WO2020089870A1

WO2020089870A1 - Transmitting reference signals for device-to-device communications

Info

Publication number: WO2020089870A1
Application number: PCT/IB2019/059417
Authority: WO
Inventors: Hieu DO; Wanlu Sun; Ricardo BLASCO SERRANO
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2018-11-02
Filing date: 2019-11-01
Publication date: 2020-05-07

Abstract

The present disclosure describes wireless communication devices and methods performed by such wireless devices for providing reference signals for device-to-device communication. An exemplary method includes determining, for a first transmission, an allocation of physical resources according to a subframe format that positions one or more reference signals for channel state information at the transmitter (CSIT) in a symbol position that avoids overlap with a data symbol in a concurrent second transmission and transmitting the first transmission having the allocation of physical resources accord to the determined subframe format.

Description

TRANSMITTING REFERENCE SIGNALS FOR DEVICE-TO-DEVICE

COMMUNICATIONS

RELATED APPLICATIONS

[0001] This application claim priority to and the benefit of U.S. Provisional Application No. 62/755,216, filed on November 2, 2018 and entitled “TRANSMITTING REFERENCE SIGNALS FOR DEVICE-TO-DEVICE COMMUNICATIONS,” the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

[0002] The present disclosure generally relates to the field of wireless network communications, and more particularly, to deploying LTE-M in coexistence with New Radio (NR).

BACKGROUND

[0003] LTE vehicle-to-anything (V2X) was specified by 3GPP in Release 14 and was enhanced in Release 15. LTE V2X consists of basic features and enhancements that allow for vehicular communications. One of the most relevant aspects is the introduction of direct vehicle-to- vehicle (V2V) communication functionalities. The specifications support other type of vehicle-to-anything (V2X) communications, including V2P (vehicle-to-pedestrian or pedestrian-to-vehicle), V2I (vehicle-to-infrastructure), etc., as shown in FIG. 1.

[0004] These direct communication functionalities are built upon LTE D2D (device-to- device), also known as ProSe (Proximity Services), as first specified in the Release 12 of LTE, and include many important enhancements targeting the specific characteristics of vehicular communications. For example, LTE V2X operation is possible with and without network coverage and with varying degrees of interaction between the UEs (user equipment) and the NW (network), including support for standalone, network-less operation.

[0005] LTE V2X mainly targets basic road safety use cases like forward collision warning, emergency braking, roadworks warning, etc. Vehicles UE supporting V2X applications can exchange their own status information such as position, velocity (speed and heading), with other nearby vehicles, infrastructure nodes, and/or pedestrians. The typical messages sent by the vehicles are Co-operative Awareness Message (CAM) and Decentralized Environmental Notification Message (DENM), defined by the European Telecommunications Standards Institute (ETSI), or Basic Safety Message (BSM), defined by the Society of the Automotive Engineers (SAE).

[0006] A new radio (NR) version of V2X communications is under development. The NR V2X is to mainly target more advanced V2X services, which can be categorized into four use case groups: vehicles platooning, extended sensors, advanced driving, and remote driving. The advanced V2X services would require enhanced NR systems and a new NR sidelink to meet stringent requirements in terms of latency and reliability. The NR V2X system is also intended to have higher system capacity and better coverage and to allow for easy extension to support the future development of further advanced V2X services and other services.

SUMMARY

[0007] The following groups of enumerated clauses provide a summary of some aspects of the present disclosure.

[0008] Group A Embodiments

[0009] 1. A method performed by a wireless device for providing reference signals for device-to-device communication, the method comprising: determining, for a first transmission, an allocation of physical resources according to a subframe format that positions one or more reference signals for channel state information at the transmitter (CSIT) in a symbol position that avoids overlap with a data symbol in a concurrent second transmission; and transmitting the first transmission having the allocation of physical resources accord to the determined subframe format.

[0010] 2. The method of embodiment 1, wherein the one or more reference signals comprises an SL-CSI-RS symbol and wherein determining the allocation of physical resources according to the subframe format comprises: muting a DMRS symbol and including the SL-CSI-RS symbol in the position of the muted DMRS symbol; multiplexing the SL-CSI-RS symbol with the DMRS symbol to generate a multiplexed symbol and transmitting the multiplexed symbol in the position originally used for the DMRS; or transmitting the SL-CSI-RS in the guard period of the slot.

[0011] 3. The method of embodiment 2, wherein multiplexing the SL-CSI-RS symbol with the DMRS symbol comprises utilizing orthogonal sequences for the DMRS symbol and the SL-CSI-RS symbol. [0012] 4. The method of embodiment three, wherein utilizing orthogonal sequences comprises using shifted versions of a base sequence.

[0013] 5. The method of any of the previous embodiments, wherein muting the DRMS symbol and including the SL-CSI-RS symbol in the position of the muted DMRS symbol comprises: identifying a plurality of DMRS symbols included in the subframe format, the plurality of DMRS symbols including at least a first DMRS symbol, a last DMRS symbol, and an intermediate DMRS symbol positioned between the first DMRS symbol and the last DMRS symbol; muting the intermediate DMRS symbol; and including the SL-CSI-RS symbol in the position of the muted intermediate DMRS symbol.

[0014] 6. The method of any of the previous embodiments, wherein the subframe format comprises: a first symbol for AGC settling; 2nd and 3rd symbols for PSCCH; 7th, lOth, 13th symbols for DMRS; 5th, 6th, 8th, 9th, 1 lth, l2th symbols for data of the PSSCH; a l4th symbol is for GP, and wherein a 4th symbol of carries SL-CSI-RS.

[0015] 7. The method of any of the previous embodiments, wherein the muting the DMRS symbol comprises muting a first DMRS symbol of a plurality of DMRS symbols.

[0016] 8. The method of any of the previous embodiments, where in the method further comprises: determining a speed of the wireless device; comparing the speed of the wireless device to a threshold speed; muting the DMRS symbol when the speed of the wireless device is less than the threshold speed; and multiplexing the SL-CSI-RS with the DMRS symbol or transmitting the SL-CSI-RS in the guard period when speed of the wireless device is greater than or equal to the threshold speed.

[0017] 9. The method of any of the previous embodiments, further comprising notifying a receiving wireless device of the position of the muted DMR symbol.

[0018] 10. The method of any of the previous embodiments, wherein multiplexing the

SL-CSI-RS symbol with the DMRS symbol to generate a multiplexed symbol comprises utilizing a mapping with data or without data.

[0019] 11. The method of any of the previous embodiments, wherein the one or more reference signals comprises splitting a reference signal sequence p = [p_1; p₂, p₃, , p_N] into a first subsequence, a second subsequence, and a third subsequence by: generating the first subsequence: p_dmrs ⁼ [pi, p₃, Ps, , P_/v-il for DMRS, to be transmitted at both a first antenna and a second antenna; generating the second subsequence: PCSIRSI ⁼ \p_2> Ve_>— _> P_/v— 2] f°^r the SL-CSI-RS1 to be transmitted from the first antenna generating the third subsequence: Pcs s ⁼ [p₄, Pa.—_> P_N] f°^r the SL-CSI-RS2 to be transmitted from the second antenna. ; and wherein the method further comprises transmitting the first subsequence, the second subsequence, and the third subsequence.

[0020] 12. The method of any of the previous embodiments, wherein transmitting the

SL-CSI-RS in the guard period comprises transmitting the SL-CSI-RS the first half of the guard period symbol and not in the second half of the guard period.

[0021] 13. The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to the base station.

[0022] Group B Embodiments

[0023] 14. A method performed by a base station for providing reference signals for device-to-device communication, the method comprising: transmitting an indication to a UE that instructs that UE to: mute a DMRS symbol and including an SL-CSI-RS symbol in the position of the muted DMRS symbol; multiplex the SL-CSI-RS symbol with the DMRS symbol to generate a multiplex symbol and transmitting the multiplex symbol in the position originally used for the DMRS; or transmit the SL-CSI-RS in the guard period of the slot; when the UE includes the SL-CSI-RS in a transmission.

[0024] 15. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a wireless device.

[0025] Group C Embodiments

[0026] 16. A wireless device for providing reference signals for device-to-device communication, the wireless device comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the wireless device.

