Vehicle, Infrastructure, Transceiver, Apparatus, Method and Computer Program for Determining a Physical Layer Configuration for a Radio Link

Embodiments of the present disclosure relate to a vehicle, infrastructure, a transceiver, an apparatus, a method, and a computer program for determining a physical layer configuration for a radio link for a communication system, more particularly, but not exclusively, to a concept for more efficiently determining a physical layer configuration using environmental and state of movement information of a transceiver in a mobile communication system.

Physical layer configurations of modern mobile communication system become more and more adaptable. In order to adapt to the vastly changing radio environment more and more parameters can be adjusted to achieve high spectral efficiency. Most of the mobile communication systems use reference signaling to enable channel estimation, which forms a basis for parameter adjustments such as modulation and coding configurations.

Document US2020/0007247 A1 describes a concept in which a first apparatus communicates with a second apparatus, including transmitting or receiving a first transmission. The first apparatus receives information about the second apparatus from a sensor at the first apparatus and/or from a BSM (basic safety message). The apparatus determines whether the first apparatus and the second apparatus are in a LOS (line-of-sight) condition based on a correlation of the information with one or more of a channel estimation, PMI (precoder matrix index) feedback, or Rl (rank indicator) feedback. The apparatus may adapt a transmission parameter for a second transmission based on a predicted location of the first apparatus or the second apparatus.

Document US 2016/0080961 A1 relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A filter bank-based channel state report and resource allocation method and an apparatus for use in a wireless communication system are provided. The channel state report method of a receiver in a filter bank-based wireless communication system includes receiving filter bank information on at least two filter banks from a transmitter, measuring a channel state of each of at least two filter banks based on the filter bank information, and transmitting channel state information, which is generated based on the measurement result, to the transmitter.

Document EP 3611 891 A1 relates to a signal processing apparatus and method that can reduce deterioration in reception sensitivity. A received signal is corrected using channel information obtained from a plurality of frequency samples being significant components that are extracted from frequency samples of known information included in the received signal. The concept can be applied to, for example, a signal processing apparatus, a transmission device, a reception device, a transceiver device, a communication device, an information processing apparatus, an electronic apparatus, a computer, a program, a storage medium, a system, and the like.

Document EP 3579465 A1 provides a method for determining a modulation and coding scheme (MCS) to be applied to data in a wireless communication system, and a device therefor. Specifically, the method may comprise the steps of: reporting, to a base station, channel state information including a first measurement value related to a channel state between a terminal and a base station; receiving at least one downlink reference signal from the base station; calculating a second measurement value related to the channel state by using the received at least one downlink reference signal; when the second measurement value is equal to or smaller than a preconfigured threshold value in comparison with the first measurement value, transmitting, to the base station, a specific uplink signal requesting a change of an MCS designated to downlink data; and receiving the downlink data, to which the changed MCS has been applied, from the base station.

Document WO 2019/192684 A1 discloses a technique for radio transmitting data. As to a method aspect of the technique data to be transmitted to a receiver is represented by at least two partial modulation symbols. Each of the at least two partial modulation symbols is associated to a different layer of the radio transmission to the receiver. A modulation symbol is generated by combining the at least two partial modulation symbols at different power levels according to the associated layer. The modulation symbol is transmitted to the receiver.

Document US 2019/0319868 A1 discusses various systems and methods for determining and communicating Link Performance Predictions (LPPs), such as in connection with management of radio communication links. The LPPs are predictions of future network behaviors/metrics (e.g. bandwidth, latency, capacity, coverage holes, etc.). The LPPs are communicated to applications and/or network infrastructure, which allows the applications/infrastructure to make operational decisions for improved signaling/link resource utilization. In embodiments, the link performance analysis is divided into multiple layers that determine their own link performance metrics, which are then fused together to make an LPP. Each layer runs different algorithms, and provides respective results to an LPP layer/engine that fuses the results to obtain an LPP.

Document EP 3525374 A1 reveals a method comprising the steps of observing the surroundings of a transmitting participant and determining the position and motion of the communication participants. Further, the method comprises estimating transmission conditions at a later point in time and classify the data for data communication in different categories. Said categories determining susceptibility of said data to transmission errors.

