CN108702244B - Link adaptation for low complexity device-to-device (D2D) communication - Google Patents

Abstract

An apparatus for a User Equipment (UE), the apparatus comprising circuitry to set a sidelink transmission Modulation and Coding Scheme (MCS) based on a physical sidelink shared channel reference signal received quality (S-RSRQ), or to set a sidelink transmission power level based on a sidelink path loss. The S-RSRQ may be measured or calculated based on a sidelink received signal strength indication (S-RSSI), a sidelink interference signal strength indication (S-ISSI), and a sidelink reference signal received power (SL-RSRP), while the path loss between the UE and another UE may be derived based on the SL-reference signal power and the SL-RSRP or a sidelink discovery reference signal received power (SD-RSRP).

Description

Link adaptation for low complexity device-to-device (D2D) communication

Cross reference to related applications

Priority of U.S. provisional patent application No.62/317,088 entitled LINK ADAPTATION FOR LOW COMPLEXITY LTE D2D COMMUNICATION filed on 1/4/2016, the entire disclosure of which is incorporated herein by reference.

Technical Field

Embodiments may generally relate to the field of wireless communications.

Background

LTE (long term evolution) networks may provide device-to-device (D2D) communication.

Drawings

The embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. For ease of description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Fig. 1 shows a schematic high-level example of a network comprising a User Equipment (UE) and an evolved nodeb (enb), in accordance with various embodiments;

fig. 2 illustrates example components of a remote UE or relay UE in accordance with various embodiments;

fig. 3 illustrates a UE in accordance with various embodiments;

fig. 4 illustrates a link adaptation process for D2D communication between a remote UE and a relay UE, in accordance with various embodiments;

fig. 5 illustrates another link adaptation procedure for D2D communication between a remote UE and a relay UE, in accordance with various embodiments;

fig. 6 illustrates another link adaptation procedure for D2D communication between a remote UE and a relay UE, in accordance with various embodiments.

Detailed Description

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the claimed embodiments. However, it will be apparent to one skilled in the art having the benefit of the present disclosure that the various aspects of the embodiments and claims may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present embodiment with unnecessary detail.

For the purposes of this disclosure, the phrases "a/B", "a or B" and "a and/or B" mean (a), (B) or (a and B). For the purposes of this disclosure, the phrases "A, B or C" and "A, B and/or C" mean (a), (B), (C), (a and B), (a and C), (B and C), or (A, B and C).

The description may use the phrases "in one embodiment" or "in an embodiment," which may each refer to one or more of the same or different embodiments. Furthermore, the terms "comprising," "including," "having," and the like, as used with respect to embodiments of the present disclosure, are synonymous.

As discussed herein, the term "module" may be used to refer to one or more physical or logical components or elements of a system. In some embodiments, the modules may be different circuits, while in other embodiments, the modules may include multiple circuits.

Device-to-device (D2D) communication refers to radio technologies that enable devices (e.g., UEs) to communicate directly with each other (i.e., without routing data paths through the network infrastructure). When UEs are close to each other, proximity-based services may be provided. The terms D2D, Sidelink (SL), and proximity services (ProSe) are used interchangeably herein.

In 3GPP release (Rel.)12, the initial framework for D2D communication for LTE (LTE D2D) was introduced for public safety use cases and consumer use cases. The framework includes D2D discovery and D2D communication. D2D is supported for discovery for consumer use cases, while D2D communications supported for consumer and public safety use cases are primarily designed for out-of-coverage, partial coverage, and remote voice communications in public safety use cases. In Rel 13, the functionality of UE-to-Network (NW) relaying using layer 3(L3) forwarding is introduced. In addition, out-of-coverage discovery is introduced to assist in UE-to-NW relay discovery and group discovery.

Therefore, LTE D2D as discussed in rel.12/13 does not solve the link adaptation problem, since LTE D2D is primarily designed for broadcast used in public safety applications. In conventional systems, broadcast transmissions do not consider channel quality, but use a pessimistic Modulation and Coding Scheme (MCS) and transmission power level. On the other hand, D2D one-to-one communication may be useful for new devices, such as wearable computing devices and internet of things (IoT) devices. The pessimistic MCS and transmission power levels used in traditional systems may result in low spectrum and energy efficiency for communicating with D2D of wearable devices and IoT devices.

Example embodiments herein provide enhancements to D2D communications, and in particular, D2D communications for wearable computing devices, Machine Type Communication (MTC) devices, and/or IoT devices. More specifically, the example embodiments provide enhancements to D2D communication with link adaptation by determining MCS and transmission power levels based on channel quality between UEs.

Fig. 1 depicts a high-level example of a network 1000. Network 1000 may include two or more UEs, such as UE 120 and UE 130. Either one of the UE 120 and the UE 130 may be a D2D transmitter or a D2D receiver. Network 1000 may also include an eNB, such as eNB 115. In an embodiment, the eNB 115 may be configured to transmit or receive one or more signals to or from the UEs 120 and 130, e.g., via a cellular communication interface Uu as shown by the solid lines in fig. 1. In some embodiments, the network 1000 may be included in a Wide Area Network (WAN), and transmissions between the eNB 115 and the UE 120 or 130 may use resources of the WAN. Additionally, the UEs 120 and 130 may be configured to transmit to or receive from each other one or more signals via the D2D communication interface PC5, as shown by the dashed lines. For example, UEs 120 and 130 may exchange control information through one or more Scheduling Assignment (SA) transmissions and/or data transmissions as explained herein. In an embodiment, the UE 120 or the UE 130 may perform mode switching between the PC5 interface and the Uu interface to communicate in the D2D mode or the cellular mode.

In embodiments, the UE 130 may be a wearable/IoT UE that accesses a network using a relay D2D connection with the UE 120, where the UE 120 may be a non-IoT, e.g., a smartphone, tablet computing device, etc., that acts as a D2D or ProSe relay node. The connection between the wearable/IoT UE 130 and the relay UE 120 may be a "sidelink". wearable/IoT UEs 130 may have the capability to communicate directly with the eNB; however, this capability may be used for special cases and/or for acquiring control information, e.g., attaching to an access network such as an evolved universal terrestrial access network (E-UTRAN).

In an embodiment, regardless of the possible cellular capabilities of the device, the UE 130 may be one of the following D2D capability categories:

TABLE 1

In D2D communications (e.g., communications over a PC5 interface), the UE may share uplink resources with devices connected to the network. In an embodiment, some physical channels may be introduced: a physical side link control channel (PSCCH) carrying control information, and a physical side link shared channel (PSCCH) carrying data. Control information and data may be placed in PSCCH and PSCCH, while discovery information may be carried in a Physical Sidelink Discovery Channel (PSDCH). In addition, a Physical Sidelink Broadcast Channel (PSBCH) may be used to broadcast system sidelink information to UEs.

For legacy systems such as LTE D2D, there may not be any link adaptation mechanism. In contrast, transmissions for broadcast do not consider channel quality. Example embodiments herein may enable link adaptation for unicast D2D communications, which may be beneficial for D2D communications of wearable computing devices and IoT devices.