[0027] 17. A base station for providing reference signals for device-to-device communication, the base station comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; power supply circuitry configured to supply power to the wireless device.

[0028] 18. A user equipment (UE) for providing reference signals for device-to-device communication, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry, the processing circuitry being configured to perform any of the steps of any of the Group A embodiments, such as: muting a DMRS symbol and including the SL-CSI-RS symbol in the position of the muted DMRS symbol; multiplexing the SL-CSI-RS symbol with the DMRS symbol to generate a multiplex symbol and transmitting the multiplex symbol in the position originally used for the DMRS; or transmitting the SL-CSI-RS in the guard period of the slot, when including an SL-CSI-RS symbol in a transmission to another UE; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

[0029] 19. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments.

[0030] 20. The communication system of the previous embodiment further including the base station.

[0031] 21. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

[0032] 22. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application.

[0033] 23. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group B embodiments.

[0034] 24. The method of the previous embodiment, further comprising, at the base station, transmitting the user data.

[0035] 25. The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application. [0036] 26. A user equipment (UE) configured to communicate with a base station, the

UE comprising a radio interface and processing circuitry configured to performs the of the previous 3 embodiments.

[0037] 27. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a radio interface and processing circuitry, the UE’s components configured to perform any of the steps of any of the Group A embodiments.

[0038] 28. The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.

[0039] 29. The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE’s processing circuitry is configured to execute a client application associated with the host application.

[0040] 30. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the Group A embodiments.

[0041] 31. The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station.

[0042] 32. A communication system including a host computer comprising: communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the UE comprises a radio interface and processing circuitry, the UE’s processing circuitry configured to perform any of the steps of any of the Group A embodiments.

[0043] 33. The communication system of the previous embodiment, further including the UE.

[0044] 34. The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station. [0045] 35. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

[0046] 36. The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

[0047] 37. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

[0048] 38. The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station.

[0049] 39. The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application.

[0050] 40. The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application, wherein the user data to be transmitted is provided by the client application in response to the input data.

[0051] 41. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’ s processing circuitry configured to perform any of the steps of any of the Group B embodiments.

[0052] 42. The communication system of the previous embodiment further including the base station.

[0053] 43. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station. [0054] 44. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

[0055] 45. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

[0056] 46. The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE.

[0057] 47. The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer.

[0058] Combinations of these enumerated embodiments are included within the scope of the present disclosure as well. These embodiments will be better understood by reference to the accompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 depicts an exemplary environment for V2X communication in accordance with some embodiments.

[0060] FIG. 2 depicts a 14-symbol subframe for side communication in accordance with some embodiments.

[0061] FIG. 3 depicts a subframe including two physical sidelink channels in accordance with some embodiments.

[0062] FIG. 4 depicts two transmissions that happen in the same set of radio resources, such that they are overlapping in time and frequency in accordance with some embodiments.

[0063] FIG. 5 depicts two transmissions as in FIG. 4 but with Transmission 1 including a SL- CSI-RS in its 4th symbol rather than DMRS in accordance with some embodiments.

[0064] FIG. 6 depicts a comb-like mapping of DMRS and SF-CSI-RS with data (left) and without data (right) in accordance with some embodiments.

[0065] FIG. 7 depicts a communication system with two antenna elements in accordance with some embodiments. [0066] FIG. 8 is a flowchart of a method according to some embodiments of the present disclosure.

[0067] FIG. 9 depicts a wireless network in accordance with some embodiments.

[0068] FIG. 10 depicts a user equipment in accordance with some embodiments.

[0069] FIG. 11 depicts a virtualization environment in accordance with some embodiments.

[0070] FIG. 12 depicts a network connected via an intermediate network to a host computer in accordance with some embodiments.

[0071] FIG. 13 depicts a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments.

[0072] FIG. 14, 15, 16, and 17 depict flowcharts of methods implemented in a communication system equipment in accordance with some embodiments.

[0073] These figures will be better understood by reference to the following detailed description.

DETAILED DESCRIPTION

[0074] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.

[0075] In wireless communications there is always a need for the two ends of a communication channel (the transmitter and the receiver) to learn the propagation channel between them in order to achieve the desired communication performance. From the transmitter perspective, knowing the channel before sending a signal helps the transmitter adapt its transmission techniques (i.e., to pre-process or pre-code the signal) to best suit the channel condition. From the receiver perspective, knowing the channel that the transmitted signal has experienced allows for effective recovery of the transmitted signal from the received signal. [0076] To facilitate the learning about the propagation channel, pilot signals or reference signals (RS) are commonly used in wireless communications. Usually these reference signals are signals known beforehand by both the transmitter and the receiver and that have some special properties for the receiver to recognize.

[0077] In 3GPP cellular technologies there are several reference signals used for learning the channel at the receiver side (also known as channel state information at the receiver (CSIR) acquisition), most notably the Cell Refence Signal (CRS) and the Demodulation Reference Signal (DMRS). These signals are inserted in certain predefined resource elements of a transmission from the transmitter to the receiver. The receiver detects the RS and uses it to estimate the channel at signal-bearing resource elements of the same transmission, enabling the recovery of the desired signal.

[0078] For learning the channel at the transmitter side (often referred to as channel state information at the transmitter (CSIT) acquisition), the Channel State Information Reference Signal (CSI-RS) or the Sounding Reference Signal (SRS) can be used. The CSI-RS is transmitted by the transmitter for measuring the quality of the channel. The receiver performs the measurement based on the received CSI-RS and then feeds back some measurements or processed measurements as channel quality indicators to the transmitter. The transmitter can use such indicators in pre-processing or precoding the desired signal before the transmission to achieve the best performance, for example in terms of data rate.

[0079] At a receiver, an important step in the demodulation process is to detect which RS has been sent in order to estimate the channel experienced by the RS, then potentially use that channel estimate to estimate the channel experienced by the desired signal. For multi-user communication scenarios like direct D2D or V2X, it is also important to be able to distinguish different reference signals from each other, because each RS is associated with a particular transmission from a particular transmitter. Such a purpose may be typically achieved by relying on the orthogonality or near orthogonality of reference signals. Specifically, different users will be assigned different RS sequences that have high auto-correlation and low cross-correlation. The receiver will match its local copies of the RS sequences to the received RS to find out which sequence was used by the transmitter.

[0080] As mentioned above, LTE V2X communications (Rel-l4 and Rel-l5) may be designed so as to mainly target basic road safety services, for which broadcast transmissions are most suitable. As a result, no feedback from the receiver to the transmitter is expected and therefore only DMRS is necessary and feasible. To combat the sometimes severe impact of the Doppler effect in the V2V channels as two communication vehicles move away from or towards each other, LTE V2X embeds four DMRS symbols in a l4-symbol subframe for LTE sidelink V2X, as illustrated in FIG. 2. As shown in FIG. 2, the first symbol is used for settling the automatic gain control (AGC) at the receiver and the last symbol is used as a guard period (GP).

[0081] For the advanced services that the NR V2X is aiming to support, unicast and groupcast transmissions may be beneficial. This is partly because there are fewer entities involved in a unicast or a groupcast session than in broadcast, making it easier to apply advanced transmission and reception techniques, thereby achieving higher quality of services. Therefore, support of unicast and multicast was named one of the goals of the current study item (SI) by RAN1 [3GPP RP- 181480]. Since advanced transmission techniques often entail channel state information at the transmitter, reference signals for CSIT acquisition is necessary for NR V2X. For that purpose, a version of CSI-RS / SRS adapted for the sidelink may be deemed most feasible. In the remaining part of this disclosure this is referred to as“SF-CSI-RS.” It should be noted that for the purpose of channel estimation and demodulation at the receiver, equivalently CSIR acquisition, the DMRS may be used for NR V2X.

[0082] A complete transmission of a message in the sidelink typically requires a transmission of two types of information: the control information that tells the receiver in which resources the actual data will be transmitted, and the data itself. This requires two types of physical channels in the sidelink: the Physical Sidelink Control Channel (PSCCH, for control information) and the Physical Sidelink Shared Channel (PSSCH, for the data). A viable structure of the PSCCH and the PSSCH is depicted in FIG. 3.

