WO2019032032A1 - Adapting a measurement procedure based on muted rs transmissions - Google Patents

Abstract

Systems and methods are disclosed herein that relate to measurement procedures in a wireless communication system that uses reference signal muting. In some embodiments, a method of operation of a wireless device in a wireless communication system comprises obtaining information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device is less than the bandwidth of the cell. The method further comprises, performing a radio measurement on the reference signal using one or more measurement gaps if the reference signal is or is expected to be muted, and performing the radio measurement on the reference signal without a measurement gap if the reference signal is not muted or expected to be muted.

Description

ADAPTING A MEASUREMENT PROCEDURE BASED

ON MUTED RS TRANSMISSIONS

Related Applications

[0001] This application claims the benefit of provisional patent application serial number 62/544,383, filed August 1 1 , 2017, the disclosure of which is hereby incorporated herein by reference in its entirety.

Technical Field

[0002] The present disclosure relates to systems and methods of

measurement procedures in a wireless communication system.

Background

Machine Type Communication (MTC)

[0003] The Machine-to-Machine (M2M) communication (or MTC) is used for establishing communication between machines and between machines and humans. The communication may comprise exchange of data, signaling, measurement data, configuration information, etc. The device size may vary from that of a wallet to that of a base station. The M2M devices are quite often used for applications like sensing environmental conditions (e.g., temperature reading), metering or measurement (e.g. , electricity usage, etc.), fault finding or error detection, etc. In these applications the M2M devices are active very seldom but over a consecutive duration depending upon the type of service, e.g. about 200 milliseconds (ms) once every 2 seconds, about 500 ms every 60 minutes, etc. The M2M device may also do measurements on other frequencies or other Radio Access Technologies (RATs).

Low Complexity User Equipment (UE)

[0004] The MTC device is expected to be of low cost and low complexity. A low complexity UE envisages for M2M operation may implement one or more low cost features, like smaller downlink and uplink maximum transport block size (e.g., 1000 bits) and/or reduced downlink channel bandwidth of 1 .4 megahertz (MHz) for data channel (e.g., Physical Downlink Shared Channel (PDSCH)). A low cost UE may also comprise a Half-Duplex Frequency Division Duplexing (HD-FDD) and one or more of the following additional features: single receiver (1 Rx) at the UE, smaller downlink and/or uplink maximum transport block size (e.g., 1000 bits), and reduced downlink channel bandwidth of 1 .4 MHz for data channel. The low cost UE may also be termed a low complexity UE.

Coverage Enhancement (CE) in MTC

[0005] The path loss between the M2M device and the base station can be very large in some scenarios, such as when used as a sensor or metering device located in a remote location such as in the basement of a building. In such scenarios the reception of the signal from the base station is very challenging. For example, the path loss can be worse than 20 decibels (dB) compared to normal operation. In order to cope with such challenges, the coverage in uplink and/or in downlink has to be substantially enhanced. This is realized by employing one or a plurality of advanced techniques in the UE and/or in the radio network node for enhancing the coverage. Some non-limiting examples of such advanced techniques are (but are not limited to) transmit power boosting, repetition of transmitted signal, applying additional redundancy to the transmitted signal, use of advanced/enhanced receiver, etc. In general when employing such coverage enhancing techniques the M2M is regarded to be operating in coverage enhancing mode.

[0006] A low complexity UE (e.g., a UE with 1 Rx) may also be capable of supporting enhanced coverage mode of operation.

UE Measurements in Mobile Broadband (MBB) Long Term Evolution (LTE) and

Narrowband Internet of Things (NB-loT)

[0007] Radio measurements done by the UE are typically performed on the serving as well as on neighbor cells (e.g., Narrowband (NB) cells, NB Physical Resource Blocks (PRBs), etc.) over some known reference symbols or pilot sequences, e.g. NB Cell Specific Reference Signal (NB-CRS), NB Secondary Synchronization Signal (NSSS), NB Primary Synchronization Signal (NPSS), etc. The measurements are done on cells on an intra-frequency carrier, inter- frequency carrier(s), as well as on inter-RAT carriers(s) (depending upon the UE capability whether it supports that RAT). To enable inter-frequency and inter- RAT measurements for the UE requiring gaps, the network has to configure the measurement gaps.

[0008] The measurements are done for various purposes. Some example measurement purposes are: mobility, positioning, Self-Organizing Network (SON), Minimization of Drive Tests (MDT), Operation and Maintenance (O&M), network planning and optimization, etc. Examples of measurements in LTE are Physical Cell Identity (PCI) acquisition, Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Cell Global Identifier (CGI) acquisition, Reference Signal Time Difference (RSTD), UE Receive (RX)

Transmit (TX) time difference measurement, Radio Link Monitoring (RLM), which consists of Out of Synchronization (out of sync) detection and In Synchronization (in-sync) detection, etc. Channel State Information (CSI) measurements performed by the UE are used for scheduling, link adaptation, etc. by the network. Examples of CSI measurements or CSI reports are Channel Quality Indication (CQI), Precoding Matrix Indicator (PMI), Rank Indicator (Rl), etc. They may be performed on reference signals like Cell Specific Reference Signal (CRS), CSI Reference Signal (CSI-RS), or Demodulation Reference Signal (DMRS).

[0009] In order to identify an unknown cell (e.g., new neighbor cell) the UE has to acquire the timing of that cell and eventually the PCI. In legacy LTE operation the downlink subframe #0 and subframe #5 carry synchronization signals (i.e., both Primary Synchronization Signal (PSS) and Secondary

Synchronization Signal (SSS)). The synchronization signals used for NB-loT are known as NPSS and NSSS and their periodicity may be different from the LTE legacy synchronization signals. This is called cell search or cell identification. Subsequently the UE also measures RSRP and/or RSRQ of the newly identified cell in order to use itself and/or report the measurement to the network node. In total there are 504 PCIs in NB-loT RAT. The cell search is also a type of measurement. The measurements are done in all Radio Resource Control (RRC) states, i.e. in RRC idle and connected states. In RRC connected state the measurements are used by the UE for one or more tasks such as for reporting the results to the network node. In RRC idle the measurements are used by the UE for one or more tasks such as for cell selection, cell reselection, etc.

Discontinuous Reception (DRX) Cycle Operation

[0010] In LTE, DRX cycle is used to enable the UE to save its battery. The DRX cycle is used in RRC idle state but it can also be used in RRC connected state. Examples of lengths of DRX cycles currently used in RRC idle state are 320 ms, 640 ms, 1.28 seconds, and 2.56 seconds. Examples of lengths of DRX cycles currently used in RRC connected state may range from 2 ms to 2.56 seconds. The enhanced DRX (eDRX) cycles are expected to be very long, e.g. ranging from several seconds to several minutes and even up to one or more hours. Typical values of eDRX cycles may be between 4-10 minutes.

