Patent Description:
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"), Device-to-Device ("D2D"), 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"), Identification ("ID"), Licensed Assisted Access ("LAA"), Load Based Equipment ("LBE"), Listen-Before-Talk ("LBT"), Long Term Evolution ("LTE"), Negative-Acknowledgment ("NACK") or ("NAK"), Orthogonal Cover Code ("OCC"), 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"), Pedestrian-to-Vehicle ("P2V"), Quality of Service ("QoS"), Quadrature Phase Shift Keying ("QPSK"), Radio Resource Control ("RRC"), Random Access Procedure ("RACH"), 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"), Transmit ("TX"), Uplink Control Information ("UCI"), User Entity/Equipment (Mobile Terminal) ("UE"), Uplink ("UL"), Universal Mobile Telecommunications System ("UMTS"), Uplink Pilot Time Slot ("UpPTS"), Vehicle-to-Pedestrian ("V2P"), Vehicle-to-Vehicle ("V2V"), Vehicle-to-Everything ("V2X"), 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, D2D communication may occur between two different UEs. For example, in some networks V2P and/or P2V communication may occur. In such networks, certain UEs may transmit and/or receive excessive communications. Such transmissions and/or receptions may use a large amount of battery and/or other resources.

R1-<NUM> is a 3GPP discussion document titled "<NPL>. This document addresses device-to-device communication and issues such as how a UE gets synchronization before transmitting and receiving in a carrier other than PCell.

<CIT> discloses a method for wireless communication in connection with communication of safety messages by a device on behalf of other devices in a group.

The invention is defined and limited by the scope of the appended claims. Claim <NUM> defines a remote unit, claim <NUM> defines a method in a remote unit. In the following description, any embodiment referred to and not falling within the scope of the appended claims, is merely an example useful for the understanding of the invention.

Apparatuses for configuring device-to-device transmission are disclosed.

As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a remote unit and a method.

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.

<FIG> depicts an embodiment of a wireless communication system <NUM> for device-to-device transmission. In one embodiment, the wireless communication system <NUM> includes remote units <NUM> and base units <NUM>. Even though a specific number of remote units <NUM> and base units <NUM> are depicted in <FIG>, one of skill in the art will recognize that any number of remote units <NUM> and base units <NUM> may be included in the wireless communication system <NUM>.

Moreover, the remote units <NUM> may be referred to as subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, UE, user terminals, a device, a vehicle UE, a pedestrian UE, or by other terminology used in the art. Furthermore, the remote units <NUM> may communicate directly with other remote units <NUM>.

The base units <NUM> may be distributed over a geographic region. In certain embodiments, a base unit <NUM> 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 <NUM> are generally part of a radio access network that includes one or more controllers communicably coupled to one or more corresponding base units <NUM>.

In one implementation, the wireless communication system <NUM> is compliant with the LTE of the 3GPP protocol, wherein the base unit <NUM> transmits using an OFDM modulation scheme on the DL and the remote units <NUM> transmit on the UL using a SC-FDMA scheme. More generally, however, the wireless communication system <NUM> may implement some other open or proprietary communication protocol, for example, WiMAX, among other protocols.

In one embodiment, a base unit <NUM> may generate a first signal indicating a first sequence and a first resource pool. In such an embodiment, transmission of the first sequence within the first resource pool indicates a behavior of a first device that transmits the transmission of the first sequence, and the first resource pool is configured for use by multiple devices. In some embodiments, the base unit <NUM> may transmitting the first signal to the first device. Accordingly, a base unit <NUM> may configure device-to-device transmission.

In another embodiment, a remote unit <NUM> (e.g., pedestrian UE ("P-UE)) may generate a sequence. The remote unit <NUM> may select a resource from a resource pool. The remote unit <NUM> may also transmit the sequence on the resource. The transmission of the sequence on the resource may indicate a behavior of the remote unit <NUM>. Accordingly, a remote unit <NUM> may transmit device-to-device transmissions.