[0083] As with the subframe structure of the FTE V2X, the last symbol of an NR SF V2X slot is used as a guard period (GP), such that no data is transmitted in this symbol. The guard period serves as a turn-around time for transmit-to-receive switching and as a means to avoid interference to a transmission in the cellular interface in the next slot (that might happen due to lower-accuracy timing synchronization of the sidelink.) Within the above frame structure, the PSCCH and PSSCH have their own DMRS. The SF-CSI-RS, when present, may be transmitted within the PSSCH.

[0084] There currently exist certain challenge(s). As described herein, there are at least two types of reference signals for NR sidelink V2X: the DMRS for CSIR acquisition and the SF- CSI-RS for CSIT acquisition. While the SF-CSI-RS may be needed only when a transmitter wants to perform some advanced transmission techniques such as beamforming or spatial multiplexing, the DMRS is always needed since it is crucial for the demodulation of received signals. Moreover, due to the fast-changing propagation condition of the direct V2V channel, it is expected that a high density of the DMRS in the time domain is needed to track the channel, at least as dense as that of LTE V2X in FIG. 2. The above characteristics of the reference signals for SL NR V2X, plus the uncoordinated nature of device-to-device transmissions in the sidelink, lead to the following two problems.

[0085] First, while all relevant transmissions may have the DMRS, only some transmissions have SF-CSI-RS. If a receiver receives two transmissions from two transmitters in the same resources, one with DMRS only and one with DMRS and SF-CSI-RS, it will have difficulty making use of the SF-CSI-RS. The reason is that a reference signal is often detected at the receiver by relying on the orthogonality with other reference signals, as described above. This is to be guaranteed for DMRS, since the DMRS is present in both transmissions and usually occupies the same resource elements. In other words, a DMRS usually overlaps with another DMRS from the other transmission and they are separable thanks to the orthogonality. However, this is not the case with the SF-CSI-RS in the scenario under discussion because the SF-CSI-RS is only present in one transmission, hence it overlaps with a data symbol in the other transmission. Since the data and the RS cannot be guaranteed to be orthogonal, it is difficult for the receiver to detect and make use of the SF-CSI-RS. FIG. 4 illustrates the scenario, with the slot format similar to that of FIG. 3. FIG. 4 shows an example of two transmissions that happen in the same set of radio resources, such that they are overlapping in time and frequency. For both transmissions: the first symbol is for AGC settling; the 2nd and 3rd symbols are for PSCCH; the 4th, 7th, lOth, l3th symbols are for DMRS (can be mixed with data); the 6th, 8th, 9th, l lth, l2th symbols carry data of the PSSCH; the l4th symbol is for GP. The 5th symbol of Transmission 1 carries an SF-CSI-RS while the 5th symbol of Transmission 2 carries data.

[0086] Second, since the DMRS overhead is already high (for example, up to 4 symbols of the PSSCH contain DMRS), having also SF-CSI-RS in the transmission induces a high overhead, negatively impacting the data rate. These two problems are addressed herein in order to maximize the benefits of the RS in NR V2X.

[0087] Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. The disclosure describes the following solutions to the problem: muting or dropping part of the DMRS when the SF-CSI-RS needs to be sent and put the SL-CSI-RS in place of the muted/dropped DMRS, multiplexing DMRS and SL-CSI-RS in the same symbol, and transmitting SL-CSI-RS in the guard period of the slot.

[0088] There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.

[0089] Certain embodiments may provide one or more of the following technical advantage(s). The proposed solutions enable CSI acquisition at both the transmitter and the receiver while minimizing the overhead caused by the necessary reference signals.

Additional Explanation

[0090] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0091] The solutions in this section are presented in the context of the DMRS and the SL- CSI-RS of the sidelink or direct V2X communications, but can be applicable to other types of reference signals and in any type of communication wherein different transmissions can partly or fully overlap in terms of radio resources. Examples in this section are often pictorially illustrated using the transmission format in FIG. 3, but the disclosed solutions apply equally to other transmission formats, e.g., the one given in FIG. 2.

[0092] As illustrated in FIG. 4, in can happen that the SL-CSI-RS of a transmission overlaps with the data symbol of another transmission, making it hard for the receiver to detect and make use of the SL-CSI-RS. To solve the problem, this disclosure describes three main solutions to the problem: Solution 1 - the transmitter of the SL-SCI-RS mutes one of the DMRS in the same transmission and transmit the SL-CSI-RS instead; Solution 2 - instead of transmitting the SL-CSI-RS in place of a DMRS as in Solution 1 , the transmitter multiplexes the SL-CSI-RS with a DMRS and transmits them in the symbol originally used for the DMRS (e.g., using orthogonal sequences); Solution 3 - the SL-CSI-RS is transmitted in the guard period of the slot.

[0093] The technical advantage of the above solutions is that by means of the solutions the original problem of overlapping data is transformed into the problem of overlapping between DMRS and SL-CSI-RS (solution 1 and 2) or to no interference at all for the SL-CSI-RS (solution 3). And according to the present disclosure, the problem of overlapping between DMRS and SL-CSI-RS can be effectively mitigated by proper design of the reference signals, in contrast to the original problem where the properties of the data symbol that overlaps with the SL-CSI-RS cannot be controlled. At the same time, the above solutions also solve the second problem listed herein, namely the high overhead due to transmitting DMRS and SL- CSI-RS in separate symbols.

[0094] In the following embodiments we use the term“DMRS symbol” to denote an OFDM symbol that contains the DMRS. In this symbol, the DMRS can occupy either all the resource elements or some of the resource elements (for example when the DMRS is frequency multiplexed with data symbols). The same terminology applies for SL-CSI-RS symbol.

Some Embodiments for Solution 1

[0095] In this embodiment, the UE transmitting SL-CSI-RS drops one of its DMRS symbols in the same slot and transmits the SL-CSI-RS symbols in place of the dropped DMRS symbols. The SL-CSI-RS is multiplexed with data within the SL-CSI-RS symbol in the same way the dropped DMRS would have been multiplexed with data. An example is given in FIG. 5, which illustrates the same situation as in FIG. 4 but now Transmission 1 has SL-CSI-RS in its 4th symbol instead of DMRS. As a result, the 5th symbol of Transmission 1 can be used for carrying data of the PSSCH. An illustrative example of FIG. 5 shows two transmissions happening in the same set of radio resources (overlap in time and frequency). For both transmissions: the first symbol is for AGC settling; the 2nd and 3rd symbols are for PSCCH; the 7th, lOth, l3th symbols are for DMRS (can be multiplexed with data); the 5th, 6th, 8th, 9th, l lth, l2th symbols carry data of the PSSCH; the l4th symbol is for GP. The 4th symbol of Transmission 1 carries SL-CSI-RS while the 4th symbol of Transmission 2 carries DMRS.

[0096] In some embodiments, the UE prioritizes dropping the first DMRS symbols among the plurality of its DMRS symbols. In so doing, the receiver of the SL-CSI-RS can process the SL-CSI-RS and produce CSI feedback quickly, e.g., at the end of the same slot or in the next slot. An example is given in FIG. 5: the 4th symbol of Transmission 1, which could have been used to carry the first DMRS in the same way as in FIG. 4, is now used for SL-CSI-RS.

[0097] In some embodiments, the UE prioritizes dropping a DMRS symbol which is neither the first nor the last in the plurality of DMRS symbols (i.e. an intermediate DMRS symbol having at least one other DMRS symbol ahead and at least one other DMRS symbol behind in the transmission). In the context of FIG. 4, this means that Transmission 1 drops the DMRS in either the 7th or the 10th symbol and transmits SL-CSI-RS instead. In so doing, the impacts of dropping DMRS on the channel estimates of the data-carrying symbols are minimized. Specifically, if the DMRS in the 4th symbol of Transmission 1 is dropped the channel estimates of the 5th and the 6th symbols could potentially suffer more than when the DMRS in the 7th or the lOth symbol is dropped. This is because in the former case the receiver UE may need to perform extrapolation (based on the channel estimates of the remaining DMRS symbols) to obtain the channel estimates at the 5th and the 6th symbol, while in the latter case an interpolation would be used which typically gives more accurate results.

