RRM measurment configuration in communication systems

Abstract

Embodiments of the invention relate to using a control resource comprising an embedded RRM reference signal (550) in a wireless network. Thus, a first communication device (100) configured to: receive a first control message (510) from a second communication device (300), the first control message (510) indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a DRX ON duration of the first communication device (100), the control resource comprising an embedded RRM reference signal (550); determine a RRM measurement based on the embedded RRM reference signal (550); and transmit the RRM measurement to the second communication device (300) based on the RRM measurement configuration. Thereby, power saving in the first communication device (100) is possible. Furthermore, the invention also relates to corresponding methods and a computer program.

Description

[0001] RRM MEASURMENT CONFIGURATION IN COMMUNICATION SYSTEMS

[0002] TECHNICAL FIELD

[0003] Embodiments of the invention relate to a first communication device and a second communication device for RRM measurement configuration in communication systems. Furthermore, embodiments of the invention also relate to corresponding methods and a computer program.

[0004] BACKGROUND

[0005] In 3GPP 5G new radio (NR), data and signaling messages are carried in downlink (DL) and uplink (UL) physical channels, including physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH).

[0006] All these channels are important for guaranteeing multiple functions to make a communication achieving the expected requirements. Among these channels, the role of PDCCH is pivotal in 5G NR systems, and in wireless networks in general. The PDCCH is used for, among others, DL scheduling assignment, UL scheduling grant, slot format indication, preemption indication, power control, channel state information (CSI) reporting triggering, and link adaptation.

[0007] Downlink control information (DCI) is transmitted in the PDCCH. Depending on its format, the DCI may contain different fields, each with a specified use. DCI is subject to multiple processing steps before resulting in a PDCCH payload. The design of PDCCH in 5G NR was developed with the aim of ensuring good coverage and reliability. Detection and correct decoding of PDCCH and the DCI therein are paramount to avoid link failure in the wireless network.

[0008] SUMMARY

[0009] An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

[0010] Another objective of embodiments of the invention is to provide a power saving solution for RRM measurements.

[0011] The above and further objectives are solved by the subject matter of the independent claims.

[0012] Further embodiments of the invention can be found in the dependent claims.

[0013] According to a first aspect of the invention, the above mentioned and other objectives are achieved with a first communication device configured to: receive a first control message from a second communication device, the first control message indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a discontinuous reception, DRX, ON duration of the first communication device, the control resource comprising an embedded RRM reference signal; determine a RRM measurement based on the embedded RRM reference signal; and transmit the RRM measurement to the second communication device based on the RRM measurement configuration.

[0014] An advantage of the first communication device according to the first aspect is that RRM measurements can be performed based on the control resources embedded RRM reference signal. This means that the first communication device may skip waking up to perform RRM measurements outside the DRX-ON duration / period. Consequently, power savings can be achieved at the first communication device, since its active time and sleep state transitions can be reduced. Additionally, depending on the configuration of the control resources embedded RRM reference signal, timely measurements can be maintained and delay to obtain RRM measurements can be reduced.

[0015] In an implementation form of a first communication device according to the first aspect, the RRM measurement configuration indicates a synchronization signal / physical broadcast channel, SS / PBCH, block measurement timing configuration, SMTC, window arranged outside the DRX ON duration; and wherein the first communication device is configured to: skip performing the RRM measurement outside the DRX ON duration when a time offset of the embedded RRM reference signal in relation to the SMTC window arranged outside the DRX ON duration is within a time period Tv

[0016] An advantage with this implementation form is that the first communication device can skip waking up outside the DRX ON duration to perform RRM measurements when certain conditions are verified. One condition being a time gap between RRM reference signal outside DRX ON and control resources embedded RRM reference signal. The condition on the time gap between these signals guarantee that the variation in the outcome of measurements is minimal or acceptable, considering the dynamic nature of radio and channel conditions. Consequently, the first communication device can skip performing RRM measurements outside DRX ON duration without detrimental impact on the accuracy of the derived RRM measurements.

[0017] In an implementation form of a first communication device according to the first aspect, the first communication device is configured to: receive a second control message from the second communication device, the second control message indicating the time period Tv.

[0018] An advantage with this implementation form is that the time period Tvcan be adapted depending on radio and / or load conditions.

[0019] In an implementation form of a first communication device according to the first aspect, the second control message is a radio resource control, RRC, message or a medium access control, MAC, control element, CE, message.

[0020] An advantage with this implementation form is that the time period Tvcan be semi-statically configured or dynamically signaled to the first communication device which provides more flexibility in managing RRM measurements.

[0021] In an implementation form of a first communication device according to the first aspect, the RRM measurement configuration indicates one or more requirements for performing the RRM measurement, and wherein the first communication device is configured to: skip performing the RRM measurement outside the DRX ON duration when the one or more requirements for performing the RRM measurement can be met using the RRM measurements based on the embedded RRM reference signal.

[0022] An advantage with this implementation form is that the first communication device can skip waking up outside DRX ON duration to perform RRM measurements when certain requirements are verified. The requirements guarantee that skipping RRM measurements outside DRX ON and performing the said measurements based on the control resources embedded RRM reference signal, would result in measurement quantities with similar accuracy and validity. The advantage with this implementation form is that measurement skipping will not degrade RRM measurement quality and the same outcomes can be expected. In an implementation form of a first communication device according to the first aspect, the one or more requirements for performing RRM measurements comprises: a measurement quantity, a measurement object, a measurement performance, and a measurement criterion.

[0023] An advantage with this implementation form is that all RRM configuration requirements will be considered when deciding to skip RRM measurements outside DRX ON duration. The first communication device will skip RRM measurements outside DRX ON duration, only when it determines that all the RRM measurement configuration requirements can be verified, based on the control resources embedded RRM reference signal. In this case, it is guaranteed that measurements skipping will not degrade the achievable RRM measurements accuracy. Additionally, the same information, e.g., signal strength or reference signal received power (RSRP) for reference signal from a given cell, can be obtained.

[0024] In an implementation form of a first communication device according to the first aspect, the embedded RRM reference signal is a SS, a preconfigured baseband sequence, or a channel state information reference signal, CSI-RS.