In certain embodiments, a remote unit <NUM> (e.g., vehicle UE ("V-UE")) may, on each resource within a resource pool, detect whether a sequence is transmitted. Transmission of the sequence within the resource pool may indicate a behavior of a device that transmits the transmission of the sequence. Accordingly, a remote unit <NUM> may receive device-to-device transmissions.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for device-to-device transmission. The apparatus <NUM> includes one embodiment of the remote unit <NUM>. Furthermore, the remote unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. In some embodiments, the input device <NUM> and the display <NUM> are combined into a single device, such as a touchscreen. In certain embodiments, the remote unit <NUM> may not include any input device <NUM> and/or display <NUM>. In various embodiments, the remote unit <NUM> may include one or more of the processor <NUM>, the memory <NUM>, the transmitter <NUM>, and the receiver <NUM>, and may not include the input device <NUM> and/or the display <NUM>.

In certain embodiments, the processor <NUM> may generate a sequence. In some embodiments, the processor <NUM> may select a resource from a resource pool.

In some embodiments, the memory <NUM> stores data relating to an indication to be provided to another device.

The transmitter <NUM> is used to provide UL communication signals to the base unit <NUM> and the receiver <NUM> is used to receive DL communication signals from the base unit <NUM>. In one embodiment, the transmitter <NUM> is used to transmit a sequence on a resource. The transmission of the sequence on the resource indicates a behavior of the remote unit <NUM>. In certain embodiments, the receiver <NUM> may be used to receive data. In one embodiment, the receiver <NUM>, on each resource within a resource pool, detects whether a sequence is transmitted. Transmission of the sequence within the resource pool may indicate a behavior of a device that transmits the transmission of the sequence.

<FIG> depicts one embodiment of an apparatus <NUM> that may be used for configuring device-to-device transmission. The apparatus <NUM> includes one embodiment of the base unit <NUM>. Furthermore, the base unit <NUM> may include a processor <NUM>, a memory <NUM>, an input device <NUM>, a display <NUM>, a transmitter <NUM>, and a receiver <NUM>. As may be appreciated, the processor <NUM>, the memory <NUM>, the input device <NUM>, and the display <NUM> may be substantially similar to the processor <NUM>, the memory <NUM>, the input device <NUM>, and the display <NUM> of the remote unit <NUM>, respectively.

The processor <NUM> is used to generate a first signal indicating a first sequence and a first resource pool. Transmission of the first sequence within the first resource pool indicates a behavior of a first device that transmits the transmission of the first sequence. The first resource pool is configured for use by multiple devices. The transmitter <NUM> is used to transmit the first signal to the first device. Although only one transmitter <NUM> and one receiver <NUM> are illustrated, the base unit <NUM> may have any suitable number of transmitters <NUM> and receivers <NUM>.

<FIG> illustrates one embodiment of communications <NUM> for configuring device-to-device transmission. Specifically, communications <NUM> between an eNB <NUM>, a V-UE <NUM>, and a P-UE <NUM> are illustrated. A first communication <NUM> and a second communication <NUM> are sent from the eNB <NUM> and are used to configure the V-UE <NUM> and the P-UE <NUM>; however, in certain embodiments, the V-UE <NUM> and/or the P-UE <NUM> may be pre-configured, configured via a specification, and so forth. In some embodiments, the first communication <NUM> and/or the second communication <NUM> may be used to configure multiple V-UEs and/or multiple P-UEs to use a common sequence and/or to use a common resource for communicating the common sequence.

The first communication <NUM> and/or the second communication <NUM> may include information regarding a time-frequency resource for transmission of the third communication <NUM>. Specifically, in certain embodiments, the information may indicate that the third communication <NUM> is to be transmitted in a gap of a subframe within a resource pool used for transmission (e.g., the last symbol of the subframe). This gap may be defined in each D2D subframe for the purpose of avoiding the possible collision between D2D signal transmissions and following cellular transmissions, such as when D2D transmissions and cellular transmissions are sharing the same carrier and using different transmission timing. However, for V2V and V2X transmission, a dedicated carrier frequency for intelligent traffic systems ("ITS") may be used so that the gap may not be necessary. In embodiments in which V2X and/or D2D transmissions share the same carrier frequency with cellular transmissions, the gap in one subframe for V2V/V2X usage may not be necessary when this subframe is followed by another subframe also for V2V/V2X usage. This case may occur in embodiments in which the resource pool design in the time domain for V2V/V2X is consecutive in order to decrease the time to switch between V2V/V2X transmission/receiving and cellular transmission.