[0098] In some embodiments, the dropping of DMRS may only be allowed when a certain condition or conditions is/are met. For example, dropping of DMRS may be allowed only when the UE speed is lower than a certain threshold. This may be enforced to maintain good channel estimation quality when the channel changes fast. The threshold can be configured by the network or may be preconfigured in the device. Furthermore, the condition or the rule to allow dropping DMRS can be preconfigured.

[0099] In some embodiments, the sequences for SL-CSI-RS and the sequences for DMRS are chosen such that they are as much orthogonal as possible or have maximized orthogonality. This is to help the receiver UE in separating a DMRS and a SL-CSI-RS when they overlapped. In one example, the sequences are different shifted versions of the same base Zadoff-Chu (ZC) sequence or its extension.

[00100] In some embodiments, the presence of SL-CSI-RS (and correspondingly, the absence of DMRS) is signalled using control signalling (e.g., a field in the PSCCH carried in the slot, NW configuration, resource pool or bandwidth part configuration, etc.).

[00101] One UE implementation embodiment consists of performing channel estimation using all the DMRS symbols except the muted one. For example, if DMRS is usually transmitted in symbols 4, 7, 10, and 13 but the transmitter mutes the DMRS transmission in symbols 4, then the receiver estimates the channel using only symbols 7, 10, and 13. Whether to use the usual channel estimation approach (based on all DMRS symbols) or the alternative one (based on the reduced set of DMRS symbols) may be decided after decoding some control information (e.g., a field in the PSCCH carried in the slot, NW configuration, resource pool or bandwidth part configuration, etc.).

[00102] Another UE implementation embodiment consists of performing channel estimation using all the available DMRS symbols and the SL-CSI-RS symbol. Whether to use the usual channel estimation approach (based only on DMRS symbols) or the alternative one (based on DMRS symbols and SL-CSI-RS) may be decided after decoding some control information (e.g., a field in the PSCCH carried in the slot, NW configuration, resource pool or bandwidth part configuration, etc.).

Some Embodiments for Solution 2

[00103] In this solution, the UE transmitting SL-CSI-RS multiplexes the SL-CSI-RS with one of its DMRS and transmits the multiplexed signal in the corresponding DMRS symbol.

[00104] In some embodiments, the UE may drop some resource elements carrying DMRS in the DMRS symbol and transmits resource elements carrying SL-CSI-RS in place of the dropped DMRS resource elements. For example, the DMRS resource elements and the SL- CSI-RS resource elements can be multiplexed in a comb manner, i.e., the DMRS and the SL- CSI-RS are alternately mapped to the subcarriers of the same symbol. This does not preclude further multiplexing with data in the same symbol, which may be done in some other embodiments. Examples are given in FIG. 6, which shows a comb-like mapping of DMRS and SL-CSI-RS, with data (left) and without data (right).

[00105] In some other embodiments, the samples of a reference signal sequence are split into different parts, where some parts act as DMRS while the other parts act as SL-CSI-RS. By samples, we mean the modulated symbols carried by resource elements/subcarriers in frequency domain. An example with two antenna elements and one antenna port is illustrated in FIG. 7, which shows an example of transmitting a DMRS symbol according to Solution 2. One RS sequence is split into three subsequences, used for DMRS, SL-CSI-RS 1 and SL-CSI- RS2.

[00106] In this example, a reference signal sequence p = [ri, r₂, R₃, , P_/v] is split into three subsequences as follows:

[00107] The first subsequence: p_dmrs ⁼ [Po P₃, Ps_{> >} P_/v-il i^s used for DMRS, to be transmitted at both Antenna 1 and Antenna 2 and may typically be pre-coded. We denote the precoding vector by c = [c₁, c₂]^T.

[00108] The second subsequence: PCSIRSI ⁼ [p₂, Pe_>— _> P_/v—₂] may be used for the SL-CSI- RS 1 being transmitted from Antenna 1.

[00109] The third subsequence: Pcsms ⁼

_> PN ] ^may be used for the SL-CSI-RS2 being transmitted from Antenna 2.

[00110] The DMRS, SL-CSI-RS1, and SL-CSI-RS2 may be multiplexed in a comb manner in the subcarrier domain of the same OFDM symbol, possibly with zero-padding at some subcarriers, such that only one of the two SL-CSI-RS’s is active in a given subcarrier. In this way, the sequences transmitted from the two antenna elements are the following: [00111] From antenna 1, the sequence p_Txl =

p₂, <Ar₃, 0 , ... , c₁p_N-3, p_{N 2}, ^CIPN-I_> 0] is transmitted.

[00112] From antenna 2, the sequence p_Tx2 = [c₂p_1; 0, c₂p₃, p₄, , c₂p_w-3, 0, c₂p_N®, p_N ] is transmitted.

[00113] In some embodiments, the power split between DMRS and SL-CSI-RS is part of a specification, pre-configuration (e.g., in a SIM card), or configuration (e.g., through broadcast or RRC signaling). For example, the power may be distributed equally between both RS types or in some other arbitrary way.

[00114] In some further embodiments, the receiver used this power split information to perform channel estimation. For example, it may apply an algorithm that is aware of the reduced power level of the DMRS multiplexed with the SL-CSI-RS, so that the receiver is not misled into believing that the channel attenuation is larger. For example, it may amplify the DMRS symbol transmitted with reduced power (alternatively, attenuate the other DMRS symbols).

[00115] In some embodiments, the presence of SL-CSI-RS multiplexed with DMRS is signaled using control signaling (e.g., a field in the PSCCH carried in the slot, NW configuration, resource pool or bandwidth part configuration, etc.).

Some Embodiments for Solution 3

[00116] In this solution, the UE transmitting SL-CSI-RS may transmit the SL-CSI-RS in the guard period symbol of the slot. In some embodiments, the SL-CSI-RS is transmitted using the first half of the guard period symbol and not in the second half of the guard period. In some embodiments, the presence of the SL-CSI-RS in the guard period is signaled using control signaling (e.g., a field in the PSCCH carried in the slot, NW configuration, resource pool or bandwidth part configuration, etc.).

[00117] It should be further noted that, in some embodiments, the transmitter UE may indicate in the control channel PSCCH, or in some other signaling methods such as MAC CE and RRC, the way the SL-CSI-RS is being transmitted in the associated PSSCH. For example, the UE may indicate that it is replacing one of the DMRS symbols by the SL-CSI-RS symbol and indicates the index of the replaced DMRS symbol. In some other embodiments, the method or approach of transmitting SL-CSI-RS is signaled from a network node (e.g., gNB or eNB) to the transmitter and/or receiver(s) via RRC signaling or via downlink control information (DCI).

[00118] FIG. 8 is a flowchart of a method 800 according to some embodiments of the present disclosure. Embodiments of the method 800 may include one or more of the enumerated operations shown in FIG. 8. Additional embodiments of the method 800 may include additional operations and/or alternative operations before, after, in between, or in place of the enumerated operations. As shown in FIG. 8, the method 800 may begin at operation 802 in which a UE determines, for a first transmission, an allocation of physical resources according to a subframe format that positions one or more reference signals for channel state information at the transmitter (CSIT) in a symbol position that avoids overlap with a data symbol in a concurrent second transmission. The concurrent second transmission may be a transmission generated by another UE in the vicinity of the determining UE. When the UE is a transmitting UE, the method 800 includes an operation 804A in which the UE transmits the first transmission having the allocation of physical resources accord to the determined subframe format. When the UE is a receiving UE, the method 800 includes an operation 804B in which the UE receives the first transmission having the allocation of physical resources according to the determined subframe format. After the operation 804B, the UE may then decode the received first transmission based on the determined subframe format.

[00119] Although the subj ect matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in FIG. 9. For simplicity, the wireless network of FIG. 9 only depicts network 906, network nodes 960 and 960b, and WDs 910, 9l0b, and 9l0c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node 960 and wireless device (WD) 910 are depicted with additional detail. The WD 910 may be either the transmitting UE or the receiving UE as described above. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.

[00120] The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

[00121] Network 906 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

[00122] Network node 960 and WD 910 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

[00123] As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

[00124] In FIG. 9, network node 960 includes processing circuitry 970, device readable medium 980, interface 990, auxiliary equipment 984, power source 986, power circuitry 987, and antenna 962. Although network node 960 illustrated in the example wireless network of FIG. 9 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node 960 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 980 may comprise multiple separate hard drives as well as multiple RAM modules).

