Patent Publication Number: US-2019182834-A1

Title: Timing advance adjustment communication

Description:
FIELD 
     The subject matter disclosed herein relates generally to wireless communications and more particularly relates to timing advance adjustment communication. 
     BACKGROUND 
     The following abbreviations are herewith defined, at least some of which are referred to within the following description: Third Generation Partnership Project (“3GPP”), Positive-Acknowledgment (“ACK”), Binary Phase Shift Keying (“BPSK”), Clear Channel Assessment (“CCA”), Cyclic Prefix (“CP”), Channel State Information (“CSI”), Common Search Space (“CSS”), Downlink Control Information (“DCI”), Downlink (“DL”), Downlink Pilot Time Slot (“DwPTS”), Enhanced Clear Channel Assessment (“eCCA”), Evolved Node B (“eNB”), European Telecommunications Standards Institute (“ETSI”), Frame Based Equipment (“FBE”), Frequency Division Duplex (“FDD”), Frequency Division Multiple Access (“FDMA”), Guard Period (“GP”), Hybrid Automatic Repeat Request (“HARQ”), Licensed Assisted Access (“LAA”), Load Based Equipment (“LBE”), Listen-Before-Talk (“LBT”), Long Term Evolution (“LTE”), Machine Type Communication (“MTC”), Multiple Input Multiple Output (“MIMO”), Negative-Acknowledgment (“NACK”) or (“NAK”), Orthogonal Frequency Division Multiplexing (“OFDM”), Primary Cell (“PCell”), Physical Broadcast Channel (“PBCH”), Physical Downlink Control Channel (“PDCCH”), Physical Downlink Shared Channel (“PDSCH”), Physical Hybrid ARQ Indicator Channel (“PHICH”), Physical Random Access Channel (“PRACH”), Physical Resource Block (“PRB”), Physical Uplink Control Channel (“PUCCH”), Physical Uplink Shared Channel (“PUSCH”), Quality of Service (“QoS”), Quadrature Phase Shift Keying (“QPSK”), Radio Resource Control (“RRC”), Random Access Procedure (“RACH”), Resource Spread Multiple Access (“RSMA”), Round Trip Time (“RTT”), Receive (“RX”), Scheduling Request (“SR”), Single Carrier Frequency Division Multiple Access (“SC-FDMA”), Secondary Cell (“SCell”), Shared Channel (“SCH”), Signal-to-Interference-Plus-Noise Ratio (“SINR”), System Information Block (“SIB”), Transport Block (“TB”), Transport Block Size (“TBS”), Time-Division Duplex (“TDD”), Time Division Multiplex (“TDM”), Transmission Time Interval (“TTI”), Transmit (“TX”), Uplink Control Information (“UCI”), User Entity/Equipment (Mobile Terminal) (“UE”), Uplink (“UL”), Universal Mobile Telecommunications System (“UMTS”), Uplink Pilot Time Slot (“UpPTS”), Ultra-reliable and Low-latency Communications (“URLLC”), and Worldwide Interoperability for Microwave Access (“WiMAX”). As used herein, “HARQ-ACK” may represent collectively the Positive Acknowledge (“ACK”) and the Negative Acknowledge (“NAK”). ACK means that a TB is correctly received while NAK means a TB is erroneously received. 
     In certain wireless communications networks, to avoid resource collision in uplink communication, the networks adopt orthogonal multiple access (“OMA”). The networks may also use scheduling-based uplink transmission so that the orthogonal resources are assigned for different UEs. Moreover, any uplink communication (e.g., except PRACH) may be scheduled and/or controlled by an eNB. As compared to OMA, non-orthogonal multiple access (“NOMA”) may support signal superposition in an orthogonal resource. Accordingly, NOMA may enhance spectrum utilization efficiency, such as in cases of overloaded transmission. Moreover, since NOMA may separate superposed signals at the receiver by using more advanced algorithms, NOMA may support reliable and low latency grant-free transmission. Such transmission may be used for massive MTC and/or URLLC. 