INTERDIGITAL INC: "On NR Uu enhancement for advanced V2X use cases", 3GPP DRAFT; R1-1902602, 16 February 2019, XP051600295 contribution discusses views on the NR Uu for advanced V2X use cases. It is discussed to support NR V2X advanced use cases, UE reports more details (e. g., the range) of message size of Uu V2X periodic traflic to gNB. Further, it is discussed to handle dynamic change of Doppler frequency and support faster handover, UE reports speed and moving direction information to gNB.

Document KR 2011 0071793 A reveals an adaptive modulation and a coding method which is suitable for wireless transfer environment. The adaptive modulation and coding operating apparatus applies active AMC (Active Adaptive Modulation and Coding) technique or manual AMC (Passive Adaptive Modulation and Coding) technique to data information transmitted and received in the communications between the communications between the vehicle and the road side unit.

Document US 2017/041760 A1 reveals a method for adapting at least one parameter of a communication system between two subscribers, wherein at least one subscriber is mobile. In this case a current position of the mobile subscriber is determined at a time and a channel quality for a future time is estimated on the basis of the current position using an environmental model.

Document US 2017/295596 A1 reveals a base station, which may differentiate, determine, configure, employ and/or allocate a first physical random access channel (PRACH) resource set and a second PRACH resource set. The first PRACH resource set to be used by user equipments (UEs) experiencing a higher Doppler condition than UEs using the second PRACH resource set. The base station may transmit an indication of the first PRACH resource set and the second PRACH resource set to the UE.

There is a demand for an improved physical layer adaptation/configuration concept in a mobile communication system.

This demand is accommodated by the subject-matter of the independent claims.

Embodiments are based on the finding, that conventional link adaptation methods mostly utilize a Signal-to-Noise Ratio (SNR) knowledge for selection of the most appropriate modulation and coding scheme (MCS). In some situations, the adaptation of modulation and coding schemes based purely on such metrics can lead to inadequate actions, e.g. decreasing the modulation order instead of increasing a density of channel estimation pilots. Embodiments are based on the finding that not only the MCS can be adapted but a more complete set of physical layer parameters. Moreover, an initial parameter set is chosen based on the knowledge of actual parameters of the environment and a state of movement of a transceiver.

Embodiments provide a method for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link. The method comprises obtaining information related to an environment and a state of movement of the first and second transceivers. The method comprises estimating a radio condition of the radio link based on the information related to the environment and the state of movement of the first and second transceivers. The method further comprises determining the physical layer configuration for the radio link based on the radio condition. Considering a state of movement of the transceivers and environmental information a more appropriate and efficient estimation of a radio condition of a radio link may be enabled and therewith a more appropriate choice of a physical layer configuration.

For example, the obtaining of the information related to the environment and the state of movement of the first and second transceivers comprises evaluating sensor data of the first transceiver. Sensor data available at a transceiver may provide a basis for determining environmental data and information on the state of movement of the transceiver. Sensor data may be available at the transceiver and may therefore form an efficient basis for radio condition estimation as it does not need be communicated using valuable air interface resources. In some embodiments the obtaining of the information related to the environment and the state of movement of the first and second transceivers comprises evaluating an environmental model of the first transceiver. A transceiver may model its environment using sensor or other data available. In the environmental model there may be static and dynamic objects, which also affect the radio environment. Embodiments may improve the estimation of the radio condition by taking the environmental model into account, e.g. with respect to moving reflectors in the environment.

The information related to the environment and the state of movement of the first and second transceivers may comprise an environmental map of the first transceiver. The environmental map may further contribute to a better understanding of the radio environment, which may further improve estimation of the radio condition.

Moreover, at least in some embodiments the obtaining of the information related to the environment and the state of movement of the first and second transceivers may comprise receiving broadcast messages from traffic participants. Such messages may be communicated on a regular basis, e.g. cyclically or periodically, among traffic participants. The knowledge about a status, e.g. location, speed, travel direction, of traffic participants may contribute to a better knowledge of the environment condition and may therefore enable improved estimation of the radio condition.

The information related to the environment and the state of movement of the first and second transceivers may comprises at least one element of the group of positions of the first and second transceivers, a relative speed between the first and second transceivers, a mutual distance of the first and second transceivers, and distances of other transceivers and/or other physical objects. The more detailed the information on the state of movement and the environment the better the radio condition estimation.

