equipment 20 in each of the cells
`102 performs functions similar to those of a traditional base
`station. That is, the network access equipments 20 provide a
`
`10
`
`10
`
`

`

`US 2009/0161654 A1
`
`Jun. 25, 2009
`
`radio link between the UEs 10 and other components in a
`telecommunications network. While the network access
`
`equipment 20 is shown only 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 may also be present in
`the cellular network 100 to oversee some of 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 present in 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 the cells.
`[0023]
`In each cell, the transmissions from the network
`access equipment 20 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
`number ofdifferent 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 frame is 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 by at
`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 same fre-
`quency bandwidth as a resource block. A UE may use one or
`all of those frequency blocks depending on the transmission
`bandwidth selected. The UE may also 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 where in 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 NACK is sent on the PUCCH 211 by the UE to the
`eNB to indicate whether a packet transmitted from the eNB
`
`was received at that UE. The physical uplink shared channel
`(PUSCH) is used to send user data.
`[0026] The above description of the uplink channel is 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. One possible 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 may instruct 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 of net-
`work resources and a drain on the UE battery if unnecessary.
`Alternatively, the UE 10 may choose not to send the timing
`reference signal transmission ifthe UE 10 determines that the
`UE 10 will be sending data in the same time interval that the
`UE 10 would have sent the 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 UE transmits its CAZAC sequence.
`[0028]
`FIG. 5 illustrates an embodiment of such a method
`for uplink timing reference signal transmission in a 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
`determine if there is uplink data to 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 be sent, at block 259 the
`UE send the 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 equipment 20 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 determines that no timing reference signal instruction was
`received, then at block 267 the network access equipment will
`calculate an uplink timing alignment adjustment based upon
`the data received. For example, in an LTE system, the data
`comprises a DM RS. The eNB can then use the DM RS to
`calculate the uplink timing alignment adjustment. Ifhowever,
`the network access equipment determines that an uplink tim-
`
`11
`
`11
`
`