     In some configurations, there may be no clear difference between autonomous, grant-free, and/or contention based UL transmission. In certain configurations, contention based UL transmission may include autonomous, grant-free, and/or grant-less transmission. 
     For contention based UL transmission without any timing advance (“TA”) assistance, different UE signals transmitted in a subframe may arrive at a serving eNB with different timing offsets. In OFDM based waveforms, if timing offsets between UEs is larger than the CP, superposed signals of multiple UEs on a resource may increase the eNB blind detection complexity due to interference. 
     In certain NOMA schemes, UL synchronization support may be used (e.g., timing offsets between UEs may be within a cyclic prefix). In some configurations, a single tone based RSMA may support asynchronous cases. However, single tone based RSMA may not efficiently solve the problem of multi-path channel and integration with MIMO. Moreover, asynchronous NOMA may use a complicated receiver. 
     BRIEF SUMMARY 
     Apparatuses for timing advance adjustment communication are disclosed. Methods and systems also perform the functions of the apparatus. In one embodiment, the apparatus includes a transmitter that transmits a first signal to a first device for indicating a first field within a control channel. In such an embodiment, the first field is used to indicate first timing advance adjustment information for the first device. 
     In one embodiment, the transmitter transmits a second signal to a second device for indicating a second field within the control channel. In such an embodiment, the second field is used to indicate second timing advance adjustment information for the second device. In a further embodiment, the apparatus includes a receiver that receives a sequence from the first device. In such an embodiment, the sequence is a device specific sequence that distinguishes the first device from another device. In some embodiments, the sequence is generated based on an identification of the first device. In certain embodiments, the sequence occupies one symbol within a transmission time interval. 
     In some embodiments, the first device transmits data with the sequence in a transmission time interval. In various embodiments, the data and the sequence have a same bandwidth in a frequency domain. In certain embodiments, the first signal indicates the sequence. In one embodiment, the first signal indicates a resource pool for the first device to transmit the sequence. In some embodiments, the first device transmits the sequence on a resource of the resource pool. In various embodiments, the resource pool is shared by multiple devices. 
     A method for timing advance adjustment communication, in one embodiment, includes transmitting a first signal to a first device for indicating a first field within a control channel. In such an embodiment, the first field is used to indicate first timing advance adjustment information for the first device. 
     In one embodiment, an apparatus includes a receiver that receives timing advance adjustment information in a field within a control channel. 
     In one embodiment, the receiver receives a signal indicating the field within the control channel. In a further embodiment, the signal indicates a sequence. In some embodiments, the signal indicates a resource pool for transmitting a sequence. In certain embodiments, the apparatus includes a processor that generates a sequence and a transmitter that transmits the sequence based on the timing advance adjustment information. In such embodiments, the sequence is a device specific sequence that distinguishes the apparatus from another device. In some embodiments, the sequence is generated based on an identification of the apparatus. 
     In various embodiments, the transmitter transmits the sequence on a resource of a resource pool. In one embodiment, the resource pool is shared by multiple devices. In certain embodiments, the sequence occupies one symbol within a transmission time interval. In some embodiments, the transmitter transmits data with the sequence in a transmission time interval. In various embodiments, the data and the sequence have a same bandwidth in a frequency domain. 
     A method for timing advance adjustment communication, in one embodiment, includes receiving timing advance adjustment information in a field within a control channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1  is a schematic block diagram illustrating one embodiment of a wireless communication system for timing advance adjustment communication; 
         FIG. 2  is a schematic block diagram illustrating one embodiment of an apparatus that may be used for timing advance adjustment communication; 
         FIG. 3  is a schematic block diagram illustrating one embodiment of an apparatus that may be used for timing advance adjustment communication; 
         FIG. 4  illustrates one embodiment of communications for timing advance adjustment communication; 
         FIG. 5  illustrates one embodiment of uplink transmissions; 
         FIG. 6  illustrates another embodiment of uplink transmissions; 
         FIG. 7  is a schematic flow chart diagram illustrating one embodiment of a method for timing advance adjustment communication; and 
         FIG. 8  is a schematic flow chart diagram illustrating another embodiment of a method for timing advance adjustment communication. 