For example, the estimating of the radio condition comprises estimating a Doppler shift based on a relative movement between the first and the second transceivers. The Doppler shift may relate to a density configuration of reference symbols for the physical layer configuration in an embodiment.

The physical layer configuration may comprise at least one element of the group of a subcarrier spacing, a pilot symbol configuration in time and/or frequency, a time slot duration, a modulation order, and coding parameters. In embodiments, a physical layer configuration may be highly adaptive and a variety of physical layer parameters may be set.

The physical layer configuration may be an initial physical layer configuration and the method may further comprise fine tuning the physical layer configuration during communication on the radio link. In line with the above, an initial physical layer configuration may be better adapted to the real radio conditions through consideration of environmental information and a state of movement of the first and/or second transceivers.

The physical layer configuration may be a random access configuration. Radio transmission may be more efficient as embodiments may enable to adapt a physical layer configuration for random access in a better way to the actual radio conditions.

In embodiments the first transceiver may be a vehicle and the second transceiver may be a vehicle or infrastructure of a mobile communication system. Embodiments may exploit the environmental information available at a vehicle.

Embodiments further provide a computer program having a program code for performing one or more of the above described methods, when the computer program is executed on a computer, processor, or programmable hardware component. A further embodiment is a computer readable storage medium storing instructions which, when executed by a computer, processor, or programmable hardware component, cause the computer to implement one of the methods described herein.

Another embodiment is an apparatus for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link. The apparatus comprises a transmitter module for communicating with the second transceiver and a control module configured to control the transmitter module, and to perform one of methods described herein. Another embodiment is a vehicle comprising the apparatus. A further embodiment is infrastructure of a mobile communication system, e.g. a base station, an access point or a NodeB, comprising the apparatus.

Some other features or aspects will be described using the following non-limiting embodiments of apparatuses or methods or computer programs or computer program products by way of example only, and with reference to the accompanying figures, in which: Fig. 1 illustrates a block diagram of an embodiment of a method for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link;

Fig. 2 illustrates a block diagram of an embodiment of an apparatus for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver and an embodiment of a vehicle or infrastructure;

Fig. 3 illustrates a block diagram of flow chart of a method for selecting a modulation and coding scheme in an embodiment; and

Fig. 4 shows a flowchart of a method for selecting a physical layer configuration in an embodiment.

Various example embodiments will now be described more fully with reference to the accompanying drawings in which some example embodiments are illustrated. In the figures, the thicknesses of lines, layers or regions may be exaggerated for clarity. Optional components may be illustrated using broken, dashed or dotted lines.

Accordingly, while example embodiments are capable of various modifications and alternative forms, embodiments thereof are shown by way of example in the figures and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed, but on the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. Like numbers refer to like or similar elements throughout the description of the figures.

As used herein, the term "or" refers to a non-exclusive or, unless otherwise indicated (e.g., “or else” or “or in the alternative”). Furthermore, as used herein, words used to describe a relationship between elements should be broadly construed to include a direct relationship or the presence of intervening elements unless otherwise indicated. For example, when an element is referred to as being “connected” or “coupled” to another element, the element may be directly connected or coupled to the other element or intervening elements may be present.

In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Similarly, words such as “between”, “adjacent”, and the like should be interpreted in a like fashion. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes” or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 illustrates a block diagram of a flowchart of a method 10 for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link. The method 10 comprises obtaining 12 information related to an environment and a state of movement of the first and second transceivers and estimating 14 a radio condition of the radio link based on the information related to the environment and the state of movement of the first and second transceivers. The method further comprises determining 16 the physical layer configuration for the radio link based on the radio condition.

