Channel state information

Abstract

Methods, apparatus and systems for channel state information determination and reporting are disclosed.

Description

[0001] Channel state information

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure is related to but not limited to communication networks as defined by the 3GPP standard, such as the 5G and / or 6G standard. The disclosure in particular relates to channel state information.

[0004] BACKGROUND

[0005] For data transmissions performed in a mobile network (e.g., uplink from a mobile device to a network node, or downlink from a network node to a mobile device) different transmission conditions may be present, e.g., signal strength, signal to noise and interference ratio and / or combinations thereof. Such conditions may affect quality of a given radio link (e.g., between a terminal device and a network node). An accurate prediction of such conditions may be difficult and instead, measurements may be conducted. An indication of a quality of the respective radio link may need to be determined (e.g., through measurement) and / or reported (e.g., by a receiving entity, e.g., by the terminal device), for instance in order to be able to adjust at least one transmission parameter to the conditions.

[0006] SUMMARY OF SOME EXEMPLARY EMBODIMENTS

[0007] In wireless communication networks, so called Channel State Information, CSI, may be determined, e.g., for a given radio link. The CSI may for instance be determined (e.g., computed) based on a reference signal, e.g., received by a receiving entity such as a terminal device and / or transmitted by a transmitting entity such as for instance a network node. The reference signal may thus travel across a radio link to be measured. The reference signal may have a particular type and / or a particular bandwidth across which it is transmitted.

[0008] A reference signal may for instance be intended and / or configured for use in a channel state information determination procedure. A reference signal may for instance comprise at least one of a Zero Power, ZP, Channel State Information Reference Signal, CSI-RS, and / or Non-Zero Power, NZP, CSI-RS.

[0009] In modern communication networks, further (e.g., different from the above-listed) reference signals may be used, for instance for various individual purposes. For instance, such reference signals may be intended for, fulfil and / or be configured for purposes such as demodulation, phase tracking, synchronization, and / or combinations thereof. Reference signals may for instance comprise a Primary Synchronization Signal, PSS, a Secondary Synchronization Signal, SSS, a Synchronization Signal Block, SSB, signal, a Demodulation Reference Signal, DMRS (e.g., for a specific channel such as Physical Broadcast CHannel, PBCH, Physical Downlink Control CHannel, PDCCH, Physical Downlink Shared CHannel, PDSCH), a Phase Tracking Reference Signal, PTRS, and / or a Sounding Reference Signal, SRS.

[0010] It has been recognized that reference signals (e.g., which may be intended primarily and / or at least partially for non-CSI-related purposes), in particular reference signals other than CSI-RS, may carry and / or provide (e.g., additional) information about radio link quality, e.g., about CSI. Such reference signals are currently not being used in CSI feedback computation. It has thus been recognized that such reference signals may be harnessed in order to provide alternative, particularly refined, particularly efficient (e.g., using little radio resources) and / or particularly early CSI estimations and / or reports. It is thus inter alia one of the objects of the disclosed subject matter to provide improved approaches for channel state information determination and / or provision (e.g., reporting).

[0011] According to a first example aspect, a method is proposed (e.g., performed and / or controlled by a mobile device, user equipment (UE)), comprising, by a terminal device: receiving a first reference signal (e.g., Demodulation Reference Signal, DMRS) of a broadcast channel transmitted by a network node over a first bandwidth (e.g., PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session)(e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way), determining channel state information (e.g., a reference signal strength; a (e.g., differential) quality metric, e.g., of a channel, a CQI of a future channel (e.g., PDSCH, PUSCH))(e.g., indicative of at least one physical property and / or characteristic of a (e.g., DL) radio channel (CQI, RSRP, RSRQ, SNIR, path loss, spatial / MI MO properties) at least partially based on the received first reference signal, providing (e.g., reporting and / or transmitting) the determined channel state information to the network node.

[0012] According to a second example aspect, a method is proposed (e.g., performed and / or controlled by a mobile device, user equipment (UE)), comprising, by a terminal device: receiving a first reference signal (e.g., Demodulation Reference Signal, DMRS) transmitted by a network node over a first bandwidth (e.g., PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session)(e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way), receiving a second reference signal transmitted by the network node (e.g., after the transmitting and / or receiving of the first reference signal) over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal, determining a channel quality indication (e.g., to be used for radio link adaption) at least partially based on the received first reference signal and the received second reference signal, and providing (e.g., reporting and / or transmitting) the determined channel quality indication to the network node.

[0013] The method according to the first and / or second example aspect may for instance be performed and / or controlled by an apparatus, for instance a server. Alternatively, the method may be performed and / or controlled by more than one apparatus, for instance a server cloud comprising at least two servers. Alternatively, the method may for instance be performed and / or controlled by an electronic device, e.g. a node in a communication system and / or by a terminal device, e.g., a user equipment (UE). For instance, the method may be performed and / or controlled by using at least one processor of the electronic device.

[0014] According to a further example aspect, a computer program is disclosed, the computer program when executed by a processor causing an apparatus, for instance a server, a network node or a terminal device, e.g., a UE, to perform and / or control the actions of the method according to the first and / or second example aspect.

[0015] The computer program may be stored on computer-readable storage medium, in particular a tangible and / or non-transitory medium. The computer readable storage medium could for example be a disk or a memory or the like. The computer program could be stored in the computer readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer readable storage medium may be intended for taking part in the operation of a device, like an internal or external memory, for instance a Read-(e.g., Only) Memory (ROM) or hard disk of a computer, or be intended for distribution of the program, like an optical disc.

[0016] According to a further example aspect, an apparatus is disclosed, configured to perform and / or control or comprising respective means for performing and / or controlling the method according to the first and / or second example aspect.

[0017] The means of the apparatus can be implemented in hardware and / or software. They may comprise for instance at least one processor for executing computer program code for performing the required functions, at least one memory storing the program code, or both. Alternatively, they could comprise for instance circuitry that is designed to implement the required functions, for instance implemented in a chipset or a chip, like an integrated circuit. In general, the means may comprise for instance one or more processing means or processors.

[0018] The above-disclosed apparatus according to any aspect may be a module or a component for a device, for example a chip. Alternatively, the disclosed apparatus according to any aspect may be a device, for instance a server or server cloud. The disclosed apparatus according to any aspect may comprise (e.g., only) the disclosed components, for instance means, processor, memory, or may further comprise one or more additional components.

[0019] A terminal device, e.g., a user equipment (UE) may for instance correspond to a mobile device such as for example a mobile phone, tablet, smartwatch, a laptop, a Personal Digital Assistant (PDA) device, a wearable, an Internet-of-Things (IOT) device, an HOT (Industrial IOT) device, a vehicle and / or combinations thereof. Such a user equipment may also be referred to as user device.

[0020] A network node may correspond to a component of a communication network such as for instance a Base Transceiver Station (BTS), a nodeB, an evolved node B (eNB), a Next Generation NodeB (gNB), a distributed unit (DU), a central unit (CU) and / or combinations thereof.

[0021] The method according to the first example aspect comprises receiving a first reference signal. The first reference signal may for instance comprise and / or correspond to a Demodulation Reference Signal, DMRS The first reference signal is a reference signal of a broadcast channel. The first reference signal may thus be unspecific to a UE and / or be transmitted to multiple UEs. The broadcast channel may for instance correspond to a Physical broadcast channel, PBCH. The DMRS may thus, as the first reference signal, be specific to the PBCH. The first reference signal is transmitted by a network node. For instance, the first reference signal may be obtained by the terminal device before a communication session is established between the terminal device and the network node. For instance, the first reference signal may be obtained in an unsynchronized mode (e.g., of the terminal device), e.g., before performing (e.g., before the terminal device performs) a random access procedure with the network node. For instance, the first reference signal may be obtained without an (e.g., started) RRC session (e.g., between the terminal device and the network node). The first reference signal is transmitted and / or obtained over a first bandwidth.

[0022] For instance, the first bandwidth may correspond to a bandwidth of a channel via which the first reference signal is transmitted. A bandwidth (e.g., an in particular the first bandwidth) may be characterized by a part of the frequency spectrum, e.g., here, a part of the frequency spectrum used for the transmission of the first reference signal. The (e.g., first) bandwidth may be characterized by a particular subband and / or a subset of subbands used for transmission of a particular (e.g., the first) reference signal.

[0023] The method according to the first example aspect further comprises determining channel state information, CSI. CSI may for instance comprise and / or correspond to a reference signal strength, e.g., a received signal strength (e.g., measured by the terminal device) of the first reference signal. A signal strength may for instance be quantified as a Reference Signal Receive Power, RSRP, a Received Signal Strength Indicator, RSSI, a Signal to Noise Ratio (SNR), a Signal to Noise plus Interference Ratio, SNIR, and / or combinations thereof.

[0024] The CSI may additionally or alternatively correspond to and / or comprise a quality metric of a radio link and / or of a channel, e.g., of the channel via which the first (e.g., or a further) reference signal is obtained and / or for different channel, e.g., for a data channel, e.g., a future (e.g., to be established) channel, such as for instance a data channel (e.g., uplink and / or downlink; e.g., PDSCH, PUSCH). The CSI may additionally or alternatively correspond to and / or comprise a Channel Quality Indication, CQI, e.g., of (such) a future channel. A CQI may be used (e.g., directly) for radio link adaption of a radio link, e.g., downlink radio link from the network node to the terminal device, e.g., by the network node. The CSI may additionally or alternatively correspond to and / or comprise an Interference and Noise Indication, e.g., and interference and noise measurement performed by the terminal. The CSI may additionally or alternatively correspond to and / or comprise and / or be indicative of at least one physical property and / or at least one characteristic of a (e.g., downlink, DL) radio channel. For instance, the CSI may comprise and / or correspond to and / or be indicative of a Reference Signal Received Power, RSRP, Reference Signal Received Quality, RSRQ, Signal to Noise plus Interference Ratio, SNIR, a path loss, at least one spatial and / or multiple input multiple output, MIMO, property).

[0025] The CSI is determined at least partially based on the received first reference signal. For instance, at least one property of the first reference signal is determined such as for instance a signal strength indication of the first reference signal. The determining may end here and the CSI may be a signal strength of the first reference signal. The determining may, on the other hand, comprise at least one further step and may comprise determining (e.g., computing, estimating, inferring, deriving and / or combinations thereof) other CSI metrics including but not limited to a CSI in a bandwidth outside the first bandwidth (termed oCSI) and / or CQI of a (e.g., future)(e.g., data) channel.