Example embodiments herein may provide enhancements to D2D communication with link adaptation by determining MCS and transmission power level based on channel quality. In an embodiment, channel quality and conditions may be measured at medium time scales, and the measurement of channel conditions may be used for path loss estimation, transmission power level adjustment, and MCS selection. In medium time scale link adaptation, MCS selection may be performed for a Sidelink Control Information (SCI) period.

The following terms are used herein:

● remote UE-wearable computing device (e.g., a smart watch or health sensor) or IoT/MTC device (e.g., a fixed smart meter), which may communicate with the network via another UE using the D2D air interface. The remote UE may communicate over the Uu air interface, which is the cellular interface between the UE and the eNB. In embodiments, the remote UE may have lower capabilities and may benefit from low power and low cost operation.

● relay UE-a UE capable of relaying traffic from/to the network to/from another UE using the D2D air interface. Examples of relay UEs may include smart phones, tablet computing devices, laptop computers, desktop personal computers, and/or any other similar computing device. The relay UE may be a D2D capable UE and/or a ProSe enabled UE, such that the relay UE is capable of supporting D2D/ProSe direct discovery, communication, and/or acting as a D2D/ProSe UE-to-NW relay.

● relay discovery-procedure for discovery and selection of relay UEs by remote UEs. Relay discovery may also be referred to as "ProSe direct discovery". This process may be performed before control and data is sent on the sidelink.

● a master UE and a slave UE-a master UE may be UEs that may control operations on a direct link with another UE. A slave UE may be a UE that may be controlled by another UE (e.g., a master UE) for resource allocation, scheduling, measurement, and the like. In an embodiment, when the master UE controls the resource allocation of the slave UEs, the master UE may perform measurements and determine MCS and other transmission parameters from the measurements of the channel conditions. In some other embodiments, the MCS used by the master UE for transmission may be reported or provided by the slave UE.

There may be various measurements of channel conditions. For example, sidelink discovery reference signal received power (SD-RSRP) and sidelink reference signal received power (S-RSRP) measurements may be defined on PSDCH and PSBCH, respectively, which may be used for layer 3(L3) relay selection and for synchronization. The S-RSRP may be a linear average of the power contributions of resource elements carrying demodulation reference signals associated with the PSBCH within the central 6 Physical Resource Blocks (PRBs) of the applicable subframe. The S-RSRP may be used for synchronization procedures for partial coverage and out-of-coverage UEs. S-RSRP may not be a suitable measurement for other purposes.

SD-RSRP measurements on PSDCH can be used to set the transmission power level and coarse level MCS in a non-interfering environment. However, SD-RSRP does not take into account the interference level during data transmission in PSCCH and PSCCH. In practice, the PSDCH, PSCCH and PSCCH may typically use different transmission power levels and MCSs, and SD-RSRP measurements may not be sufficient to properly determine the transmission power levels and MCSs used in the PSCCH and PSCCH.

In an embodiment, two additional measurements may be performed to support enhanced medium time scale link adaptation for transmission power level control and MCS selection purposes.

● side link Path Loss (PL)_s)-PL_sMay be a sidelink path loss estimate between two UEs (e.g., a relay UE and a terminal UE, or a remote UE). Due to the reciprocity principle, PL can be measured on either side of the link between two UEs_sThus simplifying the measurement process of the low power wearable device. PL_sMay allow for UE-UE side link specific power control. In an embodiment, PL may be measured on one side of a link_sAnd reports it to the other side of the link. Alternatively, PL may be measured on both sides_s。

● side link reference signal received quality (S-RSRQ) -S-RSRQ may be related to large scale signal to interference plus noise ratio (LS-SINR), and may be used for medium time scale link adaptation to set MCS. The S-RSRQ may also be used for mode switching between Uu and PC5 operations.

Measuring link path loss

PL_sEquation PL may be used_sSL-reference signal power-SL-RSRP. In embodiments, the SL-RSRP and SL-reference signal power may be calculated or obtained in different ways.

In an embodiment, the SL-RSRP may be calculated as SD-RSRP, which may be a linear average of the power contributions of resource elements carrying demodulation reference signals associated with PSDCHs for which Cyclic Redundancy Checks (CRCs) have been verified. In an embodiment, the Energy Per Resource Element (EPRE) of a demodulation reference signal (DMRS) for PSDCH transmission may be signaled from an upper layer before measuring SD-RSRP.

In an embodiment, a new RSRP measured on PSCCH or PSCCH may be performed as SL-RSRP. In an embodiment, the transmission power may be utilized as the cellular power PL_c(eNB-UE path loss) to perform initial transmission of PSCCH and PSCCH. In obtaining side link path loss PL_sThereafter, the transmission power of the sidelink may be changed. In an embodiment, the path may also be measuredThe EPRE of the DMRS for PSCCH/PSCCH is signaled from the upper layer before loss.

Similarly, in embodiments, the SL-reference signal power may be calculated in different ways.

In an embodiment, a predefined power control parameter for transmitting a reference signal may be used as SL-reference signal power. However, in most cases it may be difficult to determine the predefined power control parameters.

In an embodiment, the SL-reference signal power may be signaled in the payload of a certain channel, e.g. in the channel on which the measurements may be performed. For example, the SL-reference signal power may be placed in the PSDCH payload. For this case, PL can be quickly calculated by measuring SD-RSRP and extracting the corresponding SL-reference signal power from the PSDCH payload_s. In an embodiment, SD-RSRP may be measured after CRC passes. In an embodiment, a signal range of (-60.. 50) dBm may be used for the sidelink, which may be represented by up to 7 bits when a 1dBm granularity may be considered.

In embodiments, the SL-reference signal power may be obtained in different ways. For example, instead of SL-reference signal power, SL-RSRP may be received through signaling from upper layers, and then the master UE may calculate SL-reference signal power using the signaled SL-RSRP and the transmission power known from the equation PLs-SL-reference signal power-RSRP. In an embodiment, a master UE may send reference signals for measuring SL-RSRP. Alternatively, in an embodiment, the slave UE may estimate SL-RSRP. In some embodiments, the slave UE may signal SL-RSRP to the master UE. Similarly, the master UE may signal SL-RSRP to the slave UE. The exact decision as to which UE may signal SL-RSRP may depend on the complexity and power consumption aspects of the application.

In an embodiment, PL of a ProSe group can be measured_s. There may be multiple PSDCH sources, so these values may be stored with respect to the respective source identities of the ProSe group. According to the relay discovery procedure, the PSDCH transmission may precede the UE-to-NW relayed communication, so measuring the path loss on the PSDCH may be used forDetermining PL_s。

S-RSRQ

The S-RSRQ may be used for medium time scale link adaptation to set MCS. In addition, the MCS can be fine tuned based on ACK/NACK feedback. In an embodiment, channel characteristics measured by PSSCH, such as SL-RSRP, side link reference signal strength indicator (S-RSSI), and side link interference signal strength indicator (S-ISSI), which can be the interference plus noise component of the S-RSSI, can be used to calculate the S-RSRQ.