Fig. 2 illustrates a block diagram of an embodiment of an apparatus 20 for determining a physical layer configuration for a radio link at a first transceiver 100 to communicate with a second transceiver 200. The apparatus 20 comprises a transmitter module 22 for communicating with the second transceiver 200 and a control module 24, which is coupled with the transmitter module 22. The control module 24 is configured to control the transmitter module 22 and to perform the method 10 as described herein. Fig. 2 further illustrates an embodiment of the first transmitter 100 comprising an embodiment of the apparatus 20. Further embodiments are a vehicle or infrastructure of a mobile communication system comprising the first transceiver 100. The second transceiver 200 may as well comprise an embodiment of the apparatus 20. Fig. 2 also illustrates an embodiment of a communication system 300 with the first and second transceivers 100, 200. The transmitter module 22 may also comprise receiver features and may hence be a transceiver module. It may be implemented as any means for transmitting, receiving or transceiving, i.e. receiving and/or transmitting etc., one or more transmitter/receiver units, one or more transmitter/receiver devices and it may comprise typical receiver and/or transmitter components, such as one or more elements of the group of one or more Low-Noise Amplifiers (LNAs), one or more Power Amplifiers (PAs), one or more filters or filter circuitry, one or more diplexers, one or more duplexers, one or more Analog-to-Digital converters (A/D), one or more Digital-to-Analog converters (D/A), one or more modulators or demodulators, one or more mixers, one or more antennas, etc. In some embodiments, the control module 24 may provide some functionality that may be found in transceiver modules. For example, the control module 24 may be a processing module of the transmitter/receiver/transceiver module 22 and may comprise one or more filters or filter circuitry and/or one or more modulators or demodulators.

In embodiments the control or processing/control module 24 may be implemented using one or more processing units, one or more processing devices, any means for processing, such as a processor, a computer or a programmable hardware component being operable with accordingly adapted software. In other words, the described function of the processing or control module 24 may as well be implemented in software, which is then executed on one or more programmable hardware components. Such hardware components may comprise a general-purpose processor, a Digital Signal Processor (DSP), a micro-controller, etc. The respective processing or control module 24 may be configured to carry out any of the methods described herein.

The first and second transceivers 100, 200 may be any devices of a wireless communication system 300, e.g. a mobile communication system, a broadcast system, a unicast system etc.

The mobile communication system 300 may, for example, be an Orthogonal Time Frequency Space (OTFS) system or one of the Third Generation Partnership Project (3GPP)-standardized mobile communication networks, where the term mobile communication system is used synonymously to mobile communication network. The mobile or wireless communication system may correspond to a mobile communication system of the 5th Generation (5G) and may use mm-Wave technology. The mobile communication system may correspond to or comprise, for example, a Long-Term Evolution (LTE), an LTE-Advanced (LTE-A), High Speed Packet Access (HSPA), a Universal Mobile Telecommunication System (UMTS) or a UMTS Terrestrial Radio Access Network (UTRAN), an evolved-UTRAN (e-UTRAN), a Global System for Mobile communication (GSM) or Enhanced Data rates for GSM Evolution (EDGE) network, a GSM/EDGE Radio Access Network (GERAN), or mobile communication networks with different standards, for example, a Worldwide Inter-operability for Microwave Access (WIMAX) network IEEE 802.16 or Wireless Local Area Network (WLAN) IEEE 802.11, generally an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Time Division Multiple Access (TDMA) network, a Code Division Multiple Access (CDMA) network, a Wideband-CDMA (WCDMA) network, a Frequency Division Multiple Access (FDMA) network, a Spatial Division Multiple Access (SDMA) network, etc.

A base station transceiver or infrastructure can be operable or configured to communicate with one or more active mobile transceivers and a base station transceiver can be located in or adjacent to a coverage area of another base station transceiver, e.g. a macro cell base station transceiver or small cell base station transceiver. Hence, embodiments may provide a mobile communication system 300 comprising two or more mobile transceivers and one or more base station transceivers, wherein the base station transceivers may establish macro cells or small cells, as e.g. pico-, metro-, or femto cells. A mobile transceiver may correspond to a smartphone, a cell phone, user equipment, a laptop, a notebook, a personal computer, a Personal Digital Assistant (PDA), a Universal Serial Bus (USB) -stick, a car, a vehicle etc. A mobile transceiver may also be referred to as User Equipment (UE) or mobile in line with the 3GPP terminology. A vehicle may correspond to any conceivable means for transportation, e.g. a car, a bike, a motorbike, a van, a truck, a bus, a ship, a boat, a plane, a train, a tram, etc.

A base station transceiver can be located in the fixed or stationary part of the network or system. A base station transceiver may correspond to a remote radio head, a transmission point, an access point, a macro cell, a small cell, a micro cell, a femto cell, a metro cell etc. A base station transceiver can be a wireless interface of a wired network, which enables transmission of radio signals to a UE or mobile transceiver. Such a radio signal may comply with radio signals as, for example, standardized by 3GPP or, generally, in line with one or more of the above listed systems. Thus, a base station transceiver may correspond to a NodeB, an eNodeB, a Base Transceiver Station (BTS), an access point, a remote radio head, a relay station, a transmission point etc., which may be further subdivided in a remote unit and a central unit.