[00125] Similarly, network node 960 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 960 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 960 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 980 for the different RATs) and some components may be reused (e.g., the same antenna 962 may be shared by the RATs). Network node 960 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 960, such as, for example, GSM, WCDMA, FTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 960.

[00126] Processing circuitry 970 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 970 may include processing information obtained by processing circuitry 970 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

[00127] Processing circuitry 970 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 960 components, such as device readable medium 980, network node 960 functionality. For example, processing circuitry 970 may execute instructions stored in device readable medium 980 or in memory within processing circuitry 970. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 970 may include a system on a chip (SOC).

[00128] In some embodiments, processing circuitry 970 may include one or more of radio frequency (RF) transceiver circuitry 972 and baseband processing circuitry 974. In some embodiments, radio frequency (RF) transceiver circuitry 972 and baseband processing circuitry 974 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 972 and baseband processing circuitry 974 may be on the same chip or set of chips, boards, or units

[00129] In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry 970 executing instructions stored on device readable medium 980 or memory within processing circuitry 970. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 970 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 970 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 970 alone or to other components of network node 960, but are enjoyed by network node 960 as a whole, and/or by end users and the wireless network generally.

[00130] Device readable medium 980 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 970. Device readable medium 980 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 970 and, utilized by network node 960. Device readable medium 980 may be used to store any calculations made by processing circuitry 970 and/or any data received via interface 990. In some embodiments, processing circuitry 970 and device readable medium 980 may be considered to be integrated.

[00131] Interface 990 is used in the wired or wireless communication of signalling and/or data between network node 960, network 906, and/or WDs 910. As illustrated, interface 990 comprises port(s)/terminal(s) 994 to send and receive data, for example to and from network 906 over a wired connection. Interface 990 also includes radio front end circuitry 992 that may be coupled to, or in certain embodiments a part of, antenna 962. Radio front end circuitry 992 comprises filters 998 and amplifiers 996. Radio front end circuitry 992 may be connected to antenna 962 and processing circuitry 970. Radio front end circuitry may be configured to condition signals communicated between antenna 962 and processing circuitry 970. Radio front end circuitry 992 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 992 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 998 and/or amplifiers 996. The radio signal may then be transmitted via antenna 962. Similarly, when receiving data, antenna 962 may collect radio signals which are then converted into digital data by radio front end circuitry 992. The digital data may be passed to processing circuitry 970. In other embodiments, the interface may comprise different components and/or different combinations of components.

[00132] In certain alternative embodiments, network node 960 may not include separate radio front end circuitry 992, instead, processing circuitry 970 may comprise radio front end circuitry and may be connected to antenna 962 without separate radio front end circuitry 992. Similarly, in some embodiments, all or some of RF transceiver circuitry 972 may be considered a part of interface 990. In still other embodiments, interface 990 may include one or more ports or terminals 994, radio front end circuitry 992, and RF transceiver circuitry 972, as part of a radio unit (not shown), and interface 990 may communicate with baseband processing circuitry 974, which is part of a digital unit (not shown).

[00133] Antenna 962 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 962 may be coupled to radio front end circuitry 990 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 962 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna 962 may be separate from network node 960 and may be connectable to network node 960 through an interface or port.

[00134] Antenna 962, interface 990, and/or processing circuitry 970 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 962, interface 990, and/or processing circuitry 970 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

[00135] Power circuitry 987 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 960 with power for performing the functionality described herein. Power circuitry 987 may receive power from power source 986. Power source 986 and/or power circuitry 987 may be configured to provide power to the various components of network node 960 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 986 may either be included in, or external to, power circuitry 987 and/or network node 960. For example, network node 960 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 987. As a further example, power source 986 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 987. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

[00136] Alternative embodiments of network node 960 may include additional components beyond those shown in FIG. 9 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 960 may include user interface equipment to allow input of information into network node 960 and to allow output of information from network node 960. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 960.

[00137] As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE) a vehicle-mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (IoT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine -to- machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB- IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

[00138] As illustrated, wireless device 910 includes antenna 911, interface 914, processing circuitry 920, device readable medium 930, user interface equipment 932, auxiliary equipment 934, power source 936 and power circuitry 937. WD 910 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 910, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 910.

[00139] Antenna 911 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 914. In certain alternative embodiments, antenna 911 may be separate from WD 910 and be connectable to WD 910 through an interface or port. Antenna 911, interface 914, and/or processing circuitry 920 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 911 may be considered an interface. [00140] As illustrated, interface 914 comprises radio front end circuitry 912 and antenna 911. Radio front end circuitry 912 comprise one or more filters 918 and amplifiers 916. Radio front end circuitry 914 is connected to antenna 911 and processing circuitry 920, and is configured to condition signals communicated between antenna 911 and processing circuitry 920. Radio front end circuitry 912 may be coupled to or a part of antenna 911. In some embodiments, WD 910 may not include separate radio front end circuitry 912; rather, processing circuitry 920 may comprise radio front end circuitry and may be connected to antenna 911. Similarly, in some embodiments, some or all of RF transceiver circuitry 922 may be considered a part of interface 914. Radio front end circuitry 912 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 912 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 918 and/or amplifiers 916. The radio signal may then be transmitted via antenna 911. Similarly, when receiving data, antenna 911 may collect radio signals which are then converted into digital data by radio front end circuitry 912. The digital data may be passed to processing circuitry 920. In other embodiments, the interface may comprise different components and/or different combinations of components.

[00141] Processing circuitry 920 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD 910 components, such as device readable medium 930, WD 910 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 920 may execute instructions stored in device readable medium 930 or in memory within processing circuitry 920 to provide the functionality disclosed herein.

[00142] As illustrated, processing circuitry 920 includes one or more of RF transceiver circuitry 922, baseband processing circuitry 924, and application processing circuitry 926. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 920 of WD 910 may comprise a SOC. In some embodiments, RF transceiver circuitry 922, baseband processing circuitry 924, and application processing circuitry 926 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 924 and application processing circuitry 926 may be combined into one chip or set of chips, and RF transceiver circuitry 922 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 922 and baseband processing circuitry 924 may be on the same chip or set of chips, and application processing circuitry 926 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 922, baseband processing circuitry 924, and application processing circuitry 926 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 922 may be a part of interface 914. RF transceiver circuitry 922 may condition RF signals for processing circuitry 920.

[00143] In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 920 executing instructions stored on device readable medium 930, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 920 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 920 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 920 alone or to other components of WD 910, but are enjoyed by WD 910 as a whole, and/or by end users and the wireless network generally.

[00144] Processing circuitry 920 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 920, may include processing information obtained by processing circuitry 920 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 910, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

[00145] Device readable medium 930 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 920. Device readable medium 930 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 920. In some embodiments, processing circuitry 920 and device readable medium 930 may be considered to be integrated.

[00146] User interface equipment 932 may provide components that allow for a human user to interact with WD 910. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 932 may be operable to produce output to the user and to allow the user to provide input to WD 910. The type of interaction may vary depending on the type of user interface equipment 932 installed in WD 910. For example, if WD 910 is a smart phone, the interaction may be via a touch screen; if WD 910 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment 932 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 932 is configured to allow input of information into WD 910, and is connected to processing circuitry 920 to allow processing circuitry 920 to process the input information. User interface equipment 932 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 932 is also configured to allow output of information from WD 910, and to allow processing circuitry 920 to output information from WD 910. User interface equipment 932 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 932, WD 910 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

[00147] Auxiliary equipment 934 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment 934 may vary depending on the embodiment and/or scenario.

[00148] Power source 936 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD 910 may further comprise power circuitry 937 for delivering power from power source 936 to the various parts of WD 910 which need power from power source 936 to carry out any functionality described or indicated herein. Power circuitry 937 may in certain embodiments comprise power management circuitry. Power circuitry 937 may additionally or alternatively be operable to receive power from an external power source; in which case WD 910 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 937 may also in certain embodiments be operable to deliver power from an external power source to power source 936. This may be, for example, for the charging of power source 936. Power circuitry 937 may perform any formatting, converting, or other modification to the power from power source 936 to make the power suitable for the respective components of WD 910 to which power is supplied.