[0011] The DRX cycle is configured by the network node and is characterized by the following parameters:

• On duration: During the on duration of the DRX cycle, a timer called OnDurationTimer,' which is configured by the network node, is running.

This timer specifies the number of consecutive control channel subframes (e.g., Physical Downlink Control Channel (PDCCH), Enhanced PDCCH (ePDCCH) subframe(s)) at the beginning of a DRX cycle. It is also interchangeably called DRX ON period. More specifically, it is the duration in downlink subframes that the UE is awake after waking up from DRX to receive control channel (e.g., PDCCH, ePDCCH). If the UE successfully decodes the control channel (e.g., PDCCH, ePDCCH) during the ON duration then the UE starts a DRX inactivity timer (see below) and stays awake until its expiry. When the OnDurationTimer is running the UE is considered to be in DRX state of the DRX cycle. • DRX inactivity timer: It specifies the number of consecutive control channel (e.g., PDCCH, ePDCCH) subframe(s) after the subframe in which a control channel (e.g., PDCCH) indicates an initial uplink or downlink user data transmission for this Medium Access Control (MAC) entity. It is also configured by the network node. When the

DRX inactivity timer is running the UE is considered to be in non-DRX state, i.e. no DRX is used.

• Active time: This time is the duration during which the UE monitors the control channel (e.g., PDCCH, ePDCCH). In other words this is the total duration during which the UE is awake. This includes the "on- duration" of the DRX cycle, the time during which the UE is performing continuous reception while the inactivity timer has not expired, and the time the UE is performing continuous reception while waiting for a downlink retransmission after one Hybrid Automatic Repeat Request (HARQ) Round Trip Time (RTT). The minimum active time is equal to the length of an on duration, and the maximum active time is undefined (infinite).

[0012] The DRX ON and DRX OFF durations of the DRX cycle are shown in Figure 1. The DRX operation with more detailed parameters in LTE is illustrated in Figure 2.

Summary

[0013] Systems and methods are disclosed herein that relate to measurement procedures in a wireless communication system that uses reference signal muting. In some embodiments, a method of operation of a wireless device in a wireless communication system comprises obtaining information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device is less than the bandwidth of the cell. The method further comprises performing a radio measurement on the reference signal using one or more measurement gaps if the reference signal is or is expected to be muted, and performing the radio measurement on the reference signal without a measurement gap if the reference signal is not muted or expected to be muted.

[0014] In some embodiments, the method further comprises determining that the radio frequency bandwidth of the wireless device is less than the bandwidth of the cell. In some embodiments, the method further comprises using a result of the radio measurement for one or more operational tasks.

[0015] In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth that is less than the bandwidth of the cell. In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to not be transmitted in a certain part of the bandwidth cell.

[0016] In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted only in a certain part of the bandwidth cell. Further, in some embodiments, the certain part of the bandwidth of the cell is a defined number of central physical resource blocks of the bandwidth of the cell. Further, in some embodiments, the defined number of central physical resource blocks is six.

[0017] In some embodiments, the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises information that reveals a muting pattern for the reference signal in the cell.

[0018] In some embodiments, the reference signal is completely or partially muted over time. In some embodiments, muting of the reference signal varies over time.

[0019] In some embodiments, obtaining the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises receiving the information from a network node. In some embodiments, obtaining the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises receiving the information directly from a serving network node of the wireless device.

[0020] Embodiments of a wireless device for a wireless system are also disclosed. In some embodiments, a wireless device for a wireless system is adapted to obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device is less than the bandwidth of the cell. The wireless device is further adapted to perform a radio measurement on the reference signal using one or more measurement gaps if the reference signal is or is expected to be muted, and perform the radio measurement on the reference signal without a

measurement gap if the reference signal is not muted or expected to be muted.

[0021] In some embodiments, a wireless device for a wireless system comprises one or more transceivers and circuitry associated with the one or more transceivers whereby the wireless device is operable to: obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device is less than the bandwidth of the cell; perform a radio measurement on the reference signal using one or more measurement gaps if the reference signal is or is expected to be muted; and perform the radio measurement on the reference signal without a measurement gap if the reference signal is not muted or expected to be muted.

[0022] Embodiments of a method of operation of a network node in a wireless system are also disclosed. In some embodiments, a method of operation of a network node in a wireless system comprises configuring a wireless device with a measurement configuration for enabling the wireless device to perform a radio measurement on a cell, wherein a radio frequency bandwidth of the wireless device is less than a bandwidth of the cell. The method further comprises receiving a result of the radio measurement performed by the wireless device using a first procedure that uses one or more measurement gaps if a reference signal transmitted on the cell is or is expected to be muted or a second procedure that does not use a measurement gap if the reference signal transmitted on the cell is not muted or expected to be muted.

[0023] In some embodiments, the method further comprises using the result of the radio measurement for one or more operational tasks.

[0024] In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth that is less than the bandwidth of the cell. In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to not be transmitted in a certain part of the bandwidth cell.

[0025] In some embodiments, the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted only in a certain part of the bandwidth cell. Further, in some embodiments, the certain part of the bandwidth of the cell is a defined number of central physical resource blocks of the bandwidth of the cell. Further, in some embodiments, the defined number of central physical resource blocks is six.

[0026] In some embodiments, the reference signal is completely or partially muted over time. In some embodiments, muting of the reference signal varies over time.

[0027] In some embodiments, the method further comprises providing, to the wireless device, information on whether the reference signal transmitted in the cell is or is expected to be muted. Further, in some embodiments, the network node is a serving network node of the wireless device, and providing the information to the wireless device comprises providing the information directly to the wireless device.

[0028] Embodiments of a network node for a wireless system are also disclosed. In some embodiments, a network node for a wireless system is adapted to configure a wireless device with a measurement configuration for enabling the wireless device to perform a radio measurement on a cell, wherein a radio frequency bandwidth of the wireless device is less than a bandwidth of the cell. The network node is further adapted to receive a result of the radio measurement performed by the wireless device using a first procedure that uses one or more measurement gaps if a reference signal transmitted on the cell is or is expected to be muted or a second procedure that does not use a

measurement gap if the reference signal transmitted on the cell is not muted or expected to be muted.

[0029] In some embodiments, a network node for a wireless system comprises at least one processor and memory comprising instructions executable by the at least one processor whereby the network node is operable to: configure a wireless device with a measurement configuration for enabling the wireless device to perform a radio measurement on a cell, wherein a radio frequency bandwidth of the wireless device is less than a bandwidth of the cell; and receive a result of the radio measurement performed by the wireless device using a first procedure that uses one or more measurement gaps if a reference signal transmitted on the cell is or is expected to be muted or a second procedure that does not use a measurement gap if the reference signal transmitted on the cell is not muted or expected to be muted.