     
    
    
     DETAILED DESCRIPTION 
     As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non-transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code. 
     Certain of the functional units described in this specification may be labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. 
     Modules may also be implemented in code and/or software for execution by various types of processors. An identified module of code may, for instance, include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may include disparate instructions stored in different locations which, when joined logically together, include the module and achieve the stated purpose for the module. 
     Indeed, a module of code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different computer readable storage devices. Where a module or portions of a module are implemented in software, the software portions are stored on one or more computer readable storage devices. 
     Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. 
     More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc read-only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. 
     Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the “C” programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including 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). 
     Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise. 
     Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment. 
     Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. These code 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 schematic flowchart diagrams and/or schematic block diagrams block or blocks. 
     The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the schematic flowchart diagrams and/or schematic block diagrams block or blocks. 
     The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The schematic flowchart diagrams and/or schematic block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods and program products according to various embodiments. In this regard, each block in the schematic flowchart diagrams and/or schematic block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s). 
     It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures. 
     Although various arrow types and line types may be employed in the flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code. 
     The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements. 
       FIG. 1  depicts an embodiment of a wireless communication system  100  for timing advance adjustment communication. In one embodiment, the wireless communication system  100  includes remote units  102  and base units  104 . Even though a specific number of remote units  102  and base units  104  are depicted in  FIG. 1 , one of skill in the art will recognize that any number of remote units  102  and base units  104  may be included in the wireless communication system  100 . 
     In one embodiment, the remote units  102  may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units  102  include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units  102  may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, UE, user terminals, a device, or by other terminology used in the art. The remote units  102  may communicate directly with one or more of the base units  104  via UL communication signals. 
     The base units  104  may be distributed over a geographic region. In certain embodiments, a base unit  104  may also be referred to as an access point, an access terminal, a base, a base station, a Node-B, an eNB, a Home Node-B, a relay node, a device, or by any other terminology used in the art. The base units  104  are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units  104 . The radio access network is generally communicably coupled to one or more core networks, which may be coupled to other networks, like the Internet and public switched telephone networks, among other networks. These and other elements of radio access and core networks are not illustrated but are well known generally by those having ordinary skill in the art. 
     In one implementation, the wireless communication system  100  is compliant with the LTE of the 3GPP protocol, wherein the base unit  104  transmits using an OFDM modulation scheme on the DL and the remote units  102  transmit on the UL using a SC-FDMA scheme. More generally, however, the wireless communication system  100  may implement some other open or proprietary communication protocol, for example, WiMAX, among other protocols. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. 
     The base units  104  may serve a number of remote units  102  within a serving area, for example, a cell or a cell sector via a wireless communication link. The base units  104  transmit DL communication signals to serve the remote units  102  in the time, frequency, and/or spatial domain. 
     In one embodiment, a base unit  104  may transmit a first signal to a first device for indicating a first field within a control channel. In such an embodiment, the first field may be used to indicate first timing advance adjustment information for the first device. Accordingly, a base unit  104  may receive timing advance adjustment information. 
     In another embodiment, a remote unit  102  may receive timing advance adjustment information in a field within a control channel. Accordingly, a remote unit  102  may receive timing advance adjustment information. 
       FIG. 2  depicts one embodiment of an apparatus  200  that may be used for timing advance adjustment communication. The apparatus  200  includes one embodiment of the remote unit  102 . Furthermore, the remote unit  102  may include a processor  202 , a memory  204 , an input device  206 , a display  208 , a transmitter  210 , and a receiver  212 . In some embodiments, the input device  206  and the display  208  are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit  102  may not include any input device  206  and/or display  208 . In various embodiments, the remote unit  102  may include one or more of the processor  202 , the memory  204 , the transmitter  210 , and the receiver  212 , and may not include the input device  206  and/or the display  208 . 