[00149] FIG. 10 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE 10200 may be any UE identified by the 3^rd Generation Partnership Project (3GPP), including a NB-IoT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1000, as illustrated in FIG. 10, is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3^rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although FIG. 10 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

[00150] In FIG. 10, UE 1000 includes processing circuitry 1001 that is operatively coupled to input/output interface 1005, radio frequency (RF) interface 1009, network connection interface 1011, memory 1015 including random access memory (RAM) 1017, read-only memory (ROM) 1019, and storage medium 1021 or the like, communication subsystem 1031, power source 1033, and/or any other component, or any combination thereof. Storage medium 1021 includes operating system 1023, application program 1025, and data 1027. In other embodiments, storage medium 1021 may include other similar types of information. Certain UEs may utilize all of the components shown in FIG. 10, or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[00151] In FIG. 10, processing circuitry 1001 may be configured to process computer instructions and data. Processing circuitry 1001 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1001 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

[00152] In the depicted embodiment, input/output interface 1005 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1000 may be configured to use an output device via input/output interface 1005. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE 1000. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE 1000 may be configured to use an input device via input/output interface 1005 to allow a user to capture information into UE 1000. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

[00153] In FIG. 10, RF interface 1009 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1011 may be configured to provide a communication interface to network l043a. Network l043a may encompass wired and/or wireless networks such as a local-area network (FAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network l043a may comprise a Wi-Fi network. Network connection interface 1011 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface 1011 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

[00154] RAM 1017 may be configured to interface via bus 1002 to processing circuitry 1001 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM 1019 may be configured to provide computer instructions or data to processing circuitry 1001. For example, ROM 1019 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium 1021 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1021 may be configured to include operating system 1023, application program 1025 such as a web browser application, a widget or gadget engine or another application, and data file 1027. Storage medium 1021 may store, for use by UE 1000, any of a variety of various operating systems or combinations of operating systems.

[00155] Storage medium 1021 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro- DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium 1021 may allow UE 1000 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium 1021, which may comprise a device readable medium.

[00156] In FIG. 10, processing circuitry 1001 may be configured to communicate with network 1043b using communication subsystem 1031. Network 1043a and network 1043b may be the same network or networks or different network or networks. Communication subsystem 1031 may be configured to include one or more transceivers used to communicate with network 1043b. For example, communication subsystem 1031 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.11, CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1033 and/or receiver 1035 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1033 and receiver 1035 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

[00157] In the illustrated embodiment, the communication functions of communication subsystem 1031 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem 1031 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1043b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1043b may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source 1013 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1000.

[00158] The features, benefits and/or functions described herein may be implemented in one of the components of UE 1000 or partitioned across multiple components of UE 1000. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 1031 may be configured to include any of the components described herein. Further, processing circuitry 1001 may be configured to communicate with any of such components over bus 1002. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1001 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1001 and communication subsystem 1031. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

[00159] FIG. 11 is a schematic block diagram illustrating a virtualization environment 1100 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

[00160] In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 1100 hosted by one or more of hardware nodes 1130. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

[00161] The functions may be implemented by one or more applications 1120 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications 1120 are run in virtualization environment 1100 which provides hardware 1130 comprising processing circuitry 1160 and memory 1190. Memory 1190 contains instructions 1195 executable by processing circuitry 1160 whereby application 1120 is operative to provide one or more of the features, benefits, and/or functions disclosed herein. [00162] Virtualization environment 1100, comprises general-purpose or special-purpose network hardware devices 1130 comprising a set of one or more processors or processing circuitry 1160, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory 1190-1 which may be non-persistent memory for temporarily storing instructions 1195 or software executed by processing circuitry 1160. Each hardware device may comprise one or more network interface controllers (NICs) 1170, also known as network interface cards, which include physical network interface 1180. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1190-2 having stored therein software 1195 and/or instructions executable by processing circuitry 1160. Software 1195 may include any type of software including software for instantiating one or more virtualization layers 1150 (also referred to as hypervisors), software to execute virtual machines 1140 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

[00163] Virtual machines 1140, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1150 or hypervisor. Different embodiments of the instance of virtual appliance 1120 may be implemented on one or more of virtual machines 1140, and the implementations may be made in different ways.

[00164] During operation, processing circuitry 1160 executes software 1195 to instantiate the hypervisor or virtualization layer 1150, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1150 may present a virtual operating platform that appears like networking hardware to virtual machine 1140.

[00165] As shown in FIG. 11, hardware 1130 may be a standalone network node with generic or specific components. Hardware 1130 may comprise antenna 11225 and may implement some functions via virtualization. Alternatively, hardware 1130 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 11100, which, among others, oversees lifecycle management of applications 1120.

[00166] Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[00167] In the context of NFV, virtual machine 1140 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non- virtualized machine. Each of virtual machines 1140, and that part of hardware 1130 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 1140, forms a separate virtual network elements (VNE).

[00168] Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines 1140 on top of hardware networking infrastructure 1130 and corresponds to application 1120 in FIG. 11.

[00169] In some embodiments, one or more radio units 11200 that each include one or more transmitters 11220 and one or more receivers 11210 may be coupled to one or more antennas 11225. Radio units 11200 may communicate directly with hardware nodes 1130 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

[00170] In some embodiments, some signalling can be effected with the use of control system 11230 which may alternatively be used for communication between the hardware nodes 1130 and radio units 11200.

[00171] With reference to FIG. 12, in accordance with an embodiment, a communication system includes telecommunication network 1210, such as a 3GPP-type cellular network, which comprises access network 1211, such as a radio access network, and core network 1214. Access network 1211 comprises a plurality of base stations l2l2a, l2l2b, l2l2c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area l2l3a, 1213b, l2l3c. Each base station l2l2a, l2l2b, l2l2c is connectable to core network 1214 over a wired or wireless connection 1215. A first UE 1291 located in coverage area 1213c is configured to wirelessly connect to, or be paged by, the corresponding base station l2l2c. A second UE 1292 in coverage area 1213a is wirelessly connectable to the corresponding base station l2l2a. While a plurality of UEs 1291, 1292 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1212. [00172] Telecommunication network 1210 is itself connected to host computer 1230, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 1230 may be under the ownership or control of a service provider or may be operated by the service provider or on behalf of the service provider. Connections 1221 and 1222 between telecommunication network 1210 and host computer 1230 may extend directly from core network 1214 to host computer 1230 or may go via an optional intermediate network 1220. Intermediate network 1220 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 1220, if any, may be a backbone network or the Internet; in particular, intermediate network 1220 may comprise two or more sub-networks (not shown).

[00173] The communication system of FIG. 12 as a whole enables connectivity between the connected UEs 1291, 1292 and host computer 1230. The connectivity may be described as an over-the-top (OTT) connection 1250. Host computer 1230 and the connected UEs 1291, 1292 are configured to communicate data and/or signaling via OTT connection 1250, using access network 1211, core network 1214, any intermediate network 1220 and possible further infrastructure (not shown) as intermediaries. OTT connection 1250 may be transparent in the sense that the participating communication devices through which OTT connection 1250 passes are unaware of routing of uplink and downlink communications. For example, base station 1212 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 1230 to be forwarded (e.g., handed over) to a connected UE 1291. Similarly, base station 1212 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1291 towards the host computer 1230.

[00174] Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to FIG. 13. In communication system 1300, host computer 1310 comprises hardware 1315 including communication interface 1316 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 1300. Host computer 1310 further comprises processing circuitry 1318, which may have storage and/or processing capabilities. In particular, processing circuitry 1318 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 1310 further comprises software 1311, which is stored in or accessible by host computer 1310 and executable by processing circuitry 1318. Software 1311 includes host application 1312. Host application 1312 may be operable to provide a service to a remote user, such as UE 1330 connecting via OTT connection 1350 terminating at UE 1330 and host computer 1310. In providing the service to the remote user, host application 1312 may provide user data which is transmitted using OTT connection 1350.

[00175] Communication system 1300 further includes base station 1320 provided in a telecommunication system and comprising hardware 1325 enabling it to communicate with host computer 1310 and with UE 1330. Hardware 1325 may include communication interface 1326 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 1300, as well as radio interface 1327 for setting up and maintaining at least wireless connection 1370 with UE 1330 located in a coverage area (not shown in FIG. 13) served by base station 1320. Communication interface 1326 may be configured to facilitate connection 1360 to host computer 1310. Connection 1360 may be direct or it may pass through a core network (not shown in FIG. 13) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 1325 of base station 1320 further includes processing circuitry 1328, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 1320 further has software 1321 stored internally or accessible via an external connection.