Brief Description of the Drawings

[0030] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0031] Figure 1 illustrates Discontinuous Reception (DRX) ON and DRX OFF periods;

[0032] Figure 2 illustrates DRX cycle operation in Long Term Evolution (LTE);

[0033] Figure 3 illustrates one example of a wireless system in which embodiments of the present disclosure may be implemented;

[0034] Figure 4 is a flow chart showing the procedure involved in the wireless device according to some embodiments of the present disclosure;

[0035] Figure 5 is an Illustration of User Equipment device (UE) Radio

Frequency (RF) bandwidth and cell bandwidth location in the frequency domain;

[0036] Figure 6 is a flow chart that illustrates the operation of a network node according to some embodiments of the present disclosure;

[0037] Figures 7 and 8 illustrate two examples;

[0038] Figures 9 and 10 illustrate example embodiments of a wireless device; and

[0039] Figures 1 1 through 13 illustrate example embodiments of a network node. Detailed Description

[0040] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0041] In some embodiments a more general term "network node" is used and it can correspond to any type of radio network node or any network node, which communicates with a User Equipment device (UE) and/or with another network node. Examples of network nodes are a Node B, a Master enhanced or evolved Node B (eNB) (MeNB), a Secondary eNB (SeNB), a network node belonging to a Master Cell Group (MCG) or Secondary Cell Group (SCG), a base station, a Multi-Standard Radio (MSR) radio node such as a MSR base station, an eNB, a network controller, a Radio Network Controller (RNC), a Base Station Controller (BSC), a relay, a donor node controlling relay, a Base Transceiver Station (BTS), an Access Point (AP), transmission points, transmission nodes, a Remote Radio Unit (RRU), a Remote Radio Head (RRH), nodes in a Distributed Antenna System (DAS), a core network node (e.g., a Mobile Switching Center (MSC), a Mobility Management Entity (MME), etc.), Operation and Maintenance (O&M), Operations Support System (OSS), a Self-Organizing Network (SON), a positioning node (e.g., Evolved Serving Mobile Location Center (E-SMLC)), Minimization of Drive Tests (MDT), etc.

[0042] In some embodiments the non-limiting terms UE or a wireless device are used interchangeably. The UE herein can be any type of wireless device capable of communicating with a network node or another UE over radio signals. The UE may also be a radio communication device, a target device, a Device-to-Device (D2D) UE, a machine type UE or a UE capable of Machine-to- Machine (M2M) communication, a low-cost and/or low-complexity UE, a sensor equipped with a UE, a tablet, mobile terminals, a smart phone, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), Universal Serial Bus (USB) dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-loT) device, etc.

[0043] Also in some embodiments the generic term "radio network node" is used. It can be any kind of a radio network node which may comprise any of a base station, a radio base station, a BTS, a BSC, a network controller, a RNC, an eNB, a Node B, a Multi-Cell/Multicast Coordination Entity (MCE), a relay node, an AP, a radio AP, a RRU, or a RRH.

[0044] In some embodiments, the UE may be configured with a Primary Cell (PCell) and a Primary Secondary Cell (PSCell) or with a PCell, PSCell, and one or more Secondary Cells (SCells) such as in dual connectivity and/or carrier aggregation. The configured cells are UE specific, aka serving cells of the UE.

[0045] In some embodiments, the term "monitoring" is used and it may correspond to any type of measurement, e.g. path, signal strength, signal quality, Reference Signal Received Power (RSRP), cell search, etc.

[0046] In some embodiments, the term "layer" is used and it may correspond to any carrier frequency on which one or more cells operate and can transmit and/or receive signals. The UE can perform one or more measurements on signals of one or more cells belong to the carrier frequency. The layer is also called frequency layer, carrier frequency layer, etc. Each carrier frequency is addressed or indicated to the UE by an absolute channel number called Absolute Radio Frequency (RF) Channel Number (ARFCN), e.g. Universal Terrestrial Radio Access (UTRA) ARFCN (UARFCN) in Universal Mobile

Telecommunications System (UMTS), Evolved ARFCN (EARFCN) in Long Term Evolution (LTE), etc.

[0047] The UE is served by a serving cell which has already been identified by the UE. The UE further identifies at least one other cell, which may be called a target cell or a neighbor cell. In some embodiments, the serving cell and the neighbor cell are served or managed by the first network node and the second network node, respectively. In some embodiments the serving cell and the neighbor cell are served or managed by the same network node, e.g. a first network node.

[0048] The embodiments are applicable for a UE in a low or in a high activity state. Examples of low activity state are Radio Resource Control (RRC) idle state, idle mode, etc. Examples of high activity state are RRC CONNECTED state, active mode, active state, etc. The UE may be configured to operate in Discontinuous Reception (DRX) or in non-DRX. If configured to operate in DRX, it may still operate according to non-DRX as long as it receives new

transmissions from the network node.

[0049] The UE may operate under normal coverage, extended coverage, or extreme coverage with respect to its serving cell or the target cell on which the measurement is to be performed. These coverage classes are also

interchangeably called normal coverage and enhanced coverage in some cases. The UE may also operate in a plurality of coverage levels, e.g. normal coverage, enhanced coverage level 1 , enhanced coverage level 2, enhanced coverage level 3, and so on.

[0050] The coverage level may be expressed in terms of:

• received signal quality and/or received signal strength at the UE with regard to its serving cell and/or

· received signal quality and/or received signal strength at the serving cell with regard to the UE.

[0051] Examples of signal quality are Signal to Noise Ratio (SNR), Signal to Interference plus Noise Radio (SINR), Channel Quality Indication (CQI),

Reference Signal Received Quality (RSRQ), Cell Specific Reference Signal (CRS) Es/lot, Shared Channel (SCH) Es/lot, etc. Examples of signal strength are path loss, RSRP, SCH_RP, etc. The notation Es/lot is defined as the ratio of:

• Es, which is the received energy per Resource Element (RE) (power normalized to the subcarrier spacing) during the useful part of the symbol, i.e. excluding the cyclic prefix, at the UE antenna connector, to · lot, which is the received power spectral density of the total noise and interference for a certain RE (power integrated over the RE and normalized to the subcarrier spacing) as measured at the UE antenna connector.

[0052] Consider an example of two coverage levels defined with regard to signal quality (e.g., SNR) at the UE comprising:

· Coverage Enhancement (CE) level 1 (CE1 ) comprising SNR > -6

decibels (dB) at the UE with regard to its serving cell; and

• CE level 2 (CE2) comprising -12 dB < SNR < -6 dB at the UE with regard to its serving cell.

[0053] Consider another example of four coverage levels comprising:

· CE level 1 (CE1 ) comprising SNR > -6 dB at the UE with regard to its serving cell;

• CE level 2 (CE2) comprising -12 dB < SNR < -6 dB at the UE with regard to its serving cell;

• CE level 3 (CE3) comprising -15 dB < SNR < -12 dB at the UE with regard to its serving cell; and

• CE level 4 (CE4) comprising -18 dB < SNR < -15 dB at the UE with regard to its serving cell.