The main components for calculating the S-RSRQ may be as follows:

S-RSRQ＝N·SL-RSRP/S-RSSI；

S-RSSI＝N·SL-RSRP+S-ISSI；

LS-SINR is N.SL-RSRP/S-ISSI; and

S-RSRQ＝1/(1+1/LS-SINR)。

● N may be the number of PRBs in the measurement bandwidth.

● SL-RSRP may be measured on PSSCH or calculated using the path loss equation SL-RSRP-SL-reference signal power-PLs, where PLs may be measured using a dedicated procedure and SL-reference signal power may be received from upper layers.

● S-RSSI may be a linear average of the total received power observed in certain OFDM symbols of the measurement subframe over the UE' S N resource blocks from all sources (including co-channel serving and non-serving batteries, adjacent channel interference, thermal noise, etc.). In an embodiment, the S-RSSI may be the sum of all received signals including useful, interference, and noise N · SL-RSRP + S-ISSI, where S-ISSI may be an interference signal strength indication including the interference and noise power measured in bandwidth N.

● in an embodiment, both SL-RSRP and S-RSSI may be measured on the same resource element to obtain consistent results.

In an embodiment, the S-RSRQ may be measured on both sides of the link between two UEs due to different interference on different sides. In an embodiment, the S-RSRQ calculation for both sides may be performed by the master UE when the master UE controls the slave UE.

In an embodiment, various operational procedures may be shown to show how the S-RSRQ may be obtained. There may be more possible operations to obtain a S-RSRQ not shown.

Option 1：

Master ← slave S-RSRQ

The primary UE calculates PLs using SD-RSRP measured on PSDCH as described above.

-the primary UE calculating the pschsl-RSRP. The master UE may determine the SL-reference signal power and PLs by calculating the SL-RSRP using the power control parameter and the resource allocation size of the slave UE. In an embodiment, the master UE may measure SL-RSRP for the actual allocation.

The primary UE measures the S-RSSI/S-ISSI on the PSSCH to determine the S-RSRQ.

Master → slave S-RSRQ:

-the slave UE calculating the S-ISSI on the psch.

-the slave UE reporting the S-ISSI to the master UE.

The primary UE estimates the pschsl-RSRP using the power control parameters and the path loss.

-the master UE calculating S-RSSI using the reported S-ISSI and the calculated SL-RSRP.

-the master UE calculating S-RSRQ.

Option 2:

master → slave S-RSRQ:

the slave UE calculates the S-RSSI on the psch.

-the slave UE reporting the S-RSSI to the master UE.

-the primary UE estimating the pschsl-RSRP based on the power control parameter and the path loss.

-the master UE filters out measurements from the slave UEs that do not contain their useful power. In this way, the master UE can distinguish between S-RSSI and S-ISSI.

-the master UE calculating S-RSSI using the reported S-ISSI and the calculated SL-RSRP.

-the master UE calculating S-RSRQ.

Power control

In an embodiment, the PSCCH and PSSCH may be based on PL_sControl to determine a transmission power level for a UE-UE linkIt may also be referred to as power control or Transmit Power Control (TPC). For example, the following power control equation may be used for the PSSCH in various embodiments. The same or similar equations may be used for PSCCH transmission power control. PL measured on UE-UE link_sCan be used to set the transmission power (if the resulting transmission power does not exceed the use_eLegacy settings for NB-UE path loss parameters).

UE transmission power P for sidelink Transmission mode 1 and PSSCH period i_psschMay be determined by:

p is set to 0 if the TPC command field in the configured sidelink grant for PSCCH period i is set to 0_pssch＝P_CMAX,PSSCH，

If the TPC command field in the configured sidelink grant for PSCCH period i is set to 1, then

For sidelink transmission mode 2, the UE transmission power P_psschMay be determined by:

the notation in the above equation may be as follows:

P_CMAX.PSSCHmay be a linear value of the maximum output power of the total configuration of the UE, M_PSSCHBandwidth of PSSCH resource allocation, P, which may be expressed in terms of a number of resource blocks_{0_PSSCH,1}、P_{0_PSSCH,2}、α_PSSCH,1And alpha_PSSCH,2May be provided by higher layer parameters that may be associated with the respective psch resource configuration, PLs may be as previously defined if parameter X or Y may be signaled, or PLs ∞, PLc previously described if parameter X or Y may not be signaled.

The higher layer signaling parameter X mayThe UE-UE path loss is allowed for power control. Higher layer signaling parameter Δ_c-s(Y) adjusting an offset between a transmission power calculated using the eNB-UE path loss and a transmission power calculated using the UE-UE path loss. If a transmission power adjustment command alpha is received from the control signaling_PSSCCH,1、α_PSSCCH,2、δ_PSSCH,1And delta_PSSCH,2They can be applied.

The path loss measurements PLs may be performed according to the procedure described above. The path loss may be estimated by the transmitting UE or may be obtained from higher layer signaling. The activation flag X and offset value Y may be signaled by the eNB or by the master UE using higher layer signaling. In the case of an eNB, a System Information Block (SIB) or dedicated Radio Resource Control (RRC) may be used for signaling. In an embodiment, the parameters may be signaled to the master UE using a control Medium Access Control (MAC) Protocol Data Unit (PDU) format as further described.

Power control parameter configuration

In an embodiment, the remote UE may have a Uu interface and may read the system information block. Example embodiments may place Open Loop Power Control (OLPC) parameters and new parameters of various embodiments in the SIB 18. In some embodiments, the power control parameters may be provided by the relay UE (master UE) when the remote UE does not have the capability to read the SIB 18.

Measurement request

In an embodiment, a separate MAC Control Element (CE) may be introduced to request measurement reports for the current or upcoming SCI period. The MAC CE may carry a measurement setup ID and a measurement type. The measurement ID may correspond to one of the measurement settings configured in the dedicated D2D RRC message. The measurement type may trigger a MAC CE transmission with an average measurement or a D2D RRC message with an extended measurement.

Measurement reporting

In an embodiment, due to the fixed size of the report, the MAC CE mechanism may be used to provide the average value. The MAC CE may carry a measurement setup ID, a measurement type, a measurement value, and a counter (subframe or SCI period). In an embodiment, 8 bits may be sufficient to report (-60.. 50) dBm at 0.5dBm granularity.

Transmit power adjustment commands

In an embodiment, the TPC commands may also be carried by the MAC CE for multiplexing with the regular data in the pscch channel. In an embodiment, the CE content may include power adjustments for PSCCH, as well as power adjustments for PSCCH.

D2D RRC message for link adaptation

In an embodiment, RRC level signaling using various header formats for the PC5 interface may be implemented to maintain unicast D2D communications. Information that may be exchanged in some embodiments may be described herein.

Measurement setup configuration

In an embodiment, the dedicated D2D RRC message may carry a configuration of subframe measurement settings/patterns. The pattern may be a bitmap or an index vector to indicate subframes in the SCI period in which corresponding measurements may be performed. The mode may be accompanied by a mode ID and measurement type (or types) that may be reported for the current setting/mode.

Measurement reporting

In an embodiment, when the RRC mechanism of D2D is available, time frequency selective measurements on different settings and modes may be reported by D2D RRC messages.