A mobile transceiver can be associated with a base station transceiver or cell. The term cell refers to a coverage area of radio services provided by a base station transceiver, e.g. a NodeB (NB), an eNodeB (eNB), a remote radio head, a transmission point, etc. A base station transceiver may operate one or more cells on one or more frequency layers, in some embodiments a cell may correspond to a sector. For example, sectors can be achieved using sector antennas, which provide a characteristic for covering an angular section around a remote unit or base station transceiver. In some embodiments, a base station transceiver may, for example, operate three or six cells covering sectors of 120° (in case of three cells), 60° (in case of six cells) respectively. A base station transceiver may operate multiple sectorized antennas.

In the following a cell may represent an according base station transceiver generating the cell or, likewise, a base station transceiver may represent a cell the base station transceiver generates.

Mobile transceivers may communicate directly with each other, i.e. without involving any base station transceiver, which is also referred to as Device-to-Device (D2D) communication. An example of D2D is direct communication between vehicles, also referred to as Vehicle-to- Vehicle communication (V2V). In order to do so radio resources are used, e.g. frequency, time, code, and/or spatial resources, which may as well be used for wireless communication with a base station transceiver. The assignment of the radio resources may be controlled by the base station transceiver, i.e. the determination which resources are used for D2D and which are not. Here and in the following radio resources of the respective components may correspond to any radio resources conceivable on radio carriers and they may use the same or different granularities on the respective carriers. The radio resources may correspond to a Resource Block (RB as in LTE/LTE-A/LTE-unlicensed (LTE-U)), one or more carriers, sub-carriers, one or more radio frames, radio sub-frames, radio slots, one or more code sequences potentially with a respective spreading factor, one or more spatial resources, such as spatial sub-channels, spatial precoding vectors, any combination thereof, etc.

For example, direct Cellular Vehicle-to-Anything (C-V2X), where V2X includes at least V2V, V2- Infrastructure (V2I), etc., transmission according to 3GPP Release 14 can be managed by infrastructure (so-called mode 3) or run in a User Equipment (UE) Autonomous mode (UEA), (so-called mode 4). In embodiments mobile transceivers may be registered in the same mobile communication system 300. In other embodiments one or more of the two or more mobile transceivers may be registered in different mobile communication systems 300. The different mobile communication systems 300 may use the same access technology but different operators or they may use different access technologies as outlined above.

In embodiments the physical layer configuration may comprise any parameters which can be configured in respect of the physical layer. The physical layer configuration may comprise at least one element of the group of a subcarrier spacing, a pilot symbol configuration in time and/or frequency, a time slot duration, a modulation order, and coding parameters. A physical layer configuration may comprise parameters that influence or set one or more elements of the group of a time division duplex scheme, a frequency division duplex scheme, a code division duplex scheme, a spatial division duplex scheme, and an orthogonal frequency division multiplexing scheme. The physical layer configuration may comprise at least an orthogonal frequency division multiplexing component. For example, the physical layer data channel configuration may comprise information on a subcarrier bandwidth configuration for the orthogonal frequency division multiplexing component. Such a configuration may involve the indication or configuration of further parameters, for example, symbol duration, cyclic prefix duration, time transmission interval (TTI) length, subcarrier spacing, etc. The physical layer data channel configuration may comprise information on a numerology defined for the mobile communication system.

Information related to an environment may be an environmental model, which is a digital model of the environment of the first transceiver, which can be based on sensor data or on exchanged messages with other transceivers. For example, the first transceiver may be a vehicle, which can be equipped with multiple sensors, such as visual/optical (camera), radar, ultrasonic, lidar (light detection and ranging), etc. A vehicle may model its surroundings using this sensor data. At least in some embodiments such a model may be based on known static data, e.g. as map data comprising a course of one or more roads, intersections, traffic infrastructure (lights, signs, crossings, etc.), buildings, etc. Such a basic layer for the environmental model may be complemented by dynamic or moving objects detected through sensor data. Such a sensor data-based environmental model may form the basis for the second environmental map.