[0054] In the above example the CE1 may also interchangeably be called normal coverage level, baseline coverage level, reference coverage level, legacy coverage level, etc. On the other hand, CE2-CE4 may be termed enhanced coverage or extended coverage levels.

[0055] The embodiments are described in a context of NB-loT devices. However, the embodiments are applicable to any Radio Access Technology (RAT) or multi-RAT systems where a measurement configuration is adapted based on channel quality of the measured cells.

[0056] In legacy systems, a wireless device can perform Radio Resource Management (RRM) measurement anywhere within its UE RF bandwidth because the Reference Signals (RSs) are always transmitted, i.e., the RSs are transmitted across the full cell bandwidth in all transmit time intervals or subframes. However, this may not be possible in future releases (e.g., Third Generation Partnership Project (3GPP) Release (Rel) 15) because the RSs can be muted (e.g., transmitted only within a certain part of the cell bandwidth) and the UE RF bandwidth can be smaller than the cell bandwidth. As such, the legacy RRM measurement procedures are unsuitable in this scenario.

[0057] In some embodiments of the present disclosure, a wireless device is configured by a network node to perform one or more radio measurements on at least a RS transmitted by a first cell (celM ) in a scenario in which 1 ) an RF bandwidth of the wireless device is less than an RF bandwidth of celM and 2) celM mutes or is expected to mute the RS, at least in certain parts of the bandwidth of celM during certain time resources. In this scenario, the wireless device performs the radio measurements on the RS of cell 1 : 1 ) using

measurement gaps when the RSs are muted or are expected to be muted in celM or 2) without measurement gaps when the RSs are not muted or are not expected to be muted in celM . The wireless device determines whether or not the RS is muted or expected to be muted in celM by any one or more of the following means: predefined rule(s), autonomous determination, by receiving information from a network node or from another wireless device, history, or past statistics, etc. The above measurement rules can be predefined or configured at the UE by the network node, and can be realized by the UE adapting its measurement procedure based on whether or not the RS is muted or expected to be muted in the measured cell (celM ).

[0058] Embodiments of the present disclosure enable neighbor cell measurements, but more importantly also serving cell measurement, to work properly when the network employs RSs that are muted in cells (e.g., transmitted only over reduced bandwidth).

[0059] Figure 3 illustrates one example of a wireless communication system 10 in which embodiments of the present disclosure may be implemented. In this example, the wireless communication system 10 is a cellular communications network and, in particular, is a 3GPP LTE or New Radio (NR) cellular

communications network that supports RS muting. As illustrated, the wireless communication system 10 includes a number of wireless devices 12, which are also referred to herein as wireless communication devices 12 or UEs 12. In addition, the wireless communication system 10 includes a Radio Access Network (RAN) that includes a number of radio access nodes 14 (e.g., eNBs or NR base stations (gNBs)) serving corresponding coverage areas or cells 16. The radio access nodes 14 are connected to a core network 18, which includes a number of core network nodes (not shown), as will be appreciated by one of skill in the art.

[0060] Figure 4 is a flow chart that illustrates the operation of a wireless device 12 according to some embodiments of the present disclosure. Optional steps are indicated by dashed lines. The wireless device 12 is served by a network node and obtains information related to RS transmission and adapts its measurement procedure to enable RRM measurement of serving and neighbor cells. As illustrated, the wireless device 12 performs the following steps:

- Step 100: Determine that the RF bandwidth of the wireless device 12 is smaller than a RF bandwidth (BW1 ) of a first cell (celM )

- Step 102: Obtain information on whether a RS transmitted in celM which is used by the wireless device 12 for performing a radio measurement is muted or expected to be muted, which is also referred to herein as the RS being "reduced." In some embodiments, the RS is muted if the RS is transmitted over a second bandwidth (BW2), where BW2 < BW1

- Step 104: Perform radio measurement using one of the following two measurement procedures as follows:

o Step 104A: A first procedure (A) in which the radio measurement is performed using measurement gaps in the first cell (celM ) provided that the RS is muted in that cell.

o Step 104B: A second procedure (B) in which the radio measurement is performed without measurement gaps in the first cell (celM ) provided that the RS is not muted in that cell.

- Step 106 (optional): Use the performed radio measurement for one or more operational tasks.

The steps illustrated in Figure 4 are described in more detail below. [0061] Step 100: In this step, the wireless device 12 determines the relation between its RF bandwidth and the RF bandwidth (i.e., the cell bandwidth) of the first cell (celM ), which is referred to herein as BW1. Specific examples of celM are the serving cell of the wireless device 12, a neighbor cell of the wireless device 12, a reference cell, etc. Examples of serving cells are PCell, PSCell, SCell, etc. As used herein, the RF bandwidth of the wireless device 12 (also referred to as wireless device bandwidth or UE bandwidth) means the maximum RF bandwidth supported by the wireless device 12 or the RF bandwidth configured for the wireless device 12 by a network node. In the former case, the RF bandwidth of the wireless device 12 is known to the wireless device 12 since this is related to the RF architecture of the wireless device 12. In the latter case, the wireless device 12 determines its RF bandwidth based on the bandwidth configuration information received from the network node. The wireless device 12 determines the celM bandwidth by receiving information from the network node. The cell bandwidth is transmitted in a broadcast channel. For example, by reading the broadcast channel (e.g., Physical Broadcasting Channel (PBCH) or Narrowband (NB) PBCH (NPBCH)) of a cell, the wireless device 12 can determine the bandwidth of that cell. There are two possible scenarios:

1. UE RF bandwidth < celM bandwidth

2. UE RF bandwidth = celM bandwidth

The embodiments described herein apply for the first scenario, an example of which is illustrated in Figure 5. Figure 5 shows that the UE RF bandwidth is different from the center frequency of the serving cell bandwidth. This means that the wireless device 12 will need to re-tune to the center frequency e.g., the central six Physical Resource Blocks (PRBs)) in order to measure on the synchronization signals (Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS)) and to receive broadcast channels like PBCH to obtain Master Information Block (MIB). In legacy systems, the RRM

measurement can be performed anywhere in the UE RF bandwidth, i.e. scenario 1 is valid. [0062] Step 102: In this step, the wireless device 12 obtains information on whether a RS is transmitted in celM and used by the wireless device 12 for performing a radio measurement is:

• Muted in celM or

· Expected to be muted in celM

[0063] Muting in this context means that the RSs are not transmitted over the entire cell bandwidth. Instead, they are transmitted only in a certain part of the cell bandwidth, which is referred to herein as a second bandwidth (BW2).

Information on whether muting of RS is or expected to be employed in a cell can be obtained:

• directly from the serving network node, e.g. using dedicated RRC

signaling or broadcast information;

• from other nodes in the network such as a core network node; or

• from other wireless devices in its vicinity.