`

`US 2009/0161654 A1
`
`Jun. 25, 2009
`
`ing reference signal transmission was received, at block 265
`the network access equipment calculates the uplink timing
`alignment adjustment based upon the uplink timing reference
`signal transmission received.
`[0030]
`In order to carry out the above process, the UE 10
`comprises a processor capable of performing the above pro-
`cess. For simplicity, the different functions have been broken
`out into different modules. These modules may be imple-
`mented separately or together. Further, these modules may be
`implemented in hardware, software, or some combination.
`Finally, these modules may reside in different portions of the
`UE memory. As illustrated in FIG. 11, the UE processor
`comprises a receive module 801, a determination module
`803, an evaluation module 805 and a transmission module
`807. The receive module 801 receives the uplink timing ref-
`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 same as the time interval for transmitting the data,
`the evaluation module 805 informs the transmission module
`
`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 time interval in the message where it 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. If an 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 upon the 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 embodiment ofthe UE 10. The UE 10 is operable
`for implementing aspects of the disclosure, but the disclosure
`should not be limited to these implementations. Though illus-
`trated as a mobile phone, the UE 10 may take various forms
`including a wireless handset, a pager, a personal digital assis-
`tant (PDA), a portable computer, a tablet computer, or a
`laptop computer. Many suitable devices combine some or all
`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
`
`10 may be a portable, laptop or other computing device. The
`UE 10 may support specialized activities such as gaming,
`inventory control, job control, and/or task management func-
`tions, and so on.
`[0033] The UE 10 includes a display 402. The UE 10 also
`includes a touch-sensitive surface, a keyboard or other input
`keys generally referred as 404 for input by a user. The key-
`board may be a full or reduced alphanumeric keyboard such
`as QWERTY, Dvorak, AZERTY, and sequential types, or a
`traditional numeric keypad with alphabet letters associated
`with a telephone keypad. The input keys may include a track-
`wheel, an exit or escape key, a trackball, and other naviga-
`tional or functional keys, which may be inwardly depressed to
`provide further input function. The UE 10 may present
`options for the user to select, controls for the user to actuate,
`and/or cursors or other indicators for the user to direct.
`
`[0034] The UE 10 may further accept data entry from the
`user, including numbers to dial or various parameter values
`for configuring the operation of the UE 10. The UE 10 may
`further execute one or more software or firmware applications
`in response to user commands. These applications may con-
`figure the UE 10 to perform various customized functions in
`response to user interaction. Additionally, the UE 10 may be
`programmed and/or configured over-the-air, for example
`from a wireless base station, a wireless access point, or a peer
`UE 10.
`
`[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 may be obtained via 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 shown on the display 402 . Altemately, the
`UE 10 may access the network 400 through a peer UE 10
`acting as an intermediary, in a relay type or hop type of
`connection.
`
`FIG. 8 shows a block diagram ofthe UE 10. While a
`[0036]
`variety of known components of UEs 10 are depicted, in an
`embodiment a subset of the listed components and/or addi-
`tional components not listed may be included in the UE 10.
`The UE 10 includes a digital signal processor (DSP) 502 and
`a memory 504. As shown, the UE 10 may further include an
`antenna and front 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, a keypad 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 may include another kind of display
`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 502 itself. In addition to the embedded
`
`software or 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 and front 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 network or from a peer UE 10. In an embodiment, the
`antenna and front 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 overcome difiicult channel conditions and/or
`
`increase channel throughput. The antenna and front end unit
`506 may include antenna tuning and/or impedance matching
`components, RF power amplifiers, and/or low noise amplifi-
`ers
`
`[0039] The RF transceiver 508 provides frequency shifting,
`converting received RF signals to baseband and converting
`baseband transmit 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
`purposes of clarity, the description here separates the descrip-
`tion of this signal processing from the RF and/or radio stage
`and conceptually allocates that signal processing to the ana-
`log baseband processing unit 510 and/or the DSP 502 or other
`central processing unit. In some embodiments, the RF Trans-
`ceiver 508, portions of the Antenna and Front End 506, and
`the analog baseband processing unit 510 may be combined in
`one or more processing units and/or application specific inte-
`grated circuits (ASICs).
`[0040] The analog baseband processing unit 510 may pro-
`vide various analog processing of inputs and outputs, for
`example analog processing of inputs from the microphone
`512 and the headset 516 and outputs to the earpiece 514 and
`the headset 516. To that end, the analog baseband processing
`unit 510 may have ports for connecting to the built-in micro-
`phone 512 and the earpiece speaker 514 that enable the UE 10
`to be used as a cell phone. The analog baseband processing
`unit 51 0 may further include a port for connecting to a headset
`or other hands-free microphone and speaker configuration.
`The analog baseband processing unit 510 may provide digi-
`tal-to-analog conversion in one signal direction and analog-
`to-digital conversion in the opposing signal direction. In some
`embodiments, at least some of the functionality of the analog
`baseband processing unit 510 may be provided by digital
`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/
`
`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 combinations of signal processing
`functions may be performed by the DSP 502.
`[0042] The DSP 502 may communicate with a wireless
`network via the analog baseband processing unit 510. In some
`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. Among the inter-
`faces may be the USB interface 522 and the short range
`wireless communication sub-system 524. The USB interface
`522 may be used to charge the UE 10 and may also 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
`802.1 1 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.
`
`[0043] The input/output interface 518 may further connect
`the DSP 502 to the alert 526 that, when triggered, causes the
`UE 10 to provide a notice to the user, for example, by ringing,
`playing a melody, or vibrating. The alert 526 may serve as a
`mechanism for alerting the user to any of various events such
`as an incoming call, a new text message, and an appointment
`reminder by silently vibrating, or by playing a specific pre-
`assigned melody for a particular caller.
`[0044] The keypad 528 couples to the DSP 502 via the
`interface 518 to provide one mechanism for the user to make
`selections, enter information, and otherwise provide input to
`the UE 10. The keyboard 528 may be a full or reduced alpha-
`numeric keyboard such as QWERTY, Dvorak, AZERTY and
`sequential types, or a traditional numeric keypad with alpha-
`bet letters associated with a telephone keypad. The input keys
`may include a trackwheel, an exit or escape key, a trackball,
`and other navigational or functional keys, which may be
`inwardly depressed to provide further input function. Another
`input mechanism may be the LCD 530, which may include
`touch screen capability and also display text and/or graphics
`to the user. The LCD controller 532 couples the DSP 502 to
`the LCD 530.
`
`[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