An environmental map may comprise static and dynamic objects in the environment of the vehicle/traffic entity along at least a part of the vehicle’s trajectory. Such a part of the trajectory may be, for example, the part the vehicle is planning to travel in the next 30s, 1 minute, 5 minutes, 10 minutes, etc. A dynamic object is one that is not permanently static/fixed such as other road participants, pedestrians, vehicles, but also semi-static objects such as components of a moving construction side, traffic signs for road or lane narrowing, etc. For example, such dynamic objects may be other vehicles, pedestrians, bicycles, road participants, etc. When determining the environmental model not all objects in the model may be determined with the same confidence. There are objects for which a higher certainty can be achieved than for others. For example, if multiple sensors can identify or confirm a certain object its presence and/or state of movement can potentially be determined with a higher confidence compared to a case in which only data from a single sensor is indicative of an object. Similar considerations apply with respect to a message-based map. If there is an object in the environment multiple traffic participants report on, a higher confidence results as compared to the case in which only a single road participant reports on the object.

In the following an embodiment will be described, which enables a 5G NR physical layer adaptation.

After a cold start of a cellular network user equipment (UE), when the equipment has no knowledge on its environment, its physical layer parameters may be adjusted according to estimated link quality variables such as bit-to error ratio (BER), data throughput or signal-to- noise ratio (SNR). Those link quality parameters can be derived from an initial handshaking transmission that requires measurement time duration, which may be reduced in embodiments. When the derived parameters (SNR, BER etc.) are not within an appropriate range (due to sharp transitions of coded BER curves), this handshaking transmission may be repeated with other modulation and coding scheme parameters. This process may result in an iterative mechanism ending up with a set of parameters, which will ensure quasi error free transmission with the lowest possible redundancy and robustness. More iterations of the above-mentioned action lead to a higher probability of achieving an appropriate set of modulation and coding parameters, however, generate increasing latency together with reduction of the achievable data throughput. In embodiments the number of iterations may be reduced. In some embodiments the iteration may even be avoided.

Moreover, monitoring of the link quality metrics, i.e. , BER, SNR and/or throughput does not provide full information about the reason why the link quality is eventually degraded. Low link quality may be caused by a variety of effects - from multipath propagation or high relative movement between transmitter and receiver to outdated channel state information (CSI) or even adjacent channel emissions. In some situations, the adaptation of modulation and coding schemes based purely on such metrics can lead to inadequate actions, e.g. decreasing the modulation order instead of increasing of density of channel estimation pilots.

Considering the concept of vehicular communication, the communication links between an ego- vehicle and a base station (BS) and/or vehicles in the relevant surrounding are going to exhibit a Doppler frequency shift, which is determined before the actual transmission of the built-in user equipment begins. Such frequency shift is relatively easy to compensate in the pure line-of-sight links, but its full compensation in the presence of multipath propagation is still challenging task. The estimating 14 of the radio condition may comprise estimating a Doppler shift based on a relative movement between the first and the second transceivers.

Embodiments may provide a benefit of acquiring optimal or improved physical layer settings when the cellular user equipment is integrated to an electronic system of a vehicle. The first transceiver may be a vehicle and the second transceiver may be a vehicle or infrastructure of a mobile communication system 300. As such, the vehicle is considered to have at its disposal a knowledge of its position and relevant surroundings. This knowledge is obtained from active or passive sensors such as built-in radars, cameras, lidars, high-accuracy positioning system and high definition maps (HD maps). In the method 10 the obtaining 12 of the information related to the environment and the state of movement of the first and second transceivers may comprise evaluating sensor data of the first transceiver. For example, the obtaining 12 of the information related to the environment and the state of movement of the first and second transceivers comprises evaluating an environmental model of the first transceiver. Furthermore, at least in some embodiments the obtaining 12 of the information related to the environment and the state of movement of the first and second transceivers may comprise receiving broadcast messages from traffic participants.

In some embodiments the information related to the environment and the state of movement of the first and second transceivers comprises an environmental map of the first transceiver. It may include

(1) positions of other vehicles and/or BS,

(2) their speed relative to the ego-vehicle, and

(3) mutual distances of the vehicles and distances between vehicles and other physical objects.

For example, in embodiments the information related to the environment and the state of movement of the first and second transceivers comprises at least one element of the group of positions of the first and second transceivers, a relative speed between the first and second transceivers, a mutual distance of the first and second transceivers, and distances of other transceivers and/or other physical objects.