PSDCH changes

In an embodiment, PL may be calculated by PLs-SL-reference signal power-SL-RSRP. In an embodiment, the SL-RSRP may be calculated as SD-RSRP, and the EPRE of the DMRS for PSDCH transmission may be signaled from upper layers before measuring SD-RSRP. For path loss calculations using EPRE for DMRS, there may be different options for the PSDCH to carry the identified information.

In an embodiment, a MAC PDU format for sidelink discovery channel (SL-DCH) may be introduced. In conventional systems, the transparent MAC mode may be used for SL-DCH transmission, i.e. MAC Service Data Units (SDUs) may be bypassed without modification of the physical layer, and only higher layer information may be carried in the discovery message. In this case, the described information may be multiplexed into the discovery message using the MAC CE subheader and corresponding information.

In an embodiment, the RRC message may be carried by a SL-DCH MAC SDU. In which case the MAC transparent mode can be reused.

The embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. FIG. 2 illustrates example components of the electronic device 100 of an embodiment. In embodiments, the electronic device 100 may be an implementation that is incorporated or otherwise as part of the MTC UE described herein. In some embodiments, electronic device 100 may include application circuitry 102, baseband circuitry 104, Radio Frequency (RF) circuitry 106, front-end module (FEM) circuitry 108, and one or more antennas 110 coupled together at least as shown.

As used herein, the term circuitry may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or combination) and/or memory (shared, dedicated, or combination) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or the functions associated with, one or more software or firmware modules. In some embodiments, the circuitry may comprise logic operable, at least in part, in hardware.

The application circuitry 102 may include one or more application processors. For example, the application circuitry 102 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

The baseband circuitry 104 may include circuitry such as, but not limited to: one or more single-core or multi-core processors. Baseband circuitry 104 may include one or more baseband processors and/or control logic to process baseband signals received from the receive signal path of RF circuitry 106 and to generate baseband signals for the transmit signal path of RF circuitry 106. Baseband circuitry 104 may interface with application circuitry 102 to generate and process baseband signals and to control the operation of RF circuitry 106. For example, in some embodiments, the baseband circuitry 104 may include a second generation (2G) baseband processor 104a, a third generation (3G) baseband processor 104b, a fourth generation (4G) baseband processor 104c, and/or one or more other baseband processors 104d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 104 (e.g., one or more of the baseband processors 104 a-d) may handle various radio control functions that support communication with one or more radio networks via the RF circuitry 106. The radio control functions may include, but are not limited to: signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 104 may include Fast Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, the encoding/decoding circuitry of baseband circuitry 104 may include convolution, tail-biting convolution, turbo, Viterbi (Viterbi), and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functions are not limited to these examples, and other suitable functions may be included in other embodiments.

In some embodiments, the baseband circuitry 104 may include elements of a protocol stack, e.g., elements of an evolved universal terrestrial radio access network (E-UTRAN) protocol, including, for example: physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and/or radio link control (RRC) elements. A Central Processing Unit (CPU)104e of the baseband circuitry 104 may be configured to run elements of a protocol stack for signaling of the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio Digital Signal Processors (DSPs) 104 f. The audio DSP(s) 104f may include elements for compression/decompression and echo cancellation, and may include other suitable processing elements in other embodiments.

The baseband circuitry 104 may also include memory/storage 104 g. The memory/storage 104g may be used to load and store data and/or instructions for operations performed by the processor of the baseband circuitry 104. The memory/storage for one embodiment may comprise any combination of suitable volatile memory and/or non-volatile memory. Memory/storage 104g may include any combination of various levels of memory/storage, including but not limited to: read Only Memory (ROM) with embedded software instructions (e.g., firmware), random access memory (e.g., Dynamic Random Access Memory (DRAM)), cache, buffers, and so forth. The memory/storage 104g may be shared among various processors or dedicated to a particular processor.

In some embodiments, components of the baseband circuitry may be combined in a single chip, a single chipset, or disposed on the same circuit board, as appropriate. In some embodiments, some or all of the constituent components of baseband circuitry 104 and application circuitry 102 may be implemented together, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 104 may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 104 may support communication with E-UTRAN and/or other Wireless Metropolitan Area Networks (WMANs), WLANs, Wireless Personal Area Networks (WPANs). Embodiments in which the baseband circuitry 104 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 106 may support communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 106 may include switches, filters, amplifiers, and the like to facilitate communication with the wireless network. RF circuitry 106 may include a receive signal path that may include circuitry to down-convert RF signals received from FEM circuitry 108 and provide baseband signals to baseband circuitry 104. RF circuitry 106 may also include a transmit signal path that may include circuitry to up-convert baseband signals provided by baseband circuitry 104 and provide RF output signals to FEM circuitry 108 for transmission.

In some embodiments, RF circuitry 106 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 106 may include a mixer circuit 106a, an amplifier circuit 106b, and a filter circuit 106 c. The transmit signal path of the RF circuitry 106 may include a filter circuit 106c and a mixer circuit 106 a. The RF circuitry 106 may also include synthesizer circuitry 106d for synthesizing frequencies for use by the mixer circuitry 106a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 106a of the receive signal path may be configured to down-convert the RF signal received from the FEM circuitry 108 based on the synthesized frequency provided by the synthesizer circuitry 106 d. The amplifier circuit 106b may be a Low Pass Filter (LPF) or a Band Pass Filter (BPF) configured to remove unwanted signals from the downconverted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 104 for further processing. In some embodiments, the output baseband signal may be a zero frequency baseband signal, but this is not required. In some embodiments, mixer circuit 106a of the receive signal path may comprise a passive mixer, although the scope of the embodiments is not limited in this respect.

In some embodiments, mixer circuitry 106a of the transmit signal path may be configured to upconvert the input baseband signal based on a synthesis frequency provided by synthesizer circuitry 106d to generate an RF output signal for FEM circuitry 108. The baseband signal may be provided by the baseband circuitry 104 and may be filtered by the filter circuitry 106 c. Filter circuit 106c may include a Low Pass Filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may comprise two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 106a of the receive signal path and the mixer circuit 106a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, RF circuitry 106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry, and baseband circuitry 104 may include a digital baseband interface to communicate with RF circuitry 106.

In some embodiments, synthesizer circuit 106d may be a fractional-N synthesizer or a fractional-N/N +1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuit 106d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase locked loop with a frequency divider.

The synthesizer circuit 106d may be configured to synthesize an output frequency for use by the mixer circuit 106a of the RF circuit 106 based on the frequency input and the divider control input. In some embodiments, the synthesizer circuit 106d may be a fractional-N/N +1 synthesizer.

In some embodiments, the frequency input may be provided by a Voltage Controlled Oscillator (VCO), but this is not required. The divider control input may be provided by baseband circuitry 104 or application circuitry 102 depending on the desired output frequency. In some embodiments, the divider control input (e.g., N) may be determined from a look-up table based on the channel indicated by application circuitry 102.