The first communication <NUM> may include information regarding a V2V resource pool and/or the second communication <NUM> may include information regarding the P-UE <NUM> transmission resource pool. In certain embodiments, the first communication <NUM> may also include information regarding the P-UE <NUM> transmission resource pool. In some embodiments, the first and second communications <NUM> may be one communication that is sent to the V-UE <NUM> and the P-UE <NUM> that includes the V2V resource pool and the P-UE <NUM> transmission resource pool.

In certain embodiments, the P-UE <NUM> transmission resource pool (e.g., time-frequency resource) may be combined and/or shared with the V2V resource pool because the purpose of a P-UE <NUM> transmission is to let the V-UE <NUM> detect the existence of the P-UE <NUM>. In some embodiments, when the V2V resource pool is configured by the eNB <NUM> or preconfigured, the P-UE <NUM> transmission resource pool may be similarly configured or preconfigured. In various embodiments, a bitmap (or other mapping) may be used to indicate whether the gap of one subframe within the V2V resource pool is used for the P-UE <NUM> transmission. In certain embodiments, a periodicity and/or initial subframe offset within the V2V resource pool may be configured by the eNB <NUM> or preconfigured.

The first communication <NUM> and/or the second communication <NUM> may include information regarding a signal to be transmitted from the P-UE <NUM> to the V-UE <NUM>. The signal may indicate a sequence. In certain embodiments, the sequence may be a constant amplitude zero autocorrelation ("CAZAC") sequence to facilitate maintaining low peak to average power ratio ("PAPR") requirement in P-UE <NUM> implementation. In such embodiments, the concrete length of the CAZAC sequence may be configured by RRC signaling, preconfigured, or fixed in a specification. Moreover, each complex value in the sequence may be mapped to one RE. In some embodiments, the generation of a CAZAC sequence may be performed by introducing a new root index. In various embodiments, an existing demodulation reference signal ("DMRS") sequence may be used and may be selected by setting fixed values for a Cell-ID, a cyclic shift, and an OCC.

The third communication <NUM> is sent from the P-UE <NUM> to the V-UE <NUM> to provide an indication to the V-UE <NUM>. In various embodiments, the third communication <NUM> is sent to indicate a behavior of the P-UE <NUM>. For example, in some embodiments, the third communication <NUM> is sent to indicate that the P-UE <NUM> is crossing a road and/or in an intersection. As may be appreciated, the behavior may be any suitable behavior of the P-UE <NUM>. By limiting communication from the P-UE <NUM> to the V-UE <NUM> to indicating the behavior (e.g., to only indicate the behavior to the V-UE <NUM>), battery power of the P-UE <NUM> may be conserved.

For example, when the P-UE <NUM> is crossing a road, the P-UE <NUM> may transmit a signal indicating a specified sequence that may have been preconfigured, configured by the first and/or second communications <NUM> and/or <NUM>, or defined by a specification. The P-UE <NUM> may transmit the signal using a resource pool for P-UE <NUM> transmission as described above. In one embodiment, the resource pool and/or the signal indicating the specified sequence are common to multiple P-UEs <NUM>. Accordingly, multiple P-UEs <NUM> may be enabled to transmit the same signal in the same resource to result in a combined signal having a combined gain. By using the same resource pool, resource collision may be avoided. Furthermore, the P-UEs <NUM> may reduce power consumption and/or improve performance gain by limiting transmissions, such as by limiting transmissions form the P-UEs <NUM> to the V-UEs <NUM> to instances in which the P-UEs <NUM> are crossing the road and/or in an intersection.

In some embodiments, the V-UE <NUM> may receive the third communication <NUM>, detect a gap (e.g., the last symbol within the P-UE <NUM> transmission resource pool), and match a received signal of the third communication <NUM> with a sequence (known by the V-UE <NUM> through configuration, pre-configuration, or defined in a specification) to determine whether there is a P-UE <NUM> crossing a road.

<FIG> illustrates one embodiment of an implementation <NUM> of device-to-device transmission. As illustrated, a road <NUM> may include a first V-UE <NUM>, a second V-UE <NUM>, and a third V-UE <NUM> traveling thereon. Moreover, a P-UE <NUM> may cross the road <NUM>. At the time of the P-UE <NUM> crossing the road <NUM> and/or just before the P-UE <NUM> crosses the road <NUM>, the P-UE <NUM> may send a communication to the first, second, and third V-UEs <NUM>, <NUM>, and <NUM>. The communication may be substantially similar to the third communication <NUM> described above to indicate to the first, second, and third V-UEs <NUM>, <NUM>, and <NUM> that the P-UE <NUM> is about to cross the road <NUM> and/or is crossing the road <NUM>.