Because the BER and SNR strongly correlates with Doppler shifts and distances respectively, embodiments may adapt the physical layer parameters from the mentioned quantities, i.e. :

(1) positions of other vehicles, (2) their speed relative to the ego-vehicle, and

(3) mutual distances of the vehicles and distances between vehicles and other physical objects.

The benefit of at least some embodiments is that the modulation and coding parameters are optimized before the actual transmission and therefore latency is reduced, and data throughput is increased.

The quantities (1)-(3) for optimization/improvement of an itemized set of physical layer link parameters, can be: subcarrier spacing, proportional to maximal expected Doppler shift, density of pilots for channel estimation in time and frequency domain, proportional to maximal expected Doppler shift, time-slot duration, inversely proportional to maximal expected Doppler shift, modulation order, inversely proportional to maximal expected Doppler shift, and forward error correction (FEC) coder parameters (code rate), inversely proportional to maximal expected Doppler shift.

Fig. 3 illustrates a block diagram of flow chart of a method for selecting a modulation and coding scheme in an embodiment. This flowchart shows conventional link estimation, which may be eased using embodiments. The flowchart shows proposed 5G NR physical layer adaptation and it starts in step 31. In step 32 a timer t is set to 1 and a legacy modulation and coding scheme (MCS) parameter is set to MCS _L . In step 33 it is checked whether MCS _L is still valid and if so, transmission is carried out in step 35. If not MCSi is set to MCS _INIT in step 34, which is an initial value and transmission is carried out in step 35. In step 37 BER is evaluated against a threshold. If BER is above the threshold 37 (too many errors) the timer is increased t=t+1 and the next MCSi _+t is set to MCS _t -1 (more robust MCS) in step 36. If BER is below the threshold 37 (more errors affordable) the timer is increased t=t+1 and the next MCSi _+t is set to MCS _t +1 (higher spectral efficiency) in step 38.

More details on conventional link adaptation methods can be found in L. Lihua, Z. Mingyu, X. Yongtai, W. Haifeng and Z. Ping, "LDPC Coded AMC Based on Decoding Iteration Times for OFDM Systems," VTC Spring 2008 - IEEE Vehicular Technology Conference, Singapore, 2008, pp. 1157-1161, doi: 10.1109A/ETECS.2008.245, and M. S. Al-Janabi, C. C. Tsimenidis, B. S. Sharif and S. Y. L. Goff, "Adaptive MCS Selection in OFDM Systems Based on Channel Frequency Coherence," 2009 Fifth Advanced International Conference on Telecommunications, Venice, 2009, pp. 177-182. doi: 10.1109/AICT.2009.37, which describe the principle of the operations depicted in Fig. 3 mostly utilizing signal-to-noise- ratio (SNR) knowledge for selection of the most appropriate modulation and coding scheme (MCS). In order to get this SNR estimate, data transmission needs to occur within the coherence time of the channel. If the value of MCS is outdated, the MCS needs to be set to its initial state 34, for which several strategies may be used, e.g. the lowest MCS to guarantee the correct signal reception. Afterwards, the MCS index is adapted iteratively based on the Bit Error Rate (BER) values.

Fig. 4 shows a flowchart of a method for selecting a physical layer configuration in an embodiment. The method starts in step 41. In step 42 a timer t=1 is set and a legacy parameter set Po is selected. In step 44 it is checked if Po is still valid. If so, transmission is carried out in step 46. If not, another parameter set Pi is chosen from a look-up table (LUT) in step 45. This selection is further based on radar, lidar, onboard camera, GPS and other sensor data determined in step 43 (e.g. further determining velocity, position, relative speeds and distances). In step 46 transmission is then carried out based on Pi. In step 48 BER is evaluated against a threshold. If BER is above the threshold 48 (too many errors) the timer is increased t=t+1 and the next Pi _+t is set to PH (more robust MCS) in step 47. If BER is below the threshold 48 (more errors affordable) the timer is increased t=t+1 and the next Pi _+t is set to Pi+1 (higher spectral efficiency) in step 49.