[0064] The obtained information may also reveal information on whether the RS muting is employed in the time domain, the frequency domain, or in both. Muting in the frequency domain means that the RS can be transmitted in only a subset of PRBs of celM 's bandwidth, e.g. RSs are transmitted in the central six PRBs of celM bandwidth while they are muted over the remaining PRBs of celM bandwidth. However, the RS transmission bandwidth can vary with time. Time domain muting means that the RS can be muted completely or partly over time. In one example, the muting of the RS is applied or is expected to be only in a first set of time resources (R1 ) of celM while no RS muting is applied in a second set of time resources (R2) of cell2. The set of R1 may either consist of a consecutive set of time resources or a non-consecutive set of time resources. Similarly, the set of R2 may either consist of a consecutive set of time resources or a non-consecutive set of time resources. Examples of time resources are radio frames, subframes, Transmit Time Interval (TTI), slot, mini- slot, symbols, etc. The time resources R1 and R2 are non-overlapping. In one specific example, muting of the RS is applied or expected to be applied in all subframes of a radio frame of celM over one or a set of radio frames which can be consecutive or non-consecutive. In another specific example, the muting of the RS is applied or expected to be applied in subset of subframes within any set of the radio frames of celM ; for example, the RS muting is applied only in subframes 0 and 5 or is applied in subframes 0, 4, 5, and 9. In yet another example, the RS muting is applied over a duration of N1 number of radio frames within Nt number of radio frames, while no RS muting is applied over the remaining duration of N2 number of radio frames within Nt where Nt = N1 + N2.

[0065] The obtained information may also reveal detailed information on the muting pattern of RS transmission on celM over the time and frequency domain.

[0066] Step 104: If the received information (obtained in step 100) indicates that the RF bandwidth of the wireless device 12 is not smaller than the

bandwidth of celM (BW1 ), then the wireless device 12 may carry out the one or more radio measurements on at least RSs of celM using a legacy procedure (i.e., the embodiment described herein does not apply). For example, in the legacy procedure the wireless device 12 does not require any measurement gaps for performing measurements on the serving cell.

[0067] In this step, the wireless device 12 whose RF bandwidth is less than the RF bandwidth of celM based on the obtained information about the RS muting in the cell as described in step 102 decides whether to perform the radio measurement on at least RSs (e.g., CRS) transmitted by celM according to a first measurement procedure (A) or a second measurement procedure (B), which are illustrated as steps 104A and 104B in Figure 4.

[0068] Examples of radio measurements are RSRP, RSRQ, RS SINR (RS- SINR), CRS Es/lot, SCH Es/loT, UE Receive-Transmit (RX-TX) time difference, etc. More examples are given above.

[0069] According to procedure A, the wireless device 12 does the radio measurement using measurement gaps regardless of the cell type. For example, if celM is the serving cell, the serving network node has to provide the

measurement gaps to the wireless device 12 during which the wireless device 12 re-tunes to the part of bandwidth where the RSs are transmitted by celM and does the radio measurement over the RS in that part of the bandwidth. Unlike the legacy UE behavior, the wireless device 12 may also need gaps for the serving cell measurement to be able to receive the RS which may otherwise be muted in the RF bandwidth of the wireless device 12. Similarly, unlike the legacy UE behavior, the network node has to provide/configure the wireless device 12 with gaps for enabling the wireless device 12 to also measure on the serving cell. This is not necessary in legacy systems since the UE can assume RS transmission anywhere within the cell bandwidth, i.e. always available within the RF bandwidth of the wireless device 12. In yet another exemplary

implementation, the wireless device 12 is pre-configured with measurement gaps. However, the wireless device 12 only uses the measurement gaps for performing the measurements when the wireless device 12 has to apply the measurement procedure A. Otherwise, when applying the measurement procedure B, the wireless device 12 does not use or apply the pre-configured measurement gaps. The network node knows whether and when celM applies RS muting. This enables the network node to know whether the wireless device 12 is applying the measurement procedure A or the measurement procedure B for performing the radio measurements over a certain time period.

[0070] According to procedure B, the wireless device 12 carries out the radio measurement on RS transmitted by celM without using any measurement gaps. Here, the wireless device 12 can assume that RSs are always available within the RF bandwidth of the wireless device 12.

[0071] The wireless device 12 determines whether to carry out the

measurements based on the procedure A or procedure B according to the following rules:

• If the received information (obtained in step 102) indicates that the RSs are muted or expected to be muted in celM on whose signals the wireless device 12 is expected to measure, then the wireless device 12 applies procedure A for carrying out the one or more radio measurements. • If the received information (obtained in step 102) indicates that the RSs are not muted in celM on whose signals the wireless device 12 is expected to measure, then the wireless device 12 applies procedure B for carrying out the one or more radio measurements.

[0072] By applying the measurement procedure A or B based on obtained data, radio measurements in both neighbor cells but also on the serving cell are enabled. Serving cell measurements are crucial as they are used for various tasks (such as cell selection/re-selection, Radio Link Monitoring (RLM), SON, mobility, positioning, etc.) which may otherwise fail.

[0073] Step 106 (optional): In this step, the wireless device 12 uses the received radio measurement results for performing one or more operational tasks. Examples of such tasks are reporting the results to the network node and using the results for autonomous actions in the wireless device 12 (e.g., cell change, positioning, etc.).

[0074] Figure 6 is a flow chart that illustrates the operation of a network node (e.g., a radio access node 14 such as, e.g., an eNB) according to some embodiments of the present disclosure. Optional steps are indicated by dashed lines. As illustrated, the network node performs the following steps:

- Step 200: Configure the wireless device 12 with a measurement

configuration for enabling the wireless device 12 to perform a radio measurement on at least a first cell (celM ).

- Step 202: Receive results of the radio measurement performed by the wireless device 12 using one of the following two measurement procedures:

o A first procedure (A) in which the radio measurement is performed using measurement gaps in the first cell provided that the RS is muted in that cell,

o A second procedure (B) in which the radio measurement is performed without measurement gaps in the first cell provided that the RS is not muted in that cell. - Step 204 (Optional): Use the received radio measurement results for performing one or more operational tasks.

Each of these steps is discussed in more detail below.

[0075] Step 200: In this step, the network node configures the wireless device 12 with a measurement configuration for enabling the wireless device 12 to perform a radio measurement on at least a first cell (e.g., celM , serving cell).

[0076] The measurement configuration may include information on

measurement gaps, i.e. whether the wireless device 12 is expected to assume measurement gaps to perform the measurements. This also means whether the wireless device 12 is expected to use the first measurement procedure (A) or a second procedure (B) as described above in relation to step 104.

[0077] It may also include information on the type of measurement it is expected to perform, such as RSRP, RSRQ, RS-SINR, etc. It may also include information on how frequently the wireless device 12 is expected to perform such measurement, e.g. whether the measurement is periodic, event-triggered, or a period event-triggered measurement, etc.