Synthesizer circuit 106d of RF circuit 106 may include a frequency divider, a Delay Locked Loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the divider may be a dual-mode divider (DMD) and the phase accumulator may be a digital phase accumulator (DP a). In some embodiments, the DMD may be configured to divide an input signal by N or N +1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, a DLL may include a set of cascaded, tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to decompose the VCO period into Nd equal phase groups, where Nd is the number of delay elements in the delay line. In this manner, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuit 106d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used with a quadrature generator and divider circuit to generate a plurality of signals having a plurality of mutually different phases at the carrier frequency. In some embodiments, the output frequency may be the LO frequency (fLO). In some embodiments, the RF circuitry 106 may include an IQ/polarity converter.

FEM circuitry 108 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more antennas 110, amplify the received signals, and provide amplified versions of the received signals to RF circuitry 106 for further processing. FEM circuitry 108 may also include a transmit signal path, which may include circuitry configured to amplify signals provided by RF circuitry 106 for transmission by one or more of one or more antennas 110.

In some embodiments, FEM circuitry 108 may include TX/RX switches to switch between transmit mode and receive mode operation. FEM circuitry 108 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a Low Noise Amplifier (LNA) to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to the RF circuitry 106). The transmit signal path of the FEM circuitry 108 may include: a Power Amplifier (PA) for amplifying an input RF signal (e.g., provided by RF circuitry 106) and one or more filters for generating RF signals for subsequent transmission (e.g., by one or more of antennas 110).

In some embodiments, electronic device 100 may include additional elements, such as memory/storage, a display, a camera, sensors, and/or input/output (I/O) interfaces.

In embodiments in which the electronic device 100 is, implements, or is incorporated into or otherwise belongs to a User Equipment (UE), the baseband circuitry 104 may determine a side link path loss between the first UE and the second UE; and setting at least one of a Modulation and Coding Scheme (MCS) or a sidelink transmission power level based at least in part on the sidelink path loss. The RF circuitry 106 may transmit signals based at least in part on the MCS or the sidelink transmission power level.

In some embodiments, baseband circuitry 104 may determine the sidelink path loss based at least in part on a sidelink reference signal received power (SL-RSRP). In various embodiments, the baseband circuitry may determine the sidelink path loss based at least in part on the received indication of the sidelink reference signal power (SL-reference signal power). In some embodiments, the first UE may be a remote UE and the second UE may be a relay UE.

Fig. 3 illustrates a UE or eNB according to some embodiments. The device may be a D2D UE or eNB configured to operate as or with a low power wearable device or IoT device. Control circuit 301 may control various communication operations as described herein, and may also control the transmission and reception of signals by the transmit/receive chains. The transmit/receive chain 303 may be a single transceiver chain.

In implementations where the electronic device shown in fig. 2 is used to implement the UE shown in fig. 3, the control circuitry 301 may be implemented in part of the baseband circuitry 104 and the transmit/receive chain 303 may be implemented in part of the RF circuitry 106 and/or the FEM circuitry 108. In an embodiment, the control circuitry 301 may determine a sidelink path loss between the UE and another UE; and sets a Modulation and Coding Scheme (MCS) or a sidelink transmission power level based on the sidelink path loss. In an embodiment, the transmit/receive chain 303 may transmit/receive signals based on MCS or sidelink transmission power levels.

In some embodiments, the electronic devices of fig. 2-3 may be configured to perform one or more processes, techniques, and/or methods, or portions thereof, as described herein. Fig. 4-6 depict details of some of these processes, techniques, and/or methods.

Fig. 4 illustrates a process 400 according to some embodiments. Process 400 may be performed by a UE (e.g., UE 120 or UE 130 of fig. 1). In some embodiments, the UE may include or have access to one or more non-transitory computer-readable media having instructions stored thereon that, when executed, cause the UE to perform process 400. In some embodiments, process 400 may be performed by baseband circuitry 104 of fig. 2 or control circuitry 301 of fig. 3. The baseband circuitry 104 or the control circuitry 301 may perform the operations of the process 400 directly or may cause one or more other components to perform some or all of the operations of the process 400.

For example, the process may include determining, at 401, a sidelink path loss between the first UE and the second UE by the baseband circuitry 104 of fig. 2 or the control circuitry 301 of fig. 3. In an embodiment, the baseband circuitry 104 or the control circuitry 301 determines the sidelink path loss based on a sidelink discovery reference signal received power (SD-RSRP) or a sidelink reference signal received power (SL-RSRP) measured on a Physical Sidelink Control Channel (PSCCH) or a physical sidelink shared channel (pscsch).

Process 400 may also include, at 402, adapting, by baseband circuitry 104 of fig. 2 or control circuitry 301 of fig. 3, a link for sidelink communications based at least in part on a sidelink path loss. In an embodiment, adjusting the link for the side link communication may include setting a Modulation and Coding Scheme (MCS) by the baseband circuitry 104 or the control circuitry 301 based at least in part on the side link path loss. In some embodiments, adapting the link for sidelink communications may include setting a sidelink transmission power level based at least in part on a sidelink path loss.

Fig. 5 illustrates a process 500 according to some embodiments. Process 500 may be performed by a UE (e.g., UE 120 or UE 130 of fig. 1). In some embodiments, the UE may include or have access to one or more non-transitory computer-readable media having instructions stored thereon that, when executed, cause the UE to perform process 500. In some embodiments, process 500 may be performed by baseband circuitry 104 of fig. 2 or control circuitry 301 of fig. 3. The baseband circuitry 104 or the control circuitry 301 may perform the operations of the process 500 directly or may cause one or more other components to perform some or all of the operations of the process 500.

For example, the electronic devices of fig. 2-3 may: measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI) by the baseband circuitry 104 (501); measuring a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH) (503); determining a physical sidelink shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP (505); setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ (507); and transmits the signal according to the MCS (509).

Fig. 6 illustrates a process 600 according to some embodiments. Process 400 may be performed by a UE (e.g., UE 120 or UE 130 of fig. 1). In some embodiments, the UE may include or have access to one or more non-transitory computer-readable media having instructions stored thereon that, when executed, cause the UE to perform process 600. In some embodiments, process 600 may be performed by baseband circuitry 104 of fig. 2 or control circuitry 301 of fig. 3. The baseband circuitry 104 or the control circuitry 301 may perform the operations of the process 600 directly by the processing circuitry within the baseband circuitry 104 or the control circuitry 301 or may cause one or more other processing circuitry to perform some or all of the operations of the process 600.

For example, the electronic devices of fig. 2-3 may: determining, by the baseband circuitry 104, a side link reference signal power (SL-reference signal power) from the received indication of SL-reference signal power (601); measuring a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH) (603); determining a sidelink path loss between the UE and another UE based on the SL-reference signal power and the SL-RSRP or the SD-RSRP (605); and sets a sidelink transmission power level based on the sidelink path loss (607).

Examples of the invention

Example 1 may include a User Equipment (UE) for device-to-device (D2D) communication in a mobile communication network, comprising:

a baseband circuit to:

determining a sidelink path loss between the UE and another UE; and

setting a Modulation and Coding Scheme (MCS) or a sidelink transmission power level based on a sidelink path loss; and

radio Frequency (RF) circuitry coupled to the baseband circuitry to transmit signals based on the MCS or side link transmission power level.