[0026] The method according to the first example aspect further comprises providing the determined channel state information to the network node. The method may thus relate to a reporting method for channel state information. For instance, the providing may correspond to a transmitting of the determined CSI to the network node, for instance by using an uplink opportunity, e.g., wherein the uplink opportunity is at least partially usable and / or used (e.g., by the terminal device) for transmitting at least one further piece of information such as for instance, a response within a random access procedure, a control signaling, e.g., for a channel and / or an acknowledgement of a reception of a downlink signaling. The CSI may for instance be transported on a Physical Uplink Control CHannel, PUCCH and / or multiplexed on a Physical Uplink Shared CHannel, PUSCH. The providing may be performed on a next available uplink opportunity after reception of the first reference signal and / or on later uplink opportunities, for instance on an uplink opportunity available (e.g., first) after the determining of the CSI has been performed.

[0027] One technical effect of the method according to the first example aspect is that a CSI may be determined particularly early. It may in particular become possible to determine a CSI before the terminal device has even connected to the network node. The network node may adjust at least one property of the modulation and / or coding (e.g., by selecting a Modulation and Coding Scheme, MCS, index) used for communication with the terminal device based on the (e.g., early) CSI. Additionally or alternatively, the network node may adjust this (e.g., MCS index) further based on the utilization of the Interference and Noise (laN) information received (e.g., also) as part of an (e.g., early) CSI. Thereby, delays in establishing a fully configured (e.g., taking into account current radio interface conditions) communication session may be avoided and signaling may at the same time be reduced. For instance, additionally or alternatively, using an (e.g., transmitted either way, e.g., irrespective of whether CSI is determined based on the reference signal) broadband channel signal reference signal for CSI estimation may lead to a reduction of required reference signals provided by the network node and thus increase efficiency of the use of radio resources. E.g., a transmission (e.g., an initial transmission after random access) of a CSI-RS may be dispensed.

[0028] The method according to the second example aspect comprises receiving a first reference signal. The first reference signal and the receiving of such may be essentially identical to the first example aspect. The first reference signal may additionally or alternatively, be different from a DMRS signal, for instance a CSI reference signal and / or another reference signal such as for instance PSS, SSS; Synchronization Signal Block, SSB, signal, a Phase Tracking Reference Signal, PTRS, a demodulation signal used for a downlink data channel (e.g., for a PDSCH) and / or a Sounding Reference Signal, SRS.

[0029] The method according to the second example aspect further comprises receiving a second reference signal transmitted by the network node. For instance, the second reference signal is transmitted and / or obtained after the transmitting and / or receiving of the first reference signal. The second reference signal is obtained over a second bandwidth which may be different and / or identical to the first bandwidth.

[0030] The second reference signal is of a different type compared to the first reference signal. According to a further embodiment, the first and second reference signal may be of a same type. A reference signal type may in particular correspond to and / or comprise at least one of a (e.g., ZP and / or NZP) CSI-RS, a DMRS (e.g., for a particular channel, e.g., a broadcast channel (e.g., PBCH), a control channel (e.g., Physical Downlink Control CHannel, PDCCH), and / or a data channel (e.g., a Physical Downlink Shared CHannel), PDSCH), a PSS, a SSS, a SSB, a PTRS, and / or an SRS. The reference signal types of the first and / or second reference signals may also be different in at least one more fine-grained characteristic such as for instance for what channel a demodulation reference signal is intended.

[0031] For instance, when at least two different types of reference signals are transmitted and / or received, an offset may be used to translate from one reference signal type to another. For instance, such an offset may be termed a fudge factor. The fudge factor may be used to scale a CSI and / or CQI determined based on a first reference signal to a CSI and / or CQI determined based on a second (e.g., different) reference signal. Such a fudge factor, or offset, may be used for scaling CSI and / or CQI between the two measurements, e.g., in determination of CSI and / or CQI and / or in reporting. For instance, a table of at least one or more fudge factors may comprise fudge factors, e.g., specific to reference signal types and / or combinations of types of reference signals.

[0032] The method according to the second example aspect comprises determining a channel quality indication, CQI. The CQI may for instance be configured to be used for radio link adaption, e.g., by the network node. The determining is at least partially based on the received first reference signal and on the received second reference signal. The terminal device may thus apply some sort of combined processing of the first and the second reference signal to derive a QCI value in the determining step. The CQI may for instance comprise a CQI applicable to (e.g., informative of a channel quality of a channel transmitted and / or received at least partially inside) a bandwidth outside the first bandwidth and / or outside the second bandwidth. The CQI may for instance be configured to be informative of a channel quality of a (e.g., future, e.g., to be established) channel, such as for instance a data channel, in particular a PDSCH.

[0033] The method according to the second example aspect comprises providing (e.g., reporting and / or transmitting) the determined channel quality indication to the network node. The providing may be done in a way as disclosed with respect to the first example aspect.

[0034] According to an embodiment of the first example aspect, the channel state information comprises and / or corresponds to a channel quality indication. According to an embodiment of the second example aspect, the channel quality indication may be comprised by and / or correspond to channel state information. In the following, disclosure (e.g., regarding to a determining, an obtaining and / or a providing of) channel state information additionally applies to a channel quality indication and vice versa, where applicable.

[0035] According to an embodiment of the first and / or the second example aspect, providing the channel state information (e.g., and / or the channel quality indication) comprises transmitting the channel state information as part of a time-unsynchronized uplink transmission (e.g., an uplink signal transmission before applying a (e.g., correct) timing advance correction to an uplink transmission timing) or as part of a random access, RA, procedure (e.g., as part of MsgA of a 2-steps RA procedure, or as part of Msg1 / PRACH preamble or Msg3 of a 4-steps RA procedure).

[0036] A time-unsynchronized uplink transmission may for instance correspond to a transmission performed before an adjustment of a timing of transmissions performed by the terminal device to a delay between the network node and the terminal device has been performed. For instance, a terminal device may receive a correction factor, e.g., a timing advance, TA, command, from the network node (e.g., in the course of a random access, RA, procedure) at a later stage. The unsynchronized transmission may be performed prior to such reception of TA command.

[0037] The channel state information may be provided as part of a random access, RA, procedure, e.g., in at least one (e.g., uplink) message of an RA procedure. The RA procedure may have 2 steps (2-steps RA procedure) or 4 steps (4-steps RA procedure).

[0038] In a 2-steps RA procedure, the terminal device may first (in an uplink signaling typically referred to as MsgA) transmit an RA preamble and data to the network node. In response, the network node may, in a second message, the downlink message MsgB, provide an RA response. These two message may, in the 2-steps RA procedure, form the RA procedure. The CSI may be transmitted in the first message, MsgA, of a 2-steps RA procedure.

[0039] The CSI may also be provided in at least one uplink opportunity of a 4-steps RA procedure. The 4-steps RA procedure comprises a fist uplink message, Msg1, from the terminal device to the network node, carrying the RA preamble. The network node responds with a second message, the downlink message Msg2, carrying the RA response. Following this second message, a third overall and second uplink message, Msg3, follows, carrying a scheduled transmission. Lastly, a fourth message and second downlink message, Mgs4, is transmitted by the network node to the terminal device for contention resolution. At least one of the two uplink transmissions, i.e., Msg1 (e.g., different CSI / CQI values or ranges are associated with different Physical Random Access CHannel, PRACH, preambles or preamble groups) and / or Msg3 (e.g., as part of a scheduled transmission) of a 4-steps RA procedure may be used for CSI transmission. Using a signaling of the RA procedure in particular has the advantage of an early CSI provision. Additionally, no separate signaling is required and the procedure of onboarding the terminal device at the network node does not need to be complicated by an additional, signaling opportunity.

[0040] According to an embodiment of the first and / or second example aspect, the channel state information comprises channel state information applicable (e.g., and / or valid) outside the first bandwidth.

[0041] The first reference signal is obtained in a first bandwidth and may thus in particular allow a determination of channel state information inside this first bandwidth. For instance, a received signal strength can be determined (e.g., measured, e.g., by a communication interface of the terminal device) within the first bandwidth. It has been recognized that the first reference signal may not only be informative for channel properties inside the first bandwidth in which the first reference signal has been transmitted and / or received. Instead, there may for instance exist a correlation between a channel state in the first bandwidth and the channel state in further bandwidths different from the first bandwidth. Such further bandwidths may in particular be (e.g., directly or by a (e.g., predetermined) frequency distance) neighboring and / or otherwise related bandwidths. It has thus further been recognized that is possible to determine CSI (e.g., not only within the first bandwidth but also) applicable and / or valid outside the first bandwidth. For instance, such determining may be based solely on the first reference signal (e.g., properties of the first reference signal measured by the terminal device) and / or may further be based on further factors such as a location of the terminal device, a previous received reference signal, a time of the day, a weather, a historical relationship between CSI in different bandwidths (e.g., for a given location and / or time and / or independent of location or time). Such CSI applicable (e.g., and / or valid) outside the first bandwidth is herein termed oCSI for brevity, wherein complementary to that, a term iCSI may relate to CSI applicable to (e.g., within) the first bandwidth. Such oCSI may for instance have an associated uncertainty, for instance correlated with a difference in frequency range of a bandwidth for which the oCSI is determined and a frequency range of the first bandwidth. When CSI is disclosed, this may comprise oCSI as well as iCSI. or a combination of iCSI and oCSI. For instance a single CSI may be valid and / or applicable across first and a further bandwidth outside the first bandwidth. oCSI may for instance comprise and / or correspond to CQI, for a channel (e.g., to be) transmitted in a bandwidth at least partially outside the first bandwidth of the first reference signal. Without loss of generality, it is understood that oCSI may comprise a Precoding Matrix Indicator applicable and / or valid outside the first bandwidth, oPM I, , a Channel Quality Indicator applicable and / or valid outside the first bandwidth, oCQI, , a Rank Indicator applicable and / or valid outside the first bandwidth, oRI, a Layer Information applicable and / or valid outside the first bandwidth, oLI, , a Interference and Noise indication applicable and / or valid outside the first bandwidth, olaN. Such CSI measures applicable and / or valid outside the first bandwidth may for instance be based on measurements performed outside the first bandwidth and / or inferred from within-band (i.e., within the first bandwidth) measurements. On the other hand, iCSI may comprise iPMI, iCQI, IRI, ILI, olaN, respectively being CSI measures applicable and / or valid inside the first bandwidth, e.g., based on measurements performed in the first bandwidth.