[0025] An advantage with this implementation form is that multiple configurations and mappings of reference signals can be supported for the control resources embedded RRM reference signal. This enables to embed the RRM reference signal in the control resources without having a detrimental impact on the decoding performance of a control channel that may be conveyed in the same resources.

[0026] In an implementation form of a first communication device according to the first aspect, the control resource is a control resource set, CORSET.

[0027] An advantage with this implementation form is that the proposed solution can be used in 5G NR systems.

[0028] In an implementation form of a first communication device according to the first aspect, the CORSET is a common CORSET for a plurality of first communication devices.

[0029] An advantage with this implementation form is that the control resources embedded RRM reference signal can be received at the same time instance by multiple first communication devices. Additionally, since RRM reference signal can be cell specific, different cells can coordinate control resources embedded RRM reference signal transmissions based on UE-common CORESET configurations.

[0030] In an implementation form of a first communication device according to the first aspect, the embedded RRM reference signal is cell-specific or transmission reception point, TRP, specific.

[0031] An advantage with this implementation form is that multiple deployment and communications scenarios can be supported, including multi-TRP, cell free multiple input multiple output (MIMO), carrier aggregation, dual connectivity and mobility management.

[0032] In an implementation form of a first communication device according to the first aspect, the embedded RRM reference signal is transmitted in a periodic, an aperiodic or a semi-persistent manner.

[0033] An advantage with this implementation form is that multiple time domain behaviors can be supported for the control resources embedded RRM reference signal. This enables different approaches for managing the subsequent measurements, e.g., opportunistic RRM measurement triggering and periodic RRM measurement skipping outside DRX ON duration. In an implementation form of a first communication device according to the first aspect, the first communication device is configured to: receive the embedded RRM reference signal after reception of a third control message from the second communication device, the third control message indicating the transmission of the embedded RRM reference signal; or receive the embedded RRM reference signal after transmission of a fourth control message to the second communication device, the fourth control message indicating a request for the transmission of the embedded RRM reference signal.

[0034] An advantage with this implementation form is that the transmission of the control resources embedded RRM reference signal can be triggered by the first communication device or the second communication device. Event triggered transmission of the control resources embedded RRM reference signal is then supported, whether the event is detected at the first communication device or the second communication device. Additionally, dynamic signaling is supported for either control messages, enhancing the flexibility and adaptation of the proposed solution.

[0035] In an implementation form of a first communication device according to the first aspect, the first communication device is configured to: decode a control channel in the control resource when the embedded RRM reference signal has a first pattern; and skip decoding a control channel in the control resource when the embedded RRM reference signal has a second pattern different to the first pattern.

[0036] An advantage with this implementation form is that the proposed solution can be used for control channel decoding enhancements. By enabling multiple possible configurations or patterns for the control resources embedded RRM reference signal and associating each with a subset of control channel candidates, the number of blind decoding can be reduced. In examples, two patterns may be used, one indicating the presence of a control channel signal for the first communication device and one indicating its absence. Consequently, the first communication device can skip control channel decoding when it detects the second pattern, indicating absence of a control channel for the first communication device.

[0037] According to a second aspect of the invention, the above mentioned and other objectives are achieved with a second communication device configured to: transmit a first control message to a first communication device, the first control message indicating at least one RRM measurement configuration; transmit a control resource during a DRX ON duration of the first communication device, the control resource comprising an embedded RRM reference signal; receive a RRM measurement from the first communication device based on the RRM measurement configuration; and manage radio resources for the first communication device based on the RRM measurement.

[0038] An advantage of the second communication device according to the second aspect is that RRM measurements can be performed based on the control resources embedded RRM reference signal. This means that the first communication device may skip waking up to perform RRM measurements outside the DRX-ON duration / period. Consequently, power savings can be achieved at the first communication device, since its active time and sleep state transitions can be reduced. Additionally, depending on the configuration of the control resources embedded RRM reference signal, timely measurements can be maintained and delay to obtain RRM measurements can be reduced.

[0039] In an implementation form of a second communication device according to the second aspect, the RRM measurement configuration indicates a SMTC window arranged outside the DRX ON duration. In an implementation form of a second communication device according to the second aspect, the second communication device is configured to: transmit a second control message to the first communication device, the second control message indicating a time period Tvassociated with the SMTC window.

[0040] An advantage with this implementation form is that the first communication device can skip waking up outside the DRX ON duration to perform RRM measurements when certain conditions are verified. One condition being a time gap between RRM reference signal outside DRX ON and control resources embedded RRM reference signal. The condition on the time gap between these signals guarantee that the variation in the outcome of measurements is minimal or acceptable, considering the dynamic nature of radio and channel conditions. Consequently, the first communication device can skip performing RRM measurements outside DRX ON duration without detrimental impact on the accuracy of the derived RRM measurements.

[0041] In an implementation form of a second communication device according to the second aspect, the second control message is a RRC message or a MAC CE message.

[0042] An advantage with this implementation form is that the time period Tvcan be semi-statically configured or dynamically signaled to the first communication device which provides more flexibility in managing RRM measurements.

[0043] In an implementation form of a second communication device according to the second aspect, the RRM measurement configuration indicates one or more requirements for performing a RRM measurement.

[0044] An advantage with this implementation form is that the first communication device can skip waking up outside DRX ON duration to perform RRM measurements when certain requirements are verified. The requirements guarantee that skipping RRM measurements outside DRX ON and performing the said measurements based on the control resources embedded RRM reference signal, would result in measurement quantities with similar accuracy and validity. The advantage with this implementation form is that measurement skipping will not degrade RRM measurement quality and the same outcomes can be expected.

[0045] In an implementation form of a second communication device according to the second aspect, the one or more requirements for performing the RRM measurement comprises: a measurement quantity, a measurement object, a measurement performance, and a measurement criterion.

[0046] An advantage with this implementation form is that all RRM configuration requirements will be considered when deciding to skip RRM measurements outside DRX ON duration. The first communication device will skip RRM measurements outside DRX ON duration, only when it determines that all the RRM measurement configuration requirements can be verified, based on the control resources embedded RRM reference signal. In this case, it is guaranteed that measurements skipping will not degrade the achievable RRM measurements accuracy. Additionally, the same information, e.g., signal strength or RSRP for reference signal from a given cell, can be obtained.