[0078] Step 202: In this step the network node receives the results of the performed radio measurements from the wireless device 12 based on at least one of the two measurement procedures (procedure A and B as described above in relation to step 104). Measurements performed using procedure A are done using measurement gaps regardless of the cell type, e.g. serving cell, while the measurements done using procedure B are carried out without using any measurement gaps. Typically, the measurement performed using the gaps may take a longer time since the wireless device 12 needs to re-tune its frequency and the gaps can only occur with a certain frequency. This means the

measurement delay may be longer if they are performed according to procedure A compared to procedure B.

[0079] The network node typically has information on whether the RS muting is applied in its cell or any other cells which the wireless device 12 has been configured to measure on. From this information it directly or indirectly knows about what measurement delay to expect. [0080] The received measurement result may also be tagged by the wireless device 12 indicating whether they were performed assuming gaps or not, i.e. procedure A or B. If tagging indicates procedure A, then the network node may assume a certain measurement delay which is longer than the other tags.

[0081] The description and examples about the wireless device

measurements using different procedures described above in relation to step 104 are also applicable to this step.

[0082] Step 204 (Optional): In this step, the network node uses the results of the measurements (e.g., events, periodic measurements, etc.) which are reported by the wireless device 12 to a node, e.g. to its serving cell. The result of the measurements (e.g., events) can be used by the network node for one or various operational tasks. Examples of the operational tasks are: positioning, scheduling of signals, uplink and/or downlink power control, MDT, measurement collection, obtaining measurement statistics, creating maps of measurements associated with UE locations, SON, resource optimization, mobility, UE transmit timing control, timing advance, etc.

[0083] A few examples of some embodiments of the present disclosure will now be provided.

[0084] According to the legacy measurement procedure, the wireless device 12 can perform the RRM measurements any time in the RF bandwidth of the wireless device 12 without using any gaps since the RSs are always available. However, if the RF bandwidth of the wireless device 12 is less than the RF bandwidth of the measured celM (e.g., the serving cell) and the RSs are transmitted only in the center frequency, the wireless device 12 may also need gaps also for the serving cell measurement. One specific example is when the wireless device 12 is configured with DRX ON durations, and the wireless device 12 is re-tuning to the center frequency during the DRX OFF durations in order to perform measurements. In such scenario, there is risk that the period where the wireless device 12 has re-tuned to the center frequency and DRX ON durations (where the wireless device 12 is expected to monitor the downlink control channel in the RF bandwidth of the wireless device 12) partly or fully overlap. Such overlap can destroy at least part of the ON durations, meaning that wireless device 12 is not able to receive anything in those resources since the wireless device 12 is not retuning in a controlled manner and the network is unaware of it. This problem may occur more frequently when the wireless device 12 is configured with short DRX cycles and can be avoided by configuring the wireless device 12 with measurement gaps also for the serving cell

measurements.

[0085] Example 1 illustrated in Figure 7 shows that part of the DRX ON durations can be destroyed.

[0086] Example 2 illustrated in Figure 8 shows that part of the "ramp up'Valso known as "warm up" period, can be destroyed. The "warm up" period occurs just before the DRX ON duration where the wireless device 12 needs to prepare its receiver after being off for some time. Since this is not coordinated with the "retuning to the center" duration, this can cause a problem which is solved by configuring gaps.

[0087] Figure 9 is a schematic block diagram of the wireless device 12, or UE 12, according to some embodiments of the present disclosure. As illustrated, the wireless device 12 includes circuitry 20 comprising one or more processors 22 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), and/or the like) and memory 24. The wireless device 12 also includes one or more transceivers 26 each including one or more transmitters 28 and one or more receivers 30 coupled to one or more antennas 32. In some

embodiments, the functionality of the wireless device 12 described herein may be implemented in hardware (e.g., via hardware within the circuitry 20 and/or within the processor(s) 22) or be implemented in a combination of hardware and software (e.g., fully or partially implemented in software that is, e.g., stored in the memory 24 and executed by the processor(s) 22).

[0088] In some embodiments, a computer program including instructions which, when executed by the at least one processor 22, causes the at least one processor 22 to carry out at least some of the functionality of the wireless device 12 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

[0089] Figure 10 is a schematic block diagram of the wireless device 12, or UE 12, according to some other embodiments of the present disclosure. The wireless device 12 includes one or more modules 34, each of which is

implemented in software. The module(s) 34 provide the functionality of the wireless device 12 described herein (e.g., as described with respect to Figure 4).

[0090] Figure 1 1 is a schematic block diagram of a network node 36 (e.g., a radio access node 14 such as, for example, an eNB or gNB or a core network node) according to some embodiments of the present disclosure. As illustrated, the network node 36 includes a control system 38 that includes circuitry comprising one or more processors 40 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like) and memory 42. The control system 38 also includes a network interface 44. In embodiments in which the network node 36 is a radio access node 14, the network node 36 also includes one or more radio units 46 that each include one or more transmitters 48 and one or more receivers 50 coupled to one or more antennas 52. In some embodiments, the functionality of the network node 36 described above may be fully or partially implemented in software that is, e.g., stored in the memory 42 and executed by the processor(s) 40.

[0091] Figure 12 is a schematic block diagram that illustrates a virtualized embodiment of the network node 36 (e.g., the radio access node 14 or a core network node) according to some embodiments of the present disclosure. As used herein, a "virtualized" network node 36 is a network node 36 in which at least a portion of the functionality of the network node 36 is implemented as a virtual component (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, the network node 36 optionally includes the control system 38, as described with respect to Figure 1 1. In addition, if the network node 36 is the radio access node 14, the network node 36 also includes the one or more radio units 46, as described with respect to Figure 1 1. The control system 38 (if present) is connected to one or more processing nodes 54 coupled to or included as part of a network(s) 56 via the network interface 44. Alternatively, if the control system 38 is not present, the one or more radio units 46 (if present) are connected to the one or more processing nodes 54 via a network interface(s). Alternatively, all of the functionality of the network node 36 described herein may be implemented in the processing nodes 54. Each processing node 54 includes one or more

processors 58 (e.g., CPUs, ASICs, DSPs, FPGAs, and/or the like), memory 60, and a network interface 62.

[0092] In this example, functions 64 of the network node 36 (e.g., the functions of the network nodes described above with respect to, e.g., Figure 6) described herein are implemented at the one or more processing nodes 54 or distributed across the control system 38 (if present) and the one or more processing nodes 54 in any desired manner. In some particular embodiments, some or all of the functions 64 of the network node 36 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 54. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 54 and the control system 38 (if present) or alternatively the radio unit(s) 46 (if present) is used in order to carry out at least some of the desired functions. Notably, in some embodiments, the control system 38 may not be included, in which case the radio unit(s) 46 (if present) communicates directly with the processing node(s) 54 via an

appropriate network interface(s).