[0042] According to an embodiment of the first and / or second example aspect, the channel state information applicable (e.g., and / or valid) outside the first bandwidth (e.g., the oCSI) is derived (e.g., by the terminal device) by means of a machine learning model (e.g., a neural network)(e.g., trained with prior (e.g., reinforcement learning) or offline (supervised learning) first and / or second RS measurements and related CSI, e.g., and / or further parameters such as identity of the network node, location of the terminal device, weather conditions, time of day, season, date, (e.g., current) number of subscribers, CSI reported by other subscribers and / or combinations thereof) or by other prediction means. The machine learning model may for instance have been trained with (e.g., historical and / or simulated and / or augmented) data. For instance, for a given training step, input data may be provided, for instance comprising at least one property of at least one first reference signal, e.g., its received signal strength. A desired output may be a CSI of another bandwidth, e.g., of a bandwidth neighboring the first bandwidth and / or distances from the first bandwidth, overlapping with the first bandwidth, disjoint with the first bandwidth and / or combinations thereof. For instance, historical (e.g., frequency selective) CSI measurements may be used to train the model by selecting a first bandwidth (e.g., from a set of bandwidths for which CSI is known) as an input, attempting to predict at least one of more of another bandwidth (e.g., selected from the bandwidths for which CSI is known) as an output and computing an error signal by comparing the predicted output CSI for the another bandwidth with the known historical value of the CSI in this another bandwidth. At least one model parameter may then be adjusted to reduce the error signal. This process may be repeated numerous times for different combinations of input and output bandwidths in order to train a model to be able to predict CSI in another bandwidth than a bandwidth for which a reference signal (e.g., the first reference signal) has been obtained and thus for which CSI can be measured. The training may take into account (e.g., as further inputs) other data (e.g., obtained from historical and / or simulated data) such as weather conditions, time (of the day and / or the year), level of occupancy of a current area in which the terminal device is located, a number of (e.g., currently connected, e.g., to the network node) subscribers (e.g., terminal devices), at least one of more CSI reported by other terminal devices in a similar area and / or connected to the same network node (e.g., also referred to as subscribers) and / or combinations thereof.

[0043] A machine learning model may for instance comprise supervised learning model (e.g., trained following a process similar to the one outlined above). Examples may be a support vector machine, a linear regression, a logistic regression, a neural network (e.g., a deep neural network, e.g., a convolutional neural network), nearest neighbor methods, a decision tree and / or forest and / or combinations thereof.

[0044] Alternatively to a machine learning model, at least one analytical expression, a (e.g., human-specified) rule and / or a modelbased estimation (e.g., a physical model of a transmission channel) may be used to determine (e.g., predict and / or estimate) the oCSI. Such analytical expressions and / or rules may for instance take into account at least one further property, in addition to the reference signals, similar to the approach outlined above based on a machine learning model.

[0045] Similar and / or identical approaches may be used for the determination of CQI applicable for channel bandwidths outside the first bandwidth.

[0046] According to an embodiment of the first example aspect, the method further comprises, by the terminal device: receiving a second reference signal transmitted by the network node over a second bandwidth, wherein the channel state information (e.g., oCSI and / or iCSI) is determined additionally based on the second reference signal.

[0047] Properties disclosed with respect to the second reference signal of the second example aspect are also applicable to the second reference signal of the first example aspect.

[0048] The first and second reference signals may thus both be considered when determining CSI. For instance, the second reference signal may be received in a second bandwidth (e.g., different from the first bandwidth) and / or be of a second type (e.g., different from a type of the first reference signal). The two reference signals may thus provide different pieces of information for CSI, which may be combined, e.g., in order to obtained a particularly precise CSI estimation (e.g., within the first and / or the second bandwidth and / or outside at least one of or of both of the first and the second bandwidth). The determining of CSI (be it applicable inside or outside the first and / or second bandwidth) may involve, for instance, a comparison of the two reference signals, e.g., a computation of a difference metric between properties (e.g., received signal strength and / or SNR / SNIR and / or CQI) of the two reference signals and / or a provision of the two reference signals to a model, e.g., a machine learning model.

[0049] According to an embodiment of the first and / or the second example aspect, the first reference signal is received before initiation of a RA procedure by the terminal device, and the second reference signal is received during a RA procedure or after completion of a RA procedure by the terminal device.

[0050] The first and the second reference signal may be received at different time instances.

[0051] A random access procedure may typically mark a beginning connection between a terminal device and a network node. After random access, RA, the network node may require at least some indication of a channel state, e.g., channel quality indication, in order to be able to adjust at least one property of a communication channel (e.g., MCS index) to current transmission conditions. In a first approach of probing the radio interface for current conditions, the RA procedure is completed first and (e.g., only) subsequently, reference signals such as CSI-RS, may be provided by the network node to the terminal device. It has been recognized that it may be advantageous to investigate the radio interface properties earlier than that.

[0052] To this end, the first reference signal may be received before initiation (e.g., before transmitting message MsgA in a 2-steps RA procedure or Msg1 in a 4-steps RA procedure) of the RA procedure. This first reference signal may for instance be a DMRS received on a broadcast channel (e.g., PBCH) or may additionally or alternatively be a different reference signal (e.g., PSS, SSS, or others).

[0053] A second reference signal may then be received during (e.g., during / after MsgA and before MsgB in a 2-steps RA procedure or during / after Msg1 and before Msg4 in a 4-steps RA procedure) and / or after completion of the RA procedure (e.g., after MsgB in a 2-steps RA procedure or Msg4 in a 4-steps RA procedure). As the second reference signal may be provided later in the RA procedure or even after the RA procedure, other types of reference signals may be available for the second reference signal, for instance, CSI-RS.

[0054] According to an embodiment of the first and / or the second example aspect, at least a part of the channel state information (e.g., corresponding to and / or comprising the channel quality indication) is provided to the network node during a RA procedure or after completion of a RA procedure by the terminal device (e.g., after the terminal device transitions to an RRC CONNECTED state)(e.g., wherein another part, e.g., based on the first reference signal, is provided before (e.g., completion or start of) a RA procedure).

[0055] For instance, a first CSI (e.g., comprising and / or corresponding to CQI) based on the first reference signal may be provided during the RA procedure, in particular if the first reference signal is received before the RA procedure. Additionally or alternatively, a second CSI (e.g., comprising and / or corresponding to a second CQI; e.g., providing a basis for computing CQI, e.g., based on the first and the second CSI)(e.g., instead of or in addition to the first CSI) based (e.g., on the first and) at least partially on the second reference signal may be provided during the RA procedure, e.g. wherein the second reference signal is obtained during (e.g., or even before) the RA procedure. First CSI (e.g., comprising and / or corresponding to CQI) may be provided in a first uplink message (e.g., MsgA in 2-steps RA or Msg1 or Msg3 in 4-steps RA) whereas second CSI (e.g., comprising and / or corresponding to CQI) may be provided in a second uplink message (e.g., in another PUCCH / PUSCH signaling after RA procedure). Also, for instance, CSI (e.g., comprising and / or corresponding to CQI) based on the first and second reference signal may be provided during (e.g., in MsgA in 2-steps RA or Msg1 or Msg3 in 4-steps RA) or after RA. For instance, second CSI (e.g., comprising and / or corresponding to CQI) may be provided after the RA procedure, e.g., after first CSI (e.g., comprising and / or corresponding to CQI) has been provided during the RA procedure.

[0056] According to an embodiment of the first (e.g., and / or the second) example aspect, the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and the second reference signal is at least one of: a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / Msg B)), a channel-state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CS I -RS)(e. g., received after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH).

[0057] According to an embodiment of the first and / or the second example aspect, at least one of the first reference signal is a first Demodulation Reference Signal, DM-RS, of a broadcast channel, and the second reference signal is at least one of a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / MsgB)), a channel-state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CS l-RS)(e. g., received after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH), the first reference signal is a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / Msg B)), and the second reference signal is at least one of a channel-state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CS l-RS)(e. g., received after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH), or the first and the second reference signals are channel-state information reference signals, CSI-RS, configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CSI- RS)(e.g., received after completion of an RA procedure). For instance, the second reference signal may comprise and / or correspond to a CSI-RS. The CSI-RS may in particular be configured for the terminal device. In this case second reference signal and the CSI (e.g., CQI)(e.g., based on the first and the second reference signal) are sent after completion of the RA procedure. For instance, an RRC-configured reference signal may be used as the second reference signal. In this case, the second reference signal is received by the terminal device after completion of an RA procedure, e.g., because the second reference signal needs to be configured first.

[0058] For instance, the second reference signal may comprise and / or correspond to a DM-RS of a PDCCH wherein the PDCCH schedules a downlink message of an RA procedure, in particular at least one or more of Msg2 / Msg4 (of a 4-steps RA) or MsgB (of a 2-steps RA), e.g., during a RA procedure. Additionally or alternatively, the second reference signal may comprise and / or correspond to a DM-RS of a PDSCH transmission during a RA procedure (e.g., at least one or more of Msg2 / Msg4 / MsgB). In these cases, the CSI (e.g., CQI)(e.g., based on the first and the second reference signal) may for instance be sent during the RA procedure.

[0059] It has been recognized that a PDCCH / PDSCH transmission during a RA procedure may use a wider bandwidth compared to PBCH transmission. Thus, a combination of a first reference signal (e.g., received over PBCH) and a second reference signal (e.g., relating to PDCCH / PDSCH, e.g., during the RA procedure) may provide mutually complementary information about the channel.

[0060] According to an embodiment of the first and / or the second example aspect, the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth, surrounds the first bandwidth (e.g., to both higher and lower frequencies), complementary to the first bandwidth (e.g., wherein a gap in the second bandwidth corresponds to the first bandwidth), or corresponding to (e.g., is identical to or has identical span to) a communication bandwidth or a bandwidth part, BWP, configured for a (e.g., to be established and / or used) data channel (e.g., PDSCH, PUSCH).

[0061] The first and second bandwidth may be different from one another. In particular, they may be at least partially disjoint (e.g., there exists at least one frequency range covered by one bandwidth but not by the other). Additionally or alternatively, they may be entirely disjoint, i.e., free of any overlap in frequency with one another. For instance, the second bandwidth may encompass (e.g., fully contain) and / or surround the first bandwidth (e.g., or vice versa). For instance, first and second bandwidth may be complementary to one another, e.g., at least essentially disjoint yet in combination covering a (e.g., contiguous) bandwidth of interest, e.g., a channel bandwidth, e.g., a bandwidth of a future (e.g., data) channel, e.g., for which a CQI is to be determined (e.g., by the terminal and / or by the network node).

[0062] According to an embodiment of the first and / or the second example aspect, the channel state information comprises at least one (e.g., and / or corresponds to)(e.g., wherein an individual of the below may be based on the first and / or second reference signal) of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals (e.g., a difference and / or a ratio between qualities (e.g., signal strengths and / or signal strength indications) or at least two of the reference signals), or a channel quality indication (e.g., Channel Quality Indicator, CQI) indicative of a (e.g., radio link) quality of the broadcast channel or of a (e.g., future and / or to be established) communication channel (e.g., downlink, DL, and / or uplink, UL, channel)(e.g., data channel, e.g., PDSCH and / or PUSCH).