     The processor  202 , in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor  202  may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor  202  executes instructions stored in the memory  204  to perform the methods and routines described herein. The processor  202  is communicatively coupled to the memory  204 , the input device  206 , the display  208 , the transmitter  210 , and the receiver  212 . In certain embodiments, the processor  202  may generating a sequence for transmissions. 
     The memory  204 , in one embodiment, is a computer readable storage medium. In some embodiments, the memory  204  includes volatile computer storage media. For example, the memory  204  may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory  204  includes non-volatile computer storage media. For example, the memory  204  may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory  204  includes both volatile and non-volatile computer storage media. In some embodiments, the memory  204  stores data relating to an indication to be provided to another device. In some embodiments, the memory  204  also stores program code and related data, such as an operating system or other controller algorithms operating on the remote unit  102 . 
     The input device  206 , in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device  206  may be integrated with the display  208 , for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device  206  includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device  206  includes two or more different devices, such as a keyboard and a touch panel. 
     The display  208 , in one embodiment, may include any known electronically controllable display or display device. The display  208  may be designed to output visual, audible, and/or haptic signals. In some embodiments, the display  208  includes an electronic display capable of outputting visual data to a user. For example, the display  208  may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the display  208  may include a wearable display such as a smart watch, smart glasses, a heads-up display, or the like. Further, the display  208  may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like. 
     In certain embodiments, the display  208  includes one or more speakers for producing sound. For example, the display  208  may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the display  208  includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the display  208  may be integrated with the input device  206 . For example, the input device  206  and display  208  may form a touchscreen or similar touch-sensitive display. In other embodiments, the display  208  may be located near the input device  206 . 
     The transmitter  210  is used to provide UL communication signals to the base unit  104  and the receiver  212  is used to receive DL communication signals from the base unit  104 . In one embodiment, the transmitter  210  is used to transmit a sequence. In certain embodiments, the receiver  212  may be used to receive timing advance adjustment information in a field within a control channel. Although only one transmitter  210  and one receiver  212  are illustrated, the remote unit  102  may have any suitable number of transmitters  210  and receivers  212 . The transmitter  210  and the receiver  212  may be any suitable type of transmitters and receivers. In one embodiment, the transmitter  210  and the receiver  212  may be part of a transceiver. 
       FIG. 3  depicts one embodiment of an apparatus  300  that may be used for timing advance adjustment communication. The apparatus  300  includes one embodiment of the base unit  104 . Furthermore, the base unit  104  may include a processor  302 , a memory  304 , an input device  306 , a display  308 , a transmitter  310 , and a receiver  312 . As may be appreciated, the processor  302 , the memory  304 , the input device  306 , and the display  308  may be substantially similar to the processor  202 , the memory  204 , the input device  206 , and the display  208  of the remote unit  102 , respectively. 
     The transmitter  310  may also be used to transmit a first signal to a first device for indicating a first field within a control channel. In such an embodiment, the first field is used to indicate first timing advance adjustment information for the first device. The receiver  312  is used to receive a sequence. Although only one transmitter  310  and one receiver  312  are illustrated, the base unit  104  may have any suitable number of transmitters  310  and receivers  312 . The transmitter  310  and the receiver  312  may be any suitable type of transmitters and receivers. In one embodiment, the transmitter  310  and the receiver  312  may be part of a transceiver. 
       FIG. 4  illustrates one embodiment of communications  400  for timing advance adjustment communication. Specifically, communications  400  between a UE  402  and an eNB  404  are illustrated. A first communication  406  may include configuration information transmitted from the eNB  404  and received by the UE  402 . In some embodiments, the configuration information is indicated by RRC signaling. The configuration information may include an indication of: a first field within a control channel used to indicate first timing advance adjustment information for a first device; a second field within the control channel used to indicate second timing advance adjustment information for a second device; a sequence to be used for transmissions; a resource to be used for transmissions; and/or a resource pool to be used for transmissions. 