[00176] Communication system 1300 further includes UE 1330 already referred to. Its hardware 1335 may include radio interface 1337 configured to set up and maintain wireless connection 1370 with a base station serving a coverage area in which UE 1330 is currently located. Hardware 1335 of UE 1330 further includes processing circuitry 1338, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 1330 further comprises software 1331, which is stored in or accessible by UE 1330 and executable by processing circuitry 1338. Software 1331 includes client application 1332. Client application 1332 may be operable to provide a service to a human or non-human user via UE 1330, with the support of host computer 1310. In host computer 1310, an executing host application 1312 may communicate with the executing client application 1332 via OTT connection 1350 terminating at UE 1330 and host computer 1310. In providing the service to the user, client application 1332 may receive request data from host application 1312 and provide user data in response to the request data. OTT connection 1350 may transfer both the request data and the user data. Client application 1332 may interact with the user to generate the user data that it provides.

[00177] It is noted that host computer 1310, base station 1320 and UE 1330 illustrated in FIG. 13 may be similar or identical to host computer 1230, one of base stations l2l2a, l2l2b, l2l2c and one of UEs 1291, 1292 of FIG. 12, respectively. This is to say, the inner workings of these entities may be as shown in FIG. 13 and independently, the surrounding network topology may be that of FIG. 12.

[00178] In FIG. 13, OTT connection 1350 has been drawn abstractly to illustrate the communication between host computer 1310 and UE 1330 via base station 1320, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 1330 or from the service provider operating host computer 1310, or both. While OTT connection 1350 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

[00179] Wireless connection 1370 between UE 1330 and base station 1320 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 1330 using OTT connection 1350, in which wireless connection 1370 forms the last segment. More precisely, the teachings of these embodiments may improve the quality of communication between a vehicle and some other thing, such as another vehicle, infrastructure object, or person and thereby provide benefits such as improved safety, traffic management, etc.

[00180] A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 1350 between host computer 1310 and UE 1330, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 1350 may be implemented in software 1311 and hardware 1315 of host computer 1310 or in software 1331 and hardware 1335 of UE 1330, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 1350 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 1311, 1331 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1350 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 1320, and it may be unknown or imperceptible to base station 1320. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer l3l0’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 1311 and 1331 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1350 while it monitors propagation times, errors etc.

[00181] FIG. 14 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to FIGS. 12 and 13. For simplicity of the present disclosure, only drawing references to FIG. 14 will be included in this section. In step 1410, the host computer provides user data. In substep 1411 (which may be optional) of step 1410, the host computer provides the user data by executing a host application. In step 1420, the host computer initiates a transmission carrying the user data to the UE. In step 1430 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1440 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

[00182] FIG. 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to FIGS. 12 and 13. For simplicity of the present disclosure, only drawing references to FIG. 15 will be included in this section. In step 1510 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 1520, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1530 (which may be optional), the UE receives the user data carried in the transmission. [00183] FIG. 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to FIGS. 12 and 13. For simplicity of the present disclosure, only drawing references to FIG. 16 will be included in this section. In step 1610 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 1620, the UE provides user data. In substep 1621 (which may be optional) of step 1620, the UE provides the user data by executing a client application. In substep 1611 (which may be optional) of step 1610, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 1630 (which may be optional), transmission of the user data to the host computer. In step 1640 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

[00184] FIG. 17 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to FIGS. 12 and 13. For simplicity of the present disclosure, only drawing references to FIG. 17 will be included in this section. In step 1710 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 1720 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 1730 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

[00185] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[00186] The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

[00187] Abbreviations

[00188] At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

[00189] lx RTT CDMA2000 lx Radio Transmission Technology

[00190] 3GPP 3rd Generation Partnership Project

[00191] 5G 5th Generation

[00192] ABS Almost Blank Subframe

[00193] AGC Automatic gain control

[00194] ARQ Automatic Repeat Request

[00195] AWGN Additive White Gaussian Noise

[00196] BCCH Broadcast Control Channel

[00197] BCH Broadcast Channel

[00198] CA Carrier Aggregation

[00199] CC Carrier Component

[00200] CCCH SDU Common Control Channel SDU

[00201] CDMA Code Division Multiplexing Access

[00202] CGI Cell Global Identifier

[00203] CIR Channel Impulse Response

[00204] CP Cyclic Prefix

[00205] CPICH Common Pilot Channel [00206] CPICH Ec/No CPICH Received energy per chip divided by the power density in the band

[00207] CQI Channel Quality information

[00208] C-RNTI Cell RNTI

[00209] CSI Channel State Information

[00210] CSI-RS Channel state information reference signal

[00211] D2D Device-to-device communication

[00212] DCCH Dedicated Control Channel

[00213] DL Downlink

[00214] DM Demodulation

[00215] DMRS Demodulation Reference Signal

[00216] DRX Discontinuous Reception

[00217] DTX Discontinuous Transmission

[00218] DTCH Dedicated Traffic Channel

[00219] DUT Device Under Test

[00220] E-CID Enhanced Cell-ID (positioning method)