The embodiment as shown in Fig. 4, not only adapts MCS, but a complete set of physical layer parameters (P) listed above. Moreover, the initial parameter set is chosen based on the knowledge of actual parameters of the environment. The iterative procedure based on BER serves for fine tracking of the PHY parameter set. For example, the physical layer configuration is an initial physical layer configuration and the method 10 further comprises fine tuning 46, 47, 48, 49 the physical layer configuration during communication on the radio link. The physical layer configuration Pi may be a random access configuration.

The aspects and features mentioned and described together with one or more of the previously detailed examples and figures, may as well be combined with one or more of the other examples in order to replace a like feature of the other example or in order to additionally introduce the feature to the other example.

Examples may further be or relate to a computer program having a program code for performing one or more of the above methods, when the computer program is executed on a computer or processor. Steps, operations or processes of various above-described methods may be performed by programmed computers or processors. Examples may also cover program storage devices such as digital data storage media, which are machine, processor or computer readable and encode machine-executable, processor-executable or computer-executable programs of instructions. The instructions perform or cause performing some or all of the acts of the above-described methods. The program storage devices may comprise or be, for instance, digital memories, magnetic storage media such as magnetic disks and magnetic tapes, hard drives, or optically readable digital data storage media. Further examples may also cover computers, processors or control units programmed to perform the acts of the above-described methods or (field) programmable logic arrays ((F)PLAs) or (field) programmable gate arrays ((F)PGAs), programmed to perform the acts of the above-described methods.

The description and drawings merely illustrate the principles of the disclosure. Furthermore, all examples recited herein are principally intended expressly to be only for illustrative purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor(s) to furthering the art. All statements herein reciting principles, aspects, and examples of the disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof.

A functional block denoted as “means for ...” performing a certain function may refer to a circuit that is configured to perform a certain function. Hence, a “means for s.th.” may be implemented as a “means configured to or suited for s.th.”, such as a device or a circuit configured to or suited for the respective task.

Functions of various elements shown in the figures, including any functional blocks labeled as “means”, “means for providing a signal”, “means for generating a signal.”, etc., may be implemented in the form of dedicated hardware, such as “a signal provider”, “a signal processing unit”, “a processor”, “a controller”, etc. as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which or all of which may be shared. However, the term “processor” or “controller” is by far not limited to hardware exclusively capable of executing software, but may include digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC), field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), and non-volatile storage. Other hardware, conventional and/or custom, may also be included.

A block diagram may, for instance, illustrate a high-level circuit diagram implementing the principles of the disclosure. Similarly, a flow chart, a flow diagram, a state transition diagram, a pseudo code, and the like may represent various processes, operations or steps, which may, for instance, be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown. Methods disclosed in the specification or in the claims may be implemented by a device having means for performing each of the respective acts of these methods.

It is to be understood that the disclosure of multiple acts, processes, operations, steps or functions disclosed in the specification or claims may not be construed as to be within the specific order, unless explicitly or implicitly stated otherwise, for instance for technical reasons. Therefore, the disclosure of multiple acts or functions will not limit these to a particular order unless such acts or functions are not interchangeable for technical reasons. Furthermore, in some examples a single act, function, process, operation or step may include or may be broken into multiple sub-acts, -functions, -processes, -operations or -steps, respectively. Such sub acts may be included and part of the disclosure of this single act unless explicitly excluded.

Furthermore, the following claims are hereby incorporated into the detailed description, where each claim may stand on its own as a separate example. While each claim may stand on its own as a separate example, it is to be noted that - although a dependent claim may refer in the claims to a specific combination with one or more other claims - other examples may also include a combination of the dependent claim with the subject matter of each other dependent or independent claim. Such combinations are explicitly proposed herein unless it is stated that a specific combination is not intended. Furthermore, it is intended to include also features of a claim to any other independent claim even if this claim is not directly made dependent to the independent claim. List of reference signs

Method for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link obtaining information related to an environment and a state of movement of the first and second transceivers estimating a radio condition of the radio link based on the information related to the environment and the state of movement of the first and second transceivers determining the physical layer configuration for the radio link based on the radio condition apparatus for determining a physical layer configuration for a radio link at a first transceiver to communicate with a second transceiver via the radio link transmitter module control module

Start legacy setting is setting valid? initial setting transmission MCS decrease BER< threshold MCS increase Start legacy setting sensor data is setting valid?

Pi choosen from LUT transmission MCS decrease BER< threshold MCS increase first transceiver second transceiver communication system