[0047] In an implementation form of a second communication device according to the second aspect, the embedded RRM reference signal is a SS, a preconfigured baseband sequence, or a CSI-RS.

[0048] An advantage with this implementation form is that multiple configurations and mappings of reference signals can be supported for the control resources embedded RRM reference signal. This enables to embed the RRM reference signal in the control resources without having a detrimental impact on the decoding performance of a control channel that may be conveyed in the same resources.

[0049] In an implementation form of a second communication device according to the second aspect, the control resource is a CORSET.

[0050] An advantage with this implementation form is that the proposed solution can be used in 5G NR systems.

[0051] In an implementation form of a second communication device according to the second aspect, the CORSET is a common CORSET for a plurality of first communication devices.

[0052] An advantage with this implementation form is that the control resources embedded RRM reference signal can be received at the same time instance by multiple first communication devices. Additionally, since RRM reference signal can be cell specific, different cells can coordinate control resources embedded RRM reference signal transmissions based on UE-common CORESET configurations.

[0053] In an implementation form of a second communication device according to the second aspect, the embedded RRM reference signal is cell-specific or TRP specific.

[0054] An advantage with this implementation form is that multiple deployment and communications scenarios can be supported, including multi-TRP, cell free MIMO, carrier aggregation, dual connectivity and mobility management.

[0055] In an implementation form of a second communication device according to the second aspect, the embedded RRM reference signal is transmitted in a periodic, an aperiodic or a semi-persistent manner.

[0056] An advantage with this implementation form is that multiple time domain behaviors can be supported for the control resources embedded RRM reference signal. This enables different approaches for managing the subsequent measurements, e.g., opportunistic RRM measurement triggering and periodic RRM measurement skipping outside DRX ON duration.

[0057] In an implementation form of a second communication device according to the second aspect, the second communication device is configured to: transmit a third control message to the first communication device, the third control message indicating the transmission of the embedded RRM reference signal; or receive a fourth control message from the first communication device prior to transmitting the first control message, the fourth control message indicating a request for the transmission of the embedded RRM reference signal.

[0058] An advantage with this implementation form is that the transmission of the control resources embedded RRM reference signal can be triggered by the first communication device or the second communication device. Event triggered transmission of the control resources embedded RRM reference signal is then supported, whether the event is detected at the first communication device or the second communication device. Additionally, dynamic signaling is supported for either control messages, enhancing the flexibility and adaptation of the proposed solution.

[0059] In an implementation form of a second communication device according to the second aspect, the embedded RRM reference signal has a first pattern or a second pattern different to the first pattern. An advantage with this implementation form is that the proposed solution can be used for control channel decoding enhancements. By enabling multiple possible configurations or patterns for the control resources embedded RRM reference signal and associating each with a subset of control channel candidates, the number of blind decoding can be reduced. In examples, two patterns may be used, one indicating the presence of a control channel signal for the first communication device and one indicating its absence. Consequently, the first communication device can skip control channel decoding when it detects the second pattern, indicating absence of a control channel for the first communication device.

[0060] According to a third aspect of the invention, the above mentioned and other objectives are achieved with a method for a first communication device, the method comprises: receiving a first control message from a second communication device, the first control message indicating at least one RRM measurement configuration; receiving a control resource during a DRX ON duration of the first communication device, the control resource comprising an embedded RRM reference signal; determining a RRM measurement based on the embedded RRM reference signal; and transmitting the RRM measurement to the second communication device based on the RRM measurement configuration.

[0061] The method according to the third aspect can be extended into implementation forms corresponding to the implementation forms of the first communication device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the first communication device.

[0062] The advantages of the methods according to the third aspect are the same as those for the corresponding implementation forms of the first communication device according to the first aspect.

[0063] According to a fourth aspect of the invention, the above mentioned and other objectives are achieved with a method for a second communication device, the method comprises: transmitting a first control message to a first communication device, the first control message indicating at least one RRM measurement configuration; transmitting a control resource during a DRX ON duration of the first communication device, the control resource comprising an embedded RRM reference signal; receiving a RRM measurement from the first communication device based on the RRM measurement configuration; and managing radio resources for the first communication device based on the RRM measurement.

[0064] The method according to the fourth aspect can be extended into implementation forms corresponding to the implementation forms of the second communication device according to the second aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the second communication device.

[0065] The advantages of the methods according to the fourth aspect are the same as those for the corresponding implementation forms of the second communication device according to the second aspect.

[0066] Embodiments of the invention also relate to a computer program, characterized in program code, which when run by at least one processor causes the at least one processor to execute any method according to embodiments of the invention. Further, embodiments of the invention also relate to a computer program product comprising a computer readable medium and the mentioned computer program, wherein the computer program is included in the computer readable medium, and may comprises one or more from the group of: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically erasable PROM (EEPROM), hard disk drive, etc.

[0067] Further applications and advantages of embodiments of the invention will be apparent from the following detailed description.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

[0070] - Fig. 1 shows a first communication device according to an embodiment of the invention;

[0071] - Fig. 2 shows a flow chart of a method for a first communication device according to an embodiment of the invention;

[0072] - Fig. 3 shows a second communication device according to an embodiment of the invention;

[0073] - Fig. 4 shows a flow chart of a method for a second communication device according to an embodiment of the invention;

[0074] - Fig. 5 shows a communication system according to an embodiment of the invention;

[0075] - Fig. 6 shows a signaling diagram according to embodiments of the invention;

[0076] - Fig. 7 shows RRM measurements shifting and the control resources embedded RRM RS; and

[0077] - Fig. 8 shows the control resources embedded RRM RS including one or more control channels.

[0078] DETAILED DESCRIPTION

[0079] In NR, a PDCCH candidate consists of a set of NR control channel elements (CCEs), corresponding to an aggregation level (AL). A PDCCH is transmitted in a control resource set (CORESET), which is defined as a set of resource element groups (REGs) under a given numerology. When receiving the PDCCH, the user equipment (UE) performs blind decoding for a set of PDCCH candidates, which are determined by, among others, search space (SS) sets configuration. Different type of SS sets is supported, i.e., common SS sets and UE-specific SS sets. Given the considerable complexity of PDCCH monitoring, the maximum number of monitored PDCCH candidates is upper bounded.