[00221] E-SMLC Evolved-Serving Mobile Location Centre

[00222] ECGI Evolved CGI

[00223] eNB E-UTRAN NodeB

[00224] ePDCCH enhanced Physical Downlink Control Channel

[00225] E-SMLC evolved Serving Mobile Location Center

[00226] E-UTRA Evolved UTRA

[00227] E-UTRAN Evolved UTRAN

[00228] FDD Frequency Division Duplex

[00229] FFS For Further Study

[00230] GERAN GSM EDGE Radio Access Network

[00231] gNB Base station in NR

[00232] GNSS Global Navigation Satellite System

[00233] GP Guard period

[00234] GSM Global System for Mobile communication

[00235] HARQ Hybrid Automatic Repeat Request

[00236] HO Handover

[00237] HSPA High Speed Packet Access [00238] HRPD High Rate Packet Data

[00239] LOS Line of Sight

[00240] LPP LTE Positioning Protocol

[00241] LTE Long-Term Evolution

[00242] MAC Medium Access Control

[00243] MAC CE MAC control element

[00244] MBMS Multimedia Broadcast Multicast Services

[00245] MBSFN Multimedia Broadcast multicast service Single Frequency Network

[00246] MBSFN ABS MBSFN Almost Blank Subframe

[00247] MCS Modulation and coding schemes

[00248] MDT Minimization of Drive Tests

[00249] MIB Master Information Block

[00250] MME Mobility Management Entity

[00251] MSC Mobile Switching Center

[00252] NPDCCH Narrowband Physical Downlink Control Channel

[00253] NR New Radio

[00254] NW Network

[00255] OCNG OFDMA Channel Noise Generator

[00256] OFDM Orthogonal Frequency Division Multiplexing

[00257] OFDMA Orthogonal Frequency Division Multiple Access

[00258] OSS Operations Support System

[00259] OTDOA Observed Time Difference of Arrival

[00260] O&M Operation and Maintenance

[00261] PBCH Physical Broadcast Channel

[00262] P-CCPCH Primary Common Control Physical Channel

[00263] PCell Primary Cell

[00264] PCFICH Physical Control Format Indicator Channel

[00265] PDCCH Physical Downlink Control Channel

[00266] PDP Profile Delay Profile

[00267] PDSCH Physical Downlink Shared Channel

[00268] PGW Packet Gateway

[00269] PHICH Physical Hybrid- ARQ Indicator Channel

[00270] PLMN Public Land Mobile Network [00271] PMI Precoder Matrix Indicator

[00272] PRACH Physical Random Access Channel

[00273] ProSe Proximity-based services

[00274] PRS Positioning Reference Signal

[00275] PSCCH Physical sidelink control channel

[00276] PSSCH Physical sidelink shared channel

[00277] PSS Primary Synchronization Signal

[00278] PUCCH Physical Uplink Control Channel

[00279] PUSCH Physical Uplink Shared Channel

[00280] RACH Random Access Channel

[00281] QAM Quadrature Amplitude Modulation

[00282] RAN Radio Access Network

[00283] RAT Radio Access Technology

[00284] RLM Radio Link Management

[00285] RNC Radio Network Controller

[00286] RNTI Radio Network Temporary Identifier

[00287] RRC Radio Resource Control

[00288] RRM Radio Resource Management

[00289] RS Reference Signal

[00290] RSCP Received Signal Code Power

[00291] RSRP Reference Symbol Received Power OR

Reference Signal Received Power

[00292] RSRQ Reference Signal Received Quality OR

Reference Symbol Received Quality

[00293] RSSI Received Signal Strength Indicator

[00294] RSTD Reference Signal Time Difference

[00295] SCI Sidelink control information

[00296] SCH Synchronization Channel

[00297] SCell Secondary Cell

[00298] SDU Service Data Unit

[00299] SFN System Frame Number

[00300] SGW Serving Gateway

[00301] SI System Information [00302] SIB System Information Block

[00303] SL-CSI-RS Sidelink CSI-RS

[00304] SNR Signal to Noise Ratio

[00305] SON Self Optimized Network

[00306] SS Synchronization Signal

[00307] SSS Secondary Synchronization Signal

[00308] TDD Time Division Duplex

[00309] TDOA Time Difference of Arrival

[00310] TO A Time of Arrival

[00311] TSS Tertiary Synchronization Signal

[00312] TTI Transmission Time Interval

[00313] UE User Equipment

[00314] UL Uplink

[00315] UMTS Universal Mobile Telecommunication System

[00316] USIM Universal Subscriber Identity Module

[00317] UTDOA Uplink Time Difference of Arrival

[00318] UTRA Universal Terrestrial Radio Access

[00319] UTRAN Universal Terrestrial Radio Access Network

[00320] V2V Vehicle-to-vehicle communication

[00321] V2X Vehicle-to-anything communication

[00322] WCDMA Wide CDMA

[00323] WLAN Wide Local Area Network

[00324]

Claims

CLAIMS What is claimed is:

1. A method performed by a wireless device for providing reference signals for device - to-device communication, the method comprising:

determining, for a first transmission, an allocation of physical resources according to a subframe format that positions one or more reference signals for channel state information at the transmitter, CSIT, in a symbol position that avoids overlap with a data symbol in a concurrent second transmission; and

transmitting the first transmission having the allocation of physical resources accord to the determined subframe format.

2. The method of claim 1, wherein the one or more reference signals comprises an side like channel state information reference signal, SL-CSI-RS, symbol and wherein determining the allocation of physical resources according to the subframe format comprises:

muting a demodulation reference signal, DMRS, symbol and including the SL-CSI- RS symbol in the position of the muted DMRS symbol;

multiplexing the SL-CSI-RS symbol with the DMRS symbol to generate a

multiplexed symbol and transmitting the multiplexed symbol in the position originally used for the DMRS; or

transmitting the SL-CSI-RS in the guard period of the slot.

3. The method of claim 2, wherein multiplexing the SL-CSI-RS symbol with the DMRS symbol comprises utilizing orthogonal sequences for the DMRS symbol and the SL- CSI-RS symbol.

4. The method of claim 3, wherein utilizing orthogonal sequences comprises using

shifted versions of a base sequence.

5. The method of any of claims 1-4, wherein muting the DRMS symbol and including the SL-CSI-RS symbol in the position of the muted DMRS symbol comprises: identifying a plurality of DMRS symbols included in the subframe format, the plurality of DMRS symbols including at least a first DMRS symbol, a last DMRS symbol, and an intermediate DMRS symbol positioned between the first DMRS symbol and the last DMRS symbol;

muting the intermediate DMRS symbol; and

including the SL-CSI-RS symbol in the position of the muted intermediate DMRS symbol.

6. The method of any of any of claims 1-5, wherein the subframe format comprises: a first symbol for automatic gain control, AGC, settling;

2nd and 3rd symbols for a physical sidelink control channel, PSCCH;

7th, lOth, l3th symbols for DMRS;

5th, 6th, 8th, 9th, l lth, l2th symbols for data of the physical sidelink shared channel, PSSCH;

a l4th symbol is for a guard period, GP, and wherein a 4th symbol of carries SL-CSI- RS.

7. The method of any of claims 1-6, wherein the muting the DMRS symbol comprises muting a first DMRS symbol of a plurality of DMRS symbols.

8. The method of any of claims 1-7, where in the method further comprises:

determining a speed of the wireless device;

comparing the speed of the wireless device to a threshold speed;

muting the DMRS symbol when the speed of the wireless device is less than the threshold speed; and

multiplexing the SL-CSI-RS with the DMRS symbol or transmitting the SL-CSI-RS in the guard period when speed of the wireless device is greater than or equal to the threshold speed.

9. The method of any of claims 1-8, further comprising notifying a receiving wireless device of the position of the muted DMR symbol.

10. The method of any of claims 1-9, wherein multiplexing the SL-CSI-RS symbol with the DMRS symbol to generate a multiplexed symbol comprises utilizing a mapping with data or without data.

11. The method of any of claims 1-10, wherein the one or more reference signals

comprises splitting a reference signal sequence p = \p₁, p₂, p₃, , p_N] into a first subsequence, a second subsequence, and a third subsequence by:

generating the first subsequence: P_dmrs = [pi, P3_< Ps_>—_> P_/v-i] for DMRS, to be transmitted at both a first antenna and a second antenna;

generating the second subsequence: PCSIRSI ⁼ [P2_< Pe_>— _> P_/v— 2] f°^r the SL-CSI-RS 1 to be transmitted from the first antenna.

generating the third subsequence: Pcsms ⁼ \V_A> P_{S> >} P_N\ f°^r the SL-CSI-RS2 to be transmitted from the second antenna. ; and

wherein the method further comprises transmitting the first subsequence, the second subsequence, and the third subsequence.

12. The method of any of claims 1-11, wherein transmitting the SL-CSI-RS in the guard period comprises transmitting the SL-CSI-RS the first half of the guard period symbol and not in the second half of the guard period.

13. The method of any of claims 1-12, further comprising:

providing user data; and

forwarding the user data to a host computer via the transmission to the base station.

14. A method performed by a base station for providing reference signals for device-to- device communication, the method comprising:

transmitting an indication to a UE that instructs that UE to:

mute a DMRS symbol and including an SL-CSI-RS symbol in the position of the muted DMRS symbol;

multiplex the SL-CSI-RS symbol with the DMRS symbol to generate a multiplex symbol and transmitting the multiplex symbol in the position originally used for the DMRS; or transmit the SL-CSI-RS in the guard period of the slot; when the UE includes the SL- CSI-RS in a transmission.

15. The method of claim 14, further comprising:

obtaining user data; and

forwarding the user data to a host computer or a wireless device.

16. A wireless device for providing reference signals for device-to-device

communication, the wireless device comprising:

processing circuitry configured to perform operations of:

transmitting the first transmission having the allocation of physical resources accord to the determined subframe format; and

power supply circuitry configured to supply power to the wireless device.

17. A base station for providing reference signals for device-to-device communication, the base station comprising:

processing circuitry configured to perform operations of:

transmitting an indication to a UE that instructs that UE to:

multiplex the SL-CSI-RS symbol with the DMRS symbol to generate a

multiplex symbol and transmitting the multiplex symbol in the position originally used for the DMRS; or

transmit the SL-CSI-RS in the guard period of the slot; when the UE includes the SL-CSI-RS in a transmission; and;

power supply circuitry configured to supply power to the wireless device.

18. A user equipment (UE) for providing reference signals for device-to-device communication, the UE comprising:

an antenna configured to send and receive wireless signals;

radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry, the processing circuitry being configured to perform any of the steps of any of the Group A claims, such as:

muting a DMRS symbol and including the SL-CSI-RS symbol in the position of the muted DMRS symbol;

multiplexing the SL-CSI-RS symbol with the DMRS symbol to generate a multiplex symbol and transmitting the multiplex symbol in the position originally used for the DMRS; or

transmitting the SL-CSI-RS in the guard period of the slot, when including an SL-CSI-RS symbol in a transmission to another UE;

an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry;

an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and

a battery connected to the processing circuitry and configured to supply power to the

UE.