[0063] For instance, the CSI may comprise an absolute indication of a property of one reference signal (e.g., a signal strength of the first reference signal) and may additionally comprise a relative indication of a property of another reference signal (e.g., a signal strength of the second reference signal, e.g., in relation to the first reference signal).

[0064] For instance, a differential CSI may be determined (e.g., computed) based on a second RS measurement with respect to the first RS measurement.

[0065] According to an embodiment of the first and / or the second example aspect, at least one of the channel quality indication (e.g., Channel Quality Indicator, CQI) is indicative of a (e.g., radio link) quality of a (e.g., future and / or to be established) communication channel (e.g., downlink, DL, and / or uplink, UL, channel)(e.g. , data channel, e.g., PDSCH and / or PUSCH) or the channel quality indication is used for link adaptation towards the terminal device. Link adaption may for instance comprise selecting a MCS index, e.g., by the network node.

[0066] According to an embodiment of the first and / or the second example aspect, the method further comprises, by the terminal device, obtaining (e.g., receiving)(e.g., from the network node) at least one modulation and / or coding indication (e.g., MCS index) to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on (e.g., in response to the providing of) the (e.g., obtained and / or determined) channel state information (e.g., comprising and / or correspond to oCSI, iCSI and / or CQI).

[0067] According to an embodiment of the first and / or the second example aspect, the method further comprises, by the terminal device, obtaining (e.g., receiving)(e.g., from the network node) at least one modulation and / or coding indication (e.g., MCS index) from the network node, wherein the at least one modulation and / or coding indication is at least partially based on the (e..g, obtained or determined) channel quality indication (e.g., the outside channel state information).

[0068] According to a third example aspect, a method is proposed (e.g., performed and / or controlled by a network node), comprising, by a network node transmitting a first reference signal (e.g., DeModulation Reference Signal, DMRS) of a broadcast channel to a (e.g., at least one) terminal device (e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way) over a first bandwidth (e.g., broadcast channel, BCH; e.g., Physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session), obtaining (e.g., receiving) channel state information (e.g., a reference signal strength; a (e.g., differential) quality metric, e.g., of a channel, a CQI of a future channel (e.g., PDSCH, PUSCH))(e.g., indicative of at least one physical property and / or characteristic of a (e.g., DL) radio channel (CQI, RSRP, RSRQ, SNIR, path loss, spatial / M I MO properties) from the terminal device, wherein the channel state information is at least partially based on the transmitted first reference signal.

[0069] According to a fourth example aspect, a method is proposed (e.g., performed and / or controlled by a network node), comprising, by a network node, transmitting a first reference signal (e.g., DeModulation Reference Signal, DMRS) of a broadcast channel to a (e.g., at least one) terminal device (e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way) over a first bandwidth (e.g., broadcast channel, BCH; e.g., Physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session), transmitting a second reference signal to the terminal device (e.g., after the transmitting of the first reference signal) over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal, obtaining (e.g., receiving) a channel quality indication (e.g., to be used for radio link adaption) from the terminal device, wherein the channel quality indication is at least partially based on the transmitted first reference signal and the transmitted second reference signal.

[0070] The method according to the third and / or fourth example aspect may for instance be performed and / or controlled by an apparatus, for instance a server. Alternatively, the method may be performed and / or controlled by more than one apparatus, for instance a server cloud comprising at least two servers. Alternatively, the method may for instance be performed and / or controlled by an electronic device, e.g. a node in a communication system and / or by a terminal device, e.g., a user equipment (UE). For instance, the method may be performed and / or controlled by using at least one processor of the electronic device.

[0071] According to a further example aspect, a computer program is disclosed, the computer program when executed by a processor causing an apparatus, for instance a server, a network node or a terminal device, e.g., a UE, to perform and / or control the actions of the method according to the third and / or fourth example aspect.

[0072] The computer program may be stored on computer-readable storage medium, in particular a tangible and / or non-transitory medium. The computer readable storage medium could for example be a disk or a memory or the like. The computer program could be stored in the computer readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer readable storage medium may be intended for taking part in the operation of a device, like an internal or external memory, for instance a Read-(e.g., Only) Memory (ROM) or hard disk of a computer, or be intended for distribution of the program, like an optical disc.

[0073] According to a further example aspect, an apparatus is disclosed, configured to perform and / or control or comprising respective means for performing and / or controlling the method according to the third and / or fourth example aspect.

[0074] The means of the apparatus can be implemented in hardware and / or software. They may comprise for instance at least one processor for executing computer program code for performing the required functions, at least one memory storing the program code, or both. Alternatively, they could comprise for instance circuitry that is designed to implement the required functions, for instance implemented in a chipset or a chip, like an integrated circuit. In general, the means may comprise for instance one or more processing means or processors. The above-disclosed apparatus according to any aspect may be a module or a component for a device, for example a chip. Alternatively, the disclosed apparatus according to any aspect may be a device, for instance a server or server cloud. The disclosed apparatus according to any aspect may comprise (e.g., only) the disclosed components, for instance means, processor, memory, or may further comprise one or more additional components.

[0075] Features disclosed with respect to the first and / or second aspect are herewith disclosed for the third and fourth aspect as well, where applicable.

[0076] According to an embodiment of the third and / or the fourth example aspect, obtaining the channel state information comprises receiving the channel state information as part of a time-unsynchronized uplink transmission (e.g.,, an uplink signal transmission before applying a (e.g., correct) timing advance correction to an uplink transmission timing) or as part of a random access, RA, procedure (e.g., as part of MsgA of a 2-steps RA procedure, or as part of Msg1 / PRACH preamble or Msg3 of a 4-steps RA procedure).

[0077] According to an embodiment of the third and / or the fourth example aspect, the channel state information comprises channel state information applicable (e.g., and / or valid) outside the first bandwidth (oCSI, e.g., in addition or alternative to to iCSI).

[0078] According to an embodiment of the third and / or the fourth example aspect, the method further comprises, by the network node, deriving channel state information applicable (e.g., and / or valid) outside the first bandwidth (e.g., oCSI) at least partially based on the obtained channel state information.

[0079] For instance, the network node receives from the terminal device CSI, e.g., not yet CQI for a particular channel but for instance signal strength measurements of at least one reference signal provided by the network node. The network node may then determine oCSI itself. The network node may additionally or alternatively determine CQI, e.g., for a channel (e.g., to be) transmitted in a bandwidth at least partially outside the first bandwidth of the first reference signal.

[0080] According to an embodiment of the third and / or the fourth example aspect, the channel state information applicable (e.g., and / or valid) outside the first bandwidth are derived (e.g., by the network node or by the terminal device) by means of a machine learning model (e.g., a neural network)(e.g., trained with prior (e.g., reinforcement learning) or offline (supervised learning) first and / or second RS measurements and related CSI, e.g., and / or further parameters such as identity of the network node, location of the terminal device, weather conditions, time of day, season, date, (e.g., current) number of subscribers, CSI reported by other subscribers and / or combinations thereof) or by other prediction means.

[0081] According to an embodiment of the third example aspect, the method further comprises, by the network node: transmitting a second reference signal to the terminal device over a second bandwidth, wherein the channel state information (e.g., comprising oCSI and / or CQI) is (e.g., determined, e.g., by the terminal device or the network node) additionally based on the second reference signal.

[0082] According to an embodiment of the third and / or the fourth example aspect, the first reference signal is transmitted before initiation of a RA procedure by the terminal device, and the second reference signal is transmitted during a RA procedure or after completion (e.g., an assumed completion, e.g., based on a timer) of a RA procedure by the terminal device (e.g., and / or by the network node).

[0083] According to an embodiment of the third and / or the fourth example aspect, at least a part of the channel state information is obtained from the terminal device during a RA procedure or after completion of a RA procedure by the terminal device (e.g., after the terminal device transitions to an RRC CONNECTED state)(e.g., wherein another part, e.g., based on the first reference signal, is provided before (e.g., completion or start of) a RA procedure).

[0084] According to an embodiment of the third and / or the fourth example aspect, at least a part of the channel quality indication is obtained from the terminal device during a RA procedure or after completion of a RA procedure by the terminal device (e.g., after the terminal device transitions to an RRC CONNECTED state)(e.g., wherein another part, e.g., based on the first reference signal, is provided before (e.g., completion or start of) a RA procedure).

[0085] According to an embodiment of the third and / or the fourth example aspect, the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and the second reference signal is at least one of: a reference signal used for the demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / Msg B)), a channel state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CS I -RS)(e. g., transmitted after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH).

[0086] According to an embodiment of the third and / or the fourth example aspect, at least one of the first reference signal is a first Demodulation Reference Signal, DM-RS, of a broadcast channel, and the second reference signal is at least one of a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / MsgB)), a channel-state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CS l-RS)(e. g., received after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH), the first reference signal is a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure (e.g., DM-RS of a PDCCH scheduling Msg2 / Msg4 / MsgB during a RA procedure or DM-RS of a PDSCH transmission during a RA procedure (Msg2 / Msg4 / Msg B)), and the second reference signal is at least one of a channel-state information reference signal, CSI-RS configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CSI-RS)(e.g., received after completion of an RA procedure), or a reference signal used for demodulation of a downlink data channel (e.g., PDSCH),or the first and second reference signals are channel-state information reference signals, CSI-RS, configured for the terminal device (e.g., (zero-power, ZP and / or non-zero-power NZP) channel state information reference signal, CSI- RS)(e.g., received after completion of an RA procedure).

[0087] According to an embodiment of the third and / or the fourth example aspect, the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth, surrounds the first bandwidth (e.g., to both higher and lower frequencies), complementary to the first bandwidth (e.g., wherein a gap in the second bandwidth corresponds to the first bandwidth), or corresponding to (e.g., is identical to or has identical span to) a communication bandwidth or a bandwidth part, BWP, configured for a (e.g., to be established and / or used) data channel (e.g., PDSCH, PUSCH).

[0088] According to an embodiment of the third and / or the fourth example aspect, the channel state information comprises at least one (e.g., and / or corresponds to)(e.g., wherein an individual of the below may be based on the first, second and / or a third reference signal) of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals (e.g., a difference and / or a ratio between qualities (e.g., signal strengths and / or signal strength indications) or at least two of the reference signals), or a channel quality indication (e.g., Channel Quality Indicator, CQI) indicative of a (e.g., radio link) quality of the broadcast channel or of a (e.g., future and / or to be established) communication channel (e.g., downlink, DL, and / or uplink, UL, channel)(e.g., data channel, e.g., PDSCH and / or PUSCH).