<FIG> is a schematic flow chart diagram illustrating one embodiment of a method <NUM> for configuring device-to-device transmission. In some embodiments, the method <NUM> is performed by an apparatus, such as the base unit <NUM>. In certain embodiments, the method <NUM> 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 <NUM> may include generating <NUM> a first signal indicating a first sequence and a first resource pool. In such an embodiment, transmission of the first sequence within the first resource pool indicates a behavior of a first device that transmits the transmission of the first sequence, and the first resource pool is configured for use by multiple devices. The method <NUM> may also include transmitting <NUM> the first signal to the first device, and the method <NUM> may end.

In one embodiment, the method <NUM> includes generating a second signal for indicating the first sequence and the first resource pool, and transmitting the second signal to a second device. In a further embodiment, the method <NUM> includes generating a third signal for indicating a second sequence and the first resource pool. In such an embodiment, transmission of the second sequence within the first resource pool indicates a behavior of a third device that transmits the transmission of the second sequence. Moreover, the method <NUM> may include generating a fourth signal for indicating the first sequence, the second sequence, and the first resource pool. Furthermore, the method <NUM> may include transmitting the third signal to the third device, and transmitting the fourth signal to the second device. In some embodiments, the first sequence and the second sequence are the same. In certain embodiments, one sequence in each subframe within the first resource pool is transmitted. In some embodiments, more than one sequence in each subframe within the first resource pool is transmitted.

In various embodiments, each resource within the first resource pool includes a gap in a subframe. In certain embodiments, each resource within the first resource pool includes a last symbol in a subframe. In one embodiment, the first resource pool is located in the last symbol in a subframe configured for the second device. In some embodiments, the first sequence is a reference signal. In various embodiments, the behavior includes the first device crossing a road.

<FIG> is a schematic flow chart diagram illustrating one embodiment of a method <NUM> for transmitting a device-to-device transmission. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM> (e.g., P-UE). In certain embodiments, the method <NUM> 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 <NUM> may include generating <NUM> a sequence. The method <NUM> may also include selecting <NUM> a resource from a resource pool. The method <NUM> may include transmitting <NUM> the sequence on the resource, and the method <NUM> may end. In one embodiment, the transmission of the sequence on the resource indicates a behavior of an apparatus.

In one embodiment, the method <NUM> includes receiving a signal for indicating the sequence and the resource pool. In a further embodiment, the method <NUM> includes selecting the resource randomly from the resource pool. In some embodiments, the sequence is preconfigured. In certain embodiments, the resource pool is preconfigured. In some embodiments, the behavior includes the apparatus crossing a road.

<FIG> is a schematic flow chart diagram illustrating one embodiment of a method <NUM> for receiving a device-to-device transmission. In some embodiments, the method <NUM> is performed by an apparatus, such as the remote unit <NUM> (e.g., V-UE). In certain embodiments, the method <NUM> 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 <NUM> may include, on each resource within a resource pool, detecting <NUM> whether a sequence is transmitted, and the method <NUM> may end. In such embodiments, transmission of the sequence within the resource pool indicates a behavior of a device that transmits the transmission of the sequence.

In some embodiments, the method <NUM> includes receiving a signal indicating the sequence and the resource pool. In certain embodiments, the method <NUM> includes generating a warning message if the sequence is transmitted. In such embodiments, the warning message may indicate that a pedestrian is crossing a road. In various embodiments, the sequence is preconfigured. In one embodiment, the resource pool is preconfigured. In some embodiments, the behavior includes the device crossing a road.

Claim 1:
A remote unit (<NUM>) comprising:
a receiver (<NUM>) arranged to receive a signal indicating a first sequence and a first resource pool, wherein transmission of the first sequence within the first resource pool indicates that the remote unit (<NUM>) is crossing a road, wherein the first resource pool is configured for use by multiple devices;
a processor (<NUM>) arranged to generate a first signal indicating the first sequence; and
a transmitter (<NUM>) that wirelessly transmits the first signal when the remote unit (<NUM>) is crossing a road.