[0080] Radio resource management (RRM) measurements are performed by the UE on the serving and neighboring cells in radio resource control (RRC)-connected, RRC-idle and RRC-inactive states. RRM measurements are used for synchronization, loop convergence, cell reselection, beam selection / reselection, and paging monitoring. The aim is to ensure that the UE is always served by a cell with acceptable link quality.

[0081] In LTE, the synchronization signal has a periodicity of 5 ms and the cell reference signal (CRS) is transmitted in every DL subframe. Consequently, the UE can effectively receive and process data and RRM measurements within the UE discontinuous reception (DRX) ON duration. In NR, synchronization is based on synchronization signal blocks (SSBs) and measurements are confined within a SS / physical broadcast channel (PBCH) block measurement timing configuration (SMTC) window with possible periodicity values including {5, 10, 20, 40, 80, 160} ms.

[0082] The network provides the timing for SSB measurements using the SMTC window. Consequently, it is very difficult to align the SMTC window and the DRX ON duration for all UEs. In case of misalignment, the UE needs to be active during both the DRX ON duration and the SMTC window. This increases the power consumption at the UE when performing RRM measurements since dispersive operations, including SSB for RRM and SSB for time and frequency synchronization will lead to an increase in the power consumption of the UE.

[0083] Thus, two main issues need to be solved, i.e., on one hand extensive power consumption due to PDCCH decoding and, on the other hand, increased power consumption due to misalignment between SMTC window and DRX ON duration, forcing the UE to wake up outside DRX ON in order to perform RRM measurements. The extensive power consumption related to PDCCH decoding is due to blind decoding since the UE needs to attempt decoding of all possible PDCCH candidates, depending on the configuration. In case no PDCCH is received, power consumed by the UE when attempting PDCCH decoding is wasted. For RRM measurements, in the absence of an always-on-signal, e.g., cell specific reference Signal (CRS) in LEE, the UE can only perform its measurements when the RRM RS is received, which can be outside DRX ON duration. In this case, the UE needs to wake up to perform said RRM measurements. This increases power consumption due to state transition and increased activity time.

[0084] Therefore, it is herein proposed a solution comprising among other things RRM measurement configuration of communication devices for wireless networks. More particularly, a first communication device and a second communication device are configured to employ the present RRM measurement configuration scheme and control signaling thereof.

[0085] Fig. 1 shows a first communication device 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1, the first communication device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 is coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The first communication device 100 may be configured for wireless and / or wired communications in a communication system. The wireless communication capability may be provided with an antenna or antenna array 110 coupled to the transceiver 104, while the wired communication capability may be provided with a wired communication interface 112 e.g., coupled to the transceiver 104.

[0086] The processor 102 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, or one or more chipsets. The memory 106 may be a read-only memory, a random access memory (RAM), or a non-volatile RAM (NVRAM). The transceiver 104 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices, such as network nodes and network servers. The transceiver 104, memory 106 and / or processor 102 may be implemented in separate chipsets or may be implemented in a common chipset. That the first communication device 100 is configured to perform certain actions can in this disclosure be understood to mean that the first communication device 100 comprises suitable means, such as e.g., the processor 102 and the transceiver 104, configured to perform the actions.

[0087] According to embodiments of the invention, the first communication device 100 is configured to : receive a first control message 510 from a second communication device 300, the first control message 510 indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a discontinuous reception, DRX, ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; determine a RRM measurement based on the embedded RRM reference signal 550; and transmit the RRM measurement to the second communication device 300 based on the RRM measurement configuration.

[0088] Furthermore, in an embodiment of the invention, the first communication device 100 for a communication system 500 comprises a transceiver configured to: receive a first control message 510 from a second communication device 300, the first control message 510 indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a discontinuous reception, DRX, ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550. The first communication device 100 comprises a processor configured to determine a RRM measurement based on the embedded RRM reference signal 550. The first communication device 100 comprises a transceiver configured to: transmit the RRM measurement to the second communication device 300 based on the RRM measurement configuration. Moreover, in yet another embodiment of the invention, the first communication device 100 for a communication system 500 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to : receive a first control message 510 from a second communication device 300, the first control message 510 indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a discontinuous reception, DRX, ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; determine a RRM measurement based on the embedded RRM reference signal 550; and transmit the RRM measurement to the second communication device 300 based on the RRM measurement configuration.

[0089] Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a first communication device 100, such as the one shown in Fig. 1. The method 200 comprises: 202 receiving a first control message 510 from a second communication device 300, the first control message 510 indicating at least one radio resource management, RRM, measurement configuration; receiving 204 a control resource during a discontinuous reception, DRX, ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; determining 206 a RRM measurement based on the embedded RRM reference signal 550; and transmitting 208 the RRM measurement to the second communication device 300 based on the RRM measurement configuration.

[0090] Fig. 3 shows a second communication device 300 according to an embodiment of the invention. In the embodiment shown in Fig. 3, the second communication device 300 comprises a processor 302, a transceiver 304 and a memory 306. The processor 302 is coupled to the transceiver 304 and the memory 306 by communication means 308 known in the art. The second communication device 300 may be configured for wireless and / or wired communications in a communication system. The wireless communication capability may be provided with an antenna or antenna array 310 coupled to the transceiver 304, while the wired communication capability may be provided with a wired communication interface 312 e.g., coupled to the transceiver 304.

[0091] The processor 302 may be referred to as one or more general-purpose CPUs, one or more DSPs, one or more ASICs, one or more FPGAs, one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, one or more chipsets. The memory 306 may be a read-only memory, a RAM, or a NVRAM. The transceiver 304 may be a transceiver circuit, a power controller, or an interface providing capability to communicate with other communication modules or communication devices. The transceiver 304, the memory 306 and / or the processor 302 may be implemented in separate chipsets or may be implemented in a common chipset. That the second communication device 300 is configured to perform certain actions can in this disclosure be understood to mean that the second communication device 300 comprises suitable means, such as e.g., the processor 302 and the transceiver 304, configured to perform the actions.