[0089] According to an embodiment of the third and / or the fourth example aspect, at least one of the channel quality indication (e.g., Channel Quality Indicator, CQI) is indicative of a (e.g., radio link) quality of a (e.g., future and / or to be established) communication channel (e.g., downlink, DL, and / or uplink, UL, channel)(e.g. , data channel, e.g., PDSCH and / or PUSCH) or the channel quality indication is used for link adaptation towards the terminal device.

[0090] According to an embodiment of the third and / or the fourth example aspect, the method further comprises, by the network node, providing at least one modulation and / or coding indication (e.g., MCS index) to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on the (e.g., obtained and / or determined) channel state information (e.g., the outside channel state information).

[0091] According to an embodiment of the third and / or the fourth example aspect, the method further comprises, by the network node, providing at least one modulation and / or coding indication (e.g., MCS index) to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on the (e..g, obtained or determined) channel quality indication (e.g., the outside channel state information).

[0092] The features and example embodiments of the invention described above may equally pertain to the different aspects according to the present invention.

[0093] It is to be understood that the presentation of the invention in this section is merely by way of examples and non-limiting.

[0094] Other features of the invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not drawn to scale and that they are merely intended to conceptually illustrate the structures and procedures described herein.

[0095] BRIEF DESCRIPTION OF THE DRAWINGS

[0096] In the figures show:

[0097] Fig. 1 a schematic visualization of a communication system to embodiments of all example aspects;

[0098] Fig. 2 a schematic overview in frequency and time according to embodiments of all example aspects;

[0099] Fig. 3 a schematic signaling diagram of a method according to embodiments of all, in particular the first and third example aspect;

[0100] Fig. 4 a schematic signaling diagram of a method according to embodiments of all, in particular the second and fourth example aspect;

[0101] Fig. 5 a schematic diagram of a relationships between first and second bandwidth according to embodiments of all example aspects;

[0102] Fig. 6 a schematic overview in frequency and time according to embodiments of all example aspects;

[0103] Fig. 7a, b schematic signaling diagrams of methods according to embodiments of all example aspect;

[0104] Fig. 8 a flowchart showing an example embodiment of a method according to the first example aspect;

[0105] Fig. 9 a flowchart showing an example embodiment of a method according to the second example aspect;

[0106] Fig. 10 a flowchart showing an example embodiment of a method according to the third example aspect;

[0107] Fig. 11 a flowchart showing an example embodiment of a method according to the fourth example aspect;

[0108] Fig. 12 a schematic block diagram of an apparatus configured to perform the method according to the first and / or second example aspect;

[0109] Fig. 13 a schematic block diagram of an apparatus configured to perform the method according to the third and / or fourth example aspect; and

[0110] Fig. 14 a schematic illustration of examples of tangible and non-tangible storage media according to all example aspects.

[0111] Fig. 1 demonstrates a simplified communication system, in which methods according to all aspects may be performed. The system comprises a mobile device 100 which may for instance be configured to control and / or perform the method according to the first and / or the second example aspect. The system further comprises a network node 200 which may for instance be configured to control and / or perform the method according to the third and / or fourth example aspect.

[0112] Fig. 2 shows a schematic diagram in the frequency- time domain visualizing reference signals on a broadcast channel. A network node (e.g., the apparatus performing and / or controlling the method according to the third and / or fourth example aspect) may provide first reference signals (e.g., Primary Synchronization Signal, PSS, a Secondary Synchronization Signal, SSS) and / or a DMRS signal to one or more terminal devices (e.g., an apparatus performing and / or controlling the method according to the first and / or second example aspect). The first reference signal(s) may be sent on a broadcast channel such as the Physical Broadcast CHannel, PBCH. The first reference signal(s) may be recipient-agnostic and / or -independent. For instance, the network node may not have access to information on if and yet by how many terminal devices the first reference signal is received. For instance, the first reference signal mal be transmitted periodically, e.g., like shown in Fig. 2 every 20ms.

[0113] The right part of Fig. 2 visualizes the bandwidths involved. There is a total system bandwidth within which a narrower broadcast channel bandwidth, here PBCH bandwidth is shown. A first reference signal (e.g., PBCH DMRS) may be sent over a first bandwidth shown as PBCH DMRS bandwidth in Fig. 2. Thus, a terminal device receiving the first reference signal may be enabled to estimate a channel state information within the first bandwidth, e.g., by measuring a signal strength, e.g., RSSI, SNR, SNIR and / or combinations thereof. At the same time, there exist part of the system bandwidth over which the first reference signal is not sent, shown as Non PBCH DMRS bandwidths. While no direct measurement of channel state information may be possible based on the first reference signal (confined to PBCH DMRS bandwidth), a channel state information applicable to such bandwidth outside the first bandwidth (referred to as oCSI herein) may be possible. To this end, for instance, prediction means such as for instance machine learning models, e.g., artificial neural networks may be used by either terminal device and / or the network node.

[0114] Fig. 3 illustrates an information flow between a network node 200 (e.g., an apparatus performing and / or controlling the method according to the third and / or fourth example aspect) and a terminal device (e.g., an apparatus performing and / or controlling the method according to the first and / or second example aspect) as a signaling diagram. The shown embodiment relates in particular to the first and third aspect but is generally applicable to all example aspects. For instance, in a step S301, the network node 200 may provide a first reference signal RS1 of a first type and in a first bandwidth to the terminal device 100. The reference signal may for instance correspond to and / or comprise a PBCH DMRS and / or any other reference signal receivable by the terminal device 100. RS1 may be transmitted before and / or during a random access, RA, procedure. The terminal device 100 may in step S302 determine channel state information at least based on the received reference signal RS1. CSI may be applicable to the first bandwidth. For instance, such CSI determination may comprise determining a received signal strength of the first reference signal RS1 in the first bandwidth.

[0115] In step S303, the terminal device 100 may provide (e.g., transmit) the determined CSI (e.g., indicative of a signal strength of the reference signal RS1 , a type of reference signal RS1 , a time stamp, a network node identifier (e.g., of a network node from which the reference signal has been obtained) and / or combinations thereof to the network node 200. For instance, such transmission in step S303 may be performed as part of a random access, RA, procedure, for instance in a MsgA of a 2-steps RA procedure or in a Msg 1 or Msg3 of a 4-steps RA procedure. Additionally or as an alternative to steps S302 and S303, the terminal device 100 may determine and provide channel state information going the first bandwidth and / or measures such as channel quality indication, e.g., for a channel such as for instance a (e.g., future) data channel, e.g., a PDSCH. Such further steps are shown in Fig. 3 as an example step S304, wherein an extrapolated CSI which is valid outside the first bandwidth is determined, e.g., by prediction means such as a machine learning model. For instance, such extrapolated CSI may correspond to the oCSI applicable and / or valid outside the first bandwidth. The general oCSI may however be determined by means other than extrapolation.

[0116] In a step S305, the extrapolated CSI and / or other information such as CQI of a future (e.g., data) channel and / or other oCSI may be provided to the network node 200 by the terminal device 100. Such provision may be performed alternatively or additionally to step S303 and / or by the same means, i.e., in particular as part of a random access, RA, procedure, for instance in a MsgA of a 2-steps RA procedure or in a Msg 1 or Msg3 of a 4-steps RA procedure.

[0117] In an optional step S306 (e.g., if CSI is obtained in step S303, for instance if the terminal device 100 (e.g., only) provides (e.g., raw) measurements of CSI (e.g., valid and / or applicable (e.g., only) within the first bandwidth), the network node 200 may perform a determination of “extrapolated CSI”, i.e., of at least one of a channel quality indication for a (e.g., future)(e.g., data) channel, e.g., for a PDSCH, e.g., used and / or usable for link adaptation, and / or oCSI, i.e., CSI applicable and / or valid outside the first bandwidth. To this end, prediction means alike those used by the terminal device 100 in step S304 may be used by the network node 200.

[0118] In a further step S307, the network node may determine at least one modulation and coding scheme, MCS, indication, for instance an MCS index, e.g., based on the CSI and / or the extrapolated CSI (e.g., CQI, oCSI and / or combinations thereof). The MCS indication may be provided in a step S308, for instance also as part of a RA procedure, for instance in a MsgB of a 2-steps RA procedure or Msg2 and / or Msg4 of a 4-steps RA procedure. Alternatively, the MCS indication may be provided after a completed RA procedure, for instance by Downlink Control Information, DCI, Radio Resource Control, RRC, and / or a Medium Access Control, MAC, signaling and / or combinations thereof.

[0119] Fig. 4 illustrates an information flow between a network node 200 (e.g., an apparatus performing and / or controlling the method according to the third and / or fourth example aspect) and a terminal device (e.g., an apparatus performing and / or controlling the method according to the first and / or second example aspect) as a signaling diagram. The shown embodiment relates in particular to the second and fourth aspect but is generally applicable to all example aspects. At least some steps may at least may at least partially correspond to respective steps of Fig. 3, in particular step S401 may correspond to S301, S403 to S302 and / or S304, S404 to S303 and / or S305, S405 to S306, S405 to S307, and S406 to S308. Additionally, a second reference signal RS2 of a second reference signal type and within a second bandwidth is transmitted from the network node 200 to the terminal device 100. The second bandwidth may differ from the first bandwidth. The type of the second reference signal may differ from a type of the first reference signal. For instance, RS1 (step S401) may be received before start of a RA procedure between the terminal device 100 and the network node 200. For instance, RS2 (step 402) may be received during such an RA procedure.

[0120] The terminal device may, in a step S403, determine a channel quality indication, CQI. The CQI may be applicable to a channel, e.g., to a (e.g., future)(e.g., data) channel, e.g., to a PDSCH. The determination in step S403 is based on both reference signals RS 1 and RS2. For instance, prediction means may be used by the terminal device 100 in order to determine CQI which may for instance relate to channel bandwidths outside the first and / or second bandwidth.

[0121] The determined CQI may be provided, in a step S404 to the network node 200. Such providing may be performed as part of a RA procedure, for instance in a MsgA of a 2-steps RA procedure or in a Msg 1 or Msg3 of a 4-steps RA procedure. For instance, additional or alternative to the terminal device 100 determining the CQI, the network node 200 may determine a CQI. For instance, the terminal device 100 may, alternatively or additionally to providing CQI, provide (e.g., raw) measurements (e.g., CSI) of the first and second reference signals (RS1 , RS2) to the network node 200. The network node may use the CQI and / or the measurements of the two reference signals RS1 , RS2, in order to determine a CQI. To this end, prediction means may be used, e.g., based on at least one model-based estimation, at least one machine learning model and / or combinations thereof.