Example 2 may include the UE of example 1 and/or some other example herein, wherein the baseband circuitry is to determine the sidelink path loss based on a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) measured on a Physical Sidelink Control Channel (PSCCH) or a physical sidelink shared channel (PSCCH).

Example 3 may include the UE of example 1 and/or some other example herein, wherein the baseband circuitry is to determine the sidelink path loss based on a received indication of sidelink reference signal power (SL-reference signal power).

Example 4 may include the UE of example 3 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS)

Example 5 may include the UE of any one of examples 1-4 and/or some other example herein, the baseband circuitry to determine the sidelink path loss based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 6 may include the UE of any one of examples 1-4 and/or some other example herein, wherein:

the baseband circuit is further configured to measure a physical sidelink shared channel reference signal received quality (S-RSRQ), a sidelink received signal strength indication (S-RSSI), or a sidelink interference signal strength indication (S-ISSI); and

the RF circuitry is also to send a measurement signal reporting S-RSRQ, S-RSSI, or S-ISSI to another UE.

Example 7 may include the UE of example 6 and/or some other example herein, wherein the S-RSRQ is calculated based on an S-RSSI, an S-ISSI, and a sidelink reference signal received power (SL-RSRP) measured on a Physical Sidelink Shared Channel (PSSCH).

Example 8 may include the UE of example 7 and/or some other example herein, wherein the S-RSSI or S-ISSI is received from another UE, and the S-RSSI or S-ISSI is measured by or calculated by the other UE.

Example 9 may include the UE of any one of examples 6-7 and/or some other example herein, wherein the RF circuitry is to transmit the measurement signal using a Medium Access Control (MAC) Control Element (CE) or a Radio Resource Control (RRC) message.

Example 10 may include the UE of example 9 and/or some other example herein, the RF circuitry to transmit the measurement signal using a MAC CE, the MAC CE to include a measurement Identifier (ID), a measurement type, a counter, or an average measurement.

Example 11 may include a computer-readable medium comprising instructions that, when executed by one or more processors, cause a User Equipment (UE) to:

measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

measuring a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

determining a physical sidelink shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

so that the signal is transmitted according to the MCS.

Example 12 may include the computer-readable medium of example 11 and/or some other example herein, wherein the instructions, when executed by the processor, further cause the UE to:

the side link discovery reference signal received power (SD-RSRP) is measured.

Example 13 may include the computer-readable medium of any one of examples 11-12 and/or some other example herein, wherein the instructions, when executed by the processor, further cause the UE to:

a side link reference signal power (SL-reference signal power) is determined based on the received indication.

Example 14 may include the computer-readable medium of example 13 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS).

Example 15 may include the computer-readable medium of any one of examples 11-14 and/or some other example herein, wherein the instructions, when executed by the processor, further cause the UE to:

determining a sidelink path loss between the UE and another UE based on the SL-RSRP or SD-RSRP and the SL-reference signal power;

setting a side link transmission power level based on the side link path loss; and

the second signal is transmitted according to the sidelink transmission power level.

Example 16 may include the computer-readable medium of example 15 and/or some other example herein, wherein the sidelink path loss is determined based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 17 may include the computer-readable medium of example 11 and/or some other example herein, wherein the instructions, when executed by the processor, further cause the UE to:

a measurement signal is caused to be transmitted using a Medium Access Control (MAC) Control Element (CE) or a Radio Resource Control (RRC) message, the measurement signal reporting S-RSSI, S-ISSI, or measured S-RSRQ.

Example 18 may include the computer-readable medium of example 17 and/or some other example herein, wherein the measurement signal is transmitted using a MAC CE that includes a measurement Identifier (ID) and a measurement type.

Example 19 may include the computer-readable medium of example 17 and/or some other example herein, wherein the measurement signal is transmitted using a MAC CE, the MAC CE including an average measurement, a measurement Identifier (ID), a measurement type, and a counter.

Example 20 may include an apparatus for use in a User Equipment (UE) for device-to-device (D2D) communication in a mobile communication network, comprising:

a memory storing instructions; and

processing circuitry to execute instructions stored in memory to:

determining a side link reference signal power (SL-reference signal power) from the received indication of SL-reference signal power;

measuring a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

determining a sidelink path loss between the UE and another UE based on the SL-reference signal power and the SL-RSRP or the SD-RSRP; and

the sidelink transmission power level is set based on the sidelink path loss.

Example 21 may include the apparatus of example 20 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS).

Example 22 may include the apparatus of any one of examples 20-21 and/or some other example herein, the processing circuitry to determine the sidelink path loss based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 23 may include the apparatus of any one of examples 20-22 and/or some other example herein, wherein:

the processing circuit is further to:

measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

measuring or calculating a physical side link shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a side link transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

the device also includes:

radio Frequency (RF) circuitry to transmit signals based on the MCS.

Example 24 may include the apparatus of example 23 and/or some other example herein, wherein the RF circuitry is further to transmit the measurement signal reporting the S-RSSI or S-ISSI using a Medium Access Control (MAC) Control Element (CE) comprising a measurement Identifier (ID) and a measurement type, or using a Radio Resource Control (RRC) message.

Example 25 may include the apparatus of any one of examples 20-24 and/or some other example herein, wherein the UE is a remote UE or a relay UE.

Example 26 may include an apparatus for device-to-device (D2D) communication in a mobile communication network, comprising:

means for determining a sidelink path loss between the UE and another UE; and

means for setting a Modulation and Coding Scheme (MCS) or a sidelink transmission power level based on a sidelink path loss; and

means for transmitting a signal based on the MCS or a sidelink transmission power level.

Example 27 may include the apparatus of example 26 and/or some other example herein, wherein means for determining the sidelink path loss comprises means for determining the sidelink path loss based on a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) measured on a Physical Sidelink Control Channel (PSCCH) or a physical sidelink shared channel (PSCCH).

Example 28 may include the apparatus of example 26 and/or some other example herein, wherein means for determining the sidelink path loss comprises means for determining the sidelink path loss based on a received indication of sidelink reference signal power (SL-reference signal power).

Example 29 may include the apparatus of example 28 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS).

Example 30 may include the apparatus of any one of examples 26-29 and/or some other example herein, wherein means for determining a sidelink path loss comprises means for determining a sidelink path loss based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 31 may include the apparatus of any one of examples 26-29 and/or some other example herein, further comprising:

means for measuring a physical sidelink shared channel reference signal received quality (S-RSRQ), a sidelink received signal strength indication (S-RSSI), or a sidelink interference signal strength indication (S-ISSI); and

means for sending a measurement signal reporting S-RSRQ, S-RSSI, or S-ISSI to another UE.

Example 32 may include the apparatus of example 31 and/or some other example herein, wherein the S-RSRQ is calculated based on an S-RSSI, an S-ISSI, and a sidelink reference signal received power (SL-RSRP) measured on a Physical Sidelink Shared Channel (PSSCH).

Example 33 may include the apparatus of example 32 and/or some other example herein, wherein the S-RSSI or S-ISSI is received from another UE, the S-RSSI or S-ISSI being measured by or calculated by the other UE.