[0092] According to embodiments of the invention, the second communication device 300 is configured to: transmit a first control message 510 to a first communication device 100, the first control message 510 indicating at least one RRM measurement configuration; transmit a control resource during a DRX ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; receive a RRM measurement from the first communication device 100 based on the RRM measurement configuration; and manage radio resources for the first communication device 100 based on the RRM measurement.

[0093] Furthermore, in an embodiment of the invention, the second communication device 300 for a communication system 500 comprises a transceiver configured to: transmit a first control message 510 to a first communication device 100, the first control message 510 indicating at least one RRM measurement configuration; transmit a control resource during a DRX ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; receive a RRM measurement from the first communication device 100 based on the RRM measurement configuration. The second communication device 300 comprises a processor configured to: manage radio resources for the first communication device 100 based on the RRM measurement.

[0094] Moreover, in yet another embodiment of the invention, the second communication device 300 for a communication system 500 comprises a processor and a memory having computer readable instructions stored thereon which, when executed by the processor, cause the processor to: transmit a first control message 510 to a first communication device 100, the first control message 510 indicating at least one RRM measurement configuration; transmit a control resource during a DRX ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; receive a RRM measurement from the first communication device 100 based on the RRM measurement configuration; and manage radio resources for the first communication device 100 based on the RRM measurement.

[0095] Fig. 4 shows a flow chart of a corresponding method 400 which may be executed in a second communication device 300, such as the one shown in Fig. 3. The method 400 comprises: transmitting 402 a first control message 510 to a first communication device 100, the first control message 510 indicating at least one RRM measurement configuration; transmitting 404 a control resource during a DRX ON duration of the first communication device 100, the control resource comprising an embedded RRM reference signal 550; receiving 406 a RRM measurement from the first communication device 100 based on the RRM measurement configuration; and managing 408 radio resources for the first communication device 100 based on the RRM measurement.

[0096] Fig. 5 shows a communication system 500 as a wireless network according to an embodiment of the invention. The communication system 500 in the disclosed embodiment comprises a first communication device 100 and a second communication device 300 configured to communicate and operate in the communication system 500. For simplicity, the shown communication system 500 only comprises one first communication device 100 and one second communication device 300. However, the communication system 500 may comprise any number of first communication devices 100 and any number of second communication devices 300 without deviating from the scope of the invention.

[0097] The first communication device 100 is in this example configured as a client device such as a UE, a traditional terminal, or a chip or chipset configured to execute embodiments of the invention. The second communication device 300 is on the other hand configured as a network access node such as a base station. The network access node may be part of a radio access network (RAN) and being capable of communication with a core network (NW) via a communication interface.

[0098] The first communication device 100 receives a first control message 510 from the second communication device 300 in a DL transmission. The first control message 510 as mentioned indicates at least one RRM measurement configuration to be used by the first communication device 100 for RRM measurements. The second communication device 300 transmits a control resource during a DRX ON duration of the first communication device 100. Since the first communication device 100 is wake it demodulates and decodes the control resource to derive an embedded RRM reference signal 550 therein. Based on the embedded RRM reference signal 550 and the RRM measurement configuration, the first communication device 100 determines a RRM measurement that is transmitted to the second communication device 300 in a UL transmission. Thus, the second communication device 300 can manage radio resources for the first communication device 100 using the received RRM measurement.

[0099] The proposed solution will impact how RRM measurements are managed in a wireless network and how the first communication device wakes up and how RRM reference signals are transmitted in the network. The proposed solution can e.g., be used for considered scenarios, in 5G NR or future wireless networks air interface. Further details related to embodiments of the invention will therefore be described in a 3GPP context. Thus, 3GPP terminology, definitions, expressions and system architecture will be used. Especially, the first communication device according to the invention may in these embodiments be configured to perform any of the described functions of a 3GPP UE. Correspondingly, the second communication device according to the invention may in these embodiments be configured to perform any of the described functions of a 3GPP gNB. It may however be noted that embodiments of the invention are not limited thereto.

[0100] Fig. 6 shows a signaling diagram according to embodiments of the invention. Especially, control signaling between the gNB 300 and the UE 100 according to aspects of the invention is illustrated in Fig. 6.

[0101] In step I in Fig. 6, the gNB 300 transmits a first control message 510 to the UE 100. The first control message 510 can be an RRC message or be part of system information blocks (SIBs).

[0102] In step II in Fig. 6, the UE 100 receives the first control message 510 from the gNB 300. By demodulating and decoding the first control message 510, the UE 100 derives the at least one RRM measurement configuration indicated by the first control message 510. The RRM measurement configuration is to be used for RRM measurement including how RRM measurement is determined and reported to the gNB 300 among other things.

[0103] In embodiments of the invention, the at least one RRM measurement configuration may also instruct the UE 100 to perform measurements outside the DRX ON duration. Thus, the RRM measurement configuration may indicate a SMTC window arranged outside the DRX ON duration. However, two main examples may be envisaged when the UE 100 does not have to perform such measurement outside the DRX ON duration but instead skipping such measurement thereby saving power and processing resources in the UE 100.

[0104] In a first example of RRM measurement skipping, the UE 100 is configured to skip performing the RRM measurement outside the DRX ON duration when a time offset of the embedded RRM RS 550 in relation to the SMTC window arranged outside the DRX ON duration is within a time period Tv. Thus, the UE 100 does not have to wake up within the time period Tvfrom the SMTC window. This is also the case when a RRM signal is arranged outside the DRX-ON duration with the time period Tvto perform other tasks. The time period Tvmay be determined considering the rate of UE mobility and the variation in radio conditions. The condition on the time gap between these signals guarantee that the variation in the outcome of measurements is minimal or acceptable, considering the dynamic nature of radio and channel conditions. Consequently, the UE 100 can skip performing RRM measurements outside the DRX ON duration without detrimental impact on the accuracy of the derived RRM measurements. Thus, the time period Tvmay be considered as a threshold value.

[0105] When the first example is employed, the gNB 300 may, in step III in Fig. 6, transmit a second control message 520 to the UE 100. The second control message 520 indicates the parameter Tv. In step IV in Fig. 6, the UE 100 thus receives the second control message 520 from the gNB. The UE 100 demodulates and decodes the second control message 520 and uses the parameter Tvconveyed in the second control message 520 to determine whether an RRM measurement outside DRX ON duration could be skipped or not. The gNB 300 can select the parameter Tvbased on the mobility patterns of UEs and radio channel conditions in order to guarantee that potential RRM measurements skipping will not degrade the quality of the derived RRM measurements. The second control message 520 may be RRC message or a MAC CE message depending on the application.