[0122] The network node 200 may use the received and / or determined CQI in step S406 in a MCS index determination and provide the MCS index (e.g., in a way as disclosed with respect to Fig. 3).

[0123] Fig. 5 illustrates different relationships between a first bandwidth, BW, of a first reference signal RS1 and a second bandwidth of a second reference signal RS2. The first bandwidth of RS1 is shown to the left and its borders are visualized as dashed lines. The second bandwidth of RS2 may for instance, as shown for RS2a be (e.g., equally sized in frequency to the first BW (e.g., of smaller or larger) yet shifted towards higher frequencies (e.g., or lower frequencies) and overlapping with the first bandwidth. Alternatively, the first bandwidth of RS1 and the second bandwidth of RS2b may be disjoint, e.g., wherein RS2b is on transmitted on higher frequencies as shown or alternatively, on lower frequencies compared to RS1. In the second reference signal RS2c, the second bandwidth (e.g., fully) encompasses the first bandwidth of RS1 , additionally covers higher frequencies and the two bandwidths are aligned in a lower end of the first and second bandwidth. Similarly, second reference signal RS2d also encompasses the first bandwidth, is larger towards lower frequencies yet finishes flush with the upper end of the first bandwidth. In a further example, the reference signal RS2e has a larger extent in both direction (towards higher and lower frequencies) than the first bandwidth and encompasses the first bandwidth.

[0124] Fig. 5 also shows a bandwidth BW1 which may correspond to a bandwidth of a (e.g., data)(e.g., downlink) channel, e.g., a PDSCH. In an example second reference signal RS2f, the second bandwidth is split into two parts and the first and the second reference signals are complementary to one another in relation to the bandwidth BW1, i.e., together cover the (e.g., entire) bandwidth BW1. For instance, the second bandwidth of RS2f does not need to be split but may alternatively be contiguous. For instance, the first bandwidth of RS1 may be flush with a lower (e.g., or higher) end of BW1 and the second bandwidth of the second reference signal may be flush with a higher (e.g. or lower) end of BW1 , wherein the first and second bandwidths complement one another to form the (e.g., entire) BW1. In another example, the second reference signal RS2g may cover the (e.g., entire) BW1 ,

[0125] Fig. 6 is an example embodiment comprising various reference signals. In a time tO (e.g., before an RA procedure), a PBCH DMRS is received as a first reference signal. In t1, a second reference signal is received which may for instance be of a same type (e.g., PBCH DMRS) and / or a same bandwidth compared to the first reference signal or may alternatively have a different type and / or bandwidth compared to the first reference signal. In a third time t2, a further reference signal (e.g., third reference signal) may be received (e.g., additionally to the first and second and / or alternative to the first or the second). The third reference signal may be of a different type and / or a different bandwidth compared to the first and / or second reference signal in tO and t1 . For instance, the third reference signal may comprise at least one subband outside the subband #3 used for the first and / or second reference signal. The third reference signal may have one of the relationships shown in Fig. 5 to the first and / or second reference signal. A further reference signal received at t4 covers an entire channel bandwidth and encompasses the first bandwidth.

[0126] For instance, the UE 100 thus performs a first interference measurement and / or a first CQI computation of a first type on the PBCH DMRS as a first reference signal received on tO. The UE 100 then may perform a second interference measurements / CQI computation on a second reference signal received at t1, e.g., a DMRS (e.g., of a different channel, e.g., a PDCCH used during RA procedure) and / or another reference signal such as ZP and / or NZP CSI-RS, e.g., received on the same and / or on a different transmission bandwidth compared to the first reference signal PBCH DMRS (e.g., interference measurement made based on such first reference signal). For instance if a DMRS is used the second measurement (reference signal 2, t1), it may be understood as a first type measurement. For instance, if non-DMRS symbols are used, the measurement is understood as a second type measurement. The UE may then perform a third interference measurement and / or CQI computation on a third reference signal obtained at t2, e.g., a DMRS / ZP / NZP CSI-RS, in particular outside the transmission bandwidth of the first (e.g., and / or second) reference signal, e.g., interference measurement, of the PBCH DMRS.

[0127] Fig. 7a illustrates a further signaling procedure between a network node 200 (e.g., a apparatus performing and / or controlling the method according to the third and / or fourth example aspect) and a terminal device (e.g., a apparatus performing and / or controlling the method according to the first and / or second example aspect). The signaling diagram may in particular correspond to the embodiment of Fig. 6, wherein the different reference signals of steps S101, S103, S104, S105 are shown. Fig. 7a further illustrates the computation steps performed by the UE 100.

[0128] The UE 100 may, after receiving the first reference signal in tO, compute a first measurement type (M1_Ty1), e.g., an interference, a CQI, An SINR and / or a L1-RSRP. Such first measurement may for instance be provided in a random access response, e.g., in Msg3 as shown in step S102.

[0129] The UE 100 may further compute a (e.g., differential) CQI / interference level between the interference measurements / CQI computation made on the PBCH DMRS (e.g., at tO) and the interference measurements / CQI computation on the DMRS / ZP / NZP CSI-RS (e.g., at t1 above), e.g., on the same bandwidth as the PBCH DMRS. For instance, if a DMRS is used as a type of reference signal in both measurements, the measurements are done at different time instances, and we understood the computation of a same type differential CQI / interference. Alternatively, the reference signals are of different type.

[0130] Steps S104 and S105 relate to measurements at times t3 and t4 of Fig. 6 and may in particular relate to reference signals of a different type (S104) or in a different band (S105). The UE may computes second (e.g., differential) CQI / interference level between the interference measurements and / or CQI computation made on the PBCH DMRS (tO) and the interference measurements and / or CQI computation on the DMRS / ZP / NZP CSI-RS outside the transmission bandwidth (e.g., t2 / t3) as the PBCH DMRS, where if different reference signals are used in both measurements, we understood the computation of a second type differential CQI / interference.

[0131] In steps S106, S107, S108, the various measurements and / or differential metrics are provided to the network node 200, for instance as part of a RA procedure or after it, e.g., by means of UCI, RRC or MAC signaling. Fig. 7b ads a artificial intelligence and / or machine learning functionality, by which a frequency-selective modulation and coding scheme information is determined based on at least one of the obtained measurements (e.g., differential or not) from the UE 100 by the network node 200 using a machine learning model in a step S209. For instance, in an AIML implementation, the measurements at tO and t3 may be used as input in a model which outputs frequency selective (subband) interference / CQI information, e.g., when (e.g., only) tO measurements are performed. A network sided model may receive the tO and t3 measurements and then predict the frequency selective information such that frequency selective MCS scheduling is possible without the transmission, in downlink, of full band reference signals. In this situation, the only need transmission is of the anchor PBCH DMRS as depicted at time t3 in Figures.

[0132] Fig. 8 shows a flowchart of an example embodiment according to the first example aspect, e.g., performed and / or controlled by a terminal device 100.

[0133] In a step M101, the shown method comprises receiving a first reference signal (e.g., DeModulation Reference Signal, DMRS) of a broadcast channel transmitted by a network node (e.g., an apparatus performing and / or controlling the method according to the third and / or fourth example aspect) over a first bandwidth (e.g., e.g., physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session)(e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way).

[0134] In a step M102, the shown method comprises determining channel state information (e.g., a reference signal strength; a (e.g., differential) quality metric, e.g., of a channel, a CQI of a future channel (e.g., PDSCH, PUSCH))(e.g. , indicative of at least one physical property and / or characteristic of a (e.g., DL) radio channel (CQI, RSRP, RSRQ, SNIR, path loss, spatial / MI MO properties) at least partially based on the received first reference signal.

[0135] In a step M103, the shown method comprises providing (e.g., reporting and / or transmitting) the determined channel state information to the network node.

[0136] Fig. 9 shows a flowchart of an example embodiment according to the second example aspect, e.g., performed and / or controlled by a terminal device 100.

[0137] In a step M201, the shown method comprises receiving a first reference signal (e.g., DeModulation Reference Signal, DMRS) transmitted by a network node (e.g., an apparatus performing and / or controlling the method according to the third and / or fourth example aspect) over a first bandwidth (e.g., e.g., physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session)(e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way).

[0138] In a step M202, the shown method comprises receiving a second reference signal transmitted by the network node (e.g., after the transmitting and / or receiving of the first reference signal) over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal. In a step M203, the shown method comprises determining a channel quality indication (e.g., to be used for radio link adaption) at least partially based on the received first reference signal and the received second reference signal.

[0139] In a step M204, the shown method comprises providing (e.g., reporting and / or transmitting) the determined channel quality indication to the network node.

[0140] Fig. 10 shows a flowchart of an example embodiment according to the third example aspect, e.g., performed and / or controlled by a network node 200.

[0141] In a step M301, the shown method comprises transmitting a first reference signal (e.g., DeModulation Reference Signal, DMRS) of a broadcast channel to a (e.g., at least one) terminal device (e.g., an apparatus performing and / or controlling the method according to the first and / or second example aspect) (e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way) over a first bandwidth (e.g., broadcast channel, BCH; e.g., physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session).

[0142] In a step M302, the shown method comprises obtaining (e.g., receiving) channel state information (e.g., a reference signal strength; a (e.g., differential) quality metric, e.g., of a channel, a CQI of a future channel (e.g., PDSCH, PUSCH))(e.g., indicative of at least one physical property and / or characteristic of a (e.g., DL) radio channel (CQI, RSRP, RSRQ, SNIR, path loss, spatial / M I MO properties) from the terminal device, wherein the channel state information is at least partially based on the transmitted first reference signal.

[0143] Fig. 11 shows a flowchart of an example embodiment according to the fourth example aspect, e.g., performed and / or controlled by a network node 200.

[0144] In a step M401, the shown method comprises transmitting a first reference signal (e.g., DeModulation Reference Signal, DMRS) of a broadcast channel to a (e.g., at least one) terminal device (e.g., an apparatus performing and / or controlling the method according to the first and / or second example aspect) (e.g., wherein the broadcast channel is transmitted in a receiver-unspecific way) over a first bandwidth (e.g., broadcast channel, BCH; e.g., physical BCH, PBCH)(e.g., in unsynchronized mode, before performing a random access procedure with the network node and / or without an RRC session).

[0145] In a step M402, the shown method comprises transmitting a second reference signal to the terminal device (e.g., after the transmitting of the first reference signal) over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal.