Example 34 may include the apparatus of any one of examples 32-33 and/or some other example herein, wherein the means for transmitting the measurement signal comprises means for transmitting the measurement signal using a Medium Access Control (MAC) Control Element (CE) or a Radio Resource Control (RRC) message.

Example 35 may include the apparatus of example 34 and/or some other example herein, wherein the means for transmitting the measurement signal comprises means for transmitting the measurement signal using a MAC CE, the MAC CE comprising a measurement Identifier (ID), a measurement type, a counter, or an average measurement.

Example 36 may include an apparatus for device-to-device (D2D) communication in a mobile communication network, comprising:

means for measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

means for measuring a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

means for determining a physical sidelink shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP;

means for setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

means for causing the signal to be transmitted according to the MCS.

Example 37 may include the apparatus of example 36 and/or some other example herein, further comprising:

means for measuring a sidelink discovery reference signal received power (SD-RSRP).

Example 38 may include the apparatus of any one of examples 36-37 and/or some other example herein, further comprising:

means for determining a side link reference signal power (SL-reference signal power) based on the received indication.

Example 39 may include the apparatus of example 38 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS).

Example 40 may include the apparatus of any one of examples 36-39 and/or some other example herein, further comprising:

means for determining a sidelink path loss between the UE and another UE based on the SL-RSRP or SD-RSRP and the SL-reference signal power;

means for setting a sidelink transmission power level based on a sidelink path loss; and

means for transmitting a second signal according to the sidelink transmission power level.

Example 41 may include the apparatus of example 40 and/or some other example herein, wherein the sidelink path loss is determined based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 42 may include the apparatus of example 36 and/or some other example herein, further comprising:

means for causing a measurement signal reporting S-RSSI, S-ISSI, or measured S-RSRQ to be transmitted using a Medium Access Control (MAC) Control Element (CE) or a Radio Resource Control (RRC) message.

Example 43 may include the apparatus of example 42 and/or some other example herein, wherein the means for causing the measurement signal to be transmitted comprises means for transmitting the measurement signal using a MAC CE that includes a measurement Identifier (ID) and a measurement type.

Example 44 may include the apparatus of example 42 and/or some other example herein, wherein the means for causing the measurement signal to be transmitted comprises means for transmitting the measurement signal using a MAC CE comprising an average measurement, a measurement Identifier (ID), a measurement type, and a counter.

Example 45 may include an apparatus for device-to-device (D2D) communication in a mobile communication network, comprising:

means for determining a side link reference signal power (SL-reference signal power) from the received indication of SL-reference signal power;

means for measuring a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

means for determining a side link path loss between a User Equipment (UE) and another UE based on the SL-reference signal power and the SL-RSRP or the SD-RSRP; and

means for setting a sidelink transmission power level based on a sidelink path loss.

Example 46 may include the apparatus of example 45 and/or some other example herein, wherein the indication of the received SL-reference signal power is signaled in a Physical Sidelink Discovery Channel (PSDCH) payload as an Energy Per Resource Element (EPRE) of a sidelink demodulation reference signal (DMRS).

Example 47 may include the apparatus of any one of examples 45-46 and/or some other example herein, further comprising:

means for determining a sidelink path loss based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 48 may include the apparatus of any one of examples 45-47 and/or some other example herein, further comprising:

means for measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

means for measuring or calculating a physical side link shared channel reference signal received quality (S-RSRQ) based on S-RSSI, S-ISSI, and SL-RSRP;

means for setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

means for transmitting a signal based on the MCS.

Example 49 may include the apparatus of example 48 and/or some other example herein, further comprising:

means for transmitting a measurement signal reporting S-RSSI or S-ISSI using a Medium Access Control (MAC) Control Element (CE) including a measurement Identifier (ID) and a measurement type or using Radio Resource Control (RRC) information.

Example 50 may include the apparatus of any one of examples 45-49 and/or some other example herein, wherein the UE is a remote UE or a relay UE.

Example 51 may include a method for device-to-device (D2D) communication in a mobile communication network, comprising:

determining a sidelink path loss between the UE and another UE; and

setting a Modulation and Coding Scheme (MCS) or a sidelink transmission power level based on a sidelink path loss; and

the signal is transmitted based on the MCS or the sidelink transmission power level.

Example 52 may include the method of example 51 and/or some other example herein, further comprising:

measuring a physical sidelink shared channel reference signal received quality (S-RSRQ), a sidelink received signal strength indication (S-RSSI), or a sidelink interference signal strength indication (S-ISSI); and

sending a measurement signal reporting S-RSRQ, S-RSSI, or S-ISSI to another UE.

Example 53 may include a method for device-to-device (D2D) communication in a mobile communication network, comprising:

measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

measuring a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

determining a physical sidelink shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

such that the signal is transmitted based on the MCS.

Example 54 may include the method of example 53 and/or some other example herein, further comprising:

the side link discovery reference signal received power (SD-RSRP) is measured.

Example 55 may include the method of any one of examples 53-54 and/or some other example herein, further comprising:

a side link reference signal power (SL-reference signal power) is determined based on the received indication.

Example 56 may include the method of any one of examples 53-55 and/or some other example herein, further comprising:

determining a side link path loss based on the SL-RSRP or SD-RSRP and the SL-reference signal power;

setting a sidelink transmission power level based on a sidelink path loss; and

the second signal is transmitted based on the sidelink transmission power level.

Example 57 may include the method of example 53 and/or some other example herein, further comprising:

measurement signals reporting S-RSSI, S-ISSI, or measured S-RSRQ are transmitted using a Medium Access Control (MAC) Control Element (CE) or Radio Resource Control (RRC) message.

Example 58 may include a method for device-to-device (D2D) communication in a mobile communication network, comprising:

determining a side link reference signal power (SL-reference signal power) from the received SL-reference signal power;

measuring a sidelink discovery reference signal received power (SD-RSRP), or a sidelink reference signal received power (SL-RSRP) on a Physical Sidelink Control Channel (PSCCH) or a Physical Sidelink Shared Channel (PSSCH);

determining a sidelink path loss between a User Equipment (UE) and another UE based on the SL-reference signal power and the SL-RSRP or the SD-RSRP; and

the sidelink transmission power level is set based on the sidelink path loss.

Example 59 may include the method of example 58 and/or some other example herein, further comprising:

the sidelink path loss is determined based on a first link from the UE to another UE or a second link from another UE to the UE.

Example 60 may include the method of any one of examples 58-59 and/or some other example herein, further comprising:

measuring a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI);

measuring or calculating a physical side link shared channel reference signal received quality (S-RSRQ) based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a sidelink transmission Modulation and Coding Scheme (MCS) based on the S-RSRQ; and

the signal is transmitted based on the MCS.

Example 61 may include the method of example 58 and/or some other example herein, further comprising:

the measurement signal reporting the S-RSSI or S-ISSI is transmitted using a Medium Access Control (MAC) Control Element (CE) including a measurement Identifier (ID) and a measurement type or using a Radio Resource Control (RRC) message.