[0093] In some particular embodiments, higher layer functionality (e.g., layer 3 and up and possibly some of layer 2 of the protocol stack) of the network node 36 may be implemented at the processing node(s) 54 as virtual components (i.e., implemented "in the cloud") whereas lower layer functionality (e.g., layer 1 and possibly some of layer 2 of the protocol stack) may be implemented in the radio unit(s) 46 and possibly the control system 38. [0094] In some embodiments, a computer program including instructions which, when executed by the at least one processor 40, 58, causes the at least one processor 40, 58 to carry out the functionality of the network node 36 or a processing node 54 according to any of the embodiments described herein is provided. In some embodiments, a carrier containing the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as the memory 42, 60).

[0095] Figure 13 is a schematic block diagram of the network node 36 according to some other embodiments of the present disclosure. The network node 36 includes one or more modules 66, each of which is implemented in software. The module(s) 66 provide the functionality of the network node 36 described herein (e.g., the functionality of a corresponding one of the network nodes described in relation to, e.g., Figure 6).

[0096] While not being limited thereto, some example embodiments of the present disclosure are provided below.

[0097] Embodiment 1 : A method of operation of a wireless device (12) in a wireless communication system (10), comprising: obtaining (102) information on whether a reference signal transmitted on a bandwidth of a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell; if the reference signal is or is expected to be muted, performing (104A) a radio measurement on the reference signal using one or more measurement gaps; and if the reference signal is not muted or expected to be muted, performing (104B) the radio measurement on the reference signal without a measurement gap.

[0098] Embodiment 2: The method of embodiment 1 further comprising determining (100) that the radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell.

[0099] Embodiment 3: The method of embodiment 1 or 2 further comprising using (106) a result of the radio measurement for one or more operational tasks. [0100] Embodiment 4: The method of any one of embodiments 1 to 3 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth (BW2) that is less than the bandwidth of the cell.

[0101] Embodiment 5: A wireless device (12) for a wireless system, the wireless device (12) adapted to perform the method of any one of embodiments 1 to 4.

[0102] Embodiment 6: A wireless device (12) for a wireless system, comprising: one or more transceivers (26); and circuitry (20) associated with the one or more transceivers (26) whereby the wireless device (12) is operable to perform the method of any one of embodiments 1 to 4.

[0103] Embodiment 7: A wireless device (12) for a wireless system, comprising: one or more modules (34) operable to perform the method of any one of embodiments 1 to 4.

[0104] Embodiment 8: A method of operation of a network node in a wireless system, comprising: configuring (200) a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio

measurement on a cell, wherein a radio frequency bandwidth of the wireless device (12) is less than a bandwidth of the cell; and receiving (202) a result of the radio measurement performed by the wireless device (12) using a first procedure that uses one or more measurement gaps if a reference signal transmitted on the cell is or is expected to be muted or a second procedure that does not use a measurement gap if the reference signal transmitted on the cell not muted or expected to be muted.

[0105] Embodiment 9: The method of embodiment 8 further comprising using (204) the result of the radio measurement for one or more operational tasks.

[0106] Embodiment 10: The method of embodiment 8 or 9 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth (BW2) that is less than the bandwidth of the cell. [0107] Embodiment 1 1 : A network node for a wireless system, the network node adapted to perform the method of any one of embodiments 8 to 10.

[0108] Embodiment 12: A network node for a wireless system, comprising: at least one processor (40, 58); and memory (42, 60) comprising instructions executable by the at least one processor (40, 58) whereby the network node is operable to perform the method of any one of embodiments 8 to 10.

[0109] Embodiment 13: A network node for a wireless system, comprising one or more modules (66) operable to perform the method of any one of embodiments 8 to 10.

[0110] The following acronyms are used throughout this disclosure.

• 3GPP Third Generation Partnership Project

• AP Access Point

• ARFCN Absolute Radio Frequency Channel Number

• ASIC Application Specific Integrated Circuit

• BSC Base Station Controller

• BTS Base Transceiver Station

• CE Coverage Enhancement

• CGI Cell Global Identifier

• CPE Customer Premises Equipment

• CPU Central Processing Unit

• CQI Channel Quality Indication

• CRS Cell Specific Reference Signal

• CSI Channel State Information

• CSI-RS Channel State Information Reference Signal

• D2D Device-to-Device

• DAS Distributed Antenna System

• dB Decibel

• DMRS Demodulation Reference Signal

• DRX Discontinuous Reception

• DSP Digital Signal Processor • EARFCN Evolved Absolute Radio Frequency Channel Number

• eDRX Enhanced Discontinuous Reception

• eNB Enhanced or Evolved Node B

• ePDCCH Enhanced Physical Downlink Control Channel

• E-SMLC Evolved Serving Mobile Location Center

• FPGA Field Programmable Gate Array

. gNB New Radio Base Station

• HARQ Hybrid Automatic Repeat Request

• HD-FDD Half-Duplex Frequency Division Duplexing

• loT Internet of Things

• LEE Laptop Embedded Equipment

• LME Laptop Mounted Equipment

• LTE Long Term Evolution

• M2M Machine-to-Machine

• MAC Medium Access Control

• MBB Mobile Broadband

• MCE Multi-Cell/Multicast Coordination Entity

• MCG Master Cell Group

• MDT Minimization of Drive Tests

• MeNB Master Enhanced or Evolved Node B

• MHz Megahertz

• MIB Master Information Block

• MME Mobility Management Entity

• ms Millisecond

• MSC Mobile Switching Center

• MSR Multi-Standard Radio

• MTC Machine Type Communication

• NB Narrowband

• NB-CRS Narrowband Cell Specific Reference Signal

• NB-loT Narrowband Internet of Things • NPBCH Narrowband Physical Broadcasting Channel

• NPSS Narrowband Primary Synchronization Signal

• NR New Radio

• NSSS Narrowband Secondary Synchronization Signal

• O&M Operation and Maintenance

• OSS Operations Support System

• PBCH Physical Broadcasting Channel

• PCell Primary Cell

• PCI Physical Cell Identity

• PDCCH Physical Downlink Control Channel

• PDSCH Physical Downlink Shared Channel

• PMI Precoding Matrix Indicator

• PRB Physical Resource Block

• PSCell Primary Secondary Cell

• PSS Primary Synchronization Signal

• RAT Radio Access Technology

• RAN Radio Access Network

• RE Resource Element

• Rel Release

• RF Radio Frequency

• Rl Rank Indicator

• RLM Radio Link Monitoring

• RNC Radio Network Controller

• RRC Radio Resource Control

• RRH Remote Radio Head

• RRM Radio Resource Management

• RRU Remote Radio Unit

• RS Reference Signal

• RSRP Reference Signal Received Power

• RSRQ Reference Signal Received Quality RS-SINR Reference Signal Signal to Interference plus Noise

Ratio

RSTD Reference Signal Time Difference

RTT Round Trip Time

RX Receive

SCell Secondary Cell

SCG Secondary Cell Group

SCH Shared Channel

SeNB Secondary Enhanced or Evolved Node B

SINR Signal to Interference plus Noise Radio

SNR Signal to Noise Ratio

SON Self-Organizing Network

SSS Secondary Synchronization Signal

TTI Transmit Time Interval

TX Transmit

UARFCN Universal Terrestrial Radio Access

Absolute Radio Frequency Channel Number

UE User Equipment

UMTS Universal Mobile Telecommunications System

USB Universal Serial Bus

UTRA Universal Terrestrial Radio Access

[0111] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims What is claimed is:

1. A method of operation of a wireless device (12) in a wireless

communication system (10), comprising:

obtaining (102) information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than a bandwidth of the cell;

if the reference signal is or is expected to be muted, performing (104A) a radio measurement on the reference signal using one or more measurement gaps; and

if the reference signal is not muted or expected to be muted, performing (104B) the radio measurement on the reference signal without a measurement gap.