[0106] In a second example of RRM measurement skipping, the RRM measurement configuration indicates one or more requirements for skipping performing the RRM measurement, and the UE 100 is configured to skip performing the RRM measurement outside the DRX ON duration when the one or more requirements for performing the RRM measurement can be met using the RRM measurements based on the embedded RRM RS 550. Hence, if the RRM measurements based on the embedded RRM RS 550 is good enough no RRM measurement has to be performed outside the DRX ON duration.

[0107] The one or more requirements for skipping performing RRM measurements comprises one or more requirements in the group comprising:

[0108] • A measurement quantity which refers to measurement quantities such as RS index, received signal strength indicator (RSSI), synchronization signal based reference signal received power (SS-RSRP), synchronization signal based reference signal received quality (SS-RSRQ), Ll-RSRP and possible filtering applied to RRM measurements.

[0109] • A measurement object which refers to entities on which the UE 100 performs measurements which includes target cell frequency, target RS, and blacklisted and whitelisted cells.

[0110] • A measurement performance which includes minimum requirements to achieve a given performance target, such as the minimum number of measured RS, minimum measurement period, and minimum number of measurements used for filtering.

[0111] • A measurement criterion which includes measurement triggering criteria or events, conditions for measurement events such as thresholds on RSSI or relative strength between different cells, RS types for measurements, among others.

[0112] These requirements may be signaled to the UE 100 in the RRM measurement configuration. Thus, in embodiments of the invention, the RRM measurement configuration further indicates the one or more requirements.

[0113] Moreover, the transmission of the embedded RRM RS 550 by the gNB 300 may be preceded by control signaling between the gNB 300 and the UE 100 so as to inform about or request transmission of the embedded RRM RS 550.

[0114] In step V in Fig. 6, a network-initiated approach is shown in which the gNB 300 transmits a third control message 530 to the UE 100. The third control message 530 indicates the transmission of the embedded RRM RS 550. In step VI in Fig. 6, the UE 100 receives the third control message 530 from the gNB 300. By demodulating and decoding the third control message 530, the UE 100 knows that an embedded RRM RS 550 transmission will come from the gNB 300. The UE 100 therefore prepares for such transmission by determining which RRM measurements outside DRX ON duration that might be skipped, and in some cases adapt its approach to control channel decoding, by considering the embedded RRM RS pattern as additional information to restrict blind decoding in control resources wherein an RRM RS is embedded. The third control message 530 can be a downlink control information (DCI) or a DL MAC CE.

[0115] In step VII in Fig. 6, a UE-initiated approach is instead shown in which the UE 100 transmits a fourth control message 540 to the gNB 300. The fourth control message 540 indicates a request for the transmission of the embedded RRM RS 550. In step VIII in Fig. 6, the gNB 300 receives the fourth control message 540 from the UE 100. By demodulating and decoding the fourth control message 540, the gNB 300 is informed that the UE 100 is waiting for a transmission of the embedded RRM RS 550. Thus, the gNB 300 prepares for transmitting the embedded RRM RS 550. The fourth control message 540 can be an uplink control information (UCI) or UL MAC CE.

[0116] It is noted that both the third control message 530 and the fourth control message 540 may be used depending on the scenario. They are typically used when aperiodic or event triggered RRM measurements are leveraged. In this case, control resources embedded RRM RS is only transmitted and processed when the UE 100 or the gNB 300 determines a need for it.

[0117] In step IX in Fig. 6, the gNB 300 therefore transmits the embedded RRM RS 550 in the DRX ON duration of the UE 100. More precisely, the gNB 300 transmits a control resource comprising the embedded RRM RS 550. The embedded RRM reference signal 550 may be transmitted in a periodic, an aperiodic or a semi-persistent manner by the gNB 300. Consequently, multiple time domain behaviors can be supported for the control resources embedded RRM RS 550. This enables different approaches for managing the subsequent measurements e.g., opportunistic RRM measurement triggering and periodic RRM measurement skipping outside the DRX ON duration. Additionally, event-triggered RRM measurements and control resources embedded RRM RS transmissions are supported.

[0118] The embedded RRM RS 550 may be any of a SS, a preconfigured baseband sequence such as a gold sequence, or a channel state information reference signal (CSI-RS).

[0119] The control resource on the other hand may be a control resource set (CORSET). Two cases are possible, the CORSET is either a common CORSET for a plurality of UEs or a CORSET specific for a single UE. Cells can coordinate the allocation of UE common CORESETs so that control resources embedded RRM RS transmission can be received and measured within a confined time period.

[0120] The embedded RRM RS 550 may be cell-specific or transmission reception point (TRP) specific, enabling the use of subsequent measurements for mobility and cell selection.

[0121] In step X in Fig. 6, the UE 100 receives the embedded RRM RS 550 in the DRX ON duration. The UE 100 upon reception performs measurements) on the embedded RRM RS 550 to derive and determine RRM measurement.

[0122] That the RRM RS 550 is embedded may be understood such that the RRM RS 550 is transmitted within the control resources, whether the control resources contain a control channel, such as a PDCCH, or not. Depending on whether the control resources contain signals other than the RRM RS, the mapping of the RRM RS may differ.

[0123] The DRX ON duration of the UE 100 can be a time period in which the UE 100 is not in deep sleep state. DRX ON duration is typically given as part of DRX cycle configuration.

[0124] In step XI in Fig. 6, the UE 100 transmits the RRM measurements to the gNB 300. The RRM measurements can be transmitted in UCI, MAC CE or as part of higher layer signaling.

[0125] In step XII in Fig. 6, the gNB 300 receives the RRM measurements from the UE 100. The gNB 300 uses the received RRM measurement for managing radio resources in the wireless network for the UE 100. The management of radio resources may e.g., involve:

[0126] • Time frequency resource allocation including carrier activation / deactivation and time allocation considering cross link interference.

[0127] • Cell selection in the framework of carrier aggregation and load balancing.