[0146] In a step M403, the shown method comprises obtaining (e.g., receiving) a channel quality indication (e.g., to be used for radio link adaption) from the terminal device, wherein the channel quality indication is at least partially based on the transmitted first reference signal and the transmitted second reference signal.

[0147] Fig. 12 shows an example block diagram of an apparatus 100 (e.g., performing and / or controlling a method according to the first and / or second example aspect, e.g., a mobile device). The apparatus 100 may perform a method according to the first and / or second example aspect. The apparatus may comprise a user interface A160, a program memory A110, a main memory A120, and a data memory A140. Further, it comprises a processor A130. The apparatus 100 may further comprise functional units reference signal obtainer A131 (e.g., corresponding to method step M101 and / or M201 and M202 of Fig. 8 and 9), a channel state information determiner A132 (e.g., corresponding to method steps M102 and / or M203 of Fig. 8 and 9), a channel state information provider A133 (e.g., correspond to method steps M103 and / or M204 of Fig. 8 and 9). A functional unit may for instance correspond to a code block within a memory A110, A120, A140. The functional units A131, A133 may for instance be connected to and / or control the communication interface A150.

[0148] Fig. 13 shows an example block diagram of an apparatus 200 (e.g., performing and / or controlling a method according to the third and / or fourth example aspect, e.g., a network node). The apparatus 200 may perform a method according to the third and / or fourth example aspect. The apparatus 200 may comprise a user interface A260, a program memory A210, a main memory A220, and a data memory A240. Further, it comprises a processor A230. The apparatus 200 may further comprise functional units: a reference signal transmitter A231 (e.g., corresponding to method steps M301 and / or M401, M402 of Fig. 10 and 11), a channel state information provider A232 (e.g., corresponding to method steps M302 and / or M403 of Fig. 10 and 11). A functional unit may for instance correspond to a code block within a memory A210, A220, A240. The functional units A231, A232 may for instance be connected to and / or control the communication interface A250.

[0149] Fig. 14 is a schematic illustration of examples of tangible and non-transitory computer-readable storage media according to the present invention that may for instance be used to implement program and / or main memory A110, A120, A140, A210, A220, A240 of the apparatus 100 and / or 200 of Fig. 11 and 12. Fig. 14 shows a flash memory 1400, which may for instance be soldered or bonded to a printed circuit board, a solid-state drive 1401 comprising a plurality of memory chips (e.g. Flash memory chips), a magnetic hard drive 1402, a Secure Digital (SD) card 1403, a Universal Serial Bus (USB) memory stick 1404, an optical storage medium 1405 (such as for instance a CD-ROM or DVD) and a magnetic storage medium 1406.

[0150] In summary and / or additionally, new modulation techniques may be specified in future generations of the mobile communication standard. However, potential new modulation technique may have specific characteristics (e.g., oversampling, excess band, interpolated / copied or muted REs, non-integer bit per RE in average, modulation specific overhead, and / or combinations thereof) leading to non-trivial extension or use of 5G NR MCS tables or the like. Such characteristics, and impacting the TBS determination steps to match the modulation capacity. The aspects of this disclosure address the impact of potential new modulations for next generation using a common framework allowing to minimize DCI overhead, providing methods for UE determination steps for at least one parameter needed for TBS determination in UL, DL and / or sidelink, in particular based on legacy MCS tables for indication, and highlighting the required TBS determination intermediate step updates.

[0151] As a result, a common framework is provided to support new modulation techniques without a need for new MCS table per every new technique. The DCI indication overhead is minimized. TBS is aligned with the indicated modulation configuration and issues caused by improper TBS (e.g., smaller and / or greater than available payload) in case the code rate and / or modulation in the indicated MCS row are not aligned with the new effective modulation technique and / or with a new (e.g., advanced) modulation technique, may be avoided. Finer granularity for spectral efficiency is provided and thus better link adaptation. There is no need to introduce additional MCS tables to exploit the capacity of new modulation techniques and thus to achieve higher spectral efficiency.

[0152] Some embodiments comprise: Embodiment 1 :

[0153] A method, comprising, by a terminal device: receiving a first reference signal of a broadcast channel transmitted by a network node over a first bandwidth, determining channel state information at least partially based on the received first reference signal, providing the determined channel state information to the network node.

[0154] Embodiment 2:

[0155] A method, comprising, by a terminal device: receiving a first reference signal transmitted by a network node over a first bandwidth, receiving a second reference signal transmitted by the network node over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal, determining a channel quality indication at least partially based on the received first reference signal and the received second reference signal, and providing the determined channel quality indication to the network node.

[0156] Embodiment 3:

[0157] The method according to embodiment 1 or 2, wherein the channel state information comprises and / or corresponds to a channel quality indication. According to an embodiment of the second example aspect, the channel quality indication may be comprised by and / or correspond to channel state information. In the following, disclosure (e.g., regarding to a determining, an obtaining and / or a providing of) channel state information additionally applies to a channel quality indication and vice versa, where applicable.

[0158] Embodiment 4:

[0159] The method according to any of embodiments 1 to 3, wherein providing the channel state information comprises transmitting the channel state information as part of a time-unsynchronized uplink transmission or as part of a random access, RA, procedure.

[0160] Embodiment 5:

[0161] The method according to any of embodiments 1 to 4, wherein the channel state information comprises channel state information applicable outside the first bandwidth.

[0162] Embodiment 6:

[0163] The method according to any of embodiments 1 to 5, wherein the channel state information applicable outside the first bandwidth are derived by means of a machine learning model or by other prediction means.

[0164] Embodiment / :

[0165] The method according to any of embodiments 1 to 6, further comprising, by the terminal device: receiving a second reference signal transmitted by the network node over a second bandwidth, wherein the channel state information is determined additionally based on the second reference signal.

[0166] Embodiment 8: The method according to any of embodiments 1 to 7, wherein the first reference signal is received before initiation of a RA procedure by the terminal device, and the second reference signal is received during a RA procedure or after completion of a RA procedure by the terminal device.

[0167] Embodiment 9:

[0168] The method according to any of embodiments 1 to 8, wherein at least a part of the channel state information is provided to the network node during a RA procedure or after completion of a RA procedure by the terminal device.

[0169] Embodiment 10:

[0170] The method according to any of embodiments 1 to 9, wherein at least a part of the channel quality indication is provided to the network node during a RA procedure or after completion of a RA procedure by the terminal device.

[0171] Embodiment 11 :

[0172] The method according to any of embodiments 1 to 10, wherein the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and wherein the second reference signal is at least one of: a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel-state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel.

[0173] Embodiment 12:

[0174] The method according to any of embodiments 1 to 11 , wherein at least one of the first reference signal is a first Demodulation Reference Signal, DM-RS, of a broadcast channel, and wherein the second reference signal is at least one of a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel-state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel, the first reference signal is a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, and wherein the second reference signal is at least one of a channel-state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel, or the first and the second reference signals are channel-state information reference signals, CSI-RS, configured for the terminal device.

[0175] Embodiment 12:

[0176] The method according to any of embodiments 1 to 11, wherein the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth, 1 surrounds the first bandwidth, complementary to the first bandwidth, or corresponding to a communication bandwidth or a bandwidth part, BWP, configured for a data channel.

[0177] Embodiment 13:

[0178] The method according to any of embodiments 1 to 12, wherein the channel state information comprises at least one of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals, or a channel quality indication indicative of a quality of the broadcast channel or of a communication channel.

[0179] Embodiment 14:

[0180] The method according to any of embodiments 1 to 13, wherein at least one of the channel quality indication is indicative of a quality of a communication channel or the channel quality indication is used for link adaptation towards the terminal device.

[0181] Embodiment 15:

[0182] The method according to any of embodiments 1 to 14, the method further comprising, by the terminal device, obtaining at least one modulation and / or coding indication from the network node, wherein the at least one modulation and / or coding indication is at least partially based on (e.g., in response to the providing of) the channel state information or obtaining at least one modulation and / or coding indication from the network node, wherein the at least one modulation and / or coding indication is at least partially based on the channel quality indication.

[0183] Embodiment 16:

[0184] A method, comprising, by a network node transmitting a first reference signal of a broadcast channel to a terminal device over a first bandwidth, obtaining channel state information from the terminal device, wherein the channel state information is at least partially based on the transmitted first reference signal.

[0185] Embodiment 17:

[0186] A method, comprising, by a network node transmitting a first reference signal of a broadcast channel to a terminal device over a first bandwidth, transmitting a second reference signal to the terminal device over a second bandwidth, wherein the second reference signal is of a different type than the first reference signal, obtaining a channel quality indication from the terminal device, wherein the channel quality indication is at least partially based on the transmitted first reference signal and the transmitted second reference signal.

[0187] Embodiment 18:

[0188] The method according to embodiment 16 or 17, wherein obtaining the channel state information comprises receiving the channel state information as part of a time-unsynchronized uplink transmission or as part of a random access, RA, procedure. Embodiment 19:

[0189] The method according to any of embodiments 16 to 18, wherein the channel state information comprises channel state information applicable outside the first bandwidth.

[0190] Embodiment 20:

[0191] The method according to any of embodiments 16 to 19, wherein the method further comprises, by the network node, deriving channel state information applicable outside the first bandwidth at least partially based on the obtained channel state information.

[0192] Embodiment 21 :

[0193] The method according to any of embodiments 16 to 20, wherein the channel state information applicable outside the first bandwidth are derived by means of a machine learning model or by other prediction means.

[0194] Embodiment 22:

[0195] The method according to any of embodiments 16 to 21, further comprising, by the network node: transmitting a second reference signal to the terminal device over a second bandwidth, wherein the channel state information is additionally based on the second reference signal.

[0196] Embodiment 23:

[0197] The method according to any of embodiments 16 to 22, wherein the first reference signal is transmitted before initiation of a RA procedure by the terminal device, and the second reference signal is transmitted during a RA procedure or after completion of a RA procedure by the terminal device.

[0198] Embodiment 24:

[0199] The method according to any of embodiments 16 to 23, wherein at least a part of the channel state information is obtained from the terminal device during a RA procedure or after completion of a RA procedure by the terminal device.

[0200] Embodiment 25:

[0201] The method according to any of embodiments 16 to 24, wherein at least a part of the channel quality indication is obtained from the terminal device during a RA procedure or after completion of a RA procedure by the terminal device.

[0202] Embodiment 26:

[0203] The method according to any of embodiments 16 to 25, wherein the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and wherein the second reference signal is at least one of: a reference signal used for the demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel.

[0204] Embodiment 27: The method according to any of embodiments 16 to 26, wherein at least one of the first reference signal is a first Demodulation Reference Signal, DM-RS, of a broadcast channel, and wherein the second reference signal is at least one of a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel-state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel, the first reference signal is a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, and wherein the second reference signal is at least one of a channel-state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel, or the first and second reference signals are channel-state information reference signals, CSI-RS, configured for the terminal device.