The foregoing description of one or more embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

Claims (13)

1. A user equipment, UE, for device-to-device, D2D, communication in a mobile communication network, comprising:

a baseband circuit to:

determining a sidelink path loss and a physical sidelink shared channel reference signal received quality, S-RSRQ, between the UE and another UE associated with a physical sidelink control channel, PSCCH, or a physical sidelink shared channel, PSSCH, respectively, based on a sidelink reference signal received power, SL-RSRP, measured on the physical sidelink control channel, PSCCH, or physical sidelink shared channel, PSSCH, between the UE and the another UE;

setting a sidelink transmission power level for the PSCCH or the PSSCH between the UE and the other UE based on the sidelink path loss; and

setting a Modulation and Coding Scheme (MCS) for the PSCCH or the PSSCH between the UE and the other UE based on the S-RSRQ; and

radio Frequency (RF) circuitry coupled with the baseband circuitry to transmit signals to the other UE based on the MCS and the side link transmission power level.

2. The UE of claim 1, wherein the baseband circuitry is to determine the sidelink path loss based on the received indication of sidelink reference signal power, SL-reference signal power.

3. The UE according to claim 2, wherein the indication of the received SL-reference signal power is signaled in a physical sidelink discovery channel, PSDCH, payload as an energy per resource element, EPRE, of a sidelink demodulation reference signal, DMRS.

4. The UE of any of claims 1 to 3, wherein the baseband circuitry is to determine the sidelink path loss based on a first link from the UE to the other UE or a second link from the other UE to the UE.

5. The UE of any of claims 1 to 3, wherein:

the baseband circuitry is further to measure a side link received signal strength indication (S-RSSI) and a side link interference signal strength indication (S-ISSI), and to determine the S-RSRQ based on the S-RSSI and the S-ISSI; and

the RF circuitry is further to send a signal reporting the S-RSRQ, the S-RSSI, or the S-ISSI to the other UE.

6. An apparatus for use in a user equipment, UE, for device-to-device, D2D, communication in a mobile communication network, comprising:

a memory storing instructions; and

processing circuitry to execute instructions stored in the memory to:

determining a side link reference signal power, SL-reference signal power, from the received indication of SL-reference signal power;

measuring a side link reference signal received power, SL-RSRP, on a physical side link control channel, PSCCH, or a physical side link shared channel, PSSCH, between the UE and another UE;

determining a sidelink path loss between the UE and the other UE associated with the PSCCH or the PSSCH, respectively, based on the SL-reference signal power and the SL-RSRP;

setting a sidelink transmission power level for the PSCCH or the PSSCH between the UE and the other UE based on the sidelink path loss;

measuring a side link received signal strength indicator (S-RSSI) and a side link interference signal strength indicator (S-ISSI);

measuring or calculating a physical sidelink shared channel reference signal received quality, S-RSRQ, based on the S-RSSI, the S-ISSI, and the SL-RSRP; and

setting a sidelink transmission Modulation and Coding Scheme (MCS) for the PSCCH or the PSSCH between the UE and the other UE based on the S-RSRQ.

7. The apparatus according to claim 6, wherein the indication of the received SL-reference signal power is signaled in a physical sidelink discovery channel, PSDCH, payload as an energy per resource element, EPRE, of a sidelink demodulation reference signal, DMRS.

8. The apparatus of any of claims 6-7, wherein the processing circuitry is to determine the sidelink path loss based on a first link from the UE to the other UE or a second link from the other UE to the UE.

9. The apparatus of any of claims 6-7, further comprising:

radio Frequency (RF) circuitry to transmit a signal to the other UE based on the MCS and the side link transmission power level.

10. The apparatus of claim 9, wherein the RF circuitry is further to transmit a measurement signal reporting the S-RSSI or the S-ISSI using a medium access control, MAC, control element, CE, comprising a measurement identifier, ID, and a measurement type, or using a radio resource control, RRC, message.

11. A method for a user equipment, UE, to communicate with another UE device-to-device, D2D, in a mobile communications network, comprising:

measuring a side link received signal strength indicator (S-RSSI) and a side link interference signal strength indicator (S-ISSI);

measuring a side link reference signal received power, SL-RSRP, on a physical side link control channel, PSCCH, or a physical side link shared channel, PSSCH, between the UE and the other UE;

determining a physical sidelink shared channel reference signal received quality, S-RSRQ, based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a sidelink transmission Modulation and Coding Scheme (MCS) for the PSCCH or the PSSCH between the UE and the other UE based on the S-RSRQ;

determining a side link reference signal power, SL-reference signal power, based on the received indication;

determining a sidelink path loss between the UE and the other UE associated with the PSCCH or the PSSCH, respectively, based on the SL-RSRP and the SL-reference signal power;

setting a sidelink transmission power level for the PSCCH or the PSSCH between the UE and the other UE based on the sidelink path loss; and

causing a signal to be transmitted from the UE to the other UE based on the MCS and the side link transmission power level.

12. A computer-readable medium comprising instructions that, when executed by one or more processors, cause a user equipment, UE, to:

measuring a side link received signal strength indicator (S-RSSI) and a side link interference signal strength indicator (S-ISSI);

measuring a side link reference signal received power, SL-RSRP, on a physical side link control channel, PSCCH, or a physical side link shared channel, PSSCH, between the UE and another UE;

determining a physical sidelink shared channel reference signal received quality, S-RSRQ, based on the S-RSSI, the S-ISSI, and the SL-RSRP;

setting a side link transmission Modulation and Coding Scheme (MCS) for the PSCCH or the PSSCH between the UE and another UE based on the S-RSRQ;

determining a side link reference signal power, SL-reference signal power, based on the received indication;

determining a sidelink path loss between the UE and the other UE associated with the PSCCH or the PSSCH, respectively, based on the SL-RSRP and the SL-reference signal power;

setting a sidelink transmission power level for the PSCCH or the PSSCH between the UE and the other UE based on the sidelink path loss; and

causing a signal to be transmitted from the UE to the other UE based on the MCS and the side link transmission power level.

13. An apparatus for a user equipment, UE, to communicate with another UE device-to-device, D2D, in a mobile communications network, comprising:

means for measuring a sidelink received signal strength indication, S-RSSI, and a sidelink interference signal strength indication, S-ISSI;

means for measuring a side link reference signal received power, SL-RSRP, on a physical side link control channel, PSCCH, or a physical side link shared channel, PSSCH, between the UE and the other UE;

means for determining a physical sidelink shared channel reference signal received quality, S-RSRQ, based on the S-RSSI, the S-ISSI, and the SL-RSRP;

means for setting a sidelink transmission Modulation and Coding Scheme (MCS) for the PSCCH or the PSSCH between the UE and the other UE based on the S-RSRQ;

means for determining a side link reference signal power, SL-reference signal power, based on the received indication;

means for determining a sidelink path loss between the UE and the other UE associated with the PSCCH or the PSSCH, respectively, based on the SL-RSRP and the SL-reference signal power;

means for setting a sidelink transmission power level for the PSCCH or the PSSCH between the UE and the other UE based on the sidelink path loss; and

means for causing a signal to be transmitted from the UE to the other UE based on the MCS and the side link transmission power level.

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