[0128] • Mobility procedures and handovers between different cells.

[0129] Such management of radio resources are commonly specified by communication standards such as LTE and NR. Thus, the gNB 300 is configured to manage all radio resource procedures given by such standards using the RRM measurements received from the UE 100.

[0130] Furthermore, Fig. 7 shows an example of a proposed approach for RRM measurements shifting and control resources embedded RRM RS 550. More specifically, examples of frequency design layout according to embodiments of the invention is given. In Fig. 7 it is shown an example allocation of control resources embedded RRM RS 550 for multiple UEs and subsequent measurements skipping by certain UEs. It is seen that for UE #0 the RRM RS 550 is transmitted within the DRX ON period so no measurement skipping is needed and no RRM RS 550 is embedded in its control resources. For UE #1 and UE #2, control resources embedded RRM RS 550 can be received during their DRX ON periods. Consequently, both UE #1 and UE #2 can skip RRM measurements outside DRX ON period and shift their measurement time based on the expected reception of control resources embedded RRM RS 550. However, the same does not apply for UE #3 which is forced to wake up outside DRX ON period in order to perform RRM measurements. Consequently, once RRM measurements are done UE # 3 enters light sleep mode until the start of its DRX ON period wherein it has other channels to receive.

[0131] Fig. 8 shows an example of control resources embedded RRM RS 550 with two possible configured patterns where the left graph shows the first pattern and the right graph shows the second pattern. When the UE 100 receives the first pattern, it can assume that the CORESET does not comprises a PDCCH candidate. When the UE 100 on the other hand receives the second pattern it can consider that the CORESET comprises a PDCCH candidate. Note that both DMRS and control resources embedded RRM RS 550 can coexist in the same CORESET, as shown in Fig. 8. In this case, difference in the patterns of received control resources embedded RRM RS 550 may indicate the existence or absence of a control message of a control channel, e.g., a PDCCH, in the control resources.

[0132] Consequently, such an approach simplifies the decoding of the control channel for the UE 100. Thus, one RRM measurement configuration may indicate the existence of a control channel in the control resources, and another different RRM measurement configuration may indicate the absence of a control channel in the control resources. This may be identified with different patterns which is related to mapping of the embedded RRM RS 550 into such patterns. The configuration of the RRM RS 550 in a control channel element (CCE) or physical resource block (PRE) from the control resources can be different, depending on whether the CCE contains control channel payload or not.

[0133] Thus, in embodiments of the invention, the UE 100 is configured to decode a control channel in the control resource when the embedded RRM RS 550 has a first pattern. The UE 100 is also configured to skip decoding a control channel in the control resource when the embedded RRM RS 550 has a second pattern being different to the first pattern. Hence, the UE 100, by identifying the type of pattern, knows if there exists a control channel or not in the control resources. This difference in the RRM measurement configuration enables the UE 100 to speed up control channel decoding, as at least the aggregation level can be derived.

[0134] It may be noted that multiple different patterns may be used for indicating existence of control channels. The proposed scheme can be used for control channel decoding enhancements. By enabling multiple possible configurations or patterns for the control resources embedded RRM RS 550 and associating each with a subset of control channel candidates, the number of blind decoding can be reduced. In some cases, two patterns are used, one indicating the presence of a control signal for the UE 100 and one indicating its absence. Consequently, the UE 100 can skip control channel decoding when it detects the second pattern, indicating absence of control channel for the UE 100.

[0135] Furthermore, if the control channel is received in the control resources comprising the embedded RRM RS 550, the UE 100 may assume that the control channel is rate matched around the control resources embedded RRM RS 550. The control resources embedded RRM RS 550 can be transmitted in the control resources symbols with control channel. In this case, control channel rate matching is performed around the control resources embedded RRM RS 550.

[0136] A network access node herein may also be denoted as a radio network access node, an access network access node, an access point (AP), or a base station (BS), e.g., a radio base station (RBS), which in some networks may be referred to as transmitter, “gNB”, “gNodeB”, “eNB”, “eNodeB”, “NodeB” or “B node”, depending on the standard, technology and terminology used. The radio network access node may be of different classes or types such as e.g., macro eNodeB, home eNodeB or pico base station, based on transmission power and thereby the cell size. The radio network access node may further be a station, which is any device that contains an IEEE 802.11 -conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The radio network access node may be configured for communication in 3GPP related long term evolution (LTE), LTE-advanced, fifth generation (5G) wireless systems, such as new radio (NR) and their evolutions, as well as in IEEE related Wi-Fi, worldwide interoperability for microwave access (WiMAX) and their evolutions.

[0137] A client device herein may be denoted as a user device, a user equipment (UE), a mobile station, an internet of things (loT) device, a sensor device, a wireless terminal and / or a mobile terminal, and is enabled to communicate wirelessly in a wireless communication system, sometimes also referred to as a cellular radio system. The UEs may further be referred to as mobile telephones, cellular telephones, computer tablets or laptops with wireless capability. The UEs in this context may be, for example, portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and / or data, via a radio access network (RAN), with another communication entity, such as another receiver or a server. The UE may further be a station, which is any device that contains an IEEE 802.11 -conformant MAC and PHY interface to the WM. The UE may be configured for communication in 3GPP related LTE, LTE-advanced, 5G wireless systems, such as NR, and their evolutions, as well as in IEEE related Wi-Fi, WiMAX and their evolutions.

[0138] Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as previously mentioned a ROM, a PROM, an EPROM, a flash memory, an EEPROM, or a hard disk drive.

[0139] Moreover, it should be realized that the first communication device 100 and the second communication device 300 comprise the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing or implementing embodiments of the invention. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

[0140] Therefore, the processors) of the first communication device 100 and the second communication device 300 may comprise, e.g., one or more instances of a CPU, a processing unit, a processing circuit, a processor, an ASIC, a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising aplurality of processing circuits, such as e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

[0141] Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

CLAIMS1. A first communication device (100) configured to: receive a first control message (510) from a second communication device (300), the first control message (510) indicating at least one radio resource management, RRM, measurement configuration; receive a control resource during a discontinuous reception, DRX, ON duration of the first communication device (100), the control resource comprising an embedded RRM reference signal (550); determine a RRM measurement based on the embedded RRM reference signal (550); and transmit the RRM measurement to the second communication device (300) based on the RRM measurement configuration.