     A length of the first and/or second field (e.g., number of bits) may be fixed in a specification or determined by the eNB  404 . In certain embodiments, the eNB  404  may schedule a DL transmission and indicate timing advance adjustment information in the scheduled DL transmission. The scheduled DL transmission may include the timing advance adjustment information in a medium access control (“MAC”) element. In some embodiments, the scheduled DL transmission may occur infrequently, such as when used with MTC. 
     In certain embodiments, the sequence may be a device (e.g., UE, remote unit  102 ) specific sequence so that each device that communicates with the eNB  404  has a unique sequence. Accordingly, the eNB  404  may be able to determine which communications from a particular device (e.g., distinguish between different devices). Specifically, the sequence may be a device specific sequence for the UE  402 . In one embodiment, the sequence may be a constant amplitude zero autocorrelation (“CAZAC”) sequence which may facilitate a low peak to average power ratio (“PAPR”). In certain embodiments, the sequence may be mapped by device identification, such as by a one-to-one mapping relationship. 
     The first communication  406  may configure a resource pool for the device specific sequence transmission. A resource period, a TTI offset, an occupied frequency bandwidth, and/or frequency position may be indicated by the first communication  408 . 
     A second communication  408  includes the sequence being transmitted from the UE  402  (e.g., remote unit  102 ) and received by the eNB  404  (e.g., base unit  104 ). In various embodiments, the UE  402  may generate the sequence and transmit the sequence based on information from the first communication  406 . In some embodiments, the sequence may be generated based on an identification of the UE  402 . In certain embodiments, the sequence may occupy one symbol (e.g., have one symbol duration). In various embodiments, the sequence may occupy one or more symbols. In such embodiments, a concrete length of the sequence may be defined by the first communication  406 . In certain embodiments, a device specific sequence may be transmitted in a specific resource without data transmission following the device specific sequence. In one embodiment, the resource pool is device specific. In another embodiment, the resource pool may be shared by a device group. Due to good cross-correlation of a device specific sequence, the eNB  404  may separate each device&#39;s sequence if multiple devices transmit their respective sequence in the same resource simultaneously. 
     For contention based UL data transmission, the eNB  404  may not be aware of which device is transmitting data in one TTI so that it has to assume the existence of each device from the received signals then use successive interference cancellation (“SIC”) or message passing algorithm (“MPA”) algorithms to decode the devices one by one. Since a device specific sequence is unique within one cell, it may implicitly contain the device identification information. In certain embodiments, there may be three eNB  404  behaviors for responding to device specific sequence transmissions in embodiments involving contention based UL transmissions. 
     A first behavior is that the eNB  404  may determine the existence of one device by performing correlation of a device specific sequence with a received signal. In this way, blind detection complexity at the eNB  404  may be reduced. A second behavior is that the eNB  404  may determine the timing advance for one device after detecting the device&#39;s specific sequence which may indicate timing advance adjustment information in a DL channel. A third behavior is that the eNB  404  may know that the data following a device specific sequence is transmitted from the same device and may combine the received data with a previous version for retransmission combination. Accordingly, signaling overhead for a device may be reduced. 
     A third communication  410  may include data transmitted from the UE  402  to the eNB  404 . In one embodiment, the data may be transmitted in a same TTI as the second communication  408 . In another embodiment, a first portion of data may be transmitted in a first TTI as the second communication  408 , and a second portion of data may be transmitted in one or more additional TTIs that follow the first TTI. In some embodiments, the third communication  410  and the second communication  408  may have the same bandwidth in the frequency domain. 
     A fourth communication  412  includes timing advance adjustment information from the eNB  404  to the UE  402  that may be transmitted in a field previously indicated as including timing advance adjustment information for the UE  402 . The timing advance adjustment information may be determined by the eNB  404 . 