2. The method of claim 1 further comprising determining (100) that the radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell.

3. The method of claim 1 or 2 further comprising using (106) a result of the radio measurement for one or more operational tasks.

4. The method of any one of claims 1 to 3 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth that is less than the bandwidth of the cell.

5. The method of any one of claims 1 to 3 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to not be transmitted in a certain part of the bandwidth of the cell.

6. The method of any one of claims 1 to 3 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted only in a certain part of the bandwidth of the cell.

7. The method of claim 6 wherein the certain part of the bandwidth of the cell is a defined number of central physical resource blocks of the bandwidth of the cell.

8. The method of claim 7 wherein the defined number of central physical resource blocks is six.

9. The method of any one of claims 1 to 8 wherein the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises information that reveals a muting pattern for the reference signal in the cell.

10. The method of any one of claims 1 to 9 wherein the reference signal is completely or partially muted over time.

1 1 . The method of any one of claims 1 to 9 wherein muting of the reference signal varies over time.

12. The method of any one of claims 1 to 1 1 wherein obtaining (102) the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises receiving the information from a network node.

13. The method of any one of claims 1 to 1 1 wherein obtaining (102) the information on whether the reference signal transmitted in the cell is or is expected to be muted comprises receiving the information directly from a serving network node of the wireless device (12).

14. The method one of claims 1 to 13 wherein the cell is a serving cell of the wireless device (12).

15. A wireless device (12) for a wireless communication system (10), the wireless device (12) adapted to:

obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell;

if the reference signal is or is expected to be muted, perform a radio measurement on the reference signal using one or more measurement gaps; and if the reference signal is not muted or expected to be muted, perform the radio measurement on the reference signal without a measurement gap.

16. The wireless device (12) of claim 15 wherein the wireless device (12) is further adapted to perform the method of any one of claims 2 to 14.

17. A wireless device (12) for a wireless communication system (10), comprising:

one or more transceivers (26); and

circuitry (20) associated with the one or more transceivers (26) whereby the wireless device (12) is operable to:

obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell;

if the reference signal is or is expected to be muted, perform a radio measurement on the reference signal using one or more measurement gaps; and

if the reference signal is not muted or expected to be muted, perform the radio measurement on the reference signal without a measurement gap.

18. The wireless device (12) of claim 16 wherein, via the circuitry (20), the wireless device (12) is further operable to perform the method of any one of claims 2 to 14.

19. A wireless device (12) for a wireless communication system (10), comprising:

one or more modules (34) comprising:

an obtaining module operable to obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than the bandwidth of the cell; and

a performing module operable to:

perform a radio measurement on the reference signal using one or more measurement gaps if the reference signal is or is expected to be muted; and

perform the radio measurement on the reference signal without a measurement gap if the reference signal is not muted or expected to be muted.

20. The wireless device (12) of claim 19 wherein the one or more modules (34) are further operable to perform the method of any one of claims 2 to 14.

21 . A method of operation of a network node in a wireless communication system (10), comprising:

obtaining (102) information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of the wireless device (12) is less than a bandwidth of the cell;

if the reference signal is or is expected to be muted, configuring (200) a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal using one or more measurement gaps; and if the reference signal is not muted or expected to be muted, configuring (200) a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal without a measurement gap.

22. The method of claim 21 further comprising:

receiving (202) a result of the radio measurement performed by the wireless device (12); and

using (204) the result of the radio measurement for one or more operational tasks.

23. The method of claim 21 or 22 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted on a second bandwidth that is less than the bandwidth of the cell.

24. The method of any one of claims 21 to 23 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to not be transmitted in a certain part of the bandwidth of the cell.

25. The method of any one of claims 21 to 23 wherein the reference signal is or is expected to be muted if the reference signal is or is expected to be transmitted only in a certain part of the bandwidth of the cell.

26. The method of claim 25 wherein the certain part of the bandwidth of the cell is a defined number of central physical resource blocks of the bandwidth of the cell.

27. The method of claim 26 wherein the defined number of central physical resource blocks is six.

28. The method of any one of claims 21 to 27 wherein the reference signal is completely or partially muted over time.

29. The method of any one of claims 21 to 27 wherein muting of the reference signal varies over time.

30. The method of any one of claims 21 to 29 further comprising:

providing, to the wireless device (12), information on whether the reference signal transmitted in the cell is or is expected to be muted.

31 . The method of claim 30 wherein the network node is a serving network node of the wireless device (12), and providing the information to the wireless device (12) comprises providing the information directly to the wireless device (12).

32. The method one of claims 21 to 31 wherein the cell is a serving cell of the wireless device (12).

33. A network node for a wireless communication system (10), the network node adapted to:

obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of a wireless device (12) is less than a bandwidth of the cell;

if the reference signal is or is expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal using one or more measurement gaps; and

if the reference signal is not muted or expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal without a measurement gap.

34. The network node of claim 33 wherein the network node is further adapted to perform the method of any one of claims 22 to 32.

35. A network node for a wireless communication system (10), comprising: at least one processor (40, 58); and

memory (42, 60) comprising instructions executable by the at least one processor (40, 58) whereby the network node is operable to:

obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of a wireless device (12) is less than a bandwidth of the cell;

if the reference signal is or is expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal using one or more measurement gaps; and

if the reference signal is not muted or expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal without a measurement gap.

36. The network node of claim 35 wherein, by execution of the instructions by the at least one processor (40, 58), the network node is further operable to perform the method of any one of claims 22 to 32.

37. A network node for a wireless communication system (10), comprising: one or more modules (66) comprising:

obtain information on whether a reference signal transmitted in a cell is or is expected to be muted, where a radio frequency bandwidth of a wireless device (12) is less than a bandwidth of the cell;

if the reference signal is or is expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal using one or more measurement gaps; and

if the reference signal is not muted or expected to be muted, configure a wireless device (12) with a measurement configuration for enabling the wireless device (12) to perform a radio measurement on the reference signal without a measurement gap.

38. The network node of claim 37 wherein the one or more modules (66) are further operable to perform the method of any one of claims 22 to 32.