2. The first communication device (100) according to claim 1, wherein the RRM measurement configuration indicates a synchronization signal / physical broadcast channel, SS / PBCH, block measurement timing configuration, SMTC, window arranged outside the DRX ON duration; and wherein the first communication device (100) is configured to: skip performing the RRM measurement outside the DRX ON duration when a time offset of the embedded RRM reference signal (550) in relation to the SMTC window arranged outside the DRX ON duration is within a time period Tv3. The first communication device (100) according to claim 2, configured to: receive a second control message (520) from the second communication device (300), the second control message (520) indicating the time period Tv.

4. The first communication device (100) according to claim 3, wherein the second control message (520) is a radio resource control, RRC, message or a medium access control, MAC, control element, CE, message.

5. The first communication device (100) according to any one of claims 2 to 4, wherein the RRM measurement configuration indicates one or more requirements for performing the RRM measurement, and wherein the first communication device (100) is configured to: skip performing the RRM measurement outside the DRX ON duration when the one or more requirements for performing the RRM measurement can be met using the RRM measurements based on the embedded RRM reference signal (550).

6. The first communication device (100) according to claim 5, wherein the one or more requirements for performing RRM measurements comprises: a measurement quantity, a measurement object, a measurement performance, and a measurement criterion.

7. The first communication device (100) according to any one of the preceding claims, wherein the embedded RRM reference signal (550) is a SS, a preconfigured baseband sequence, or a channel state information reference signal, CSI-RS.

8. The first communication device (100) according to any one of the preceding claims, wherein the control resource is a control resource set, CORSET.

9. The first communication device (100) according to claim 8, wherein the CORSET is a common CORSET for a plurality of first communication devices (100).

10. The first communication device (100) according to any one of the preceding claims, wherein the embedded RRM reference signal (550) is cell-specific or transmission reception point, TRP, specific.

11. The first communication device (100) according to any one of the preceding claims, wherein the embedded RRM reference signal (550) is transmitted in a periodic, an aperiodic or a semi-persistent manner.

12. The first communication device (100) according to any one of the preceding claims, configured to: receive the embedded RRM reference signal (550) after reception of a third control message (530) from the second communication device (300), the third control message (530) indicating the transmission of the embedded RRM reference signal (550); or receive the embedded RRM reference signal (550) after transmission of a fourth control message (540) to the second communication device (300), the fourth control message (540) indicating a request for the transmission of the embedded RRM reference signal (550).

13. The first communication device (100) according to any one of the preceding claims, configured to: decode a control channel in the control resource when the embedded RRM reference signal (550) has a first pattern; and skip decoding a control channel in the control resource when the embedded RRM reference signal (550) has a second pattern different to the first pattern.

14. A second communication device (300) configured to: transmit a first control message (510) to a first communication device (100), the first control message (510) indicating at least one RRM measurement configuration; transmit a control resource during a DRX ON duration of the first communication device (100), the control resource comprising an embedded RRM reference signal (550); receive a RRM measurement from the first communication device (100) based on the RRM measurement configuration; and manage radio resources for the first communication device (100) based on the RRM measurement.

15. The second communication device (300) according to claim 14, wherein the RRM measurement configuration indicates a SMTC window arranged outside the DRX ON duration.

16. The second communication device (300) according to claim 15, configured to: transmit a second control message (520) to the first communication device (100), the second control message (520) indicating a time period Tvassociated with the SMTC window.

17. The second communication device (300) according to claim 16, wherein the second control message (520) is a RRC message or a MAC CE message.

18. The second communication device (300) according to any one of claims 15 to 17, wherein the RRM measurement configuration indicates one or more requirements for performing a RRM measurement.

19. The second communication device (300) according to claim 18, wherein the one or more requirements for performing the RRM measurement comprises: a measurement quantity, a measurement object, a measurement performance, and a measurement criterion.

20. The second communication device (300) according to any one of claims 14 to 19, wherein the embedded RRM reference signal (550) is a SS, a preconfigured baseband sequence, or a CSI-RS.

21. The second communication device (300) according to any one of claims 14 to 20, wherein the control resource is a CORSET.

22. The second communication device (300) according to claim 21 , wherein the CORSET is a common CORSET for a plurality of first communication devices (100).

23. The second communication device (300) according to any one of claims 14 to 22, wherein the embedded RRM reference signal (550) is cell-specific or TRP specific.

24. The second communication device (300) according to any one of claims 14 to 23, wherein the embedded RRM reference signal (550) is transmitted in a periodic, an aperiodic or a semi-persistent manner.

25. The second communication device (300) according to any one of claims 14 to 24, configured to: transmit a third control message (530) to the first communication device (100), the third control message (530) indicating the transmission of the embedded RRM reference signal (550); or receive a fourth control message (540) from the first communication device (100) prior to transmitting the first control message (510), the fourth control message (540) indicating a request for the transmission of the embedded RRM reference signal (550).

26. The second communication device (300) according to any one of claims 14 to 25, wherein the embedded RRM reference signal (550) has a first pattern or a second pattern different to the first pattern.

27. A method (200) for a first communication device (100), the method (200) comprising: receiving (202) a first control message (510) from a second communication device (300), the first control message (510) indicating at least one RRM measurement configuration; receiving (204) a control resource during a DRX ON duration of the first communication device (100), the control resource comprising an embedded RRM reference signal (550); determining (206) a RRM measurement based on the embedded RRM reference signal (550); and transmitting (208) the RRM measurement to the second communication device (300) based on the RRM measurement configuration.

28. A method (400) for a second communication device (300), the method (400) comprising: transmitting (402) a first control message (510) to a first communication device (100), the first control message (510) indicating at least one RRM measurement configuration; transmitting (404) a control resource during a DRX ON duration of the first communication device (100), the control resource comprising an embedded RRM reference signal (550); receiving (406) a RRM measurement from the first communication device (100) based on the RRM measurement configuration; and managing (408) radio resources for the first communication device (100) based on the RRM measurement.

29. A computer program with a program code for performing amethod according to claim 27 or 28 when the computer program runs on a computer.19

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