     By performing transmissions as described herein a remove unit  102  specific sequence may be transmitted for configurations using contention based UL transmission. Moreover, common DCI information may be used for UL timing advance adjustment information for configurations using contention based UL transmission. As presented herein, UL synchronization may be maintained to facilitate interference at a base unit  104 , and/or UL control signaling overhead may be reduced. 
       FIG. 5  illustrates one embodiment of uplink transmissions  500 . Specifically, a UE specific sequence  502  (e.g., device specific sequence) is transmitted followed by data  504 . The UE specific sequence  502  and the data  504  are transmitted in a same TTI  506 . In some embodiments, no data  504  is transmitted after the UE specific sequence  502  is transmitted. Accordingly, in such embodiments, only the UE specific sequence  502  is transmitted in the TTI  506 . 
       FIG. 6  is a schematic block diagram illustrating another embodiment of uplink transmissions  600 . Specifically, a UE specific sequence  602  (e.g., device specific sequence) is transmitted followed by data  604 . The UE specific sequence  602  and the data  604  are transmitted in a first TTI  606 . Data  608  may be transmitted in a second TTI  608  following the first TTI  606 . Moreover, data  612  may be transmitted in a third TTI  614  following the second TTI  610 . As may be appreciated, any amount of data may be transmitted in TTIs following the first TTI  606 . Moreover, each of the TTIs may have a same bandwidth in a frequency domain. 
       FIG. 7  is a schematic flow chart diagram illustrating one embodiment of a method  700  for timing advance adjustment communication. In some embodiments, the method  700  is performed by an apparatus, such as the base unit  104 . In certain embodiments, the method  700  may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like. 
     The method  700  may include transmitting  702  a first signal a first signal to a first device for indicating a first field within a control channel. In such an embodiment, the first field is used to indicate first timing advance adjustment information for the first device. 
     In one embodiment, the method  700  may include transmitting a second signal to a second device for indicating a second field within the control channel. In such an embodiment, the second field may be used to indicate second timing advance adjustment information for the second device. In a further embodiment, the method  700  may include receiving a sequence from the first device. In such an embodiment, the sequence may be a device specific sequence that distinguishes the first device from another device. In some embodiments, the sequence is generated based on an identification of the first device. In certain embodiments, the sequence occupies one symbol within a transmission time interval. 
     In some embodiments, the first device transmits data with the sequence in a transmission time interval. In various embodiments, the data and the sequence have a same bandwidth in a frequency domain. In certain embodiments, the first signal indicates the sequence. In one embodiment, the first signal indicates a resource pool for the first device to transmit the sequence. In some embodiments, the first device transmits the sequence on a resource of the resource pool. In various embodiments, the resource pool is shared by multiple devices. 
       FIG. 8  is a schematic flow chart diagram illustrating one embodiment of a method  800  for timing advance adjustment communication. In some embodiments, the method  800  is performed by an apparatus, such as the remote unit  102 . In certain embodiments, the method  800  may be performed by a processor executing program code, for example, a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like. 
     The method  800  may include receiving  802  timing advance adjustment information in a field within a control channel. 
     In one embodiment, the method  800  includes receiving a signal indicating the field within the control channel. In a further embodiment, the signal indicates a sequence. In some embodiments, the signal indicates a resource pool for transmitting a sequence. In certain embodiments, the method  800  includes generating a sequence and transmitting the sequence based on the timing advance adjustment information. In such embodiments, the sequence is a device specific sequence that distinguishes a device from another device. In some embodiments, the sequence is generated based on an identification of the device. 
     In various embodiments, the method  800  includes transmitting the sequence on a resource of a resource pool. In one embodiment, the resource pool is shared by multiple devices. In certain embodiments, the sequence occupies one symbol within a transmission time interval. In some embodiments, the method  800  includes transmitting data with the sequence in a transmission time interval. In various embodiments, the data and the sequence have a same bandwidth in a frequency domain. 
     Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.