[0205] Embodiment 28:

[0206] The method according to any of embodiments 16 to 27, wherein the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth, surrounds the first bandwidth, complementary to the first bandwidth, or corresponding to a communication bandwidth or a bandwidth part, BWP, configured for a data channel.

[0207] Embodiment 29:

[0208] The method according to any of embodiments 16 to 28, wherein the channel state information comprises at least one of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals, or a channel quality indication indicative of a quality of the broadcast channel or of a communication channel.

[0209] Embodiment 30:

[0210] The method according to any of embodiments 16 to 29, wherein at least one of the channel quality indication is indicative of a quality of a communication channel or the channel quality indication is used for link adaptation towards the terminal device.

[0211] Embodiment 31 :

[0212] The method according to any of embodiments 16 to 30, further comprising, by the network node, providing at least one modulation and / or coding indication to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on the channel state information, or providing at least one modulation and / or coding indication to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on the channel quality indication. Embodiment 32:

[0213] A first apparatus, e.g., a UE, comprising respective means for performing the method of any of Embodiments 1 to 15.

[0214] Embodiment 33:

[0215] A first apparatus, e.g., a UE, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform and / or control the method according to any of embodiments 1 to 15.

[0216] Embodiment 34:

[0217] A second apparatus, e.g., a network node, comprising respective means for performing the method of any of Embodiments 16 to 31.

[0218] Embodiment 35:

[0219] A second apparatus, e.g., a network node, comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform and / or control the method according to any of embodiments 16 to 31.

[0220] Embodiment 36:

[0221] A computer program, the computer program when executed by a processor causing an apparatus, e.g. the apparatus according to embodiment 32 or 33, to perform and / or control the actions and / or steps of the method of any of embodiments 1 to 15.

[0222] Embodiment 37:

[0223] A computer program product comprising a computer program according to embodiment 36.

[0224] Embodiment 38:

[0225] A computer program, the computer program when executed by a processor causing an apparatus, e.g. the apparatus according to embodiment 34 or 35, to perform and / or control the actions and / or steps of the method of any of embodiments 16 to 31.

[0226] Embodiment 39:

[0227] A computer program product comprising a computer program according to embodiment 38.

[0228] Embodiment 40:

[0229] A system comprising: at least one first apparatus according to any of the embodiments 32 or 33; and at least one second apparatus according to any of the embodiments 34 or 35.

[0230] Any presented connection in the described embodiments is to be understood in a way that the involved components are operationally coupled. Thus, the connections can be direct or indirect with any number or combination of intervening elements, and there may be merely a functional relationship between the components. Further, as used in this text, the term ‘circuitry’ refers to any of the following:

[0231] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry)

[0232] (b) combinations of circuits and software (and / or firmware), such as: (i) to a combination of processor(s) or (ii) to sections of processor(s) / software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone, to perform various functions) and

[0233] (c) to circuits, such as a microprocessor(s) or a section of a microprocessor(s), that re-quire software or firmware for operation, even if the software or firmware is not physically present.

[0234] This definition of ‘circuitry’ applies to all uses of this term in this text, including in any claims. As a further example, as used in this text, the term ‘circuitry’ also covers an implementation of merely a processor (or multiple processors) or section of a processor and its (or their) accompanying software and / or firmware. The term ‘circuitry’ also covers, for example, a baseband integrated circuit or applications processor integrated circuit for a mobile phone.

[0235] Any of the processors mentioned in this text, in particular but not limited to processors 130, 230 of Figs. 7 and 8, could be a processor of any suitable type. Any processor may comprise but is not limited to one or more microprocessors, one or more processor(s) with accompanying digital signal processor(s), one or more processor(s) without accompanying digital signal processor(s), one or more special-purpose computer chips, one or more field-programmable gate arrays (FPGAS), one or more controllers, one or more application-specific integrated circuits (ASICS), or one or more computer(s). The relevant structure / hardware has been programmed in such a way to carry out the described function.

[0236] Moreover, any of the actions or steps described or illustrated herein may be implemented using executable instructions in a general-purpose or special-purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, or the like) to be executed by such a processor. References to 'computer-readable storage medium’ should be understood to encompass specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices.

[0237] Moreover, any of the actions described or illustrated herein may be implemented using executable instructions in a general- purpose or special-purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, or the like) to be executed by such a processor. References to 'computer-readable storage medium’ should be understood to encompass specialized circuits such as FPGAs, ASICs, signal processing devices, and other devices.

[0238] The wording “A, or B, or C, or a combination thereof” or “at least one of A, B and C” may be understood to be not exhaustive and to include at least the following: (i) A, or (ii) B, or (iii) C, or (iv) A and B, or (v) A and C, or (vi) B and C, or (vii) A and B and C.

[0239] It will be understood that the embodiments disclosed herein are only exemplary, and that any feature presented for a particular exemplary embodiment may be used with any aspect of the present disclosure on its own or in combination with any feature presented for the same or another particular exemplary embodiment and / or in combination with any other feature not mentioned. It will further be understood that any feature presented for an example embodiment in a particular category may also be used in a corresponding manner in an example embodiment of any other category.

[0240] LIST OF ABBREVIATIONS

[0241] CQI Channel Quality Indication DL downlink

[0242] DMRS Demodulation Reference Signals

[0243] NZP CSI-RS non-Zero power Channel Reference Signals

[0244] PBCH Physical Broadcast Channel RACH Random Access Channel

[0245] UL Uplink

[0246] ZP CSI-RS Zero power Channel Reference Signals

[0247] NZP CSI-RS Non Zero power Channel Reference Signals

Claims

1.C l a i m s1) A first apparatus comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to perform: receiving a first reference signal of a broadcast channel transmitted by a network node over a first bandwidth, determining channel state information at least partially based on the received first reference signal, and providing the determined channel state information to the network node.2) The first apparatus according to claim 1 , wherein providing the channel state information comprises transmitting the channel state information as part of a time-unsynchronized uplink transmission or as part of a random access, RA, procedure.3) The first apparatus according to claim 1 or 2, wherein the channel state information comprises channel state information applicable outside the first bandwidth.4) The first apparatus according to claim 3, wherein the channel state information applicable outside the first bandwidth are derived by means of a machine learning model or by other prediction means.5) The first apparatus according to claim 1 , wherein the first apparatus is further caused to perform: receiving a second reference signal transmitted by the network node over a second bandwidth, wherein the channel state information is determined additionally based on the second reference signal.6) The first apparatus according to claim 5, wherein the first reference signal is received before initiation of a RA procedure by the first apparatus, and the second reference signal is received during a RA procedure or after completion of a RA procedure by the first apparatus.7) The first apparatus according to claim 6, wherein at least a part of the channel state information is provided to the network node during a RA procedure or after completion of a RA procedure by the first apparatus.8) The first apparatus according to any of claims 5 to 7, wherein the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and wherein the second reference signal is at least one of: a reference signal used for demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel-state information reference signal, CSI-RS configured for the first apparatus, or a reference signal used for demodulation of a downlink data channel.9) The first apparatus according to any of claims 5 to 8, wherein the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth,surrounds the first bandwidth, complementary to the first bandwidth, or corresponding to a communication bandwidth or a bandwidth part, BWP, configured for a data channel.10) The first apparatus according to any of claims 1 to 9, wherein the channel state information comprises at least one of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals, or a channel quality indication indicative of a quality of the broadcast channel or of a communication channel.11) A second apparatus comprising at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to perform: transmitting a first reference signal of a broadcast channel to a terminal device over a first bandwidth, and obtaining channel state information from the terminal device, wherein the channel state information is at least partially based on the transmitted first reference signal.12) The second apparatus according to claim 11, wherein obtaining the channel state information comprises receiving the channel state information as part of a time-unsynchronized uplink transmission or as part of a random access, RA, procedure.13) The second apparatus according to claim 11 or 12, wherein the channel state information comprises channel state information applicable outside the first bandwidth.14) The second apparatus according to claim 11 or 12, wherein the second apparatus is further caused to perform: deriving channel state information applicable outside the first bandwidth at least partially based on the obtained channel state information.15) The second apparatus according to claim 14, wherein the channel state information applicable outside the first bandwidth are derived by means of a machine learning model or by other prediction means.16) The second apparatus according to claim 11 , wherein the second apparatus is further caused to perform: transmitting a second reference signal to the terminal device over a second bandwidth, wherein the channel state information is additionally based on the second reference signal.17) The second apparatus according to claim 16, wherein the first reference signal is transmitted before initiation of a RA procedure by the terminal device, and the second reference signal is transmitted during a RA procedure or after completion of a RA procedure by the terminal device.18) The second apparatus according to claim 17, wherein at least a part of the channel state information is obtained from the terminal device during a RA procedure or after completion of a RA procedure by the terminal device.19) The second apparatus according to any of claims 16 to 18, wherein the first reference signal is: a first Demodulation Reference Signal, DM-RS, of the broadcast channel, and wherein the second reference signal is at least one of: a reference signal used for the demodulation of a downlink transmission during a RA procedure or of a control channel scheduling a downlink transmission during the RA procedure, a channel state information reference signal, CSI-RS configured for the terminal device, or a reference signal used for demodulation of a downlink data channel.20) The second apparatus according to any of claims 16 to 19, wherein the second bandwidth is at least one of: at least partially disjoint from the first bandwidth, encompasses the first bandwidth, surrounds the first bandwidth, complementary to the first bandwidth, or corresponding to a communication bandwidth or a bandwidth part, BWP, configured for a data channel.21) The second apparatus according to any of claims 11 to 20, wherein the channel state information comprises at least one of: a signal strength or quality of the received first reference signal, a signal strength or quality of the received second reference signal, a difference in a channel metric between the received first and second reference signals, or a channel quality indication indicative of a quality of the broadcast channel or of a communication channel.22) The second apparatus according to any of claims 11 to 21 , wherein the second apparatus is further caused to perform: providing at least one modulation and / or coding indication to the terminal device, wherein the at least one modulation and / or coding indication is at least partially based on the channel state information.23) A method comprising, by a terminal device: receiving a first reference signal of a broadcast channel transmitted by a network node over a first bandwidth, determining channel state information at least partially based on the received first reference signal, and providing the determined channel state information to the network node.24) A method, comprising, by a network node: transmitting a first reference signal of a broadcast channel to a terminal device over a first bandwidth, and obtaining channel state information from the terminal device, wherein the channel state information is at least partially based on the transmitted first reference signal.

Images